Comparative Evaluation of Physical Characteristics and Preclinical Data of a Novel Monodisperse Polycaprolactone Microspheres Filler.

[BACKGROUND] Demand for dermal fillers has been increasing gradually over the past decade. Polycaprolactone (PCL) fillers, a biodegradable polymer, not only naturally maintain the volume of the skin, but also stimulate collagen production by microsphere. However, inflammation can be caused by several factors such as large diameters, non-uniformity, uneven surfaces and non-spherical shapes of microspheres in use. Thus, a filler using microspheres with a uniform diameter of more than 20 μm and spherical shape was developed.

[OBJECTIVE] The main purpose of this study was to evaluate the efficacy and safety of newly monodisperse polycaprolactone microspheres fillers, IVL-F001 with smaller microsphere size and better morphology against a conventional commercial PCL filler.

[MATERIALS AND METHODS] The morphology and diameters of microsphere included in IVL-F001 and the PCL filler were analyzed, and the viscoelasticity and inject ability of both fillers were examined. After intradermal injection to hairless mice, the durability and efficacy of both fillers were evaluated through PRIMOS and Folliscope for 24 weeks. Histology was performed to assess the biocompatibility, inflammation, and collagen synthesis.

[RESULTS] Microspheres of IVL-F001 demonstrated a narrow size distribution with average diameter of 34.16 μm and distribution of 4.11. The level of injection force was low and the elasticity (G') was high compared to the licensed PCL filler. In the histopathological evaluation, IVL-F001 had significantly lower inflammatory reactions and higher collagen synthesis compared to the licensed PCL filler.

[CONCLUSION] These data indicated that IVL-F001 has lower inflammatory reaction and improved persistence compared with commercial PCL filler.

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