Photodynamic therapy utilizing multiple duty cycle light modulation
AssigneeAdvanced Photodynamic Technologies, Inc.
InventorsMerrill Biel, Chester Sievert, Mark Peterson
Life of this patent
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Abstract
A method of photodynamic disruption of target cells within a target cell site wherein the target cells are associated with one or more of a sterilization procedure, a biofilm eradication procedure, a sterilization procedure of a medical prosthesis, a treatment of an infection at a tissue site, eradication of cancer cells and a fluid or food decontamination process. Surface acting agents such as benzalkonium chloride or polymyxin B sulfate or both may be utilized. A controllable light source capable of delivering light at a plurality of duty cycles is utilized to cause photoactivation of the photosensitive material resulting in degradation of target cells within the site.
Claims30
A method of photodynamic disruption comprising:
- identifying a target cell site;
- providing a photosensitive material to the target cell site;
- providing a controllable light source capable of delivering light at a plurality of duty cycles;
- periodically illuminating target cells within the target cell site with light from the light source at a first duty cycle;
- and
- during periods of illumination associated with the first duty cycle, pulsing the light source at a second duty cycle so as to cause photoactivation of the photosensitive material resulting in degradation of target cells within the site.
A method of photodynamic disruption comprising:
- identifying a target cell site;
- providing a photosensitive material to the target cell site;
- during a light interval spanning a first period of time, illuminating the target cell site with light from a light source having wavelengths between 450 nm to 900 nm, said light source being repeatedly pulsed ON and OFF at a first duty cycle to provide a periodic light dose to the organism site during the first period of time of between 0.001 J/cm2 to 10 J/cm2;
- during a dark interval, substantially reducing light delivered to the target cell site by the light source for a second period of time of more than 100 seconds;
- and
- repeating the light interval and then the dark interval during a treatment session to define a second duty cycle, and illuminating the target cell site at the first and second duty cycles during a treatment session to provide a cumulative light dose to the target cell site of between 2 to 400 J/cm2 to cause target cell disruption.
Dependencies are inferred from the claim text.