“Sponge-like” dressings based on biopolymers for the delivery of platelet lysate to skin chronic wounds

Abstract

The aim of the present work was the development of sponge-like dressings, obtained by freeze-drying, based on chitosan glutamate and sodium hyaluronate for platelet lysate (PL) delivery to chronic skin wounds. A first phase of the research focused on the choice of the best dressing composition to obtain formulations endowed with the desired mechanical and hydration properties. In particular glycine amount (cryoprotectant agent), and water content were considered as formulation variables. The addition of glycerophosphate, used to solubilize chitosan at pH close to neutrality, was also investigated. In the second phase of the research, dressings were loaded with different amounts of PL. The influence of freeze-drying process and of excipients on the biological activity of platelet growth factors was investigated by means of a cell proliferation test using human fibroblasts. PDGF AB (platelet derived growth factor) content was assayed by means of ELISA test. Depending on composition, dressings showed different mechanical and hydration properties that make them suitable to wounds with different exudate amounts. Both freeze-drying process and excipients employed did not disturb the activity of platelet growth factors. The dressings loaded with platelet lysate were characterized by % proliferation values on fibroblast cell comparable to those observed for the fresh hemoderivate. The PDGF AB assay confirmed the results obtained from cell proliferation test.