title: Micrometer scale guidance of mesenchymal stem cells to form structurally oriented cartilage extracellular matrix.
abstract: Tissue engineering is a possible method for long-term repair of cartilage lesions, but current tissue-engineered cartilage constructs have inferior mechanical properties compared to native cartilage. This problem may be due to the lack of an oriented structure in the constructs at the microscale that is present in the native tissue. In this study, we utilize contact guidance to develop constructs with microscale architecture for improved chondrogenesis and function. Stable channels of varying microscale dimensions were formed in collagen-based and polydimethylsiloxane membranes via a combination of microfabrication and soft-lithography. Human mesenchymal stem cells (MSCs) were selectively seeded in these channels. The chondrogenic potential of MSCs seeded in these channels was investigated by culturing them for 3 weeks under differentiating conditions, and then evaluating the subsequent synthesized tissue for mechanical function and by type II collagen immunohistochemistry. We demonstrate selective seeding of viable MSCs within the channels. MSC aligned and produced mature collagen fibrils along the length of the channel in smaller linear channels of widths 25-100 μm compared to larger linear channels of widths 500-1000 μm. Further, substrates with microchannels that led to cell alignment also led to superior mechanical properties compared to constructs with randomly seeded cells or selectively seeded cells in larger channels. The ultimate stress and modulus of elasticity of constructs with cells seeded in smaller channels increased by as much as fourfolds. We conclude that microscale guidance is useful to produce oriented cartilage structures with improved mechanical properties. These findings can be used to fabricate large clinically useful MSC-cartilage constructs with superior mechanical properties.
authors.affiliation: Department of Chemical Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7217, USA.
authors.forename: Chih-Ling
authors.initials: CL
authors.lastname: Chou
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Rivera
authors.forename: Takao
authors.initials: T
authors.lastname: Sakai
authors.forename: Arnold I
authors.initials: AI
authors.lastname: Caplan
authors.forename: Victor M
authors.initials: VM
authors.lastname: Goldberg
authors.forename: Jean F
authors.initials: JF
authors.lastname: Welter
authors.forename: Harihara
authors.initials: H
authors.lastname: Baskaran
mesh_terms: D002356:Cartilage / Q000166:cytology*; D002448:Cell Adhesion / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods
chemical_list: D006025:Glycosaminoglycans; D003094:Collagen