Combined Use Of Nanoparticles Research Articles

Enhancing engine performance, combustion, and emissions characteristics through CeO2-modified cottonseed biodiesel with hydrogen enrichment: A comprehensive investigation

This investigation delves into the combined use of nanoparticles added biodiesel blends and hydrogen as secondary fuels in CI engines, intending to minimize the reliance on traditional fossil fuels. Calcined wood ash (CWA) has been used as a heterogeneous catalyst for the preparation of cottonseed biodiesel. XRD, SEM and BET analysis was performed to characterize the catalyst. This study evaluates the impact of adding hydrogen and Cerium oxide (CeO2) nanoparticles to cottonseed biodiesel on a CRDI engine. It showed that H2 at an intake rate of 10 L/min improved the engine's overall performance and reduced hazardous emissions. By incorporating the CeO2 nanoparticles (75 ppm) in a cottonseed biodiesel blend and injecting H2 in the engine the BTE was enhanced by 27.8% and BSFC was decreased by 4.41%. There was a reduction of 24%, 22.8%, 6.42%, and 69.5% for HC, CO, CO2 and smoke emissions. On the other hand, NOx rose by 9.3% compared to diesel. The combustion characteristics, such as cylinder pressure showed 26.5% improvement at full load on inclusion of H2. Additionally, under maximum load, the blend C20 + CeO2+H2 has the shortest ignition delay and combustion duration leading to higher engine efficiency. The results of this investigation offer valuable insights into the potential of biodiesel-hydrogen dual-fuel strategies to reduce the environmental impact of CI engines while promoting sustainable energy practices.

Використання наночастинок і нанотехнологій у картоплярстві

Goal. To analyze the literature data and the results of their own research on the use of nanoparticles and nanotechnologies in potato growing, as well as the results of the combined use of nanoparticles and microbial preparations. Methods. Analysis of literature, virological, microbiological, instrumental, field experiment, biochemical, statistical, and economic analysis. Results. Nanoparticles with virulicidal, bactericidal and fungicidal activity, as well as those that stimulate the growth of bacteria, were determined in vitro. Thus, Ti nanoparticles, the composition of Se + I nanoparticles, and the drug «Avatar-2 Zahyst» obtained by the nanotechnological method had virulicidal activity against the phytopathogenic virus Potato virus Y in the conditions of vegetation experiments. Using the method of transmission electron microscopy, it was established that Ti nanoparticles can concentrate around Potato virus Y virions and adsorb on their surface, this can be a potential explanation for their virulicidal activity. Zn nanoparticles exhibit bactericidal activity against strains of beneficial soil bacteria Bacillus subtilis IMV B7023 and Pseudomonas chlororaphis subsp. aureofaciens ICM B306 (2687) and a strain of bacteria pathogenic for potatoes — Clavibacter michiganensis subsp. sepedonicus Ac1995, reducing their titer by 100%. The composition of Se + I nanoparticles to one degree or another increases the titer of all tested strains of beneficial soil and phytopathogenic bacteria, in particular the strain Bacillus subtilis IMV B7023, which is one of the bioagents of the microbial preparation «Azogran», by 8.46–20.36%. Also, the composition of Se + I nanoparticles showed the strongest antifungal activity, reducing the diameter of colonies of strains of phytopathogenic fungi Fusarium sp. 072 by 25.26–51.75%, Acremonium cucurbitacearum 502 — by 78.95–94.22, and Acremonium strictum 048 — by 52.67–75.00%, as well as the number of colonies of the strain Acremonium cucurbitacearum 502 — by 60,00-86.67%. These properties of nanoparticles, their compositions, and the drug «Avatar-2 Zahyst» were tested in the conditions of a field experiment, and the combined use of nanoparticles with the microbial drug «Azogran» was also investigated. The drug «Avatar-2 Zahyst» was effective against viral, bacterial, and fungal diseases. The combination of the drug «Azogran» with the composition of Se+I nanoparticles turned out to be the best, reducing the frequency of establishment of bacterial and fungal diseases and the degree of their damage, increasing the marketability of tubers, yield, and improving other indicators. In this option, the highest calculated profitability, the value of which was 111.7 and 75.8% in two areas, which is more than in the control by 57.7 and 41.5%, respectively. Among other options, it is worth highlighting the composition of Se + I nanoparticles and the drug «Azogran», however, their effects individually were smaller than in combination. Conclusions. The effectiveness of the composition of Se+I nanoparticles, «Avatar-2 Zahyst» and «Azogran» preparations for the control of potato infectious diseases and the prospects of their use in potato cultivation technology were proven. The positive effect of the composition of Se + I nanoparticles and the drug «Azogran» on the marketability of tubers and yield was shown. The synergy between the composition of Se + I nanoparticles and the drug «Azogran» was established. The most promising was the combined use of nanoparticles and microbial preparations in the technology of growing potatoes.

