Related Experiment Video
Updated: Aug 8, 2026
Non-invasive In Vivo Fluorescence Optical Imaging of Inflammatory MMP Activity Using an Activatable Fluorescent Imaging Agent
Published on: May 8, 2017
Influence of light delivery on photodynamic synovectomy in an antigen-induced arthritis model for rheumatoid
K Trauner1, R Gandour-Edwards, M Bamberg
1Department of Orthopaedic Surgery, UC Davis Medical Center, Sacramento, California 95819, USA.
Background And Objective:
Minimally invasive synovectomy techniques have been unsuccessful due to lack of selectivity. The purpose of this study was to evaluate the potential of photodynamic therapy to destroy diseased synovium in an antigen-induced arthritis model.
Study Design/Materials And Methods:
Three sets of experiments evaluated the biodistribution and treatment effects of Photofrin (PF) in rabbits with bilateral knee antigen-induced arthritis. The first set of experiments evaluated the biodistribution of PF in articular tissues of 30 rabbits from 6-72 hours after systemic injection of 2 mg/kg. In the second series of experiments, light was delivered to the knee joint via cleaved optical fibers, whereas for the third, light was delivered via a 600 microm diffusion tip fiber. Tissues were harvested at 2 and 4 weeks posttreatment.
Results:
The biodistribution experiments demonstrated maximal uptake in inflamed synovium at 48 hours and a lack of uptake in normal tissues. With bare cleaved fibers, necrosis was observed in one specimen at 2 weeks and was absent in all specimens at 4 weeks. In the third experiment, synovial necrosis was observed in 3 of 7 specimens at 2 weeks and 3 of 8 at 4 weeks. No damage to articular cartilage or periarticular tissues was seen with either mode of light delivery.
Conclusion:
These studies indicate that selective destruction of synovium can be achieved with PF and suggest that optimization of light delivery techniques will play an important role in development of this new technique.
Insights
Photodynamic therapy using Photofrin (PF) shows potential for selectively destroying diseased synovium in arthritis models. Further research into light delivery methods is needed to optimize this promising treatment for joint diseases.
Area of Science:
- Orthopedics
- Biomedical Engineering
- Photochemistry
Background:
- Minimally invasive synovectomy lacks selectivity for treating joint diseases.
- Antigen-induced arthritis in rabbits serves as a model for studying synovium destruction.
Purpose of the Study:
- To evaluate photodynamic therapy (PDT) with Photofrin (PF) for selective synovium destruction.
- To assess PDT efficacy in an antigen-induced arthritis rabbit model.
Main Methods:
- Systemic injection of Photofrin (PF) in rabbits with induced arthritis.
- Evaluation of PF biodistribution in articular tissues (6-72 hours post-injection).
- Comparison of two light delivery methods (cleaved optical fibers vs. diffusion tip fiber) for PDT.
Main Results:
- Photofrin (PF) showed maximal uptake in inflamed synovium at 48 hours, with minimal uptake in normal tissues.
- Synovial necrosis was observed with both light delivery methods, with no damage to cartilage or surrounding tissues.
- The diffusion tip fiber showed slightly better results in inducing necrosis compared to bare cleaved fibers.
Conclusions:
- Photodynamic therapy with Photofrin (PF) can selectively destroy diseased synovium.
- Optimization of light delivery techniques is crucial for the clinical development of PDT for arthritis.
