High Bioactive Potential Research Articles

Physicochemical properties and biomimetic behaviour of α-TCP-chitosan based materials

In this paper we present a complex study on the preparation and characterization of the cement-type implant material composed of α-tricalcium phosphate and chitosan. α-TCP has already been used as an initial component of bone cement formulations. In most cases, however, it was synthesized using a solid state reaction. In our studies, highly reactive α-TCP powder was obtained by a wet chemical method. Chitosan is well known as a safe and biocompatible polymer. In our studies it was used to improve the characteristic of the cements. Chitosan was introduced into the bone cements in the form of acetic acid solution and acted as a binder for agglomerates of calcium phosphate grains but at the same time the impeded creation of interconnections inside the agglomerates. The concentration of acetic acid influenced the pore size distribution. In vitro investigations proved the high bioactive potential of the examined materials.

Bioactivity of cement type bone substitutes

Abstract In vitro chemical stability and bioactivity of three different cement type bone substitutes were determined by incubating cement samples in the simulated body fluid (SBF) for 7 and 28 days. Morphology of sample surfaces has been studied using scanning electron microscopy (SEM) combined with an energy dispersive X-ray spectroscopy (EDS) and by atomic force microscopy (AFM). The diffuse reflectance Fourier-transform infrared spectroscopy (DRIFTS) was applied as a supplementary method. The development of bone-like apatite layers on the surface depended on their initial phase composition. Obtained cements showed good surgical handiness, high bioactive potential and were chemically stable. They seem to be promising materials for bone substitution.

Conhecimento da comunidade universitária em relação aos alimentos funcionais

Functional foods have physiologically active components capable of promoting health, and nutritional benefits. The grape and its derivatives, due to the compounds with high bioactive potential, especially resveratrol, were chosen as a research subject in the assessment of consumer knowledge regarding functional foods. The study population was the community of three universities in the city of Maringá, Paraná State. A questionnaire was developed and applied to a total of 485 individuals. The food most accepted and consumed was grape juice (51% acceptance), followed by red wine (49% acceptance). The soy drink grape-flavored, food with the lowest popularity has never been tried by 13% of the population interviewed, and 40% never consume this food. Of the interviewees, 48% seemed to be unaware or not sure of the health claims proposed in the questionnaire. This ignorance refers to the relationship of wine and phenolic compounds with positive effects on the blood pressure, osteoporosis, diuresis and depression. Although the interest and curiosity about the functional food, young interviewed still do not know enough about the benefits of functional foods on human health.

Evaluation of a setting reaction pathway in the novel composite TiHA–CSD bone cement by FT-Raman and FT-IR spectroscopy

The aim of this study was to determine a setting reaction pathway in a novel, surgically handy implant material, based on calcium sulfate hemihydrate (CSH) and titanium doped hydroxyapatite (TiHA). The previous studies confirmed superior biological properties of TiHA in comparison to the undoped hydroxyapatite (HA) what makes it highly attractive for future medical applications. In this study the three types of titanium modified HA powders: untreated, calcined at 800°C, sintered at 1250°C and CSH were used to produce bone cements. The Fourier Transform-InfraRed (FT-IR) spectroscopy and Raman spectroscopy were applied to evaluate processes taking place during the setting of the studied materials. Our results undoubtedly confirmed that the reaction pathways and the phase compositions differed significantly for set cements and were dependent on the initial heat treatment of TiHA powder. Final materials were multiphase composites consisting of calcium sulfate dihydrate, bassanite, tricalcium phosphate, hydroxyapatite and calcium titanate (perovskite). The FT-IR and Scanning Electron Microscopy (SEM) measurements performed after the incubation of the cement samples in the simulated body fluid (SBF), indicate on high bioactive potential of the obtained bone cements.

Influence of solvent on the antioxidant and antimicrobial properties of walnut (Juglans regia L.) green husk extracts

Walnut green husk is an agro-forest waste generated in the walnut (Juglans regia L.) harvest that could be valued as a source of natural compounds with antioxidant and antimicrobial properties. At this respect, the effect of the solvent (water, methanol, ethanol and 50% aqueous solutions of methanol and ethanol) on the extraction yields and extracts bioactive properties was analysed. Total phenols content of the extracts was determined by the Folin–Ciocalteau method. Extract antioxidant activity was evaluated using the reducing power assay and by the ability of the extracts to scavenge the DPPH radical. The scavenging effect of the aqueous extracts on the nitric oxide radical was also evaluated. The highest extraction yield was achieved with water (44.11%) and high bioactive potential was shown by the samples extracted with water/ethanol (1:1) (84.46mg GAE/g extract; EC50=0.95mg/mL for reducing power and EC50=0.33mg/mL for DPPH assay). All the antioxidant properties analysed showed a concentration-dependent activity. The antimicrobial activity of the aqueous extracts was assessed and showed ability to inhibit the growth of Gram positive bacteria. The results obtained demonstrated the potential of the walnut green husk as an economical source of antioxidant and antimicrobial agents.