Visualizing the Inner Architecture of Poly(ϵ-caprolactone)-Based Biomaterials and Its Impact on Performance Optimization.

The performance of poly(ϵ-caprolactone) (PCL)-based biomaterials is defined by spatial distributions of PCL's amorphous and crystalline domains. Unfortunately, directly visualizing their inner architectures has been challenging. This study demonstrates, the superior degradation selectivity of Candida antarctica lipase B (CALB) enzyme; when used at low concentrations, it preferentially breaks down the amorphous chains prior to the crystalline chains. Top-down dissection using this enzyme is performed on several PCL-based systems. Self-assembled nanolamellae (e.g., thin films) or hierarchically nanostructured crystalline skeletons (e.g., fibers) are clearly captured. Thus, the spatial distribution of the amorphous compartments can be precisely mapped out, which otherwise cannot be achieved.