Synthesis of PDLA–co–TEHA Copolymer Patches for Skin Injury Treatment

Skin injuries are encountered by millions of patients globally. They are caused by burns, chronic ulcers of different causes, infections, cancer surgery, and other diseases, and require effective treatment to prevent morbidity or mortality. Various patches, with different properties to restore the function of the skin after damage and to facilitate wound healing have been created.

This work concerns the production of a patch with prolonged action based on poly (d-lactic acid) (PDLA) with thioether-containing ω-hydroxyacid (TEHA). PLA is an aliphatic polyester derived from lactic acid, that stands out in a wide range of medical applications, because of its biocompatibility and renewability, and excellent mechanical, thermal and processing properties. It is available at a low cost compared to other common biodegradable polymeric biomaterials. However, the in vivo hydrolysis rate of PLA is very slow. For this reason, block copolymers of TEHA and PDLA (TEHA-co-PDLA) were prepared in various ratios in order to slowly release active substances topically on the skin.

The physicochemical properties of the prepared copolymer were examined with FTIR, DSC and XRD. From 1H NMR and FTIR the successful synthesis of the materials was confirmed. XRD measurements revealed the amorphous form of TEHA-co-PDLA copolymers. DSC was used to be studied the thermal properties of the materials.