Microfiber Fabricated via Microfluidic Spinning toward Tissue Engineering Applications

Covalently cross-linked ultrastrong SiO2-loaded polyvinyl alcohol fibers via microfluidic spinning

Polyvinyl alcohol (PVA) fiber materials have gained immense recognition due to their good biocompatibility and wide applications. However, methods allowing the synergistic enhancement of mechanical strength and toughness of PVA fibers still remain a key challenge. To this end, we developed covalently cross-linked ultrastrong SiO2-loaded polyvinyl alcohol fibers via a microfluidic spinning chemistry strategy. The thermal stretching and annealing processes not only promote the ordered arrangement of molecules, but also facilitate the ring opening reaction and increase crystallinity. Thus, the resulting fiber has a high tensile strength of 866 MPa, a specific toughness of 288 J g-1 and a tensile strain of 80%. This work provides a covalent cross-linking reinforcement method to prepare ultrastrong composite fibers assisted by microfluidic spinning chemistry and thermal stretching, which would lead to the fabrication of mechanically strong fiber materials through a simple pathway.

Advances in Microfluidic Technologies in Organoid Research

Organoids have emerged as major technological breakthroughs and novel organ models that have revolutionized biomedical research by recapitulating the key structural and functional complexities of their in vivo counterparts. The combination of organoid systems and microfluidic technologies has opened new frontiers in organoid engineering and offers great opportunities to address the current challenges of existing organoid systems and broaden their biomedical applications. In this review, the key features of the existing organoids, including their origins, development, design principles, and limitations, are described. Then the recent progress in integrating organoids into microfluidic systems is highlighted, involving microarrays for high-throughput organoid manipulation, microreactors for organoid hydrogel scaffold fabrication, and microfluidic chips for functional organoid culture. The opportunities in the nascent combination of organoids and microfluidics that lie ahead to accelerate research in organ development, disease studies, drug screening, and regenerative medicine are also discussed. Finally, the challenges and future perspectives in the development of advanced microfluidic platforms and modified technologies for building organoids with higher fidelity and standardization are envisioned.

Hollow Microfiber Assembly-Based Endocrine Pancreas-on-a-Chip for Sugar Substitute Evaluation

With the increasing demand for low-sugar, low-calorie healthy diets, artificial sweeteners are widely used as substitutes for sugar in the food industry. Therefore, developing models that can better predict the effects of sugar substitutes on the human body is necessary. Here, a new type of endocrine pancreas-on-a-chip is developed based on a microfiber assembly and its stimulation of pancreatic secretion by glucose or sugar substitutes is evaluated. This new endocrine pancreas-on-a-chip is assembled using two components: (1) a cell-loaded hollow methacrylate gelatin (GelMA)/calcium alginate (CaA) composite microfiber prepared by microfluidic spinning to achieve vascular simulation and material transport, and (2) a 3D pancreatic islet culture layer, which also serves as a fiber assembly microchip. Using this established organ chip, the effects of five sweeteners (glucose, erythritol, xylitol, sodium cyclamate, and sucralose) were investigated on pancreatic islet cell viability and insulin and glucagon secretion. The constructed endocrine pancreas-on-a-chip has potential for the safety evaluation of sugar-substituted food additives, which can expand the application of organ chips in the field of food safety and provide a new platform for evaluating various food additives.

Evaluation and Application of Silk Fibroin Based Biomaterials to Promote Cartilage Regeneration in Osteoarthritis Therapy

Osteoarthritis (OA) is a common joint disease characterized by cartilage damage and degeneration. Traditional treatments such as NSAIDs and joint replacement surgery only relieve pain and do not achieve complete cartilage regeneration. Silk fibroin (SF) biomaterials are novel materials that have been widely studied and applied to cartilage regeneration. By mimicking the fibrous structure and biological activity of collagen, SF biomaterials can promote the proliferation and differentiation of chondrocytes and contribute to the formation of new cartilage tissue. In addition, SF biomaterials have good biocompatibility and biodegradability and can be gradually absorbed and metabolized by the human body. Studies in recent years have shown that SF biomaterials have great potential in treating OA and show good clinical efficacy. Therefore, SF biomaterials are expected to be an effective treatment option for promoting cartilage regeneration and repair in patients with OA. This article provides an overview of the biological characteristics of SF, its role in bone and cartilage injuries, and its prospects in clinical applications to provide new perspectives and references for the field of bone and cartilage repair.

Recent Advances in Decellularized Extracellular Matrix-Based Bioinks for 3D Bioprinting in Tissue Engineering

In recent years, three-dimensional (3D) bioprinting has been widely utilized as a novel manufacturing technique by more and more researchers to construct various tissue substitutes with complex architectures and geometries. Different biomaterials, including natural and synthetic materials, have been manufactured into bioinks for tissue regeneration using 3D bioprinting. Among the natural biomaterials derived from various natural tissues or organs, the decellularized extracellular matrix (dECM) has a complex internal structure and a variety of bioactive factors that provide mechanistic, biophysical, and biochemical signals for tissue regeneration and remodeling. In recent years, more and more researchers have been developing the dECM as a novel bioink for the construction of tissue substitutes. Compared with other bioinks, the various ECM components in dECM-based bioink can regulate cellular functions, modulate the tissue regeneration process, and adjust tissue remodeling. Therefore, we conducted this review to discuss the current status of and perspectives on dECM-based bioinks for bioprinting in tissue engineering. In addition, the various bioprinting techniques and decellularization methods were also discussed in this study.