Non-invasive continuous imaging approaches to evaluate tissue structure and development

Abstract

As the field of tissue engineering advances toward fully functional organoids and artificially generated tissues, methods to evaluate the condition of the cultured tissue from the beginning to the end continuously grow more importance. The structure and developmental status of tissues in vivo reveal considerably more information than current approaches to discrete analysis like histology. Optical imaging modalities present a promising future regarding its ability to unveil morphological and biochemical changes of the tissue in a continuous manner without compromising its viability. Therefore, in this paper, several popular and emerging methods include Fluorescence Lifetime Imaging, Hyperspectral Imaging, Optical Coherence Microscopy, Light Sheet Fluorescence Microscopy, Near-infrared II Fluorescence Imaging, Mueller-matrix imaging are discussed with regards to their advantages and limitations in tissue engineering research. Although these approaches allow long term monitoring of developing tissue in vivo, they are not suitable in all conditions and lack spatial resolution and depth penetration. The potential of optical imaging on tissue structure and interactions can be further realized by improving upon fixed sample imaging techniques and utilizing multimodal systems.