Publications by authors named "Aleksander Skardal"

57 Publications

A Rapid Crosslinkable Maleimide-Modified Hyaluronic Acid and Gelatin Hydrogel Delivery System for Regenerative Applications.

Gels 2021 Feb 1;7(1). Epub 2021 Feb 1.

Department of Biomedical Engineering, The Ohio State University, Fontana Labs., 140 W. 19th Ave, Columbus, OH 43210, USA.

Hydrogels have played a significant role in many applications of regenerative medicine and tissue engineering due to their versatile properties in realizing design and functional requirements. However, as bioengineered solutions are translated towards clinical application, new hurdles and subsequent material requirements can arise. For example, in applications such as cell encapsulation, drug delivery, and biofabrication, in a clinical setting, hydrogels benefit from being comprised of natural extracellular matrix-based materials, but with defined, controllable, and modular properties. Advantages for these clinical applications include ultraviolet light-free and rapid polymerization crosslinking kinetics, and a cell-friendly crosslinking environment that supports cell encapsulation or in situ crosslinking in the presence of cells and tissue. Here we describe the synthesis and characterization of maleimide-modified hyaluronic acid (HA) and gelatin, which are crosslinked using a bifunctional thiolated polyethylene glycol (PEG) crosslinker. Synthesized products were evaluated by proton nuclear magnetic resonance (NMR), ultraviolet visibility spectrometry, size exclusion chromatography, and pH sensitivity, which confirmed successful HA and gelatin modification, molecular weights, and readiness for crosslinking. Gelation testing both by visual and NMR confirmed successful and rapid crosslinking, after which the hydrogels were characterized by rheology, swelling assays, protein release, and barrier function against dextran diffusion. Lastly, biocompatibility was assessed in the presence of human dermal fibroblasts and keratinocytes, showing continued proliferation with or without the hydrogel. These initial studies present a defined, and well-characterized extracellular matrix (ECM)-based hydrogel platform with versatile properties suitable for a variety of applications in regenerative medicine and tissue engineering.
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http://dx.doi.org/10.3390/gels7010013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7931058PMC
February 2021

3D scaffold-free microlivers with drug metabolic function generated by lineage-reprogrammed hepatocytes from human fibroblasts.

Biomaterials 2021 02 8;269:120668. Epub 2021 Jan 8.

Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA. Electronic address:

Generating microliver tissues to recapitulate hepatic function is of increasing importance in tissue engineering and drug screening. But the limited availability of primary hepatocytes and the marked loss of phenotype hinders their application. Human induced hepatocytes (hiHeps) generated by direct reprogramming can address the shortage of primary hepatocytes to make personalized drug prediction possible. Here, we simplify preparation of reprogramming reagents by expressing six transcriptional factors (HNF4A, FOXA2, FOXA3, ATF5, PROX1, and HNF1) from two lentiviral vectors, each expressing three factors. Transducing human fetal and adult fibroblasts with low vector dosage generated human induced hepatocyte-like cells (hiHeps) displaying characteristics of mature hepatocytes and capable of drug metabolism. To mimic the physiologic liver microenvironment and improve hepatocyte function, we prepared 3D scaffold-free microliver spheroids using hiHeps and human liver nonparenchymal cells through self-assembly without exogenous scaffolds. We then introduced the microliver spheroids into a two-organ microfluidic system to examine interactions between hepatocytes and tumor cells. The hiHeps-derived spheroids metabolized the prodrug capecitabine into the active metabolite 5-fluorouracil and induced toxicity in downstream tumor spheroids. Our results demonstrate that hiHeps can be used to make microliver spheroids and combined with a microfluidic system for drug evaluation. Our work could make it possible to use patient-specific hepatocyte-like cells to predict drug efficacy and side effects in various organs from the same patient.
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http://dx.doi.org/10.1016/j.biomaterials.2021.120668DOI Listing
February 2021

Multi-Cell Type Glioblastoma Tumor Spheroids for Evaluating Sub-Population-Specific Drug Response.

Front Bioeng Biotechnol 2020 15;8:538663. Epub 2020 Sep 15.

Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States.

Glioblastoma (GBM) is a lethal, incurable form of cancer in the brain. Even with maximally aggressive surgery and chemoradiotherapy, median patient survival is 14.5 months. These tumors infiltrate normal brain tissue, are surgically incurable, and universally recur. GBMs are characterized by genetic, epigenetic, and microenvironmental heterogeneity, and they evolve spontaneously over time and as a result of treatment. However, tracking such heterogeneity in real time in response to drug treatments has been impossible. Here we describe the development of an GBM tumor organoid model that is comprised of five distinct cellular subpopulations (4 GBM cell lines that represent GBM subpopulations and 1 astrocyte line), each fluorescently labeled with a different color. These multi-cell type GBM organoids are then embedded in a brain-like hyaluronic acid hydrogel for subsequent studies involving drug treatments and tracking of changes in relative numbers of each fluorescently unique subpopulation. This approach allows for the visual assessment of drug influence on individual subpopulations within GBM, and in future work can be expanded to supporting studies using patient tumor biospecimen-derived cells for personalized diagnostics.
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http://dx.doi.org/10.3389/fbioe.2020.538663DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7523412PMC
September 2020

Personalized Identification of Optimal HIPEC Perfusion Protocol in Patient-Derived Tumor Organoid Platform.

Ann Surg Oncol 2020 Dec 6;27(13):4950-4960. Epub 2020 Jul 6.

Wake Forest Organoid Research Center (WFORCE), Wake Forest School of Medicine, Winston-Salem, NC, USA.

Background: Chemotherapy dosing duration and perfusion temperature vary significantly in HIPEC protocols. This study investigates patient-derived tumor organoids as a platform to identify the most efficacious perfusion protocol in a personalized approach.

Patients And Methods: Peritoneal tumor tissue from 15 appendiceal and 8 colon cancer patients who underwent CRS/HIPEC were used for personalized organoid development. Organoids were perfused in parallel at 37 and 42 °C with low- and high-dose oxaliplatin (200 mg/m over 2 h vs. 460 mg/m over 30 min) and MMC (40 mg/3L over 2 h). Viability assays were performed and pooled for statistical analysis.

