Kolesnyk I. pH-sensitive hydrogel microcapsules based on polysaccharides

The thesis is devoted to development of pH-sensitive microcapsules based on the sodium alginate and its mixtures with polysaccharides of different structure to study the effect of the polymer composition on the microcapsules properties and release kinetics of protein. The influence of the main parameters (concentration of the crosslinking agent, the components ratio of the polymer mixture and its concentration, the nature and molecular weight of polysaccharides) on the efficiency of formation thin porous microcapsules with improved pH sensitivity and narrow size distribution obtained by microemulsion, extrusion and "layer-by-layer" methods was established. Optimal conditions of sodium alginate modifying with L-glutamic and L-aspartic acids (the ratio of aminoacids to polysaccharide, duration of modification, concentration of peptide bond activator) were investigated. It is shown that the microcapsules obtained of modified polysaccharide, have high encapsulation efficiency and a high degree of total protein release.