Experimental Studies on the Removal of Aluminium Ions from Synthetic Aqueous Solution by Hydroxyapatites

In this work we have presented the results obtained in the adsorption behavior of hydroxyapatite with different treatment towards aluminium ions from synthetic wastewaters. Experiments were performed in batch technique at different pH values, temperatures, sorbent dosage, contact time and initial aluminium concentration. The thermodynamic studies on the adsorption process of aluminium onto hydroxyapatite indicated that the process is spontaneous and endothermic. The Langmuir, Freundlich, Flory-Huggins, Dubinin-Radushkevich and Temkin equilibrium models were applied to the description of experimental data. The adsorption of aluminium follows the Langmuir adsorption isotherm. The kinetics of adsorption was evaluated using the pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models. The rate of aluminium adsorption was successfully described by a pseudo-second-order kinetic model. The obtained results indicated that hydroxyapatite treated with Pluronic P123 surfactant has a higher sorption capacity toward aluminium ions (117.65 mg g−1) than hydroxyapatite treated with Pluronic F127 surfactant (109.89 mg g−1) while untreated hydroxyapatite exhibited the lowest one (104.17 mg g−1).

Ciprofibrate-Loaded Nanoparticles Prepared by Nanoprecipitation: Synthesis, Characterization, and Drug Release

Ciprofibrate (CIP) is a highly lipophilic and poorly water-soluble drug, typically used for dyslipidemia treatment. Although it is already commercialized in capsules, no previous studies report its solid-state structure; thus, information about the correlation with its physicochemical properties lacking. In parallel, recent studies have led to the improvement of drug administration, including encapsulation in polymeric nanoparticles (NPs). Here, we present CIP’s crystal structure determined by PDRX data. We also propose an encapsulation method for CIP in micelles produced from Pluronic P123/F127 and PEO-b-PCL, aiming to improve its solubility, hydrophilicity, and delivery. We determined the NPs’ physicochemical properties by DLS, SLS, ELS, and SAXS and the loaded drug amount by UV-Vis spectroscopy. Micelles showed sizes around 10–20 nm for Pluronic and 35–45 nm for the PEO-b-PCL NPs with slightly negative surface charge and successful CIP loading, especially for the latter; a substantial reduction in ζ-potential may be evidenced. For Pluronic nanoparticles, we scanned different conditions for the CIP loading, and its encapsulation efficiency was reduced while the drug content increased in the nanoprecipitation protocol. We also performed in vitro release experiments; results demonstrate that probe release is driven by Fickian diffusion for the Pluronic NPs and a zero-order model for PEO-b-PCL NPs.

Phase Separation Effect in Gelation of 3DOM Bioactive Glass

The quaternary phase bioactive glasses (SiO2-CaO-Na2O-P2O5) were synthesized by the sol-gel process. Pluronic P123, using surfactant as structure-directing agents as well as phase separation inducers. The obtained bioactive glasses were characterized regarding morphology by using the scanning electron microscopy (SEM). Polymer colloidal crystals (CCTs) as the template component yielded either three-dimensionally ordered macroporous (3DOM) structure or hollow spheres shaped bioactive glass. The other type of morphology generation is related to the polymerization-induced phase separation (PIPS) in the gelation process. The heterogeneous precursor i.e. silica-rich regions caused the microspheres and solvent-rich areas produced micrometer-scale void space in bicontinuos structure. While the lower pH of starting precursor in 45S4P showed stronger precursor-template interactions than the 53S4P by generating the completely hollow spheres structure.

A Novel TEPA-Load or PEI-Load Beta/KIT-6 Composite and their Application to CO2 Adsorption

An amine-modified Beta/KIT-6 (BK) micro/mesoporous composite for CO2 capture was synthesized using nonionic tri-block copolymer pluronic (P123) as a template, tetraethyl orthosilicate (TEOS) as a silicon source and Beta zeolite as part of silicon aluminum source by a two-step hydrothermal crystallization method. BK was modified by Tetraethylenepentamine (TEPA) or polyethyleneimine (PEI) to obtain solid amine adsorbent. The structure, uniformity and physical properties of the sample were characterized by FTIR, nitrogen adsorption/desorption and elemental analysis methods and CO2 adsorption/desorption behavior of adsorbents and regeneration performance were investigated by thermal gravimetric analysis (TGA). Experimental results showed that with the increase of amine loading the CO2 adsorption capacity of samples increased first and then decreased at [Formula: see text]C, TEPA-loaded BK and PEI-loaded BK both presented the largest saturated CO2 adsorption capacity when the amine loading reached 60%, and the maximum values were 4.21[Formula: see text]mmol[Formula: see text]g[Formula: see text] and 2.72[Formula: see text]mmol[Formula: see text]g[Formula: see text], respectively. BK-TEPA-60 and BK-PEI-60 reached the maximum adsorption capacity at [Formula: see text]C and [Formula: see text]C. The adsorption kinetics analysis showed that the adsorption process of amine-modified BK was dominated by both physical and chemical adsorption. After five cycles of adsorption/desorption, BK-PEI-60 kept better stability with the equilibrium adsorption capacity of exhibited just 2.9% attrition, whereas a 9.2% decrease was obtained for BK-TEPA-60. Compared with other amine-modified solid materials, the materials we designed show good CO2 adsorption performance, indicating that they are promising efficient adsorbents for CO2 capture.

Novel Surface-Modified Bilosomes as Functional and Biocompatible Nanocarriers of Hybrid Compounds

In the present contribution, we demonstrate a new approach for functionalization of colloidal nanomaterial consisting of phosphatidylcholine/cholesterol-based vesicular systems modified by FDA-approved biocompatible components, i.e., sodium cholate hydrate acting as a biosurfactant and Pluronic P123—a symmetric triblock copolymer comprising poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) blocks Eight novel bilosome formulations were prepared using the thin-film hydration method followed by sonication and extrusion in combination with homogenization technique. The optimization studies involving the influence of the preparation technique on the nanocarrier size (dynamic light scattering), charge (electrophoretic light scattering), morphology (transmission electron microscopy) and kinetic stability (backscattering profiles) revealed the most promising candidate for the co-loading of model active compounds of various solubility; namely, hydrophilic methylene blue and hydrophobic curcumin. The studies of the hybrid cargo encapsulation efficiency (UV-Vis spectroscopy) exhibited significant potential of the formulated bilosomes in further biomedical and pharmaceutical applications, including drug delivery, anticancer treatment or diagnostics.