An analysis of the integration between articular cartilage and nondegradable hydrogel using magnetic resonance imaging.
A hydrogel is a highly hydrated polymer gel suitable for use as a scaffold for tissue engineering. One important application is to the repair of cartilage defects due to injury or osteoarthritis. Integration of the hydrogel with surrounding tissue is critical for the long-term functionality of the implant; however direct visualization of integration is difficult and invasive. Accordingly, we used MRI to noninvasively investigate the integration of hydrogel in cartilage. Two integration methods were assessed: (1) cartilage-initiated and (2) chemical, using chondroitin sulphate-methacrylate-aldehyde (CS-MA-ald) as an adhesive. These were compared to a control group, that is, standard, nonintegrated hydrogel photopolymerization. Spatial variation of the transverse relaxation time, T(2), across the transition region was used to determine the effectiveness of integration. In the CS-MA-ald group only, two interfaces were found. This provides evidence of an intermediate adhesive layer between hydrogel and cartilage. Second, the thickness of the transition region between hydrogel to cartilage in the CS-MA-ald group was 1.32 mm as compared to 1.20 mm and 1.17 mm in the tissue-initiated and nonintegrated groups, respectively. We interpret this as a more gradual transition region of hydrogel to cartilage and hence a greater degree of integration when an adhesive layer is present.
Ramaswamy
Sharan
S
National Institute on Aging, National Institutes of Health, Laboratory of Clinical Investigation, Gerontology Research Center, Room 4D-08, 5600 Nathan Shock Drive, Baltimore, Maryland 21224, USA.
Wang
Dong-An
DA
Fishbein
Kenneth W
KW
Elisseeff
Jennifer H
JH
Spencer
Richard G
RG
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D001843:Bone Cements / Q000737:chemistry / Q000378:metabolism; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D020100:Hydrogels / Q000737:chemistry / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008422:Materials Testing / Q000379:methods; D012038:Regeneration / Q000502:physiology*; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods
D001672:Biocompatible Materials; D001843:Bone Cements; D020100:Hydrogels