Journal of biomedical materials research. Part B, Applied biomaterials最新文献

The emergence of hybrid scaffolds, blending biomaterials with diverse properties, offers promise in musculoskeletal tissue engineering. However, a need for in vitro platforms investigating biological behavior and the interplay of different load-bearing and colonizable synthetic bone substitute materials remains. Herein, we present a novel, in-house producible, and scalable clamp culture system designed for facile in vitro analysis of interactions between biomaterials, hydrogels, and cells. The system, constructed here from an exemplary 3D-printable polymer and photopolymerizable hydrogel using a widely available benchtop 3D printer, ensures mechanical stability and protection for the embedded hydrogel via its double-clamp structure, facilitating various analytical methods while preserving culture integrity. Hybrid clamp cultures were additively manufactured from polylactic acid, filled with a bone precursor cell-laden methacrylate gelatin hydrogel, cultured for 14 days, and analyzed for cell viability, mineralization, and osseous differentiation. Results indicate no adverse effects on osteogenic differentiation or mineralization compared to conventional droplet cultures, with enhanced cell viability and simplified handling and downstream analysis. This system demonstrates the potential for robust experimentation in tissue engineering and is adaptable to various plate formats, and thus highly suitable for the investigation of biomaterial-cell interactions and the development of implants for musculoskeletal tissue defects.

Regenerative medicine has extended the capacity of medicine to a point where tissues and organs could potentially be manufactured. This could resolve issues associated with organ transplantation. The extracellular matrix (ECM) provides a supportive scaffold and biochemical cues allowing cells to attach, proliferate, and differentiate. The ECM is composed of different fibrous proteins and proteoglycans. The extensive value of ECM lies in its dynamic microenvironment that aids in cell proliferation, differentiation, and regulation of intercellular communication. In this study, four methods were applied to decellularize porcine organs. The ECMs were characterized by histological methods illustrating the absence of nuclei and the presence of glycosaminoglycans (GAGs) and collagen. Hematoxylin and eosin analysis of native pancreas revealed necrosis by auto-digestion, also supported by a reduced dsDNA content, and could have led to the destruction of Type IV collagen, laminins, and other proteins in the resulting ECMs, as confirmed by mass spectrometry. DNA quantification of ECM revealed residual dsDNA contents lower than those of the native organs. Bicinchoninic acid (BCA) assay showed a difference in protein content between organs. Mass spectrometry coupled with proteomic analysis highlighted a significant difference in the protein composition. The number of different proteins, in some cases with more than 2700, in the produced ECM depended on the applied decellularization technique. Polarization microscopy indicated differences in the orientation of collagen fibers. This study provides a multimodal approach to characterize ECMs produced using different decellularization techniques, aiding in finding a balance between maintaining the ultrastructure and composition of ECM, while removing cellular components.

Tissue engineering is a promising approach for generating or repairing living tissues. The development of innovative biomaterials for tissue engineering has the potential to address the unmet clinical needs in certain applications. However, before these biomaterials can be used in clinical settings, they must undergo preclinical testing to ensure safety and performance. The chicken chorioallantoic membrane (CAM) assay is a preferred screening tool for studying biocompatibility, angiogenesis, and inflammation induced by biomaterials owing to ethical and economic considerations. This CAM-based platform increased the throughput of biomaterial testing for tissue engineering before in vivo testing. In this paper, we discuss the advantages of the CAM model. We also provided a step-by-step guide for implementing the CAM model in a research laboratory, along with tips and tricks for successfully running CAM assays. Finally, we present examples of biomaterials screened using CAM assays. CAM assay is a powerful in vivo model for assessing the angiogenic potential of tissue-engineered scaffolds. This guide provides a framework for conducting the assay, but specific experimental conditions should be optimized based on the scaffold material and the research question.

Creating acellular vascularized constructs from animal and plant tissue is one of the well-known strategies for scaffold assembly. Decellularization takes an important position among these strategies. The most common method is chemical decellularization. This approach employs high concentrations of detergents, primarily Triton X-100, sodium dodecyl sulfate (SDS), and sodium hypochlorite (SH). In this work, novel techniques for decellularizing spinach were developed using detergents frequently utilized in laboratories. Spinach leaves were decellularized using Tween-20, SDS, and SH at low concentrations to generate an acellular plant matrix for tissue engineering. We measured the quantities of DNA and protein, as well as the decellularization using hematoxylin and eosin (H&E) staining. The biocompatibility and capacity of the biostructures to stimulate fibroblast wound healing were assessed using MTT and the Scratch assay. The antibacterial activity of the scaffolds was also tested against a gram-positive bacterium, Staphilococcus aureus, which is a common pathogen associated with wound healing. The best shape, evident vascularization, and good biocompatibility were seen in the Tween-20 decellularized samples at 1% concentration at 21°C and 37°C through the enhancement of cell proliferation and wound healing. In terms of antibacterial activity, all scaffold samples had a significant effect on Staphilococcus aureus, where the number of bacterial colonies in all six scaffold groups became zero after 4 h of treatment. The scaffolds also showed a 100% kill rate on Staphilococcus aureus, which could avoid wound infection during the repair process, and that can be suggested as a scaffold for tissue engineering applications and an important constituent for pharmacological activities.

Bacterial cellulose is a unique biomaterial produced by various species of bacteria that offers a range of potential applications in the biomedical field. To provide a cost-effective alternative to soft-tissue implants used in cavity infills, remodeling, and subdermal wound healing, in vitro cytotoxicity and in vivo biocompatibility of native bacterial cellulose were investigated. Cytotoxicity was assessed using a metabolic assay on Swiss 3T3 fibroblasts and INS-1832/13 rat insulinoma. Results showed no cytotoxicity, whether the cells were seeded over or under the bacterial cellulose scaffolds. Biocompatibility was performed on Sprague–Dawley rats (males and females, 8 weeks old) by implanting bacterial cellulose membranes subcutaneously for 1 or 12 weeks. The explanted scaffolds were then sliced and stained with hematoxylin and eosin for histological characterization. The first series of results revealed acute and chronic inflammation persisting over 12 weeks. Examination of the explants indicated a high number of granulocytes within the periphery of the bacterial cellulose, suggesting the presence of endotoxins within the membrane, confirmed by a Limulus amebocyte lysate test. This discovery motivated the development of non-pyrogenic bacterial cellulose scaffolds. Following this, a second series of animal experiments was done, in which materials were implanted for 1 or 2 weeks. The results revealed mild inflammation 1 week after implantation, which then diminished to minimal inflammation after 2 weeks. Altogether, this study highlights that unmodified, purified native bacterial cellulose membranes may be used as a cost-effective biomedical device provided that proper endotoxin clearance is achieved.