Fabrication Of Porous Microcarriers Based On Colloidal Crystal For Drug Release Applications

Particle-based delivery systems have received increasing attention in the area of drug research and development.Compared with the conventional administration approaches by way of long-term frequent oral administration or injections to maintain a constant drug concentration,which usually lead to the inconvenience of administration,potential overdose,and patient pain,particle-based systems can deliver drugs at the specific site to reduce systemic side effects and enhance drug delivery efficiency.These could effectively improve the bioavailability,therapeutic efficacy,and safety of the drugs and ultimately relieve the pain of patients.Among the different particle-based systems,mesporous silica nanoparticles(MSNs)have been frequently used as drug carriers because of their distinct features,such as large surface areas,strong loading capacity,steady pore volume,convenient surface functionalization,excellent biocompatibility,and so on.In addition,by attaching organic molecules “gating” at the opening pore of the NSNs,decorating the nanoparticles with polymer shells,or encapsulating them into polymer materials,stimuli-responsive drugdelivery nanosystems can be achieved for many valuable applications.However,because of the tiny size of the mesoporous channel,most of the MSNs could only load small molecular actives and need additional complex surface modifications to adsorb macromolecule actives.These limited the diversity of drug loading in the MSN-based delivery systems.Furthermore,stratagem for real-time self-monitoring of the molecule release process of the MSNs,which is essential to assess the efficiency of the delivery system,is lacking.Therefore,the development of functional mesoporous materials is expected to realize intelligent drugdelivery systems.Colloidal photonic crystals(CPCs)are a kind of three-dimensional highly ordered macroporous material,which can be quickly assembled from monodisperse nanoparticles.The periodic variety in the refractive index of the assembled materials brings about amusing optical properties,such as photonic band gaps(PBGs)and vivid structural colors,which have great prospects in the fields of biosensor,multiplex analysis,and cellular morphology.Particularly,when the CPCs are assembled by the MSNs(termed as MCPCs),they are imparted with hierarchical macro-and mesoporous structures and possess much higher specific surface area for improving their adsorption capability and thus have a considerable role in visual adsorption,gas sensing,dynamic security,and so forth.However,the potential value of the MCPCs in drug delivery remains unexplored,and their current forms of bulk films have also restricted their potential role as delivery systems.Herein,we constructed the spherical MCPCPs via self-assembly of monodisperse MSNs in microfluidic droplet templates,which can be used for drug release.The detail works are as follow:(1)Fabricating mesoporous colloidal photonic crystal particles(MCPCPs)based on microfluidics: Design and construct the microfluidic chips used for fabrication of MCPCPs with controllable size and colors.The outer and inner structures of MCPCPs were characterized by optical microscope,scanning electron microscope and transmission electron microscope.(2)Constrcting intelligent synergistic drug loading systems based on MCPCPs: Attach organic molecules “gating” at the opening pore of the NSNs to realize the controllable drug release.The macro-and micro-molecule drugs were loaded in the macro-and mesoporous of the particles respectively.The release process was also evaluated.(3)In vitro/vivo drug release and therapeutic efficacy: In vitro/vivo drug release behaviour and the effect of anticancer treatment were studied.The real-time self-monitoring of the molecule release process of the MCPCPs was also evaluated.