Xanthan-Based Materials as a Platform for Heparin Delivery.

Heparin (Hep), with its anticoagulant activity, antiangiogenic and apoptotic effects, and growth factor binding, plays an important role in various biological processes. Formulations as drug delivery systems protect its biological activity, and limit the potential side effects of faulty administration. The objective of this study was to develop novel xanthan-based materials as a delivery carrier for heparin. The materials exhibited remarkable elastic behavior and toughness without any crack development within the network, which also support their application for tissue engineering. It was found that all materials possessed the ability to control the release of heparin, according to the Korsmeyer-Peppas release model. All Hep-containing materials caused significant exchanges of the activated partial thromboplastin time (aPTT) and prothrombin time (PT) parameters, indicating that formulated natural/natural synthetic polymeric networks conserved heparin's biological activity and its ability to interrupt the blood coagulation cascade. The obtained results confirmed that developed materials could be carriers for the controlled release of heparin, with potential applications in topical administration.

Artificial Neural Network Models for Accurate Predictions of Fat-Free and Fat Masses, Using Easy-to-Measure Anthropometric Parameters.

Abdominal fat and fat-free masses report a close association with cardiometabolic risks, therefore this specific body compartment presents more interest than whole-body masses. This research aimed to develop accurate algorithms that predict body masses and specifically trunk fat and fat-free masses from easy to measure parameters in any setting. The study included 104 apparently healthy subjects, but with a higher-than-normal percent of adiposity or waist circumference. Multiple linear regression (MLR) and artificial neural network (ANN) models were built for predicting abdominal fat and fat-free masses in patients with relatively low cardiometabolic risks. The data were divided into training, validation and test sets, and this process was repeated 20 times per each model to reduce the bias of data division on model accuracy. The best performance models used a maximum number of five anthropometric inputs, with higher R2 values for ANN models than for MLR models (R2 = 0.96-0.98 vs. R2 = 0.80-0.94, p = 0.006). The root mean square error (RMSE) for all predicted parameters was significantly lower for ANN models than for MLR models, suggesting a higher accuracy for ANN models. From all body masses predicted, trunk fat mass and fat-free mass registered the best performance with ANN, allowing a possible error of 1.84 kg for predicting the correct trunk fat mass and 1.48 kg for predicting the correct trunk fat-free mass. The developed algorithms represent cost-effective prediction tools for the most relevant adipose and lean tissues involved in the physiopathology of cardiometabolic risks.

The Importance of HDL-Cholesterol and Fat-Free Percentage as Protective Markers in Risk Factor Hierarchy for Patients with Metabolic Syndrome.

This research focused on establishing a hierarchy concerning the influence of various biological markers and body composition parameters on preventing, diagnosing and managing Metabolic Syndrome (MetS). Our cross-sectional cohort study included 104 subjects without any atherosclerotic antecedent pathology, organized in two groups (with and without MetS). All participants underwent clinical and anthropometric measurements, DEXA investigation and blood tests for all MetS criteria, together with adiponectin, leptin, insulin, uric acid and CRP. Based on mathematical logic, we calculated a normalized sensitivity score to compare the predictive power of biomarkers and parameters associated with MetS, upon the prevalence of MetS. Patients with MetS report higher levels of uric acid (p = 0.02), CRP (p = 0.012) and lower levels of adiponectin (p = 0.025) than patients without MetS. The top three biological markers with the highest predictive power of the prevalence of the disease are HDL, insulin, and adiponectin:leptin ratio, and the top three body composition parameters are trunk fat-free percentage, waist-height ratio and trunk fat percentage. Their high sensitivity scores differentiate them from all the other markers analysed in the study. Our findings report relevant scores for estimating the importance of cardiometabolic risks in the prevalence of MetS. The high rank of protective markers, HDL and trunk fat-free percentage, suggest that positive effects have a stronger association with the prevalence of MetS, than negative ones do. Therefore, this risk stratification study provides important support for prevention and management programs regarding MetS.

Metabolic Phenotypes-The Game Changer in Quality of Life of Obese Patients?

BACKGROUND: The present study aimed to investigate the association of obesity phenotypes and quality of life (QoL) scales and their relationship with fat mass (FM) parameters. METHODS: This study categorized 104 subjects into 4 obesity phenotypes based on BMI and metabolic syndrome status: metabolically healthy obese (MHO), metabolically unhealthy obese (MUO), metabolically healthy non-obese (MHNO), and metabolically unhealthy non-obese (MUNO). Body composition was measured by dual-energy X-ray absorptiometry (DEXA) and metabolic profile was characterized by blood samples. All subjects completed the SF-36 item Short Form Health Survey Questionnaire. RESULTS: Comparing the four obesity phenotypes, significant results were reported for Bodily Pain between MHNO/MUNO (p = 0.034), for Vitality between MHO/MUO (p = 0.024), and for Mental Component Score between MHO/MUO (p = 0.026) and MUO/MUNO (p = 0.003). A more thorough inside-groups analysis yielded a positive and moderate to high correlation between FM parameters and QoL scales in MHO and MHNO, while a negative and weak to moderate correlation was observed in MUO and MUNO. CONCLUSION: This study reported an inverse U-shaped relationship between FM and QoL in obesity phenotypes, suggesting that metabolic status is a key factor involved in modulating QoL and therefore challenging the idea of obesity as a main driver of low QoL. We recommend the inclusion of FM percentage in the definition of obesity phenotypes in future research, to better evaluate QoL of obesity phenotypes.

