Journal of biomedical materials research. Part A最新文献

Premature implant failure, a critical concern in biomedical applications, is often attributed to poor biocompatibility and vulnerability to bacterial colonization. These issues are addressed by creating an endoprosthetic material with natural biocompatibility and antibacterial properties. In this in vitro study, the relaxed and unrelaxed tetrahedral amorphous carbon (ta-C) coatings were examined, both fabricated by the improved patented Pulsed Laser Deposition (PLD) technology. The chemical composition, surface roughness, hardness, topography, and wettability were analyzed. The ta-C surfaces were incubated by MM6 cells, E. coli and S. capitis bacteria for 24 h. PCR assessed the inflammatory response in MM6 cells, while fluorescence microscopy quantified adhering bacteria, and scanning electron microscopy examined local adhesion behavior. The results demonstrate comparable carbon phase composition, wettability properties, and hardness for both relaxed and unrelaxed ta-C. However, relaxed ta-C coating exhibited significantly fewer defects in terms of both quantity and quality, along with an antibacterial effect against E. coli. This suggests that the relaxed ta-C coating could contribute to the development of an endoprosthesis, preventing adverse biological reactions and implant-related infections, thus improving the longevity of the prosthesis.

In recent years, the exploration of sustainable alternatives in the field of bone tissue engineering has led researchers to focus on marine waste byproducts as a valuable resource. These marine resources, often overlooked remnants of various industries, exhibit a rich composition of hydroxyapatite, collagen, calcium carbonate, and other minerals essential to the complex framework of bone structure. Marine waste by-products can emit gases such as methane and carbon dioxide, highlighting the urgency to repurpose these materials for innovative tissue regeneration solutions, offering a sustainable approach to address environmental challenges while advancing medical science. Using these discarded materials offers a promising pathway for sustainable development in regenerative medicine. This review investigates the distinctive properties of marine waste byproducts, emphasizing their capacity to be recycled effectively to contribute to the rebuilding of bone and cartilage tissue during regeneration processes. We also highlight the compatibility of these resources with biological materials such as platelet-rich plasma (PRP), stem cells, exosomes, and natural bioproducts, as well as nanoparticles (NPs) and polymers. By using the natural potential of these resources, we simultaneously address environmental challenges and promote innovative solutions in skeletal tissue engineering, initiating a new era of environmentally green biomedical research.

Many patients suffer from peripheral nerve injury, which can impair their quality of life. Restoring nerve tissue is difficult due to the low ability of nerves to regenerate. Nerve conduits are designed to help peripheral nerve regeneration by providing a scaffold that can match the tissue characteristics, facilitate cellular activities, and be easily implanted. In order to provide a nerve conduit having scaffolding properties, conductance cytocompatibility, we have investigated the potential of channeled structures made of poly (glycerol-sebacate) (PGS) elastomer containing carbon nanofibers (CNFs) in the regeneration of nerve tissue. The first step was to synthesize PGS elastomer and tune its properties to match the nerve tissue. Then, a carbon dioxide laser was used to create micro channels on the elastomer surface for guiding nerve cells. The PGS elastomer was blended with carbon nanofiber (CNF), which was functionalized to bond with the elastomer, to form a conductive structure. The constructs were investigated in terms of cell behavior using PC12 and S42 cell lines. A statistically significant increase in cell proliferation was observed in both cell lines. It was found that the cells began to grow along the canal in places. In terms of elasticity, conductance and cell response, these constructs may be a potential candidate for nerve tissue engineering.

Over the past decade, there has been growing interest in developing microspheres for embolization procedures. However, the lack of noninvasive monitoring of the embolic agents and the occurrence of reflux phenomenon leading to unintentional occlusions has raised concerns regarding their compatibility/suitability for embolization therapy. Here we report the development of specialty microspheres having intrinsic radiopacity and surface functionality to tackle the existing complications that pave the way for more advanced solutions. To achieve the above goal, an iodinated monomer, termed "IBHV," capable of imparting radiopacity and functionality, was synthesized and used as a chain extender to make radiopaque polyurethane. Microspheres with a smooth surface and an average diameter of 474 ± 73 μm were fabricated from this polyurethane. The microspheres obtained were noncytotoxic, had a permissible hemolysis rate, and showed better traceability on x-ray imaging. Subsequent immobilization of thrombin onto microspheres improved their hemostatic effect. This study demonstrated that immobilization of thrombin would lead to microspheres with unique traits of radiopacity and hemostatic properties, which will undoubtedly enhance embolization efficiency.

This study developed a shape memory polyurethane foam (SM-PUF) with tunable mechanical properties and exceptional radiation tolerance for potentially implanting tissue defects after mastectomy. The PUFs were synthesized via an in situ foaming strategy using water as a foaming agent, incorporating 4,4'-diphenylmethane diisocyanate (MDI) as the rigid segment and both polyoxytetramethylene glycol and polycaprolactone as the soft segment. The resultant PUFs possess an open-cell structure with a pore size of 30 ~ 800 μm, which achieves a compressive stress of 0.04 MPa under 70% compression strain and a tensile elongation of 667.9%. PUFs exhibit body temperature (37°C)-responsive softening and shape memory abilities, with recovery and fixation ratios reaching 88% and 98%, respectively. It was verified that PUFs can resist 40 Gy radiotherapy without changing their mechanical properties and biocompatibility. This study introduces an innovative approach to produce customizable foam for the reconstruction of implant prostheses for the breast.

