Polyvinyl Alcohol/Lithospermum Erythrorhizon Nanofibrous Membrane: Characterizations, In Vitro Drug Release, and Cell Viability

This study proposes an optimization process of the Lithospermum erythrorhizon (LE) extraction with a higher purity of shikonin (SK). The influence of extraction temperature on the concentration of SK is examined, and an in vitro cell viability assay is used to examine the optimal concentration of SK. Afterwards, polyvinyl alcohol (PVA)/LE solutions at ratios of 90/10, 80/20, and 70/30 w/w are electrospun into LE electrospun nanofibrous membranes (LENMs). The optimal manufacture parameters of LENMs are evaluated based on the test results of in vitro drug release test and cell viability assay. The optimal concentration occurs when the extraction temperature is -10 degrees C. The purity of the LE extract reaches 53.8% and the concentration of SK is 1.07 mg/mL. Moreover, the cell viability of nanofibrous membranes significantly increases to 136.8% when 0.7 M SK is used. The diameter of nanofibers of LENM is decreased by 43.9% when the ratio of PVA solution to LE extract is 70/30 (w/w). 80/20 (w/w) LENM has the maximum amount of drug release of 79% for a continuous period of 48 h. In particular, 90/10 (w/w) LENM can create the maximum cell proliferation of 157.5% in a 24-h in vitro cell viability assay. This suggests that LENM has great potential to be used in facilitating tissue regeneration and wound healing.