Results: An adequate organoid number was generated for 75% (6/8) of colon and 73% (11/15) of appendiceal patients. All 42 °C treatments displayed lower viability than 37 °C treatments. On pooled analysis, MMC and 200 mg/m oxaliplatin displayed no treatment difference for either appendiceal or colon organoids (19% vs. 25%, p = 0.22 and 27% vs. 31%, p = 0.55, respectively), whereas heated MMC was superior to 460 mg/m oxaliplatin in both primaries (19% vs. 54%, p < 0.001 and 27% vs. 53%, p = 0.002, respectively). In both appendiceal and colon tumor organoids, heated 200 mg/m oxaliplatin displayed increased cytotoxicity as compared with 460 mg/m oxaliplatin (25% vs. 54%, p < 0.001 and 31% vs. 53%, p = 0.008, respectively).

Conclusions: Organoids treated with MMC or 200 mg/m heated oxaliplatin for 2 h displayed increased susceptibility in comparison with 30-min 460 mg/m oxaliplatin. Optimal perfusion protocol varies among patients, and organoid technology may offer a platform for tailoring HIPEC conditions to the individual patient level.
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http://dx.doi.org/10.1245/s10434-020-08790-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7674215PMC
December 2020

Simulating the human colorectal cancer microenvironment in 3D tumor-stroma co-cultures in vitro and in vivo.

Sci Rep 2020 06 17;10(1):9832. Epub 2020 Jun 17.

Wake Forest Baptist Medical Center, Winston-Salem, NC, 27101, USA.

The tumor microenvironment (TME) plays a significant role in cancer progression and thus modeling it will advance our understanding of cancer growth dynamics and response to therapies. Most in vitro models are not exposed to intact body physiology, and at the same time, fail to recapitulate the extensive features of the tumor stroma. Conversely, animal models do not accurately capture the human tumor architecture. We address these deficiencies with biofabricated colorectal cancer (CRC) tissue equivalents, which are built to replicate architectural features of biopsied CRC tissue. Our data shows that tumor-stroma co-cultures consisting of aligned extracellular matrix (ECM) fibers and ordered micro-architecture induced an epithelial phenotype in CRC cells while disordered ECM drove a mesenchymal phenotype, similar to well and poorly differentiated tumors, respectively. Importantly, co-cultures studied in vitro, and upon implantation in mice, revealed similar tumor growth dynamics and retention of architectural features for 28 days. Altogether, these results are the first demonstration of replicating human tumor ECM architecture in ex vivo and in vivo cultures.
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http://dx.doi.org/10.1038/s41598-020-66785-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7300090PMC
June 2020

Multi-Domain Photopatterned 3D Tumor Constructs in a Micro-Physiological System for Analysis, Quantification, and Isolation of Infiltrating Cells.

Adv Biosyst 2020 04 25;4(4):e1900273. Epub 2020 Feb 25.

Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.

Cancer cell motility plays a central role in metastasis and tumor invasion but can be difficult to study accurately in vitro. A simple approach to address this challenge through the production of monolithic, photopatterned 3D tumor constructs in situ in a microfluidic device is described here. Through step-wise fabrication of adjoining hydrogel regions with and without incorporated cells, multidomain structures with defined boundaries are produced. By imaging cells over time, cellular activity with arbitrary control over medium conditions, including drug concentration and flow rate, is studied. First, malignant human colon carcinoma cells (HCT116) are studied for 10 days, comparing invasion dynamics and viability of cells in normal media to those exposed to two independent chemotherapeutic drugs: anti-proliferative 5-fluorouracil and anti-migratory Marimastat. Cytotoxicity is measured and significant differences are observed in cellular dynamics (migrating cell count, distance traveled, and rate) that correlate with the mechanism of each drug. Then, the platform is applied to the selective isolation of infiltrated cells through the photopatterning and subsequent dissolution of cleavable hydrogel domains. As a demonstration, the preferential collection of highly migratory cells (HCT116) over a comparable cell line with low malignancy and migratory potential (Caco-2) is shown.
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http://dx.doi.org/10.1002/adbi.201900273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7323471PMC
April 2020

ASO Author Reflections: Co-cultured Lymph Node and Tumor Organoids as a Platform for the Creation of Adaptive Immunity and Predict Response to Immunotherapy.

Ann Surg Oncol 2020 Jun 17;27(6):1968-1969. Epub 2020 Mar 17.

Wake Forest Institute for Regenerative Medicine, Winston-Salem, USA.

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http://dx.doi.org/10.1245/s10434-020-08351-7DOI Listing
June 2020

Drug compound screening in single and integrated multi-organoid body-on-a-chip systems.

Biofabrication 2020 02 26;12(2):025017. Epub 2020 Feb 26.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27101, United States of America. Department of Biomedical Engineering, The Ohio State University, 1080 Carmack Road, Columbus, OH, 43210, United States of America.

Current practices in drug development have led to therapeutic compounds being approved for widespread use in humans, only to be later withdrawn due to unanticipated toxicity. These occurrences are largely the result of erroneous data generated by in vivo and in vitro preclinical models that do not accurately recapitulate human physiology. Herein, a human primary cell- and stem cell-derived 3D organoid technology is employed to screen a panel of drugs that were recalled from market by the FDA. The platform is comprised of multiple tissue organoid types that remain viable for at least 28 days, in vitro. For many of these compounds, the 3D organoid system was able to demonstrate toxicity. Furthermore, organoids exposed to non-toxic compounds remained viable at clinically relevant doses. Additional experiments were performed on integrated multi-organoid systems containing liver, cardiac, lung, vascular, testis, colon, and brain. These integrated systems proved to maintain viability and expressed functional biomarkers, long-term. Examples are provided that demonstrate how multi-organoid 'body-on-a-chip' systems may be used to model the interdependent metabolism and downstream effects of drugs across multiple tissues in a single platform. Such 3D in vitro systems represent a more physiologically relevant model for drug screening and will likely reduce the cost and failure rate associated with the approval of new drugs.
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http://dx.doi.org/10.1088/1758-5090/ab6d36DOI Listing
February 2020

Immersion Bioprinting of Tumor Organoids in Multi-Well Plates for Increasing Chemotherapy Screening Throughput.

