Bromelain extraction using single stage nanofiltration membrane process.

Pineapple (Ananas Comosus) is a tropical fruit having exceptional juiciness, vibrant tropical flavor and immense health benefits. Pineapples are not only taken fresh but they have been commercialized in the canning industry. Morris cultivar is mostly supplied to the canning industry where only the flesh is utilized and the rest of the pineapple (50 wt%) such as the core, stem, peels and crown are discarded as wastes. In the extraction of bromelain which is a vital proteolytic enzyme the whole pineapple including its peels, core, stem and crown can be utilized. This enzyme is very valuable and considered as a food supplement with a wide range of therapeutic benefits. Thus, in this study, bromelain is extracted from the flesh, crown, stem, core and peel of pineapples using simple one stage hollow fiber nanofiltration membrane process. The different parts of the pineapple were crushed to extract the juice. The juice was then centrifuged and the supernatant was then passed through a nanofiltration membrane. Results revealed the retentates from the different pineapple parts contain high amounts of bromelain in descending order flesh > peel > core > crown > stem. The amount of bromelain activity increased after every process especially after freeze drying.

Development of 3D Thermoplastic Polyurethane (TPU)/Maghemite (ϒ-Fe2O3) Using Ultra-Hard and Tough (UHT) Bio-Resin for Soft Tissue Engineering.

The use of soft tissue engineering scaffolds is an advanced approach to repairing damaged soft tissue. To ensure the success of this technique, proper mechanical and biocompatibility properties must be taken into consideration. In this study, a three-dimensional (3D) scaffold was developed using digital light processing (DLP) and ultra-hard and tough (UHT) bio-resin. The 3D scaffold structure consisted of thermoplastic polyurethane (TPU) and maghemite (ϒ-Fe2O3) nanoparticles mixed with UHT bio-resin. The solution sample for fabricating the scaffolds was varied with the concentration of the TPU (10, 12.5, and 15% wt/v) and the amount of ϒ-Fe2O3 (1, 3, and 5% v/v) added to 15% wt/v of TPU. Before developing the real geometry of the sample, a pre-run of the DLP 3D printing process was done to determine the optimum curing time of the structure to be perfectly cured, which resulted in 30 s of curing time. Then, this study proceeded with a tensile test to determine the mechanical properties of the developed structure in terms of elasticity. It was found that the highest Young's Modulus of the scaffold was obtained with 15% wt/v TPU/UHT with 1% ϒ-Fe2O3. Furthermore, for the biocompatibility study, the degradation rate of the scaffold containing TPU/UHT was found to be higher compared to the TPU/UHT containing ϒ-Fe2O3 particles. However, the MTT assay results revealed that the existence of ϒ-Fe2O3 in the scaffold improved the proliferation rate of the cells.

Effect of Dope Flow Rate and Post-Treatment on the Morphology, Permeation and Metal Ion Rejection from PES/LiBr-Based UF Hollow Fiber Membranes.

This study investigated the influence of dope extrusion rate (DER) and post-treatment effect on the morphology, permeation, and metal ion rejection by polyethersulfone/lithium bromide (PES/LiBr)-based hollow fiber (HF) membranes. HF fibers were spun with 2.25, 2.5, and 3.1 ratios of DER to bore fluid rate (BFR), wherein DER varied from 11.35, 12.5, to 15.6 mL/min with a fixed BFR (5 mL/min). Molecular weight cutoff (MWCO), pore size, water flux, and flux recovery ratio were determined, whereas lake water was used to observe the rejection rate of dissolved metallic ions. Results showed that with the increase of the DER wall thickness (WT), HFs increased from 401.5 to 419.5 um, and furthermore by the post-treatments up to 548.2 um, as confirmed by field emission scanning electron microscope (FESEM) analysis. Moreover, MWCO, pore size, and the pure water permeation (PWP) of the HF membranes decreased, while the separation performance for polyethylene glycol (PEG) solute increased with increasing DER. Post-treated HFs from 11.35 mL/min of DER showed 93.8% of MWCO value with up to 90% and 70% rejection of the arsenic and chromium metallic ions, respectively, in comparison with all other formulated HFs.

Dual Optimized Sulfonated Polyethersulfone and Functionalized Multiwall Carbon Tube Based Composites High Fouling Resistance Membrane for Protein Separation.

