Clinical, Cosmetic and Investigational Dermatology (Sep 2020)
Effect of Hyaluronic Acid and Poly-L-Lactic Acid Dermal Fillers on Collagen Synthesis: An in vitro and in vivo Study
Abstract
Larissa Rocha Bertelli Cabral,1 Lucas Novaes Teixeira,1 Rodrigo Pinto Gimenez,2 Ana Paula Dias Demasi,1 Rui Barbosa de Brito Junior,1 Vera Cavalcanti de Araújo,1 Elizabeth Ferreira Martinez1 1Division of Cell Biology and Oral Pathology, Faculdade São Leopoldo Mandic, Campinas, São Paulo, Brazil; 2Division of Plastic Surgery, Faculdade São Leopoldo Mandic, Campinas, São Paulo, BrazilCorrespondence: Elizabeth Ferreira MartinezDivision of Cell Biology and Oral Pathology, Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira, 13, Campinas CEP 13045-755, São Paulo, BrazilTel/Fax +55 19 3211 3600Email [email protected]: Skin ageing is marked by structural and functional changes in epidermis and dermis, which result clinically in wrinkles, loss of elasticity, and rough-textured appearance. In this context, different dermal fillers have been used to overcome these negative effects associated with skin ageing, such as hyaluronic acid (HA) and poly-L-lactic acid (PLLA). Despite their low immunogenicity, these materials can cause an inflammatory reaction after application.Materials and Methods: Considering high demand of HA and PLLA as filler material, this study aimed to evaluate their in vitro and in vivo effects. For the in vitro study, human dermal fibroblast cell cultures were supplemented with HA or PLLA for 24, 48, and 72 h. The following parameters were assayed: 1) cell proliferation, 2) cell viability, and 3) quantification of type I collagen by ELISA. For the in vivo study, HA or PLLA was injected in the dermis of Wistar rats and the tissues were collected after 15, 30, and 60 days for histologic evaluation and for quantification of type I collagen by Western blotting. The quantitative data were statistically analyzed using an ANOVA two-way. The significance level was set at 5%.Results: At 72 h, high cell proliferation was observed for HA compared to control (p< 0.05). Cultures exposed to PLLA exhibited a reduction in both cell proliferation and viability compared to control in all time points (p< 0.05). Type I collagen expression was greater in cultures exposed to HA or PLLA compared to control (p< 0.05). Histologic analysis showed the presence of multinucleated cells only in the PLLA group in all experimental time points. Western blotting analysis revealed high content of type I collagen in HA compared to PLLA (p< 0.05).Conclusion: The present study addresses a potentially unfavorable effect of dermal PLLA filler on the fibroblast phenotype, with possible clinical complications, unlike HA.Keywords: cell culture, extracellular matrix, ageing, skin
