Tissue scaffold monitoring with UV probe

The degradation of a chitosan scaffold used in tissue engineering can be monitored in situ and in real time using a fluorescent probe which is attached to chitosan before surgery. Alicia El Haj and colleagues from Keele University and the University of Leeds found a way to attach tetramethylrhodamine isothiocyanate (TRITC) onto the backbone of chitosan which was used as a scaffold for the growth of new tissue.

Techniques already exist to measure the degree of scaffold loss after surgery but they are destructive and not easy to apply to real-time studies. The new process, described in the Journal of Tissue Engineering and Regenerative Medicine, attached TRITC to the backbone of deacetylated chitosan membranes which were used for in vitro and in vivo tissue growth.

In an initial degradation experiment, the weight loss of the membrane was correlated with decreases in the fluorescence intensity, measured by confocal microscopy, as the polymer breaks down. In subsequent studies, the human osteoblast-like cell line MG63 was grown for 14 days on the labelled membranes. During this period, the cells produced collagen and the fluorescence intensity of the labels fell over time. The labelled membranes were also checked in vivo by inserting them under the skin of mice. The fluorescence was measured over 14 days and showed a sharp decrease over the first four days, followed by a more gentle loss.

TRITC proved to be biocompatible and supported cell growth. However, before the modified chitosan scaffolds can be adapted for clinical applications, the effects of "metabolic and biological activities in individual animals and the effect of scaffold geometry on the degradation profile require further investigation."