Preparation,Modification And Release Of Enzyme Microcapsule

At present,people have been advocating health care and environmental protection.The immobilized enzyme has the advantages of reproducibility,low toxicity and specific catalysis,so it has become the hot spot of current research.As usual enzyme production,the free enzymes activity is easily restricted by various environmental factors,and immobilization of enzymes can reduce the impact of the environmental factors on enzymes,to maintain good catalytic activity as in production and use.In this study,the free enzyme was fixed by microencapsulation(solvent volatilization method)and its release property was tested.The main research contents are as follows:The microcapsules were prepared with gelatin-Arabic gum as wall material,alpha-amylase as core material and glutaraldehyde as crosslinking agent.The dispersibility and morphology of the microcapsules were analyzed by optical microscope(OM)and scanning electron microscope(SEM).With PCL as wall material,dichloromethane as oil phase,solid-amylase as core material,and PVA aqueous solution as water phase,microcapsules were prepared by solvent volatilization method,and analyzed by optical microscope(OM),scanning electron microscope(SEM),and thermogravimetric analysis(TG).The results show that the microcapsules formed by the compound condensation method stick together,and the embedding technology of hydrophilic core material needs to be further explored.The microcapsules formed by solvent volatilization have good dispersibility and smooth and dense surface,and the thermogravimetric analysis shows two weight loss platforms,and the microencapsulation of core materials is completed.The W₁/O/W₂ emulsion solvent evaporation method was used to prepare microcapsules by wrapping the hydrophilic macromolecule-amylase in the polymer carrier material PCL.The morphology,particle size distribution and thermal stability of the enzyme preparation microcapsules were taken as the indicators.Through the single-factor analysis and optimization of the preparation process of the microcapsules,the optimal preparation process was obtained as follows:PCL molecular weight was 50,000;the compound emulsion method was homogenizer stirring;the reaction time could be completed within 380min;Span80 content was 3%in oil;oil-water ratio(W₁:O=1:4;Under the conditions of E₁/W₂=1:8.75),3%PVA content and 30 mg/mL PCL concentration in W₂,the microcapsules were obtained with uniform particle size,round shape,smooth density and good dispersibility.The average drug load was 50.37ul/g,and the in vitro slow-release performance was as follows:the release percentage at 70?was 54.03%.Poly(caprolactone)was doped with poly(lactic acid)(doping ratio:95:5),and microcapsules were prepared with it as the wall material.XRD,TG,SEM,FTIR and DSC were used to analyze the polycaprolactone.The results showed that polycaprolactone and polylactic acid had good compatibility,no chemical reaction occurred,and the drug loading rate of microcapsules was improved by 30.3%.