Publications by authors named "Weizhen Chen"

44 Publications

Psoas Muscle Density Predicts Occurrences of Hepatic Encephalopathy in Patients Receiving Transjugular Intrahepatic Portosystemic Shunts within 1 year.

Cardiovasc Intervent Radiol 2021 Sep 14. Epub 2021 Sep 14.

Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Wenzhou Medical University, No. 2, Fuxue Lane, Wenzhou, 325000, China.

Purpose: We aimed to assess the efficacy of psoas density (PD) for predicting hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) procedures.

Methods: Data were collected from patients who underwent TIPS procedures at a single institution between 2013 and 2019. PD was manually measured using software on unenhanced CT scans at the level of third lumbar vertebra. Laboratory and physical examination data were collected within 24 h after admission in order to compare the differences between patients with and without post-TIPS HE.

Results: A total of 251 patients were included in this study. Among these patients, 77 (30.7%) developed post-TIPS HE within one year after TIPS creation. The threshold of PD for predicting HE was 51.24 Hounsfield unit (HU). PD values less than this threshold were correlated with an increased risk of HE (hazard ratio 0.92; 95% CI 0.89-0.95, P < 0.001). The area under the receiver operating characteristic curve (AUROC) of PD was 0.743 (95% CI 0.685-0.796), which was superior to Model for End-stage Liver Disease (MELD) (0.569, P = 0.007), albumin-bilirubin score (ALBI) (0.641, P = 0.018), and Child-Pugh score (0.583, P = 0.003).

Conclusion: PD measurement showed good HE predictive value in cirrhotic patients who underwent TIPS. This measure also performed better than MELD, ALBI and Child-Pugh.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00270-021-02961-8DOI Listing
September 2021

Low Cd-accumulating rice intercropping with Sesbania cannabina L. reduces grain Cd while promoting phytoremediation of Cd-contaminated soil.

Sci Total Environ 2021 Aug 10;800:149600. Epub 2021 Aug 10.

College of Natural Resources and Environment, South China Agricultural University / Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture of the People's Republic of China, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture / Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China. Electronic address:

Paddy field pollution with Cd has become a serious problem and poses threat to public health. Intercropping is new good agricultural practice for phytoremediation in Cd contaminated soil. Field and pot experiments were conducted to examine the effects of intercropping low Cd-accumulating rice with Sesbania cannabina on plant growth, uptake of Cd by the intercropping system, and rhizosphere microecology, and to evaluate the potential remediation of Cd contaminated soil and safety production of rice. The results of in the field experiment show that, in intercropping system, the concentration of Cd in the grain of rice (0.18 mg kg) was below the threshold level permitted by the National Food Safety Standard of China (GB 2762-2017, 0.20 mg kg). Furthermore, the yield per plant of rice in intercropping system significantly (P < 0.05) increased by 19.71%. At the same time, the bio-concentration amount (BCA) of Cd per plant of Sesbania cannabina in intercropping system significantly (P < 0.05) increased by 46.15%. The metal removal equivalent ratio (MRER) of Cd was 1.11, indicating that the intercropping system had advantage in Cd removal. In the pot experiment, the rice intercropped with Sesbania cannabina under no barrier (IN) treatment significantly (P < 0.05) decreased the content of rhizosphere organic acids (oxalic and malic acids), and significantly (P < 0.05) increased the rhizosphere pH value and total iron plaque concentration on the root surface compared to the intercropping with plastic barrier (IN+P) treatment, which could significantly (P < 0.05) decreased the available Cd content in rhizosphere soil and the accumulation of Cd in rice organs. With this study we demonstrated that lower rhizosphere organic acids and higher iron plaque can obstruct and decreased the Cd absorbed by rice in a rice-Sesbania cannabina intercropping system. We conclude that intercropping rice with Sesbania cannabina is a promising and cost-effective agricultural practice for safe crop production and for phytoremediation in Cd-contaminated paddy soil.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.scitotenv.2021.149600DOI Listing
August 2021

Mammary Development and Breast Cancer: a Notch Perspective.

J Mammary Gland Biol Neoplasia 2021 Aug 10. Epub 2021 Aug 10.

Department of Orthopaedics, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China.

Mammary gland development primarily occurs postnatally, and this unique process is complex and regulated by systemic hormones and local growth factors. The mammary gland is also a highly dynamic organ that undergoes profound changes at puberty and during the reproductive cycle. These changes are driven by mammary stem cells (MaSCs). Breast cancer is one of the most common causes of cancer-related death in women. Cancer stem cells (CSCs) play prominent roles in tumor initiation, drug resistance, tumor recurrence, and metastasis. The highly conserved Notch signaling pathway functions as a key regulator of the niche mediating mammary organogenesis and breast neoplasia. In this review, we discuss mechanisms by which Notch contributes to breast carcinoma pathology and suggest potentials for therapeutic targeting of Notch in breast cancer. In summary, we provide a comprehensive overview of Notch functions in regulating MaSCs, mammary development, and breast cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10911-021-09496-1DOI Listing
August 2021

Gallium (Ga)-strontium (Sr) layered double hydroxide composite coating on titanium substrates for enhanced osteogenic and antibacterial abilities.

J Biomed Mater Res A 2021 Jul 29. Epub 2021 Jul 29.

Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.

Bacterial infection and poor osteogenic capacity can result in the loosing or failure of titanium (Ti)-based implants in the clinic. Therefore, it is urgent to design an effective approach to enhance the osteogenic property and restrict bacterial activity. In this study, a layered double hydroxide (LDH) composed of Ga and Sr ions on Ti substrates by a hydrothermal method, then calcined in 250°C and denoted as LDH250. The scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were confirmed that the LDH films were successfully formed on the Ti substrates. Importantly, the obtained LDH films can induce an alkaline microenvironment around the Ti surface and regulate the behaviors of osteogenic cells and bacteria. In vitro cellular experiments, the LDH250 can enhance the differentiation of both MC3T3-E1 cells and osteoblasts, stimulate alkaline phosphatase activity (ALP), collagen secretion, and mineralization levels. Meanwhile, antimicrobial assay against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) demonstrated that the LDH250 samples had strong antibacterial abilities, which attributed to the release profile of Ga could act as a "Trojan horse" to destroy the bacterial iron metabolism, inducing of local alkaline environment, and producing reactive oxygen species. Hence, this study provides an effective method for reducing antibacterial infection and enhancing the bone integrative capacity of Ti-based implants for orthopedic applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbm.a.37284DOI Listing
July 2021

Baicalin Promotes Mammary Gland Development via Steroid-Like Activities.

