High-Power Ultrasonic Synthesis and Magnetic-Field-Assisted Arrangement of Nanosized Crystallites of Cobalt-Containing Layered Double Hydroxides

One-Dimensional Nanoscale Si/Co Based on Layered Double Hydroxides towards Electrochemical Supercapacitor Electrodes

It is well known that layered double hydroxides (LDHs) are two-dimensional (2D) layered compounds. However, we modified these 2D layered compounds to become one-dimensional (1D) nanostructures destined for high-performance supercapacitors applications. In this direction, silicon was inserted inside the nanolayers of Co-LDHs producing nanofibers of Si/Co LDHs through the intercalation of cyanate anions as pillars for building nanolayered structures. Additionally, nanoparticles were observed by controlling the preparation conditions and the silicon percentage. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermal analyses have been used to characterize the nanolayered structures of Si/Co LDHs. The electrochemical characterization was performed by cyclic voltammetry and galvanic charge–discharge technique in 2M KOH electrolyte solution using three-electrode cell system. The calculated specific capacitance results indicated that the change of morphology from nanoparticles or plates to nanofibers had a positive effect for improving the performance of specific capacitance of Si/Co LDHs. The specific capacitance enhanced to be 621.5 F g−1 in the case of the nanofiber of Si/Co LDHs. Similarly, the excellent cyclic stability (84.5%) was observed for the nanofiber. These results were explained through the attribute of the nanofibrous morphology and synergistic effects between the electric double layer capacitive character of the silicon and the pseudo capacitance nature of the cobalt. The high capacitance of ternary Si/Co/cyanate LDHs nanocomposites was suggested to be used as active electrode materials for high-performance supercapacitors applications.

A Novel Para-Amino Salicylic Acid Magnesium Layered Hydroxide Nanocomposite Anti-Tuberculosis Drug Delivery System with Enhanced in vitro Therapeutic and Anti-Inflammatory Properties

INTRODUCTION

Mycobacterium tuberculosis infections are associated with severe local inflammatory reactions, which may be life-threatening and lead to tuberculosis pathogenesis and associated complications. Inorganic nanolayers have been vastly exploited for biomedical applications (especially in drug delivery) because of their biocompatible and biodegradable nature with the ability to release a drug in a sustained manner. Herein, we report a new nanodelivery system of inorganic nanolayers based on magnesium layered hydroxides (MgLH) and a successfully intercalated anti-tuberculosis drug para-aminosalicylic acid (PAS).

METHODS

The designed anti-tuberculosis nanodelivery composite, MgLH-PAS, was prepared by a novel co-precipitation method using MgNO3 as well MgO as starting materials.

RESULTS

The designed nano-formulation, PAS-MgLH, showed good antimycobacterial and antimicrobial activities with significant synergistic anti-inflammatory effects on the suppression of lipopolysaccharide (LPS) stimulated inflammatory mediators in RAW 264.7 macrophages. The designed nano-formulation was also found to be biocompatible with human normal lung cells (MRC-5) and 3T3 fibroblast cells. Furthermore, the in vitro release of PAS from PAS-MgLH was found to be sustained in human body simulated phosphate buffer saline (PBS) solutions of pH 7.4 and pH 4.8.

DISCUSSION

The results of the present study are highly encouraging for further in vivo studies. This new nanodelivery system, MgLH, can be exploited in the delivery of other drugs and in numerous other biomedical applications as well.