Preparation And Properties Of Pickering Emulsion Stabilized By Glucose Responsive Microgel

Pickering emulsion is a new type of emulsion consisting of aqueous phase,oil phase and solid particles with good stability,low cost,low toxicity and environmental friendliness,which is widely used in major fields.In this paper,a stable Pickering emulsion was prepared using microgels with glucose-sensitive properties as emulsifiers,and the main influencing factors of its morphology and stability were investigated and applied to the controlled release of glucose-lowering drugs.The main studies are as follows.(1)IPN-Poly(AAPBA-DMAA-co-AAm)/CS microgels with glucose-sensitive properties were prepared by interpenetrating network technology,and O/W-type Pickering emulsions were constructed using microgels as emulsifiers.FT-IR,SEM characterization and glucose sensitivity performance tests were performed on the microgels,and the results demonstrated the successful synthesis of IPN-Poly(AAPBA-DMAA-co-AAm)/CS microgels.The emulsion morphology was examined by SEM,fluorescence and particle size characterization,and the factors influencing its stability were investigated.The experimental results showed that when the CS content in the IPN-Poly(AAPBA-DMAA-co-AAm)/CS microgel was selected as 2.0wt%,the oil phase was selected as IPM,the oil-water ratio was 4:6,and the microgel content was 1.45 wt% of the aqueous phase,the prepared O/W-type Pickering emulsion was stable with an average particle size of 1245 nm.(2)GOM/Poly(AAPBA-DMAA-co-AAm)microgels with glucose-sensitive properties were prepared by free radical polymerization,and then O/W-type Pickering emulsions were constructed using the microgels as emulsifiers.The microgels were characterized by FT-IR,SEM and glucose sensitivity performance tests,and the results demonstrated that GOM/Poly(AAPBA-DMAA-co-AAm)microgels were successfully synthesized.The emulsion morphology was examined by SEM,fluorescence and particle size characterization,and the factors influencing its stability were investigated.The experimental results showed that when the GOM content of GOM/Poly(AAPBA-DMAA-co-AAm)microgel was selected to be 1.0 wt%,the oil phase was selected to be IPM,the oil-water ratio was 5:5,and the microgel content was 10.09 wt% of the aqueous phase,the best stability of the prepared O/W type Pickering emulsion was achieved with an average particle size of 688.5 nm.(3)Drug-laden Pickering emulsions with IPN-Poly(AAPBA-DMAA-co-AAm)/CS microgels and GOM/Poly(AAPBA-DMAA-co-AAm)microgels as emulsifiers were prepared using insulin as the model drug,and their in vitro drug release studies were performed.The results showed that the drug-laden Pickering emulsion stabilized by IPN-Poly(AAPBA-DMAA-co-AAm)/CS microgels almost stopped insulin release after 4 h in glucose solution when the drug delivery was 1000 μg.The cumulative release rate of insulin could reach 48.42% when the concentration of glucose was 6 m M,and 93.14% when the concentration of glucose was increased to 40 m M.GOM/Poly(AAPBA-DMAA-co-AAm)microgel-stabilized drug-laden Pickering emulsion almost stopped insulin release after 5 h in glucose solution.The cumulative release of insulin could reach 44.69% when the concentration of glucose was 6 m M,and 94.21% when the concentration of glucose was increased to 40 m M.