Associate Member of the Staff
Director, Applied Molecular Photomedicine Laboratory
Department of Applied Oral Health Sciences
University of Athens, Greece, D.D.S., 1984, Dentistry
University of Munich, Germany, Ph.D., 1989, Biology of Oral Cancer
University of London, UK, M.Sc., 1991, Experimental Oral Pathology
The Applied Molecular Photomedicine Laboratory (AMPL) was founded at The Forsyth Institute in 2003 by Dr. Nikos Soukos with the support of an award from the National Institutes of Dental and Craniofacial Research (NIDCR). AMPL is dedicated to exploring the full potential for the use of light in oral medicine and surgery. It is a multi-disciplinary translational research environment, in which scientists, clinicians and engineers have developed a productive and successful partnership. AMPL serves as a two-way transfer between basic science and patient care seeking to bridge the gap between them by developing hypotheses based on findings obtained from both basic and clinical research. AMPL aligns its research along two original scientific themes that put great emphasis on establishing principles for: 1) prevention, control and/or treatment of oral infectious diseases (tooth decay, gum disease, dental pulp disease); and 2) detection and treatment of early oral cancer.
A few projects currently under way include the following:
Selective phototargeting of microorganism in dental plaque
We have proposed the use of visible (blue) light as a bactericidal agent in vivo to eliminate dental plaque pathogens by activating their endogenous porphyrins. The selective inhibition of the growth and metabolism of these species may lead to biofilm disruption and eventually to decreasing the pathogenic bacterial load. The result will be the prophylactic stabilization of the normal microbial composition of the plaque, even under conditions that may otherwise predispose a site to periodontitis.
Periodontitis is a destructive chronic inflammatory condition of the supporting structures of the teeth that arises as the result of the interaction of microorganisms and their products in dental plaque (periodontal biofilm) with host defense mechanisms. Our goal is to develop a photochemotherapeutic system for the treatment of periodontitis. A photoactive compound or "photosensitizer" could be introduced into the dental pocket followed by red light illumination via an optical fiber (photodynamic therapy or "PDT"). This technique would offer the following advantages in the hypothetical case of its in vivo application: (a) rapid application of the drug in the dental pocket and rapid bacterial killing after a short time of exposure of the dental pockets to light; (b) killing could easily be confined to the lesion by restricting irradiation to this region, so that microflora at other sites would remain intact; and (c) light would be delivered topically, rapidly and non-invasively. Our current work is focused on the photosensitization of periodontal biofilms in vitro using a series of different photosensitizers.
Endodontic failures are caused by the proliferation of residual bacteria that are left behind within the root canal due to the complexity of the root canal system that makes complete debridement with instrumentation and irrigation alone almost impossible. More than two million root canal retreatments due to residual microorganisms are performed yearly in the US. PDT may be an adjunctive procedure to kill residual root canal bacteria after their sensitization with a photoactive drug and their subsequent exposure to light. We envision the application of PDT in clinical practice as follows: The photoactive drug will be applied in the root canal system after instrumentation is complete for a short time (up to five minutes) and will strongly bind to the negatively charged matrix and to bacteria. Then a fiber optic will be used to deliver red light from a diode laser to irradiate microbial biofilms on the root canal surface as well as in the dentinal tubules. The entire root canal system will be exposed to light simultaneously for five minutes.
The Nano-Photo-Medicine Initiative
Recently, we launched the "Nano-Photo-Medicine Initiative" together with the Department of Pharmaceutical Sciences at Northeastern University. The vision behind this intitiative is to integrate Photomedicine with Nanotechnology. This will result in the development of multi-functional systems and smart drugs, which will target only the diseased site in the mouth (cancer or infection). The goal is to create simple, accurate, minimally-inasive, light-guided (optically tracked) and light-activated diagnostic and thearpeutic procedures using "nano" structures or "nano" machines that are compatible with living tissues and can safely operate at the level of molecules and atoms.
Ng R, Singh F, Papamanou DA, Song X, Patel C, Holewa C, Patel N, Klepac-Ceraj V, Fontana CR, Kent R, Pagonis TC, Stashenko PP, Soukos NS. Endodontic photodynamic therapy ex vivo. J Endod. 2011 Feb; 37(2):217-22
Soukos NS, Goodson JM. Photodynamic therapy in the control of oral biofilms. Periodontal 2000. 2011 Feb;55(1):143-66
Pagonis TC, Chen J, Fontana CR, Devalapally H, Ruggiero K, Song X, Foschi F, Dunham J, Skobe Z, Yamazaki H, Kent R, Tanner AC, Amiji MM, Soukos NS. Nanoparticle-based endodontic antimicrobial photodynamic therapy. J Endod. 2010 Feb;36(2):322-8.
Xu Y, Young MJ, Battaglino RA, Morse LR, Fontana CR, Pagnois TC, Kent R, Soukos NS. (2009) Endodontic antimicrobial photodynamic therapy: safety assessment in mammalian cell cultures. J. Endod. 35(11):1567-1572.
Fontana CR, Abernethy AD, Som S, Ruggiero K, Doucette S, Marcantonio RC, Boussios CI, Kent R, Goodson JM, Tanner AC, Soukos NS. (2009) The antibacterial effect of photodynamic therapy in dental plaque-derived biofilms. J. Periodontal Res. 44(6):751-759.
Fimple JL, Fontana CR, Foschi F, Ruggiero K, Song X, Pagonis TC, Tanner AC, Kent R, Doukas AG, Stashenko PP, Soukos NS. (2008) Photodynamic treatment of endodontic polymicrobial infection in vitro. J. Endod. 34(6):728-734.
Ogura M, Abernethy AD, Blissett RD, Ruggiero K, Som S, Goodson JM, Kent R, Doukas AG, Soukos NS. (2007) Photomechanical wave-assisted drug delivery in oral multispecies biofilms. World J. Microbiol. Biotechnol. 23(11):1637-1646.
Soukos NS, Som S, Abernethy A, Ruggiero K, Dunham J, Lee C, Doukas AG, Goodson JM. (2005) Phototargeting oral black-pigmented bacteria. Antimicrob. Agents Chemother. 49(4):1391-1396.
Vanja Klepac-Ceraj, PhD
Xiaoqing (Lucy) Song, MD
ThaoNgyuen Nguyen, BS
Archana Nadig, BS
Tom C. Pagonis, DDS, MS
Harvard Endodontic Residents
Ahmad Alnatour, DDS
Thao Le, DDS