Front Cell Dev Biol 2021 6;9:682469. Epub 2021 Jul 6.

Department of Orthopaedics, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Medical Research Institute, Wuhan University, Wuhan, China.

Baicalin, the main flavonoid component extracted from roots, has a variety of biological activities and is therefore used in the treatment of many kinds of diseases. However, whether baicalin affects the normal development of tissues and organs is still unclear. Here, using a mouse mammary gland model, we investigated the effects of baicalin on the expansion of mammary stem cells (MaSCs) and mammary development, as well as breast cancer progression. Interestingly, we found that baicalin administration significantly accelerates duct elongation at puberty, and promotes alveolar development and facilitates milk secretion during pregnancy. Furthermore, self-renewal of MaSCs was significantly promoted in the presence of baicalin. Moreover, in a tumor xenograft model, baicalin promoted tumor growth of the MDA-MB-231 cell line, but suppressed tumor growth of the ZR-751 cell line. Mechanistically, baicalin can induce expression of the protein C receptor, while inhibiting the expression of the estrogen receptor. Transcriptome analysis revealed that baicalin is involved in signaling pathways related to mammary gland development, immune response, and cell cycle control. Taken together, our results from comprehensive investigation of the biological activity of baicalin provide a theoretical basis for its rational clinical application.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcell.2021.682469DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8290356PMC
July 2021

Assessment of the Diagnostic Ability of Four Detection Methods Using Three Sample Types of COVID-19 Patients.

Front Cell Infect Microbiol 2021 7;11:685640. Epub 2021 Jun 7.

Department of Laboratory Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.

Background: Viral nucleic acid detection is considered the gold standard for the diagnosis of coronavirus disease 2019 (COVID-19), which is caused by SARS-CoV-2 infection. However, unsuitable sample types and laboratory detection kits/methods lead to misdiagnosis, which delays the prevention and control of the pandemic.

Methods: We compared four nucleic acid detection methods [two kinds of reverse transcription polymerase chain reactions (RT-PCR A: ORF1ab and N testing; RT-PCRB: only ORF1ab testing), reverse transcription recombinase aided amplification (RT-RAA) and droplet digital RT-PCR (dd-RT-PCR)] using 404 samples of 72 hospitalized COVID-19 patients, including oropharyngeal swab (OPS), nasopharyngeal swabs (NPS) and saliva after deep cough, to evaluate the best sample type and method for SARS-CoV-2 detection.

Results: Among the four methods, dd-RT-PCR exhibited the highest positivity rate (93.0%), followed by RT-PCR B (91.2%) and RT-RAA (91.2%), while the positivity rate of RT-PCR A was only 71.9%. The viral load in OPS [24.90 copies/test (IQR 15.58-129.85)] was significantly lower than that in saliva [292.30 copies/test (IQR 20.20-8628.55)] and NPS [274.40 copies/test (IQR 33.10-2836.45)]. In addition, if OPS samples were tested alone by RT-PCR A, only 21.4% of the COVID-19 patients would be considered positive. The accuracy of all methods reached nearly 100% when saliva and NPS samples from the same patient were tested simultaneously.

Conclusions: SARS-CoV-2 nucleic acid detection methods should be fully evaluated before use. High-positivity rate methods such as RT-RAA and dd-RT-PCR should be considered when possible. Furthermore, saliva after deep cough and NPS can greatly improve the accuracy of the diagnosis, and testing OPS alone is not recommended.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcimb.2021.685640DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8216554PMC
June 2021

The Mechanical Properties and Damage Evolution of UHPC Reinforced with Glass Fibers and High-Performance Polypropylene Fibers.

Materials (Basel) 2021 May 9;14(9). Epub 2021 May 9.

Shandong Hi-Speed Company Limited, Jinan 250000, China.

Due to the sharp and corrosion-prone features of steel fibers, there is a demand for ultra-high-performance concrete (UHPC) reinforced with nonmetallic fibers. In this paper, glass fiber (GF) and the high-performance polypropylene (HPP) fiber were selected to prepare UHPC, and the effects of different fibers on the compressive, tensile and bending properties of UHPC were investigated, experimentally and numerically. Then, the damage evolution of UHPC was further studied numerically, adopting the concrete damaged plasticity (CDP) model. The difference between the simulation values and experimental values was within 5.0%, verifying the reliability of the numerical model. The results indicate that 2.0% fiber content in UHPC provides better mechanical properties. In addition, the glass fiber was more significant in strengthening the effect. Compared with HPP-UHPC, the compressive, tensile and flexural strength of GF-UHPC increased by about 20%, 30% and 40%, respectively. However, the flexural toughness indexes , and of HPP-UHPC were about 1.2, 2.0 and 3.8 times those of GF-UHPC, respectively, showing that the toughening effect of the HPP fiber is better.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ma14092455DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8125961PMC
May 2021

Effects of angiotensin II receptor blocker usage on viral load, antibody dynamics, and transcriptional characteristics among COVID-19 patients with hypertension.

J Zhejiang Univ Sci B 2021 Apr;22(4):330-340

Department of Laboratory Medicine, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.