Micromachines (Basel) 2020 Feb 18;11(2). Epub 2020 Feb 18.

Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA.

The current drug development pipeline takes approximately fifteen years and $2.6 billion to get a new drug to market. Typically, drugs are tested on two-dimensional (2D) cell cultures and animal models to estimate their efficacy before reaching human trials. However, these models are often not representative of the human body. The 2D culture changes the morphology and physiology of cells, and animal models often have a vastly different anatomy and physiology than humans. The use of bioengineered human cell-based organoids may increase the probability of success during human trials by providing human-specific preclinical data. They could also be deployed for personalized medicine diagnostics to optimize therapies in diseases such as cancer. However, one limitation in employing organoids in drug screening has been the difficulty in creating large numbers of homogeneous organoids in form factors compatible with high-throughput screening (e.g., 96- and 384-well plates). Bioprinting can be used to scale up deposition of such organoids and tissue constructs. Unfortunately, it has been challenging to 3D print hydrogel bioinks into small-sized wells due to well-bioink interactions that can result in bioinks spreading out and wetting the well surface instead of maintaining a spherical form. Here, we demonstrate an immersion printing technique to bioprint tissue organoids in 96-well plates to increase the throughput of 3D drug screening. A hydrogel bioink comprised of hyaluronic acid and collagen is bioprinted into a viscous gelatin bath, which blocks the bioink from interacting with the well walls and provides support to maintain a spherical form. This method was validated using several cancerous cell lines, and then applied to patient-derived glioblastoma (GBM) and sarcoma biospecimens for drug screening.
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http://dx.doi.org/10.3390/mi11020208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7074680PMC
February 2020

Probing prodrug metabolism and reciprocal toxicity with an integrated and humanized multi-tissue organ-on-a-chip platform.

Acta Biomater 2020 04 14;106:124-135. Epub 2020 Feb 14.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA; Virginia Tech -Wake Forest School of Biomedical Engineering and Sciences, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA; Comprehensive Cancer Center of Wake Forest Baptist, Wake Forest Baptist Medical Center, Medical Center Boulevard, Winston-Salem, NC 27157; Department of Biomedical Engineering, The Ohio State University, 1080 Carmack Rd., Columbus, OH 43210; The Ohio State University Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, 460 W 10th Ave, Columbus, OH 43210. Electronic address:

Current drug development techniques are expensive and inefficient, partially due to the use of preclinical models that do not accurately recapitulate in vivo drug efficacy and cytotoxicity. To address this challenge, we report on an integrated, in vitro multi-organoid system that enables parallel assessment of drug efficiency and toxicity on multiple 3D tissue organoids. Built in a low-cost, adhesive film-based microfluidic device, these miniaturized structures require less than 200 µL fluid volume and are amenable to both matrix-based 3D cell culture and spheroid aggregate integration, each supported with an in situ photocrosslinkable hyaluronic acid hydrogel. Here, we demonstrate this technology first with a three-organoid device consisting of liver, cardiac, and lung constructs. We show that these multiple tissue types can be kept in common circulation with high viability for 21 days and validate the platform by investigating liver metabolism of the prodrug capecitabine into 5-fluorouracil (5-FU) and observing downstream toxicity in lung and cardiac organoids. Then we expand the integrated system to accommodate six humanized constructs, including liver, cardiac, lung, endothelium, brain, and testes organoids. Following a 14-day incubation in common media, we demonstrate multi-tissue interactions by metabolizing the alkylating prodrug ifosfamide in the liver organoid to produce chloroacetaldehyde and induce downstream neurotoxicity. Our results establish an expandable, multi-organoid body-on-a-chip system that can be fabricated easily and used for the accurate characterization of drug interactions in vitro. STATEMENT OF SIGNIFICANCE: The use of 3-dimensional (3D) in vitro models in drug development has advanced over the past decade. However, with several exceptions, the majority of research studies using 3D in vitro models, such as organoids, employ single tissue types, in isolated environments with no "communication" between different tissues. This is a significant limiting factor because in the human body there is significant signaling between different cells, tissues, and organs. Here we employ a low-cost, adhesive film-based microfluidic device approach, paired with a versatile extracellular matrix-derived hyaluronic acid hydrogel to support integrated systems of 3 and 6 3D organoid and cell constructs. Moreover, we demonstrate an integrated response to drugs, in which downstream toxicity is dependent on the presence of liver organoids.
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http://dx.doi.org/10.1016/j.actbio.2020.02.015DOI Listing
April 2020

Model of Patient-Specific Immune-Enhanced Organoids for Immunotherapy Screening: Feasibility Study.

Ann Surg Oncol 2020 Jun 19;27(6):1956-1967. Epub 2019 Dec 19.

Comprehensive Cancer Center at Wake Forest Baptist Medical, Medical Center Boulevard, Winston-Salem, NC, USA.

Introduction: We hypothesized that engineering a combined lymph node/melanoma organoid from the same patient would allow tumor, stroma, and immune system to remain viable for personalized immunotherapy screening.

Methods: Surgically obtained matched melanoma and lymph node biospecimens from the same patient were transferred to the laboratory and washed with saline, antibiotic, and red blood cell lysis buffer. Biospecimens were dissociated, incorporated into an extracellular matrix (ECM)-based hydrogel system, and biofabricated into three dimensional (3D) mixed melanoma/node organoids. Cells were not sorted, so as to preserve tumor heterogeneity, including stroma and immune cell components, resulting in immune-enhanced patient tumor organoids (iPTOs). Organoid sets were screened in parallel with nivolumab, pembrolizumab, ipilimumab, and dabrafenib/trametinib for 72 h. LIVE/DEAD staining and quantitative metabolism assays recorded relative drug efficacy. Histology and immunohistochemistry were used to compare tumor melanoma cells with organoid melanoma cells. Lastly, node-enhanced iPTOs were employed to activate patient-matched peripheral blood T cells for killing of tumor cells in naïve PTOs.

