Efficacy and Safety of Biodegradable Microparticles in the Regeneration of Injured Rabbit Corpus Cavernosum: Primary Report

=A bstract = Purpose: This study analyzed the effectiveness of poly (lactic-co-glycolic acid) (PLGA) as a tissue recovery agent and determines the in vivo safety and efficacy of microparticle-based PLGA. Materials and Methods: Fifteen 3-month-old male white rabbits were used. Allogenic adipose tissue derived stromal vascular fraction (SVF) was cultured and labeled with the fluorescent dye PKH26. The rabbits were divided into 4 groups: the SVF group, the PLGA group, the normal control group, and the disease control group. The right corpus cavernosal tissue of the rabbits was surgically removed in the selected portion, except in the normal control group. The defect space of each rabbit was replaced with 106 SVF cells in the SVF group and 0.1 g of biodegradable polymer solution in the PLGA group. Microscopic confirmation and analysis of tissue regeneration were performed after 8 weeks. Using confocal microscopy, the nuclei of the smooth muscle cells and SVF migration were examined. The composition of smooth muscle and fibrosis of the injured corpus cavernosum were compared and analyzed by Masson's trichrome stain. Results: There were no signs of migration or rejection of the injected materials in any of the experimental groups. The mean amount of smooth muscle in the normal control group was 15.25±1.34 μm 2 (right) and 13.90±0.703μm 2 (left); in the disease control group it was 11.10±0.87μm 2 (right) and 12.80±1.01μm 2 (left); in the SVF group it was 13.82±4.10μm 2 (right) and 13.96±3.94μm 2 (left); and in the PLGA group it was 12.89±1.39μm 2 (right) and 13.24±1.43μm 2 (left). Only the disease control group showed significant decreased smooth muscle in the left cavernosum (p 0.05). Furthermore, no difference was found between any two groups (normal control versus SVF (p=0.705), normal control versus PLGA (p=0.88), SVF versus PLGA (p=0.23). Conclusions: PLGA microparticles had the same tissue restoring effect when compared with SVF and no adverse effect or migration of particles was found through the injection of PLGA or SVF. PLGA is safe and has the proper tissue recovery effect, saving additional tissue harvesting.