Epidemiological evidence suggests that patients with hypertension infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are at increased risk of acute lung injury. However, it is still not clear whether this increased risk is related to the usage of renin-angiotensin system (RAS) blockers. We collected medical records of coronavirus disease 2019 (COVID-19) patients from the First Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou, China), and evaluated the potential impact of an angiotensin II receptor blocker (ARB) on the clinical outcomes of COVID-19 patients with hypertension. A total of 30 hypertensive COVID-19 patients were enrolled, of which 17 were classified as non-ARB group and the remaining 13 as ARB group based on the antihypertensive therapies they received. Compared with the non-ARB group, patients in the ARB group had a lower proportion of severe cases and intensive care unit (ICU) admission as well as shortened length of hospital stay, and manifested favorable results in most of the laboratory testing. Viral loads in the ARB group were lower than those in the non-ARB group throughout the disease course. No significant difference in the time of seroconversion or antibody levels was observed between the two groups. The median levels of soluble angiotensin-converting enzyme 2 (sACE2) in serum and urine samples were similar in both groups, and there were no significant correlations between serum sACE2 and biomarkers of disease severity. Transcriptional analysis showed 125 differentially expressed genes which mainly were enriched in oxygen transport, bicarbonate transport, and blood coagulation. Our results suggest that ARB usage is not associated with aggravation of COVID-19. These findings support the maintenance of ARB treatment in hypertensive patients diagnosed with COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1631/jzus.B2000730DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8042529PMC
April 2021

Janus 2D titanium nitride halide TiNXY (X, Y = F, Cl, or Br, and X ≠ Y) monolayers with giant out-of-plane piezoelectricity and high carrier mobility.

Phys Chem Chem Phys 2021 Feb 1;23(5):3637-3645. Epub 2021 Feb 1.

Institute for Computational Materials Science, School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng 475004, China.

Due to their broken out-of-plane inversion symmetry, Janus two-dimensional (2D) materials exhibit some exceptional and interesting physical properties and have recently attracted increasing attention. Herein, based on first-principles calculations, we propose a series of Janus 2D titanium nitride halide TiNXY (X, Y = F, Cl, or Br, and X ≠ Y) monolayers constructed from 2D ternary compounds TiNX (X = F, Cl, or Br), where the halogen atoms X or Y are located on each side of the monolayer, respectively. Our calculations confirm that the Janus monolayers are both dynamically and thermally stable. As compared with those of perfect TiNX monolayers, the band-structure changes of Janus TiNXY monolayers are very limited and the corresponding bandgaps only increase by about 0.1-0.2 eV. Meanwhile, the Janus TiNXY monolayers show remarkable out-of-plane piezoelectricity by virtue of their broken centrosymmetry. The calculated out-of-plane piezoelectric coefficient d is as high as 0.34 pm V, which is larger than those of most 2D piezoelectric materials reported previously. In addition, it is found that the formation of Janus structures could effectively improve the carrier mobility. The hole mobilities along the x-direction (y-direction) of Janus TiNFCl and TiNFBr monolayers reach as high as 5402 (5118) and 5538 (4135) cm V s at 300 K, respectively, which is almost twice as large as those of perfect TiNX monolayers. The giant out-of-plane piezoelectricity and high carrier mobility of Janus TiNXY monolayers suggest that these novel 2D materials could be promising for applications in electronic and piezoelectric devices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0cp06116fDOI Listing
February 2021

Hock-a-loogie saliva as a diagnostic specimen for SARS-CoV-2 by a PCR-based assay: A diagnostic validity study.

Clin Chim Acta 2020 Dec 15;511:177-180. Epub 2020 Oct 15.

Department of Laboratory Medicine, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, PR China; Key Laboratory of Clinical In Vitro Diagnostic Techniques of Zhejiang Province, Hangzhou, PR China; Institute of Laboratory Medicine, Zhejiang University, Hangzhou, PR China; State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, PR China. Electronic address:

To clarify the effect of different respiratory sample types on SARS-CoV-2 detection, we collected throat swabs, nasal swabs and hock-a-loogie saliva or sputum, and compared their detection rates and viral loads. The detection rates of sputum (95.65%, 22/23) and hock-a-loogie saliva (88.09%, 37/42) were significantly higher than those in throat swabs (41.54%, 27/65) and nasal swabs (72.31%, 47/65) (P < 0.001). The Ct Values of sputum, hock-a-loogie saliva and nasal swabs were significantly higher than that in throat swabs, whereas no significant difference was observed between sputum and saliva samples. Hock-a-loogie saliva are reliable sample types that can be used to detect SARS-CoV-2, and worthy of clinical promotion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cca.2020.10.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7557199PMC
December 2020

Viral load dynamics and disease severity in patients infected with SARS-CoV-2 in Zhejiang province, China, January-March 2020: retrospective cohort study.

BMJ 2020 04 21;369:m1443. Epub 2020 Apr 21.

State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Centre for Infectious Diseases, Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.

Objective: To evaluate viral loads at different stages of disease progression in patients infected with the 2019 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the first four months of the epidemic in Zhejiang province, China.

Design: Retrospective cohort study.

Setting: A designated hospital for patients with covid-19 in Zhejiang province, China.

Participants: 96 consecutively admitted patients with laboratory confirmed SARS-CoV-2 infection: 22 with mild disease and 74 with severe disease. Data were collected from 19 January 2020 to 20 March 2020.

Main Outcome Measures: Ribonucleic acid (RNA) viral load measured in respiratory, stool, serum, and urine samples. Cycle threshold values, a measure of nucleic acid concentration, were plotted onto the standard curve constructed on the basis of the standard product. Epidemiological, clinical, and laboratory characteristics and treatment and outcomes data were obtained through data collection forms from electronic medical records, and the relation between clinical data and disease severity was analysed.

Results: 3497 respiratory, stool, serum, and urine samples were collected from patients after admission and evaluated for SARS-CoV-2 RNA viral load. Infection was confirmed in all patients by testing sputum and saliva samples. RNA was detected in the stool of 55 (59%) patients and in the serum of 39 (41%) patients. The urine sample from one patient was positive for SARS-CoV-2. The median duration of virus in stool (22 days, interquartile range 17-31 days) was significantly longer than in respiratory (18 days, 13-29 days; P=0.02) and serum samples (16 days, 11-21 days; P<0.001). The median duration of virus in the respiratory samples of patients with severe disease (21 days, 14-30 days) was significantly longer than in patients with mild disease (14 days, 10-21 days; P=0.04). In the mild group, the viral loads peaked in respiratory samples in the second week from disease onset, whereas viral load continued to be high during the third week in the severe group. Virus duration was longer in patients older than 60 years and in male patients.

Conclusion: The duration of SARS-CoV-2 is significantly longer in stool samples than in respiratory and serum samples, highlighting the need to strengthen the management of stool samples in the prevention and control of the epidemic, and the virus persists longer with higher load and peaks later in the respiratory tissue of patients with severe disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bmj.m1443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7190077PMC
April 2020

InTeI: a novel wide-bandgap 2D material with desirable stability and highly anisotropic carrier mobility.

