Molecular Imaging-Assisted Optimization of Hsp70 Expression during Laser-Induced Thermal Preconditioning for Wound Repair Enhancement

• Published in: Journal of investigative dermatology Vol. 129; no. 1; pp. 205 - 216
• Main Authors: Wilmink, Gerald J., Opalenik, Susan R., Beckham, Joshua T., Abraham, Alexander A., Nanney, Lillian B., Mahadevan-Jansen, Anita, Davidson, Jeffrey M., Duco Jansen, E.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.01.2009; Nature Publishing Group; Elsevier Limited
• Subjects: Animals; Biological and medical sciences; Biomechanical Phenomena; Collagen - metabolism; Dermatology; Hot Temperature; HSP70 Heat-Shock Proteins - metabolism; Immunohistochemistry; Laser-Doppler Flowmetry - methods; Lasers; Macrophages - metabolism; Medical sciences; Mice; Mice, Transgenic; Rats; Risk; Skin - radiation effects; Wound Healing; Repair; Dermatology; Wound; Optimization
• ISSN: 0022-202X; 1523-1747
• DOI: 10.1038/jid.2008.175

Patients at risk for impaired healing may benefit from prophylactic measures aimed at improving wound repair. Several photonic devices claim to enhance repair by thermal and photochemical mechanisms. We hypothesized that laser-induced thermal preconditioning would enhance surgical wound healing that was correlated with hsp70 expression. Using a pulsed diode laser (λ=1.85μm, τp=2ms, 50Hz, H=7.64mJcm−2), the skin of transgenic mice that contain an hsp70 promoter-driven luciferase was preconditioned 12hours before surgical incisions were made. Laser protocols were optimized in vitro and in vivo using temperature, blood flow, and hsp70-mediated bioluminescence measurements as benchmarks. Biomechanical properties and histological parameters of wound healing were evaluated for up to 14 days. Bioluminescent imaging studies indicated that an optimized laser protocol increased hsp70 expression by 10-fold. Under these conditions, laser-preconditioned incisions were two times stronger than control wounds. Our data suggest that this molecular imaging approach provides a quantitative method for optimization of tissue preconditioning and that mild laser-induced heat shock may be a useful therapeutic intervention prior to surgery.