Results: Ten biospecimen sets obtained from eight stage III and IV melanoma patients were reconstructed as symbiotic immune/tumor organoids between September 2017 and June 2018. Successful establishment of viable organoid sets was 90% (9/10), although organoid yield varied with biospecimen size. Average time from organoid development to initiation of immunotherapy testing was 7 days. In three patients for whom a node was not available, it was substituted with peripheral blood mononuclear cells. iPTO response to immunotherapy was similar to specimen clinical response in 85% (6/7) patients. In an additional pilot study, peripheral T cells were circulated through iPTOs, and subsequently transferred to naïve PTOs from the same patient, resulting in tumor killing, suggesting a possible role of iPTOs in generating adaptive immunity.

Conclusion: Development of 3D mixed immune-enhanced tumor/node organoids is a feasible platform, allowing individual patient immune system and tumor cells to remain viable for studying of personalized immunotherapy response.
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http://dx.doi.org/10.1245/s10434-019-08143-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7474462PMC
June 2020

Pleural Effusion Aspirate for use in 3D Lung Cancer Modeling and Chemotherapy Screening.

ACS Biomater Sci Eng 2019 Apr 8;5(4):1937-1943. Epub 2019 Mar 8.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, 391 Technology Way, Winston-Salem, NC, 27101, USA.

Lung cancer is the leading cause of cancer-related death worldwide yet disease models have been limited to traditional 2D culture utilizing cancer cell lines. In contrast, recently developed 3D models (organoids) have been adopted by researchers to improve the physiological relevance of laboratory study. We have hypothesized that 3D hydrogel-based models will allow for improved disease replication and characterization over standard 2D culture using cells taken directly from patients. Here, we have leveraged the use of 3D hydrogel-based models to create lung cancer organoids using a unique cell source, pleural effusion aspirate, from multiple lung cancer patients. With these 3D models, we have characterized the cell populations comprising the pleural effusion aspirate and have tracked phenotypic changes that develop during short-term culture. We found that isolated, patient cells placed directly into organoids created anatomically relevant structures and exhibited lung cancer specific behaviors. On the other hand, cells first grown in plastic dishes and then cultured in 3D did not create similar structures. Further, we have been able to compare chemotherapeutic response of patient cells between 2D and 3D cell culture systems. Our results show that cells in 2D culture were more sensitive to treatment when compared with 3D organoids. Collectively, we have been able to utilize tumor cells from pleural effusion fluid of lung cancer patients to create organoids that display like anatomy and drug response and thus could serve as more accurate disease models for study of tumor progression and drug development.
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http://dx.doi.org/10.1021/acsbiomaterials.8b01356DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6853614PMC
April 2019

Deconstructed Microfluidic Bone Marrow On-A-Chip to Study Normal and Malignant Hemopoietic Cell-Niche Interactions.

Small 2019 10 29;15(43):e1902971. Epub 2019 Aug 29.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, 391 Technology Way, Winston-Salem, NC, 27101, USA.

Human hematopoietic niches are complex specialized microenvironments that maintain and regulate hematopoietic stem and progenitor cells (HSPC). Thus far, most of the studies performed investigating alterations of HSPC-niche dynamic interactions are conducted in animal models. Herein, organ microengineering with microfluidics is combined to develop a human bone marrow (BM)-on-a-chip with an integrated recirculating perfusion system that consolidates a variety of important parameters such as 3D architecture, cell-cell/cell-matrix interactions, and circulation, allowing a better mimicry of in vivo conditions. The complex BM environment is deconvoluted to 4 major distinct, but integrated, tissue-engineered 3D niche constructs housed within a single, closed, recirculating microfluidic device system, and equipped with cell tracking technology. It is shown that this technology successfully enables the identification and quantification of preferential interactions-homing and retention-of circulating normal and malignant HSPC with distinct niches.
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http://dx.doi.org/10.1002/smll.201902971DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8011350PMC
October 2019

Amnion membrane hydrogel and amnion membrane powder accelerate wound healing in a full thickness porcine skin wound model.

Stem Cells Transl Med 2020 01 21;9(1):80-92. Epub 2019 Jul 21.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina.

There is a need for effective wound treatments that retain the bioactivity of a cellular treatment, but without the high costs and complexities associated with manufacturing, storing, and applying living biological products. Previously, we developed an amnion membrane-derived hydrogel and evaluated its wound healing properties using a mouse wound model. In this study, we used a full thickness porcine skin wound model to evaluate the wound-healing efficacy of the amnion hydrogel and a less-processed amnion product comprising a lyophilized amnion membrane powder. These products were compared with commercially available amnion and nonamnion wound healing products. We found that the amnion hydrogel and amnion powder treatments demonstrated significant and rapid wound healing, driven primarily by new epithelialization versus closure by contraction. Histological analysis demonstrated that these treatments promote the formation of a mature epidermis and dermis with similar composition to healthy skin. The positive skin regenerative outcomes using amnion hydrogel and amnion powder treatments in a large animal model further demonstrate their potential translational value for human wound treatments.
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http://dx.doi.org/10.1002/sctm.19-0101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6954699PMC
January 2020

Development of a Colorectal Cancer 3D Micro-tumor Construct Platform From Cell Lines and Patient Tumor Biospecimens for Standard-of-Care and Experimental Drug Screening.

Ann Biomed Eng 2020 Mar 24;48(3):940-952. Epub 2019 Apr 24.

Department of Cancer Biology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.