Nanoscale 2020 Mar 27;12(10):5888-5897. Epub 2020 Feb 27.

Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 475004, China.

Recently, stable 2D wide-bandgap semiconductors with excellent electronic and photoelectronic properties have attracted much scientific and technological interest. In this study, we predict a novel InTeI monolayer which has a wide bandgap of 2.735 eV and a anisotropic electron mobility as high as 12 137.80 cm V s based on first-principles calculations. With an exfoliating energy lower than that of monolayer phosphorene, it is feasible to synthesize the 2D InTeI monolayer through mechanical exfoliation from their 3D bulk crystals. Remarkably, the monolayer InTeI achieves the indirect-to-direct bandgap transition under a small in-plane uniaxial strain, while a quasi-direct bandgap can be achieved in the InTeI nanosheets with elevated thickness. The InTeI monolayer and nanosheets have suitable band alignments in the visible-light excitation region. In addition, our theoretical simulations determine that 2D InTeI materials exhibit more excellent oxidation resistance than black phosphorene. The results not only identify a novel class of 2D wide-bandgap semiconductors but also demonstrate their potential applications in nanoelectronics and optoelectronics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9nr10619gDOI Listing
March 2020

Decreased Frequencies of Th17 and Tc17 Cells in Patients Infected with Avian Influenza A (H7N9) Virus.

J Immunol Res 2019 2;2019:1418251. Epub 2019 Apr 2.

Center of Clinical Laboratory, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, China.

The outbreak of avian influenza A (H7N9) virus infection, with a high mortality rate, has caused concern worldwide. Although interleukin-17- (IL-17-) secreting CD4 T (Th17) and CD8 T (Tc17) cells have been proven to play crucial roles in influenza virus infection, the changes and roles of Th17 and Tc17 cells in immune responses to H7N9 infection remain controversial. In this study, we found that the frequencies of Th17 and Tc17 cells among human peripheral blood mononuclear cells (PBMCs) as well as IL-17A protein and mRNA levels were markedly decreased in patients with acute H7N9 virus infection. A positive correlation was found between the serum IL-17A level and the frequency of these two cell groups. infection experiments revealed decreased Th17 and Tc17 cell frequency and IL-17A levels at various time points postinfection. In addition, Th17 cells were the predominant sources of IL-17A in PBMCs of patients infected with H7N9 virus. Taken together, our results indicate immune disorder in acute H7N9 infection and a restored Th17 and Tc17 cell frequency might serve as a biomarker for predicting recovery in patients infected with this virus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2019/1418251DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6466882PMC
August 2019

PVT1 affects EMT and cell proliferation and migration via regulating p21 in triple-negative breast cancer cells cultured with mature adipogenic medium.

Acta Biochim Biophys Sin (Shanghai) 2018 Dec;50(12):1211-1218

Medical Research Institute, Wuhan University, Wuhan, China.

Excessive adiposity has long been proved to be associated with greater incidence and mortality of breast cancer in post-menopausal women. However, the effects and underlying mechanisms of human adipocytes on breast cancer cells remain largely unknown. In recent years, several reports have revealed the oncogenic role of long non-coding RNA PVT1 in breast cancer. Here, we aimed to investigate the role and underlying mechanisms of PVT1 in triple-negative breast cancer (TNBC) cells cultured with mature adipogenic medium. At first, we successfully induced adipogenic differentiation from human adipose-derived mesenchymal stem cells and collected the mature adipogenic medium to mimic excessive adiposity. Our results demonstrated that the mature adipogenic medium promoted the epithelial-mesenchymal transition, enhanced the cell viability and migration potential of TNBC cells. In addition, we proved that mature adipogenic medium affected the PVT1 expression and inhibition of the PVT1 disturbed the role of mature adipogenic medium in TNBC cells. Finally, we illustrated that repression of p21 restored the phenotype caused by PVT1 knockdown in TNBC cells treated with mature adipogenic medium. Taken together, our results demonstrated that PVT1 affected the role of mature adipogenic medium in TNBC cells via modulating p21 expression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/abbs/gmy129DOI Listing
December 2018

Peptide LL-37 coating on micro-structured titanium implants to facilitate bone formation in vivo via mesenchymal stem cell recruitment.

Acta Biomater 2018 10 25;80:412-424. Epub 2018 Sep 25.

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China. Electronic address:

Titanium (Ti) and Ti-alloys were widely used in clinic orthopedics, however, the insufficient bone formation surrounding Ti-based implants still limited their biological performances. Surface modification of Ti substrates is essential to improve their interactions with bone-forming cells and bone tissue. In this study, we modified Ti substrates by coating peptide LL-37 onto micro-structured Ti substrates and aimed to (i) induce mesenchymal stem cells (MSCs) migration both in vitro and in vivo, (ii) facilitate osteogenic differentiation of MSCs and new bone formation. The surface micro-structured Ti substrates with hydroxyapatite deposition were fabricated by a two-step method including micro-arc oxidation (MAO) and hydrothermal treatment. LL-37 was loaded on micro-structured Ti substrates with the assistance of polydopamine coating. We confirmed that surface-modified Ti substrates benefited viability, adhesion, migration and osteogenic differentiation of MSCs in vitro. In a femur-defect rat model, the surface-modified Ti implants effectively induced CD29/CD90 positive cells migration in one week after implantation. According to the results of H&E, Masson's trichrome staining and immunohistochemical staining of OCN, OPN and collagen I, the targeted Ti implants exhibited significant new bone formation after implantation for 4 weeks. These results indicate that the surface modification of Ti samples facilitated bone formation through MSCs recruitment. STATEMENT OF SIGNIFICANCE: The inherent surface bioinertness of titanium (Ti) and Ti-alloys still limits their biological performances in clinical applications. Recently, the strategy of mesenchymal stem cells (MSCs) recruitment has been proposed to improve the osteointegration of bone implants. Herein, we reports the surface modification of Ti implants from the point of MSCs recruitment. Peptide LL-37 was coated on micro-structured Ti substrates to (i) recruit MSCs, (ii) regulate bio-physiological performance of MSCs, and (iii) facilitate bone formation in vivo. Our results improve the understanding of the interaction between Ti implants and MSCs, and provide a promising strategy of MSCs recruitment in the design of bone repair related biomaterials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actbio.2018.09.036DOI Listing
October 2018

LncRNA-HOTAIR inhibition aggravates oxidative stress-induced H9c2 cells injury through suppression of MMP2 by miR-125.

