Abstract 29: Biodegradable Elastomeric Polyurethane Scaffolds Mechanically Matching With Native Heart Muscle
Introduction: Biodegradable cardiac patches need to be mechanically matching with native heart muscle, in order to provide appropriate mechanical support to rapidly restore heart functions and promote tissue remodeling for myocardial infarction (MI) management. Here, we utilized chemical molecular design to develop biodegradable elastomers with low initial modulus and then process them into porous scaffolds mechanically matching with native heart muscle.
Methods and Results: We synthesized various amorphous copolymers including poly (δ-valerolactone-co-ε-caprolactone) (PVCL) and poly (ether ester) triblock copolymers with various molecular weights and poly(ethylene glycol) (PEG) molecular weights (PVCL-PEG-PVCL). The polyurethanes were then synthesized from PVCL or PVCL-PEG-PVCL as a soft segment, hexamethylene diisocyanate (HDI) as a hard segment and putrescine as a chain extender. The polyurethane products were presented as PU-PEGx-VCLy, where x and y refer to molecular weights of PEG and PVCL, respectively. Five polymers including PU-VCL2k, PU-VCL6K, PU-PEG1K-VCL1K, PU-PEG1K-VCL6K and PU-PEG2K-VCL6K were obtained. All polymers gradually degraded in phosphate buffer solution and enzyme solution. The 3T3 fibroblasts can grow and proliferate on all polymer film surface within 5 day culture, indicating the polymers have good cellular compatibility. PU-VCL6K, PU-PEG1K-VCL6K and PU-PEG2K-VCL6K were further processed into porous scaffolds using thermally induced phase separation (TIPS). The PU-PEG2K-VCL6K scaffold at wet state had 0.19 ± 0.08 MPa initial modulus, which has no significant difference from initial modulus (0.19 ± 0.04 MPa) of the native porcine heart muscle. But the tensile strength of this scaffold is lower than that of heart muscle, which requies to be improved in the future.
Conclusions: A new family of biodegradable elastic polyurethanes was synthesized and processed into porous scaffolds. The scaffolds showed promising mechanical match with heart muscle. These biodegradable polyurethane scaffolds would find opportunities to be used as a cardiac patch for heart infarction treatment.
Author Disclosures: C. Xu: 2. Research Grant; Significant; AHA BGIA support. B. Brazile: None. K. Nguyen: None. J. Liao: None. L. Tang: None. Y. Hong: 2. Research Grant; Significant; AHA BGIA Funded.
This research has received full or partial funding support from the American Heart Association, South Central Affiliate (Arkansas, New Mexico, Oklahoma & Texas).
- © 2015 by American Heart Association, Inc.