Preparation of water-in-oil (W/O) cinnamaldehyde microemulsion loaded with epsilon-polylysine and its antibacterial properties

Fe3O4-Based Nanospheres with High Photothermal Conversion Efficiency for Dual-Effect and Mild Biofilm Eradication against Periodontitis

Periodontitis, a chronic inflammatory oral disease resulting from plaque biofilms, affects about 743 million individuals worldwide. However, the efficacy of current treatments is hampered by challenges in delivering antibiotics to recalcitrant oral biofilms and bacterial resistance, thereby impeding successful treatment of infectious diseases. To address the issues, an antibacterial photothermal material was designed, comprising a spherical structure of zinc oxide (ZnO) wrapped with triiron tetraoxide (Fe3O4). The outer layer of the material adsorbed epsilon-polylysine (EPL) by electrostatic action, ultimately leading to the fabrication of Fe3O4/ZnO/EPL nanoparticles (FZE NPs). The Fe3O4 core endowed the nanoparticles with efficient photothermal properties, facilitating the dispersion of dense biofilms, which dramatically promoted the adsorption and penetration of ZnO and EPL into the biofilms to effectively kill bacteria in biofilms in vitro with enhanced sterilization ability. Additionally, upon dissolution in aqueous media, EPL acts as a positively charged antimicrobial peptide that adsorbs onto the surface of negatively charged bacterial membranes, thereby effectively modulating inflammatory responses. In order to ascertain the efficacy of FZE NPs, an investigation was conducted into their antimicrobial effects against the periodontitis-associated pathogen Porphyromonas gingivalis (P. gingivalis) in vitro. Furthermore, the antiperiodontitis potential of FZE NPs was evaluated in Sprague-Dawley (SD) rats of ligamentous periodontitis. In addition, toxicity evaluations indicated that the material had an acceptable biosafety profile in vitro and in vivo. In summary, the nanospheres (FZE NPs) represent a promising therapeutic strategy for the treatment of periodontitis.

Advancements in the Transdermal Drug Delivery Systems Utilizing Microemulsion-based Gels

Microemulsion gel, as a promising transdermal nanoparticle delivery system, addresses the limitations of microemulsions and enhances their performance in drug delivery and release. This article aims to discuss the advantages of microemulsion gel, including improved drug bioavailability, reduced drug irritation, enhanced drug penetration and skin adhesion, and increased antimicrobial properties. It explores the methods for selecting microemulsion formulations and the general processes of microemulsion preparation, as well as commonly used oil phases, surfactants, and co-surfactants. Additionally, the biomedical applications of microemulsion gel in treating conditions, such as acne and psoriasis, are also discussed. Overall, this article elucidates the significant potential of microemulsion gel in topical drug delivery, providing insights into future development and clinical applications.

Assessment of antimicrobial activity of melittin encapsulated in bicontinuous microemulsions prepared using renewable oils

The objective of this study is to demonstrate that melittin, a well-studied antimicrobial peptide (AMP), can be solubilized in an active form in bicontinuous microemulsions (BMEs) that employ biocompatible oils. The systems investigated consisted of Winsor-III and -IV BME phases composed of Water/Aerosol-OT (AOT)/Polysorbate 85/isopropyl myristate and a Winsor-IV BME employing Polysorbate 80 and limonene. We found that melittin resided in an α-helix-rich configuration and was in an apolar environment for the AOT/Polysorbate 85 Winsor-III system, suggesting that melittin interacted with the surfactant monolayer and was in an active conformation. An apolar environment was also detected for melittin in the two Winsor-IV systems, but to a lesser extent than the Winsor-III system. Small-angle X-ray scattering analysis indicated that melittin at a concentration of 1.0 g/Laq in the aqueous subphase of the Winsor-IV systems led to the greatest impact on the BME structure (e.g., decrease of quasi-periodic repeat distance and correlation length and induction of interfacial fluidity). The antimicrobial activity of the Polysorbate 80 Winsor-IV system was evaluated against several bacteria prominent in chronic wounds and surgical site infections (SSIs). Melittin-free BMEs inhibited the growth of all tested bacteria due to its oil, limonene, while the inclusion of 1.0 g/Laq of melittin in the BMEs enhanced the activity against several bacteria. A further increase of melittin concentration in the BMEs had no further enhancement. These results demonstrate the potential utility of BMEs as a delivery platform for AMPs and other hydrophilic and lipophilic drugs to inhibit antibiotic-resistant microorganisms in chronic wounds and SSIs.