Acta Biochim Biophys Sin (Shanghai) 2018 Oct;50(10):996-1006

Medical Research Institute, Wuhan University, Wuhan, China.

Acute myocardial infarction (AMI) is one of the major causes of morbidity and mortality in the world. Ischemia/reperfusion (I/R) injury-induced cardiomyocytes death is the main obstacle that limits the heart function recovery of the AMI patients. Reactive oxygen species (ROS) generated by mitochondria is the main pathological stimulus of cardiomyocytes death during heart I/R injury process. Hence, to understand the underlying mechanism of cardioymocytes proliferation and apoptosis under oxidative stress is crucial for effective AMI therapy. In this study, we found that the expression of long non-coding RNA HOTAIR was significantly downregulated in H9c2 cells in response to oxidative stimuli. HOTAIR knockdown further attenuated H9c2 cells proliferation and accelerated H9c2 cells apoptosis in oxidative stress, while HOTAIR overexpression can protect H9c2 cells from oxidative stress-induced injury. Additionally, HOTAIR acted as a sponge for miR-125. MiR-125 inhibitors restored the H9c2 cells proliferation and migration potential after HOTAIR knockdown in oxidative stress. Meanwhile, MMP2 was identified as a target of miR-125. MMP2 knockdown blocked miR-125 inhibitors' protect effect on H9c2 cells in oxidative stress. Further study demonstrated that HOTAIR inhibition can aggravate oxidative stress-induced H9c2 cells injury through HOTAIR/miR-125/MMP2 axis. Our finding revealed a novel regulatory mechanism for cardiomyocytes proliferation and apoptosis under oxidative stress conditions, which provided a therapeutic approach for myocardium repair after AMI injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/abbs/gmy102DOI Listing
October 2018

Polydopamine-Assisted Hydroxyapatite and Lactoferrin Multilayer on Titanium for Regulating Bone Balance and Enhancing Antibacterial Property.

ACS Biomater Sci Eng 2018 Sep 27;4(9):3211-3223. Epub 2018 Aug 27.

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, P. R. China.

Maintaining the balance between bone formation and bone resorption as well as reducing bacterial infection are two major challenges for titanium (Ti) when it is used as the implant in orthopedic surgery. Because of its excellent properties, including anti-inflammatory, antimicrobial, promoting osteoblasts, and inhibiting osteoclasts growth, lactoferrin (LF) is a potential bioactive molecule for surface modification of Ti implants. Inspired by the highly hierarchical structure of natural bone tissue, in this work, a polydopamine-assisted hydroxyapatite and lactoferrin multilayer structure (PDA-HA-LF) was prepared onto the Ti substrate surface by a biomimetic approach and spin-assisted layer-by-layer (LBL) assembly technique. Meanwhile, its capabilities on regulation of bone balance and antibacterial properties were measured with cell experiments and antimicrobial activity in vitro. Furthermore, the regulation theory was investigated by qPCR and theoretical simulation. The results showed that the biological properties of LF are highly correlated with its concentration. High concentration of LF was toxic to osteoblasts but has obvious effects on inhibition of osteoclasts and bacteria ( and ). However, through polydopamine-assisted hydroxyapatite deposition, cytotoxicity of LF could be improved. The modified Ti implant could greatly improve the proliferation and differentiation of osteoblasts. Meanwhile, the activity of osteoclasts was somewhat inhibited, which indicated that the modified Ti implant could efficiently regulate the balance between bone resorption and bone formation, as well as have a certain antibacterial effect.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsbiomaterials.8b00791DOI Listing
September 2018

Deferoxamine loaded titania nanotubes substrates regulate osteogenic and angiogenic differentiation of MSCs via activation of HIF-1α signaling.

Mater Sci Eng C Mater Biol Appl 2018 Oct 3;91:44-54. Epub 2018 May 3.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University, Chongqing 400044, China; Chongqing Collaborative Innovation Center for Minimally-invasive and Noninvasive Medicine, Chongqing 400016, China. Electronic address:

To develop biomaterials for inducing osteogenic and angiogenic differentiation of mesenchymal stem cells (MSCs) is crucial for bone repair. In this study, we employed titania nanotubes (TNT) as drug nanoreservoirs to load deferoxamine (DFO), and then deposited chitosan (Chi) and gelatin (Gel) multilayer as coverage structure via layer-by-layer (LBL) assembly technique, resulting in TNT-DFO-LBL substrates. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements were employed to characterize the physical and chemical properties of the substrates. The results proved the successful fabrication of multilayer coating on TNT array. DFO released from the TNT arrays in a sustained manner. The drug-device combination titanium (Ti) substrates positively improved the adhesion, proliferation, osteogenic/angiogenic differentiation of MSCs and mediated the growth behavior of human umbilical vein endothelial cells (HUVECs). Moreover, the TNT-DFO-LBL substrates up-regulated osteogenic and angiogenic differentiation related genes expression of MSCs by activating HIF-1α signaling pathway. The approach presents here has a potential impact on the development of high quality Ti-based orthopedic implants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.msec.2018.04.098DOI Listing
October 2018

Multilayered coating of titanium implants promotes coupled osteogenesis and angiogenesis in vitro and in vivo.

