Mesoporous Silicon‐PLGA Composite Microspheres for the Double Controlled Release of Biomolecules for Orthopedic Tissue Engineering

In this study, poly(dl ‐lactide‐co‐glycolide)/porous silicon (PLGA/pSi) composite microspheres, synthesized by a solid‐in‐oil‐in‐water (S/O/W) emulsion method, are developed for the long‐term controlled delivery of biomolecules for orthopedic tissue engineering applications. Confocal and fluorescent microscopy, together with material analysis, show that each composite microsphere contained multiple pSi particles embedded within the PLGA matrix. The release profiles of fluorescein isothiocyanate (FITC)‐labeled bovine serum albumin (FITC‐BSA), loaded inside the pSi within the PLGA matrix, indicate that both PLGA and pSi contribute to the control of the release rate of the payload. Protein stability studies show that PLGA/pSi composite can protect BSA from degradation during the long term release. We find that during the degradation of the composite material, the presence of the pSi particles neutralizes the acidic pH due to the PLGA degradation by‐products, thus minimizing the risk of inducing inflammatory responses in the exposed cells while stimulating the mineralization in osteogenic growth media. Confocal studies show that the cellular uptake of the composite microspheres is avoided, while the fluorescent payload is detectable intracellularly after 7 days of co‐incubation. In conclusion, the PLGA/pSi composite microspheres offer an additional level of controlled release and could be ideal candidates as drug delivery vehicles for orthopedic tissue engineering applications.     

Antiproliferative activity of peptides prepared from enzymatic hydrolysates of tuna dark muscle on human breast cancer cell line MCF-7

To produce and identify antiproliferative peptides, two commercial enzymes, papain (PA) and Protease XXIII (PR) were used to hydrolyse tuna dark muscle byproduct, and the protein hydrolysates were purified, before being evaluated for antiproliferative activities against human breast cancer cell line MCF-7. The results showed that the peptide fractions with the molecular weight ranging from 390 to 1400 Da possessed the greatest antiproliferative activity. The amino acid sequences of the two antiproliferative peptides isolated from PA and PR hydrolysates were Leu-Pro-His-Val-Leu-Thr-Pro-Glu-Ala-Gly-Ala-Thr (1206 Da) and Pro-Thr-Ala-Glu-Gly-Gly-Val-Tyr-Met-Val-Thr (1124 Da), whilst they show the dose-dependent inhibition effect of the MCF-7 cells with IC₅₀ values of 8.1 and 8.8 μM, respectively. We thus conclude that antiproliferative hydrolysates from tuna dark muscle byproduct may be useful ingredients in food and nutraceutical applications.     

Effects of Microbial Transglutaminase on the Wheat Proteins of Bread and Croissant Dough

ABSTRACT: Transglutaminase is a crosslinking enzyme that is finding increasing use in foods, yet the molecular changes responsible for its effects are not fully understood. Proteins were extracted from bread and croissant doughs that had been treated with transglutaminase and compared to those from control doughs by size exclusion high performance liquid chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. Transglutaminase increased the amount of protein extracted in the gliadin fraction in both bread and croissant doughs. In croissant doughs, a corresponding decrease in the protein extracted in the albumin to globulin fraction was seen. In each case, crosslinking of the high molecular weight glutenins was observed. The possible role of each of these changes on the functional properties of baked products is discussed.     

Biohydrometallurgical/UV production of ferrous sulphate heptahydrate crystals from pyrite present in coal tailings

The objective of this work was to develop a biohydrometallurgical/UV radiation route to produce ferrous sulphate heptahydrate (melanterite) from the pyrite present in coal tailings. The experimental work was carried out with a pyrite concentrate obtained from gravimetric processing of coal tailing. At laboratory scale it was performed the oxidation of pyrite in an aqueous medium in packed bed leaching columns in an oxidising environment with the presence of acidophilic bacteria (Acidithiobacillus ferrooxidans). The recirculation of the liquor allowed obtaining an iron-rich extract. The conversion of Fe³⁺ to Fe²⁺ was performed using ultraviolet irradiation (UV). Finally, the solution was evaporated allowing the formation of iron sulphate crystals. The results demonstrated that it is possible to produce high purity ferrous sulphate heptahydrate crystals using coal tailings as raw material.     

Perception of mistuned harmonics in complex sounds by the bullfrog (Rana catesbeiana).

The ability of 73 male bullfrogs (Rana catesbeiana) to detect single mistuned harmonics in an otherwise periodic signal was studied. Bullfrogs in their natural environment were presented with playbacks of synthetic signals, resembling their species advertisement calls, that differed in the frequency of 1 harmonic component (out of 22). There were significant differences in the number and latency of the males' evoked vocal responses to these stimuli, suggesting that males were sensitive to the differences between the sounds. Differences in envelope shape (rate and depth of amplitude modulation) produced by the harmonic mistunings may underlie the differences in response. Frogs, like birds and humans, can discriminate sounds on the basis of harmonic structure, indicating that this is a general perceptual trait shared among vertebrates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developing community capacity to treat post-deployment mental health problems: A public health initiative.

Meeting the mental health needs of Veterans returning from recent deployment requires the coordinated effort of partnerships across Department of Defense (DoD), Department of Veterans Affairs (VA), and state and local communities. Although the proportion of Veterans of Iraq and Afghanistan who have accessed VA health care has grown, the majority of these new combat Veterans have yet to present for VA care. The stigma associated with reporting a deployment-related mental health problem may be one factor in this, but access to treatment may also be an important concern among the one third of American Veterans who live in rural or highly rural areas. As these Veterans are more likely to present to a primary care, faith-based or mental health provider in their own community, partnerships between community providers, DoD, and VA are of critical importance in ensuring appropriate care, regardless of treatment setting. In an effort to improve services and access to services, especially to rural Veterans, an educational public health initiative was created to educate community providers about military culture, deployment-related mental health issues, VA resources, and evidence-based treatments. We describe the development, dissemination and evaluation of this initiative, as well as lessons learned for future similar endeavors. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Diagnostic sleep testing in the evaluation of snoring and sleep apnea

The dilemma frequently encountered by the dentist wishing to offer an appliance for treatment of snoring or sleep apnea is whether there is a need for extensive testing of patients who present with a complaint of snoring. This article describes diagnostic sleep testing in the evaluation of patients with snoring and sleep apnea.     

Experimental studies on substituted copper phthalocyanine Langmuir-Blodgett films

Using the Langmuir-Blodgett (LB) technique, novel copper bis(3-hydroxypropyloxy-hexaisopentyloxy)phthalocyanine molecules were deposited on quartz substrates. It is argued on the basis of pressure-area isotherms that films are deposited as monolayers. Optical absorption spectroscopy suggests that the deposited films were uniform. A.c. measurements were performed on LB films in a planar configuration at different temperatures. The power-law dependence of the conductivity on frequency is explained in terms of electronic conduction through hopping over a coulombic barrier 0.66 eV high. The Debye relaxation time is estimated to be of the order 811 µs at room temperature.