Microfluidics Fabrication Of Multiple Microcapsules For Drug Release Applications

Cancer is a serious disease that harms human health and cancer cells usually have a primary drug resistance.Currently,chemotherapy drugs used in the treatment of cancer is very limit,the single chemotherapy drug treatment effect is poor.Combining two or more than two drugs is an effective anticancer method.But high frequency of medication for a long time will bring a series of side effects,preparing sustained release drug is very necessary.Microencapsulation technology uses a polymer shell to encapsulate drugs or stabilize the inner materials.It has been wildly used in medicine,life science,paints,household chemicals,foods,adhesive substance and so on.The key points of multifunctional microcapsules are the sizes,inner structures and monodispersity can be controlled precisely.There are some reports about monodisperse multi-emulsions,but it is still difficult to control the size and structure simultaneously.The traditional methods couldn't efficiently produce microcapsules with high qualities to satisfy the practical demands on the sphericity,concentricity and monodispersity of the microcapsules.Microfluidic is a technology to precisely control submicron scale fluids and could generate highly monodispersed emulsion droplets efficiently with high degree of control on size and shell thickness.Microfluidics chips are miniaturized,integrated and flexible 'Micro Total Analysis System'.It is possible to prepare functional materials with different inner structure,such as multi-dispersed emulsion can be prepared and the number and size of each layer droplets can be precisely controlled.The microchannel emulsification device based on microfluidic technique has remarkable advantages:the sizes of monodisperse droplets are well controlled;the size of droplets is small,the diameter is from nano-scale to micron scale;different samples with different characters can be encapsulated in;more complex droplets can be prepared by extending the device.Herein,we use microfluidics to fabricate double and triple microcapsules with different structures and applications,can be used for drug release,the detailed works are as following:(1)Fabricating double and triple microcapsules based on microfluidics:Design and construct glass capillary microfluidic chips used for generating double and triple emulsions,respectively.(2)Fabricating double microcapsules encapsulated with anticancer drugs:Using double emulsion as templates,encapsulating anticancer drugs in the microcapsules,solidifying the template and achieving double microcapsules trapped with drugs;the microcapsules were characterized by optical microscope,fluorescence microscope,laser confocal microscopy and electron microscope and so on.The drug content and encapsulation efficiency were also detected.(3)In vitro drug release and the treatment:In vitro drug release behavior and the treatment for cancer cells were studied.MTT assay demonstrated that the microcapsules without drugs shows non-toxic,two drugs co-delivery shows synergistic effect to cancer cells.