Acta Biomater 2018 07 25;74:489-504. Epub 2018 Apr 25.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University, Chongqing 400044, China; Chongqing Collaborative Innovation Center for Minimally-Invasive and Noninvasive Medicine, Chongqing 400016, China. Electronic address:

We used surface-modified titanium (Ti) substrates with a multilayered structure composed of chitosan-catechol (Chi-C), gelatin (Gel) and hydroxyapatite (HA) nanofibers, which were previously shown to improve osteogenesis, as a platform to investigate the interaction of osteogenesis and angiogenesis during bone healing. Combined techniques of Transwell co-culture, wound healing assay, enzyme linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), western blotting and immunohistochemical staining were used to evaluate adhesion, morphology and migration of adipose-derived mesenchymal stem cells (Ad-MSCs) and human umbilical vein endothelial cells (HUVECs) grown on different Ti substrates. We investigated the effect of substrates on the osteogenic differentiation of Ad-MSCs and reciprocal paracrine effects of Ad-MSCs on HUVECs or vice versa. The multilayered Ti substrates directly regulated the cellular functions of Ad-MSCs and angiogenic HUVECs and mediated communication between them by enhancing paracrine effects via cell-matrix interactions in vitro. The in vivo results showed that the change of microenvironment induced by surface-modified Ti implants promoted the adhesion, recruitment and proliferation of MSCs and facilitated coupled osteogenesis and angiogenesis in bone healing. The study proved that multilayer-film-coated Ti substrates positively mediated cellular biological function in vitro and improved bone healing in vivo.

Statement Of Significance: Recent studies have revealed that osteogenesis and angiogenesis are coupled, and that communication between osteoblasts and endothelial cells is essential for bone healing and remodeling processes; however, these conclusions only result from in vitro studies or in vivo studies using transgenic murine models. Relatively little is known about the communication between osteoblasts and endothelial cells in peri-implants during bone healing processes. Our results revealed the cellular/molecular mechanism of how multilayered Ti substrates mediate reciprocal paracrine effects between adipose-derived mesenchymal stem cells and human umbilical vein endothelial cells; moreover, the interactions between the cell-matrix and peri-implant was proven in vivo with enhanced bone healing. This study contributes to our understanding of the fundamental mechanisms of angiogenesis and osteogenesis that affect peri-implantation, and thus, provides new insights into the design of future high-quality orthopedic implants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actbio.2018.04.043DOI Listing
July 2018

Functionalizing titanium surface with PAMAM dendrimer and human BMP2 gene via layer-by-layer assembly for enhanced osteogenesis.

J Biomed Mater Res A 2018 03 15;106(3):706-717. Epub 2017 Nov 15.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University, Chongqing, 400044, China.

The study reports on the gene functionalization of titanium substrates with multilayered functional human BMP2 (hBMP2) gene plasmid and its effects on osteogenesis in vitro and in vivo. The multilayers comprising cationic poly(amidoamine) (PAMAM) dendrimer/EGFP-hBMP2 plasmid DNA complex (d-DNA) and anionic naked plasmid were deposited on titanium substrates via layer-by-layer (LbL) assembly technique, which was revealed by atomic force microscopy (AFM), water contact angle measurement, and release profiles. The expression of marker gene EGFP and functional gene hBMP2 were observed in osteoblasts. The assays of alkaline phosphatase activity, collagen secretion, ECM mineralization, and osteogenesis-related genes expression indicated that the multilayered structure improved the osteogenic differentiation in vitro. Moreover, the femur and subcutaneous transplantation of multilayered titanium implants were also investigated to reveal osteogenesis peri-implant by using histological examination and X-ray imaging. The in vivo histologic results showed that the BMP2 group (containing functional gene hBMP2) resulted in improved osteogenic proteins expression in subcutaneous and femur tissue, as well as high level of bone formation and % bone-implant contact (%BIC) peri-implant. The study offers an effective dendrimer and hBMP2 based strategy for surface functionalization of titanium implants in potential orthopedic applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 706-717, 2018.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbm.a.36273DOI Listing
March 2018

Strontium folic acid derivative functionalized titanium surfaces for enhanced osteogenic differentiation of mesenchymal stem cells in vitro and bone formation in vivo.

J Mater Chem B 2017 Sep 3;5(33):6811-6826. Epub 2017 Aug 3.

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, P. R. China.

The introduction of the bioactive strontium (Sr) element has become an attractive method in the design of bio-functional layers on titanium surfaces. However, there are still no effective solutions to some of the associated problems including the toxicity of free Sr ions and the rapid and irreversible loss of the strontium element from the bio-functional layers. In this study, we successfully fabricated a bioactive layer on Ti substrates with a strontium folic acid derivative (FASr). About 3.11 at% Sr was incorporated into the Ti surface. The characterization results showed that FASr was stable over a long period of time and minimal free Sr ions were detected in simulated body fluid (SBF). In the in vitro experiment, the FASr could significantly promote the cell adhesion, proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) over a short period. Furthermore, it could dramatically accelerate the bone formation around the implant. In vivo, a total of 30 7-week old male Sprague Dawley (SD) rats were applied for implantation tests. The results showed that this positive stimulatory effect became more evident in the later stages of the in vivo observation. This study provides an effective strategy for designing and optimizing Ti-based implants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c7tb01529aDOI Listing
September 2017

Phenylboronic acid-modified hollow silica nanoparticles for dual-responsive delivery of doxorubicin for targeted tumor therapy.

Regen Biomater 2017 Mar 11;4(2):111-124. Epub 2017 Jan 11.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University, Chongqing 400044, P. R. China.

This work reports a multifunctional nanocarrier based on hollow mesoporous silica nanoparticles (HMSNs) for targeting tumor therapy. Doxorubicin (DOX) was loaded into HMSNs and blocked with cytochrome C conjugated lactobionic acid (CytC-LA) via redox-cleavable disulfide bonds and pH-disassociation boronate ester bonds as intermediate linkers. The CytC-LA was used both as sealing agent and targeting motif. A series of characterizations demonstrated the successful construction of the drug delivery system. The system demonstrated pH and redox dual-responsive drug release behavior . The DOX loading HMSNs system displayed a good biocompatibility, which could be specifically endocytosed by HepG2 cells and led to high cytotoxicity against tumor cells by inducing cell apoptosis. data (tumor volume, tumor weight, terminal deoxynucleotidyl transferase dUTP nick end labeling and hematoxylin and eosin staining) proved that the system could deliver DOX to tumor site with high efficiency and inhibit tumor growth with minimal toxic side effect.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/rb/rbw045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6371689PMC
March 2017

Surface functionalization of titanium implants with chitosan-catechol conjugate for suppression of ROS-induced cells damage and improvement of osteogenesis.

