Investigation on the Cutaneous Change Induced by Face-Lifting Monodirectional Barbed Polydioxanone Thread

BACKGROUNDOwing to its potentially greater mechanical force on the implanted tissue, barbed thread is frequently used in face-lifting procedures. However, the long-term durability thereof remains controversial. Moreover, reports on underlying histologic and molecular changes resulting from face-lifting procedures are scarce. OBJECTIVETo evaluate histologic and molecular changes induced by absorbable, barbed face-lifting thread in an animal model. MATERIALS AND METHODSFragments of monofilament, monodirectionally barbed polydioxanone thread were implanted in dorsal skin from 12 guinea pigs. Tissue samples were harvested at 1, 3, and 7 months thereafter. Histopathologic analysis and quantification of Type 1 collagen and transforming growth factor beta 1 (TGF-β1) levels were performed. RESULTSImplantation of a single fragment induced fibrous capsule around the thread. Tissue reactions were strongest at 1 month after implantation, showing marked infiltration of inflammatory cells and fibroblasts, which gradually decreased. On molecular analysis, Type 1 collagen and TGF-β1 levels were significantly increased, compared to normal skin, throughout the 7-month study period. CONCLUSIONOur results suggest that implantation of barbed thread induces strong anchorage to skin tissue. Quantitative analysis of collagen and its downstream signaling molecule TGF-β supports the long-term durability of the thread. Therefore, the authors expect potential beneficial effect for rejuvenation on its clinical application.