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Updated: Aug 12, 2026
An In Vitro Approach to Photodynamic Therapy
Published on: August 17, 2018
Photodynamic therapy in a cell culture model of human intimal hyperplasia
Objective:
To investigate the effectiveness of photodynamic therapy (PDT) in eliminating proliferating vascular smooth muscle cells (VSMCs). This may have a potential role in reducing restenosis rates clinically.
Materials And Methods:
Human VSMCs were successfully cultured from 15 long saphenous veins (SV) and seven restenotic lesions (RL) removed during revision coronary and peripheral vein graft surgery. Cultured VSMCs were incubated with photofrin at doses of 0-5 micrograms/ml for 48 h, and then exposed to 4 J/cm2 of polychromatic light. Cell destruction was quantified by a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.
Results:
Results are expressed as a mean percentage survival +/- standard error. Cells were minimally affected by either photofrin alone (SV: 95.5% +/- 5.3; RL: 119.8 +/- 4.8) or light alone (SV: 75.38% +/- 3.99; RL: 100.1 +/- 11.0). The combination of 2 micrograms/ml of photofrin and 4 J/cm2 of polychromatic light energy, i.e. PDT, was severely toxic to cells derived from saphenous veins (5.52% +/- 0.85) as well as cells derived from restenotic lesions (9.6 +/- 2.3). These doses are comparable to doses that can be achieved in vivo.
Conclusion:
PDT in the appropriate drug and light doses can eliminate human VSMCs, including those responsible for vascular restenosis.
Insights
Photodynamic therapy (PDT) effectively eliminates vascular smooth muscle cells (VSMCs), including those causing restenosis. This research shows PDT
Area of Science:
- Vascular Biology
- Photomedicine
- Cellular Therapeutics
Background:
- Vascular smooth muscle cells (VSMCs) proliferation contributes to vascular restenosis.
- Restenosis remains a clinical challenge after vascular interventions.
Purpose of the Study:
- To evaluate the efficacy of photodynamic therapy (PDT) in eliminating proliferating VSMCs.
- To assess PDT's potential role in reducing clinical restenosis rates.
Main Methods:
- Human VSMCs were cultured from saphenous veins and restenotic lesions.
- Cells were treated with Photofrin and polychromatic light (PDT).
- Cell viability was quantified using a colorimetric assay.
Main Results:
- Photofrin or light alone had minimal effect on VSMC survival.
- PDT (2 µg/ml Photofrin, 4 J/cm² light) significantly reduced VSMC viability from both sources.
- Achieved doses are comparable to in vivo levels.
Conclusions:
- PDT effectively eliminates human VSMCs in vitro.
- PDT demonstrates potential as a therapeutic strategy against vascular restenosis.
