Publications by authors named "Iulian Antoniac"

39 Publications

Treatment of Knee Osteochondral Fractures.

Healthcare (Basel) 2022 Jun 8;10(6). Epub 2022 Jun 8.

Department of Morphological Sciences, Carol Davila University of Medicine and Pharmacy, RO-020021 Bucharest, Romania.

Osteochondral lesions (OCLs) that are frequently encountered in skeletally immature and adult patients are more common than once thought, and their incidence rate is rising. These lesions can appear in many synovial joints of the body, such as the shoulder, elbow, hip, and ankle, occurring most often in the knee. The term osteochondral lesion includes a vast spectrum of pathologies such as osteochondritis dissecans, osteochondral defects, osteochondral fractures, and osteonecrosis of the subchondral bone. When considering this, the term osteochondral fracture is preserved only for an osteochondral defect that combines disruption of the articular cartilage and subchondral bone. These fractures commonly occur after sports practice and are associated with acute lateral patellar dislocations. Many of these lesions are initially diagnosed by plain radiographs; however, a computed tomography (CT) scan or magnetic resonance imaging (MRI) can add significant value to the diagnosis and treatment. Treatment methods may vary depending on the location and size of the fracture, fragment instability, and skeletal maturity. The paper reports a 14-year-old boy case with an osteochondral fracture due to sports trauma. The medical approach involved an arthrotomy of the knee, drainage of the hematoma, two Kirschner wires (K-wires) for temporary fixation to restructure anatomic alignment, and a titanium Herbert screw fixing the fracture permanently. The patient had a favorable postoperative outcome with no residual pain, adequate knee stability, and a normal range of motion. The mobility of the knee was fully recovered.
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http://dx.doi.org/10.3390/healthcare10061061DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9222836PMC
June 2022

Electrochemical and In Vitro Biological Evaluation of Bio-Active Coatings Deposited by Magnetron Sputtering onto Biocompatible Mg-0.8Ca Alloy.

Materials (Basel) 2022 Apr 25;15(9). Epub 2022 Apr 25.

Department of Orthopedics and Traumatology, University of Medicine and Pharmacy Gr.T.Popa Iasi, 16 University Str., 700115 Iasi, Romania.

The use of resorbable magnesium alloys in the design of implants represents a new direction in the healthcare domain. Two main research avenues are currently explored for developing or improving metallic biomaterials: (i) increase of their corrosion resistance by designed compositional and structural modifications, and (ii) functionalization of their surfaces by coating with ceramic or polymeric layers. The main objective of this work was to comparatively assess bio-functional coatings (i.e., highly-crystallized hydroxyapatite and silica-rich glass) deposited by radio-frequency magnetron sputtering (RF-MS) on a biodegradable Mg-0.8Ca alloy (0.8 wt.% of Ca). After probing their morphology (by scanning electron microscopy) and structure (by Fourier transform infrared spectroscopy and grazing incidence X-ray diffraction), the corrosion resistance of the RF-MS coated Mg-0.8Ca substrates was electrochemically tested (in synthetic biological media with different degrees of biomimicry), and their cytocompatibility was assessed in osteoblast and fibroblast cell cultures. By collective assessment, the most promising performances, in terms of mass loss (~7% after 12 days), hydrogen release rate (~6 mL/cm after 12 days), electrochemical corrosion parameters and cytocompatibility, were obtained for the crystalline HA coating.
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http://dx.doi.org/10.3390/ma15093100DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102359PMC
April 2022

Bone Cements Used for Hip Prosthesis Fixation: The Influence of the Handling Procedures on Functional Properties Observed during In Vitro Study.

Materials (Basel) 2022 Apr 19;15(9). Epub 2022 Apr 19.

Faculty of Medicine, University Lucian Blaga of Sibiu, 2A Lucian Blaga Str., 550169 Sibiu, Romania.

The failure of hip prostheses is a problem that requires further investigation and analysis. Although total hip replacement is an extremely successful operation, the number of revision surgeries needed after this procedure is expected to continue to increase due to issues with both bone cement types and cementation techniques (depending on the producer). To conduct a comparative analysis, as a surgeon prepared the bone cement and introduced it in the body, this study's team of researchers prepared three types of commercial bone cements with the samples mixed and placed them in specimens, following the timeline of the surgery. In order to evaluate the factors that influenced the chemical composition and structure of each bone cement sample under specific intraoperative conditions, analyses of the handling properties, mechanical properties, structure, and composition were carried out. The results show that poor handling can impede prosthesis-cement interface efficacy over time. Therefore, it is recommended that manual mixing be avoided as much as possible, as the manual preparation of the cement can sometimes lead to structural unevenness.
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http://dx.doi.org/10.3390/ma15092967DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9101139PMC
April 2022

Cranioplasty after Two Giant Intraosseous Angiolipomas of the Cranium: Case Report and Literature Review.

Healthcare (Basel) 2022 Mar 31;10(4). Epub 2022 Mar 31.

Faculty of Medicine and Pharmacy, University of Oradea, 10 P-ta 1 December Street, RO-410073 Oradea, Romania.

Angiolipomas are rare, benign tumors resulting from the proliferation of adipose tissue and blood vessels, most frequently encountered subcutaneously at the upper limbs and trunk level. Due to their rarity, few cases of intraosseous angiolipomas are presented in the literature. The paper reports a 50-year-old female case with intracranial hypertension syndrome, frontal and parietal headache, nausea, and vomiting symptoms increasing in intensity. A CT exam revealed two hypodense expansive intraosseous formations/lesions. The first one was located in the projection of the frontal bone and the second one was placed on the left parietal bone. After further investigations, a two-stage procedure was considered. A frontal craniotomy with excision of the intraosseous tumor was performed in the first stage. In the second stage, a left parietal craniotomy was done with excision of the intraosseous tumor combined with a cranioplasty procedure. The patient had a favorable postoperative evolution with no symptoms or neurological deficits. This is among the few reported cases of intraosseous angiolipoma located at the cranium level and the first case report of two intraosseous angiolipomas situated on the same site. The medical recommendation was a complete surgical excision of the lesion followed by cranioplasty.
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http://dx.doi.org/10.3390/healthcare10040655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9028485PMC
March 2022

Construction of a magnesium hydroxide/graphene oxide/hydroxyapatite composite coating on Mg-Ca-Zn-Ag alloy to inhibit bacterial infection and promote bone regeneration.

