Constructing Linear-Oriented Pre-Vascularized Human Spinal Cord Tissues for Spinal Cord Injury Repair.

Repairing spinal cord injury (SCI) is a global medical challenge lacking effective clinical treatment. Developing human-engineered spinal cord tissues that can replenish lost cells and restore a regenerative microenvironment offers promising potential for SCI therapy. However, creating vascularized human spinal cord-like tissues (VSCT) that mimic the diverse cell types and longitudinal parallel structural features of spinal cord tissues remains a significant hurdle. In the present study, VSCTs are engineered using embryonic human spinal cord-derived neural and endothelial cells on linear-ordered collagen scaffolds (LOCS). Studies have shown that astrocytes and endothelial cells align along the scaffolds in VSCT, supporting axon extension from various human neurons myelinated by oligodendrocytes. After transplantation into SCI rats, VSCT survives at the injury sites and promotes endogenous neural regeneration and vascularization, ultimately reducing scarring and enhancing behavioral functional recovery. It suggests that pre-vascularization of engineered spinal cord tissues is beneficial for SCI treatment and highlights the important role of exogenous endothelial cells in tissue engineering.

Advances in biomaterial-based cardiac organoids.

Cardiovascular disease (CVD) is one of the important causes of death worldwide. The incidence and mortality rates are increasing annually with the intensification of social aging. The efficacy of drug therapy is limited in individuals suffering from severe heart failure due to the inability of myocardial cells to undergo regeneration and the challenging nature of cardiac tissue repair following injury. Consequently, surgical transplantation stands as the most efficient approach for treatment. Nevertheless, the shortage of donors and the considerable number of heart failure patients worldwide, estimated at 26 million, results in an alarming treatment deficit, with only around 5000 heart transplants feasible annually. The existing major alternatives, such as mechanical or xenogeneic hearts, have significant flaws, such as high cost and rejection, and are challenging to implement for large-scale, long-term use. An organoid is a three-dimensional (3D) cell tissue that mimics the characteristics of an organ. The critical application has been rated in annual biotechnology by authoritative journals, such as Science and Cell. Related industries have achieved rapid growth in recent years. Based on this technology, cardiac organoids are expected to pave the way for viable heart repair and treatment and play an essential role in pathological research, drug screening, and other areas. This review centers on the examination of biomaterials employed in cardiac repair, strategies employed for the reconstruction of cardiac structure and function, clinical investigations pertaining to cardiac repair, and the prospective applications of cardiac organoids. From basic research to clinical practice, the current status, latest progress, challenges, and prospects of biomaterial-based cardiac repair are summarized and discussed, providing a reference for future exploration and development of cardiac regeneration strategies.