Nano Biocomposite Research Articles

Preparation and antibacterial properties of nano biocomposite Poly(ε-caprolactone)-SiO2 films with nanosilver

Two different silica samples with different particle size distributions (Silica-I: 40–63 μm, Silica-II: 90% below <55 μm) were utilized after the nano silver (5–30 nm) coating process by poly(dimethylsiloxane) in acetone. The prepared nano Ag-silica powders were melt-mixed into poly(e-caprolactone) (PCL) and the mixture was roll-milled to produce the nano biocomposite films containing 10%, 20% and 40% nano Ag-silica. The antibacterial activity of the composite films against E. coli was evaluated. For the PCL films with 40% Ag-silica (0.08–0.12% nanosilver), 100% reduction of the bacterial contamination was observed. The nanosilver coated silica particles could find applications in antibacterial nano biocomposites.

In vitro performance of a nanobiocomposite scaffold containing boron-modified bioactive glass nanoparticles for dentin regeneration.

Every year, many dental restoration methods are carried out in the world and most of them do not succeed. High cost of these restorations and rejection possibility of the implants are main drawbacks. For this reason, a regenerative approach for repairing the damaged dentin-pulp complex or generating a new tissue is needed. In this study, the potential of three-dimensional cellulose acetate/oxidized pullulan/gelatin-based dentin-like constructs containing 10 or 20% bioactive glass nanoparticles was studied to explore their potential for dentin regeneration. Three-dimensional nano biocomposite structures were prepared by freeze-drying/metal mold pressing methods and characterized by in vitro degradation analysis, water absorption capacity and porosity measurements, scanning electron microscopy, in vitro biomineralization analysis. During one-month incubation in phosphate buffered saline solution at 37°C, scaffolds lost about 25-30% of their weight and water absorption capacity gradually decreased with time. Scanning electron microscopy examinations showed that mean diameter of the tubular structures was about 420 µm and the distance between walls of the tubules was around 560 µm. Calcium phosphate precipitates were formed on scaffolds surfaces treated with simulated body fluid, which was enhanced by boron-modified bioactive glass addition. For cell culture studies human dental pulp stem cells were isolated from patient teeth. An improvement in cellular viability was observed for different groups over the incubation period with the highest human dental pulp stem cells viability on B7-20 scaffolds. ICP-OES analysis revealed that concentration of boron ion released from the scaffolds was between 0.2 and 1.1 mM, which was below toxic levels. Alkaline phosphatase activity and intracellular calcium amounts significantly increased 14 days after incubation with highest values in B14-10 group. Von Kossa staining revealed higher levels of mineral deposition in these groups. In this work, results indicated that developed dentin-like constructs are promising for dentin regeneration owing to presence of boron-modified bioactive glass nanoparticles.

Removal of Cr(VI) ions from the aqueous solution through nanoscale zero-valent iron (nZVI) Magnetite Corn Cob Silica (MCCS): A bio-waste based water purification perspective

In this work corn cob silica supported nanoscale zero-valent iron (MCCS), a nano biocomposite was developed by a facile technique and its efficiency was investigated for removal of hexavalent chromium Cr(VI) from aqueous solution. Batch adsorption studies were carried out to examine the influence of contact time and initial metal concentration and pH after characterization under field emission scanning electron microscopy (FE SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). The selective adsorption ability of MCCS towards Cr(VI), only 0.1g of adsorbent have shown effective adsorption of these ions with a maximum adsorption capacity (qm) of 11.1mgg−1. The studied results also reveal that the removal efficiency is highly dependent on solution pH and temperature and the sorption kinetics was best described by the pseudo-second order kinetic model. Since the magnetized nanocomposite can be easily isolated and removed using external magnets, there is future scope of using this novel adsorbent in various remediation techniques.

Nano modification of NZVI with an aquatic plant Azolla filiculoides to remove Pb(II) and Hg(II) from water: Aging time and mechanism study