Bioact Mater 2022 Dec 3;18:354-367. Epub 2022 Mar 3.

National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China.

The improved corrosion resistance, osteogenic activity, and antibacterial ability are the key factors for promoting the large-scale clinical application of magnesium (Mg)-based implants. In the present study, a novel nanocomposite coating composed of inner magnesium hydroxide, middle graphene oxide, and outer hydroxyapatite (Mg(OH)/GO/HA) is constructed on the surface of Mg-0.8Ca-5Zn-1.5Ag by a combined strategy of hydrothermal treatment, electrophoretic deposition, and electrochemical deposition. The results of material characterization and electrochemical corrosion test showed that all the three coatings have high bonding strength, hydrophilicity and corrosion resistance. studies show that Mg(OH) indeed improves the antibacterial activity of the substrate. The next GO and GO/HA coating procedures both promote the osteogenic differentiation of MC3T3-E1 cells and show no harm to the antibacterial activity of Mg(OH) coating, but the latter exhibits the best promoting effect. studies demonstrate that the Mg alloy with the composite coating not only ameliorates osteolysis induced by bacterial invasion but also promotes bone regeneration under both normal and infected conditions. The current study provides a promising surface modification strategy for developing multifunctional Mg-based implants with good corrosion resistance, antibacterial ability and osteogenic activity to enlarge their biomedical applications.
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http://dx.doi.org/10.1016/j.bioactmat.2022.02.030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8965913PMC
December 2022

Biomaterials as Haemostatic Agents in Cardiovascular Surgery: Review of Current Situation and Future Trends.

Polymers (Basel) 2022 Mar 16;14(6). Epub 2022 Mar 16.

Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania.

Intraoperative haemostasis is of paramount importance in the practice of cardiovascular surgery. Over the past 70 years, topical haemostatic methods have advanced significantly and today we deal with various haemostatic agents with different properties and different mechanisms of action. The particularity of coagulation mechanisms after extracorporeal circulation, has encouraged the introduction of new types of topic agents to achieve haemostasis, where conventional methods prove their limits. These products have an important role in cardiac, as well as in vascular, surgery, mainly in major vascular procedures, like aortic dissections and aortic aneurysms. This article presents those agents used for topical application and the mechanism of haemostasis and offers general recommendations for their use in the operating room.
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http://dx.doi.org/10.3390/polym14061189DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8955858PMC
March 2022

Influence of Synthesis Conditions on Gadolinium-Substituted Tricalcium Phosphate Ceramics and Its Physicochemical, Biological, and Antibacterial Properties.

Nanomaterials (Basel) 2022 Mar 3;12(5). Epub 2022 Mar 3.

Institute of Pharmacy, Department of Analytical, Physical and Colloid Chemistry, I.M. Sechenov First Moscow State Medical University, 8 Trubetskaya Street, Build. 2, 119991 Moscow, Russia.

Gadolinium-containing calcium phosphates are promising contrast agents for various bioimaging modalities. Gadolinium-substituted tricalcium phosphate (TCP) powders with 0.51 wt% of gadolinium (0.01Gd-TCP) and 5.06 wt% of (0.1Gd-TCP) were synthesized by two methods: precipitation from aqueous solutions of salts (1) (Gd-TCP-pc) and mechano-chemical activation (2) (Gd-TCP-ma). The phase composition of the product depends on the synthesis method. The product of synthesis (1) was composed of -TCP (main phase, 96%), apatite/chlorapatite (2%), and calcium pyrophosphate (2%), after heat treatment at 900 °C. The product of synthesis (2) was represented by -TCP (main phase, 73%), apatite/chlorapatite (20%), and calcium pyrophosphate (7%), after heat treatment at 900 °C. The substitution of Ca ions by Gd in both -TCP (main phase) and apatite (admixture) phases was proved by the electron paramagnetic resonance technique. The thermal stability and specific surface area of the Gd-TCP powders synthesized by two methods were significantly different. The method of synthesis also influenced the size and morphology of the prepared Gd-TCP powders. In the case of synthesis route (1), powders with particle sizes of tens of nanometers were obtained, while in the case of synthesis (2), the particle size was hundreds of nanometers, as revealed by transmission electron microscopy. The Gd-TCP ceramics microstructure investigated by scanning electron microscopy was different depending on the synthesis route. In the case of (1), ceramics with grains of 1-50 μm, pore sizes of 1-10 µm, and a bending strength of about 30 MPa were obtained; in the case of (2), the ceramics grain size was 0.4-1.4 μm, the pore size was 2 µm, and a bending strength of about 39 MPa was prepared. The antimicrobial activity of powders was tested for four bacteria (, , , and ) and one fungus (), and there was roughly 30% of inhibition of the micro-organism's growth. The metabolic activity of the NCTC L929 cell and viability of the human dental pulp stem cell study demonstrated the absence of toxic effects for all the prepared ceramic materials doped with Gd ions, with no difference for the synthesis route.
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http://dx.doi.org/10.3390/nano12050852DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8912835PMC
March 2022

Magnesium-Based Alloys Used in Orthopedic Surgery.

Materials (Basel) 2022 Feb 2;15(3). Epub 2022 Feb 2.

Faculty of Medicine and Pharmacy, University Dunarea de Jos Galati, 35 Alexandru Ioan Cuza Street, 800010 Galati, Romania.

Magnesium (Mg)-based alloys have become an important category of materials that is attracting more and more attention due to their high potential use as orthopedic temporary implants. These alloys are a viable alternative to nondegradable metals implants in orthopedics. In this paper, a detailed overview covering alloy development and manufacturing techniques is described. Further, important attributes for Mg-based alloys involved in orthopedic implants fabrication, physiological and toxicological effects of each alloying element, mechanical properties, osteogenesis, and angiogenesis of Mg are presented. A section detailing the main biocompatible Mg-based alloys, with examples of mechanical properties, degradation behavior, and cytotoxicity tests related to in vitro experiments, is also provided. Special attention is given to animal testing, and the clinical translation is also reviewed, focusing on the main clinical cases that were conducted under human use approval.
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http://dx.doi.org/10.3390/ma15031148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8840615PMC
February 2022

Fluoride Treatment and In Vitro Corrosion Behavior of Mg-Nd-Y-Zn-Zr Alloys Type.

