Photodynamic Therapy using Laser and Photosensitizer

DDr. Michael Weber gave us a fantastic talk at the IGMEDT about the possibilities of laser ablation of these tumor stem cells in the blood as well as directly on the cancer itself

Dr. In her inspiring presentation, Ruth Poglitsch showed us the possibilities of intensive high-dose VitC therapy (with artesunate and ALA) and, above all, photodynamic blood laser therapy with photosensitizer

entire congress to watch / listen to including the presentation slides

Here is the complete package of the 3-day congress at a “ridiculous price” recorded in the best video quality by Andrea + Josef Hager, AH-EFFEKT.AT – congress recordings (their program is almost extraterrestrial and the prices are really cheap)
Contact details: Tel.: +43/ (0)664/ 44 99 400 E-Mail: office(@)ah-effekt.at

Photosensitizers are key components of photodynamic therapy (PDT), a treatment method used in oncology and other medical fields. They work by absorbing light of certain wavelengths to initiate photophysical and photochemical processes that have therapeutic effects. Here is a brief overview of how they work:

1. Absorption of light: After administration and accumulation in the target tissue, typically cancer cells or pathogenic microorganisms, photosensitizers absorb light of a specific wavelength. This energy absorption brings the molecules into an excited state.

2. Energy transfer: From the excited state, photosensitizers can transfer energy to neighboring oxygen molecules, converting them into reactive oxygen species (ROS), particularly singlet oxygen, a highly reactive form of oxygen.

3. Cell death and tissue damage: The reactive oxygen species generated can cause cellular damage resulting from the oxidation of cell membranes, proteins and DNA. These oxidizedive damage leads to cell death, either by apoptosis (programmed cell death) or necrosis (immediate cell death).

4. Selective toxicity: The selectivity of PDT is based on the fact that photosensitizers are preferentially concentrated in malignant cells or in pathological tissue and the light is specifically directed to these areas, thus sparing healthy tissue.

Photodynamic therapy is particularly effective in the treatment of superficial cancers, such as skin and bladder cancer, and is also used in antimicrobial therapy and in the treatment of age-related macular degeneration. Its non-invasiveness and ability to target treatment make it an attractive option in clinical practice.

The use of photodynamic therapy (PDT) to treat viral infections is an emerging field of research. Various photosensitizers are being tested to determine their effectiveness against viruses. Here are some examples and studies:

Here is the requested list of photosensitizers with the corresponding laser colors for photodynamic therapy (PDT):

1. Methylene blue:

– Laser color: 660 nm (red light)

– Application: Effective against various viruses, including herpes viruses and HPV. Methylene blue has also been studied to combat MRSA and other viruses.

2. Hypericin:

– Laser color: 590 nm (orange light)

– Application: Effective against the hepatitis C virus and HIV. Hypericin is valued for its powerful antiviral properties.

3. 5-Aminolevulinic acid (5-ALA):

– Laser color: 635 nm (red light)

– Application: Used in oncology and for antiviral purposes, where the induced protoporphyrin IX shows antiviral activity.

4. Indocyanine Green (ICG):

– Laser color: 800 nm (near infrared light)

– Application: Investigated for its potential antiviral properties, particularly effective when combined with near infrared light for deeper penetration for viral inactivation.

5. Riboflavin:

– Laser color: 375-445 nm (blue light), with a peak at around 445 nm

– Application: Riboflavin is used in photodynamic therapy, primarily in ophthalmology for corneal crosslinking. It promotes the cross-linking of collagen fibers in the cornea and is used to treat keratoconus and other corneal diseases.

This list provides an overview of some of the most important photosensitizers in antiviral and oncology PDT, along with the optimal wavelengths for light activation.

Research in this area is dynamic, and new data and insights are constantly being generated. The choice of photosensitizer and specific PDT protocols often depends on the type of virus and the specific clinical situation. For the latest studies and comprehensive data, I recommend searching scientific databases such as PubMed to find specific and current research tailored to the respective viruses and treatment protocols.

this list comes from GPT with the question: “which studies are there or which photosensitizers are predominantly used for cancer”

1. Porfimer sodium (Photofrin):

– Laser color: 630 nm (red light)

– Application: Commonly used for lung cancer and esophageal cancer.

2. Temoporfin (Foscan):

– Laser color: 652 nm (red light)

– Application: Used for the treatment of head and neck cancer.

3. Verteporfin (Visudyne):

– Laser color: 690 nm (red light)

– Application: Originally for age-related macular degeneration, also being tested for solid tumors.

4. Chlorin e6 derivatives:

– Laser color: 660 nm (red light)

– Application: Suitable for various types of cancer due to effective light absorption and high oxygen yield.

