A MULTISCALE APPROACH TO STEM CELL-BASED CHONDROGENESIS FOR CARTILAGE REPAIR

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 (hMSCs) were selectively seeded in these channels. The chondrogenic potential of hMSCs seeded in these channels was investigated. We demonstrate selective seeding of viable hMSCs within the channels. hMSC 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 four folds. Furthermore, we extended the 2-dimensional finding and successfully created 3-dimensional large scale constructs (3.5 mm in diameter × 18 mm in length) with microscale architecture for in vivo applications. Histology and immunohistochemistry indicated extensive GAG and collagen type II production in 3-dimensional construct, which are both indicative of chondrogenesis. Our results show that the microscale guidance channels incorporated within the 3-dimensional cartilage constructs lead to the production of aligned cell-produced collagenous matrix and enhanced mechanical function. The tissue modulus of elasticity of 3-dimensional cartilage constructs containing guidance increased by as much as six times compared to constructs without channels. Overall, these findings offer new insight into how microscale guidance channel regulates matrix deposition and long term construct development.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Chemical Engineering

Grantor dc:publisher

Case Western Reserve University School of Graduate Studies

Year dc:date

2013

Author dc:creator

• Chou, Chih-Ling

Contributors dc:contributor

• Baskaran , Harihara

• Biomedical Research

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=case1365172430

OAI identifier oai:identifier

oai:etd.ohiolink.edu:case1365172430