3D bioprinting can generate the organized structures found in human skin for a variety of biological, medical, and pharmaceutical applications. Challenges in bioprinting skin include printing different types of cells in the same construct while maintaining their viability, which depends on the type of bioprinter and bioinks used. This study evaluated a novel 3D bioprinted skin model containing human keratinocytes (HEKa) and human dermal fibroblasts (HDF) in co-culture (CC) using a high-viscosity fibrin-based bioink produced using the BioX extrusion-based bioprinter. The constructs containing HEKa or HDF cells alone (control groups) and in CC were evaluated at 1, 10, and 20 days after bioprinting for viability, immunocytochemistry for specific markers (K5 and K10 for keratinocytes; vimentin and fibroblast specific protein [FSP] for fibroblasts). The storage, loss modulus, and viscosity properties of the constructs were also assessed to compare the effects of keratinocytes and fibroblasts individually and combined, providing important insights when bioprinting skin. Our findings revealed significantly higher cell viability in the CC group compared to individual keratinocyte and fibroblast groups, suggesting the combined cell presence enhanced survival rates. Additionally, proliferation rates of both cell types remained consistent over time, indicating non-competitive growth within the construct. Interestingly, keratinocytes exhibited a greater impact on the viscoelastic properties of the construct compared to fibroblasts, likely due to their larger size and arrangement. These insights contribute to optimizing bioprinting strategies for skin tissue engineering and emphasize the important role of different cell types in 3D skin models.

The alveolar-capillary interface is the key functional element of gas exchange in the human lung, and disruptions to this interface can lead to significant medical complications. However, it is currently challenging to adequately model this interface in vitro, as it requires not only the co-culture of human alveolar epithelial and endothelial cells but mainly the preparation of a biocompatible scaffold that mimics the basement membrane. This scaffold should support cell seeding from both sides, and maintain optimal cell adhesion, growth, and differentiation conditions. Our study investigates the use of polycaprolactone (PCL) nanofibers as a versatile substrate for such cell cultures, aiming to model the alveolar-capillary interface more accurately. We optimized nanofiber production parameters, utilized polyamide mesh UHELON as a mechanical support for scaffold handling, and created 3D-printed inserts for specialized co-cultures. Our findings confirm that PCL nanofibrous scaffolds are manageable and support the co-culture of diverse cell types, effectively enabling cell attachment, proliferation, and differentiation. Our research establishes a proof-of-concept model for the alveolar-capillary interface, offering significant potential for enhancing cell-based testing and advancing tissue-engineering applications that require specific nanofibrous matrices.

The majority of issues related to patients suffering from conductive hearing loss and repeated otitis media are due to chronic tympanic membrane perforations. This generally requires a surgical procedure called tympanoplasty to seal the perforation where autologous grafts are used to reconstruct the membrane. However, the limitations associated with surgical procedures and the limited graft-material availability often cause difficulties in this route; demanding novel procedures or materials. The basic requirements for a synthetic graft-material for this application cover excellent cell adherence with no immune response and inflammatory actions at the site of implantation along with wound-healing characteristics and sufficient acoustic and mechanical properties. With this aim, an innovative graft material has been developed with polyvinyl alcohol (PVA) as the base component through this work. To ensure better cell adhesion and proliferation, a natural polymer, gelatin, has been cross-linked with PVA through a maleic anhydride (MA) intermediate; with a two-step synthesis protocol. The mechanical strength of graft material has been found to be tunable by adjusting the ratio of gelatin with PVA. Laser Doppler Vibrometry (LDV) has been employed to evaluate its acoustic properties upon exposure to a frequency sweep of 10-8000 Hz. The in vitro biocompatibility assays using L929 and RPMI 2650 cells substantiate the material's compatibility; ensuring its potential clinical applications toward chronic tympanic membrane perforations.

Magnetic nanoparticles (MNPs) are produced for both diagnosis and treatment due to their simultaneous availability in magnetic resonance imaging (MRI) and magnetic hyperthermia (MHT). Extensive investigations focus on developing MNPs for individual MHT or MRI applications, but the development of MNPs for theragnostic applications has received very little attention. In this study, through efficient examination of synthesis conditions such as metal precursors, reaction parameters, and solvent choices, we aimed to optimize MNP production for effective utilization for MHT and MRI simultaneously. MNPs were synthesized by thermal decomposition under 17 different conditions and deeply characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The heating efficiency of MNPs under an alternating current (AC) magnetic field was quantified, while MRI performance was evaluated through agar phantom experiments. Our findings highlight the crucial role of benzyl ether in metal ion reduction and size control. Metal-doped iron oxide MNPs displayed promise for MHT, whereas Mn-doped iron oxide MNPs exhibited enhanced MRI capabilities. Consequently, five engineered MNPs were considered potential candidates for further studies, demonstrating their dual ability in MRI and MHT.

The vitreous humor undergoes liquefaction with age, resulting in complications that may require a vitrectomy, or surgical removal of the vitreous from the eye. Silicone oil, a common vitreous substitute, lacks properties similar to the natural vitreous. In particular, it lacks antioxidants that may be necessary to reduce oxidative stress in the eye. The purpose of this study was to evaluate antioxidant-loaded hydrogel vitreous substitutes in a pilot in vivo study. Ascorbic acid and glutathione were loaded into synthesized PEGDA hydrogels. Following vitrectomy, experimental antioxidant hydrogels or silicone oil were injected into one eye of rabbits, while the other eye served as untreated or sham control. Ophthalmic assessments, including electroretinography, were performed. Levels of glutathione and ascorbic acid were higher in the eyes treated with the antioxidant-loaded hydrogel vitreous substitute, although this was not found to be significant after 28 days. There were no statistically significant differences between groups with respect to clinical examination, and ocular health scores, electroretinograms, and histology were normal. These results indicate minimal concerns for the hydrogel formulation or high levels of antioxidants. Future research will assess the capability of vitreous substitutes to prolong antioxidant release, with the goal of minimizing cataract after vitrectomy.