Validation Of Radiation Sterilization Dose For Proteases Immobilized On Aldehyde-Containing Textile Carriers

Abstract

The main objective of this work is to establish the parameters of radiation sterilization for three proteolytic enzymes (papain, trypsin and subtilisin) immobilized on aldehyde-containing textile carriers in terms of the development of new biomaterials – wound dressings with debridement effect. This paper describes the steps taken to validate a low dose sterilization process by following the Method 2A defined in ISO 11137. The content of aldehyde groups in the used modified cellulose carriers is 0.798  0.002 mmol/g. After immobilization and freeze-drying of the respective enzyme, all experimental variants demonstrated proteolytic activity in the following ranges: Variant 1 (immobilized papain) 47.641.73 U/g; Variant 2 (immobilized trypsin) 84.571.45 U/g; Variant 3 (immobilized subtilisin) 55.53 3.46 U/g. The obtained results for enzyme activity made it possible to determine the dose of 30 kGy as the maximum acceptable dose for all experimental variants biomaterials. The minimal doses necessary to achieve sterilization at SAL of 10 -6 are respectively: variant 1 (immobilized papain) 16.0 kGy; variant 2 (immobilized trypsin) 15.2 kGy and variant 3 (immobilized subtilisin) 12.1 kGy. These low terminal doses provide effective bactericidal coverage and very likely have minimal impact on the properties of the biomaterials. For all three variants the proteolytic activity remains above 90% of the initial value.