The small volume subcutaneous polyalkylimide injection-induced collagen capsule in rats: A preliminary study

Abstract

Background: Polyalkylimide is a permanent dermal filler that has been used for skin augmentation to ameliorate skin ageing. The massive volume injection has a higher risk of complication. This study aims to find collagen capsule formation by small volume polyalkylimide implantation.  Methods: We used an experimental post-test only control group design. The control group received subcutaneous NaCl injection, and the treatment group received subcutaneous polyalkylimide injection 0.018 mL (equal 1 mL in the humans). After five weeks, all rats (Rattus norvegicus) strain Wistar were sacrificed. The skin samples were collected and proceed for histologic staining. Capsule thickness was performed as mean ± SD.     Results: The treatment group showed polyalkylimide mass in subcutaneous tissue, collagen fibres surrounding the polyalkylimide, and no inflammatory cells. The collagen capsule thickness was 7.45 ± 0.78 µm.Conclusion: The small volume polyalkylimide subcutaneous injection-induced collagen capsule formation. The small volume implantation shows promising effects for skin augmentation.