Injectable hyaluronic acid scaffolds for cartilage tissue engineering

Every year tens of millions worldwide suffer from cartilage damage, caused by mechanical degradation, trauma or disease. Because of the lack of blood supply and low cell concentration within the tissue, cartilage has very limited regenerative ability. Although current treatments can provide symptomatic relief, the results vary greatly among individuals, and newly formed tissue often does not duplicate the structure, composition or mechanical properties of normal cartilage. Therefore, in recent years, tissue engineering has emerged as an alternative therapy. Tissue engineering enhances the body's natural healing capacity by providing cells, signaling molecules, and an environment in the form of a scaffold that is conducive to tissue growth. This project has focused on the development of a tissue engineering scaffold for cartilage regeneration. Disadvantages to current scaffolds include the fact that they require surgery for implantation, and that they are difficult to mold to the exact shape of the defect site. Hence, the motivation of this thesis is to develop an injectable scaffold that can be administered in a minimally invasive manner, and that allows for scaffold formation in situ, naturally shaping the construct into the shape of the defect, and thus promoting integration and stability To this end, we have developed a thermoresponsive injectable scaffold for cartilage tissue engineering. The scaffold was injected as a liquid at room temperature, and gelled at the target site in response to the change to body temperature, resulting in a biocompatible, bioresorbable substrate for tissue growth. Our approach involved suspending thermoresponsive liposomes, which encapsulated a crosslinking agent, in a polymer solution. At room temperature, the crosslinking agent was separated from the polymer by the lipid membrane, hence the precursor solution remained a liquid and injectable. Upon injection and exposure to body temperature, the lipids experienced a phase transition, which significantly increased the membrane permeability and led to the release of the crosslinking agent and reaction with the polymer, forming a networked scaffold.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Ren, Cindy D

Advisor dc:contributor.advisor

• Jackie Y. Ying.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/46025

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/46025