Artificial semi-rigid tissue sensitized with natural pigments: Effect of photon radiations

Background: A new approach for evaluating the optical penetration depth and testing its validity with Monte Carlo simulations and Kubelka-Munk theory is used for artificial semi-rigid tissue sensitized with natural pigments. Photodynamic therapy is a promising cancer treatment in which a photosensitizing drug concentrates in malignant cells and is activated by visible light at certain wavelength. Materials and Methods: Cheap artificial semi-rigid tissue incorporated with scattering and absorbing materials along with some other composites comparable to normal human tissue has been performed. The optical parameters as measured with different conditions and calculated with various techniques are investigated. Results: The probability of interaction of light with tissue is very high when exposed to light in presence of Cichorium pumilum and RBCs followed by photohemolysis or/and photodegradation. The optical penetration depth calculated by linear absorption coefficient ranges from 0.63 to 2.85 mm is found to be comparable to those calculated using Kubelka-Munk theory or Monte Carlo simulation (range from 0.78 to 2.42 mm). The ratio of absorption to the scattering is independent of thickness and decreases with increasing irradiation time. Moreover, the optical parameters as well as their ratios are in very good agreement in the two approaches of calculation. The values of absorption and scattering coefficients are independent of thickness. Furthermore, the average photon ranges in the samples containing no scattering and absorbing materials are about three times greater than those samples containing scattering materials. Conclusion: Our results suggest that light propagation with optical properties presented in this work could be applicable in diagnostic and therapeutic of the human biological tissue for photodynamic therapy

Boosting the in-vitro effectiveness of photodynamic therapy on MCF-7 breast cancer cells with encapsulated malachite green by silica nanoparticles

Photodynamic therapy (PDT) is a promising cancer treatment strategy utilizing photosensitizers (PS) and light to generate singlet oxygen, with Malachite Green (MG) showing high singlet oxygen quantum yield. Effective delivery of MG to the target tissue remains a key challenge. Encapsulation techniques have been investigated to improve PS delivery, minimize PS leakage, inhibit diaphorase-induced reduction, and mitigate PS-related toxicity. Silica nanoparticles (SiNPs) offer favorable characteristics for drug delivery in PDT and serve as promising delivery carriers. In this study, SiNPs were synthesized and employed as carriers for MG. The size and shape of nanoparticles were determined using Transmission Electron Microscopy (TEM). A range of concentrations of MG were applied to MCF-7 breast cancer cells in order to evaluate the cytotoxicity of both naked and encapsulated MG. This helped identify the most effective concentrations and exposure durations required to induce damage under red laser light (Intensity ∼110 mW/cm2). The results indicated that SiNPs-encapsulated MG exhibited superior efficacy compared to naked MG, with a concentration efficacy increase of +50 % and an exposure time efficacy increase of +45 %. This underlines the enhanced capability of encapsulated MG to eliminate MCF-7 cells when compared to naked MG. The application of synthesized SiNPs for MG delivery improved the effectiveness of photodynamic therapy by augmenting MG bioavailability in target cells

Magnetic nanoparticles sensitize MCF-7 breast cancer cells to doxorubicin-induced apoptosis

<p>Abstract</p> <p>Background</p> <p>Resistance of breast cancer cells to the available chemotherapeutics is a major obstacle to successful treatment. Recent studies have shown that magnetic nanoparticles might have significant application in different medical fields including cancer treatment. The goal of this study is to verify the ability of magnetic nanoparticles to sensitize cancer cells to the clinically available chemotherapy.</p> <p>Methods</p> <p>The role of iron oxide nanoparticles, static magnetic field, or a combination in the enhancement of the apoptotic potential of doxorubicin against the resistant breast cancer cells, MCF-7 was evaluated using the MTT assay and the propidium iodide method.</p> <p>Results</p> <p>In the present study, results revealed that pre-incubation of MCF-7 cells with iron oxide nanoparticles before the addition of doxorubicin did not enhance doxorubicin-induced growth inhibition. Pre-incubation of MCF-7 cells with iron oxide nanoparticles followed by a static magnetic field exposure significantly (<it>P</it> < 0.05) increased doxorubicin-induced cytotoxicity. Sensitization with pre-exposure to the magnetic field was dose-dependent where the highest cytotoxicity was seen at 1 tesla. Further experiments revealed that the anti-proliferative effect of this treatment procedure is due to induction of apoptotic cell death.</p> <p>Conclusions</p> <p>These results might point to the importance of combining magnetic nanoparticles with a static magnetic field in treatment of doxorubicin-refractory breast cancer cells.</p