This paper reports the preparation and stabilization of nano zero valent iron (NZVI) on a modified aquatic plant, Azolla filiculoides, and investigates its potential for the adsorption/reduction of Pb(II) and Hg(II) ions from aqueous media even after six months of storage in the lab condition. XRD, TEM and zeta potential results demonstrated that the Azolla-NaOH could be a good stabilizer of aged NZVI (six months) and the green support suppressed the oxidation and aggregation of immobilized NZVI. Kinetic and equilibrium models for lead and mercury ions uptake were developed by considering the effect of the initial Pb(II) and Hg(II) concentrations, contact time, adsorbent dosage, initial pH and effect of temperature. The contact time to obtain equilibrium for maximum uptake by Azolla-OH-NZVI was 20min. The removal of toxic metal ions has been monitored in terms of pseudo-first- and -second-order kinetics, and the Freundlich and Langmuir isotherms models have also been utilized to the equilibrium uptake results. The uptake kinetics followed the mechanism of the pseudo-second-order equation for all systems studied, confirming chemical sorption as the rate-limiting step of adsorption mechanisms and not involving a mass transfer in solution. The thermodynamic results confirmed that the uptake of Pb(II) and Hg(II) ions were feasible, spontaneous and endothermic at 25–80°C. XRD and zeta potential data displayed the existence of Pb(0) and Hg(0) on the Azolla-OH-NZVI surface. The nanobioadsorbent revealed high recyclability due to its reasonable uptake efficiency after 7th adsorption–desorption cycles. The proposed nano biocomposite could also be utilized to uptake Pb(II) and Hg(II) ions from the real water (Anzali lagoon water). However, coated NZVI with Azolla filiculoides as a green and environmentally friendly support suppressed rapid oxidation and aggregation of the immobilized NZVI, therefore vastly enhancing the probability of environmental transport and reducing the sedimentation and potential for toxicity.

Application of novel nanobiocomposites for removal of nickel(II) from aqueous environments: Equilibrium, kinetics, thermodynamics and ex-situ studies

The current study presents a novel approach for the removal of Ni(II) from aqueous environments using plant gum-based (PG) and clay-based (CL) nanobiocomposite (NBC) composed of ZnO nanoparticles and chitosan. Parameters like pH, contact time, temperature, initial metal concentration and adsorbent dosage were optimized. Under optimized conditions, maximum removal of Ni(II) was noted as 90.1% and 95.5% in the case of PG-NBC and CL-NBC, respectively. Equilibrium studies suggested a homogeneous mode of adsorption. Good linearity was observed for the pseudo-first order kinetic model, suggesting a physical mode of adsorption. Thermodynamic studies showed an endothermic and spontaneous nature of adsorption. The mechanism was further elucidated using SEM, EDX, AFM and FT-IR analysis. Ex-situ studies showed a maximum Ni(II) removal of 87.34% from electroplating wastewater using CL-NBC in column mode. Regeneration studies suggested that CL-NBC could be consistently reused up to 4 cycles.

Equilibrium, kinetics and thermodynamic study on adsorption of reactive blue-21 and reactive red-141 by chitosan-organically modified nanoclay (Cloisite 30B) nano-bio composite

The objective of this study was to investigate the use of nanobiocomposite (CC) containing Chitosan and Cloisite 30B an Organically modified Nanoclay to remove the dyes Reactive blue -21 and Reactive red-141.The effects of adsorbent dose, contact time, and concentration on the adsorption process were systematically studied. Isotherm models were applied to the experimental equilibrium data and various kinetic models were used to describe the kinetic data and evaluate of rate constants. The thermodynamic parameters associated with the adsorption process were calculated from Langmuir constant. The negative values of ∆G indicate that the overall adsorption processes are spontaneous. The adsorption process was found to be independent of temperature and the very low positive values of enthalpy further affirm this fact.

An elegant synthesis of chitosan grafted hydrotalcite nano-bio composite material and its effective catalysis for solvent-free synthesis of jasminaldehyde

A novel nano-bio composite of chitosan and a layered double hydroxide elegantly synthesized by a co-precipitation method had effectively and selectively catalysed the jasminaldehyde synthesis.

Synthesis and application of polypyrrole/carrageenan nano-bio composite as a cathode catalyst in microbial fuel cells

A novel nano-bio composite polypyrrole (PPy)/kappa-carrageenan(KC) was fabricated and characterized for application as a cathode catalyst in a microbial fuel cell (MFC). High resolution SEM and TEM verified the bud-like shape and uniform distribution of the PPy in the KC matrix. X-ray diffraction (XRD) has approved the amorphous structure of the PPy/KC as well. The PPy/KC nano-bio composites were then studied as an electrode material, due to their oxygen reduction reaction (ORR) ability as the cathode catalyst in the MFC and the results were compared with platinum (Pt) as the most common cathode catalyst. The produced power density of the PPy/KC was 72.1mW/m2 while it was 46.8mW/m2 and 28.8mW/m2 for KC and PPy individually. The efficiency of the PPy/KC electrode system is slightly lower than a Pt electrode (79.9mW/m2) but due to the high cost of Pt electrodes, the PPy/KC electrode system has potential to be an alternative electrode system for MFCs.

