Exposure of 3T3 mouse Fibroblasts and Collagen to High Intensity Blue Light

The field of tissue engineering is continually expanding and advancing with the development of hybrid biomaterials incorporating active biomolecules, such as mammalian cells and DNA, into scaffolds. Sterilization of these biomaterials for clinical use has become an issue as the most common methods of sterilizing biomaterials, gamma radiation and ethylene oxide treatment, not only have a detrimental effect on the base scaffold, but are also incompatible with biological molecules. There has been long standing interest in the effect of light on biological cells and tissues. Recently, exposure to blue light has become of interest for applications including skin treatment (acne vulgaris) and for the inactivation of problematic microorganisms. High-intensity blue light in the 405 nm region has previously been shown to be an effective bacterial decontamination method and may have a potential application for biomaterials. This study investigated the effect of blue light treatment on both the structure of collagen, the most widely used scaffold for tissue engineering applications, and on the viability of a mammalian cell line (3T3 mouse fibroblasts). Type 1 collagen solution was treated with the blue light (405 nm) at 10 mW/cm(2) for 1 hour and SDS-PAGE analysis used to determine the effect on the gross structure of the collagen monomer. To determine the effect of the blue light exposure (1.0 mW/cm(2) for 1 hour) on mammalian cell viability the following methods were used: MTT and Neutral Red microplate assays, measurement of reduced glutathione and protein content, and leakage of cytoplasmic lactate dehydrogenase (LDH) activity. Results show that blue light treatment, for the power densities detailed above, had no noticeable effect on the gross structure of the collagen monomer, nor did it affect the viability, redox state, growth rate or LDH leakage of 3T3 cells.