Novel Chitosan Dermal Filler with Enhanced Moldability and Elasticity

Abstract Currently, dermal fillers are largely based on commercialized cross‐linked hyaluronic acid (HA) injections, which require a large injection force. Additionally, HA can be easily decomposed by enzymes, and HA‐treated tissues present a risk of developing granuloma. In this study, a chitosan‐based dermal filler is presented that operates on a liquid‐to‐gel transition and allows the injection force to be kept ≈4.7 times lower than that required for HA injections. Evaluation of the physical properties of the chitosan filler indicates high viscoelasticity and recovery rate after gelation at 37 °C. Furthermore, in an in vivo evaluation, the liquid injection‐type chitosan filler transitions to a gel state within 5 min after injection into the body, and exhibits a compressive strength that is ≈2.4 times higher than that of cross‐linked HA. The filler also exhibits higher moldability and maintains a constant volume in the skin for a longer time than the commercial HA filler. Therefore, it is expected that the chitosan filler will be clinically applicable as a novel material for dermal tissue restoration and supplementation.