Posts tagged: photodynamic therapy

Harming our Good Bacteria may be Harming Us in the Long Run

By the time we are 18, we have received 10-20 courses of antibiotics. This antibiotic usage has enabled us to live longer and healthier lives, by overcoming bouts of infections. But there are, of course, drawbacks to this antibiotic consumption. The most obvious and most worrying of these drawbacks, is the development of drug resistant bacteria (superbugs) such as MRSA. However, antibiotics also kill the normal microflora, the ‘good bacteria’ that we need to maintain good overall health. The long term implications of repetitive disruption of our microflora by antibiotics, unfortunately, are not understood and not being adequately investigated.

When in the right concentrations and when the body’s natural immune system is healthy, bacteria are an important part of us. In fact, there are 10 times more bacteria cells in us than there are human cells.5 Human cells and bacteria have developed a symbiotic relationship over time. In order to answer the question of whether harming the good bacteria is harmful to us in the long run, we need to understand more about bacteria.  So how are bacteria beneficial to us?

Firstly, in our stomach, intestines and colon, we have “good” bacteria that play a major role in breaking down our food into nutrients to be absorbed by our body and into waste material that is eventually eliminated.  Along the way, these good bacteria take up colonization sites thereby preventing harmful bacteria, and other pathogens, from taking residence where they do not belong.

Secondly, bacteria can also play a major role in the production of key elements in our body. For example, Bacteroides species of bacteria live in our colon and help us produce Vitamin K, needed for blood clotting. Helicobacter pylori (H. pylori) is another example of the body needing a bacteria to function properly. H. Pylori, while responsible for stomach ulcers in some people when in overabundance, seem to play a major role in the generation of key hormones that control our appetites. H. Pylori appears to affect the regulation of the two hormones, ghrelin and leptin, involved in human energy homeostasis and implicated in the control of food intake such as controlling hunger. Leptin signals to your body it is full while ghrelin stimulates appetite. In one study, it was determined that fewer than 6% of children’s stomachs in the United States, Sweden, and Germany now carry H. Pylori. The lack of Helicobacter pylori has been thought to be linked to the increase in gastroesophageal reflux, Barrett’s esophagus, and esophageal cancer. Interestingly, those lacking H. pylori are also more likely to develop asthma, hay fever or skin allergies.1 Dr. Martin Blaser, a professor of microbiology at New York University Langone Medical Center, suggests ‘that antibiotics may permanently alter your gut bacteria and interfere with important hunger hormones secreted by your stomach, leading to increased appetite and body mass index (BMI)’.3

Our bodies have been living in balance with our bacteria for thousands of years. It is a symbiotic relationship that is now being permanently altered by the use, overuse and misuse of antibiotics. No one knows at this point how seriously antibiotics are harming our long term health prospects. It will take decades worth of research and the resolve of governmental forces to undertake this large scale investigation. However, for today, it is worth asking the question; “By harming our good bacteria, are we not also harming ourselves in the long run?”

References: 1




First Scientific Meeting of the Pan American Photodynamic Therapy Association – April 6th, 2013

This week, the 1st Scientific Meeting of the PanAmerican Photodynamic Therapy Association (PAPDT) will be held in Boston, Massachusetts on Saturday, April 6, 2013, from 8:30am-5:30pm. For the first time the Annual Scientific Meeting will be held in association with the American Society for Laser Medicine and Surgery (ASLMS) to enhance the basic science and clinical interdisciplinary aspects of photodynamic therapy, bringing together scientists, clinicians and engineers with an interest in both photonics and medicine to share their experiences from bench to bedside.

The main theme of this Scientific Meeting will be to discuss the basic science and clinical advances in cancer, antimicrobial and other photodynamic therapeutic applications with the declared focus of improving the scientist/clinician interface.  The PanAmerican Photodynamic  Therapy Association is soliciting abstracts for oral presentations and posters.  Please submit your abstract using the ASLMS online system for submission.  You will need to select “Photodynamic Therapy” as the presentation category.  Important to note, you must either email Michelle directly at so that she knows the abstract is for the PanAmerican Photodynamic Therapy Association.  Students and young researchers are especially welcome.

