On-chip Construction Of Three-dimensional Cell Culture Models And Their Applications In Biomedicine

Since cells in any multicellular organisms exist in three-dimensional microenvironment including adjacent cells and extracellular matrix,it is essential to construct three-dimensional cell culture models in the fields of basic research,drug screening,tissue engineering and regenerative medicine,etc.However,the current three-dimensional cell culture models still could not meet the needs of biomedical development.In view of this situation,four kinds of on chip three-dimensional cell culture models based on new methods are proposed for drug screening and tissue engineering in this paper.The main research results are as follows:(1)A high-throughput 3D wound healing model had been constructed to study the three-dimensional growth process of cells in vitro,and based on a novel high-throughput SU-8 mesh chip,we had fabricated a novel hollow 3D cell spheroid model,which was called as 3D wound model.With the follow-up culture of the hollow cell spheroid,the cells would spontaneously grow into the 3D middle wound areas.Compared with the traditional two-dimensional wound healing model,this process was regarded as 3D wound healing process in this study,which provided a platform closer to the in vivo microenvironment for the study of cell proliferation in vitro.(2)We had developed a high-throughput angiogenesis-on-chip model based on the three-dimensional wound healing chip.The structure of SU-8 mesh chip was firstly further optimized,then human umbilical vein endothelial cells(HUVECs)were seeded on the lateral surface of each SU-8 mesh to form three-dimensional hollow cell spheroids,which were seemed as artificial vascular structures.Using these artificial vessel models,the new angiogenic sprouts had been induced in the chip,and by regulating and analyzing the sprouting process of new vessels,we had further verified the sensitivity and effectiveness of this model to drugs promoting angiogenesis.(3)We had proposed a method for constructing myocardial tissue engineering based on reduced graphene oxide foam chip.This method took nickel foam as template,and the reduced graphere oxide foam chip was obtained through the redox reaction of nickel foam and graphene oxide solution.The structure,properties and biocompatibility of the reduced graphene oxide foam chip was first tested to confirm its applicability for constructing myocardial tissues.Then through a long-term culture of primary cardiomyocytes in the foam,we had further demonstrated the potential application of the reduced graphene oxide foam chip in myocardial tissue engineering and heart-on-chip research in this chapter.(4)We had explored a method to fabricate silica-bio-composite vascular chip for 3D multi-layer vascular assembling in vitro.In this method,the in vivo 3D bifurcated vascular tissue was used as template,and the vascular chip was obtained by silica bio-replication technology based on the vascular tissue template.A layer of HUVEC cells was firstly reassembled on the surface of the vascular chip by the collagen adsorbed at the chip surface,then the vascular chip was embedded into collagen hydrogel to form new vascular network in the collagen hydrogel.In addition,we had further explored the two-layer cell assembly method based on the principle of collagen adhesion cells,which provided a simple and feasible idea for the construction of multi-layer and three-dimensional tissue structure in vitro.In summary,based on the potential applications of three-dimensional cell culture technology in drug screening and tissue engineering in vitro,this paper aims to establish new three-dimensional cell culture models with novel micochip methods,which had provided broader ideas for in vitro high-throughput drug screening and tissue engineering.