Hollow cathode plasma nitriding of medical grade Ti6Al4V: A comprehensive study.

Ti6Al4V used in biomedical applications still has several surface-related problems, such as poor bone compatibility and low wear resistance. In this work, the formation of a protective layer of titanium nitride obtained by plasma treatment in hollow cathode was studied, and the best experimental conditions were verified by a statistical factorial design of experiments. The samples were characterized in terms of their physical and chemical properties, correlating the effects of time (min) and temperature (°C). An achieved ideal condition was further analysed in terms of in vitro cytotoxicity, micro-abrasion, and electrochemical properties. The carried-out assessment has shown that nitrided condition has an improvement in wettability, microhardness, along with TixNy formation and roughness increment, when compared to pristine condition.

Polyurethane/poly(d,l-lactic acid) scaffolds based on supercritical fluid technology for biomedical applications: Studies with L929 cells.

Biomaterials can be applied in tissue engineering as scaffolds that resemble the extracellular matrix functioning as a temporary structure for cell proliferation and reconstruction of new organs and tissues. To evaluate the potential use of scaffolds as a biomaterial, this work proposes the development and characterization of polyurethane (PU), poly(D,L-lactic acid) (PDLLA) and polyurethane/poly(d,l-lactic acid) (PU/PDLLA) scaffolds produced by gas foaming technique. The neat polymers and the blends were characterized, in film form, by gel permeation chromatography (GPC), thermogravimetry (TG), differential scanning calorimetry (DSC) and field emission gun scanning electron microscopy (FEG-SEM). After supercritical fluid technology, in scaffolds form, the samples were characterized by FEG-SEM, pore size, density, cytotoxicity and cell adhesion. For film characterization the PU/PDLLA sample presented intermediate characteristics compared to the neat polymers, exhibiting the behavior of both polymers in the sample without phase separation in the FEG-SEM micrograph and bimodal molar weight distribution by GPC. The scaffolds showed interconnectivity and pore size of 141 µm ±â€¯108 µm for PUsc and 52 µm ±â€¯32 µm for PDLLAsc. The PU/PDLLAsc exhibited a bimodal structure in which the PU in the mixture revealed pores of 75 µm ±â€¯57 µm, while for PDLLA, the pore size was 19 µm ±â€¯12 µm. In vitro tests confirmed the adhesion of L929 cells to PUsc, PDLLAsc and PU/PDLLAsc, showing no cytotoxic effect. Finally, it can be concluded that it is possible to produce PU, PDLLA and PU/PDLLA scaffolds by supercritical fluid, which may be applied as biomaterials.

Investigation of plasma treatment on UHMWPE surfaces: Impact on physicochemical properties, sterilization and fibroblastic adhesion.

Ultra-high molecular weight polyethylene (UHMWPE) is a prevailing bearing material applied in joint arthroplasty. Despite not being a novel biomaterial, its debris as consequence of long application and surface properties usually still lead to short lifespan. Many of the drawbacks are associated with sterilization methods that degrade the surface properties of UHMWPE. This work aims at improving the sterilizing treatment and also increasing material wettability, without losing bulk properties, which are essential for an orthopedic bearing. Cold plasma in hollow cathode setting was used for the material surface functionalization. Samples were characterized through contact angle (WCA), x-ray diffraction (XRD), optical microscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and profilometry. Optimal points based on immediate surface wettability, shelf time and sterilization efficacy were chosen for biocompatibility evaluation. When comparing cell viability through MTT among treated samples (OP1, OP2 and UV), a slight reduction in OP2 viability could be seen after 7 days incubation, which is also observed in Giemsa staining and SEM images. In late incubation, OP1 loses its hydrophilic character and displays higher cell adhesion than its counterparts UV and OP2. At the end, OP2 showed less cells growing over the biomaterial after 7 days exposition compared to OP1 and UV. OP1 presented a more hydrophobic surface and improved cell adhesion, differently from OP2 and UV, which maintained their wettability conditions in late incubation. Cell analysis results indicate that surface wetting influences cell morphology and consequent cell adhesion, in which more hydrophobic surfaces are shown to favor fibroblast adhesion properties.

Chemical Characterization and Cytotoxic Activity of Blueberry Extracts (cv. Misty) Cultivated in Brazil.

