A Methodologic Approach for the Selection of Bio-Resorbable Polymers in the Development of Medical Devices: The Case of Poly(l-lactide-co-ε-caprolactone).

Alberto Cingolani,Filippo Rossi,Giuseppe Perale,Stefano Caimi,Mattia Sponchioni,Antoine Klaue,Tommaso Casalini

doi:10.3390/polym10080851

Abstract

In the last decades bioresorbable and biodegradable polymers have gained a very good reputation both in research and in industry thanks to their unique characteristics. They are able to ensure high performance and biocompatibility, at the same time avoiding post-healing surgical interventions for device removal. In the medical device industry, it is widely known that product formulation and manufacturing need to follow specific procedures in order to ensure both the proper mechanical properties and desired degradation profile. Moreover, the sterilization method is crucial and its impact on physical properties is generally underestimated. In this work we focused our attention on the effect of different terminal sterilization methods on two commercially available poly(l-lactide-co-ε-caprolactone) with equivalent chemical composition (70% PLA and 30% PCL) and relatively similar initial molecular weights, but different chain arrangements and crystallinity. Results obtained show that crystallinity plays a key role in helping preserve the narrow distribution of chains and, as a consequence, defined physical properties. These statements can be used as guidelines for a better choice of the most adequate biodegradable polymers in the production of resorbable medical devices.

Highlights

Biodegradable polymers have become, in the last decade, a major base material for the development of many different bioresorbable medical devices [1,2,3]
We identified two major points to be taken into consideration in the formulation of polymer-based medical devices: first, the importance of establishing the impact of the selected terminal sterilization methodology on the polymeric material itself; second, the characterization of the base polymer cannot focus on the molecular weight and chemical composition but needs to be extended to other physical parameters
All sterilization protocols involved in this work have been conducted in accordance to the aforementioned requirements and are the actual ones currently in use for conventional protocols in the production of biodegradable polymer-based medical devices

Summary

Introduction

Biodegradable polymers have become, in the last decade, a major base material for the development of many different bioresorbable medical devices [1,2,3]. Playing with the initial composition of polymers and their molecular weights, mostly derivatives of polylactic acid (PLA), of polyglycolic acid (PGA) and of polycaprolactone (PCL), and/or their copolymers and blends, enables them to perfectly combine desired mechanical characteristics with a fully bioresorbable product [7,8]. They properly address the big disadvantage of the post-healing surgical intervention for devices that need to be implanted into the patient’s body [9], because, upon degradation, they will be naturally eliminated by the organism without necessity of direct removal [10,11,12]. The great advantage that all of the aforementioned products have in common is that they will naturally disappear from the patient’s body in reasonable and controllable time after the implantation, leaving minimal traces and small impact [1]

Methods

Results

Conclusion