title: Phase-separated chitosan-fibrin microbeads for cell delivery.
abstract: Matrix-enhanced delivery of cells is a promising approach to improving current cell therapies. Our objective was to create cell-laden composite microbeads that combine the attractive features of the natural polymers chitosan and fibrin. Liquid polydimethylsiloxane was used to emulsify a chitosan-fibrinogen solution containing suspended human fibroblast cells, followed by initiation of thrombin-mediated polymerization of fibrin and thermal/pH-mediated gelation of chitosan. Chitosan/fibrin weight percent (wt%) ratios of 100/0, 75/25, 50/50 and 25/75 were investigated. Microbead diameters ranged from 275 ± 99 µm to 38 ± 10 µm using impeller speeds from 600 to 1400 rpm. Fibroblasts remained viable on day 1 post-fabrication in all matrices, but cell viability was markedly higher in high-fibrin microbeads by day 8 post-fabrication. Cell spreading and interaction with the extracellular matrix was also markedly increased in high-fibrin matrices. Such composite microbeads containing viable entrapped cells have potential for minimally invasive delivery of cells for a variety of tissue repair applications.
authors: Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Zhewei
authors: Z
authors: Chen
authors: Limin
authors: L
authors: Wang
authors: Jan P
authors: JP
authors: Stegemann
mesh_terms: D002470:Cell Survival; D017690:Cell Transplantation / Q000379:methods*; D064987:Cell- and Tissue-Based Therapy / Q000379:methods*; D018914:Cells, Immobilized; D048271:Chitosan / Q000737:chemistry*; D005109:Extracellular Matrix / Q000378:metabolism; D005337:Fibrin / Q000737:chemistry*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000637:transplantation; D006801:Humans; D008863:Microspheres; D010316:Particle Size; D044367:Phase Transition; D058105:Polymerization; D014945:Wound Healing
chemical_list: D005337:Fibrin; D048271:Chitosan