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The presence of F− ions in water is either a helpful or harmful outcome, contingent upon the concentration level of the pollutant. In this work, hydroxyapatite/chitosan (HAp/CS) nanocomposites were prepared incorporating varying weight percentages of chitosan with HAp, using co-precipitation followed by lyophilization without employing any cross-linking agents for adsorption of F− ions. Increase in the concentration of chitosan with HAp matrix significantly enhanced the colloidal stability, F− ions adsorption capacity and reduced the particle size (length 38% and width 86%) compared to HAp. The maximum F− adsorption capacity of HAp/CS1, HAp/CS2, and HAp/CS4 nanocomposites are 56 mg/g, 80 mg/g and 100 mg/g at pH 7, which was considerably higher (10 times) than HAp when compared to other existing reports. The adsorption isotherm and kinetics of HAp and HAp/CS nanocomposite adsorbent confirm the monolayer and strong chemisorption. After adsorption of F− ions, the surface morphology of adsorbent changed from rod to sphere along with an increase in particle size, as confirmed by HR-TEM. Moreover, FTIR and XPS analysis revealed the surface interaction between adsorbent and F− ions through ion exchange and electrostatic interaction, which lead to formation of fluorapatite. HAp/CS4 showed 2.5 times higher sustainable regeneration efficiency (90% in 30 mins) up to 7th cycle than HAp. Furthermore, the solution pH (5–7) of treated water was maintained at neutral after fluoride adsorption, making the water potable. Hence, these results demonstrate that chitosan plays a major role in removal of F− ion and this composite is ideal for F− adsorption application.

Biocompatible polymer modified magnetic-luminescent nanocomposites with efficient heat generation for cancer hyperthermia applications.

The effect of swift heavy silicon ion irradiation on hydroxyapatite prepared by hydrothermal technique was analyzed. The physical and biological properties were studied using G1XRD, Micro-Raman, photoluminescence, AFM, SEM, EDX, in vitro bioactivity, antimicrobial activity and drug release. When compared with pristine the crystallinity increases with an increase in fluence. Slight reduction in crystallinity was noted for irradiated samples at higher fluence (1×1013 and 1×1014 ions/cm2) than lower fluence (1×1012 ions/cm2). After irradiation the υ4 O-P-O asymmetric bending mode peak at 583 cm−1 disappeared. The PL intensity increases with an increase in fluence and it had become narrow and showed red shift. This suggests the material could find application as phosphors. The enhancement in band gap was attained for irradiated samples than Hpris (5.38–5.5 eV). AFM studies revealed the enhancement of roughness, particle size and pores on irradiation. SEM exposed the creation of pores along with an increase in porosity (2 µm to 30 µm). Formation of platy crystals was noted for 1×1013 ions/cm2 sample. In vitro bioactivity results with the formation of spherical (2 µm) apatite deposition along with the presence of interconnected pores (2–10 µm) which could enhance osteointegration and osteoconduction. In addition, Ca/P ratio was found to increase after soaking in SBF. Initial burst release followed by sustained release was obtained upto 45 h. Therefore it could assist in the treatment of bone and joint infection. Hence, SHI had improved the material to be used in biomedical field as an implant due to its enhanced properties such as crystallinity, pore size, surface roughness, PL intensity, antimicrobial activity, drug release and bioactivity.

Contamination of arsenic in the form of arsenite (As3+) and arsenate (As5+) in potable water causes serious illness in the human body even at a very low concentration (10 µg / L). As3+ is comparatively 60 times more toxic than As5+ species. Hence, this work is focused on the preparation of adsorbents for efficient removal of As3+ with higher adsorption affinity at trace level (≤50 µg/L). Here, iron-doped hydroxyapatite (Fe-HAp) synthesized by hydrothermal technique is employed as an efficient adsorbent. A very less quantity of Fe2+ ion (0.5 wt %) is incorporated in the tetrahedral and octahedral sites of the HAp lattice along the c-axis which lead to drastic reduction in particle size (400%) and enhancing the specific surface area (105%), colloidal stability, and adsorption affinity. The maximum adsorption capacity of As3+ is 139±2 µg/g and 183±2 µg/g for HAp and Fe-HAp, respectively. The adsorption rate of Fe-HAp is very rapid which is 538% higher compared to HAp and also the As3+ adsorption affinity or sensitivity (0.71 µg/L) significantly improved 83-99% when compared to the adsorbents reported in the previous literature so far. The monolayer adsorption of As3+ is purely strong chemisorption as confirmed by the Langmuir and Dubinin–Radushkevich (DKR) isotherm. The structure and morphology of HAp and Fe-HAp remain unchanged after the adsorption of As3+ ions and also no secondary toxic products were observed. Hence, the above results reveal Fe-HAp as an efficient and low-cost adsorbent for removal of highly toxic As3+ ions at the trace level.

Multifunctional nanosized particles are very beneficial in the field of biomedicine. Bioactive and highly biocompatible calcium phosphate (CaP) nanoparticles (∼50 nm) exhibiting both superparamagnetic and fluorescence properties were synthesized by incorporating dual ions (Fe

Hypoxia is considered a key factor in cellular differentiation and proliferation, particularly during embryonic development; the process of early neurogenesis also occurs under hypoxic conditions. Apart from these developmental processes, hypoxia preconditioning or mild hypoxic sensitization develops resistance against ischemic stroke in deteriorating tissues. We therefore hypothesized that neurons resulting from hypoxia-regulated neuronal differentiation could be the best choice for treating brain ischemia, which contributes to neurodegeneration. In this study, infrapatellar fat pad (IFP), an adipose tissue present beneath the knee joint, was used as the stem cell source. IFP-derived stem cells (IFPSCs) are totally adherent and are mesenchymal stem cells. The transdifferentiation protocol involved hypoxia preconditioning, the use of hypoxic-conditioned medium, and maintenance in maturation medium with α-lipoic acid. The differentiated cells were characterized using microscopy, reverse transcription PCR, real time PCR, and immunocytochemistry. To evaluate the epigenetic reprogramming of IFPSCs to become neuron-like cells, methylation microarrays were performed. Hypoxia preconditioning stabilized and allowed for the translocation of hypoxia inducible factor 1α into the nucleus and induced achaete-scute homologue 1 and doublecortin expression. Following induction, the resultant cells expressed neuronal markers neuron-specific enolase, neurofilament-light chain, growth associated protein 43, synaptosome associated protein 25, and β-III tubulin. The differentiated neural-lineage cells had functional gene expression pertaining to neurotransmitters, their release, and their receptors. The molecular signaling mechanisms regulated developmental neurogenesis. Furthermore, the in vitro physiological condition regulated neurotransmitter respecification or switching during IFPSC differentiation to neurons. Thus, differentiated neurons were fabricated against the ischemic region to treat neurodegenerative diseases.