Cellulose Hydrogels Containing Geraniol and Icaridin Encapsulated in Zein Nanoparticles for Arbovirus Control.

The most important arboviruses are those that cause dengue, yellow fever, chikungunya, and Zika, for which the main vector is the Aedes aegypti mosquito. The use of repellents is an important way to combat mosquito-borne pathogens. In this work, a safe method of protection employing a repellent was developed based on a slow release system composed of zein nanoparticles containing the active agents icaridin and geraniol incorporated in a cellulose gel matrix. Analyses were performed to characterize the nanoparticles and the gel formulation. The nanoparticles containing the repellents presented a hydrodynamic diameter of 229 ± 9 nm, polydispersity index of 0.38 ± 0.10, and zeta potential of +29.4 ± 0.8 mV. The efficiencies of encapsulation in the zein nanoparticles exceeded 85% for icaridin and 98% for geraniol. Rheological characterization of the gels containing nanoparticles and repellents showed that the viscoelastic characteristic of hydroxypropylmethylcellulose gel was preserved. Release tests demonstrated that the use of nanoparticles in combination with the gel matrix led to improved performance of the formulations. Atomic force microscopy analyses enabled visualization of the gel network containing the nanoparticles. Cytotoxicity assays using 3T3 and HaCaT cell cultures showed low toxicity profiles for the active agents and the nanoparticles. The results demonstrated the potential of these repellent systems to provide prolonged protection while decreasing toxicity.

A comprehensive review of impacts of diverse nanoparticles on growth, development and physiological adjustments in plants under changing environment

The application of nanotechnology in agriculture includes the use of nanofertilizers, nanopesticides, and nanoherbicides that enhance plant nutrition without disturbing the soil texture and protect it against microbial infections. Thus, nanotechnology maintains the plant's health by maintaining its soil health. The use of nanoparticles (NPs) in agriculture reduces the chemical spread and nutrient loss and boosts crop yield and productivity. Effect of NPs varies with their applied concentrations, physiochemical properties, and plant species. Various NPs have an impact on the plant to increase biomass productivity, germination rate and their physiology. Also, NPs change the plant molecular mechanisms by altering gene expression. Metal and non-metal oxides of NPs (Au, Ag, ZnO, Fe2O3, TiO2, SiO2, Al2O3, Se, carbon nanotubes, quantum dots) exert an important role in plant growth and development and perform an essential role in stress amelioration.On the other hand, other effects of NPs have also been well investigated by observing their role in growth suppression and inhibition of chlorophyll and photosynthetic efficiency. In this review, we addressed a description of studies that have been made to understand the effects of various kind of NPs, their translocation and interaction with the plants. Also, the phytoremediation approaches of contaminated soil with combined use of NPs for sustainable agriculture is covered.

