Polycaprolactone (PCL) and polylactide (PLA) are two of the most well-known biodegradable polymers but despite being discovered nearly a century ago, their use in applications has been limited. More recently, interest in these so-called “forgotten” biodegradable polymers has reemerged particularly towards use in biomedical applications such as tissue engineering (TE). Current challenges include elucidating structure-functions property relationships to fine-tune material construct properties and implementing appropriate material characterization techniques. Herein, the properties of bone TE scaffolds based on chemically cross-linked PCL with shape memory polymer (SMP) behavior were tailored via macromolecular design. First, various PLA-based thermoplastic polymers were combined with the PCL network affording PCL/PLA semi-interpenetrating networks (semi-IPNs) with customizable degradation profiles and improved mechanical properties. Hydrolytic degradation was also studied under both base-catalyzed and neutral, more physiologically relevant, conditions. Next, 4-arm star PCL and PLA were substituted into the PCL/PLA semi-IPN scaffolds to optimize SMP behavior via lowering PCLs melting temperature for improved implantation techniques. Lastly, compatibilized poly(propylene fumarate) (PPF) block copolymers were incorporated with the PCL network to form PCL/PPF co-networks with tunable hydration. Notably these hydrogel-like macroporous scaffolds were shown to maintain relatively high mechanical properties (E &gt; 1 MPa and CS &gt; 4 MPa) over a 4-month in vitro degradation study demonstrating their suitability for bone TE. Throughout the aforementioned studies, the PCL-based scaffolds were prepared free of biologic agents (ie. stem cells, growth factors) to lower cost and streamline production while also circumventing convoluted regulatory hurdles associated with such additives. Analogous polymeric material design approaches may be further employed to improve the utility and accessibility of common biodegradable polymers like PCL and PLA in a wide array of biomedical applications.

Tailoring biodegradable polymer materials towards innovative biomedical applications

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.