Faruq Mohammad

Mechanical, morphological and structural properties of cellulose nanofibers reinforced epoxy composites

Present study, deals about isolation and characterization of cellulose nanofibers (CNFs) from the Northern Bleached Softwood Kraft (NBSK) pulp, fabrication by hand lay-up technique and characterization of fabricated epoxy nanocomposites at different filler loadings (0.5%, 0.75%, 1% by wt.). The effect of CNFs loading on mechanical (tensile, impact and flexural), morphological (scanning electron microscope and transmission electron microscope) and structural (XRD and FTIR) properties of epoxy composites were investigated. FTIR analysis confirms the introduction of CNFs into the epoxy matrix while no considerable change in the crystallinity and diffraction peaks of epoxy composites were observed by the XRD patterns. Additions of CNFs considerably enhance the mechanical properties of epoxy composites but a remarkable improvement is observed for 0.75% CNFs as compared to the rest epoxy nanocomposites. In addition, the electron micrographs revealed the perfect distribution and dispersion of CNFs in the epoxy matrix for the 0.75% CNFs/epoxy nanocomposites, while the existence of voids and agglomerations were observed beyond 0.75% CNFs filler loadings. Overall results analysis clearly revealed that the 0.75% CNFs filler loading is best and effective with respect to rest to enhance the mechanical and structural properties of the epoxy composites.

Development of PANI/MWCNTs decorated with cobalt oxide nanoparticles towards multiple electrochemical, photocatalytic and biomedical application sites

In the present work, a ternary nanocomposite of Co3O4doped/PANI/MWCNTs (cobalt oxide-doped polyaniline multi-walled carbon nanotubes) was synthesized via the in situ oxidative polymerization of aniline. The composite was fully characterized using instrumental analysis, and further tested for its potential in electrochemical, photocatalytic and biomedical applications. The Co oxide nanoparticles were first synthesized using the sol–gel approach in the presence of starch as a capping agent so as to prevent agglomeration and characterized using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), EDX, elemental mapping and high-resolution transmission electron microscopy (HRTEM). For the measurement of electrochemical activity, the electrodes were synthesized with MWCNTs and functionalized with a conducting polymer (PANI). For the composite, the Co metal oxide provides a pseudo-capacitance which, in general, improves the performance characteristics of the electrode and has been the focus of many researchers. Further, the specific capacitance of the prepared composite was tested using cyclic voltammetry (CV) and impedance spectroscopy. The capacitive studies reveal that the composite has a synergistic effect and is observed to have the highest specific capacitance of 382 F g−1 run at a scan rate of 10 mV s−1. The composite was also found to have excellent photocatalytic degradation properties and outstanding antibacterial activity against both Gram positive and Gram negative bacterial strains. The minimum MIC (6.25 μg mL−1) and MBC (12.5 μg mL−1) values against E. coli and maximum values against B. amyloliquefaciens (25 and 50 μg mL−1) at fourth dilution were observed. Furthermore, the anticancer efficiency of the composite was tested by making use of two different cancer cell types (MCF-7 and MDA-MB-231) confirming the importance of its biological activity for biomedical applications.

Sustained drug release and electrochemical performance of ethyl cellulose-magnesium hydrogen phosphate composite

In this, a sol-gel method was applied to prepare ethyl cellulose-magnesium hydrogen phosphate (EC-MgHPO4) composite that can have potential applications in the sensory, pharmaceutical, and biomedical sectors. The formed composite was thoroughly characterized by making use of the instrumental analysis such as UV-Vis, FT-IR, HRTEM, EDAX, SEM and XRD. For the composite, the other parameters determined includes the water uptake, porosity, thickness, bulk and tapped densities, angle of repose, Carrs index and Hausner ratio. From the results, the material found to exhibit good flowing properties with a Carrs index of 11.11%, Hausner ratio of 1.125, and angle of response of 33°. The EDAX spectrum and HRTEM analysis confirmed for the composite formation and the particles size is investigated to be around 52nm. The surface porosity due to the EC matrices was confirmed by the SEM analysis, which further used for the loading of drug, Proguanil. In addition, the materials conductivity was studied by taking uni-univalent electrolyte solution (KCl and NaCl) indicated that the conductivity follows the order of KCl>NaCl, while the activation energy obtained from Arrhenius method resembled that the conductivity is strongly influenced by the electrolyte type used. We found from the analysis that, with a decrease in the size of hydrated radii of ions, the conductivity of EC-MgHPO4 material also observed to be decreased in the order K+>Na+ and the material proved to be mechanically stable and can be operated over a range of pHs, temperatures, and electrolyte solutions. Further, the drug loading and efficiency studies indicated that the material can trap up to 80% of Proguanil (antimalarial drug) applied for its loading. The Proguanil drug release profiles confirmed for the controlled and sustained release from the EC-MgHPO4 matrix, as the material can release up to 87% of its total loaded drug over a 90min period. Finally, the cell viability and proliferation studies tested against two different cell cultures of BRL-3A rat liver and H9c2 cardiomyoblasts indicated the non-toxic nature and safer applicability of the EC-MgHPO4 (25-500μg/mL, 24h). Overall, the results of the study confirm for the safer applicability of the composite towards biosensor, drug delivery, scaffolding, and bioanalytical (quality control) applications.