Materials (Basel) 2022 Jan 12;15(2). Epub 2022 Jan 12.

Faculty of Medicine, Lucian Blaga University of Sibiu, 2A Lucian Blaga Street, 550169 Sibiu, Romania.

Fluoride conversion coatings on Mg present many advantages, among which one can find the reduction of the corrosion rate under "in vivo" or "in vitro" conditions and the promotion of the calcium phosphate deposition. Moreover, the fluoride ions released from MgF do not present cytotoxic effects and inhibit the biofilm formation, and thus these treated alloys are very suitable for cardiovascular stents and biodegradable orthopedic implants. In this paper, the biodegradation behavior of four new magnesium biodegradable alloys that have been developed in the laboratory conditions, before and after surface modifications by fluoride conversion (and sandblasting) coatings, are analyzed. We performed structural and surface analysis (XRD, SEM, contact angle) before and after applying different surface treatments. Furthermore, we studied the electrochemical behavior and biodegradation of all experimental samples after immersion test performed in NaCl solution. For a better evaluation, we also used LM and SEM for evaluation of the corroded samples after immersion test. The results showed an improved corrosion resistance for HF treated alloy in the NaCl solution. The chemical composition, uniformity, thickness and stability of the layers generated on the surface of the alloys significantly influence their corrosion behavior. Our study reveals that HF treatment is a beneficial way to improve the biofunctional properties required for the studied magnesium alloys to be used as biomaterials for manufacturing the orthopedic implants.
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http://dx.doi.org/10.3390/ma15020566DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8779082PMC
January 2022

Magnetic Nanoparticles Used in Oncology.

Materials (Basel) 2021 Oct 10;14(20). Epub 2021 Oct 10.

Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, District 6, RO-060042 Bucharest, Romania.

Recently, magnetic nanoparticles (MNPs) have more and more often been used in experimental studies on cancer treatments, which have become one of the biggest challenges in medical research. The main goal of this research is to treat and to cure advanced or metastatic cancer with minimal side effects through nanotechnology. Drug delivery approaches take into account the fact that MNPs can be bonded to chemotherapeutical drugs, nucleic acids, synthetized antibodies or radionuclide substances. MNPs can be guided, and different treatment therapies can be applied, under the influence of an external magnetic field. This paper reviews the main MNPs' synthesis methods, functionalization with different materials and highlight the applications in cancer therapy. In this review, we describe cancer cell monitorization based on different types of magnetic nanoparticles, chemotherapy, immunotherapy, magnetic hyperthermia, gene therapy and ferroptosis. Examples of applied treatments on murine models or humans are analyzed, and glioblastoma cancer therapy is detailed in the review. MNPs have an important contribution to diagnostics, investigation, and therapy in the so called theranostics domain. The main conclusion of this paper is that MNPs are very useful in different cancer therapies, with limited side effects, and they can increase the life expectancy of patients with cancer drug resistance.
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http://dx.doi.org/10.3390/ma14205948DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8539633PMC
October 2021

Adhesive-Ceramic Interface Behavior in Dental Restorations. FEM Study and SEM Investigation.

Materials (Basel) 2021 Sep 3;14(17). Epub 2021 Sep 3.

Department of Materials Science and Physical Metallurgy, Faculty of Material Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania.

The purpose of this study is to identify the stress levels that act in inlay and onlay restorations, according to the direction and value of the external force applied. The study was conducted using the Finite Element Method (FEM) of three types of ceramics: pressed lithium disilicate and monolith, zirconia, and three different adhesive systems: self-adhesive, universal, and dual-cure cements. In addition to FEM, the inlay/onlay-dental structure interface analysis was performed by means of Scanning Electron Microscopy (SEM). The geometric models were reconstructed based on computer tomography images of an undamaged molar followed by geometrical procedures of inducing the inlay and onlay reconstructions. The two functional models were then simulated for different orientations of external force and different material properties, according to the considered adhesives and ceramics. The Scanning Electron Microscopy (SEM) was conducted on 30 extracted teeth, divided into three groups according to the adhesive cement type. Both FEM simulation and SEM investigations reveal very good mechanical behavior of the adhesive-dental structure and adhesive-ceramic interfaces for inlay and onlay reconstructions. All results lead to the conclusion that a physiological mastication force applied, regardless of direction, cannot produce a mechanical failure of either inlay or onlay reconstructions. The adhesive bond between the restorations and the dental structure can stabilize the ceramic restorations, resulting in a higher strength to the action of external forces.
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http://dx.doi.org/10.3390/ma14175048DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8433907PMC
September 2021

characterization of novel nanostructured collagen-hydroxyapatite composite scaffolds doped with magnesium with improved biodegradation rate for hard tissue regeneration.

Bioact Mater 2021 Oct 19;6(10):3383-3395. Epub 2021 Mar 19.

Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Via del Fosso del Cavaliere, 100, 00133, Rome, Italy.

New materials are required for bone healing in regenerative medicine able to temporarily substitute damaged bone and to be subsequently resorbed and replaced by endogenous tissues. Taking inspiration from basic composition of the mammalian bones, composed of collagen, apatite and a number of substitution ions, among them magnesium (Mg), in this work, novel composite scaffolds composed of collagen(10%)-hydroxyapatite (HAp)(90%) and collagen(10%)-HAp(80%)-Mg(10%) were developed. The lyophilization was used for composites preparation. An insight into the nanostructural nature of the developed scaffolds was performed by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray and Transmission Electron Microscopy coupled with Energy Dispersive X-Ray. The HAp nanocrystallite clusters and Mg nanoparticles were homogeneously distributed within the scaffolds and adherent to the collagen fibrils. The samples were tested for degradation in Simulated Body Fluid (SBF) solution by soaking for up to 28 days. The release of Mg from collagen(10%)-HAp(80%)-Mg(10%) composite during the period of up to 21 days was attested, this composite being characterized by a decreased degradation rate with respect to the composite without Mg. The developed composite materials are promising for applications as bone substitute materials favouring bone healing and regeneration.
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http://dx.doi.org/10.1016/j.bioactmat.2021.02.030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8005775PMC
October 2021

Comparative Assessment of In Vitro and In Vivo Biodegradation of Mg-1Ca Magnesium Alloys for Orthopedic Applications.