Colorectal cancer is subject to a high rate of mutations, with late stage tumors often containing many mutations. These tumors are difficult to treat, and even with the recently implemented methods of personalized medicine at modern hospitals aiming to narrow treatments, a gap still exists. Proper modeling of these tumors may help to recommend optimal treatments for individual patients, preferably utilizing a model that maintains proper signaling in respect to the derived parent tissue. In this study, we utilized an extracellular matrix-derived hydrogel to create a 3D micro-tumor construct platform capable of both supporting cells for long time durations and for high throughput drug screening. Experiments with cell lines demonstrated long-term viability with maintenance of cell proliferation. Furthermore, studies with several chemotherapeutics utilizing different mechanisms of action displayed differences in efficacy in comparing 3D and 2D cultures. Finally, patient colorectal tumor tissue was acquired and employed to reconstruct micro-tumor constructs, providing a system for the testing of novel chemotherapeutics against tumors in a patient-specific manner. Collectively, the results describe a system capable of high throughput testing while maintaining important characteristics of the parent tissue.
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http://dx.doi.org/10.1007/s10439-019-02269-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6813880PMC
March 2020

3D bioprinting for high-throughput screening: Drug screening, disease modeling, and precision medicine applications.

Appl Phys Rev 2019 Mar 6;6(1). Epub 2019 Feb 6.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center, Winston-Salem, North Carolina 27101, USA.

High-throughput technologies have become essential in many fields of pharmaceutical and biological development and production. Such technologies were initially developed with compatibility with liquid handling-based cell culture techniques to produce large-scale 2D cell culture experiments for the compound analysis of candidate drug compounds. Over the past two decades, tools for creating 3D cell cultures, organoids, and other 3D models, such as cell supportive biomaterials and 3D bioprinting, have rapidly advanced. Concurrently, a significant body of evidence has accumulated which speaks to the many benefits that 3D model systems have over traditional 2D cell cultures. Specifically, 3D cellular models better mimic aspects such as diffusion kinetics, cell-cell interactions, cell-matrix interactions, inclusion of stroma, and other features native to tissue and as such have become an integral part of academic research. However, most high throughput assays were not developed to specifically support 3D systems. Here, we describe the need for improved compatibility and relevant advances toward deployment and adoption of high throughput 3D models to improve disease modeling, drug efficacy testing, and precision medicine applications.
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http://dx.doi.org/10.1063/1.5056188DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7968875PMC
March 2019

In Situ Bioprinting of Autologous Skin Cells Accelerates Wound Healing of Extensive Excisional Full-Thickness Wounds.

Sci Rep 2019 02 12;9(1):1856. Epub 2019 Feb 12.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.

The early treatment and rapid closure of acute or chronic wounds is essential for normal healing and prevention of hypertrophic scarring. The use of split thickness autografts is often limited by the availability of a suitable area of healthy donor skin to harvest. Cellular and non-cellular biological skin-equivalents are commonly used as an alternative treatment option for these patients, however these treatments usually involve multiple surgical procedures and associated with high costs of production and repeated wound treatment. Here we describe a novel design and a proof-of-concept validation of a mobile skin bioprinting system that provides rapid on-site management of extensive wounds. Integrated imaging technology facilitated the precise delivery of either autologous or allogeneic dermal fibroblasts and epidermal keratinocytes directly into an injured area, replicating the layered skin structure. Excisional wounds bioprinted with layered autologous dermal fibroblasts and epidermal keratinocytes in a hydrogel carrier showed rapid wound closure, reduced contraction and accelerated re-epithelialization. These regenerated tissues had a dermal structure and composition similar to healthy skin, with extensive collagen deposition arranged in large, organized fibers, extensive mature vascular formation and proliferating keratinocytes.
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http://dx.doi.org/10.1038/s41598-018-38366-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6372693PMC
February 2019

A multi-site metastasis-on-a-chip microphysiological system for assessing metastatic preference of cancer cells.

Biotechnol Bioeng 2019 04 31;116(4):936-944. Epub 2018 Dec 31.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center, Winston-Salem, North Carolina.

Metastatic disease remains one of the primary reasons for cancer-related deaths, yet the majority of in vitro cancer models focus on the primary tumor sites. Here, we describe a metastasis-on-a-chip device that houses multiple bioengineered three-dimensional (3D) organoids, established by a 3D photopatterning technique employing extracellular matrix-derived hydrogel biomaterials. Specifically, cancer cells begin in colorectal cancer (CRC) organoid, which resides in a single microfluidic chamber connected to multiple downstream chambers in which liver, lung, and endothelial constructs are housed. Under recirculating fluid flow, tumor cells grow in the primary site, eventually enter circulation, and can be tracked via fluorescent imaging. Importantly, we describe that in the current version of this platform, HCT116 CRC cells preferentially home to the liver and lung constructs; the corresponding organs of which CRC metastases arise the most in human patients. We believe that in subsequent studies this platform can be implemented to better understand the mechanisms underlying metastasis, perhaps resulting in the identification of targets for intervention.
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http://dx.doi.org/10.1002/bit.26871DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6399040PMC
April 2019

Appendiceal Cancer Patient-Specific Tumor Organoid Model for Predicting Chemotherapy Efficacy Prior to Initiation of Treatment: A Feasibility Study.

Ann Surg Oncol 2019 Jan 9;26(1):139-147. Epub 2018 Nov 9.

Comprehensive Cancer Center at Wake Forest Baptist Medical, Winston-Salem, NC, USA.

Introduction: We have hypothesized that biofabrication of appendiceal tumor organoids allows for a more personalized clinical approach and facilitates research in a rare disease.

Methods: Appendiceal cancer specimens obtained during cytoreduction with hyperthermic intraperitoneal chemotherapy procedures (CRS/HIPEC) were dissociated and incorporated into an extracellular matrix-based hydrogel system as three-dimensional (3D), patient-specific tumor organoids. Cells were not sorted, preserving tumor heterogeneity, including stroma and immune cell components. Following establishment of organoid sets, chemotherapy drugs were screened in parallel. Live/dead staining and quantitative metabolism assays recorded which chemotherapies were most effective in killing cancer cells for a specific patient. Maintenance of cancer phenotypes were confirmed by using immunohistochemistry.

