Development of Liposomes Loaded with Chloroaluminum Phthalocyanine for Application of Photodynamic Therapy in Breast Cancer.

Chloraluminium phthalocyanine (ClAlPc) has potential therapeutic effect for the treatment of cancer; however, the molecule is lipophilic and may present self-aggregation which limits its clinical success. Thus, nanocarriers like liposomes can improve ClAlPc solubility, reduce off-site toxicity and increase circulation time. For this purpose, developing suitable liposomes requires the evaluation of different lipid compositions. Herein, we aimed to develop liposomes containing soy phosphatidylcholine (SPC), 1,2-distearoyl-sn-glycero- 3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPEPEG2000), cholesterol and oleic acid loaded with ClAlPc using the surface response methodology and the Box-Behnken design. Liposomes with particle size from 110.93 to 374.97 nm and PdI from 0.265 to 0.468 were obtained. The optimized formulation resulted in 69.09 % of ClAlPc encapsulated, with particle size and polydispersity index, respectively, at 153.20 nm and 0.309, providing stability and aggregation control. Atomic force microscopy revealed vesicles in a spherical or almost spherical shape, while the analyzes by Differential Scanning Calorimetry (DSC), Powder X-ray Diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR) suggested that the drug was adequately incorporated into the lipid bilayer of liposomes, in its amorphous state or molecularly dispersed. In vitro studies conducted in breast cancer cells (4T1) showed that liposome improved phototoxicity compared to the ClAlPc solution. ClAlPc-loaded liposomes also enhanced the production of ROS 3-fold compared to the ClAlPc solution. Finally, confocal microscopy and flow cytometry demonstrated the ability of the liposomes to enter cells and deliver the fluorescent ClAlPc photosensitizer with dose and time-dependent effects. Thus, this work showed that Box-Behnken factorial design was an effective strategy for optimizing formulation development. The obtained ClAlPc liposomes can be applied for photodynamic therapy in breast cancer cells.

Anti-inflammatory withajardins from the leaves of Athenaea velutina.

Withajardins, uncommon modified withanolide-type steroids, have been isolated exclusively from plants of the Solanaceae family so far. Two undescribed withajardins and the known tuboanosigenin were isolated from the hexane/EtOAc 1:1 extract from Athenaea velutina leaves. Their structures were established by an extensive analysis of 1D and 2D-NMR and HRMS data. The absolute configuration was determined by X-ray diffraction (withajardin L and tuboanosigenin) and circular dichroism (CD) analyses (withajardin M). The anti-inflammatory activity of compounds was evaluated through the inhibition of the lipopolysaccharide (LPS)-induced nitric oxide (NO), TNF-α, and IL-6 release in RAW264.7 cells. The cell viability effects to RAW 264.7 cells showed IC50 values of 74.4-354.4 µM. The compounds attenuated LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 in RAW264.7 cells.

Vibrational and conformational analysis of structural phase transition in Estradiol 17ß valerate with temperature.

Estradiol 17ß valerate (E2V) is a hormonal medicine widely used in hormone replacement therapy. E2V undergoes a reversible isosymmetric structural phase transition at low temperature (Ì´ 250 K) which results from the reorientation of the valerate chain. The reversible isosymmetric structural phase transition follows Ehrenfest's classification when described as first-order and Buerger's classification when classified as order-disorder. The conformational difference also induces changes in molecular torsional angles and on the hydrogen bond pattern. In combination with density functional theory (DFT) calculations, vibrational spectroscopy has been used to correlate the valerate chain modes with the modifications of the dihedral angles on phase transition. We are expecting improvement in our understanding of the phase transition mechanism driven by the temperature. The Conformational analysis reveals the feasible structures corresponding to changes in the dihedral angles associated with the valerate chain. The infrared spectra of calculated conformers are in good agreement with the experimental spectra of E2V structure recorded at room temperature revealing that the changes in valerate chain modes at 1115 cm-1, 1200 cm-1and 1415 cm-1 fingerprint the molecular conformation. An investigation made to determine the ligand-protein interaction of E2V through docking against estrogen receptor (ER) reveals the inhibitive and agonist nature of E2V.

Tropane alkaloids from the stem bark of Erythroxylum bezerrae.

Six previously undescribed tropane alkaloids, designated as erythrobezerrines A-F, were isolated from the EtOH extract from the stem bark of Erythroxylum bezerrae Plowman. Their structures were elucidated based on the interpretation of the NMR and MS data and in some instances, confirmed by X-ray diffraction analysis. The cytotoxicity of the isolated compounds was evaluated against the cancer cell lines L929, PC-3, HCT-116, SNB-19 and NCI-H460, but only erythrobezerrine C showed moderate activity with IC50 values of 3.38 and 5.43 µM for HCT-116 and NCI-H460, respectively.

