Abstract
Proton nuclear magnetic resonance (NMR) relaxometry can give informations about hydrogel scaffold properties. As these properties can be modified with culture time and conditions according to scaffold biodegradability and new tissue biosynthesis, the aim of this research was to test the efficiency of this noninvasive NMR technique in the followโup of 3D cultures for tissue engineering. The distributions of proton relaxation times T~1~ and T~2~ have been measured on cylindrical gel samples of different types of alginate, in the presence or absence of hyaluronate, in gels or bioconstructs with encapsulated chondrocytes cultured for 30 days in normal or reduced weight conditions. It was found that T~2~ increases with the mannuronate/guluronate ratio in alginate samples and with the presence of hyaluronate. The distributions of both T~1~ and T~2~ result wider for bioconstructs cultured in normal gravity than for those cultured in reduced weight conditions. Neither cell growing nor collagen production but only GAG neosynthesis have been demonstrated in our experimental conditions. In conclusion, T~2~ is sensitive to the gel properties (possibly to the rigidity of macromolecular components). The homogeneity of bioconstructs can be monitored by the distribution of T~1~ and T~2~. We propose that nonspatially resolved NMR relaxometry can efficiently be used in monitoring tissue development in a biodegradable scaffold for tissue engineering. ยฉ 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007