A Monte Carlo Study on Dose Enhancement in the Presence of Nanoparticles by Photon Source: A Comparison between Various Concentration and Material of Nanoparticles

Purpose: Recently, the application of high atomic number nanoparticles is suggested in the field of radiotherapy to improve physical dose enhancement and hence treatment efficiency. Several factors such as concentration and material of nanoparticles and energy of beam define the amount of dose enhancement in the target in the presence of nanoparticles. Materials and Methods: In this approach, a spherical cell was simulated through the Geant4 Monte Carlo toolkit which contained a nucleus and nanoparticles distributed through the cell. To investigate the effect of the concentration of nanoparticles on the deposited dose, it ranged from 3 mg/g to 30 mg/g for different materials like gold, silver, gadolinium, and platinum. Also, various mono-energetic photon beams included low and high energy sources were applied. Results: The results proved that as the concentration increased, the Dose Enhancement Factor (DEF) enlarged. Overall, almost for all energy and material that were used in this study, the maximum of DEF values occurred in the concentration of 30 mg/g. Moreover, lower energy sources presented higher DEF compared to other sources. The results indicated that the highest amount of DEF transpired for 35 keV photon beams equal to 14.67. Also, the K-edge energy of each material affects DEF values. Conclusion: To obtain a better outcome in the use of nanoparticles in combination with radiotherapy, a higher concentration of nanoparticles and low-energy photons should be considered to optimize the DEF and thus the treatment ratio.

The influence of nanoparticles, multicomponent microelemental fertiliser “Avatar-2 Zahyst” and microbial fertiliser “Azogran” on the yield of potato variety “Suvenir Chernihivsky” in Polissya

Improving traditional potato growing technology is of great scientific and practical importance for agriculture. Recently, nanoparticles (NPs) have been catching the attention of scientists as a promising means of increasing crop productivity. It has been established that NPs of such chemical elements as Fe, Zn, B, Si, Cu, Co, Se, and Ag can significantly increase the productivity of potatoes. It is known that Ag NPs show synergism with some microbial agents. However, the effect of NP of such elements as Zn and Se on potato yield and NPs combined with microbial agents for pre-sowing fertilisation has not been studied sufficiently. The influence of Ti and I NPs on potato yield, the influence of ELs on the yield of domestic potato varieties, and the influence of ELs on potato yield in Polissya are not yet studied. The purpose of the study was to investigate the effect of pre-sowing fertilisation of potatoes with Zn NPs, Ti NPs, Se + I NPs, Zn + Ti + Se + I NPs, multicomponent microelement fertiliser “Avatar-2 Zahyst”, microbial fertiliser “Azogran” and a combination of microbial fertiliser “Azogran” with Se + I NPs on the yield of potato variety “Suvenir Chernihivsky” in Polissya. For three years in a row, small-scale experiments were set up on sod-podzolic soil and leached chernozem. The plots were located on the land of the Institute of Agricultural Microbiology and Agricultural Production of the National Academy of Agrarian Sciences in Chernihiv Oblast. The data obtained on the potato harvest was analysed in accordance with generally accepted methods of statistical analysis. It was found that among all variants of pre-sowing fertilisation, the composition of Se + I NPs, the microbial fertiliser Azogran and the combination of Azogran with the composition of Se + I NPs had the greatest effect on the yield of potatoes of the Suvenir Chernihivsky variety on sod-podzolic soil by 33.13, 38.34 and 45.35%, respectively, and on leached chernozem by 10.97, 17.98 and 37.27%. It was found that the composition of Se + I nanoparticles and Azogran exhibit synergism. The data obtained indicate high prospects for the use of NPs in combination with microbial fertilisers in potato cultivation

Nanoparticles and their effects on differentiation of mesenchymal stem cells.

