Cristina Ott

Ivy leaves extract based – lipid nanocarriers and their bioefficacy on antioxidant and antitumor activities

In this study, two issues commonly associated with phytochemical based nanotechnology were addressed: (1) the use of active compounds from medicinal herbs as functional ingredients entrapped into lipid-based nanocarriers; (2) the safety and efficacy of phytochemical-based nanocarriers with promising antioxidant and antitumor benefits. In this context, nanostructured lipid carriers (NLC) based on raspberry seed oil (Rso), pomegranate seed oil (Pso) and rice bran oil (Rbo) were synthesized and proven to be highly effective for the entrapment of hydrophilic ivy leaves extract (Ile). The size, morphology, zeta potential, entrapment efficiency and crystallinity of the Ile-loaded NLC were characterized. The effectiveness of Ile loaded-NLC has been proved by identifying a high capacity to scavenge free oxygen radicals (i.e. between 94 and 98%). 200 μg mL−1 Ile-NLC based on Rbo showed no significant effects on cellular viability in the fibroblast L929 cell line, while the tumor B16 cell line was markedly affected. MTS, RTCA assays and apoptosis examination revealed that these nanocarriers induce cytotoxicity and apoptosis in the murine melanoma B16 cell line. This study reports the first evidence of the association of hydrophilic and lipophilic phytochemicals in the same lipid nanocarriers, which appears to be a promising antioxidant and antitumor approach deserving further investigation.

Integrative approach in prevention and therapy of basal cellular carcinoma by association of three actives loaded into lipid nanocarriers

Basal cell carcinoma (BCC) is one of the commonest malignancies occurred on sun-exposed skin, mainly by UV-B radiation, of lighter-skinned individuals. The aim of the present study was to develop advanced drug delivery formulations used in BCC therapy that overcomes chemotherapy-induced side-effects of skin photosensitivity by an integrative approach of nanoencapsulation in conjunction with combination therapy that uses chemotherapeutic, chemoprotective and sunscreen agents. The combination of anticancer drug together with sunscreen agent is very useful in therapy, especially for individuals who are more exposed to the sun without using a sunscreen. Nanostructured lipid carriers (NLCs) employed as drug delivery systems were co-loaded with 5-fluorouracil (5-FU), a hydrophilic chemotherapeutic drug, and ethylhexyl salicylate (EHS), a lipophilic UV-B sunscreen agent. The NLCs were developed using bioactive squalene (50.8% w/w) from amaranth seed oil as chemoprotective agent. By varying the concentrations of 5-FU and EHS, the co-loaded NLCs presented particle sizes of about 100nm, acceptable physical stability with values smaller than -25mV and appropriate entrapment efficiency that reaches values over 65% for both types of drugs. The UV-B blocking ability of EHS loaded into NLCs were influenced by the concentration of 5-FU. The amaranth oil offered a capacity of 70% in scavenging the free radicals. In vitro drug release showed that NLCs presented sustained release of 5-FU that followed the Ficks law of diffusion.

CONDENSATION REACTIONS OF PLANAR CHIRAL TRICARBONYL- CHROMIUM-COMPLEXED BENZYLIC ALCOHOLS AND ACETATES WITH REACTIVE ARENES

The condensation reaction of planar chiral 2- and 2,5-substituted tricarbonyl-chromium complexed benzylic alcohols and acetates with reactive arenes (durene, anisole, 1,3-dimethoxybenzene, diphenyl ether) is reported. The reactions were performed in both racemic and enantiomeric versions, optically pure R-(+)- and S-(-)-[2-methoxybenzyl alcohol]-tricarbonyl-chromium being prepared by LiAlH4 reduction of diastereomeric, t.l.c. separated, (-)-menthyl esters of [2-methoxybenzoic acis]-tricarbonyl-chromium. The condensation of the difunctional complex [1,4-diacetoxymethylene-2,5-dimethoxybenzene]-tricarbonyl-chromium with an excess of anisole proved the same reactivity at both reactive benzylic sites thus serving as a model for possible polycondensation process. Corresponding optically pure difunctional starting complexes were obtained by t.l.c. separation of diasteromeric diesters with R-(-)-lactic or S-(-)-mandelic acids.