Materials (Basel) 2020 Dec 26;14(1). Epub 2020 Dec 26.

Orthopedics-Traumatology Department, Carol Davila University of Medicine and Pharmacy Bucharest, 3-7 Dionisie Lupu Str., 020022 Bucharest, Romania.

Use of magnesium implants is a new trend in orthopedic research because it has several important properties that recommend it as an excellent resorbable biomaterial for implants. In this study, the corrosion rate and behavior of magnesium alloys during the biodegradation process were determined by in vitro assays, evolution of hydrogen release, and weight loss, and further by in vivo assays (implantation in rabbits' bone and muscle tissue). In these tests, we also used imaging assessments and histological examination of different tissue types near explants. In our study, we analyzed the Mg-1Ca alloy and all the hypotheses regarding the toxic effects found in in vitro studies from the literature and those from this in vitro study were rejected by the data obtained by the in vivo study. Thus, the Mg-1Ca alloy represents a promising solution for orthopedic surgery at the present time, being able to find applicability in the small bones: hand or foot.
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http://dx.doi.org/10.3390/ma14010084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795943PMC
December 2020

Nanoparticles and Nanostructured Surface Fabrication for Innovative Cranial and Maxillofacial Surgery.

Materials (Basel) 2020 Nov 27;13(23). Epub 2020 Nov 27.

Faculty of Materials Sciences Engineering, University Politechnica Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania.

A novel strategy to improve the success of soft and hard tissue integration of titanium implants is the use of nanoparticles coatings made from basically any type of biocompatible substance, which can advantageously enhance the properties of the material, as compared to its similar bulk material. So, most of the physical methods approaches involve the compaction of nanoparticles versus micron-level particles to yield surfaces with nanoscale grain boundaries, simultaneously preserving the chemistry of the surface among different topographies. At the same time, nanoparticles have been known as one of the most effective antibacterial agents and can be used as effective growth inhibitors of various microorganisms as an alternative to antibiotics. In this paper, based on literature research, we present a comprehensive review of the mechanical, physical, and chemical methods for creating nano-structured titanium surfaces along with the main nanoparticles used for the surface modification of titanium implants, the fabrication methods, their main features, and the purpose of use. We also present two patented solutions which involve nanoparticles to be used in cranioplasty, i.e., a cranial endoprosthesis with a sliding system to repair the traumatic defects of the skull, and a cranial implant based on titanium mesh with osteointegrating structures and functional nanoparticles. The main outcomes of the patented solutions are: (a) a novel geometry of the implant that allow both flexible adaptation of the implant to the specific anatomy of the patient and the promotion of regeneration of the bone tissue; (b) porous structure and favorable geometry for the absorption of impregnated active substances and cells proliferation; (c) the new implant model fit 100% on the structure of the cranial defect without inducing mechanical stress; (d) allows all kinds of radiological examinations and rapid osteointegration, along with the patient recover in a shorter time.
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http://dx.doi.org/10.3390/ma13235391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7731022PMC
November 2020

In Vitro Properties of Manganese-Substituted Tricalcium Phosphate Coatings for Titanium Biomedical Implants Deposited by Arc Plasma.

Materials (Basel) 2020 Oct 3;13(19). Epub 2020 Oct 3.

Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Via del Fosso del Cavaliere 100, 00133 Rome, Italy.

Bioactive manganese (Mn)-doped ceramic coatings for intraosseous titanium (Ti) implants are developed. Arc plasma deposition procedure is used for coatings preparation. X-ray Diffraction, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy, and Electron Paramagnetic Resonance (EPR) methods are applied for coatings characterization. The coatings are homogeneous, composed of the main phase α-tricalcium phosphate (α-TCP) (about 67%) and the minor phase hydroxyapatite (about 33%), and the Mn content is 2.3 wt%. EPR spectroscopy demonstrates that the Mn ions are incorporated in the TCP structure and are present in the coating in Mn and Mn oxidation states, being aggregated in clusters. The wetting contact angle of the deposited coatings is suitable for cells' adhesion and proliferation. In vitro soaking in physiological solution for 90 days leads to a drastic change in phase composition; the transformation into calcium carbonate and octacalcium phosphate takes place, and no more Mn is present. The absence of antibacterial activity against bacteria strains is observed. A study of the metabolic activity of mouse fibroblasts of the NCTC L929 cell line on the coatings using the MTT (dye compound 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test demonstrates that there is no toxic effect on the cell culture. Moreover, the coating material supports the adhesion and proliferation of the cells. A good adhesion, spreading, and proliferative activity of the human tooth postnatal dental pulp stem cells (DPSC) is demonstrated. The developed coatings are promising for implant application in orthopedics and dentistry.
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http://dx.doi.org/10.3390/ma13194411DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7579245PMC
October 2020

Tricalcium phosphate cement supplemented with boron nitride nanotubes with enhanced biological properties.

Mater Sci Eng C Mater Biol Appl 2020 Sep 4;114:111044. Epub 2020 May 4.

Department of Mechanical and Aerospace Engineering, University of California Irvine, Engineering Gateway 4200, Irvine, CA, 92697, USA.