Vaccinium corymbosum (L.) varieties cultivation is relatively recent in Brazil, but its production has been intensified given its good adaptability to the Southern Brazil climate. Blueberries are a rich source of phenolic compounds and contain significant levels of anthocyanins, flavonols, chlorogenic acids, and procyanidins, which lead to different biological activities. Chemical identification of skin and whole hydroalcoholic blueberry extracts (ExtSB and ExtWB) revealed the presence of anthocyanins concentrated in the skin and others chemicals compounds as quercetin glycosides, proanthocyanins dimers, citric, and chlorogenic acid in the pulp. Selectivity for tumor cell lines (Hep-2, HeLa, HT-29) using ExtSB and ExtWB extracts was observed through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after 24 h of treatment when compared to nontumor cells (MRC-5). Morphological changes and late stages of apoptotic and necrosis process were seen in HT-29 cell line after ExtWB treatment, compared to nontumor cell line MRC-5. These results are in agreement with other studies that indicate the activity of compounds such as anthocyanins and other molecules found in Southern Highbush blueberry variety, attributed to promote beneficial effects on health that may respond as cytotoxic natural agent and contribute to cancer treatment.

Chemical characterization, antioxidant and cytotoxic activities of Brazilian red propolis.

Propolis is known for a long time for its health benefits and biological activities. Here, the red variety from the northeast of Brazil was chemically analyzed and extracts were investigated regarding their antioxidant and antitumor activity. Hydroalcoholic extracts, obtained from the red propolis, revealed polyphenol content, 2,2-diphenyl-1-picrylhydrazyl scavenging potential and enzymatic activities for catalase-like and superoxide dismutase-like. Cytotoxic activity was evaluated for human laryngeal epidermoid carcinoma cell (Hep-2), human cervical adenocarcinoma (HeLa) and human normal epithelial embryonic kidney (Hek-293). Survival analysis for non-tumor cell line showed greater IC50 compared to tumor cell lines, suggesting an increased sensitivity that may correlate with the higher proliferative index of the tumor vs. normal cells. Our results indicate that the Brazilian red propolis is capable of inhibiting cancer cell growth and constitutes an excellent source of antioxidant and antitumor natural agent.

Enxerto autólogo de células-tronco derivadas do tecido adiposo: uma nova visão de sua aplicação no tratamento de queimados e na cirurgia plástica reparadora / Adipose tissue-derived stem cell autologous grafts: a new approach to application in the treatment of burn victims and reconstructive plastic surgery

No Brasil, 1 milhão de acidentes com queimaduras acontecem por ano e as infecções são responsáveis por 75% dos óbitos nestes pacientes, além de deixar lesões que ocasionam deformidades nas áreas atingidas. Sendo assim, o objetivo deste trabalho é fornecer uma visão atual sobre células-tronco mesenquimais (MSCs), com ênfase nas células-tronco derivadas do tecido adiposo (ADSCs), associadas a gel de plasma, gel de fibrina e membranas (scaffold). O uso de géis e membranas tendem a auxiliar o crescimento celular visando sua possível aplicação na Cirurgia Plástica Reparadora para o tratamento pacientes queimados ou que necessitam de enxerto de pele. O presente trabalho abordou de forma exploratória e narrativa o tema células-tronco mesenquimais, células-tronco mesenquimais derivadas do tecido adiposo, gel de fibrina, gel de plasma e scaffold. O tipo de pesquisa empregada foi conduzido com coleta de informações utilizando-se a Biblioteca Virtual em Saúde (BVS) e PubMed. O número absoluto de artigos publicados relacionados ao tratamento de queimaduras é considerável. Até o momento, a quantidade de pesquisas relacionadas à terapia com células-tronco derivadas do tecido adiposo, gel de fibrina, gel de plasma e scaffold para o tratamento de queimaduras apresenta-se escassa. O autoenxerto de ADSCs associado a biocurativos torna-se uma perspectiva promissora na Cirurgia Plástica Reparadora para o tratamento e recuperação de pacientes que sofreram queimaduras ou outros acidentes que necessitam de enxerto de pele. Estes recursos podem reduzir a dor e prover a dessecação da lesão, promovendo neovascularização e a reepitelização da ferida.