Commercial grade sulfonated-Polyethersulfone (S-PES) and functionalized multiwall carbon nanotube (f-MWCNT)/polyvinylpyrrolidone (PVP) nanocomposites (NCs) were used to enhance and optimize the antifouling, protein resistance and protein separation properties of the S-PES ultrafiltration membranes. The polarities of sulfonic groups of S-PES, carbonyl carbon of pyrrolidone, hydroxyl and carboxyl groups of f-MWCNT in the membrane composition helped to strongly bind each other through hydrogen bonding, as shown by Fourier-transform infrared spectroscopy (FTIR). These binding forces greatly reduced the leaching of NCs and developed long finger-like projection, as confirmed by elution ratio and cross-sectional studies of the membranes via field emission scanning electron microscope (FESEM). The contact angle was reduced up to 48% more than pristine PES. Atomic force microscopy (AFM) was employed to study the various parameters of surface roughness with 3d diagrams, while grain analysis of membrane surface provided a quantitative estimation about volume, area, perimeter, length, radius and diameter. The NCs/S-PES enhanced the flux rate with an impressive (80-84%) flux recovery ratio and (58-62%) reversible resistance (Rr) value in situ, with 60% and 54.4% lesser dynamic and static protein adsorption. The best performing membrane were reported to remove 31.8%, 66.3%, 83.6% and 99.9% for lysozyme-(14.6 kDa), trypsin-(20 kDa), pepsin-(34.6 kDa) and bovine serum albumin (BSA-66 kDa), respectively.

Review on Nanocrystalline Cellulose in Bone Tissue Engineering Applications.

Nanocrystalline cellulose is an abundant and inexhaustible organic material on Earth. It can be derived from many lignocellulosic plants and also from agricultural residues. They endowed exceptional physicochemical properties, which have promoted their intensive exploration in biomedical application, especially for tissue engineering scaffolds. Nanocrystalline cellulose has been acknowledged due to its low toxicity and low ecotoxicological risks towards living cells. To explore this field, this review provides an overview of nanocrystalline cellulose in designing materials of bone scaffolds. An introduction to nanocrystalline cellulose and its isolation method of acid hydrolysis are discussed following by the application of nanocrystalline cellulose in bone tissue engineering scaffolds. This review also provides comprehensive knowledge and highlights the contribution of nanocrystalline cellulose in terms of mechanical properties, biocompatibility and biodegradability of bone tissue engineering scaffolds. Lastly, the challenges for future scaffold development using nanocrystalline cellulose are also included.

Papain grafted into the silica coated iron-based magnetic nanoparticles 'IONPs@SiO2-PPN' as a new delivery vehicle to the HeLa cells.

The present study aims at engineering, fabrication, characterization, and qualifications of papain (PPN) conjugated SiO2-coated iron oxide nanoparticles 'IONPs@SiO2-PPN'. Initially fabricated iron oxide nanoparticles (IONPs) were coated with silica (SiO2) using sol-gel method to hinder the aggregation and to enhance biocompatibility. Next, PPN was loaded as an anticancer agent into the silica coated IONPs (IONPs@SiO2) for the delivery of papain to the HeLa cancer cells. This fabricated silica-coated based magnetic nanoparticle is introduced as a new physiologically-compatible and stable drug delivery vehicle for delivering of PPN to the HeLa cancer cell line. The IONPs@SiO2-PPN were characterized using FT-IR, AAS, FESEM, XRD, DLS, and VSM equipment. Silica was amended on the surface of iron oxide nanoparticles (IONPs, γ-Fe2O3) to modify its biocompatibility and stability. The solvent evaporation method was used to activate PPN vectorization. The following tests were performed to highlight the compatibility of our proposed delivery vehicle: in vitro toxicity assay, in vivo acute systemic toxicity test, and the histology examination. The results demonstrated that IONPs@SiO2-PPN successfully reduced the IC50 values compared with the native PPN. Also, the structural alternations of HeLa cells exposed to IONPs@SiO2-PPN exhibited higher typical hallmarks of apoptosis compared to the cells treated with the native PPN. The in vivo acute toxicity test indicated no clinical signs of distress/discomfort or weight loss in Balb/C mice a week after the intravenous injection of IONPs@SiO2 (10 mg kg-1). Besides, the tissues architectures were not affected and the pathological inflammatory alternations detection failed. In conclusion, IONPs@SiO2-PPN can be chosen as a potent candidate for further medical applications in the future, for instance as a drug delivery vehicle or hyperthermia agent.

Hemodialysis performance and anticoagulant activities of PVP-k25 and carboxylic-multiwall nanotube composite blended Polyethersulfone membrane.

