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 3h 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. In-vitro 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 5h incubation. However, in the presence of keratinase only 6.9% of enrofloxacin was released under the same experimental conditions.
Keywords: Controlled release; Enrofloxacin; Keratinase; PVA cryogels; Wound healing.
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