Water-sensitive Gelatin Phantoms for Skin Water Content Imaging

Oxygen supply to tissues can be seriously impacted during wound healing. Edema (accumulation of fluids in interstitial space) can increase the distance between capillaries, thus decreasing oxygen supply to cells. There is no standard clinical tool for quantification of edema, and early edema detection (preferably preclinical) is of great clinical need. Multispectral imaging can be a helpful clinical tool to characterize water content in the skin. However, to develop and validate this technology, a reliable water-sensitive preclinical model has to be developed. The scope of this work is to develop a water-responsive skin model and assess the feasibility of extracting water content using multispectral imaging. Methods: A phantom fabrication protocol has been developed. The phantoms are based on the gelatin crosslinked with glutaraldehyde. TiO2 nanoparticles were added to mimic the optical properties of the skin. To emulate various water content, phantoms were dipped in the water for various duration. The phantoms were imaged using the Multi-Spectral Imaging Device (MSID) (Swift Medical Inc, Toronto). MSID is a multispectral imaging system for visualization of tissue chromophores in surface tissues. It uses 12-bit scientific-grade NIR-enhanced monochrome camera (Basler, Germany) and ten wavelength light source (600-1000nm range) to visualize the distribution of oxy-, deoxyhemoglobins, methemoglobin, water, and melanin. The imaging distance is 30cm, the field of view: 7x7cm. Results: Initial results show that the developed model mimics the optical scattering properties of the skin. MSID was able to extract water content using a full set (ten wavelengths) and a subset (three wavelengths) of channels. Conclusions: A new water responsive model for skin moisture imaging has been developed. Initial experiments with multispectral imaging of these phantoms show feasibility of tissue water content imaging with Si-based cameras.