Research Progress on the Application of 3D Printing Technology for Adipose and Skeletal Tissue Repair

Abstract

Severe skin trauma can be caused by acids, alkalis, heat, and burns. Due to alterations in the wound microenvironment and massive loss or death of cells, wound healing is difficult. Tissue damage is primarily repaired by cells. Stem cell injection therapy is a research hotspot in the field of regenerative repair in recent years. However, for large-area wounds, local injection often leads to low cell retention and survival rates. As the only natural alkaline polysaccharide in nature, chitosan (CS) materials are widely sourced, have low toxicity, and possess good biodegradability and biocompatibility. Chitosan-based nanofiber membranes, resembling the characteristics of the extracellular matrix, offer better cell adhesion, biocompatibility, and antibacterial properties, and are widely used as carriers for stem cells to enhance their therapeutic efficacy. To overcome the drawbacks of chitosan nanofiber mats—irregular pores and poor stem-cell loading—the study introduces a 4-D-bioprinted chitosan carrier (4D-CTH) whose uniform, programmable pores collapse and recover on demand, doubling loading efficiency and boosting repair. Compared to traditional 3D bioprinting, nanofiber membranes prepared by 4D bioprinting technology can not only be stimulated by various external factors such as temperature, light intensity, pH, and ion concentration to undergo shape or function regulation but can also achieve dynamically changing and hierarchically complex structures through temporal and spatial control. 3D bioprinted nanofiber membranes possess certain mechanical support properties, better aligning with the dynamic nature of organisms. Employing the 3D-CTH nanofiber scaffold to accommodate rabbit adipose-derived mesenchymal stem cells (ADSCs) is expected to elevate both seeding efficiency and cell viability, thereby amplifying the reparative potency of ADSCs and offering an innovative modality for cutaneous-wound healing.