Share Email Print
cover

Proceedings Paper

A rationale for treating leg length discrepancy using photodynamic therapy
Author(s): Stuart K. Bisland; Crystal Johnson; Mohammed Diab; Brian C. Wilson
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

This study investigates the use of photodynamic therapy (PDT) in regulating bone development with a view to its potential role in treating Juvenile leg length discrepancy (LLD). Transgenic mice expressing the luciferase firefly gene upon activation of a promoter sequence specific to the vascular endothelial growth factor (VEGF) gene were subject to benzoporphyrin derivative monoacid (BPD-MA)-mediated PDT in the right, tibial epiphyseal growth plate at the age of 3 weeks. BPD-MA was administered intracardially (2mg/kg) followed 10 mins later by a laser light (690 +/- 5 nm) at a range of doses (5-27J, 50 mW output) delivered either as a single or repeat regimen (x2-3). Contra-lateral legs served as no-light controls. Further controls included animals that received light treatment in the absence of photosensitizer or no treatment. Mice were imaged for VEGF related bioluminescence (photons/sec/steradian) at t= 0, 24, 48, 72 h and 1-4 weeks post PDT. FaxitronTM x-ray images provided accurate assessment of bone morphometry. Upon sacrifice, the tibia and femur of the treated and untreated limbs were harvested, imaged and measured again and prepared for histology. A number of animals were sacrificed at 24 h post PDT to allow immunohistochemical staining for CD31, VEGF and hypoxia-inducible factor (HIF-1 alpha) within the bone. PDT-treated (10 J, x2) mice displayed enhanced bioluminescence at the treatment site (and ear nick) for up to 4 weeks post treatment while control mice were bioluminescent at the ear-nick site only. Repeat regimens provided greater shortening of the limb than the corresponding single treatment. PDT-treated limbs were shorter by 3-4 mm on average as compared to the contra lateral and light only controls (10 J, x2). Immunohistochemistry confirmed the enhanced expression VEGF and CD31 at 4 weeks post-treatment although no increase in HIF-1α was evident at either 24 h or 4 weeks post PDT treatment. Results confirm the utility of PDT to provide localized effects on bone development that may be applicable to other related skeletal deformities.

Paper Details

Date Published: 13 October 2005
PDF: 9 pages
Proc. SPIE 5969, Photonic Applications in Biosensing and Imaging, 596916 (13 October 2005); doi: 10.1117/12.628156
Show Author Affiliations
Stuart K. Bisland, Princess Margaret Hospital/Univ. Health Network (Canada)
Crystal Johnson, Princess Margaret Hospital/Univ. Health Network (Canada)
Mohammed Diab, Univ. of California/San Francisco (United States)
Brian C. Wilson, Princess Margaret Hospital/Univ. Health Network (Canada)


Published in SPIE Proceedings Vol. 5969:
Photonic Applications in Biosensing and Imaging
Brian C. Wilson; Richard I. Hornsey; Warren C. W. Chan; Ulrich J. Krull; Robert A. Weersink; Kui Yu, Editor(s)

© SPIE. Terms of Use
Back to Top