Autofluorescence assessment of extracellular matrices of a cartilage-like tissue construct using a fluorescent image analyser.

For the assessment of tissue-engineered cartilage, easy and precise evaluation methods are anticipated. We have investigated the use of a fluorescent image analyser and the application of fluorescence intensity measurements to describe and evaluate a tissue-engineered cartilage-like tissue construct. We evaluated the matrix production of a tissue-engineered cartilage-like tissue (TCL) construct in vitro using the image analyser. The autofluorescence intensity of the TCL construct was determined using the image analyser driven by a software program after 1, 2, 3 and 4 weeks of culture. The autofluorescence intensity of the TCL construct gradually increased with increasing culture time. However, there was very little change in the autofluorescence intensity of gels without articular chondrocytes as controls. The relationship between the autofluorescence intensity of the TCL construct and the hydroxyproline content, reflecting the collagen content, was investigated. There was a significant correlation between the two items. Our findings demonstrate the ability of a commercial fluorescent image analyser to evaluate the matrix production of the TCL construct in vitro on the basis of objective data, such as the autofluorescence intensity. Therefore, the image analyser can be used to judge the success or failure of the in vitro culture process of TCL construct without a biopsy.