Optical characterization of collagen scaffolds using multispectral images and a light-scaffold interaction model

The study of biomaterials and their interaction with biological tissue is one of the fastest growing areas in the generation of therapeutic alternatives in clinical practice. Biomaterials can be used in order to promote the healing of skin lesion, such as cutaneous ulcers caused by: venous insufficiency, pressure, diabetes, and tropical diseases. The use of biomaterials for tissue engineering leads to the challenge of creating non-invasive tools for tissue reparation follow-up. Those tools can be developed based on instruments and methods that allow measuring physical, chemical, and optical properties of materials. Among the biomaterials used for tissue regeneration, collagen is one of the most used for the creation of scaffolds. Collagen scaffolds offer the good conditions for cellular adhesion and growth on to their surface. This paper proposes the use of a light-material interaction model, for the processing of multispectral images of collagen scaffolds. The model together with an optimization approach, allows the optical characterization of collagen scaffolds by means of absorption and scattering coefficients in the visible-near infrared spectrum. Multispectral images of collagen scaffolds built from six different type of gelatin concentrations were processed with the proposed model and the Nelder-Mead simplex optimization approach. As a result, we obtain that the absorption coefficients considered in the mathematical model are highly related to the used gelatin concentrations of the evaluated scaffolds.