Revolutionary tubular scaffolds boost stem cell-driven bone regeneration in skull defects

Scientists from Sun Yat-sen University's School of Biomedical Engineering have developed groundbreaking tubular scaffolds made from electrospun membranes, which significantly enhance bone regeneration in critical skull defects. These scaffolds, designed to mimic natural bone structures, create an ideal environment for adipose-derived stem cells (rADSCs) to thrive and accelerate healing. By integrating advanced materials like polycaprolactone, PLGA, and nano-hydroxyapatite, the researchers achieved remarkable results in both lab and animal studies, paving the way for innovative treatments in bone defect repair. This study marks a major leap forward in tissue engineering and regenerative medicine.

Critical-sized bone defects pose a significant challenge in the medical field. Traditional treatments using autografts and allografts are limited by donor scarcity, size mismatches between grafts and defect areas, and immune rejection, hindering widespread application. Bone tissue engineering offers a new solution by combining cells with biomaterials. Adipose-derived stem cells (ADSCs) have gained attentions in bone regeneration research due to their easy accessibility and strong osteogenic differentiation potential. However, direct injection of ADSCs results in short survival time, whereas combining them with scaffold materials significantly enhances in vivo retention and bone regeneration performance. Current research employs techniques such as electrospinning and 3D printing to fabricate scaffolds that mimic bone, substantially promoting bone regeneration. Integrating chemical signals like growth factors with the physical properties of scaffolds can further enhance the osteogenic differentiation of ADSCs. Despite these advances, limitations still exist in mimicking the hierarchical structure of bone, necessitating further optimization of scaffold design and combination strategies to improve clinical outcomes in bone regeneration.

The Solution: Researchers from School of Biomedical Engineering at Sun Yat-sen University have developed multilayer composite nanofibrous membranes containing polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and nano-hydroxyapatite (HAp) using electrospinning technology. Under conditions where the bilayer thickness ratio was 1:2 and the initial total thickness was 2.5 μm, BLCMs could spontaneously deform into 3D scaffolds under certain incubation conditions after being cut into structural units of specific shapes. These scaffolds effectively simulate bone and provide a suitable microenvironment for rADSCs to promote bone regeneration.

The Future: The constructed materials exhibit excellent capabilities in promoting rADSC proliferation and osteogenic differentiation, demonstrating significant potential for bone regeneration. Notably, the tubular units enhanced the effects of rADSCs on bone regeneration, and the potential relations of VEGF, BMP-2, and the 3D fibrous structure on promoting osteogenesis of rADSCs were clarified in this study. Future research should further investigate the fabrication of fibrous membrane scaffolds and the mechanism of the loaded MSCs on bone regeneration.

The Impact: This study developed multilayer composite nanofibrous tubular scaffolds using electrospinning technology, which effectively mimic bone structures and provide an optimal microenvironment for rADSCs to promote bone regeneration. Both in vitro and in vivo experimental results indicate that the constructed fibrous membranes hold significant potential for treating bone defects, offering a promising approach for bone regeneration.

This work has been recently published in the online edition of Materials Futures, a prominent international journal in the field of interdisciplinary materials science research.

Reference:
Huamin Jiang, Zhaoyi Lin, Jinze Li, Ting Song, Hongyun Zang, Pengwen Li, Jiarun Li, Wenyi Hou, Jianhua Zhou, and Yan Li, “rADSC-loaded tubular units composed of multilayer electrospun membranes promoted bone regeneration of critical-sized skull defects” 2024, DOI: 10.1088/2752-5724/ad66ea