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In this study, a polymeric drug delivery system based on chitosan and fish scale collagen was fabricated in the nanometer size by the emulsification method for loading lovastatin drug—a poorly water soluble drug for the treatment of reduction of cholesterol concentration in blood. An interesting point of this work is using collagen extracted from fresh water fish scales. The characteristics, properties, morphology and drug release control ability of the chitosan/collagen/lovastatin nanocomposites were evaluated by Infrared spectroscopy (IR), Field emission scanning electron microscopy (FESEM), Dynamic light scattering (DLS) and Ultraviolet–Visible spectroscopy (UV–Vis) methods. The obtained results showed that the chitosan/collagen/lovastatin nanocomposites are in spherical shape with the size of particles ranged from 72.1 to 444.0 nm. The chitosan/collagen system can improve the solubility and bioavailability of lovastatin in simulated gastric and intestine fluids. The drug release mechanism from chitosan/collagen/lovastatin nanocomposites was complied with the Korsmeyer-Peppas model. In addition, the in vivo test on mice of chitosan/collagen/lovastatin nanocomposites to investigate their toxicity was conducted and discussed.Graphic Abstract

This paper presents the characteristics of fly ash which was modified by 2-mercaptobenzothiazole (MBT) and sodium dodecyl sulfate (SDS) as the surfactants after treating with 1M NaOH solution. The change in morphology, specific surface area, crystal structure, and composition of the unmodified and modified fly ash was evaluated by FTIR, XRD, FESEM, BET, and EDX methods and techniques. The FTIR spectra of modified fly ash showed that there was no chemical reaction between the surfactants and fly ash. The XRD patterns and FESEM images indicated that modified fly ash had zeolite structure with a pore size of about 50 nm. Heavy metal ion adsorption behavior as well as adsorption isotherm models (Langmuir and Freundlich) of Cd2+ and Hg2+ ions of the unmodified and modified fly ash were also investigated and discussed. The amount of adsorbed ions of the modified fly ash was higher than that of the unmodified fly ash. The calculated results from the adsorption data according to the adsorption isotherm models of the above ions displayed that the Langmuir isotherm model was complied for the Cd2+ adsorption process while the Freundlich isotherm model was fitted for the Hg2+ adsorption process.

This study attempted to develop carrageenan/chitosan based microparticles loading α-mangostin which was extracted from Vietnamese mangosteen skin. The carrageenan/chitosan/α-mangostin microparticles were prepared by ionic gelation method by mixing chitosan, carrageenan with α-mangostin and subsequently cross-linking the mixtures with sodium tripolyphosphate crosslinking agent. The content of α-mangostin in microparticles was changed to evaluate the effect of α-mangostin content on physical, morphological properties, particles size and bioactivities of the carrageenan/chitosan/α-mangostin microparticles. The obtained results showed that carrageenan, chitosan was interacted together and with α-mangostin. The presence of polymers matrix improved the release ability of α-mangostin into ethanol/pH buffer solutions. The carrageenan/chitosan/α-mangostin microparticles have antibacterial (gram ( +) strains) and antioxidant activities. The results suggested that combination of chitosan and carrageenan in the microparticles can enhance the control release of α-mangostin into solutions as well as keep the bioactivities and reduce the vero cell toxicity of α-mangostin.

This article reports the interactions between lovastatin—a drug for treatment of reducing cholesterol and ginsenoside Rb1—a active substance extracted from Panax ginseng as model drugs loaded by alginate/chitosan blend. The polymer composite films based on chitosan (CS), alginate (AG), lovastatin (Lov) and ginsenoside Rb1 were prepared by solution method with the ratio of AG/CS fixed at 4/1, the content of Rb1 fixed at 5 wt% and content of Lov changed from 5 to 20 wt% in comparison with the weight of CS and AG. The morphology, structure and thermal behavior of alginate/chitosan blend loading both lovastatin and ginsenoside Rb1 were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry methods. Besides, the in-vitro drug release study of lovastatin and ginsenoside Rb1 from AG/CS blend was carried out in different pH buffer solutions for 32 h. The ultraviolet–visible spectra showed two adsorbed peaks corresponding to the optical adsorption of lovastatin and ginsenoside Rb1. The data of drug release content confirmed that lovastatin and ginsenoside Rb1 could affect to each other on drug release from the composite films. The drug release kinetics of lovastatin and ginsenoside Rb1 from the composite films in different pH buffer solutions were also determined to evaluate the interactions between lovastatin and ginsenoside Rb1 fully.

