Novel Techniques for Improving Anti-Cancer Efficacy via Synergistic Phototherapy

Abstract

Factors influencing the cancer therapy efficiency in both photothermal therapy (PTT) and photodynamic therapy (PDT) using nanogold particles and photosensitizers, respectively, are analyzed. In PTT, heat diffusion kinetics is used to calculate the temperature increase resulted from the nanogold absorption of light energy, whereas photochemical kinetics is used to find the efficacy of PDT, or the generation rate of reactive oxygen species. Efficacy of cancer therapy may be enhanced by combining PTT and PDT either activated by one light or two lights. For maximum PTT/PDT synergistic efficacy, the concentration of photosensitizers and nanogold required optimization, besides the wavelength of the light matching the absorption peak of PS and nanogold, and the sequential order of PTT and PDT process. External supply of either photosensitizers or oxygen concentration will significantly improve the anti-cancer efficacy via type-II PDT. Optimization is required for maximum synergic efficacy.

Recent Advances of Low-Level Light Therapy: Fundamentals, Efficacy and Applications

“…A generalized, time dependent Beer-Lambert law (BLL), the non-BRL optimal conditions, and mathematical formulas (scaling laws) have been discussed by Lin [26][27][28]. Similar to the synergic efficacy of PDT/PTT [6], far infrared light (3 to 50um) can cause the selective absorption of biological lipid bilayer membranes to enhance the overall LLLT efficacy, via the synergic activation of light/heat sensitive ion channels. Figure 1 shows the PDT efficacy versus light dose (E) and photosensitizer (PS) concentration, C 0 .…”

“…Lights (lasers and LEDs) have been used for various medical procedures such as dermatology and cosmetic surgery, wound healings, nerve stimulation, dentistry ophthalmology applications for vision corrections and corneal deceases, and many other therapeutic procedures [1][2][3]. Combining the nanoparticles, diode lasers have been also used for cancer therapy, bio-sensing, bioimaging, drug delivery, tissue engineering and diagnostics of cancer cell [4][5][6][7].…”

“…High power lights (in CW or pulsed mode) have been reviewed by Lin [1,[6][7][8][9] for photothermal therapy (PTT) and photodynamic therapy (PDT), using the light spectra of UV (200-400) um, visible (400-700) nm, near-IR (700-2900) nm, and mid-IR (3-5) um having various penetration depths which define invasive and noninvasive procedures. In contrast to PTT (with high light intensity) and PDT (with photosensitizers), low level light therapy (LLLT), or photobiomodulation (PBM) has a much lower intensity between 5 to 500 mW/cm 2 and does not require photosensitizers (PS).…”

Advances of Cancer Synergic Photo-Therapy: Kinetics and Efficacy

“…A recent review article of Yurt & Tuncel [1] reported the clinical aspects of combined photodynamic and radiotherapy synergistic effect in cancer treatment. Synergic method combining photothermal therapy (PTT) and photodynamic therapy (PDT) using nanogold particles and photosensitizers were also reported [2][3][4]. Besides the synergic methods, improvement of the efficacy of anti-cancer also include the use of nano-medicine and nanoparticles [5].…”

Modeling the Kinetics, Dynamic Profiles and Strategies for Optimal Efficacy of Photo-Polymerization in Thick Polymers

“…However, type II photoinitiator requires a coinitiator and often accelerant species to generate efficiently a sufficient number of radicals for photopolymerization. The kinetic of PPS and its clinical applications for anti-cancer [10][11][12][13] and corneal crosslinking (CXL) [14,15] have been recently presented. We have presented modeling the efficacy profiles of UV-light activated CXL, in which the treated cornea has a much smaller thickness (approximately 500 um, or 0.05 cm) than most polymer systems, approximately 1.0 cm.…”