A self-setting bone cement containing β-tricalcium phosphate (TCP) supplemented with boron nitride nanotubes (BNNTs, 1 wt%) was synthesized and analyzed in situ for its kinetics of hardening and selected physicochemical and biological properties. Moderately delayed due to the presence of BNNTs, the hardening reaction involved the transformation of the TCP precursor to the dicalcium phosphate (DCPD) product. In spite of the short-lived chemical transformations in the cement upon its hardening, the structural changes in it were extended. As a result, the compressive strength increased from day 1 to day 7 of the hardening reaction and the presence of BNNTs further increased it by ~25%. Fitting of the time-resolved energy-dispersive diffractometric data to the Johnson-Mehl-Avrami-Kolmogorov crystallization kinetics model conformed to the one-dimensional nucleation at a variable rate during the growth of elongated DCPD crystals from round TCP grains. For the first seven days of growth of human mesenchymal stem cells (hMSCs) on the cement, no difference in their proliferation was observed compared to the control. However, between the 7th and the 21st day, the cell proliferation decreased compared to the control because of the ongoing stem cell differentiation toward the osteoblast phenotype. This differentiation was accompanied by the higher expression of alkaline phosphatase, an early marker of hMSC differentiation into a pre-osteoblast phenotype. The TCP cement supplemented with BNNTs was able to thwart the production of reactive oxygen species (ROS) in hMSCs treated with HO/Fe and bring the ROS levels down to the concentrations detected in the control cells, indicating the good capability of the material to protect the cells against the ROS-associated damage. Simultaneously, the cement increased the expression of mediators of inflammation in a co-culture of osteoblasts and macrophages, thus attesting to the direct reciprocity between the degrees of inflammation and stimulated new bone production.
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http://dx.doi.org/10.1016/j.msec.2020.111044DOI Listing
September 2020

Geometric Analysis of Type B Aortic Dissections Shows Aortic Remodeling After Intervention Using Multilayer Stents.

Materials (Basel) 2020 May 15;13(10). Epub 2020 May 15.

NextCardio Project, Lucian Blaga University of Sibiu, 550024 Sibiu, Romania.

Recently, multilayer stents for type B aortic dissections (TBAD) have been proposed to decrease false lumen flow, increase and streamline true lumen flow, and retain branch vessel patency. We aimed to provide a protocol with standardized techniques to investigate aortic remodeling of TBAD by multilayer flow modulators (MFM) in static geometric and hemodynamic analyses. Combining existing literature and new insights, a standardized protocol was designed. Using pre- and postoperative CT scans, geometric models were constructed, lumen dimensions were calculated, computational fluid dynamics (CFD) models were composed, and velocity and pressures were calculated. Sixteen TBAD cases treated with MFM were included for analysis. For each case, aortic remodeling was analyzed using post-processing medical imaging software. After 3D models were created, geometrical anatomical measurements were performed, and meshes for finite element analysis were generated. MFM cases were compared pre- and postoperatively; true lumen volumes increased ( < 0.001), false lumen volumes decreased ( = 0.001), true lumen diameter at the plane of maximum compression (PMC) increased ( < 0.001), and false lumen index decreased ( = 0.008). True lumen flow was streamlined, and the overall fluid velocity and pressures decreased ( < 0.001 and = 0.006, respectively). This protocol provided a standardized method to evaluate the effects of MFM treatments in TBAD on geometric analyses, PMC, and CFD outcomes.
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http://dx.doi.org/10.3390/ma13102274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7287707PMC
May 2020

Synchronous Multiple Breast Cancers-Do We Need to Reshape Staging?

Medicina (Kaunas) 2020 May 11;56(5). Epub 2020 May 11.

Faculty of General Medicine, University of Medicine and Pharmacy Carol Davila Bucharest, 050474 Bucharest, Romania.

Current recommendations and treatment regimens in breast cancer are a reflection of its heterogeneity on multiple levels including histological subtypes, grading, molecular profiling, and numerous prognostic indices. Although based on extensive research, current guidelines are not explicit in the case of surgical specimens showing various degrees of mismatch between different parts of the same tumor and even more so between multicentric lesions. Synchronous breast cancer is the ideal prototype for studying inter- and intra-tumoral heterogeneity, therefore we envisaged that a study on patients with multicentric and multifocal lesions could contribute to the reshaping of the staging, prognosis, and treatment of breast malignancies. A prospective observational study was conducted between January 2013 and May 2017 on 235 patients diagnosed with breast cancer (BC) and surgically treated at Emergency University Hospital, Bucharest. Thirty-seven patients had multiple breast tumors and were eligible for assessment of the heterogeneity of their lesions. : 6 were multicentric and 31 multifocal. The number of foci varied from 2 to 11. We encountered numerous mismatches between the index and the secondary tumors, as follows: 3 cases (8.1%) with histopathological mismatch, 13 (35.1%) with different grades of differentiation, 11 (29.8%) with ER (Estrogen Receptors) status mismatch, 12 (32.4%) with PR (Progesterone Receptors) status mismatch, 8 (21.6%) with molecular phenotype mismatch, and 17 (45.9%) cases with variable Ki-67. After careful analysis of index and secondary tumors, apart from the mismatches reported above, we discovered that the secondary tumors were actually dominant in 5 cases (13.5%), and therefore at least those cases had to be reclassified/restaged, as the supplementary data commanded changes in the therapeutic decision. For synchronous breast tumors, the current Tumor-Node-Metastasis (TNM) staging system ignores not only the histopathological and immunohistochemical characteristics of the secondary foci, but also their size. When secondary lesions are more aggressive or their cumulative mass is significantly bigger than that of the index tumor, the treatment plan should be adapted accordingly. We believe that information obtained from examining secondary foci in synchronous breast cancer and assessment of the cumulative tumoral mass should be reflected in the final staging and definitive treatment. The clinical benefit of staging the patients based on the most aggressive tumor and the cumulative tumoral burden rather than according to the biggest single tumor, will avoid under-treatment in cases with multifocal/multicentric BC displaying intertumoral mismatch.
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http://dx.doi.org/10.3390/medicina56050230DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7279247PMC
May 2020

Novel Hybrid Composites Based on PVA/SeTiO Nanoparticles and Natural Hydroxyapatite for Orthopedic Applications: Correlations between Structural, Morphological and Biocompatibility Properties.

Materials (Basel) 2020 May 1;13(9). Epub 2020 May 1.

Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), Via del Fosso del Cavaliere 100, 00133 Rome, Italy.

