Phthalocyanine aluminum chloride
(Pc) is a clinically viable photosensitizer
(PS) to treat skin lesions worsened by microbial infections. However,
this molecule presents a high self-aggregation tendency in the biological
fluid, which is an in vivo direct administration
obstacle. This study proposed the use of bioadhesive and thermoresponsive
hydrogels comprising triblock-type Pluronic F127 and Carbopol 934P
(FCarb) as drug delivery platforms of Pc (FCarbPc)-targeting topical
administration. Carbopol 934P was used to increase the F127 hydrogel
adhesion on the skin. Rheological analyses showed that the Pc presented
a low effect on the hydrogel matrix, changing the gelation temperature
from 27.2 ± 0.1 to 28.5 ± 0.9 °C once the Pc concentration
increases from zero to 1 mmol L–1. The dermatological
platform showed matrix erosion effects with the release of loaded
Pc micelles. The permeation studies showed the excellent potential
of the FCarb platform, which allowed the partition of the PS into
deeper layers of the skin. The applicability of this dermatological
platform in photodynamic therapy was evaluated by the generation of
reactive species which was demonstrated by chemical photodynamic efficiency
assays. The low effect on cell viability and proliferation in the
dark was demonstrated by in vitro assays using L929
fibroblasts. The FCarbPc fostered the inhibition of Staphylococcus aureus strain, therefore demonstrating
the platform’s potential in the treatment of dermatological
infections of microbial nature.
Safranine-O (Sf) is a photosensitizer (PS) displaying a remarkable potential for photodynamic therapy (PDT). In this work, we have used the combination of Sf with F127 Pluronic and Carbopol (C934P) to obtain a stimuliresponsive hydrogel (SR-Sf). This thermoresponsive-photoactive nanostructured system was prepared by two different methods: direct addition (DA) and solid dispersion (SD). Both SR-Sf have had their physical and chemical properties evaluated for veterinary applications, especially considering their ability to be used as a commercial product, aiming at the prophylactic or therapeutic treatment of breast gland infections. In general, the rheological and mechanical properties, as well as the sol−gel transition temperature, indicated suitable properties for using them as a topical system in veterinary (and human) applications. The ex vivo release studies showed a satisfactory permeation profile of the SR-Sf hydrogel, reaching the full length of the overall skin toward the dermis within 30 min of application (989 μm). The in vitro studies showed photodynamic inactivation using Sf-F127 with a significant reduction in isolated colonies. The in vivo case report with dairy goat demonstrated that the SR-Sf hydrogel veterinary use platform emerged as an innovative approach for the treatment of local infections without generating antibiotic residues in the milk produced.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.