5. Talaporfin (laserphyrin):

– Laser color: 664 nm (red light)

– Application: Mainly used for the treatment of lung cancer.

6. Indocyanine Green (ICG):

– Laser color: 800 nm (near infrared light)

– Application: Experimentally studied in cancer therapy, especially for tumors that require deeper light penetration.

7. Curcumin:

– Laser color: 420 nm (blue light)

– Application: Curcumin is valued for its antitumor, antioxidant and anti-inflammatory effects. In PDT it is mainly used to treat skin cancer and other superficial tumors, but can also be applied internally using endoscopic techniques.

For the use of green laser light with a wavelength of 532 nm in photodynamic therapy (PDT), there are specific photosensitizers that can efficiently absorb this wavelength of light. Here are some examples of photosensitizers that can be activated at 532 nm:

1. Photofrin (porfimer sodium): Although Photofrin is primarily used at red light (630 nm), it also has absorption peaks at shorter wavelengths, including around 532 nm, making it potentially useful for green light activation. However, the efficiency is lower compared to red light activation.
2. Methylene blue: Methylene blue has a broad absorption spectrum and can also be excited at 532 nm, although it is more optimally used at wavelengths around 660 nm. At 532 nm, the efficiency is reduced, but it can still show some photodynamic activity.
3. Aluminum phthalocyanine (AlPc): This class of phthalocyanines shows good absorption properties at the green laser wavelength. They are powerful in generating singlet oxygen and are being researched for various therapeutic applications.
4. Chlorophyll derivatives: Some modified chlorophyll derivatives can also be effective at 532 nm. However, these are less common and are often still in the research phase.

It is important to note that most established photosensitizers in PDT are optimized for red light as this penetrates deeper into the tissue. Green light is used less frequently as it penetrates less deeply, limiting its application to more superficial treatment areas. Therefore, when choosing a photosensitizer for use with a green laser, special attention should be paid to the specific clinical application and the properties of the target tissue.

Green laser light (typically at a wavelength of 532 nm) is used in intravenous laser therapy (IVLT) for various medical and therapeutic applications beyond photodynamic therapy. Here are some of the main uses:

1. Vascular diseaseen: Green laser light is used to improve microcirculation. It can help improve blood flow properties and increase oxygen supply in tissue, which can be particularly beneficial in conditions such as peripheral arterial disease or diabetic neuropathy.

2. Wound healing: Due to its stimulating effect on microcirculation and cell regeneration, green light in IVLT can support and accelerate the healing processes of wounds. It promotes collagen formation and can improve wound healing in chronic wounds.

3. Anti-inflammatory effects: Green light can have anti-inflammatory effects that may be useful in the treatment of inflammatory diseases such as rheumatoid arthritis or other systemic inflammatory processes.

4. Immunomodulation: There is evidence that green laser light can affect the immune system and modulate the immune response, which could potentially be used in the treatment of autoimmune diseases and to strengthen the general immune defense.

5. Pain management: Green laser light is also used for pain relief, especially in chronic pain conditions. It can calm nerves and has an analgesic effect that may be helpful in the treatment of neuropathic pain and other chronic pain syndromes.

6. Psychological effects: Some studies suggest that green light may have positive effects on well-being and mood, making it a potential therapeutic option for treating depression and anxiety.

Intravenous green light laser therapy is an innovative form of treatment that is gaining popularity due to its low invasiveness and wide applicability in various medical fields. However, the exact mechanisms and effectiveness are still the subject of current research and clinical trials.

Yellow laser light, often at a wavelength of around 577 nm to 585 nm, is used less frequently in photodynamic therapy (PDT) than red or blue light because it requires specific absorption properties of the photosensitizers. However, there are some photosensitizers that can be effectively activated at these wavelengths. Here are some examples:

1. Verteporfin (Visudyne): Although verteporfin is most commonly activated with light at 690 nm, it also has absorption ranges that cover the yellow light spectrum. Verteporfin can be used with yellow light, but with less efficiency than with red light.

2. Methylene blue: Methylene blue exhibits absorption properties across a broad spectrum, including the yellow light range. It is not the optimal wavelength for methylene blue, but can still show some activity.

3. Hypericin: Hypericin absorbs in the yellow light range, among other areas, but the effectiveness in this wavelength range is less than at the optimal wavelength of about 590 nm.

The use of yellow laser light in PDT is limited because most photosensitizers are optimized for more effective absorption at other wavelengths. The use of yellow light could be useful in special cases where specific tissue depths or certain types of cells are to be targeted, where lower light penetration is sufficient or even preferred. In general, however, further research and development is needed to improve the use and effectiveness of photosensitizers with yellow light.