Study of molecular structure, vibrational, electronic and NMR spectra of oncocalyxone A using DFT and quantum chemical calculations.

Oncocalyxone A (C17H18O5) is the major secondary metabolite isolated from ethanol extract from the heartwood of Auxemma oncocalyx Taub popularly known as "pau branco". Oncocalyxone A (Onco A) has many pharmaceutical uses such as: antitumor, analgesic, antioxidant and causative of inhibition of platelet activation. We have performed the optimized geometry, total energy, conformational study, molecular electrostatic potential mapping, frontier orbital energy gap and vibrational frequencies of Onco A employing ab initio Hartree-Fock (HF) and density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set. Stability of the molecule arising from hyperconjugative interactions and/or charge delocalization has been analyzed using natural bond orbital (NBO) analysis. UV-vis spectrum of the compound was recorded in DMSO and MeOH solvent. The TD-DFT calculations have been performed to explore the influence of electronic absorption spectra in the gas phase, as well as in solution environment using IEF-PCM and 6-31G basis set. The (13)C NMR chemical shifts have been calculated with the B3LYP/6-311++G(d,p) basis set and compared with the experimental values. These methods have been used as tools for structural characterization of Onco A.

An optimized animal model for partial and total skin thickness burns studies / Um modelo animal aperfeiçoado para estudo de queimaduras superficiais e profundas da pele

PURPOSE: Development of an improved animal model for studying skin burns in rats. METHODS: Twenty-four male Wistar rats were randomly assigned to four groups (n=6): G1-Control, G2- T100°C, G3-T150°C and G4-T200°C. Two 10 x 10 mm squares were outlined with a sterile surgical marker on each side and along the vertebral column using a prepared template positioned between the anterior and posterior limbs. G2-G4 rats were subjected to 100°C, 150°C and 200ºC thermal burns, respectively. G1 rats served as controls. Burns were inflicted by applying a copper plate connected to an electronic temperature controlling device to the dorsal skin of anesthetized rats. Four burns were produced on each animal (total area: 4 cm²/animal) leaving about 1 cm of undamaged skin between burn areas. Analgesia was administered during 24 h after burn injury by adding 30 mg codeine phosphate hemihydrate to 500 ml tap water. RESULTS: The application of 100°C and 150ºC resulted in partial thickness skin burns with central reepithelialization of the burned area only at 100°C. In G4 group the whole thickness of the skin was injured without central reepithelialization. However, there was marginal reepithelialization in all groups. CONCLUSION: The model studied is inexpensive and easily reproducible, enabling the achievement of controlled burns with partial or total impairment of the skin in experimental animals.

OBJETIVO: Desenvolvimento de um modelo animal aperfeiçoado para estudo de queimaduras cutâneas em ratos. MÉTODOS: Vinte e quatro ratos Wistar, machos, foram distribuídos aleatoriamente em quatro grupos (n=6): G1-Controle, G2-T100°C, G3-T150°C e G4-T200°C. Dois quadrados medindo 10x10 mm foram delineados com um marcador cirúrgico estéril em cada lado e ao longo da coluna vertebral e posicionados entre os membros anteriores e posteriores, utilizando um molde previamente preparado. Os ratos dos grupos G2-G4 foram submetidos a queimaduras térmicas de 100°C, 150°C e 200°C, respectivamente. O grupo G1 foi utilizado como controle. As queimaduras foram infligidas pela aplicação de uma placa de cobre, ligada a um dispositivo de controle eletrônico de temperatura, na pele dorsal de ratos anestesiados. Quatro queimaduras foram produzidas em cada animal (área total: 4 cm2/animal), deixando cerca de 1 cm de pele intacta entre as áreas queimadas. Analgesia foi obtida durante 24 horas após a queimadura por adição de 30mg de fosfato hemi-hidratado de codeína a 500 ml de água potável. RESULTADOS: A aplicação 100°C e 150°C resultou na produção de queimaduras profundas comprometendo parte da espessura da pele, com reepitelização central da área queimada, somente a 100°C. No grupo G4 houve lesão de toda a espessura da pele sem reepitelização central. Entretanto, observou-se reepitelização marginal em todos os grupos estudados. CONCLUSÃO: O modelo estudado é de baixo custo e facilmente reproduzível, propiciando a obtenção controlada de queimaduras com comprometimento parcial ou total da pele, em animais experimentais.