title: Multilayer alginate/protamine microsized capsules: encapsulation of alpha-chymotrypsin and controlled release study.
abstract: Stable polyelectrolyte microcapsules with size 6.5 microm were produced by means of the layer-by-layer adsorption of sodium alginate and protamine to surface of melamine formaldehyde microparticles. Core decomposition at low pH leads to formation of polyelectrolyte multilayered capsules filled with alginate gel. A proteolytic enzyme, alpha-chymotrypsin, was loaded into these microcapsules by embedding in alginate gel with high efficacy. The protein in the capsules was found to retain a high physiological activity of about 70% showed with fluorescent product. The protein was found to keep inside the microcapsules in water and acid (HCl solution, pH 1.7) during 24 and 4 h, respectively, while 75-85% of protein can be revealed in supernatant after 6 h incubation at pH 8.0 (0.05 M Tris buffer) in the presence of 2.5% w/v of sodium deoxycholate. The release rate of enzyme from multilayer alginate/protamine microcapsules can be regulated by additional adsorption of polyelectrolytes onto the microcapsules with encapsulated protein. Such protein-loaded capsules can be proposed as a drug delivery system with controllable release properties.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, D-14476, Golm/Potsdam, Germany.
authors.forename: Olga P
authors.initials: OP
authors.lastname: Tiourina
authors.forename: Gleb B
authors.initials: GB
authors.lastname: Sukhorukov
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002214:Capsules; D002918:Chymotrypsin / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods*; D005079:Excipients; D018613:Microscopy, Confocal; D010316:Particle Size; D011479:Protamines / Q000737:chemistry*
chemical_list: D000464:Alginates; D002214:Capsules; D003692:Delayed-Action Preparations; D005079:Excipients; D011479:Protamines; D002918:Chymotrypsin; C117608:alpha-chymotrypsin