Fabrication Of Inverse Opal Hydrogel Microcarriers And Their Applications In Biological Analysis

With the rapid development of bioscience related industries, a large number of new biomedical products appeared, in order to study the function of each component and their interaction in biological systems, efficient and feasible bioanalytical techniques is indispensable. Bioassay is not only an essential tool for the investigation of bioscience, but also required by regulatory authorities in setting product specifications. In addition to the established fluorescence, electrochemistry and enzymatic amplification technology, newly developed materials, such as nanoparticles, nanowires, and photonic crystals (PCs), have also shown great promise in bioassays. Among these, inverse opal photonic crystals have attracted increasing interests in this field, because of its wonderful characteristic including stability of coding information, easier adjusting of material refractive index, three dimensional interconnected pore system, lower bending and larger specific surface area. However, most of the developed inverse opal materials could only implement simple multivariate biological molecular detection, or cell culture on the surface and internal macropores, while their applications in controlled release of bioactive molecular and bioassays at cell level remains to be explored. Thus there is still great chanllenge to prepare multifunctional and extensive inverse opal materials which are suitable for biomedical assays. Herein, we chose stimuli-responsive hydrogel as framework material to fabricate several kinds of inverse opal microcarriers with different function by template relication technology, and investigated their applications in controlled drug release and cell evaluating. The detailed content of the work are as follows:(1) Fabrication of inverse opal hydrogel microcarriers:perapared glass capillary micofluidic devices to fabricate photonic crystal particles with uniform size and high monodispersity. Then the photenic crystal particles were used as template to produce inverse opal microcarrier and core-shell inverse opal microcarrier by completely and partly removing the slilica template, respectively.(2) Inverse opal hydrogel microcarrier for drug delivery and monitor:the thermo-responsive inverse opal microcarrier was composed of N-isopropylacrylamide (NIPAM) hydrogel. Since the shrink and swell of the microcarrier under different temperature triggers, the encapsulated drug could be extruede from the nanopores of the particle. Therefore, this release can be controlled by adjusting the temperature. With release of the drugs, the characteristic reflection peak of the inverse opal particles blue shifted correspondingly. Thus, the process of drug release from the particles could be monitored in real time.(3) Inverse opal hydrogel microcarrier for the capture and detection of blood cells: we present a new type of suspension array that can simultaneously capture and detect multiple types of blood cells. The barcode particles are polyacrylamide (PAAm) hydrogel inverse opal microcarriers with characteristic reflection peak codes that remain stable during cell capture on their surfaces. The hydrophilic PAAm hydrogel scaffolds of the barcode particles can entrap various plasma proteins to capture different cells in the blood.