ABSTRACTOver the past decades, advancements in nanoscience and nanotechnology have resulted in numerous nanomedicine platforms. Various nanoparticles, which exhibit many unique properties, play increasingly important roles in the field of biomedicine to realize the potential of nanomedicine. Due to the capacity of self-renewal and multilineage mesenchymal differentiation, mesenchymal stem cells (MSCs) have been widely used in the area of regenerative medicine and in clinical applications due to their potential to differentiate into various lineages. There are several factors that impact the differentiation of MSCs into different lineages. Many types of biomaterials such as polymers, ceramics, and metals are commonly applied in tissue engineering and regenerative therapies, and they are continuously refined over time. In recent years, along with the rapid development of nanotechnology and nanomedicine, nanoparticles have been playing more and more important roles in the fields of biomedicine and bioengineering. The combined use of nanoparticles and MSCs in biomedicine requires greater knowledge of the effects of nanoparticles on MSCs. This review focuses on the effects of four inorganic or metallic nanoparticles (hydroxyapatite, silica, silver, and calcium carbonate), which are widely used as biomaterials, on the osteogenic and adipogenic differentiation of MSCs. In this review, the cytotoxicity of these four nanoparticles, their effects on osteogenic/adipogenic differentiation of MSCs and the signalling pathways or transcription factors involved are summarized. In addition, the chemical composition, size, shape, surface area, surface charge and surface chemistry of nanoparticles, have been reported to impact cellular behaviours. In this review, we particularly emphasize the influence of their size on cellular responses. We envision our review will provide a theoretical basis for the combined application of MSCs and nanoparticles in biomedicine.

Monte Carlo simulation and analytical calculation methods to investigate the potential of nanoparticles for INTRABEAM® IORT machine

In the present study, Monte Carlo (MC) simulation and analytical calculation methods were used to investigate the potential of cancer treatment for the combination of IORT with nanoparticles (NPs). The Geant4 MC toolkit was used to simulate ZEISS INTRABEAM® IORT machine and its smallest applicator with 1.5 cm diameter. The dose enhancement effects (DEFs) were obtained for silver (Ag), gold (Au), bismuth (Bi), copper (Cu) and iron (Fe) spherical NPs considering different concentrations. In addition, analytical calculations were performed based on attenuation coefficient formula for sample NPs. Our MC results showed that the use of different NPs led to an increase in DEF up to 40%. Among different NPs, Au had the maximum DEF. In addition, analytical calculations revealed a significant increase, using NPs as well. Our study has suggested that the use of NPs in combination with IORT has the potential to enhance treatment outcomes.

THE RESULTS OF THE RESEARCH ACTIVITY OF SILVER. NANOPARTICLES IN VITRO AND IN VIVO AGAINST DRUG- RESISTANT MYCOBACTERIUM TUBERCULOSIS STRAINS

The paper presents the results of experimental studies on the antitubercular activity of silver nanoparticles. In vitro experiments on 117 MBT strains with resistance to isoniazid and other drugs with preserved sensitivity to rifampin (group 1) and 108 ml of MBT strains (group 2), bactericidal action of nanoparticles was demonstrated in 48,1 and 41,7 % of cases, respectively. With the combined use of nanoparticles with isoniazide, similar indicators were 65,3 and 60,5 %, respectively (p < 0.05). In the model of experimental tuberculosis in BALB/C mice, the best survival and seeding rates of the pathogen from the lung tissue were also observed with the combined use of nanoparticles and isoniazide. The results obtained allow us to offer silver nanoparticles as adjuvants of chemotherapy for clinical trials.

The negative effect of silica nanoparticles on adipogenic differentiation of human mesenchymal stem cells

Nanoparticles have drawn much attention for a wide variety of applications in biomedical and bioengineering fields. The combined use of nanoparticles and human mesenchymal stem cells (hMSCs) in tissue engineering and regenerative medicine requires more knowledge of the influence of nanoparticles on cell viability and differentiation potential of hMSCs. The objective of this study is to investigate the in vitro uptake of silica nanoparticles (silica NPs) and their effect on adipogenic differentiation of hMSCs. After exposure of hMSCs to silica NPs, the uptake and localization of silica NPs were assessed using transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The adipogenic differentiation potential of hMSCs was examined by analyzing the formation and accumulation of lipids droplets, triglyceride (TG) content and the expression of adipogenic marker genes/proteins. The results showed that silica NPs did not affect the cell viability but significantly decreased the differentiation of hMSCs to adipocytes. These findings improve the understanding of the influence of silica NPs on adipogenic differentiation of hMSCs and will provide a reference for the applications of silica NPs in biomedical and bioengineering fields.

