The biological activity of natural plant-oil-based nanostructured lipid carriers (NPO-NLCs) can be enhanced by the encapsulation of bioactive compounds, and they in turn can improve topical delivery of the drugs. Quercetin (QR), a vital plant flavonoid, expresses antibacterial properties, and we recently showed that empty NPO-NLCs also have antimicrobial activity. The main objective of this study was to evaluate the synergetic effect of loading natural plant-oil-based nanostructured lipid carriers with quercetin (QR-NPO-NLCs) as a topical delivery system for the treatment of bacterial skin infections. Five nanostructured lipid carrier systems containing different oils (sunflower, olive, corn, coconut, and castor) were engineered. The particles’ stability, structural properties, bioavailability, and antimicrobial activity were studied. NLCs with an average size of 99%). The encapsulation of QR decreased cytotoxicity and increased the antioxidant effect of nanocarriers. An increase in antibacterial activity of the systems containing QR was demonstrated against Staphylococcus aureus. QR-NPO-NLCs could transport QR to an intranuclear location within HaCaT cells, indicating that QR-NPO-NLCs are promising candidates for controlled topical drug delivery.

The effectiveness of Fusarium solani pisi cutinase-mediated synthesis of short-chain alkyl esters in organic solvent (iso-octane) media was evaluated. A five-level, four-variable Central Composite Rotatable Design was employed. The parameters, chain length of alcohols and acids, alcohol and acid concentration, and the response (esterification yield and initial rate) were evaluated. The cutinase displayed an esterification yield above 95% for the C₄–C₆ acid and alcohol chain length with an optimal substrate concentration between 100 and 180 mM. Although an increase in acid and alcohol chain length resulted in a decrease of initial rate of reaction, the yield remained high (94% for the synthesis of butyl octanoate). PRACTICAL APPLICATIONS Short chain alkyl esters are very important flavoring compounds, appreciated for the fruity aroma they provide. Esterification is frequently encountered in the organic process industry in view of the diverse applications of esters in a variety of industries such as intermediates, pharmaceuticals, fine chemicals, fragrance and flavor chemicals, plasticizers, solvents and food. They are employed in fruit-flavored products (i.e., beverages, candies, jellies and jams), baked goods, wines and dairy products (i.e., cultured butter, sour cream, yogurt and cheese). Compounded flavor and fragrances are thus complex blends designed to impart either an attractive taste and aroma to processed foods and beverages, or a pleasing scent to consumer products such as perfumes, toiletries and household cleaners.

In recent years, gold nanoparticles (AuNPs) have aroused the interest of many researchers due to their unique physicochemical and optical properties. AuNPs are being explored in a variety of biomedical fields, either in diagnostics or therapy, particularly for localized thermal ablation of cancer cells after light irradiation. Besides the promising therapeutic potential of AuNPs, their safety constitutes a highly important issue for any medicine or medical device. For this reason, in the present work, the production and characterization of physicochemical properties and morphology of AuNPs coated with two different materials (hyaluronic and oleic acids (HAOA) and bovine serum albumin (BSA)) were firstly performed. Based on the above importantly referred issue, the in vitro safety of developed AuNPs was evaluated in healthy keratinocytes, human melanoma, breast, pancreatic and glioblastoma cancer cells, as well as in a three-dimensional human skin model. Ex vivo and in vivo biosafety assays using, respectively, human red blood cells and Artemia salina were also carried out. HAOA-AuNPs were selected for in vivo acute toxicity and biodistribution studies in healthy Balb/c mice. Histopathological analysis showed no significant signs of toxicity for the tested formulations. Overall, several techniques were developed in order to characterize the AuNPs and evaluate their safety. All these results support their use for biomedical applications.