Preparation, characterization and targeted delivery of serratiopeptidase immobilized on amino-functionalized magnetic...

Targeted delivery of serratiopeptidase enzyme immobilized on magnetic nanoparticles (MNPs) of Fe3O4 has been reported for the treatment using this enzyme. The enzyme was immobilized by covalent bonding through glutaraldehyde after amino functionalization of MNPs and parameters was studied. The enzyme bound MNPs (EMNPs) were characterized for size, crystallographic identity, phase purity, zeta potential and magnetic properties along with elemental and thermal analysis. The binding of enzyme had little effect on sizes (~10-17 nm) and on magnetic properties, but the zeta potential increased from -25 mV to +14.5 mV with surface amino groups up to 350 μmoles g(-1) MNPs, to stabilize its suspensions. In the molecular level, maximum of 17 molecules of enzyme could bind to each particle of MNPs that showed residual activity 67%, decreased KM and Vmax, good storage stability. Magnetic targeting of EMNPs increased the delivery (permeation) of drug through the membrane in in vitro study and enhanced the anti-inflammatory effect on carrageenan induced paw oedema in rats in in vivo study at much lower doses of enzyme than the doses required for treatment with free enzyme.