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PDT Cancer Case Study #1: Invasive Squamous Cell Carcinoma Cured In 6 Weeks

This is a case study by Dr. Merrill Biel of a 69 year old male presenting with a history of right mouth soreness for the past six months. This patient has no history of sore throat, dysphagia, hemoptysis or shortness of breath. He is a smoker (2 ppd for the past 50 years) and drinks two alcoholic beverages per day.

During his mouth examination, irregular cobblestoned mucosa of the entire right floor of the mouth was found (Figure 1). There were three areas each 1 cm in diameter of invasive firm nodules. Biopsies were then obtained and it was determined that the patient had invasive squamous cell carcinoma.  He was staged as a T3N0 superficial squamous cell cancer of the right floor of mouth and ventral tongue.

Left (Figure 1): Patient presents with squamous cell cancer of entire right floor of mouth and ventral tongue. Right (Figure 2): Six weeks post- PDT Treatment, area of tumor healed with normal mobile mucosa and without scar tissue

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Ondine’s Photodisinfection Technology Being Developed To Treat Chronic Sinusitis

Photodisinfection is a highly effective antimicrobial therapy involving non-thermal light and a topically placed photosensitizer. It is currently being used for the treatment of oral infections and nasal decolonization of MRSA and S. aureus. Photodisinfection is also being currently used for the treatment of endotracheal tube biofilms to prevent ventilator associated pneumonia. One of the areas of medical need identified for photodisinfection is for the treatment of chronic sinusitis that has failed surgical and medical therapies. It is estimated that there are more than 500,000 of these people suffering in the US alone, and this number grows by 10% annually.

Polymicrobial biofilms, many of them antibiotic resistant, have been significantly implicated in the etiology of this chronic indolent disease process and its associated inflammatory processes.  Preclinical studies we have conducted demonstrate the effectiveness of photodisinfection to selectively photoeradicate a broad spectrum of biofilm micoorganisms, including antibiotic resistant S. aureus, P. aerugenosa and fungal species, without causing injury to tissue or mucosa.

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Ondine’s Latest Hire: Leonie Markhorst, Communications Extraordinaire

It is with great pleasure that we add Leonie Markhorst to the Ondine family. As our new Marketing Coordinator, Leonie is responsible for managing the projects and internal communications that will help bring Ondine’s technology to even more patients and healthcare providers.

A Dutch native, Leonie graduated from Utrecht University with a Bachelors degree in Communications. At age 19, she founded a successful online jewellery business before beginning her career as an Internal Communications Specialist for a large global organization. There, she was responsible for the operational tasks within her department, managed corporate events for up to 1,500 attendees, and acted as an advisor to line management. In 2011, she moved from the Netherlands to Vancouver to pursue bigger opportunities.

In her spare time, Leonie enjoys fashion, interior design and dance. She is fluent in three languages and is a contributing editor for a renowned online fashion magazine. The Ondine team is extremely pleased to have Leonie join us, and we cannot wait to get her started on some very exciting projects!

Ondine Biomedical Inc Proudly Supports The PanAmerican PDT Association

Ondine Biomedical Inc. is a proud supporter of the mission and goals of the PanAmerican Photodynamic Therapy Association. Launched last month, the Association’s purpose is to galvanize the basic science and expertise of photodynamic therapy in the Americas. This will help encourage the study and practice of PDT in the treatment of animal and human diseases.

Many of you may not know that photodynamic therapy has been around for centuries. In fact, the earliest recorded treatment using a photosensitizing agent and a light source occurred in ancient Egypt over 3,000 years ago. Vegetable and plant substances were used as photosensitizers and sunlight was used as the light source. Patients suffering from skin diseases such as vitiligo had the photosensitizers topically applied to the damaged area, and the resulting photochemical reaction restored their tissue to a healthier state. In some cases, it even helped repigment their skin to its normal color.

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Photodynamic Therapy Saves Boy Given Six Months To Live

Connah Broom is a very luck young man. Diagnosed at the age of four with stage 4 neuroblastoma, Connah was given six months to live. Eleven tumours had developed on his neck, stomach, legs, and areas near his heart. Seven months of chemotherapy failed to improve his condition and surgery was no longer an option as the tumours were located too close to vital organs. That was when Connah’s family learned that he had only a few more months to live. According to Debbie Broom, Connah’s mother, “A doctor told us to take Connah home and enjoy our remaining time with him.”

