PhD Student The University of Hong Kong, Hong Kong
Abstract: In emergency situations involving the loss of hard tissues, immediate treatment is crucial. Stem cell-based approaches have shown promise for improving tissue regeneration, but current treatments lack efficacy in urgent situations due to the limited transplantation methods available for the defect. Three-dimensional (3D)-printed scaffolds have been suggested to provide structural support for damaged tissue. However, poor cell affinity and limited encapsulation techniques hinder cell inoculation and integration. To overcome these challenges, this study prepared a 3D-printed scaffold loaded with high-density stem cells from the apical papilla (SCAPs) using an injectable hydrogel composed of carboxymethyl chitosan (CMCTS) and oxidized hyaluronic acid (oHA). The SCAPs were directly encapsulated in the CMCTS/oHA hydrogel through self-crosslinking and subsequently injected into/on the 3D-printed scaffold. The hydrogel-laden scaffold exhibited excellent mechanical properties. In vitro analysis showed that the hydrogel was fully degraded, leading to the formation of 3D tissue both within and outside the scaffold. After that, when implanted in mice without prior in vitro culture, the transplants were fully fused three weeks post-implantation, achieving strong tissue integration. Interestingly, mature blood vessels were histologically confirmed and resulted from the spontaneous degradation of the hydrogel and the interaction of the transplanted cells with native host tissue. Therefore, our research reveals potential applications in musculoskeletal tissue engineering, where immediate treatment is required, making these results suitable for volumetric tissue regeneration through stem cell transplantation.
Funding Source: This work was supported by the National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (RS-2024-00405574).