Non-covalent electrostatic interaction between amide nitrogen and carbonyl carbon of shorter chain length of polyvinylpyrrolidone (PVP-k25) was developed with in-house carboxylic oxidized multiwall carbon nanotubes (O-MWCNT) and then blended with Polyethersulfone (PES) polymer. FTIR analysis was utilized to confirm bonding nature of nano-composites (NCs) of O-MWCNT/PVP-k25 and casting membranes. Non-solvent induces phase separation process developed regular finger-like channels in composite membranes whereas pristine PES exhibited spongy entities as studied by cross sectional analysis report of FESEM. Further, FESEM instrument was also utilized to observe the dispersion of O-MWCNT/PVP based nanocomposite (NCs) with PES and membranes leaching phenomena analysis. Contact angle experiments described 24% improvement of hydrophilic behaviour, leaching ratio of additives was reduced to 1.89%, whereas water flux enhanced up to 6 times. Bovine serum albumin (BSA) and lysozyme based antifouling analysis shown up to 25% improvement, whereas 84% of water flux was regained after protein fouling than pristine PES. Anticoagulant activity was reported by estimating prothrombin, thrombin, plasma re-calcification times and production of fibrinogen cluster with platelets-adhesions photographs and hemolysis experiments. Composite membranes exhibited 3.4 and 3 times better dialysis clearance ratios of urea and creatinine solutes as compared to the raw PES membrane.

Fabrication and performance evaluation of blood compatible hemodialysis membrane using carboxylic multiwall carbon nanotubes and low molecular weight polyvinylpyrrolidone based nanocomposites.

This study focused to optimize the performance of polyethersulfone (PES) hemodialysis (HD) membrane using carboxylic functionalized multiwall carbon nanotubes (c-MWCNT) and lower molecular weight grade of polyvinylpyrrolidone (PVP-k30). Initially, MWCNT were chemically functionalized by acid treatment and nanocomposites (NCs) of PVP-k30 and c-MWCNT were formed and subsequently blended with PES polymer. The spectra of FTIR of the HD membranes revealed that NCs has strong hydrogen bonding and their addition to PES polymer improved the capillary system of membranes as confirmed by Field Emission Scanning Electron Microscope (FESEM) and leaching of the additive decreased to 2% and hydrophilicity improved to 22%. The pore size and porosity of NCs were also enhanced and rejection rate was achieved in the establish dialysis range (<60 kDa). The antifouling studies had shown that NCs membrane exhibited 30% less adhesion of protein with 80% flux recovery ratio. The blood compatibility assessment disclosed that NCs based membranes showed prolonged thrombin and prothrombin clotting times, lessened production of fibrinogen cluster, and greatly suppressed adhesion of blood plasma than a pristine PES membrane. The results also unveiled that PVP-k30/NCs improved the surface properties of the membrane and the urea and creatinine removal increased to 72% and 75% than pure PES membranes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 513-525, 2019.

Kinetics, thermodynamics, equilibrium isotherms, and reusability studies of cationic dye adsorption by magnetic alginate/oxidized multiwalled carbon nanotubes composites.

Magnetic beads (AO-γ-Fe2O3) of alginate (A) impregnated with citrate coated maghemite nanoparticles (γ-Fe2O3) and oxidized multiwalled carbon nanotubes (OMWCNTs) were synthesized and used as adsorbent for the removal of methylene blue from water. The XRD analysis revealed that the diameter of γ-Fe2O3 is 10.24 nm. The mass saturation magnetization of AO-γ-Fe2O3 and γ-Fe2O3 were found to be 27.16 and 42.63 emu·g-1, respectively. The adsorption studies revealed that the data of MB isotherm were well fitted to the Freundlich model. The Langmuir isotherm model exhibited a maximum adsorption capacity of 905.5 mg·g-1. The adsorption was very dependent on initial concentration, adsorbent dose, and temperature. The beads exhibited high adsorption stability in large domain of pH (4-10). The thermodynamic parameters determined at 283, 293, 303, and 313 K revealed that the adsorption occurring was spontaneous and endothermic in nature. Adsorption kinetic data followed the intraparticle diffusion model. The AO-γ-Fe2O3 beads were used for six cycles without significant adsorptive performance loss. Therefore, the eco-friendly prepared AO-γ-Fe2O3 beads were considered as highly recyclable and efficient adsorbent for methylene blue as they can be easily separated from water after treatment.

Novel Processing Technique to Produce Three Dimensional Polyvinyl Alcohol/Maghemite Nanofiber Scaffold Suitable for Hard Tissues.

