Development of nanofibrous scaffolds containing polylactic acid modified with turmeric and hydroxyapatite/vivianite nanoparticles for wound dressing applications.

Damaging the outer layer of the body (the skin) has been a common issue for decades. Fabrication of nanofibrous membranes via the electrospinning technique for the sake of making the wound healing process more facile has caught a lot of interest. For this purpose, a polymeric scaffold of polylactic acid (PLA) was doped with nanoparticles with different concentrations of turmeric/hydroxyapatite/vivianite/graphene oxide. The obtained membrane was tested by XRD, SEM, FTIR, and XPS. The surface topography of the scaffold has experienced changes upon adding different concentrations of the nanoparticles. The contact angle was measured by water droplets. It accentuated change in CA starting from 43.9o for pure condition of PLA to 67.7o for PLA/turmeric/vivianite. The thermogravimetric analysis (TGA) test stated that the PLA scaffold features are thermally stable in relatively high-temperature conditions initiating from room temperature to about 300 °C, meeting the maximum loss in mass of about 5 %. The cell viability was carried out in prepared vitro for the sample which contains PLA/turmeric/vivianite/GO, it was elucidated that the IC50 was around 3060 µg/ml.

Empirical and theoretical insights into the structural effects of selenite doping in hydroxyapatite and the ensuing inhibition of osteoclasts.

The use of ions as therapeutic agents has the potential to minimize the use of small-molecule drugs and biologics for the same purpose, thus providing a potentially more economic and less adverse means of treating, ameliorating or preventing a number of diseases. Hydroxyapatite (HAp) is a solid compound capable of accommodating foreign ions with a broad range of sizes and charges and its properties can dramatically change with the incorporation of these ionic additives. While most ionic substitutes in HAp have been monatomic cations, their lesser atomic weight, higher diffusivity, chaotropy and a lesser residence time on surfaces theoretically makes them prone to exert a lesser influence on the material/cell interaction than the more kosmotropic oxyanions. Selenite ion as an anionic substitution in HAp was explored in this study for its ability to affect the short-range and the long-range crystalline symmetry and solubility as well as for its ability to affect the osteoclast activity. We combined microstructural, crystallographic and spectroscopic analyses with quantum mechanical calculations to understand the structural effects of doping HAp with selenite. Integration of selenite ions into the crystal structure of HAp elongated the crystals along the c-axis, but isotropically lowered the crystallinity. It also increased the roughness of the material in direct proportion with the content of the selenite dopant, thus having a potentially positive effect on cell adhesion and integration with the host tissue. Selenite in total acted as a crystal structure breaker, but was also able to bring about symmetry at the local and global scales within specific concentration windows, indicating a variety of often mutually antagonistic crystallographic effects that it can induce in a concentration-dependent manner. Experimental determination of the lattice strain coupled with ab initio calculations on three different forms of carbonated HAp (A-type, B-type, AB-type) demonstrated that selenite ions initially substitute carbonates in the crystal structure of carbonated HAp, before substituting phosphates at higher concentrations. The most energetically favored selenite-doped HAp is of AB-type, followed by the B-type and only then by the A-type. This order of stability was entailed by the variation in the geometry and orientation of both the selenite ion and its neighboring phosphates and/or carbonates. The incorporation of selenite in different types of carbonated HAp also caused variations of different thermodynamic parameters, including entropy, enthalpy, heat capacity, and the Gibbs free energy. Solubility of HAp accommodating 1.2 wt% of selenite was 2.5 times higher than that of undoped HAp and the ensuing release of the selenite ion was directly responsible for inhibiting RAW264.7 osteoclasts. Dose-response curves demonstrated that the inhibition of osteoclasts was directly proportional to the concentration of selenite-doped HAp and to the selenite content in it. Meanwhile, selenite-doped HAp had a significantly less adverse effect on osteoblastic K7M2 and MC3T3-E1 cells than on RAW264.7 osteoclasts. The therapeutically promising osteoblast vs. osteoclast selectivity of inhibition was absent when the cells were challenged with undoped HAp, indicating that it is caused by selenite ions in HAp rather than by HAp alone. It is concluded that like three oxygens building the selenite pyramid, the coupling of (1) experimental materials science, (2) quantum mechanical modeling and (3) biological assaying is a triad from which a deeper understanding of ion-doped HAp and other biomaterials can emanate.

Brain aging in normal Egyptians: cognition, education, personality, genetic and immunological study.

Studying the cognitive and immunological changes that occur in old age as well as genetic function have been considered an important subject to differentiate between normal brain aging and early dementia especially Alzheimer's disease. The aim of this study is to stress on age-related neuropsychological and electrophysiological (P(300)) changes in normal Egyptian subjects, to throw light on the value of genetic (Apo-E(4) genotype) and immunological markers [interleukin-6 (IL-6) and intercellular adhesion molecules (ICAM-1) in the serum] as tools used in early detection of cognitive decline in cerebral aging. Ninety-four normal Egyptian subjects (below and above 60 years) were submitted to the following: (1) neuropsychological tests for testing memory, perception, psychomotor performance and attention, (2) Eysenck Personality Questionnaire (EPQ) for personality traits, (3) event-related potential study (P(300), latency and amplitude), (4) genetic test for detection of Apolipoprotein E genotype and (5) immunological studies including detection of the level of IL-6 and ICAM-1 in serum. There was a significant impairment of memory, psychomotor performance and perception in elderly subjects particularly males and subjects with low level of education. Regarding personality, significantly high scores were obtained in neuroticism scale of EPQ in elderly subjects. Apo-E(3)/E(3) was the most common genotype encountered in Egyptian subjects (49.1%). It was found that subjects with Apo-E(4) genotype did significantly worse in scores of intentional memory test (sensory memory) when compared with other genotypes. Statistically significant impairment in attention and sensory memory was found in subjects with high IL-6 level. This could not be detected in subjects with high ICAM-1 level. In conclusion, advancing age and lower levels of education are considered risk factors for cognitive decline in normal brain aging. Neuropsychological tests remain as the highly sensitive tools for detection of early cognitive impairment. Neurotic traits are more encountered in old age. Apo-E(4) genotype is associated with significant sensory (intentional) memory impairment. High IL-6 level in the serum is accompanied by significant impairment in attention and sensory (intentional) memory.