Immobilized keratinase and enrofloxacin loaded on pectin PVA cryogel patches for antimicrobial treatment

A keratinase isolated from Paecilomyces lilacinus (LPS #876) was tested against proteins present in the skin but the high enzyme activity was detected on collagen. Keratinase was physically immobilized onto PVA–pectin cryogels and enzyme release was 20.8 ± 2.1%, 63.8 ± 0.2%, 41.5 ± 3.5% and 26.0 ± 3.5% in cryogels containing pectins with esterification degrees (DE) 33.0%, 55.0%, 62.7% and 71.7% respectively at 37 °C after 3 h incubation. In presence of 0.75 M NaCl, the percentage of enzyme release changed to: 57.5 ± 1.5, 65.8 ± 3.8, 57.3 ± 0.2 and 34.0 ± 4.0 for the four pectins respectively. ro studies of enrofloxacin release from PVA–pectin cryogels at pH close to the human skin (pH = 5.5) showed 15.0% free antibiotic following first order kinetic at 37 °C after 5 h incubation. However, in the presence of keratinase only 6.9% of enrofloxacin was released under the same experimental conditions.