Collagen based magnetic nanobiocomposite as MRI contrast agent and for targeted delivery in cancer therapy

BackgroundIn this study, an attempt has been made with the advent of technology to prepare a multifunctional nanobiocomposite (NBC) for targeted drug delivery in cancer therapy. MethodsCollagen (C) was fabricated as nanofibers with multifunctional moieties viz. CFeAb*D by incorporating iron oxide nanoparticles (Fe), coupling with fluorescein isothiocyanate (FITC) labeled antibody (Ab*) and loading an anticancer gemcitabine drug (D). This NBC was characterized by conventional methods and evaluated for its biological activities. ResultsThe UV–vis and FTIR spectroscopic studies revealed the fluorescein to protein ratio and revealed the presence of iron oxide nanoparticles and their interaction with the collagen molecules, respectively. While SDS-PAGE showed the proteinaceous nature of collagen, VSM and TEM studies revealed magnetic saturation as 54.97emu/g and a magnetic nanoparticle with a diameter in the range of 10–30nm and the dimension of nanofiber ranging from 97 to 270nm. A MRI scan has shown a super paramagnetic effect, which reveals that the prepared NBC can be used as a MRI contrast agent. The MTT assay has shown biocompatibility and an apoptotic effect while phase contrast microscopy exhibited receptor mediated uptake of endocytosis. ConclusionThe novelty in the prepared NBC lies in the collagen nanofibers, which have a higher penetrating property without causing much cell damage, biocompatibility and multifunctional properties and is able to carry multifunctional agents. General significanceThe study has demonstrated the possible use of CFeAb*D as a multifunctional NBC for biomedical applications.

Functionalized Multi Walled Carbon Nanotubes Nano Biocomposite Film for the Amperometric Detection of L-Cysteine

The development of nano biocomposite film (f-MWCNTs-Au-GO(x)) for L-cysteine (LC) detection is proposed by using glassy carbon electrode (GCE). The proposed nano biocomposite film has been fabricated on ITO for scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis. Next, the f-MWCNTs-Au-GO(x) nano biocomposite film modified GCE's surface was examined by scanning electrochemical microscopy (SECM). The proposed nano biocomposite film has been successfully applied for the detection of LC using cyclic voltammetry (CV) and amperometry. The f-MWCNTs-Au-GO(x) film modified GCE exhibited a linear response for LC detection in the lower and higher concentrations ranges of 2 to 42 x 10(-6), 0.1 to 1.08 x 10(-3) mol L(-1). Also, the proposed nano biocomposite film possesses high sensitivity and good repeatability for LC detection.

Fabrication and biocompatibility of nano non-stoichiometric apatite and poly(ε-caprolactone) composite scaffold by using prototyping controlled process

Nano biocomposite scaffolds of non-stoichiometric apatite (ns-AP) and poly(epsilon-caprolactone) (PCL) were prepared by a prototyping controlled process (PCP). The results show that the composite scaffolds with 40 wt% ns-AP contained open and well interconnected pores with a size of 400-500 mum, and exhibited a maximum porosity of 76%. The ns-AP particles were not completely embedded in PCL matrix while exposed on the composite surface, which might be useful for cell attachment and growth. Proliferation of MG(63) cells was significantly better on the composite scaffolds with porosity of 76% than that those with porosity of 53%, indicating that the scaffolds with high porosity facilitated cell growth, and could promote cell proliferation. The composite scaffolds were implanted into rabbit thighbone defects to investigate the in vivo biocompatibility and osteogenesis. Radiological and histological examination confirmed that the new bony tissue had grown easily into the entire composite scaffold. The results suggest that the well-interconnected pores in the scaffolds might encourage cell proliferation, and migration to stimulate cell functions, thus enhancing bone formation in the scaffolds. This study shows that bioactive and biocompatible ns-AP/PCL composite scaffolds have potential applications in bone tissue engineering.

Preliminary investigation of bioactivity of nano biocomposite

Bioactive biomaterials can form a bone-like apatite layer on their surfaces in the body, which is critical to establishing bone bonding between bioactive materials and living tissue. At present study, the bone-like apatite formation in vitro and vivo on the surface of the nano apatite/polyamide composite was studied, and the bioactive composites implanted into the femora of rabbits were also investigated. The results revealed that the bone-like apatite containing carbonate can form on the surface of the biocomposite both in SBF and dorsal muscle of rabbits, and the composite would form directly combination with the natural bone without fibrous capsule tissue between implant and host bone tissue. All of these indicated that the nano biocomposites have excellent bioactivity and can be used for bone replacement.