Production of Cell Enclosing Silk Derivative Microsphere in Uniform Size Distribution Through Coaxial Microfluidic Device and Horseradish Crosslinking Reaction
Abstract BackgroundSilk fibroin (SF) as a natural polymer holds great potential in biomedical research because of its biocompatibility, easy processing, high toughness, and strength. However, slow gelation time has narrowed its applications, specifically in cell-laden microparticles that are versatile structures for tissue engineering due to their unique features. In addition, most crosslinking methods used to decrease gelation time did not occur in a mid-condition. Methods This study aimed to use modified SF with phenol conjugation to accelerate crosslinking mediated via horseradish peroxidase (HRP)/ hydrogen peroxide (H2O2) in a co-flow high-throughput microfluidic device for the ultimate goal of cell-laden silk fibroin-phenol (SF-Ph) microparticles formation. The physical and biochemical properties of fabricated cell-laden SF-Ph were evaluated to reveal its potential for tissue engineering.ResultsThe monodisperse microparticles in shape and size were formed in various diameters changing from 300 to 80 µm by altering oil phase velocity from SF-Ph substrate. More than 90% cell viability and three times cells upregulation of mitochondrial activity of enclosed-cells in microparticles with 150 ± 32 µm diameters revealed that these structures were suitable subcultures produced through a mild process based on morphological and MTT assays. It was noticed that cells approximately cover the microparticles until the 15th day. ConclusionSpherical micro-tissue formation in microparticles, resulting from cell growth promoted by cell-cell and cell-matrix interactions, adds significant weight to this method's applications.