The family then turned to photodynamic therapy (PDT), a treatment proven to be effective in killing cancer. Connah’s treatment consisted of taking a pill containing a photosensitizing agent and then activating this agent with light. A powerful reaction was then initiated, which killed the cancerous cells while preserving the surrounding healthy tissue. Amazingly, after ten months of PDT  treatment, ten of Connah’s eleven tumours have now disappeared. “This is the one miracle in my entire career,” said Connah’s GP, Dr. Eamon Jessop, “He’s doing incredible well, it’s staggering.” To hear Connah’s story, please watch the video below:

Connah from Matt Hunt on Vimeo.

Ondine CEO, Carolyn Cross, Survives Plane Crash: “I Am More Dedicated To PDT Than Ever”

Update: Carolyn would like to thank everyone for their well wishes. She is currently at home recovering from knee surgery and we expect her to make a full recovery soon. Please send donations to the family of the pilot, Luc Fortin, to support his 16-month old daughter –

Miracles really do happen. On Thursday October 27th, Carolyn Cross (our CEO, Chairman, and dear friend) survived a deadly plane crash. On a chartered flight headed to Kelowna, Carolyn knew something wasn’t right when the pilot told passengers there was an oil leak and they were returning to the airport. “I looked at his hands and they were shaking, trembling,” Carolyn said in an interview from her hospital bed, “At that moment I knew we were going to die.” Carolyn then calmly took out her phone and began typing out farewell messages to her three young kids, “Something that they would remember me by, that I could have peace that I had said my goodbyes.”

Seconds later, Carolyn’s plane crashed on a busy road about 900 meters short of the runway. “We crashed and I immediately looked outside because I was at a door window and it was full of flames outside. So I couldn’t go out. It smelled full of gasoline….I went to get up and I could not walk. It was as if I had no legs, as if they were blown off. And I thought of my children, and God and the universe gave me the energy and I got up to the door. I said I don’t know what I am going to do now because I can’t get out of the plane, my legs, I can’t get out of the plane.”

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Photodynamic Therapy– Is Selective Damage Really that Selective?

Why doesn’t photodynamic therapy (PDT) cause any noticeable damage to human tissue? After all, the reaction causes damage to the bacterial membrane, and human cells have membranes as well.

This was a topic that really grabbed my attention when I first learned about photodynamic therapy.   How is it possible that with the creation of highly reactive molecules are we only limiting cellular destruction to bacterial cells? Although there may be a few different answers to this question, the primary solution is that we are not. Don’t be afraid and swear off photodynamic therapy right away, here me out first. Photodynamic therapy is primarily used as a treatment option for cancers. This treatment is used on cancerous tumours formed in esophageal cancer, lung cancer, skin cancer, as well as many different types. The photosensitizer is accumulated in the tumour either by direct injection or utilizing mutations of the cancerous cells that concentrate the photosensitizer inside the cell. After light is applied, the tumour cells are damaged, but the healthy cells are not greatly harmed. Why? One trait of a cancerous growth is the mutation of certain DNA repair enzymes. (Have a look at this Wikipedia article to give you a small background on DNA repair enzymes) These repair enzymes are responsible for fixing oxidative damage problems caused by free radicals. Scientific researchers, knowing this small fact about most cancerous tumour cells, use PDT and reactive oxygen species to their advantage. A healthy human cell can take some free radical “abuse”, but a tumour cell can only take so much until the cell dies. This fact, coupled with selective photosensitizer accumulation within tumour cells, makes PDT an excellent treatment option in some forms of cancer.

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Study Shows Increased Effectiveness Of Light-Activated Antimicrobial Agents Against MRSA

Many bacteria capable of causing life-threatening infections are now resistant to a wide range of antibiotics.  It is essential, therefore, that alternatives to antibiotics are developed for use in the prevention and treatment of such infections. Light-activated antimicrobial agents (LAAAs) are one possible new approach to this problem. LAAAs are compounds that display no antimicrobial activity in the dark but, when exposed to light of a certain wavelength, can kill microbes in the vicinity.  One of the essential attributes of any antimicrobial agent, including a LAAA, is that it be effective at low concentrations so as to reduce the risks of any toxicity to the patient.

The new LAAAs as seen through a very powerful electron microscope. The diameter of each particle is approximately 0.000000005 metre.

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