摘要

Objectives: Numerous dermatological treatments aim to promote skin rejuvenation. In this context, hyaluronic acid is highly used, as it represents a biocompatible molecule with a low potential for hypersensitivity. Its function as a filler and volumizer is well-known in clinical practice and the extant literature. Nevertheless, few biopsy studies have demonstrated its action as an extracellular matrix remodeller and stimulator of collagen production; which led us to evaluate these effects in a study comprising intradermal application of cohesive polydensified matrix (CPM) hyaluronic acid through biopsies. Introduction: The skin is the largest human organ and comprises three main layers, epidermis, dermis and hypodermis; each with specific characteristics and functions. The dermis is formed by connective tissue rich in extracellular matrix, composed of glycosaminoglycans such as hyaluronic acid, collagen and elastic fibers, providing resistance and elasticity. During aging, skin's biomechanical properties are lost, which include gradual loss of fiber network, resulting in sagging. Hyaluronic acid is largely used for anti-ageing purposes. Despite this, its mechanisms and features have not been fully explained. Materials / method: Considering the impact of hormonal variations on the dermis, particularly in women during chronological aging; we decided to study four women, each representing a distinct age group from thirty-five to sixty age years. The patients were submitted to skin biopsies of the arm region at zero, three and six months after superficial application of CPM hyaluronic acid in a 2 x 2cm area. Then, the samples were evaluated for histological, immunohistochemical and biochemical analyses (hyaluronic acid dosage by ELISA). In addition, the patients underwent to skin ultrasound exams one year post-treatment. Results: Histological analyses included H&E to assess inflammation and neovascularization; as well as Masson's trichrome and picrosirius staining, which demonstrated augmentation in elastic fibres and an increase in type III collagen in 3 out of 4 patients post-treatment (confirmed by Immunohistochemistry). Furthermore, the results evience a notable elevation in the synthesis of hyaluronic acid post-application at 6 months, in comparison to 3 month. After 12 months, ultrasound corroborates the thickening of the treated area in all patients. These findings suggest remodelling and redensification of ECM. Conclusion: In the present study, we concluded the efficacy of intradermal injection of CPM hyaluronic acid as a collagen stimulator, thickening the dermis and stimulating endogenous hyaluronic acid synthesis, proving such effects in 4 women (age groups from 35 to 60 years). Our results open up prospects for research that answers if the treatment may be related to increase in fibroblasts, through cell adhesion and proliferation, or even triggering cell modulation mechanisms. This offers a considerable potential for the fields of tissue engineering and regenerative medicine with regard to skin rejuvenation