In Brazil, 1 million burn accidents occur annually, and subsequent wound infections account for 75% cases of deaths among these patients, in addition to inducing deformities in the affected areas. Therefore, the aim of this study was to discuss the current status of mesenchymal stem cells, with an emphasis on adipose-derived stem cells (ADSCs), in combination with plasma gel, glue fibrin, and membranes (scaffold). The use of gels and membranes supports cell growth, and aims at potential application in reconstructive plastic surgery for the treatment of burn patients or individuals requiring skin grafts. This study explores and discusses the role of mesenchymal stem cells, adipose-derived mesenchymal stem cells, glue fibrin, plasma gel, and the scaffold. This research collected information from the Virtual Health Library (VHL) and PubMed. A considerable number of articles have been published on burn treatment. However, there is little research on burn treatment with ADSCs, glue fibrin, plasma gel, and scaffold. An ADSC autograft combined with a biological dressing is promising in reconstructive plastic surgery for the treatment and recovery of burn patients or individuals with other injuries that require skin grafts. These features can reduce pain and aid in drying of the lesion, thus promoting neovascularization and wound reepithelialization.

Avaliação in vitro do potencial biológico da Salvia officinalis L. em células tumorais / In vitro evaluation of the biological potential of Salvia officinalis L. in tumor cells

Objetivos: Determinar a viabilidade celular frente ao efeito biológico do extrato hidroalcoólico de Salvia officinalis L. em culturas de células tumorais de laringe (Hep-2) e células de hepatoma humano (HepG2).Métodos: Células tumorais Hep-2 e HepG2 foram cultivadas em meio DMEM (Dulbecco's Modified Eagle Médium)suplementado com 10% soro fetal bovino inativado e 1% de antibiótico (Penicilina/Estreptomicina) em estufa a 37°Ce atmosfera umidificada com 5% de CO2. Na segunda etapa foram semeadas (5×104 células/mL) em placas de 96 poçosdurante o período de 24 horas até obtenção de 60-70% de confluência e realizou-se o tratamento das células com extratohidroalcoólico de Salvia officinalis L., controle negativo de etanol 80% (v/v) e controles positivos de peróxido de hidrogênio(H2O2), tert-butil hidroperóxido (t-BOOH), doxorrubicina e cisplatina. A viabilidade celular foi determinada pela reduçãodo MTT (brometo de 3-(4,5 dimetiltiazol-2-il)-2,5-difeniltetrazolio). Os resultados foram analisados pelo teste de Tukeyno programa SPSS v.19.Resultados: O extrato hidroalcoólico de Salvia officinalis L. mostrou atividade citotóxica para células tumorais Hep-2 IC500,38±0,02 mg/mL e para HepG2 IC50 0,54±0,03 mg/mL em comparação ao controle negativo, ficando acima do IC50 obtidopara seus controles positivos. A cisplatina apresentou IC50 abaixo do extrato de sálvia, porém para a obtenção do seu IC50aumentou-se o tempo de exposição em seis horas.Conclusões: Sugere-se que o extrato de Salvia officinalis L. tem atividade biológica em células tumorais, podendo serobjetivo de mais estudos com a finalidade de comprovar sua eficácia como possível agente para o tratamento do câncer.

Aims: To determine cell viability compared to the biological effect of Salvia officinalis L. extract on cultured tumor cells of the larynx (Hep-2) and in human hepatoma cells (HepG2). Methods: Tumor cells Hep-2 and HepG2 were grown in DMEM (Dulbecco’s Modified Eagle Medium) supplemented with 10% inactivated fetal bovine serum and 1% antibiotics (Penicillin/Streptomycin), incubated at 37°C and 5% CO2. In the second step they were plated (5×104 cells/mL) in 96 well plates during 24 hours to obtain 60-70% confluency, and treated with the hydroalcoholic extract of Salvia officinalis L., negative control with 80% ethanol (v/v) and positive control of hydrogen peroxide (H2O2), tert-butyl hydroperoxide (t-BOOH), doxorubicin and cisplatin. Cell viability was determined by MTT reduction (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Results were analyzed by Tukey test using the SPSS v.19. Results: The hydroalcoholic extract of Salvia officinalis L. showed cytotoxic activity to tumor cells Hep-2 IC50 0,38±0.02 mg/mL for HepG2 IC50 0,54±0.03 mg/mL compared to negative control, staying above the IC50 obtained for their positive controls. Cisplatin showed IC50 below the extract of sage, but to obtain the IC50 exposure time was increased in six hours. Conclusions: The results of this study suggest that the extract of Salvia officinalis L. has biological activity against tumor cell; further studies are needed to confirm its efficacy and its potential role in cancer treatment.