International Journal of Extreme Manufacturing最新文献

In this study, we present the development of a cryobioink designed to fabricate anisotropic scaffolds that support both neural and muscle cell alignment. Given the critical role of cellular organization in nerve fibers and neuromuscular junctions, we employed a vertical cryobioprinting-enabled ice-templating technique to create scaffolds with aligned microchannels. These channels facilitated cell alignment, which is important in modeling neural and neuromuscular tissues. By integrating hyaluronic acid-methacrylate (HAMA) with gelatin methacryloyl and the necessary cryoprotective agent melezitose, we showcased that the cryobioink could preserve cell viability during freezing/thawing processes, even at low temperatures employed during cryobioprinting. We optimized HAMA concentration to enhance neural cell viability and alignment, and successfully constructed anisotropic scaffolds featuring distinct sections that contained muscle and neural cells, establishing a model for neuromuscular junctions. The resulting models provide a versatile platform for studying nerve fibers and neuromuscular dysfunctions, offering potential advancements in neural regeneration research.

This comprehensive review explores the multifaceted landscape of skin bioprinting, revolutionizing dermatological research. The applications of skin bioprinting utilizing techniques like extrusion-, droplet-, laser- and light-based methods, with specialized bioinks for skin biofabrication have been critically reviewed along with the intricate aspects of bioprinting hair follicles, sweat glands, and achieving skin pigmentation. Challenges remain with the need for vascularization, safety concerns, and the integration of automated processes for effective clinical translation. The review further investigates the incorporation of biosensor technologies, emphasizing their role in monitoring and enhancing the wound healing process. While highlighting the remarkable progress in the field, critical limitations and concerns are critically examined to provide a balanced perspective. This synthesis aims to guide scientists, engineers, and healthcare providers, fostering a deeper understanding of the current state, challenges, and future directions in skin bioprinting for transformative applications in tissue engineering and regenerative medicine.

Degenerative spine pathologies, including intervertebral disc (IVD) degeneration, present a significant healthcare challenge due to their association with chronic pain and disability. This study explores an innovative approach to IVD regeneration utilizing 3D bioprinting technology, specifically visible light-based digital light processing (VL-DLP), to fabricate tissue scaffolds that closely mimic the native architecture of the IVD. Utilizing a hybrid bioink composed of gelatin methacrylate (GelMA) and poly (ethylene glycol) diacrylate (PEGDA) at a 10% concentration, we achieved enhanced printing fidelity and mechanical properties suitable for load-bearing applications such as the IVD. Preconditioning rat bone marrow-derived mesenchymal stem cell (rBMSC) spheroids with chondrogenic media before incorporating them into the GelMA-PEGDA scaffold further promoted the regenerative capabilities of this system. Our findings demonstrate that this bioprinted scaffold not only supports cell viability and integration but also contributes to the restoration of disc height in a rat caudal disc model without inducing adverse inflammatory responses. The study underscores the potential of combining advanced bioprinting techniques and cell preconditioning strategies to develop effective treatments for IVD degeneration and other musculoskeletal disorders, highlighting the need for further research into the dynamic interplay between cellular migration and the hydrogel matrix.

Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum (Ta)-Copper (Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological, mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta (10Ta) and 3 wt.% Cu (3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e. 78%-86% with respect to CpTi. Mechanical properties for Ti3Al2V-10Ta-3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with 10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse inflammatory response in vivo. Our results establish the Ti3Al2V-10Ta-3Cu alloy's synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.