Biomaterials 2017 01 2;114:82-96. Epub 2016 Nov 2.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University, Chongqing 400044, PR China. Electronic address:

Oxidative stress induced by reactive oxygen species (ROS) overproduction would hinder bone healing process at the interface of bone/implant, yet underlying mechanism remains to be explored. To endow titanium (Ti) substrates with antioxidant activity for enhanced bone formation, multilayered structure composing of chitosan-catechol (Chi-C), gelatin (Gel) and hydroxyapatite (HA) nanofibers was constructed on Ti substrates. Surface wettability and topography of multilayer coated Ti substrates were characterized by water contact angle measurement, scanning electron microscopy and atomic force microscopy, respectively. Chi-C containing multilayer on Ti surface effectively protected osteoblasts from ROS damage, which was revealed by high level of intracellular ROS scavenging activity and reduced oxidative damage on cellular level by regulating the expression of cell adhesion related genes (integrin αv, β3, CDH11 and CDH2). Moreover, it regulated the production of cell adhesive and anti-apoptotic related proteins (p-MYPT1, p-FAK, p-Akt and Bcl-2) and pro-apoptotic critical executioners (Bax and cleaved caspase 3). Beside, the composite multilayer of Chi-C/Gel/HA nanofibers on Ti substrates promoted osteoblasts differentiation, which was evidenced by high expression levels of alkaline phosphatase activity, collagen secretion, ECM mineralization and osteogenesis-related genes expression in vitro. The in vivo experiments of μ-CT analysis, push out test and histochemistry staining further confirmed that Chi-C multilayered implant had great potential for improved early bone healing. Overall, the study offers an effective strategy for the exploration of high quality Ti implants for orthopedic applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biomaterials.2016.10.055DOI Listing
January 2017

Human Serum-Specific Activation of Alternative Sigma Factors, the Stress Responders in Aggregatibacter actinomycetemcomitans.

PLoS One 2016 4;11(8):e0160018. Epub 2016 Aug 4.

Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, United States of America.

Aggregatibacter actinomycetemcomitans, a known pathogen causing periodontal disease and infective endocarditis, is a survivor in the periodontal pocket and blood stream; both environments contain serum as a nutrient source. To screen for unknown virulence factors associated with this microorganism, A. actinomycetemcomitans was grown in serum-based media to simulate its in vivo environment. Different strains of A. actinomycetemcomitans showed distinct growth phenotypes only in the presence of human serum, and they were grouped into high- and low-responder groups. High-responders comprised mainly serotype c strains, and showed an unusual growth phenomenon, featuring a second, rapid increase in turbidity after 9-h incubation that reached a final optical density 2- to 7-fold higher than low-responders. Upon further investigation, the second increase in turbidity was not caused by cell multiplication, but by cell death. Whole transcriptomic analysis via RNA-seq identified 35 genes that were up-regulated by human serum, but not horse serum, in high-responders but not in low-responders, including prominently an alternative sigma factor rpoE (σE). A lacZ reporter construct driven by the 132-bp rpoE promoter sequence of A. actinomycetemcomitans responded dramatically to human serum within 90 min of incubation only when the construct was carried by a high responder strain. The rpoE promoter is 100% identical among high- and low-responder strains. Proteomic investigation showed potential interactions between human serum protein, e.g. apolipoprotein A1 (ApoA1) and A. actinomycetemcomitans. The data clearly indicated a different activation process for rpoE in high- versus low-responder strains. This differential human serum-specific activation of rpoE, a putative extra-cytoplasmic stress responder and global regulator, suggests distinct in vivo adaptations among different strains of A. actinomycetemcomitans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160018PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4973924PMC
August 2017

Photosensitizer enhanced disassembly of amphiphilic micelle for ROS-response targeted tumor therapy in vivo.

Biomaterials 2016 10 5;104:1-17. Epub 2016 Jul 5.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University, Chongqing 400044, PR China. Electronic address:

This study reports a reactive oxygen species (ROS) sensitive drug delivery system based on amphiphilic polymer of poly(propylene sulfide)-polyethylene glycol-serine-folic acid (PPS-mPEG-Ser-FA). The polymer could form homogeneous micelles with an average diameter of around 80 nm through self-assembly, which would then be loaded with the singlet oxygen-generating photosensitizer of zinc phthalocyanine (ZNPC) and anti-cancer drug of DOX. The disassembly of micelles could be triggered by the hydrophobic to hydrophilic transition of the PPS core in response to ROS-induced oxidation in vitro. ZNPC molecules are capable of producing ROS under laser irradiation, which results in the rapid disassembly of micelles and releasing of the anti-tumor drug for tumor therapy under physiological condition otherwise. Moreover, the excessive ROS production deriving from ZNPC synergically induces cells apoptosis. Furthermore, the DOX loaded amphiphilic micelles could be internalized by tumor cells via FA receptor-mediated endocytosis to effectively inhibit the tumor growth in vivo, while with only minimal toxic side effects. The results in vitro and in vivo consistently demonstrate that the light-responsive micelle is a promising biodegradable nanocarrier for on-command drug release and targeted tumor therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biomaterials.2016.07.002DOI Listing
October 2016

Influence of strontium ions incorporated into nanosheet-pore topographical titanium substrates on osteogenic differentiation of mesenchymal stem cells in vitro and on osseointegration in vivo.

J Mater Chem B 2016 Jul 15;4(26):4549-4564. Epub 2016 Jun 15.

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, P. R. China.

Biophysical cues or biochemical cues were proved to efficiently regulate the fate of mesenchymal stem cells (MSCs), but their synergistic effects on the biological functions of MSCs remain to be further investigated. In this study, titanium (Ti) substrates were fabricated with distinct sub-micrometer nanosheet-pore topography via a vapor alkaline treatment method. Strontium (Sr) ions were then incorporated into the Ti substrates via ion exchange. Apart from the influence of biophysical cues from topography, MSCs were simultaneously affected by the biochemical cues from the continuously released Sr ions. The MSCs grown onto Ti substrates with Sr incorporated in them displayed higher (p < 0.05 or p < 0.01) cellular functions than those of pure Ti substrates, including proliferation, the genes and proteins expressions of osteogenic markers and mineralization potential when comparing them with the results of those MSCs grown onto pure Ti substrates. Furthermore, the in vivo investigations demonstrated that the Sr incorporated Ti implants promoted new bone formation. All the results indicated that the incorporated Sr ions and the nanosheet-pore topography of the Ti substrates synergistically enhanced the osteogenic differentiation of MSCs in vitro and osseointegration in vivo. This study advances the understanding of the synergistic influence of biophysical cues and biochemical cues on MSC osteogenic differentiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c6tb00724dDOI Listing
July 2016

Nanosheet-pore topographical titanium substrates: a biophysical regulator of the fate of mesenchymal stem cells.