This paper presents the characteristics, morphology, and properties of alginate/chitosan/polyphenol nanoparticles, in which polyphenols were extracted from Camellia chrysantha leaves collected in Tam Dao district, Vinh Phuc province (Vietnam). The alginate/chitosan/polyphenol nanoparticles were prepared by ionic gelation method at different polyphenol content. The characteristics and morphology of these nanoparticles were investigated using infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM). Release kinetic of polyphenols from the alginate/chitosan/polyphenol nanoparticles was conducted in simulated human body fluids. The release kinetics of polyphenols from the above nanoparticles were also evaluated and discussed. The experimental results showed that the release process of polyphenols from the nanoparticles was dependent on three factors: time, pH of solution, and amount of polyphenols.

Chromium-based metal-organic framework MIL101(Cr)–CdSe quantum dot (QD) composites were synthesized by two different approaches: (a) loading the pre-synthesized CdSe QDs onto the surface of the MIL101(Cr) particles [denoted as CdSe/MIL101(Cr)] and (b) in situ synthesis of CdSe QDs into the pores of MIL101(Cr) (denoted as CdSe@Cr-MIL-101). The effect of synthesis technique on morphology, gas adsorption and photoluminescent properties of the as-prepared MOF-QD composites has been investigated. It was found that the porosity of composite materials strongly depends on the loading amount of CdSe QDs. Interestingly, the incorporation of CdSe QDs into/onto to MIL101(Cr) has enhanced optical absorption of the composites in the visible region (redshift) and therefore has potential applications in photocatalysis or solar cells.

This study assessed the methylene blue adsorption using natural and modified mussel shell powders in the aqueous solution. The mussel shell samples were processed in a NaClO solution then modified with sodium dodecyl sulfate and ethylenediaminetetraacetic acid. The characteristics of mussel shell samples before and after modification were demonstrated using infared spectroscopy, thermogravimetric analysis, scanning electron microscopy, nitrogen adsorption/desorption, energy dispersive X-ray, water contact angle, and dynamic light scattering methods. Some factors such as the pH of the medium, adsorption temperature, and adsorption time had a significant effect on the methylene blue adsorption of mussel shell samples. The adsorption isotherm models and kinetics of methylene blue adsorption by mussel shell samples were also studied. A quadratic regression equation was selected with experimental planning following the Box-Behnken model combined with Design Expert 11.1.0.1 software to optimize the methylene blue adsorption process by mussel shell samples. These results open a promising direction for using naturally derived materials to remove organic pollutants from contaminated water.

Yellow phosphorus is used widely in the world for production of phosphoric acid, various phosphates, flame retardant, detergent, water treatment, metal surface treatment, etc. After the production of yellow phosphorus, a large amount of phosphorus sludge is discharged to environment, causing environment pollution. This work focused on treatment of yellow phosphorus slag (YPS) and application of it as an absorbent for chromium (VI) ion and methylene blue. The YPS was first washed with water to remove phosphoferrite (FeP) and impurities and then being milled and transferred to a float sorting system to obtain YPS particles. The characteristics of YPS particles were determined by inductively coupled plasma-mass-spectrometry (ICP-MS), energy-dispersive X-ray spectroscopy (EDX), infrared spectroscopy (IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), zeta potential, and nitrogen adsorption methods. The YPS particles were retreated with NaOH, HNO3, and EDTA solutions to evaluate the influence of these agents on metal ion and organic compound adsorption ability by YPS. The adsorption parameters of chromium (VI) ion and methylene blue (MB) by treated YPS particles were recognized by the ultraviolet-visible (UV-Vis) spectrometer. The effects of temperature, pH solution, and initial concentration of absorbed substances on the adsorption ability were investigated. The adsorption isotherms and adsorption kinetics of chromium (VI) ion and MB by YPS particles were also determined. The obtained results confirmed that the green technology used to treat the YPS2 particles is suitable to obtain an effective absorbent. The adsorption efficiency of YPS2 particles for removal of chromium (VI) ions is smaller than that for removal of MB in aqueous solutions. The adsorption isotherm of MB adsorption process is complied with the Langmuir isotherm while the adsorption kinetic fits well with the pseudo-second-order reaction model. The thermodynamic parameters of MB adsorption processed on YPS2 were calculated and discussed.

In this paper, the chromium, Cr (VI), ion adsorption ability of oyster shell samples collected from two sea regions in Vietnam (Phu Yen province and Quang Ninh province) was investigated and compared. The oyster shell samples were calcined at different temperatures and denatured by using ethylenediaminetetraacetic acid (EDTA). The Cr (VI) ion adsorption ability of the prismatic (PP) and nacreous (NP) shell layers of oysters was also evaluated. The characteristics of oyster shell samples before and after treatment were determined by using analysis methods including XRD, IR, BET, UV-Vis, and FESEM. The Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models and fit statistic equations were used to study the adsorption isotherms of Cr (VI) ion adsorption by oyster shells. The Cr (VI) ions adsorption kinetic has been set up using four reaction models consisting of first-order, pseudo-first-order, second-order, and pseudo-second-order reaction models. Effects of experimental factors on the Cr (VI) ion adsorption process using oyster shells were also investigated and discussed in this work.