Astragaloside-loaded PCL microspheres prepared from microchips for promoting collagen regenerating

Polycaprolactone (PCL) microspheres are effective in stimulating collagen regeneration. However, the local inflammation they induce upon subcutaneous injection, particularly during the initial post-injection phase, cannot be overlooked. In this study, we designed and fabricated Astragaloside (AS)-loaded PCL microspheres using microfluidic technology for subcutaneous injection to promote collagen regeneration. The incorporation of AS and the application of microfluidic technology endowed the AS/PCL microspheres with a significantly reduced incidence of initial inflammation, thereby enhancing their safety profile. We prepared the AS/PCL microspheres <i>via</i> microfluidic technology and conducted characterization alongside <i>in vitro</i> and <i>in vivo</i> studies. Results demonstrated that the AS/PCL microspheres exhibited a circularity index of 0.90 ± 0.03, an average particle size of 30.45 ± 5.49 μm, and the polydispersity index (PDI) was 0.26 ± 0.03. The AS/PCL microspheres significantly enhanced the proliferation and migration of L929 fibroblasts. <i>In vivo</i> pharmacodynamic studies revealed that the inclusion of AS effectively mitigated the initial inflammatory response triggered by PCL microspheres and promoted superior collagen regeneration. Consequently, the microfluidically fabricated AS/PCL microspheres developed in this study demonstrate enhanced safety and efficacy for subcutaneous injection in promoting collagen regeneration.