Study On Fabrication Of Drug-loaded Microcapsules Via The Microfluidic Monodisperse Aqueous Two Phase System Pickering Emulsion

Polyelectrolyte microcapsules have a wide range of applications in biomedicine,food,biosensing and imaging,tissue engineering and other fields.Because polyelectrolyte microcapsules have excellent encapsulation ability and response to external environmental stimuli,they have more application potential in the field of drug encapsulation and controlled release.This paper is based on the coaxial loop tube microfluidic device to generate W/W droplets,reveals the general rules of droplet size control,and stabilizes the monodisperse Aqueous two phase system Pickering emulsion by generating Calcium carbonate particles via biomimetic mineralization at the droplet interface.In addition,the monodisperse polyelectrolyte hybrid microcapsules were successfully prepared using the Aqueous two phase Pickering emulsion as a template,and its drug loading and drug release properties were explored.In the part of the construction of microfluidic Aqueous two phase droplet flow,the Dex/PEG droplet flow was successfully constructed through the coaxial loop tube microfluidic device.The droplet diameter is proportional to the first cone diameter(D_N1),internal phase pressure(P_Inner),and air pump on time(t _On),and inversely proportional to the air pump off time(t _Off).The distance between the droplets can be adjusted by the flow rate of the external phase.It is proved that urease can be locked in the Dex droplet and cannot easily diffuse into the PEG phase.The microfluidic all-water phase droplet flow system is expected to be widely used in the fields of food chemical industry,biomedicine,analysis and detection.In the part of the microfluidic preparation of the All-Aqueous Pickering emulsion,based on the microfluidic all-aqueous droplet flow system,Calcium carbonate particles are generated by biomimetic mineralization at the droplet interface,stabilizing the monodisperse all-aqueous Pickering emulsion,and the Calcium carbonate particles are positioned to grow on the droplet interface,the process is efficient.The emulsion has good monodispersity,the coefficient of variation（CV）value is about 3.3%,and the emulsion droplet diameter can be easily adjusted.And the formation of calcium carbonate particles can be controlled by the concentration of urease,calcium chloride,and urea,thereby regulating the stability of the emulsion.The maximum stability of the emulsion is 28.8 times that of the water-in-water emulsion without particle stabilization.We hope that this All-Aqueous Pickering emulsion will provide a new idea for materials preparation,drug delivery and biochemical industries.In the part of Pickering emulsion template to prepare polyelectrolyte hybrid microcapsules,monodisperse polyelectrolyte hybrid microcapsules were successfully prepared using microfluidic Aqueous two phase Pickering emulsion as a template,and its drug loading and drug release properties were explored.The average diameter（D_C）of the microcapsules is 240μm,with good monodispersity and high stability.The encapsulation rate of the model drug BSA by the microcapsule is as high as 93%.In addition,the microcapsules show good environmental responsiveness.Under acidic conditions of p H=2,when t=1.25h,89%of pepsin can be released,which shows excellent release performance that the acidic environment of the stomach is effective for large protein drugs.The polyelectrolyte hybrid microcapsules are expected to provide a new green platform for the fields of drug delivery,daily chemical industry and biocatalysis.