The properties of poly(vinyl alcohol) (PVA)-based composites recommend this material as a good candidate for the replacement of damaged cartilage, subchondral bone, meniscus, humeral joint and other orthopedic applications. The manufacturing process can be manipulated to generate the desired biomechanical properties. However, the main shortcomings of PVA hydrogels are related to poor strength and bioactivity. To overcome this situation, reinforcing elements are added to the PVA matrix. The aim of our work was to develop and characterize a novel composition based on PVA reinforced with Se-doped TiO nanoparticles and natural hydroxyapatite (HA), for possible orthopedic applications. The PVA/Se-doped TiO composites with and without HA were structurally investigated by FTIR and XRD, in order to confirm the incorporation of the inorganic phase in the polymeric structure, and by SEM and XRF, to evidence the ultrastructural details and dispersion of nanoparticles in the PVA matrix. Both the mechanical and structural properties of the composites demonstrated a synergic reinforcing effect of HA and Se-doped TiO nanoparticles. Moreover, the tailorable properties of the composites were proved by the viability and differentiation potential of the bone marrow mesenchymal stem cells (BMMSC) to osteogenic, chondrogenic and adipogenic lineages. The novel hybrid PVA composites show suitable structural, mechanical and biological features to be considered as a promising biomaterial for articular cartilage and subchondral bone repair.
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http://dx.doi.org/10.3390/ma13092077DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7254265PMC
May 2020

Failure Analysis of Retrieved Osteosynthesis Implants.

Materials (Basel) 2020 Mar 7;13(5). Epub 2020 Mar 7.

University of Medicine and Pharmacy Carol Davila Bucharest, 050474 Bucharest, Romania.

Failure of osteosynthesis implants is an intricate matter with challenging management that calls for efficient investigation and prevention. Using implant retrieval analysis combined with standard radiological examination, we evaluated the main causes for osteosynthesis implant breakdown and the relations among them for a series of cases. Twenty-one patients diagnosed with implant failure were assessed for this work. For metallurgical analysis, microscopy techniques such as scanning electron microscopy (SEM), stereomicroscopy, and optical microscopy were employed. The results showed that material structural deficiencies (nine patients) and faulty surgical techniques (eight patients) were the main causes for failure. An important number of patients presented with material structural deficiencies superimposed on an imperfect osteosynthesis technique (six patients). Consequently, the importance of failure retrieval analysis should not be overlooked, and in combination with other investigational techniques, must provide information for both implant manufacturing and design improvement, as well as osteosynthesis technique optimization.
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http://dx.doi.org/10.3390/ma13051201DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7085058PMC
March 2020

Fatal outcome of gastric perforation due to infection with Sarcina spp. A case report.

IDCases 2020 11;19:e00711. Epub 2020 Feb 11.

Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.

is an extremely rare pathogen. These gram-positive cocci bacteria are rarely identified in gastric biopsies and usually described in the scientific literature as an incidental finding, particularly in patients with delayed gastric emptying, gastroparesis, emphysematous gastritis or gastric perforation. It occurs most commonly in adult women and can be identified easily by its distinctive morphologic features, such as basophilic staining, cuboidal shape, tetrad arrangement, red blood cell-sized packets, flattened cell walls, and refractile nature in bright field microscopy. Although the pathogenesis of the microorganism is highly debated in humans, this bacterium is a well-known pathogen in livestock. Fewer than 30 cases of human infection have been described in the scientific literature so far, but none mentioned this micro-organism as a potential cause of death. We report the case of a 76-year-old patient with gastric perforation due to massive infection with . To date, this is the first report of human infection with in Romania.
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http://dx.doi.org/10.1016/j.idcr.2020.e00711DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7031000PMC
February 2020

A bioceramic scaffold composed of strontium-doped three-dimensional hydroxyapatite whiskers for enhanced bone regeneration in osteoporotic defects.

Theranostics 2020 1;10(4):1572-1589. Epub 2020 Jan 1.

National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China.

Reconstruction of osteoporotic bone defects is a clinical problem that continues to inspire the design of new materials. : In this work, bioceramics composed of strontium (Sr)-doped hydroxyapatite (HA) whiskers or pure HA whiskers were successfully fabricated by hydrothermal treatment and respectively named SrWCP and WCP. Both bioceramics had similar three-dimensional (3D) porous structures and mechanical strengths, but the SrWCP bioceramic was capable of releasing Sr under physiological conditions. In an osteoporotic rat metaphyseal femoral bone defect model, both bioceramic scaffolds were implanted, and another group that received WCP plus strontium ranelate drug administration (Sr-Ran+WCP) was studied for comparison. : At week 1 post-implantation, osteogenesis coupled blood vessels were found to be more common in the SrWCP and Sr-Ran+WCP groups, with substantial vascular-like structures. After 12 weeks of implantation, comparable to the Sr-Ran+WCP group, the SrWCP group showed induction of more new bone formation within the defect as well as at the implant-bone gap region than that of the WCP group. Both the SrWCP and Sr-Ran+WCP groups yielded a beneficial effect on the surrounding trabecular bone microstructure to resist osteoporosis-induced progressive bone loss. While an abnormally high blood Sr ion concentration was found in the Sr-Ran+WCP group, SrWCP showed little adverse effect. : Our results collectively suggest that the SrWCP bioceramic can be a safe bone substitute for the treatment of osteoporotic bone defects, as it promotes local bone regeneration and implant osseointegration to a level that strontium ranelate can achieve.
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http://dx.doi.org/10.7150/thno.40103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6993240PMC
April 2021

Rare Breast Carcinoma with Paradoxical Plasma Cell Immunoprofile: A Case Report.

Medicina (Kaunas) 2020 Feb 5;56(2). Epub 2020 Feb 5.

Department of Pathology, Regina Maria Central Laboratory, 060044 Bucharest, Romania.

Plasma cell features are encountered in a variety of non-plasma cell neoplasias, especially carcinomas of a discohesive type, such as those occurring in the digestive tract and breast. Lobular carcinomas of the breast present themselves in a variety of architectural patterns and many cell morphologies, including plasmacytoid types. A matching plasma cell phenotype is sometimes an associated feature. We report a case of a moderate grade invasive lobular carcinoma with focal plasmacytoid morphology and aberrant expression of plasma cell markers in a patient previously diagnosed with multiple myeloma. Paradoxical plasma cell immunoprofiles can be encountered in many malignancies, causing serious diagnostic problems, even more so with those occurring in discohesive carcinomas in multiple myeloma patients.
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http://dx.doi.org/10.3390/medicina56020062DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7074448PMC
February 2020

Controlling the Degradation Rate of Biodegradable Mg-Zn-Mn Alloys for Orthopedic Applications by Electrophoretic Deposition of Hydroxyapatite Coating.