DEVELOPING NEW METHODS OF SPINAL CORD INJURY TREATMENT USING MAGNETIC NANOPARTICLES IN COMBINATION WITH ELECTROMAGNETIC FIELD

ABSTRACT Objective: To determine the amount of loss of function after spinal cord transection of varying extents, and whether magnetic iron oxide nanoparticles, in combination with an external magnetic field, improve the rate of subsequent functional recovery in rats. Methods: The animals were divided into groups with 50%, 80% and complete spinal cord transection. The animals of all three study groups were administered magnetic iron oxide nanoparticle suspension to the area of injury. The three control groups were not administered magnetic nanoparticles, but had corresponding transection levels. All animals were exposed to a magnetic field for 4 weeks. Loss of postoperative function and subsequent recovery were assessed using the BBB motor function scale and somatosensory evoked potential monitoring on the first day after surgery, and then weekly. Terminal histological analysis was also conducted in all the groups. Results: The animals in the control or complete transection groups did not demonstrate statistically significant improvement in either the BBB scores or evoked potential amplitude over the four-week period. In the group with 50% transection, however, a statistically significant increase in evoked potential amplitude and BBB scores was observed four weeks after surgery, with the highest increase during the second week of the study. In the group with 80% transection, only improvement in evoked potential amplitude was statistically significant, although less pronounced than in the 50% transection group. Conclusion: The use of magnetic iron oxide nanoparticles in combination with a magnetic field leads to higher rates of functional recovery after spinal cord injury in laboratory animals. The mechanism of this functional improvement needs further investigation.

Nanoparticles for radiation therapy enhancement

Nanoparticles (NPs) have been used for drug delivery, for in vitro diagnosis and for in vivo imaging. During the last decades, efforts have been made for the use of nanoparticles as therapeutic agents. Given that radiation therapy is not a selective antitumor treatment, the main challenge is to increase its therapeutic efficacy and thus to increase the differential radiation effect between healthy and cancer cells by the combined use of NPs. In the many research projects that have been contacted the last years, different nanoparticle designs and materials have been employed but the main idea is the use of high-Z NPs for radiosensitization. In this context, these NPs can intensify the production of secondary electrons and ROS that in turn enhance radiation therapy effects. The enhancement of radiotherapy efficiency could be evaluated by the determination of the Nanoparticle-mediated Enhancement Ratio (NER) after a single radiation dose, the determination of the Dose Modifying Factor (DMF) based on survival curves and the variation of the ROS production upon irradiation. This review will focused on the different approaches followed on the use of nanoparticles, the dosimetric studies available, the radiobiological issues and the target selectivity. Discussion will be made on the efficiency and the prospective of the use of NPs in current radiotherapy practice. Nanoparticles (NPs) have been used for drug delivery, for in vitro diagnosis and for in vivo imaging. During the last decades, efforts have been made for the use of nanoparticles as therapeutic agents. Given that radiation therapy is not a selective antitumor treatment, the main challenge is to increase its therapeutic efficacy and thus to increase the differential radiation effect between healthy and cancer cells by the combined use of NPs. In the many research projects that have been contacted the last years, different nanoparticle designs and materials have been employed but the main idea is the use of high-Z NPs for radiosensitization. In this context, these NPs can intensify the production of secondary electrons and ROS that in turn enhance radiation therapy effects. The enhancement of radiotherapy efficiency could be evaluated by the determination of the Nanoparticle-mediated Enhancement Ratio (NER) after a single radiation dose, the determination of the Dose Modifying Factor (DMF) based on survival curves and the variation of the ROS production upon irradiation. This review will focused on the different approaches followed on the use of nanoparticles, the dosimetric studies available, the radiobiological issues and the target selectivity. Discussion will be made on the efficiency and the prospective of the use of NPs in current radiotherapy practice.

