Chemoenzymatic Synthesis of D-Glucitol-Based Non-Ionic Amphiphilic Architectures as Nanocarriers

Rhamnus prinoides leaf extract loaded polycaprolactone-cellulose acetate nanofibrous scaffold as potential wound dressing: An in vitro study

Rhamnus prinoides leaf contains carbohydrates, saccharides, phenolic acids, and diterpenes with antibacterial, wound-healing, and anti-inflammatory properties. In this study, Rhamnus prinoides leaf extract was successfully incorporated into polycaprolactone-cellulose acetate (PCL-CA) nanofibers through electrospinning technique for the first time. The mats' morphology, diameter, chemical, and crystalline structure were characterized. The study investigated the mats' antibacterial activity, wound healing, cytotoxicity, drug release behaviour, hydrophilicity, and water absorbency properties. The results revealed that the mats exhibited continuous, smooth, without-beads, and interconnected structures, with average fiber diameters ranging from 385 ± 21 nm to 332 ± 74 nm. The antibacterial effeciency was remarkable against S. aureus and E. coli, achieving bacterial reduction percentages exceeding 99 % at concentrations of 3 % and above against S. aureus and 5 % and above against E. coli. Cytotoxic tests showed low-cytotoxicity up to an extract concentration of 7 %. The extract release increases with an increase in concentration. In vitro wound healing assay, the mats enhanced cell migration to the wound area. Additionally, the incorporation of Rhamnus prinoides significantly improved the hydrophilicity and water absorbency of the nanofibers. Overall, the study highlights the mats' broad antimicrobial and wound healing properties with less cytotoxicity, hydrophilicity, and water absorbency, making them promising for use as wound dressings.

Optically monitoring the microenvironment of a hydrophobic cargo in amphiphilic nanogels: influence of network composition on loading and release

Amphiphilic nanogels (ANGs) are promising carriers for hydrophobic cargos such as drugs, dyes, and catalysts. Loading content and release kinetics of these compounds are controlled by type and number of hydrophobic groups in the amphiphilic copolymer network. Thus, understanding the interactions between cargo and colloidal carrier is mandatory for a tailor-made and cargo-specific ANG design. To systematically explore the influence of the network composition on these interactions, we prepared a set of ANGs of different amphiphilicity and loaded these ANGs with varying concentrations of the solvatochromic dye Nile Red (NR). Here, NR acts as a hydrophobic model cargo to optically probe the polarity of its microenvironment. Analysis of the NR emission spectra as well as measurements of the fluorescence quantum yields and decay kinetics revealed a decrease in the polarity of the NR microenvironment with increasing hydrophobicity of the hydrophobic groups in the ANG network and dye-dye interactions at higher loading concentrations. At low NR concentrations, the hydrophobic cargo NR is encapsulated in the hydrophobic domains. Increasing NR concentrations resulted in probe molecules located in a more hydrophilic environment, i.e., at the nanodomain border, and favored dye-dye interactions and NR aggregation. These results correlate well with release experiments, indicating first NR release from more hydrophilic network locations. Overall, our findings demonstrate the importance to understand carrier-drug interactions for efficient loading and controlled release profiles in amphiphilic nanogels.

Analysis and comparison of bioactive phytochemical composition and antibacterial property of two Ethiopian indigenous medicinal plants

Indigenous medicinal plants with naturally inherited antimicrobial properties are promising sources of antimicrobial agents. Two indigenous Ethiopian traditional medicinal plants (Rhamnus prinoide and Croton macrostachyus) extracted using different solvents and the yield percentage, phytochemical analysis and antimicrobial activity of the plant extracts were examined and compared. The results of this study revealed that Rhamnus prinoide leaf extract using aqueous methanol/ethanol (1 : 1) had the highest yield (15.12 %), a minimum inhibitory concentration of 0.625 mg/mL, and a minimum bactericidal concentration of 10 mg/mL against S. aureus. Croton macrostachyus leaves showed a yield of 14.7 ±0.37 %, a minimum inhibitory concentration of 40 mg/mL, and a minimum bactericidal concentration of 40 mg/mL against S. aureus and E. coli. GC-MS analysis revealed that aqueous methanol/ethanol (1 : 1) of Rhamnus prinoide and Croton macrostachyus leaf extracts were composed of bioactive carbohydrates, flavonoid acid phenols, and terpenoids, while Croton macrostachyus extract contained primarily phytol (30.08 %). The presence of bioactive compounds confirms the traditional use of these plant leaves to treat various diseases, including wounds, leading to the conclusion that they could be applied to textiles for wound dressing in future studies.

Non-ionic small amphiphile based nanostructures for biomedical applications

Self-assembly of non-ionic amphiphilic architectures into nanostructures with defined size, shape and morphology has garnered substantial momentum in the recent years due to their extensive applications in biomedicine. The manifestation of a wide range of morphologies such as micelles, vesicles, fibers, tubes, and toroids is thought to be related to the structure of amphiphilic architectures, in particular, the choice of the hydrophilic and hydrophobic parts. In this review, we look at different types of non-ionic small amphiphilic architectures and the factors that influence their self-assembly into various nanostructures in aqueous medium. In particular, we focus on the explored structural parameters that guide the formation of various nanostructures, and the ways these structures can be used in applications ranging from drug delivery to cell imaging.