A new insight into formation of 3D porous biomaterials

The degradation of poly( $$\varepsilon$$ -caprolactone)/poly(l-lactic acid) (PCL/PLLA) electrospun membrane was carried out in the phosphate buffer of esterase and water, respectively. A three-dimensional (3D) porous morphology was cultivated during esterase degradation, which was confirmed by scanning electronic microscope (SEM), while the structural evolution was analyzed by differential scanning calorimetry (DSC) combining with wide-angle X-ray diffraction (WAXD). Compared with hydrolysis, the degradation rate of enzymolysis was significantly faster. With the rapid decline in PCL crystallinity, the crystallinity of PLLA increased slightly after enzymolysis. The formation of porous morphology should be attributed to the relatively rapid degradation of PCL crystal and PLLA amorphous region attacked by esterase. Also, the number of micropores on the fiber surface increased with degradation time, which provides new ideas for preparing porous materials with higher porosity.