Photodynamic potential of hexadecafluoro zinc phthalocyanine in nanostructured lipid carriers: physicochemical characterization, drug delivery and antimicrobial effect against Candida albicans.

This study aims to develop and characterize NCL loaded with ZnF16Pc (Pc) for application in antimicrobial photodynamic therapy. For the development of the NLC, the fusion-emulsification technique followed by sonication was applied. NLC and Pc-NLC were characterized in terms of mean diameter (Dm.n), polydispersity index (PdI), zeta potential (ZP), encapsulation efficiency (%EE), transmission electron microscopy (TEM), differential scanning (DSC), photobleaching and singlet oxygen generation in cellular systems (SOSG), and in vitro release assays performed by the beaker method, using dialysis membranes. Cell viability was performed by colony forming units (CFU/mL). The mean size of NLC and Pc-NLC was 158 nm ± 1.49 to 161.80 nm and showed PdI < 0.3 and ZP between -17.8 and -19.9, and stable during storage time (90 days). The TEM presented spherical particles, the Pc-NLC promoted the encapsulation of 75.57% ± 0.58. DSC analysis confirmed that there was no incompatibility between Pc and NLC. The analysis of the photodegradation profile proved to be photostable after encapsulation and this corroborates the data obtained by SOSG. In vitro release showed controlled and prolonged release. PDT Pc-NLC exhibited greater antifungal effect against C. albicans (3 log10 reduction) than Pc-NLC without light (1 log10 reduction). NLC can be an alternative to the application of Pc and improve the effect during PDT treatment.

Prospective application of phthalocyanines in the photodynamic therapy against microorganisms and tumor cells: A mini-review.

Phthalocyanines are second-generation photosensitizers with photophysical and photochemical properties improved, in comparison to the first-generation. Also, these have shown to be phototoxic against several types of microorganisms and tumor cells. However, challenges such as low solubility in the physiological environment make its single administration unfeasible. Therefore, this review discusses a unique combination of phthalocyanine-loaded in drug delivery carriers for photodynamic therapy in different pathologies' treatment, including nanoemulsion, liposomes, and lipid nanoparticles in an attempt to overcome low solubility drawback. Furthermore, the latest advances to elucidating its mechanisms of action are shown. Subsequently, the manuscript was divided into ten different types of phthalocyanines for medical applications, with a description of their definitions and applications, summarizing the latest preclinical results founded in recent literature.

Phthalocyanine-loaded nanostructured lipid carriers functionalized with folic acid for photodynamic therapy.

Breast cancer is a serious public health problem that causes thousands of deaths annually. Chemotherapy continues to play a central role in the management of breast cancer but is associated with extreme off-target toxicity. Therefore, treatments that directly target the tumor and display reduced susceptibility to resistance could improve the outcome and quality of life for patients suffering from this disease. Photodynamic therapy is a targeted treatment based on the use of light to activate a photosensitizer (PS) that then interacts with molecular oxygen and other biochemical substrates to generate cytotoxic levels of Reactive Oxygen Species. Currently approved PS also tends to have poor aqueous solubility that can cause problems when delivered intravenously. In order to circumvent this limitation, in this manuscript, we evaluate the potential of a phthalocyanine-loaded nanostructured lipid carrier (NLC) functionalized with folic acid (FA). To prepare the FA labelled NLC, the polymer PF127 was first esterified with FA and emulsified with an oil phase containing polyoxyethylene 40 stearate, capric/caprylic acid triglycerides, ethoxylated hydrogenated castor oil 40 and the PS zinc phthalocyanine. The resulting PS loaded FA-NLC had a hydrodynamic diameter of 180 nm and were stable in suspension for >90 days. Interestingly, the amount of singlet oxygen generated upon light activation for the PS loaded FA-NLC was substantially higher than the free PS, yet at a lower PS concentration. The PS was released from the NLC in a sustained manner with 4.13 ±â€¯0.58% and 27.7 ±â€¯3.16% after 30 min and 7 days, respectively. Finally, cytotoxicity assays showed that NLC in the concentrations of 09.1 µM of PS present non-toxic with >80 ±â€¯6.8% viable and after 90 s of the light-exposed the results show a statistically significant decrease in cell viability (57 ±â€¯4%). The results obtained allow us to conclude that the functionalized NLC incorporated with PS associated with the PDT technique have characteristics that make them potential candidates for the alternative treatment of breast cancer.