Magnetic Mesoporous Silica for Targeted Drug Delivery of Chloroquine: Synthesis, Characterization, and In Vitro Evaluation.

Malaria is a dangerous tropical disease, with high morbidity in developing countries. The responsible parasite has developed resistance to the existing drugs; therefore, new drug delivery systems are being studied to increase efficacy by targeting hemozoin, a parasite paramagnetic metabolite. Herein, magnetic mesoporous silica (magMCM) was synthesized using iron oxide particles dispersed in the silica structure for magnetically driven behavior. The X-ray diffractogram (XRD) and Mössbauer spectra show patterns corresponding to magnetite and maghemite. Furthermore, Mössbauer spectroscopy revealed superparamagnetic behavior, attributed to single magnetic domains in particles smaller than 10 nm. Even in the presence of iron oxide particles, the hexagonal structure of MCM is clearly identified in XRD (low-angle region) and the channels are visible in TEM images. The drug chloroquine (CQ) was encapsulated by incipient wetness impregnation (magMCM-CQ). The N2 adsorption-desorption isotherms show that CQ molecules were encapsulated in the pores, without completely filling the mesopores. BET surface area values were 630 m2 g-1 (magMCM) and 467 m2 g-1 (magMCM-CQ). Encapsulated CQ exhibited rapid delivery (99% in 3 h) in buffer medium and improved solubility compared to the non-encapsulated drug, attributed to CQ encapsulation in amorphous form. The biocompatibility assessment of magMCM, magMCM-CQ, and CQ against MRC5 non-tumoral lung fibroblasts using the MTT assay after 24 h revealed no toxicity associated with magMCM. On the other hand, the non-encapsulated CQ and magMCM-CQ exhibited comparable dose-response activity, indicating a similar cytotoxic effect.

The Relationship between Unintentional Weight Loss, Grading System and Overall Survival in Gastric Cancer Patients.

Cancer patients are highly vulnerable to weight loss and malnutrition, before chemotherapy, thus reducing overall survival (OS). The objective was assessing weight loss and OS prognostication in gastric cancer patients at baseline of chemotherapy treatment. Observational retrospective study with patients who were treating in cancer public clinic in Brazil, was evaluated weight loss and cachexia. It was evaluated by sex, BMI, grade system classification (GSC) and stage the OS by Kaplan-Meier method and Cox proportional hazards model. Ninety-two patients, 73.9% were male. At baseline chemotherapy patients have presented 15.3% of body weight loss, 28.3% were malnourished, 86.8% classified witch cachexia, 80.3% were grade 3-4 in GSC and 86.9% at cancer stage 3-4. OS was lower for male (15.9 mo.), malnourished (12.0 mo.), GCS-4 (16.3 mo.) and Stage 4 (13.3 mo.) patients. GSC grade four and BMI classification to underweight comparing obesity are associated with reduced OS, together to male sex and cancer stage 4, have gotten together shown that seems to confer a survival disadvantage to other patients in these parameters too. Cox regression analysis have not shown statistical significance for sex, Initial BMI Class, GSC, cancer stage. Gastric cancer patients at chemotherapy treatment outset present high weight loss, cachexia prevalence and OS reduction.

Designing a Support for Lipase Immobilization Based On Magnetic, Hydrophobic, and Mesoporous Silica.

A mesoporous, magnetic, and hydrophobic material was designed step by step to act as a support for lipase immobilization. Its pore size (8.0 nm) is compatible with the size of lipase from Thermomyces lanuginosus (TLL), and its hydrophobic surface (contact angle of a water drop = 125°) was planned to interact with lipase on its interfacially activated form (open conformation). The presence of magnetite particles provides magnetic retrieval of the material and enables recyclability of the biocatalysts. Regarding immobilization parameters, the hydrophobic support was tested in comparison to the unmodified hydrophilic support in phosphate buffer solution (50 mmol L-1, pH 7.5) at 25 °C. Hydrophobicity was found to be critical for the amount of immobilized TLL (immobilization yield of 97% versus 36% for the hydrophilic support), whereas the hydrophilic support favors the native conformational state and substrate access to the enzyme's catalytic site (specific activity of 5.7 versus 4.7 U g-1 for the hydrophobic support, even when it has higher TLL content). Therefore, the hydrophobic support immobilizes higher amounts of TLL and the hydrophilic support keeps the enzyme hyperactivated. Last, due to the stronger interactions of TLL with hydrophobic surfaces, the hydrophobic support offers better preservation of enzyme activity in repeated cycles (76% of activity retained after three cycles versus 50% for the hydrophilic support).

Agreement analysis of oscillometric devices in the measure of resting heart rate in breast cancer survivors.

OBJECTIVE: The aim of this study was to verify the reproducibility of an oscillometric device in the measurement of resting heart rate (RHR) in breast cancer survivors. METHODS: This study included 85 breast cancer survivors with a mean age of 58.87±10.03 years. For the RHR evaluation, the equipment used was the Omron HEM 742, electronic and digital arm device, for measurement of blood pressure and heart rate (HR), with automatic cuff inflation and deflation. At the same time as the oscillometric measurement, HR was measured by the HR monitor Polar RS800 CX, which has been validated previously for HR uptake. The HR value obtained by the cardiofrequency meter was registered at the same time that the Omron device measured blood pressure and HR values. RESULTS: It was observed that the RHR values were very close in both devices and that the correlation values and intraclass correlation coefficient were high. These results were replicated when the female breast cancer survivors were stratified by age group. The agreement values presented by the Bland-Altman analysis showed good values; both for the entire sample and stratified by age, few cases were outside beyond 95% confidence interval range. CONCLUSION: The present study showed that the oscillometric device used presented good values of reproducibility in the detection of RHR values in breast cancer survivors compared with a cardiac monitor.

Body Position May Influence Oronasal CPAP Effectiveness to Treat OSA.

CPAP applied by a nasal mask is the gold standard treatment of obstructive sleep apnea. Oronasal masks are an alternative interface that can be used, especially in subjects with predominant oral breathing. However, oronasal masks have higher costs, are associated with larger leaks and higher residual apnea-hypopnea index, and in some cases may be ineffective.