This study aimed to develop microemulsions using poloxamer 124 as a surfactant to improve the skin penetration of finasteride and to investigate the skin penetration pathways of these microemulsions by colocalization techniques using confocal laser scanning microscopy (CLSM). The prepared finasteride-loaded microemulsions had average particle sizes ranging from 80.09 to 136.97 nm with particle size distributions within acceptable ranges and exhibited negative surface charges. The obtained microemulsions could significantly increase the skin penetration of finasteride compared to a finasteride solution. According to the skin penetration pathway evaluation conducted with CLSM, the microemulsions were hair follicle-targeted formulations due to penetration via the transfollicular pathway as a major skin penetration pathway. Additionally, this study found that the microemulsions also penetrated via the intercluster pathway more than via the intercellular pathway and transcellular pathway. The intercluster pathway, intercellular pathway, and transcellular pathway were considered only minor pathways.

Background/Objectives: The purpose of this study was to create bile acid-containing liposomes to improve methotrexate blood-brain barrier penetration and to assess the liposome transportation mechanism across the blood–brain barrier. Methods: The improvement of liposome penetration was investigated utilizing human brain microvascular endothelial cells in an in vitro blood-brain barrier model. Using confocal laser scanning microscopy (CLSM) and flow cytometry, liposomes were labeled with fluorescent phospholipids to facilitate their passage across the blood–brain barrier. Results: The produced liposomes with bile acid exhibited a negative surface charge and an average particle size of between 30 and 148 nm. According to an in vitro blood-brain barrier penetration study, the methotrexate penetration was increased by liposomes containing 1% glycocholic acid but not by liposomes containing taurocholic acid. For transport pathway evaluation across the blood-brain barrier of these liposomes, CLSM revealed that fluorescent liposomes were present inside cells treated with specific endocytosis inhibitors, indicating that the cellular internalization of the particles was not involved in endocytosis. Conclusions: Liposomes supplemented with 1% glycocholic acid could enhance the penetration of methotrexate across the blood-brain barrier, while taurocholic acid could not. The transport of liposomes with 1% glycocholic acid across the blood-brain barrier occurs via the transcellular pathway through which it penetrates cells. In contrast, the paracellular pathway was a minor pathway.

Electrospinning of Polycaprolactone Nanofibrous Scaffolds Containing Folic Acid for Nerve Tissue Engineering

This study developed an alcohol-free, sugar-free oral spray containing stingless bee propolis (SBP) and mangosteen pericarp (MP) extracts with desirable physicochemical properties and stability. The formulations were evaluated for pH, viscosity, and SBP and MP extract content using high-performance liquid chromatography. Antioxidant and antimicrobial activities were assessed using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay and antibacterial testing against Streptococcus pyogenes. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was employed to assess the cytotoxicity of the spray to human gingival fibroblasts. Microbial contamination and stability were also examined. The formulations, which contained up to 25 mg of each extract, had a pH range of 6.02–6.54 and viscosities of 0.46–1.19 mPa·s, demonstrating Newtonian flow. The SBP and MP extract contents of the formulation ranged from 99.94% to 102.27%. The antioxidant inhibition rates were 62.04%–84.62%, while the antimicrobial activity was observed at a 50% concentration. Cytotoxicity tests confirmed over 50% cell viability in oral mucosal cells after 15 seconds of exposure. Microbial contamination met safety standards, and the formulations remained stable for 6 months under both normal and accelerated conditions, with the α-mangostin content ranging between 96.12% and 98.76%. This study successfully developed a novel stable oral spray incorporating MP and SBP extracts with favorable organoleptic properties, antioxidant potential, and antimicrobial efficacy, indicating its potential for oral health applications.