Evaluation of the Effects of Biodegradable Microspheres Loaded with Quercetin on Adipogenic and Chondrogenic Differentiation of Cellular Spheroids

This study was performed to evaluate the effects of quercetin application and the biodegradable poly(lactic-co-glycolic acid)-based microspheres loaded with quercetin on the adipogenic and chondrogenic differentiation of three-dimensional cells composed of gingiva-derived stem cells and osteoblast-like cells. Three-dimensional cell spheroids were fabricated using silicon elastomer-based concave microwells and cultured in adipogenic and chondrogenic media. Quercetin at 1 μg/mL (Q1) and microspheres loaded with quercetin at 1 μg/mL (M1) were used. Quantitative cellular viability was evaluated using Cell Counting Kit-8 assay. Adipogenesis was determined after oil red O staining and chondrogensis was evaluated by measuring relative intensity of Alcian blue staining. Spheroids were well maintained irrespective of quercetin application in silicon elastomer-based concave microwells. The relative Cell Counting Kit-8 assay values for unloaded, Q1, and M1 groups in adipogenic media on Day 1 were 100.0±7.6%, 153.6±11.3%, and 104.7±6.3%, respectively. Relative values of adipogenesis were 114.6%, 116.2%, and 113.4% for unloaded, Q1, and M1 groups on Day 7, respectively, and relative values of adipogenesis were 131.7%, 137.5%, and 133.6% for unloaded, Q1, and M1 groups on Day 14, respectively. The relative Cell Counting Kit-8 assay values for unloaded, Q1, and M1 groups in chondrogenic media on Day 1 were 100.0±3.2%, 162.1±13.0%, and 96.6±3.7%, respectively. Relative values of chondrogensis were 103.6%, 111.0%, and 103.7% for unloaded, Q1, and M1 groups on Day 7, respectively, and the relative values of chondrogensis were 157.4%, 165.3%, and 160.9% for unloaded, Q1, and M1 groups on Day 14, respectively. Application of quercetin produced quercetin at 1 μg/mL and promoted the viability of cell spheroids cultured in adipogenic and chondrogenic media. However, application of quercetin did not reach statistically significant enhancement of adipogenisis or chondrogenesis at the experimental condition.