title: Microencapsulation of maltogenic α-amylase in poly(urethane-urea) shell: inverse emulsion method.
abstract: The novel poly(urethane-urea) microcapsules (PUUMC) were obtained by the interfacial polyaddition reaction between the oil-soluble hexamethylene diisocyanate (HMDI) and the water soluble poly(vinyl alcohol) (PVA) in a water-in-oil (W/O) emulsion. The PVA was used instead of diols. Maltogenase L (maltogenic α-amylase from Bacillus stearothermophilus (E. C. 3.2.1.133) (MG) was encapsulated in the PUUMC during or after formation of capsules. The PUUMC were thoroughly characterised by chemical analytical methods, FT-IR, SEM, thermal analysis, surface area, pore volume and size analysis. Furthermore, by carefully analysing the influencing factors including: catalyst and surfactants and their concentrations, the initial molar ratio of PVA and HMDI, stirring rate and ratio of dispersed phase to external phase, the optimum synthesis conditions were found out. A controlled release of MG could be observed in many cases. Delayed-release capsules were obtained when initial concentration of HMDI was increased. These capsules have potential application in biotechnology for saccharification of starch.
authors.affiliation: a Department of Polymer Chemistry , Vilnius University , Vilnius , Lithuania.
authors.forename: Sandra
authors.initials: S
authors.lastname: Maciulyte
authors.forename: Tatjana
authors.initials: T
authors.lastname: Kochane
authors.forename: Saulute
authors.initials: S
authors.lastname: Budriene
mesh_terms: D002214:Capsules; D002623:Chemistry Techniques, Analytical; D003692:Delayed-Action Preparations; D004339:Drug Compounding; D004655:Emulsions; D005612:Freeze Drying; D001411:Geobacillus stearothermophilus; D006358:Hot Temperature; D008320:Maltose / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011140:Polyurethanes / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry; D013499:Surface Properties; D013818:Thermogravimetry; D014508:Urea / Q000737:chemistry*; D014520:Urethane / Q000737:chemistry; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D004655:Emulsions; D011140:Polyurethanes; D014520:Urethane; D008320:Maltose; D014508:Urea; D011142:Polyvinyl Alcohol; D013213:Starch; D000516:alpha-Amylases
keywords: Poly(urethane–urea); controlled-release; emulsion; microencapsulation; poly(vinyl alcohol); porosity