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Applications of Photosensitisers to Cancer, Viral, Bacterial Disease and Immunology Terry Wright

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Presentation on theme: "Applications of Photosensitisers to Cancer, Viral, Bacterial Disease and Immunology Terry Wright"— Presentation transcript:

1 Applications of Photosensitisers to Cancer, Viral, Bacterial Disease and Immunology
Terry Wright

2 Non-toxic Sensitizer Cell Survives Photosensitising agent Dye molecule
Not cytotoxic Taken up by cell (i.e. staining) Cell Cell Survives

3 Tuned Laser Light Cell Survives Light exposure Red or near IR
Light (Red) Light exposure Red or near IR Cell is transparent Not cytotoxic No heating Cell Cell Survives

4 Cell Dies!! ROS Flood = Death PS + Light Cell not transparent
Light (Red) PS + Light Cell not transparent Energy is absorbed Reactive oxygen species Oxidative stress Cell Cell Dies!!

5 Chemical Targeting

6 Nanomolecular Delivery
Proprietary sensitiser formulation 20 nm nanoparticles containing sensitiser Cationic surface charge targets cancer Reduced sensitisation of healthy tissue Eyes Skin Rapid clearance 1wk vs 6

7 Nanomolecular Delivery
Accumulation of sensitizer in skin of Bufo Marinus with nanomolecule Same sensitizer and same dose without nanomolecule formula

8 Gentle Death High dose: necrosis Minimum dose: apoptosis
Sensitiser bound to mitochondrial membrane Cleave Bcl-2 / Bcl-XL Loss of mitochondrial membrane potential Programmed cell death follows

9 S. S. Stylli and A. H. Kaye, J. Clin. Neurosci. 13, 709-717 (2006)
PDT of Cancer Barret’s Oesophagus Adjunct therapy for solid tumours Systemic administration Non-surgical debulking Killing microscopic remnants Topical application for non-melanoma SC Glioblastoma Multiforme at RMH 50% survival at 10 yr, vs ~5% at 2 yr chemo S. S. Stylli and A. H. Kaye, J. Clin. Neurosci. 13, (2006)

10 PDT Causes in-situ Vaccination
Adaptive immunity frequently observed Remote metastases controlled / eliminated Tc / NK cells, macrophages Animal models resistant to rechallenge Adoptively transferable Inflammation due to necrosis, immune response due to apoptosis? F.H. van Duijnhoven et al., Immunobiol. 207, (2003).

11 Activating the Immune System
Because PDT creates a perfect vaccination against the cancer in the patients body, the immune system immediately begins to attack the cancer. With antibody therapy the suppressor t-cells are activated. When killing a large tumor up to 95% of the bodies white cells rush to attack the cancer

12 Disabling the Defense Cancer mounts a defense against the immune system. T-cells are converted to suppressor cells which suppress new TIL. Immature myeloid cells are converted to suppressors via ROS. Antibodies disable the defense systems mounted by cancer to enable immune attack

13 Risk Factors with PDT High level necrotic kills can cause swelling and inflammation- severe risk for brain tumors. Even with apoptotic kills the amount of cancer killed can be huge. Toxin load can be challenging for hepatic and renal elimination, so maintainance of organ health is vital.

14 Absorption/Fluorescence Spectra
λ = 685 nm (excitation) Fluorescence detection Absorption Emission

15 Detection of Fluorescence
Laser excitation Near-IR fluorescence Camera with IR filter Laser: 685nm IR: nm

16 Image on PC Screen

17 Lymphatic Involvement
When cancer is not present in lymph nodes, no fluorescence is seen, as in the left picture above. When cancer is present, photodynamic fluorescence is very obvious. A few minutes of laser will resolve this condition.

18 Metastatic Bone Cancer
Patient 2: metastasis in the manubrium Before Treatment After Treatment

19 Metastatic Bone Cancer
Skull mets Ankle mets

20 Post-Salvage Breast Cancer
Following surgery, chemotherapy and radiotherapy

21 Post-Salvage Breast Cancer
Following Photodynamic Therapy

22 Post-Salvage Breast Cancer

23 Psoriasis Active leukocytes accumulate sensitiser
Topical PDT of skin autoimmune disorders Psoriasis treated with our sensitiser Two weeks later

24 Scleroderma treated with our sensitiser
Scleroderma Treated over two years ago No indication of return to date Scleroderma treated with our sensitiser

25 Multiple Sclerosis Before treatment After treatment
Multiple Sclerosis treatment is remarkably easy. A one hour infusion with laser illumination at the same time resets the immune system resulting in long lasting remission of symptoms

26 Diabetes Diabetes Mellitus type I has been treated in animal models.
Mice genetically programmed to develop DM I treated with PDT have a 60% lower chance of developing DM I. Both types of Diabetes are now being considered as autoimmune diseases. In one diabetic patient treated for cancer, blood sugar levels dropped from 10+ to six range within days after treatment.

27 Diabetic Wound Healing
Wounds which normally don’t heal for days or weeks can be treated with a topical application of sensitizer and a few minutes of laser. Wound healing proceeds normally after treatment

28 Bacteria Golden Staph has been tested to 20 generations of LD 50 kills
It has never shown indication of developing resistance to PDT. PDT for golden staph can be delivered fast and cost effectively. In Staph from recent injuries or surgeries, the sensitizer can be administered topically and will absorb through the wound. Bloodborne golden staph can be treated with IV infusions.

29 Conclusion PDT: a clinical reality in most developed countries
But Australia is trailing ~15 years behind No sensitiser approved for systemic use Locally developed and manufactured: Portable laser, >5W at present and >10W planned Photosensitisers: systemic, intratumoural, topical IR camera and uniform illumination

30 Questions?

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