Iminodiacetic acid modified kenaf fiber for waste water treatment

In the present study, iminodiacetic acid (IDA)-modified kenaf fiber, K-IDA formed by the chemical modification of plant kenaf biomass was tested for its efficacy as a sorbent material towards the purification of waste water. The K-IDA fiber was first characterized by the instrumental techniques like Fourier transform infrared (FTIR) analysis, elemental analysis (CHNSO), and scanning electron microscopy (SEM). On testing for the biosorption, we found that the K-IDA has an increment in the adsorption of Cu2+ ions as compared against the untreated fiber. The Cu2+ ions adsorption onto K-IDA fits very well with the Langmuir model and the adsorption maximum achieved to be 91.74mg/g. Further, the adsorption kinetics observed to be pseudo second-order kinetics model and the Cu2+ ions adsorption is a spontaneous endothermic process. The desorption study indicates a highest percentage of Cu2+ of 97.59% from K-IDA under 1M HCl solution against H2SO4 (72.59%) and HNO3 (68.66%). The reusability study indicates that the efficiency did not change much until the 4th cycle and also providing enough evidence for the engagement of our biodegradable K-IDA fiber towards the removal of Cu2+ ions in real-time waste water samples obtained from the electroplating and wood treatment industries.

Luteinizing hormone-releasing hormone targeted superparamagnetic gold nanoshells for a combination therapy of hyperthermia and controlled drug delivery

In this, we developed superparamagnetic iron oxide nanoparticles (SPIONs) to be appropriate for the diagnosis and treatment of cancer cells by means of magnetic resonance imaging (MRI) and magnetically controlled hyperthermia/drug delivery (respectively). For the preparation of composite, we started with SPIONs, followed by its coating with gold to form SPIONs@Au, which further conjugated with luteinizing hormone-releasing hormone (LHRH) protein by making use of the cysteamine (Cyst) space linker and finally loaded with 5-Fluororacil (5-Fu) anticancer drug to form SPIONs@Au-Cyst-LHRH_5-Fu composite. Thus formed composite was thoroughly characterized by making use of the instrumental analysis such as HRTEM, EDAX, DLS, TGA, XPS, UV-vis, FTIR, HPLC and SQUID magnetics. We found from the analysis that the particles are spherical in shape, monodispersed with a size distribution of around 6.9nm in powdered dry form, while in solution phase it is 8.7nm. The UV-vis, FTIR, and HPLC studies confirmed for the loading of the 5-Fu drug onto the surface of SPIONs core and the maximum amount of drug that got adsorbed to be about 42%. The SQUID magnetic studies provided the information for the superparamagnetic behavior of the drug loaded SPIONs and the saturation magnetization (Ms) values observed to be about 11emu/g and the blocking temperature (TB) of 348K. On testing the particles to see the effects of magnetic fluid hyperthermia (MFH) due to some changes in the solvent medium and oscillating frequency, the material seems to be highly active in aqueous medium and the activity gets increased with respect to the applied frequency of oscillation (430Hz>230Hz>44Hz). From the heat release studies, the calculated specific power loss (SPL) values for the SPIONs@Au-Cyst-LHRH_5-Fu composite are at the highest of 1068W/g in water (430Hz) vs the least of 68W/g in toluene (44Hz). Further, the drug release studies tested under the influence of magnetic field provided the information that the composite released its entire loaded drug following an exposure to the magnetic field (430Hz over 4h time), while only 53% (over 5h) for the controlled measurements of no magnetic field, thereby supporting to have the magnetic field so as to observe the externally controlled drug release effects. Finally, the results of the study provide the information that the SPIONs@Au-Cyst-LHRH_5-Fu composite can be potential for theranostic applications of cancer through the phenomenon of applying for MRI, magnetically controlled hyperthermia and drug delivery externally.

Histological analysis of anti-cancer drug loaded, targeted Mn:ZnS quantum dots in metastatic lesions of 4T1 challenged mice

Abstract5-Fluororaucil (5-FU) as anti-cancer drug was reported to induce thymidine synthase (TS) overexpression and cancer cell resistance. To improve its therapeutic efficacy and selective targeting, here we developed a targeted delivery system mediated by the active ligand-folate receptor chemistry to deliver the 5-FU drug selectively into the tumor microenvironment. The preparation was achieved by exploring chitosan (CS)-biopolymer based system with folic acid (FA)-conjugation. The 5-FU@FACS-Mn:ZnS quantum dots (QDs) based on the histological assessment conducted in the 4T1 challenged mice showed an improved tumor remission in the liver, spleen and lungs. The 5-FU@FACS-Mn:ZnS composite induced anti-proliferative properties in these organs as compared to the free 5-FU drug. Unlike the 5-FU@FACS-Mn:ZnS treated groups which showed some specific morphological changes such as cell shrinkage without obvious presence of adipocytes, the excised section of the tumor in the untreated control group and the free 5-FU drug treated group showed necrotic and degenerated cells; these cells are multifocally distributed in the tumor mass with evidence of widely distributed adipocytes within the tumor mass. These findings suggest that the 5-FU@FACS-Mn:ZnS composite has a superior role during the induction of apoptosis in the 4T1 cells as compared to the free 5-FU drug treated groups. The results of the study therefore suggest that the impregnation of 5-FU anti-cancer drug within the FACS-Mn:ZnS system significantly improves its selective targeting efficacy, in addition to improving the anti-proliferative properties and attenuate possible tumor resistances to the 5-FU drug.Graphical abstractThe work discusses about the anti-metastatic effects of folic acid-bound 5-Fluororacil loaded Mn:ZnS quantum dots towards 4T1 cell line proliferation in mice based on the histological analysis.