Results: Biospecimens from 12 patients were applied for organoid development between November 2016 and May 2018. Successful establishment rate of viable organoid sets was 75% (9/12). Average time from organoid development to chemotherapy testing was 7 days. These tumors included three high-grade appendiceal (HGA) and nine low-grade appendiceal (LGA) primaries obtained from sites of peritoneal metastasis. All tumor organoids were tested with chemotherapeutic agents exhibited responses that were either similar to the patient response or within the variability of the expected clinical response. More specifically, HGA tumor organoids derived from different patients demonstrated variable chemotherapy tumor-killing responses, whereas LGA organoids tested with the same regimens showed no response to chemotherapy. One LGA set of organoids was immune-enhanced with cells from a patient-matched lymph node to demonstrate feasibility of a symbiotic 3D reconstruction of a patient matched tumor and immune system component.

Conclusions: Development of 3D appendiceal tumor organoids is feasible even in low cellularity LGA tumors, allowing for individual patient tumors to remain viable for research and personalized drug screening.
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http://dx.doi.org/10.1245/s10434-018-7008-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7992871PMC
January 2019

Optimization of collagen type I-hyaluronan hybrid bioink for 3D bioprinted liver microenvironments.

Biofabrication 2018 10 30;11(1):015003. Epub 2018 Oct 30.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, 391 Technology Way, Winston-Salem, NC, 27101, United States of America. Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, United States of America.

Current 3D printing of tissue is restricted by the use of biomaterials that do not recapitulate the native properties of the extracellular matrix (ECM). These restrictions have thus far prevented optimization of composition and structure of the in vivo tissue microenvironment. The artificial nature of currently used biomaterials affects cellular phenotype and function of the bioprinted tissues, and results in inaccurate modeling of disease and drug metabolism significantly. Collagen type I is the major structural component in the ECM, and is widely used as a 3D hydrogel, but is less applicable for 3D bioprinting due to low viscosity and slow polymerization. We have hypothesized that a combination of hyaluronic acid with collagen I yields a bioink with the properties required for extrusion bioprinting, while supporting native cell-matrix interactions and preservation of the native microenvironment properties. To test this hypothesis, we tested the viscoelastic properties of three bioink formulations -2:1, 3:1, and 4:1 collagen type I to hyaluronic acid, and examined cellular behavior in order to determine an optimal formulation that allows for bioprinting while supporting biological activity. We then employed this formulation to bioprint 3D liver tissue constructs containing primary human hepatocytes and liver stellate cells and tested the effects of acetaminophen, a common liver toxicant. Our results have shown that the combination of methacrylated collagen type I and thiolated hyaluronic acid yield a simple, printable bioink that allows for modulation that was directly related to stromal cell elongation. Further, the bioink adequately allowed for implementation as a support hydrogel for hepatocytes which were able to remain viable over two weeks and responded to drug treatment appropriately.
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http://dx.doi.org/10.1088/1758-5090/aae543DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8008502PMC
October 2018

Peritoneal Metastases from Appendiceal Cancer.

Surg Oncol Clin N Am 2018 07;27(3):551-561

Surgical Oncology Service, Department of General Surgery, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.

The early symptoms of appendiceal cancer may mimic the clinical picture of appendicitis. Most patients are diagnosed incidentally during surgical exploration or late when peritoneal or systemic dissemination has already occurred, as colonoscopy rarely will diagnose an appendiceal cancer. Systemic/extraperitoneal metastases are distinctly unusual for appendiceal mucinous lesions.
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http://dx.doi.org/10.1016/j.soc.2018.02.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8159158PMC
July 2018

Environmental Toxin Screening Using Human-Derived 3D Bioengineered Liver and Cardiac Organoids.

Front Public Health 2018 16;6:103. Epub 2018 Apr 16.

Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine, Medical Center, Winston-Salem, NC, United States.

Introduction: Environmental toxins, such as lead and other heavy metals, pesticides, and other compounds, represent a significant health concern within the USA and around the world. Even in the twenty-first century, a plethora of cities and towns in the U.S. have suffered from exposures to lead in drinking water or other heavy metals in food or the earth, while there is a high possibility of further places to suffer such exposures in the near future.

Methods: We employed bioengineered 3D human liver and cardiac organoids to screen a panel of environmental toxins (lead, mercury, thallium, and glyphosate), and charted the response of the organoids to these compounds. Liver and cardiac organoids were exposed to lead (10 µM-10 mM), mercury (200 nM-200 µM), thallium (10 nM-10 µM), or glyphosate (25 µM-25 mM) for a duration of 48 h. The impacts of toxin exposure were then assessed by LIVE/DEAD viability and cytotoxicity staining, measuring ATP activity and determining IC50 values, and determining changes in cardiac organoid beating activity.

Results: As expected, all of the toxins induced toxicity in the organoids. Both ATP and LIVE/DEAD assays showed toxicity in both liver and cardiac organoids. In particular, thallium was the most toxic, with IC50 values of 13.5 and 1.35 µM in liver and cardiac organoids, respectively. Conversely, glyphosate was the least toxic of the four compounds, with IC50 values of 10.53 and 10.85 mM in liver and cardiac organoids, respectively. Additionally, toxins had a negative influence on cardiac organoid beating activity as well. Thallium resulting in the most significant decreases in beating rate, followed by mercury, then glyphosate, and finally, lead. These results suggest that the 3D organoids have significant utility to be deployed in additional toxicity screening applications, and future development of treatments to mitigate exposures.

Conclusion: 3D organoids have significant utility to be deployed in additional toxicity screening applications, such as future development of treatments to mitigate exposures, drug screening, and environmental toxin detection.
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http://dx.doi.org/10.3389/fpubh.2018.00103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5932352PMC
April 2018

Label-free analysis of physiological hyaluronan size distribution with a solid-state nanopore sensor.

Nat Commun 2018 03 12;9(1):1037. Epub 2018 Mar 12.

Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Wake Forest School of Medicine, Winston-Salem, NC, 27101, USA.