Investigating the role of surface micro/nano structure in cell adhesion behavior of superhydrophobic polypropylene/nanosilica surfaces

The main aim of the current study was to investigate the effects of different topographical features on the biological performance of polypropylene (PP)/silica coatings. To this end, a novel method including combined use of nanoparticles and non-solvent was used for preparation of superhydrophobic PP coatings. The proposed method led to a much more homogeneous appearance with a better adhesion to the glass substrate. Moreover, a notable reduction was observed in the required contents of nanoparticles (100–20wt% with respect to the polymer) and non-solvent (35.5–9vol%) for achieving superhydrophobicity. Surface composition and morphology of the coatings were also investigated via X-ray photoelectron spectroscopy and scanning electron microscopy. Based on both qualitative and quantitative evaluations, it was found that the superhydrophobic coatings with only nano-scale roughness strongly prevented adhesion and proliferation of 4T1 mouse mammary tumor cells as compared to the superhydrophobic surfaces with micro-scale structure. Such results demonstrate that the cell behavior could be controlled onto the polymer and nanocomposite-based surfaces via tuning the surface micro/nano structure.

On the combined use of nanoparticles and a proper solvent/non-solvent system in preparation of superhydrophobic polymer coatings

A novel method including combined use of nanoparticles and non-solvent is proposed for fabrication of superhydrophobic polystyrene coatings. The proposed method results in utterly homogenous and mechanically stable coatings with excellent adhesion to the substrate as compared to the other commonly used solution-based methods. It is proved that individual use of nanoparticles and non-solvent could lead to superhydrophobic behavior but at the price of adding very high contents. Based on water contact angle results, the proposed method causes a significant reduction in the required contents of nanoparticles (150 wt% to 20 wt% with respect to the polymer) and non-solvent (33 vol% to 9–16 vol%) for achieving superhydrophobicity. A thorough investigation of surface composition and morphology is also conducted via X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. Moreover, a different approach is employed for evaluation of surface topography using diverse roughness parameters. It was found that a combination of roughness parameters should be considered for a proper surface analysis instead of only using average roughness and root mean square. It was also demonstrated that the surface roughness uniformity is another key factor to achieve a self-cleaning behavior.

Using gold nanorods labelled with antibodies under the photothermal action of NIR laser radiation on Staphylococcus aureus

The effect of NIR laser radiation and gold nanorods on the cells of two strains of Staphylococcus aureus, one of them being methicillin-sensitive and the other being methicillin-resistant, is studied. Nanorods having the dimensions with the absorption maximum in the NIR spectral region, functionalised with human immunoglobulins IgA and IgG, are synthesised. It is shown that the use of nanoparticles in combination with NIR irradiation leads to killing up to 97 % of the population of microorganisms.

Enhanced delivery of monomethoxypoly(ethylene glycol)‐poly(lactic‐co‐glycolic acid)‐poly l‐lysine nanoparticles loading platelet‐derived growth factor BB small interfering RNA by ultrasound and/or microbubbles to rat retinal pigment epithelium cells