Materials (Basel) 2020 Jan 7;13(2). Epub 2020 Jan 7.

Clinical Emergency Hospital Bucharest, Dept.Orthoped. & Traumatol, 8 Floreasca Ave, District 1, 014461 Bucharest, Romania.

Magnesium alloys as bioresorbable materials with good biocompatibility have raised a growing interest in the past years in temporary implant manufacturing, as they offer a steady resorption rate and optimal healing in the body. Magnesium exhibits tensile strength properties similar to those of natural bone, which determines its application in load-bearing mechanical medical devices. In this paper, we investigated the biodegradation rate of Mg-Zn-Mn biodegradable alloys (ZMX410 and ZM21) before and after coating them with hydroxyapatite (HAP) via the electrophoretic deposition method. The experimental samples were subjected to corrosion tests to observe the effect of HAP deposition on corrosion resistance and, implicitly, the rate of biodegradation of these in simulated environments. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) provided detailed information on the quality, structure, and morphology of the HAP coating. The obtained results demonstrate that coating of Mg-Zn-Mn alloys by HAP led to the improvement of corrosion resistance in simulated environments, and that the HAP coating could be used in order to control the biodegradation rate.
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http://dx.doi.org/10.3390/ma13020263DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7013831PMC
January 2020

Investigation of the Microstructure, Hardness and Corrosion Resistance of a New 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn Dental Alloy.

Materials (Basel) 2019 Dec 13;12(24). Epub 2019 Dec 13.

Materials Science and Engineering Faculty, University Politehnica of Bucharest, 313 Splaiul Independentei, PC-060042 Bucharest, Romania.

Higher-noble dental alloys (Au, Ag, and Pd) are the most desirable for dentistry applications, but they are expensive. Low-noble (Ag, Pd, Cu) dental alloys are alternatives to higher-noble ones due to their lower price. In this regard, the paper supports the price lowering of dental alloy by increasing the Cu content, i.e., a new 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn dental alloy. The increasing addition of the Cu leads to a complex structure consisting of a solid solution that engulfs compounds of micrometric and nanometric sizes. The 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn has demonstrated a much better electrochemical corrosion behavior in artificial saliva compared to the Paliag and Unique White dental alloys. The improved corrosion behavior of the new alloy is supported by the diminishing of the Cu selective diffusion into the electrolyte due to its retaining into compounds and into Ag-Pd solid solution. Also, the synergic effects of Cu, Zn, In, Sn may improve the corrosion resistance, but they have strengthened the 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn matrix. The main finding addressed in the paper consists in a new 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn dental alloy with improved corrosion resistance in artificial saliva.
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http://dx.doi.org/10.3390/ma12244199DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6947466PMC
December 2019

Sic Parvis Magna: Manganese-Substituted Tricalcium Phosphate and Its Biophysical Properties.

ACS Biomater Sci Eng 2019 Dec 5;5(12):6632-6644. Epub 2019 Nov 5.

Department of Mechanical and Aerospace Engineering, University of California, Irvine, Engineering Gateway 4200, Irvine, California 92697, United States.

Succeeding in the substitution of pharmaceutical compounds with ions deliverable with the use of resorbable biomaterials could have far-reaching benefits for medicine and economy. Calcium phosphates are known as excellent accommodators of foreign ions. Manganese, the fifth most abundant metal on Earth was studied here as an ionic dopant in β-tricalcium phosphate (β-TCP) ceramics. β-TCP containing different amounts of Mn ions per MnCa(PO) formula ( = 0, 0.001, 0.01, and 0.1) was investigated for a range of physicochemical and biological properties. The results suggested the role of Mn as a structure booster, not breaker. Mn ions increased the size of coherent X-ray scattering regions averaged across all crystallographic directions and also lowered the temperature of transformation of the hydroxyapatite precursor to β-TCP. The particle size increased fivefold, from 20 to 100 nm, in the 650-750 °C region, indicating that the reaction of formation of β-TCP was accompanied by a considerable degree of grain growth. The splitting of the antisymmetric stretching mode of the phosphate tetrahedron occurred proportionally to the Mn content in the material, while electron paramagnetic resonance spectra suggested that Mn might substitute for three out of five possible calcium ion positions in the unit cell of β-TCP. The biological effects of Mn-free β-TCP and Mn-doped β-TCP were selective: moderately proliferative to mammalian cells, moderately inhibitory to bacteria, and insignificant to fungi. Unlike pure β-TCP, β-TCP doped with the highest concentration of Mn ions significantly inhibited the growth of all bacterial species tested: , , , and . The overall effect against the Gram-positive bacteria was more intense than against the Gram-negative microorganisms. Meanwhile, β-TCP alone had an augmentative effect of the viability of adipose-derived mesenchymal stem cells (ADMSCs) and the addition of Mn tended to reduce the extent of this augmentative effect, but without imparting any toxicity. For all Mn-doped β-TCP concentrations except the highest, the cell viability after 72 h incubation was significantly higher than that of the negative control. Assays evaluating the effect of Mn-containing β-TCP formulations on the differentiation of ADMSCs into three different lineages-osteogenic, adipogenic, and chondrogenic-demonstrated no inhibitory or adverse effects compared to pure β-TCP and powder-free positive controls. Still, β-TCP delivering the lowest amount of Mn seemed most effective in sustaining the differentiation process toward all three phenotypes, indicating that the dose of Mn in β-TCP need not be excessive to be effective.
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http://dx.doi.org/10.1021/acsbiomaterials.9b01528DOI Listing
December 2019

Gastric Adenocarcinoma Associated with Acute Endocarditis of the Aortic Valve and Coronary Artery Disease in a 61-Year-Old Male with Multiple Comorbidities-Combined Surgical Management-Case Report.

Medicina (Kaunas) 2019 Jun 3;55(6). Epub 2019 Jun 3.