Hyaluronan (or hyaluronic acid, HA) is a ubiquitous molecule that plays critical roles in numerous physiological functions in vivo, including tissue hydration, inflammation, and joint lubrication. Both the abundance and size distribution of HA in biological fluids are recognized as robust indicators of various pathologies and disease progressions. However, such analyses remain challenging because conventional methods are not sufficiently sensitive, have limited dynamic range, and/or are only semi-quantitative. Here we demonstrate label-free detection and molecular weight discrimination of HA with a solid-state nanopore sensor. We first employ synthetic HA polymers to validate the measurement approach and then use the platform to determine the size distribution of as little as 10 ng of HA extracted directly from synovial fluid in an equine model of osteoarthritis. Our results establish a quantitative method for assessment of a significant molecular biomarker that bridges a gap in the current state of the art.
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http://dx.doi.org/10.1038/s41467-018-03439-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5847568PMC
March 2018

In vitro patient-derived 3D mesothelioma tumor organoids facilitate patient-centric therapeutic screening.

Sci Rep 2018 02 13;8(1):2886. Epub 2018 Feb 13.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center, Winston-Salem, NC, 27101, USA.

Variability in patient response to anti-cancer drugs is currently addressed by relating genetic mutations to chemotherapy through precision medicine. However, practical benefits of precision medicine to therapy design are less clear. Even after identification of mutations, oncologists are often left with several drug options, and for some patients there is no definitive treatment solution. There is a need for model systems to help predict personalized responses to chemotherapeutics. We have microengineered 3D tumor organoids directly from fresh tumor biopsies to provide patient-specific models with which treatment optimization can be performed before initiation of therapy. We demonstrate the initial implementation of this platform using tumor biospecimens surgically removed from two mesothelioma patients. First, we show the ability to biofabricate and maintain viable 3D tumor constructs within a tumor-on-a-chip microfluidic device. Second, we demonstrate that results of on-chip chemotherapy screening mimic those observed in subjects themselves. Finally, we demonstrate mutation-specific drug testing by considering the results of precision medicine genetic screening and confirming the effectiveness of the non-standard compound 3-deazaneplanocin A for an identified mutation. This patient-derived tumor organoid strategy is adaptable to a wide variety of cancers and may provide a framework with which to improve efforts in precision medicine oncology.
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http://dx.doi.org/10.1038/s41598-018-21200-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5811529PMC
February 2018

Hyaluronan chemistries for three-dimensional matrix applications.

Matrix Biol 2019 05 10;78-79:337-345. Epub 2018 Feb 10.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center, Winston-Salem, NC, 27101, USA; Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA; Comprehensive Cancer Center at Wake Forest Baptist Medical, Medical Center Boulevard, Winston-Salem, NC 27157, USA; Department of Cancer Biology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA. Electronic address:

Hyaluronan is a ubiquitous constituent of mammalian extracellular matrices and, because of its excellent intrinsic biocompatibility and chemical modification versatility, has been widely employed in a multitude of biomedical applications. In this article, we will survey the approaches used to tailor hyaluronan to specific needs of tissue engineering, regenerative and reconstructive medicine and overall biomedical research. We will also describe recent examples of applications in these broader areas, such as 3D cell culture, bioprinting, organoid biofabrication, and precision medicine that are facilitated by the use of hyaluronan as a biomaterial.
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http://dx.doi.org/10.1016/j.matbio.2018.02.010DOI Listing
May 2019

Applications of Bioengineered 3D Tissue and Tumor Organoids in Drug Development and Precision Medicine: Current and Future.

BioDrugs 2018 Feb;32(1):53-68

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27101, USA.

Over the past decade, advances in biomedical and tissue engineering technologies, such as cell culture techniques, biomaterials, and biofabrication, have driven increasingly widespread use of three-dimensional (3D) cell culture platforms and, subsequently, the use of organoids in a variety of research endeavors. Given the 3D nature of these organoid systems, and the frequent inclusion of extracellular matrix components, these constructs typically have more physiologically accurate cell-cell and cell-matrix interactions than traditional 2D cell cultures. As a result, 3D organoids can serve as better model systems than their 2D counterparts. Moreover, as organoids can be biofabricated from highly functional human cells, they have certain advantages over animal models, being human in nature and more easily manipulated in the laboratory. In this review, we describe such organoid technologies and their deployment in drug development and precision medicine efforts. Organoid technologies are rapidly being developed for these applications and now represent a wide variety of tissue types and diseases. Evidence is emerging that organoids are poised for widespread adoption, not only in academia but also in the pharmaceutical industry and in clinical diagnostic applications, positioning them as indispensable tools in medicine.
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http://dx.doi.org/10.1007/s40259-017-0258-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7995645PMC
February 2018

Solubilized Amnion Membrane Hyaluronic Acid Hydrogel Accelerates Full-Thickness Wound Healing.

Stem Cells Transl Med 2017 11 23;6(11):2020-2032. Epub 2017 Sep 23.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, USA.

The early and effective treatment of wounds is vital to ensure proper wound closure and healing with appropriate functional and cosmetic outcomes. The use of human amnion membranes for wound care has been shown to be safe and effective. However, the difficulty in handling and placing thin sheets of membrane, and the high costs associated with the use of living cellularized tissue has limited the clinical application of amniotic membrane wound healing products. Here, we describe a novel amnion membrane-derived product, processed to result in a cell-free solution, while maintaining high concentrations of cell-derived cytokines and growth factors. The solubilized amnion membrane (SAM) combined with the carrier hyaluronic acid (HA) hydrogel (HA-SAM) is easy to produce, store, and apply to wounds. We demonstrated the efficacy of HA-SAM as a wound treatment using a full-thickness murine wound model. HA-SAM significantly accelerated wound closure through re-epithelialization and prevented wound contraction. HA-SAM-treated wounds had thicker regenerated skin, increased total number of blood vessels, and greater numbers of proliferating keratinocytes within the epidermis. Overall, this study confirms the efficacy of the amnion membrane as a wound treatment/dressing, and overcomes many of the limitations associated with using fresh, cryopreserved, or dehydrated tissue by providing a hydrogel delivery system for SAM. Stem Cells Translational Medicine 2017;6:2020-2032.
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http://dx.doi.org/10.1002/sctm.17-0053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6430059PMC
November 2017

Bioengineered Submucosal Organoids for In Vitro Modeling of Colorectal Cancer.

