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Traitement thérapeutique LED : AMWC Monaco 2016: Biofilm & Light - Pr Patrizia d'Alessio

AMWC Monaco 2016: Biofilm & Light - Pr Patrizia d'Alessio

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Biofilm Light Pr d'Alessio AMWC Monaco 2016
Biofilm Light Pr d'Alessio AMWC Monaco 2016

Les formes de résistance des infections posent un problème de santé publique de plus en plus crucial notamment avec l’augmentation de résistance aux antibiotiques.

Parmi les formes les plus coriaces, le Biofilm est surement un enjeu de taille pour les combattants que nous sommes.

A travers l’histoire du bio-film, le Pr Patrizia d'Alessio nous emmène sur un chemin innovant.

C’est par la compréhension des différentes interactions des germes et de leur milieu hote, des autres organes de notre physiologie; In fine d'un Cross–Talk trés élaboré que nous pourrions négocier avec ce Fléau Infectieux.

Décoder ce langage c’est pouvoir y intéresser de façon dédiée notre arsenal photonique en biomodulation.

© M Pelletier-Aouizerate

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Resistance infections is a public health problem crucial increasingly especially with more and more antibiotic resistance.

Among the toughest forms Biofilm is certainly a major issue for the fighters that we are.

Through the history bio-film, Prof. Patrizia d'Alessio takes us on an innovative way.

Understanding the different interactions of bacteria and their host environment, and between the other organs of our physiology: In Fine A highly developed Cross-Talk that we could deal with this scourge Infectious.

Decode this language allows selectively invest in our Photonics arsenal PBM

© M Pelletier-Aouizerate



Patrizia d’Alessio, MD PhD


Biofilms are the most common form of habitat of microorganisms constituting 80% of the microbial biomass of the planet. In biofilms, bacterial cells are maintained inside a polymeric matrix composed of exopolysaccharides, proteins and nucleic acids. Their development is initiated by extracellular signals of the environment or by bacterial cells themselves. Biofilms can build up within a few hours. The biofilm matrix is highly hydrated and contains up to 97% water. In water, the structure of biofilms is influenced by light.
It is known that blue light is an anti-microbial agent via several mechanisms including SOD stimulation with consequent disruption of biofilms through ROS. Light can also act on bacteria in photodynamic fashion using ex gr intrinsic porphyrins.




Material and methods
From mouth to colon, microflora populating the gut is organized in biofilms in humans. Biofilms shelter bacteria from the host immune system, dessication, antibiotics and antiseptics. One of the most accessible human biofilms is the dental plaque, which is reconstituted day after day. Oral infections become more and more difficult to eradicate due to increased resistance to antiseptics and antibiotics. An alternative unspecific mechanism consists of using Photo Dynamic Therapy (PDT). In presence of photosensitizer (nontoxic dye) and light, the generation of oxygen species is able to damage bacterial structures and exert an antiseptic effect.




PDT has been shown to be useful in the treatment of periodontal disease by disrupting biofilms from the root surface of teeth. The dyes shown to be active with low power lasers are methylene blue, toluidine blue, malachite green or indocyanine green at the proper wavelength they induce free radicals and singlet oxygen which are toxic to bacteria.




Light has been used as therapy since the antiquity. Once forgotten, it was rediscovered at the beginning of the XXth century. Photosensitizers must be non toxic to host cells and present toxicity only after activation by light. They must remain excited long enough to lead to the production of cytotoxic species able to kill bacteria.
In summary, light, photsensitizer and oxygen are the three major actors of phototherapy. They can be used to affect biofilms present in the oral and gut mucosa hosting microbiome.



Biblio Biofilm Part: 2


1 - Adjunctive application of antimicrobial phototherapy dynamic in non surgical periodontal treatment: a Review of literature.
Takeshi Kikuchi and Al …International journal of molecular science 2015, 16

2-The effects of blue light on the biofilm formation and disruption of staphylococcus aureus
Kayla L. Fricke Faculty of Baylor university Thesis (Texas)


Biblio Biofilm Part: 3

Treatment of chronic Periodontitis by laser led and PDT Light:
An In Vivo Study (Research Laser 2012)Dr G Karakitsos and al

Finding Beauty in Barcteria: Biofilms in the Vermilon River
Linda Grashoff (Living I the vermilion River Water shed)

Porphyrin and non photoporphyrin Photosensitizers in Oncology: Preclinical and clinical advances in photodynamic therapy
Aisling E O Connor, William M Gallager and Al
Photochemistry and Photobiology, 2009, 85:1053-1074

Quantum Yield of the photosensitized Formation of the lowest
Electronically existed single state of molecular oxygen in solution
Francis Wilkinson Philip Ellman, Alberta B Ross

Phototoxic effect of Blue light on the Planktonic and Biofilm state of Anaerobic Periodontal Pathogens
Hyun-Hwa, Jae- Kwan Lee, Heung –Sic Um and Al.
Journal Periodontal Implant Sci 2013; 43:72-78

Influence of Blue Light on streptococcus mutans reorganization in Biofilm
Daniella Chebath Taub, Doron Steinberg and Al
Journal of Photochemistry and Photobiology B: Biology 116
(2012) 75-78

Antimicrobial and Dynamic Phototherapy on dental Plaque:
A systematic review of the literature
G C Santin, D.S.B Oliveira and Al
Hindawi Publishing Corporation Vol 2014 Article ID 824538

Light availability affects stream Biofilm Bacterial Community, composition and function but not diversity
Karoline Wagner, Katharina Bessemer
Environmental Microbiology 2015 17 (12), 5036-5047