Study On Properties And Applications Of Fmoc-Y/Fmoc-F Peptides Based Hydrogels

Bioactive substances are a class of ingredients that have important physiological functions and health care effects on the body,including volatile oils,enzymes,probiotics,and so on.The low stability and low tolerance in gastrointestinal tract restricted the intestine absorption.Recently,microcapsule embedding technology was employed to improve the stability,but there are still some disadvantages such as low embedding rate,cumbersome process and no controlled release capability.Peptide self-assembled hydrogels have a wide application prospect in many fields such as drug delivery,tissue engineering,controlled release and food embedding because of their good biocompatibility,non-toxic,diverse configurations and good environmental responsiveness.In this work,a series of hydrogel which based on Fmoc-F/Fmoc-Y were studied.(1)Fmoc-Y/gelatin self-assembled hybrid hydrogel was prepared by Fmoc-Y molecule and gelatin.When the pH value was below 4.5,Fmoc-Y/gelatin can self-assemble to hydrogel in 37℃.The rheological results show that the mechanical properties of the hybrid hydrogel are depending on the concentration of gelatin.The results which recorded with circular dichroism(CD)indicated that formation of the hybrid hydrogel weakened the secondary structure of gelatin.Fourier transform infrared spectroscopy(FTIR)tests showed that the formation of the hydrogel was mainly due to the intermolecular hydrogen bond.Scanning electron microscopy(SEM)showed that the surface of hybrid hydrogel has a porous structure,which can embed bioactive moleculars.The results showed that when the gelatin concentration was 55%,and the ratio of Fmoc-Y to gelatin was 1/14,the lactase which was embedded with Fmoc-Y/gelatin has the highest gastric tolerance:retention rate of lactase was 85.2%which is much higher than the one of un-embedded lactase.High performance liquid chromatography(HPLC)results confirmed that with embedding by the hybrid hydrogel,lactase has the higher enzyme activity.(2)The application of Fmoc-Y/gelatin self-assembled hybrid hydrogel had been further study in intestinal probiotics.Lactobacillus bulgaricus,which is low tolerance to high temperature,strong acid and bile salt,were embedded into the Fmoc-Y/gelatin hybrid hydrogel.Incubate with the simulated gastric juice,the viability of Lactobacillus bulgaricus was 81.9%.At this condition,the concentration of gelatin was 40%,and the mass ratio of Fmoc-Y to gelatin was 1/14.After incubating in the simulated intestinal fluid,Lactobacillus bulgaricus was release from the hydrogel,and the amount was around 107 CFU/mL.(3)Self-assembled Fmoc-F peptide hydrogel were employed to embed garlic essential oil for antimicrobial.Our results demonstrated that the peptide hydrogel could prevent the volatilization and achieve the controlled-release of garlic essential oil.The loading efficiency of peptide hydrogel to garlic essential oil was 97.07%.When pH was below 5.0,the hydrogel disaggregated completely.Then the garlic oil could be released completely to inhibit the growth of E.Coli.Furthermore,the objectionable odors of garlic essential oil could be masked by the Fmoc-F based hydrogel.