[Surface properties and characteristics of PU-PTHF/MDI/HPC poly(ether)urethane for cardiovascular prosthesis]. / Caracteristicile si proprietatile de suprafata ale poli(eter)uretanului PU-PTHF/MDI/HPC cu potentiale aplicatii in protezarea cardiovasculara.

UNLABELLED: The polyurethanes are very used materials for medical devices. Their segmented block-copolymeric structures endows them a wide range of versatility in terms of tailoring their physical properties, and tissue compatibility. MATERIAL AND METHOD: A new polyether-urethane based material (PU-PTHF/MDI/HPC) was studied on bio-integration capacity in cardiovascular applications. In this respect, surface and bulk structure analysis, albumin and fibrinogen adsorption (in noncompetitive and competitive condition) and thrombogenicity have been evaluated. It was found that PU-PTHF/MDI/HPC surfaces had different roughness and bulk interconnected, well developed porous structure. As protein adsorption properties, preferential adsorption for albumin of material was observed. RESULTS: Thus, 0.280 +/- 0.04 mg/cm2 and 0.260+0.01 mg/ cm2 of albumin adsorb on PU-PTHF/MDI/HPC in noncompetitive and competitive conditions, while fibrinogen adsorption was 0.044 +/- 0.02 mg/cm2 and 0.040 +/- 0.01 mg/cm2. The clot amount test experiment have shown that clot weight of control blood was 24.8 +/- 2.03 mg, the clot weight formed by polyurethane was 28.4 +/- 2.93 mg and the clot weight formed by thrombogenic positive control (collagen membrane) was 42.5 +/- 3.50 mg. CONCLUSIONS: From our study we could conclude: 1--PU-PTHF/MDI/HPC polyurethane membranes have two-interface structure that could be advantageous for cavitary or tubular medical devices; 2--the protein adsorption results and clot formation test revealed a thromboresistent behavior of PU-PTHF/MDI/HPC, appropriate for cardiovascular applications.

Surface characterization of biopolyurethanes based on cellulose derivatives.

Surface tension parameters and surface morphology of biopolyurethanes based on cellulose derivatives thin films, before and after HF cold plasma treatment has been investigated. Calculations are based on the geometric mean approach of Owens and Wendt, Rabel and Kälble, on the Lifshitz-van der Waals acid/base approach of van Oss and co-workers and on the theoretical methods involving quantitative structure-property relationship. For all the investigated samples the polar component contributes significantly to the total surface tensions, as due to the large electron donor interactions. HF cold plasma treatment modifies the surface energy of biopolyurethanes by changing their surface polarity and hydrophilicity. The hydrophilic/hydrophobic balance was studied by means of the free energy of hydration between the biomaterial film and water. The protein adsorption tests of fibrinogen were effected to evaluate the applicability of these biopolyurethanes as biomedical thromboresistant devices.

[Preclinical assay on a magnetic carrier type ferrofluid]. / Studiu preclinic asupra unui purtator magnetic tip ferofluid.

UNLABELLED: The aim of the study was to determine the acute toxicity and the antimicrobial actions of an original magnetic carrier, type ferrofluid. The hydrophilic ferrofluid was prepared by covering the Fe3O4 nannoparticles with ammoniumoleate. The absolute amount of iron was of 40 mg/ml ferrofluid. METHODS: Acute toxicity was evaluated on five groups of Swiss male mice, after a single intraperitoneal administration of 1, 0.75, 0.5, 0.25 and 0.125 ml dose of pure ferrofluid/100 g body weight (b.w.), using step-level toxicity method. The study groups of mice were follow-up for 10 days. We did not use the same volume of solution for all the study groups because we were concerned about not to modify the behavior of the ferrofluid (but for each group we used the same volume of solution). The tasks of this part of the study were: 1) the record of the mice death in the first 10 days after intraperitoneal administration of ferrofluid; 2) the behavior of the animal subjects; 3) the morphopathologic examination of kidney, lung, heart, liver and peritoneum samples from the death mice and from the after ten days survivors which were sacrificed. We also investigated the possible antibacterial actions of the ferrofluid on E. coli spp., Klebsiella spp., Staphylococcus aureus Streptococcus group D., in the second part of the study, using standard lab kit. The validation of the results was performed using controls for E. colli and Staphylococcus aureus. RESULTS: The death of the mice was registered between 24 and finished after 96 hours. The maximum tolerated dose (MTD), was of 0.25 ml (10 mg iron/100 g b.w.) and the lethal dose hundred percent (LD100) was of 0.75 ml/(30 mg iron/100 b.w.). In our study we did not determined any kind of antibacterial action of the ferrofluid. CONCLUSIONS: 1) LD100, in our study, was of 30 mg iron/100 g b.w., and DMT of 10 mg iron/100 g b.w. 2) The death of the mice may be due to toxic aggression of ammonium ions released, in vivo, from the ammoniumoleate coverage of magnetite nannoparticles. 3) There were no in vitro antibacterial actions for this ferrofluid.