A novel small interfering RNA (siRNA) delivery method based on the combined use of nanoparticles (NPs) with ultrasound (US) and/or microbubbles (MBs) was introduced in the present study. We investigated the efficacy and safety of US and/or MBs-enhanced delivery of monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly l-lysine (mPEG-PLGA-PLL) NPs loading platelet-derived growth factor BB (PDGF-BB) siRNA to rat retinal pigment epithelium (RPE)-J cells. The effect of US and/or MBs on the delivery of NPs containing Cy3-labeled siRNA was evaluated by fluorescence microscopy and flow cytometry. Potential toxicity of NPs and cell viability under different conditions of US and/or MBs were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The results obtained showed that low intensity US or 15-20% MBs could increase the delivery efficiency of a lower concentration of mPEG-PLGA-PLL NPs loading siRNA to RPE-J cells, whereas the combination of US with MBs under the optimal conditions for the enhancement of NPs delivery did not further increase the cellular uptake of NPs compared to either US or MBs alone (p = 0.072 and p = 0.488, respectively). Under the optimal condition for US-enhanced NPs delivery, the enhanced PDGF-BB gene silencing with a combination of US and NPs encapsulating siRNA resulted in a significant decrease of mRNA and protein expression levels compared to NPs alone. US and/or MBs could be used safely to enhance the delivery of NPs loading siRNA to rat RPE-J cells. A combination of the chemical (mPEG-PLGA-PLL NPs loading siRNA) and physical (US) approaches could more effectively downregulate the mRNA and protein expression of PDGF-BB.

Effect of functionalised fluorescence-labelled nanoparticles on mesenchymal stem cell differentiation

The combined use of nanoparticles and mesenchymal stem cells (MSC) in regenerative medicine requires the incorporation of the particles and, at the same time, undisturbed cell viability and maintenance of the multi-lineage potential of MSC. The aim of this study was to investigate the uptake of novel phosphonate-functionalised polystyrene nanoparticles prepared by miniemulsion polymerisation. After exposition of human MSC to the particles, their uptake and localisation were analysed by flow cytometry, confocal laser scanning microscopy (CLSM), and transmission electron microscopy (TEM). The osteogenic, adipogenic and chondrogenic differentiation potential was examined by analysing representative marker genes by RT-PCR. Flow cytometry revealed that after 5 and 16 days more than 98% of the MSC and of the cells, which underwent osteogenic and adipogenic differentiation were positive for particle association. CLSM and TEM demonstrated the successful intracellular incorporation of the particles without using any transfection agents and their presence over the cultivation period. The cell viability was found to be unaffected. Particle treated MSC maintained their potential for osteogenic, adipogenic and chondrogenic differentiation. It was concluded that the surface functionalisation with phosphonate groups provides a promising basis for the development of nanoparticles with high intracellular uptake rates for drug delivery or cell labelling.

Sludge conditioning by using alumina nanoparticles and polyelectrolyte

The combined use of nanoparticle and polyelectrolyte as retention aids in pulp and paper industry tend to give better flocculation (retention) and drainage (dewatering) than conventional polyelectrolyte flocculation. The combined use of alumina nanoparticle and polyelectrolyte in conditioning waste activated sludge was investigated in the current study. Alumina with three different sizes (139.5, 241.7, and 326.4 nm) was utilized in combination with a cationic polyelectrolyte (T3052) of molecular weight of 1.1 x 10(7) and charge density of 2.1 meq/g. It was found from capillary suction time (CST) and specific resistance to filtration (SRF) measurement that sludge conditioned with alumina/polyelectrolyte showed a better dewaterability than polyelectrolyte alone. In addition, it was found that the better dewaterability was obtained as alumina became smaller. Floc size and fractal dimension of flocs were examined as well. The mechanism of enhanced dewaterability was proposed that alumina nanoparticles became adsorbed onto sludge and positive patches were formed. The electrostatic repulsion made the polyelectrolyte more stretched, and resulted in more effective flocculation and bridging as polyelectrolyte was added. Dosing sequence also affected the conditioning effectiveness. However, the combined use of silica nanoparticles and a cationic polelectrolyte, KP-201C, or alumina nanoparticles and an anionic polyelectrolyte, AP410, did not result in improved dewaterability of waste activated sludge. Possible explanation was discussed. Preliminary results show that some in-depth work is needed regarding the introduction of nanoparticles in sludge conditioning.