Rheological and Thermal Evaluation of Polydioxanone and Bioresorbable Polymers for the Optimization of Downstream Hot Melt Extrusion

Bioresorbable polymers are of great interest to the medical sector as a means of invasive interventions, as they can be subjected to degradation in the human body. The increasing prevalence and incidence of chronic wounds is a considerable source of patient morbidity and financial burden to the healthcare system, a field where tunable biocomposites may facilitate a means of ameliorating persistent factors and warranting proximal tissue remodeling. In the development of a biopolymer medical device, there are several material considerations to note such as physicochemical, biological, and degradation profiles. Polylactic acid (PLA) and polycaprolactone (PCL) have been applied in a plethora of medical fields such as regenerative medicine, cardiovascular implants, pharmaceutical delivery, orthopedic interventions and cancer therapy. Although biocompatible, PLA and PCL have degradation profiles that can extend from months to years. In the development of medical devices, the degradation time of a biomaterial complex should coincide with the regeneration process of proximal tissue to ensure proper remodeling of the tissue. Polydioxanone (PDO) is a synthetic bioresorbable polymer with a short-term degradation profile and weak material strength that has been around since the 1980’s, yet the majority of its medical application has been as suture material. The limited supply and expensive nature of PDO are considerable factors as to why minimal research has been conducted to date. To address these limitations, independent composite formulations of PDO/PLA and PDO/PCL were produced by solvent emulsion. The physicochemical and processing characteristics of all composites were determined by FT-IR, DSC, TGA, rheology and XRD. Polymers were observed to retain their crystalline nature in FTIR and XRD analysis; however, the rheological and thermal properties of PDO were noted as tunable depending on the percent concentration of PLA / PCL respectfully.