Iuliu Hatieganu University of Medicine and Pharmacy, 400129 Cluj-Napoca, Romania.

The case of a 61-year-old male with a recent total gastrectomy for a hemorrhagic gastric tumor is presented, with the important co-morbidities of type II diabetes mellitus requiring insulin, chronic hepatitis C with liver dysfunction, stage II essential hypertension, chronic stage III renal disease peripheral type II aorto-iliac disease with stage II ischemia of both legs, and chronic anemia. About one month following the gastrectomy, the patient presented with fever and acute inflammatory syndrome. Severe aortic insufficiency, aortic valvular vegetations, and positive blood cultures with Staphylococcus saprophytic were found. The diagnosis of infectious endocarditis on the aortic valve was established (positive blood cultures with echocardiographic features of vegetations, fever), and antibiotic treatment with Levofloxacin and Vancomycin was initiated. The evolution was favorable with the remission of the inflammatory syndrome and quick cessation of fever. However, the hemodynamic aspect showed progressive heart failure with acute pulmonary edema. The transesophageal echocardiographic examination confirmed the existence of severe aortic insufficiency and valvular vegetations with a left ventricular ejection fraction of 38%. The coronary angiography revealed double vessel disease. The calculated Euroscore II was 33.4%. Aortic valve replacement with porcine xenograft and double coronary artery bypass graft surgery was performed. The patient had a favorable postoperative course remaining afebrile and out of heart failure, with the markers of inflammation largely within normal limits. The left ventricular ejection fraction increased to 50%. The successful outcome of this case, represented by a rare association of cancer, endocarditis, and coronary disease, reveals the importance of the multidisciplinary teams involved in this case: gastroenterology, general surgery, cardiology, infectious diseases, cardiac surgery, and intensive care. Therefore, in such cases with high risk, complex patients, a strong collaboration between all specialties is needed to overcome all of the limitations of the patient's co-morbidities.
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http://dx.doi.org/10.3390/medicina55060242DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6631313PMC
June 2019

Failure Analysis of a Humeral Shaft Locking Compression Plate-Surface Investigation and Simulation by Finite Element Method.

Materials (Basel) 2019 Apr 6;12(7). Epub 2019 Apr 6.

Faculty of Medicine, University Lucian Blaga of Sibiu, 2A Lucian Blaga Str., 550169 Sibiu, Romania.

A case study of a failed humeral shaft locking compression plate is presented, starting with a clinical case where failure occurred and an implant replacement was required. This study uses finite element method (FEM) in order to determine the failure modes for the clinical case. Four loading scenarios that simulate daily life activities were considered for determining the stress distribution in a humeral shaft locking compression plate (LCP). Referring to the simulation results, the failure analysis was performed on the explant. Using fracture surface investigation methods, stereomicroscopy and scanning electron microscopy (SEM), a mixed mode failure was determined. An initial fatigue failure occurred followed by a sudden failure of the plate implant as a consequence of patient's fall. The fracture morphology was mostly masked by galling; the fractured components were in a sliding contact. Using information from simulations, the loading was inferred and correlated with fracture site and surface features.
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http://dx.doi.org/10.3390/ma12071128DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6479305PMC
April 2019

Magnesium Filled Polylactic Acid (PLA) Material for Filament Based 3D Printing.

Materials (Basel) 2019 Mar 1;12(5). Epub 2019 Mar 1.

Faculty of Medicine, University Titu Maiorescu of Bucharest, 040441 Bucharest, Romania.

The main objective of this research is to prove the viability of obtaining magnesium (Mg) filled polylactic acid (PLA) biocomposites as filament feedstock for material extrusion-based additive manufacturing (AM). These materials can be used for medical applications, thus benefiting of all the advantages offered by AM technology in terms of design freedom and product customization. Filaments were produced from two PLA + magnesium + vitamin E (α-tocopherol) compositions and then used for manufacturing test samples and ACL (anterior cruciate ligament) screws on a low-cost 3D printer. Filaments and implant screws were characterized using SEM (scanning electron microscopy), FTIR (fourier transform infrared spectrometry), and DSC (differential scanning calorimetry) analysis. Although the filament manufacturing process could not ensure a uniform distribution of Mg particles within the PLA matrix, a good integration was noticed, probably due to the use of vitamin E as a precursor. The results also show that the composite biomaterials can ensure and maintain implant screws structural integrity during the additive manufacturing process.
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http://dx.doi.org/10.3390/ma12050719DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6427143PMC
March 2019

Naturally-Derived Biphasic Calcium Phosphates through Increased Phosphorus-Based Reagent Amounts for Biomedical Applications.

Materials (Basel) 2019 Jan 25;12(3). Epub 2019 Jan 25.

Department of Metallic Materials Science, Physical Metallurgy, University Politehnica of Bucharest, 313 Splaiul Independentei, J Building, District 6, 060042 Bucharest, Romania.

Calcium carbonate from marble and seashells is an eco-friendly, sustainable, and largely available bioresource for producing natural bone-like calcium phosphates (CaPs). Based on three main objectives, this research targeted the: (i) adaptation of an indirect synthesis route by modulating the amount of phosphorus used in the chemical reaction, (ii) comprehensive structural, morphological, and surface characterization, and (iii) biocompatibility assessment of the synthesized powdered samples. The morphological characterization was performed on digitally processed scanning electron microscopy (SEM) images. The complementary 3D image augmentation of SEM results also allowed the quantification of roughness parameters. The results revealed that both morphology and roughness were modulated through the induced variation of the synthesis parameters. Structural investigation of the samples was performed by Fourier transform infrared spectroscopy and X-ray diffraction. Depending on the phosphorus amount from the chemical reaction, the structural studies revealed the formation of biphasic CaPs based on hydroxyapatite/brushite or brushite/monetite. The assessment of the powdered samples demonstrated their capacity to support MC3T3-E1 pre-osteoblast viability and proliferation at comparable levels to the negative cytotoxicity control and the reference material (commercial hydroxyapatite). Therefore, these samples hold great promise for biomedical applications.
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http://dx.doi.org/10.3390/ma12030381DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384751PMC
January 2019
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