Novel Insights in Cell Microencapsulation Technology for Mass Production of Stem Cells and Modular Tissue Formation

To provide clinically enough cell populations for different cell therapies,ex vivo mass production of stem cells should be carried out to treatpatients with different cancers and other disorders. Microencapsulationof stem cells for their mass production using hydrogels can offerseveral advantages such as the creation of defined and designed 3Dmicroenvironments to modulate stem cell phenotype, protect fromhydrodynamic forces and prevent agglomeration during cell expansion.Microcapsules can also prevent direct contact of encapsulated cells andimmune cells after in vivo implantation in the host system. Furthermore,the small size of microcapsules allows facile diffusion of nutrients, oxygen,metabolic waste, and therapeutic agents secreted by microencapsulatedcells (the ideal size of microcapsules to encapsulate cells is ~400 μm).Recently, an engineering concept called as bottom-up approach isemerging, wherein microstructure modular tissues using stem cellsare prepared first as building blocks and then assembled to fabricatemacrotissues, leading to great promise for generation of 3D constructswith no limitation in size by the assembly of modular tissues. A potentialalternative for building blocks can be microcapsules with diameters lessthan 500 μm. Many features of the micro-hydrogels such as swelling,mechanical properties, degradation, biochemical, and diffusion can bemodulated through a lot of processing conditions. Indeed, to effectivelyuse microcapsules for cell cultures, it is desirable to use tissue-specificECM with desired biomechanical and biochemical properties. In thispresentation, we will discuss novel insights concerning architecture ofmicrocapsule composition as well as the systems which enable greaterfreedom to change microcapsule cores for mass production and survivalenhancement of encapsulated cells, recreating 3D microenvironmentthat mimics the natural tissue. The results of our group regarding massproduction of hematopoietic and hepatocyte model stem cells as well asmodular bone tissue formation by using microencapsulation technologywill also be reported. Finally, we will argue that microcapsules can beconsidered as an efficient 3D platform to prepare tissue building blocksas well as mass production of stem cells in dynamic cultures.

کلیدواژه ها:

Cell microencapsulation ، Stem Cells ، Modular tissue formation