J Mater Chem B 2016 Mar 16;4(10):1797-1810. Epub 2016 Feb 16.

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, P. R. China.

Recent reports have demonstrated that nano- or micro-scale topography could enhance the cellular functions of stem cells. In this study, a sub-micrometer topography composed of nanosheet-pore structures was fabricated on the pure titanium surface by a simple vapor alkaline-treatment method to understand more profoundly sub-micrometer topography mediated stem cell behaviors. The topography was characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and contact angle measurements, respectively. It specifically mediated cellular functions of rat bone marrow-derived mesenchymal stem cells (MSCs) on cellular and molecular levels under either normal medium or osteoinductive medium conditions. The experimental results indicated that the topography dramatically promoted the adhesion of MSCs grown on the surface, but the shape, morphology and spreading of cells were not significantly affected. In addition, the study demonstrated that the formation of focal adhesion complexes (FAs) were highly dependent on the topography, which in turn affects the subsequent biological functions of MSCs, especially accelerating osteogenic differentiation of MSCs under different conditions. Overall, the sub-micrometer topographical titanium substrate was an excellent biophysical regulator of the fate of mesenchymal stem cells, specifically inducing their differentiation into osteoblasts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c5tb02391bDOI Listing
March 2016

Alendronate-loaded hydroxyapatite-TiO nanotubes for improved bone formation in osteoporotic rabbits.

J Mater Chem B 2016 Feb 1;4(8):1423-1436. Epub 2016 Feb 1.

Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, P. R. China.

Early mechanical fixation between an implant and native bone is critically important for successful orthopedic implantation, especially for hosts suffering osteoporosis with reduced bone mass. To endow a titanium-based implant with a desirable local anti-osteoporosis property for enhancing its early osseointegration, alendronate-loaded hydroxyapatite-TiO nanotube (TNT-HA-Aln) substrates were fabricated and systematically characterized in this study. The results of Aln/Ca release and Ca concentration in an osteoclast medium verified that the release of Aln was significantly accelerated along with the acidity rise caused by osteoclast differentiation. Other in vitro tests, such as CCK-8, alkaline phosphatase (ALP), mineralization, gene expression (Runx2, Osterix, ALP, Col I, OPN, OC, OPG and RANKL), protein production (OPG and RANKL) and tartrate-resistant acid phosphatase (TRAP), proved that TNT-HA-Aln substrates have great potential for improving osteoblast proliferation/differentiation and inhibiting osteoclast differentiation. Moreover, in vivo tests, such as the push-out test, micro-CT and H&E staining proved that TNT-HA-Aln implants could efficiently improve local osseointegration after implantation for 3 months. The study provides an alternative to exploiting drug-device combinations to enhance early osseointegration in osteoporosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c5tb01956gDOI Listing
February 2016

Regulation of the biological functions of osteoblasts and bone formation by Zn-incorporated coating on microrough titanium.

ACS Appl Mater Interfaces 2014 Sep 29;6(18):16426-40. Epub 2014 Aug 29.

Key Laboratory of Biorheological Science and Technology, Ministry of Education College of Bioengineering, Chongqing University , Chongqing 400044, P. R. China.

To improve the biological performance of titanium implant, a series of Zn-incorporated coatings were fabricated on the microrough titanium (Micro-Ti) via sol-gel method by spin-coating technique. The successful fabrication of the coating was verified by combined techniques of scanning electron microscopy, surface profiler, X-ray diffraction, X-ray photoelectron spectroscopy, and water contact angle measurements. The incorporated zinc existed as ZnO, which released Zn ions in a sustained manner. The Zn-incorporated samples (Ti-Zn0.08, Ti-Zn0.16, and Ti-Zn0.24) efficiently inhibited the adhesion of both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria. The in vitro evaluations including cell activity, alkaline phosphatase (ALP), mineralization, osteogenic genes expressions (Runx2, ALP, OPG, Col I, OPN, and OC), and tartrate-resistant acid phosphatase, confirmed that Ti-Zn0.16 sample was the optimal one to regulate the proliferation or differentiation for both osteoblasts and osteoclasts. More importantly, in vivo evaluations including Micro-CT analysis, push-out test, and histological observations verified that Ti-Zn0.16 implants could efficiently promote new bone formation after implantation for 4 and 12 weeks, respectively. The resulting material thus has potential application in orthopedic field.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/am5049338DOI Listing
September 2014

[Preparation and bio-evaluation of tissue engineered scaffold based on decellularized whole heart extracellular matrix].

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2013 Aug;27(8):945-9

Chinese PLA General Hospital & Medical School of Chinese PLA, Beijing, 100853, P R China.

Objective: To investigate a method for preparing decellularized rat heart scaffold, and to detect and evaluate the decellularized scaffold.

Methods: The decellularized rat heart scaffold was prepared by retrograde perfusion with a combination of enzymatic and Triton X-100 detergent methods to remove the populations of resident cells, and then the decellularized scaffold was observed by gross, toluidine blue staining, HE staining, scanning electron microcope (SEM), Alcian blue staining, and immunohistochemisty staining to evaluate the structure and essential component of extracellular maxtix (ECM) in the scaffold.

Results: Tissue engineered scaffold based on decellularized whole heart ECM was successfully prepared, which maintained not only the gross morphology of the heart, but also the intact vascular structure and ultrastructural conformation that certified by toluidine blue staining, HE staining, and SEM analyses. Alcian blue staining and immunohistochemisty staining showed that the essential components of ECM, such as collagen type I, glycosaminoglycan, fibronectin, and Laminin were remained in decellularized whole heart matrix.

Conclusion: The decellularized whole heart ECM prepared by method mentioned can maintain the intact structure of rat heart and basic compositions of extracellular matrices, so it could be suitable for further studies of tissue engineered scaffolds for whole heart reconstruction.
View Article and Find Full Text PDF

Download full-text PDF

Source
August 2013
-->