Microbial surfactants: fundamentals and applicability in the formulation of nano-sized drug delivery vectors

Microbial surfactants, so-called biosurfactants, comprise a wide variety of structurally distinct amphipathic molecules produced by several microorganisms. Besides exhibiting surface activity at the interfaces, these molecules present powerful characteristics including high biodegradability, low toxicity and special biological activities (e.g. antimicrobial, antiviral, anticancer, among others), that make them an alternative to their chemical counterparts. Several medical-related applications have been suggested for these molecules, including some reports on their potential use in the formulation of nano-sized drug delivery vectors. However, despite their promises, due to the generalized lack of knowledge on microbial surfactants phase behavior and stability under diverse physicochemical conditions, these applications remain largely unexplored, thus representing an exciting field of research. These nano-sized vectors are a powerful approach towards the current medical challenges regarding the development of efficient and targeted treatments for several diseases. In this review, a special emphasis will be given to nanoparticles and microemulsions. Nanoparticles are very auspicious as their size, shape and stability can be manipulated by changing the environmental conditions. On the other hand, the easiness of formulation, as well as the broad possibilities of administration justifies the recent popularity of the microemulsions. Notwithstanding, both vector types still require further developments to overcome some critical limitations related with toxicity and costs, among others. Such developments may include the search for other system components, as the microbial surfactants, that can display improved features.The author acknowledges the financial support from the Strategic Project PEst-OE/EQB/LA0023/2013 and project ref. RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462) funded by Fundacao para a Ciencia e a Tecnologia

La chirurgie du sourire : intérêt des ostéotomies maxillaires totales (Lefort I) et segmentaires antérieures

La découverte trop importante des gencives lors du sourire définit le sourire gingival. Il existe une inadéquation entre les parties molles et les bases osseuses. Cet article propose, à partir d’une série de cas cliniques, une approche thérapeutique adaptée aux différentes anomalies dento-maxillaires rencontrées lors du sourire gingival

Development and preliminary validation of the Sjögren’s Tool for Assessing Response (STAR): a consensual composite score for assessing treatment effect in primary Sjögren’s syndrome

Objectives: To develop a composite responder index in primary Sjögren’s syndrome (pSS): the Sjögren’s Tool for Assessing Response (STAR). Methods: To develop STAR, the NECESSITY consortium used data-driven methods, based on 9 randomized controlled trials (RCTs), and consensus techniques, involving 78 experts and 20 patients. Based on reanalysis of rituximab trials and literature, the Delphi panel identified a core set of domains with their respective outcome measures. STAR options combining these domains were proposed to the panel to select and improve them. For each STAR option, sensitivity to change was estimated by the C-index in 9 RCTs. Delphi rounds were run for selecting STAR. For the options remaining before the final vote, meta-analyses of the RCTs were performed. Results: The Delphi panel identified 5 domains (systemic activity, patient symptoms, lachrymal function, salivary gland function and biological parameters). A total of 227 STAR options, combining these domains, were selected to be tested for sensitivity to change in the 9 RCTs. After 2 Delphi rounds, meta-analyses of the 20 remaining options were performed. Then, the candidate STAR was selected by a final vote. Conclusion: The candidate STAR is a composite responder index, including in a single tool all main disease features, and dedicated for use as a primary endpoint in pSS RCTs. Its rigorous and consensual development process ensures its face and content validity. The candidate STAR showed a good sensitivity to change. The candidate STAR and its derived options will be prospectively validated in the dedicated RCT of the NECESSITY consortium

Lung hypoplasia in newborn rabbits with a diaphragmatic hernia affects pulmonary ventilation but not perfusion

BackgroundA congenital diaphragmatic hernia (DH) can result in severe lung hypoplasia that increases the risk of morbidity and mortality after birth; however, little is known about the cardiorespiratory transition at birth.MethodsUsing phase-contrast X-ray imaging and angiography, we examined the cardiorespiratory transition at birth in rabbit kittens with DHs. Surgery was performed on pregnant New Zealand white rabbits (n=18) at 25 days' gestation to induce a left-sided DH. Kittens were delivered at 30 days' gestation, intubated, and ventilated to achieve a tidal volume (V t) of 8 ml/kg in control and 4 ml/kg in DH kittens while they were imaged.ResultsFunctional residual capacity (FRC) recruitment and V t in the hypoplastic left lung were markedly reduced, resulting in a disproportionate distribution of FRC into the right lung. Following lung aeration, relative pulmonary blood flow (PBF) increased equally in both lungs, and the increase in pulmonary venous return was similar in both control and DH kittens.ConclusionThese findings indicate that nonuniform lung hypoplasia caused by DH alters the distribution of ventilation away from hypoplastic and into normally grown lung regions. During transition, the increase in PBF and pulmonary venous return, which is vital for maintaining cardiac output, is not affected by lung hypoplasia.SCOPUS: ar.jinfo:eu-repo/semantics/publishe