Mini review of microplastic pollutions and its impact on the environment and human health.

In recent years, the environmental pollution of microplastics (MPs) has increasingly drawn our attention. MPs are small fragments of plastics that are commonly dispersed in the environment. The accumulation of environmental MPs is due to population growth and urbanization, while natural disasters such as hurricanes, flooding and human activity may influence their distribution. The leaching of chemicals from MPs raises a significant safety problem and environmental approaches aimed at reducing the use and recycling of plastics, with the replacement by bioplastics and wastewater treatment developments are called for. This summary also helps in demonstrating the connection between terrestrial and freshwater MPs and wastewater treatment plants as the major contributors to environmental MPs by discharges of sludge and effluent. More research on the classification, detection, characterization and toxicity of MPs are essential to enable greater options and solutions. Control initiatives need to intensify the comprehensive study of MP waste control and management information programmes in the fields of institutional engagement, technological research and development, legislation and regulation. A comprehensive quantitative analysis approach for MPs should be created in the future, and more reliable traceability analysis methods should be built to examine further its environmental activity and existence, where this should be done to improve scientific research on MP pollution in terrestrial, freshwater and marine environments and hence, develop more scientific and rational control policies.

Enhancing the Decolorization of Methylene Blue Using a Low-Cost Super-Absorbent Aided by Response Surface Methodology.

The presence of organic dyes from industrial wastewater can cause pollution and exacerbate environmental problems; therefore, in the present work, activated carbon was synthesized from locally available oil palm trunk (OPT) biomass as a low-cost adsorbent to remove synthetic dye from aqueous media. The physical properties of the synthesized oil palm trunk activated carbon (OPTAC) were analyzed by SEM, FTIR-ATR, and XRD. The concurrent effects of the process variables (adsorbent dosage (g), methylene blue (MB) concentration (mg/L), and contact time (h)) on the MB removal percentage from aqueous solution were studied using a three-factor three-level Box-Behnken design (BBD) of response surface methodology (RSM), followed by the optimization of MB adsorption using OPTAC as the adsorbent. Based on the results of the analysis of variance (ANOVA) for the three parameters considered, adsorbent dosage (X1) is the most crucial parameter, with an F-value of 1857.43, followed by MB concentration (X2) and contact time (X3) with the F-values of 95.60 and 29.48, respectively. Furthermore, the highest MB removal efficiency of 97.9% was achieved at the optimum X1, X2, and X3 of 1.5 g, 200 mg/L, and 2 h, respectively.

Formulation and In-Vitro Characterisation of Cross-Linked Amphiphilic Guar Gum Nanocarriers for Percutaneous Delivery of Arbutin.

Nano-colloidal systems formulated from amphiphilically-modified polysaccharides (degree of modification 16.6%) are focus of prominent study due to their potential to augment active penetration across the skin. Here we report the synthesis of amphiphilically-modified guar gum (GBE-GG) prepared by grafting with glycidol butyl ether (GBE), which were subsequently formed into nanocarriers and loaded with α-arbutin (22.3% loading). The monodispersed and close-to-spherical nanocarriers (size range 239-297 nm) formed via cross-linking were adequately stable mainly at low temperature (4 °C) under physiological pH condition. α-arbutin was released from GBE-GG NPs in a more sustained manner and the release profiles can be accurately represented by the 1st order kinetic model. In-vitro interactions on immortalised human keratinocytes (HaCaT) cells revealed an increase in biological membrane permeability as well as the absence of cellular toxicity at application pertinent concentrations. No substantial haemolytic activity appeared and flow cytometry analysis revealed effective cellular uptake, suggesting their potential as promising nanocarriers for percutaneous delivery that warrants further comprehensive research.

Formation of Antihyperlipidemic Nano-Ezetimibe from Volatile Microemulsion Template for Enhanced Dissolution Profile.

Nanostructures play an important role in targeting sparingly water-soluble drugs to specific sites. Because of the structural flexibility and stability, the use of template microemulsions (µEs) can produce functional nanopharmaceuticals of different sizes, shapes, and chemical properties. In this article, we report a new volatile oil-in-water (o/w) µE formulation comprising ethyl acetate/ethanol/brij-35/water to obtain the highly water-dispersible nanoparticles of an antihyperlipidemic agent, ezetimibe (EZM-NPs), to enhance its dissolution profile. A pseudoternary phase diagram was delineated in a specified brij-35/ethanol ratio (1:1) to describe the transparent, optically isotropic domain of the as-formulated µE. The water-dilutable µE formulation, comprising an optimum composition of ethyl acetate (18.0%), ethanol (25.0%), brij-35 (25.0%), and water (32.0%), showed a good dissolvability of EZM around 4.8 wt % at pH 5.2. Electron micrographs showed a fine monomodal collection of EZM-loaded µE droplets (∼45 nm) that did not coalesce even after lyophilization, forming small spherical EZM-NPs (∼60 nm). However, the maturity of nanodrug droplets observed through dynamic light scattering suggests the affinity of EZM to the nonpolar microenvironment, which was further supported through peak-to-peak correlation of infrared analysis and fluorescence measurements. Moreover, the release profile of the as-obtained EZM-nanopowder increased significantly >98% in 30 min, which indicates that a reduced drug concentration will be needed for capsules or tablets in the future and can be simply incorporated into the multidosage formulation of EZM.