Tissue Eng Part A 2017 10;23(19-20):1026-1041

1 Wake Forest Institute for Regenerative Medicine , Wake Forest School of Medicine, Winston-Salem, North Carolina.

The physical nature of the tumor microenvironment significantly impacts tumor growth, invasion, and response to drugs. Most in vitro tumor models are designed to study the effects of extracellular matrix (ECM) stiffness on tumor cells, while not addressing the effects of ECM's specific topography. In this study, we bioengineered submucosal organoids, using primary smooth muscle cells embedded in collagen I hydrogel, which produce aligned and parallel fiber topography similar to those found in vivo. The fiber organization in the submucosal organoids induced an epithelial phenotype in spheroids of colorectal carcinoma cells (HCT-116), which were embedded within the organoids. Conversely, unorganized fibers drove a mesenchymal phenotype in the tumor cells. HCT-116 cells in organoids with aligned fibers showed no WNT signaling activation, and conversely, WNT signaling activation was observed in organoids with disrupted fibers. Consequently, HCT-116 cells in the aligned condition exhibited decreased cellular proliferation and reduced sensitivity to 5-fluorouracil chemotherapeutic treatment compared to cells in the unorganized construct. Collectively, the results establish a unique colorectal tumor organoid model to study the effects of stromal topography on cancer cell phenotype, proliferation, and ultimately, chemotherapeutic susceptibility. In the future, such organoids can utilize patient-derived cells for precision medicine applications.
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http://dx.doi.org/10.1089/ten.tea.2017.0397DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5653148PMC
October 2017

Tissue-specific extracellular matrix promotes myogenic differentiation of human muscle progenitor cells on gelatin and heparin conjugated alginate hydrogels.

Acta Biomater 2017 10 17;62:222-233. Epub 2017 Aug 17.

Wake Forest Institute for Regenerative Medicine, 391 Technology Way, Winston-Salem, NC, USA; Hypertension and Vascular Research Center, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, USA; Center on Diabetes, Obesity, and Metabolism, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, USA. Electronic address:

Myogenic differentiation, cell fusion, and myotube formation of skeletal muscle progenitor cells (SMPCs) have key roles during skeletal muscle development and repair. However, after isolation from living tissue and transition to culture dishes, SMPCs gradually lose their function and stop propagating due to the absence of extracellular matrix (ECM). Despite encouraging results of experiments using ECM components in cell culture for maintenance and propagation of some tissue types, the benefits of this approach on SMPC culture are limited, because the bioactive molecules and proteins instantly release and are degraded during culture. In this study, we developed a novel approach to enhance the proliferation and differentiation of human skeletal muscle progenitor cells (hSMPCs) in vitro with skeletal muscle ECM in combination with a modified alginate hydrogel conjugated with gelatin and heparin (Alg-G-H) as a substrate. This Alg-G-H substrate, together with skeletal muscle ECM, significantly enhanced cell expansion, differentiation, and maturation of hSMPCs compared with individual substrata (i.e. gelatin, Matrigel®, or ECM alone). In Western-blot and immunocytochemical analyses, the Alg-G-H-ECM predominantly enhanced expression of skeletal myogenesis markers (MyoD, Myf5, Myogenin, Desmin and Myosin) and myotube formation in hSMPCs. This study demonstrated that combining Alg-G-H substrates with skeletal muscle ECM modulated homeostasis of cell proliferation, differentiation, and maturation of hSMPCs by releasing signaling molecules and growth factors. This technique could be a cost-effective tool for in vitro skeletal muscle cell differentiation and maturation, with potential applications in tissue regeneration and drug development.

Statement Of Significance: Alginate based biomaterials are commonly used in tissue engineering and regenerative medicine field, however, the inefficient sequestration of growth factors restricted its utilization. In this study, a novel alginate based substrates was produced covalently modified with gelatin and heparin, in order to capture more effective cytokines and proteins in the culture milieu, keep homeostasis for cell survival and tissue regeneration with growth factor sequestration and long-term release capacities. Combining with skeletal muscle derived ECM, the modified Alginate-Gelatin-Heparin gel could most effectively mimic the tissue specific microenvironment to support skeletal muscle progenitor cells proliferation, differentiation and myotube formation. Additionally, the economical and practical features will make it more promising in high-throughput application for regenerative medicine research.
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http://dx.doi.org/10.1016/j.actbio.2017.08.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151673PMC
October 2017

Multi-tissue interactions in an integrated three-tissue organ-on-a-chip platform.

Sci Rep 2017 08 18;7(1):8837. Epub 2017 Aug 18.

Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA.

Many drugs have progressed through preclinical and clinical trials and have been available - for years in some cases - before being recalled by the FDA for unanticipated toxicity in humans. One reason for such poor translation from drug candidate to successful use is a lack of model systems that accurately recapitulate normal tissue function of human organs and their response to drug compounds. Moreover, tissues in the body do not exist in isolation, but reside in a highly integrated and dynamically interactive environment, in which actions in one tissue can affect other downstream tissues. Few engineered model systems, including the growing variety of organoid and organ-on-a-chip platforms, have so far reflected the interactive nature of the human body. To address this challenge, we have developed an assortment of bioengineered tissue organoids and tissue constructs that are integrated in a closed circulatory perfusion system, facilitating inter-organ responses. We describe a three-tissue organ-on-a-chip system, comprised of liver, heart, and lung, and highlight examples of inter-organ responses to drug administration. We observe drug responses that depend on inter-tissue interaction, illustrating the value of multiple tissue integration for in vitro study of both the efficacy of and side effects associated with candidate drugs.
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http://dx.doi.org/10.1038/s41598-017-08879-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5562747PMC
August 2017