Photodynamic Therapy Treatment to Enhance Fracture Healing

• Main Authors: Akens, Margarete K, Whyne, Cari M, Wilson, Brian C, Yee, Albert J, Nam, Diane
• Format: Report
• Language: English
• Subjects: ANIMAL MODELS; BONE FRACTURES; CANCER; FRACTURE HEALING; HEALING; IMPACT; INFECTION; LONG BONE FRACTURES; Medicine and Medical Research; PHOTODYNAMIC THERAPY; SKIN DISEASES; SPINAL COLUMN; SPINAL METASTASES; THERAPY; TIBIA

Long bone fractures resulting from high impact trauma can result in delayed healing. Photodynamic therapy (PDT) is a non-surgical, non-ionizing minimally invasive local treatment currently used to treat cancer and skin diseases. Surprisingly, recent findings from studying the effect of PDT on spinal metastases have shown that PDT improved the strength and stiffness of the vertebrae. Although variability in fracture generation led to inconclusive findings with respect to bone generation in the closed tibia fracture model (n=17), higher local levels of VEGF were found in PDT treated animals. A critical size defect fracture of the femur was generated in 20 adult female Sprague-Dawley rats. PDT treatment was applied either 1d (n=6) or 7d (n=6) after fracture generation. Qualitatively, a larger callus was seen in the 7d-PDT group, suggesting an important effect of timing on PDT administration. Both PDT treated groups showed evidence of healing and closing of the fracture gap in this critical defect model. Preliminary, quantitative CT measurements support the qualitative findings. Additional CT based imaging and stereological analysis are underway. Histologic processing and analysis of the serum will also be conducted on these animals. The original document contains color images.