Fourth-Generation Antibiotic Gatifloxacin Encapsulated by Microemulsions: Structural and Probing Dynamics.

To overcome the increased disease rate, utilization of the versatile broad spectrum antibiotic drugs in controlled drug-delivery systems has been a challenging and complex consignment. However, with the development of microemulsion (µE)-based formulations, drugs can be effectively encapsulated and transferred to the target source. Herein, two biocompatible oil-in-water (o/w) µE formulations comprising clove oil/Tween 20/ethylene glycol/water (formulation A) and clove oil/Tween 20/1-butanol/water (formulation B) were developed for encapsulating the gatifloxacin (GTF), a fourth-generation antibiotic. The pseudoternary phase diagrams were mapped at a constant surfactant/co-surfactant (1:1) ratio to bound the existence of a monophasic isotropic region for as-formulated µEs. Multiple complementary characterization techniques, namely, conductivity (σ), viscosity (η), and optical microscopy analyses, were used to study the gradual changes that occurred in the microstructure of the as-formulated µEs, indicating the presence of a percolation transformation to a bicontinuous permeate flow. GTF showed good solubility, 3.2 wt % at pH 6.2 and 4.0 wt % at pH 6.8, in optimum µE of formulation A and formulation B, respectively. Each loaded µE formulation showed long-term stability over 8 months of storage. Moreover, no observable aggregation of GTF was found, as revealed by scanning transmission electron microscopy and peak-to-peak correlation of IR analysis, indicating the stability of GTF inside the formulation. The average particle size of each µE, measured by dynamic light scattering, increased upon loading GTF, intending the accretion of drug in the interfacial layers of microdomains. Likewise, fluorescence probing sense an interfacial hydrophobic environment to GTF molecules in any of the examined formulations, which may be of significant interest for understanding the kinetics of drug release.

Synthesis and Swelling Behavior of pH-Sensitive Semi-IPN Superabsorbent Hydrogels Based on Poly(acrylic acid) Reinforced with Cellulose Nanocrystals.

pH-sensitive poly(acrylic acid) (PAA) hydrogel reinforced with cellulose nanocrystals (CNC) was prepared. Acrylic acid (AA) was subjected to chemical cross-linking using the cross-linking agent MBA (N,N-methylenebisacrylamide) with CNC entrapped in the PAA matrix. The quantity of CNC was varied between 0, 5, 10, 15, 20, and 25 wt %. X-ray diffraction (XRD) data showed an increase in crystallinity with the addition of CNC, while rheology tests demonstrated a significant increase in the storage modulus of the hydrogel with an increase in CNC content. It was found that the hydrogel reached maximum swelling at pH 7. The potential of the resulting hydrogels to act as drug carriers was then evaluated by means of the drug encapsulation efficiency test using theophylline as a model drug. It was observed that 15% CNC/PAA hydrogel showed the potential to be used as drug carrier system.

Characterization and biocompatibility evaluation of bacterial cellulose-based wound dressing hydrogel: effect of electron beam irradiation doses and concentration of acrylic acid.

The use of bacterial cellulose (BC)-based hydrogel has been gaining attention owing to its biocompatibility and biodegradability. This study was designed to investigate the effect of radiation doses and acrylic acid (AA) composition on in vitro and in vivo biocompatibility of BC/AA as wound dressing materials. Physical properties of the hydrogel, that is, thickness, adhesiveness, rate of water vapor transmission, and swelling were measured. Moreover, the effect of these parameters on skin irritation and sensitization, blood compatibility, and cytotoxicity was studied. Increased AA content and irradiation doses increased the thickness, crosslinking density, and improved the mechanical properties of the hydrogel, but reduced its adhesiveness. The swelling capacity of the hydrogel increased significantly with a decrease in the AA composition in simulated wound fluid. The water vapor permeability of polymeric hydrogels was in the range of 2035-2666 [g/(m-2 day-1 )]. Dermal irritation and sensitization test demonstrated that the hydrogel was nonirritant and nonallergic. The BC/AA hydrogel was found to be nontoxic to primary human dermal fibroblast skin cells with viability >88% and was found to be biocompatible with blood with a low hemolytic index (0.80-1.30%). Collectively, these results indicate that these hydrogels have the potential to be used as wound dressings. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2553-2564, 2017.

A study on dispersion and characterisation of α-mangostin loaded pH sensitive microgel systems.

BACKGROUND: α-Mangostin was extracted with methanol from the rind of mangosteen fruit and purified by using silica gel column chromatography technique. The compound is characterised using infrared, (13)C and (1)H NMR as well as UV-vis spectroscopy. The α-mangostin dispersion in colloidal systems was studied by incorporating it with an ionic microgel, poly (N-Isopropylacrylamide)-co-2VP at different pH. RESULT: The DLS result showed the size of microgel-α-mangostin mixture declined from 548 nm to 200 nm upon the increment of the pH. Moreover, it was found the morphology of loaded compound depended largely on the nature of the continuous phase of the microgel system. Interestingly, by manipulating the pH, α-mangostin tends to form crystal at extremely low pH and transforms into spherical shapes at pH 6. CONCLUSION: This research shows different structures of the α-mangostin particle that are attributed by adjusting the pH using microgel systems as a template.