Thermoresponsive Hydrogel-Loading Aluminum Chloride Phthalocyanine as a Drug Release Platform for Topical Administration in Photodynamic Therapy

Abstract

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.

Design and Optimization of Stimuli-responsive Emulsion-filled Gel for Topical Delivery of Copaiba Oil-resin

“…In this process, the topical release platform makes therapeutic agents available longer for cutaneous permeation effects. 10 The rheological outcomes complied with the mechanical properties also showed advantages for the PHY-ECOs composed of the lower F127 and CO ratios. These PHY-ECOs exhibited high variation in viscosity between 5.0°C (storage temperature) and 35.0°C (skin Fig.…”

“…Stimuli-responsive emulsion-filled gels composed of F127, C934P and CO mixture (PHY-ECO) aim to combine the benefits of natural therapeutic agents with an efficient performance of a smart drug delivery system. 10,11 F127, when used in moderately concentrated solutions (above 15 % w/w), allows the thermosensitive micellar gel formation that can be stimulated by skin temperature. Additionally, it can act as a skin permeation promoter of natural chemotherapeutic agents contained in CO. 10 The combination of F127 micelles and C934P forms a polymeric lattice (gelled continuous phase) with micelle-rich interstices (emulsion-filled gel), as shown in Fig.…”

“…4B) of "soft gel". 10,11 The sol-gel transition temperature indicates the thermodynamics processes that allows changes in the micellar organization from pre-ordered to cubic state, and the "hard gel" is formed. 10 The absence of G' and G" crossover demonstrates the inexistence of a critical gel point.…”

“…10,11 The sol-gel transition temperature indicates the thermodynamics processes that allows changes in the micellar organization from pre-ordered to cubic state, and the "hard gel" is formed. 10 The absence of G' and G" crossover demonstrates the inexistence of a critical gel point. Thus, the inflection represents an increased dehydration of the hydrophilic chains, increased hydrophobic interactions among PPO groups, and a rise in simultaneous interactions between the micro-droplets and the interfaces layers.…”

Increased photoluminescence and photodynamic therapy efficiency of hydroxyapatite-β-cyclodextrin-methylene blue@carbon powders with the favor of hydrogen bonding effect

“…The value of k 1 /C M is determined to compare the generation efficiency for single MB molecule released from HAp-MB@C140 and ( 1) HAp-CD2-MB@C140. In comparison with that of HAp-MB@C140, about four-fold increase in PDT efficiency is observed for MB released from HAp-CD2-MB@C140, producing singlet oxygen molecules in an efficient way, relative to other different nanoplatforms [47,55,[57][58][59] (Table S4). When increasing the supernatant addition of MB, PDT efficiency increases slightly for HAp-CD2-MB@C140 due to the formation of MB aggregations, causing reduction in the generation ratio of singlet oxygen.…”