Study On Preparation And Bioactivity Of Alginate-Chisotan Microcapsules Loaded With Pig Spleen Transfer Factor

Transfer factor (TF) consisted of messenger petides and nucleotide produced by activated T lymphocytes of human and other animals. TF extracted from spleen can transfer immunity from a human to another species, and it acted in virgin lymphocytes through TF inducers, suppressors and specific antigens. It would be a complicated and lengthy transport process in vivo with slow onset and low bioavailability when TF was given by oral administration. Chisotan and sodium alginate were biodegradable natural polymers with good biocompatibility. Both of them have been widely used in drug delivery research, especially as the capsule materials for microencapsulation of protein drugs to improve the stability and controlled release of protein. In order to improve the stability of TF and reduce gastric acid and pepsin on the structure and activity of TF, We adopted healthy pig spleen as raw material using dialysis method to prepare TF extraction; TF microcapsules were prepared by emulsion external gelatification using chisotan and sodium alginate as capsule materials, the characterization and biological activity of the microcapsules were studied.TF extraction process was optimized by single-factor experimental design and orthogonal experimental design, the best available technology was:freezing and thawing the spleen homogenate9times,4℃dialysis48h with the dialysis ratio1:2. TF extraction was pale yellow liquid, slightly fishy smell, containing no giant molecule protein or bacterium, A260/A2802.82, the maximum absorption wavelength of251nm.Using encapsulation rate and appearance of the microcapsules as the main index, the praparation of TF-chisotan-alginate microcapsules was optimized by single factor experimental design and orthogonal experimental design, the best available technology was:Sodium alginate concentration of20g/L, vegetable oil and sodium alginate solution volume ratio of4:1, Span-80concentration of70g/L, calcium chloride concentration of100g/L, reaction time10min. Microcapsules were spherical, uniform particle size, encapsulation efficiency of60.8%encapsulation efficiency, drug loading11.60mg/g. Swelling capabilities of the mincrocapsules in different media and release performance in different pH buffer were investigated, the results indicated that the microcapsules posessed excellent swelling properties and release behavior. The accumlative release in vitro at pH7.4was fitted to first order kinetics equation, ln(1-Q)=-0.6691t-0.6449(R2=0.9876).TF microcapsules and TF were fed to mice to observe their effect on mice growth and index of major organs and phagocytosis by peritoneal macrophages and delayed type hypersensitivity. The results indicated that TF and TF microcapsules had no significant effect on the growth or the major organ index. Transfer factor microcapsules could potentiate the macrophage phagocytic fuction, enforce the delayed hypersensitive response and had a better therapeutic effect than transfer factor.This work successfully extracted TF and prepared TF-chisotan-alginate microcapsules, the preparing process of TF microcapsules is simple and reliable. According to its quality assessment and biological activity, TF microcapsules had good development and application prospects with lots of advantages such as increased stability, increased potency and other characteristics.