Preparation And Application Of Hydrogel Microspheres Based On Step Emulsification Microfluidics

Hydrogel microparticles have widely applications in drug delivery,cell culture,biosensing,etc.,due to their good biocompatibility,large specific surface area,and high flexibility.Hydrogel microparticles could be used as microcarriers,which ccould safely and effectively encapsulate and deliver active ingredients such as drugs and cells.Based on microparticles degradation characteristics and porous structure,active ingredients could be effective release to achieve the disease treatment.At present,various techniques have been used for the preparation of hydrogel microparticles,a popular technique is droplet microfluidics.The monodisperse droplet template was prepared by drolet microfluidics,and the microparticles are prepared after droplets curing.The precise control of microfluidic technology in the emulsification process can achieve uniform loading of active ingredients and ensure the monodispersity of the microparticles.However,current microfluidic platforms are difficult to achieve high-throughput production of microparticles,and it is difficult to meet the demand for a large number of hydrogel microparticles in practical applications.The step emulsification microfluidic technology can provide high-throughput,monodisperse emulsion droplets during the emulsification process,which provides an effective strategy for the high-throughput preparation of hydrogel microparticles.Based on the step emulsification microfluidic platform,we provided a solution for high-throughput production of biomedical hydrogel microparticles.The active ingredients could be encapsulated during the emulsification process,and the photothermal response of hydrogel microparticles,drug delivery,cell culture and other applications are realized.Specific work include the following:(1)Preparation and characterization of step emulsification microfluidic chip: The step emulsification channel was designed and the step emulsification PDMS-glass chip was prepared by soft lithography.The hydrophobic treatment of chip microchannels enables the chip to be used to prepare droplet templates for hydrogel precursors.The droplet formation process was observed by a high-speed camera,the shape and size of the droplets were recorded by an optical microscope,and the robust performance of the chip was characterized by adjusting the flow rate,running time,and dispersed phase concentration.(2)Preparation and characterization of BP/GelMA hydrogel microparticles: The photocrosslinkable GelMA hydrogel was obtained by modifying gelatin,and the black phosphorus nanosheets and GelMA hydrogel were used as the dispersed phase liquid,and the step emulsification was carried out.Droplets were formed and solidified under UV irradiation to form BP/GelMA hydrogel microparticles.Characterize the morphology of the microparticlesunder light and electron microscopes,and explore the photothermal responsiveness of the microparticles under the near-infrared.(3)Biomedical application of GelMA hydrogel microparticles: macromolecular drugs and small molecular drugs were encapsulated in BP/GelMA microparticles by step emulsification technology,and the controllable release of drugs under near-infrared irradiation was analyzed.The anticancer drug DOX was encapsulated in the microparticles,and the DOX-loaded microparticles were co-cultured with Hep G2 tumor cells to explore its killing effect on tumor cells in vitro.The biocompatibility of GelMA microparticles and the ability to support cell adhesion and proliferation were demonstrated.