Poly ( lactide - co - glycolide ) microspheres and hydrogel delivery systems for soft tissue and cartilage tissue engineering applications

Аннотация

Polymeric microspheres have been widely investigated as delivery systems and are clinically used today. We examined the use of poly(lactide-co-glycolide) (PLGA) microspheres in delivery systems for soft tissue engineering, chemotherapeutic delivery, and cartilage tissue engineering. Soft tissue defects due to trauma or tumor removal remain a clinical challenge. We examined the use of PLGA microspheres and adipose derived stem cells (ASCs) to fill in soft tissue defects. We first demonstrated the use of PLGA microspheres to increase ASC proliferation and survival by encapsulating fibroblast growth factor-2 (FGF-2). The released FGF-2 increased ASC proliferation and survival in vitro. Addition of the FGF-2 microspheres in an in vivo study resulted in an increase in angiogenesis. We then examined the ability of released adipogenic factors to induce the differentiation of ASCs into mature adipocytes. Oil red O staining and Western blots confirmed that adipogenesis was induced by the released factors. The second goal was to examine a delivery system to reduce the risk of local recurrence in breast cancer patients following a lumpectomy. Breast cancer lumps are commonly treated by tumor removal (lumpectomy) followed by radiation or chemotherapy, and both have adverse side effects. PLGA microspheres encapsulating doxorubicin were embedded with a natural scaffold, gelatin, to locally deliver chemotherapy and maintain the breast contour