Fabrication of three dimensional (3D) tissue engineering scaffolds, particularly for hard tissues remains a challenge. Electrospinning has been used to fabricate scaffolds made from polymeric materials which are suitable for hard tissues. The electrospun scaffolds also have structural arrangement that mimics the natural extracellular matrix. However, electrospinning has a limitation in terms of scaffold layer thickness that it can fabricate. Combining electrospinning with other processes is the way forward, and in this proposed technique, the basic shape of the scaffold is obtained by a fused deposition modelling (FDM) three dimensional (3D) printing machine using the partially hydrolysed polyvinyl alcohol (PVA) as the filament material. The 3D printed PVA becomes a template to be placed inside a mould which is then filled with the fully hydrolysed PVA/maghemite (γ-Fe2O3) solution. After the content in the mould solidified, the mould is opened and the content is freeze dried and immersed in water to dissolve the template. The 3D structure made of PVA/maghemite is then layered by electrospun PVA/maghemite fibers, resulting in 3D tissue engineering scaffold made from PVA/maghemite. The morphology and mechanical properties (strength and stiffness) were analysed and in vitro tests by degradation test and cell penetration were also performed. It was revealed that internally, the 3D scaffold has milli- and microporous structures whilst externally; it has a nanoporous structure as a result of the electrospun layer. The 3D scaffold has a compressive strength of 78.7 ± 0.6 MPa and a Young's modulus of 1.43 ± 0.82 GPa, which are within the expected range for hard tissue engineering scaffolds. Initial biocompatibility tests on cell penetration revealed that the scaffold can support growth of human fibroblast cells. Overall, the proposed processing technique which combines 3D printing process, thermal inversion phase separation (TIPS) method and electrospinning process has the potential for producing hard tissue engineering 3D scaffolds.

Optimization and development of Maghemite (γ-Fe2O3) filled poly-l-lactic acid (PLLA)/thermoplastic polyurethane (TPU) electrospun nanofibers using Taguchi orthogonal array for tissue engineering heart valve.

Tissue engineering (TE) is an advanced principle to develop a neotissue that can resemble the original tissue characteristics with the capacity to grow, to repair and to remodel in vivo. This research proposed the optimization and development of nanofiber based scaffold using the new mixture of maghemite (γ-Fe2O3) filled poly-l-lactic acid (PLLA)/thermoplastic polyurethane (TPU) for tissue engineering heart valve (TEHV). The chemical, structural, biological and mechanical properties of nanofiber based scaffold were characterized in terms of morphology, porosity, biocompatibility and mechanical behaviour. Two-level Taguchi experimental design (L8) was performed to optimize the electrospun mats in terms of elastic modulus using uniaxial tensile test where the studied parameters were flow rate, voltage, percentage of maghemite nanoparticles in the content, solution concentration and collector rotating speed. Each run was extended with an outer array to consider the noise factors. The signal-to-noise ratio analysis indicated the contribution percent as follow; Solution concentration>voltage>maghemite %>rotating speed>flow rate. The optimum elastic modulus founded to be 28.13±0.37MPa in such a way that the tensile strain was 31.72% which provided desirability for TEHV. An empirical model was extracted and verified using confirmation test. Furthermore, an ultrafine quality of electrospun nanofibers with 80.32% porosity was fabricated. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and cell attachment using human aortic smooth muscle cells exhibited desirable migration and proliferation over the electrospun mats. The interaction between blood content and the electrospun mats indicated a mutual adaption in terms of clotting time and hemolysis percent. Overall, the fabricated scaffold has the potential to provide the required properties of aortic heart valve.

A review of evolution of electrospun tissue engineering scaffold: From two dimensions to three dimensions.

The potential of electrospinning process to fabricate ultrafine fibers as building blocks for tissue engineering scaffolds is well recognized. The scaffold construct produced by electrospinning process depends on the quality of the fibers. In electrospinning, material selection and parameter setting are among many factors that contribute to the quality of the ultrafine fibers, which eventually determine the performance of the tissue engineering scaffolds. The major challenge of conventional electrospun scaffolds is the nature of electrospinning process which can only produce two-dimensional electrospun mats, hence limiting their applications. Researchers have started to focus on overcoming this limitation by combining electrospinning with other techniques to fabricate three-dimensional scaffold constructs. This article reviews various polymeric materials and their composites/blends that have been successfully electrospun for tissue engineering scaffolds, their mechanical properties, and the various parameters settings that influence the fiber morphology. This review also highlights the secondary processes to electrospinning that have been used to develop three-dimensional tissue engineering scaffolds as well as the steps undertaken to overcome electrospinning limitations.

3D Biofabrication of Thermoplastic Polyurethane (TPU)/Poly-l-lactic Acid (PLLA) Electrospun Nanofibers Containing Maghemite (γ-Fe2O3) for Tissue Engineering Aortic Heart Valve.

Valvular dysfunction as the prominent reason of heart failure may causes morbidity and mortality around the world. The inability of human body to regenerate the defected heart valves necessitates the development of the artificial prosthesis to be replaced. Besides, the lack of capacity to grow, repair or remodel of an artificial valves and biological difficulty such as infection or inflammation make the development of tissue engineering heart valve (TEHV) concept. This research presented the use of compound of poly-l-lactic acid (PLLA), thermoplastic polyurethane (TPU) and maghemite nanoparticle (γ-Fe2O3) as the potential biomaterials to develop three-dimensional (3D) aortic heart valve scaffold. Electrospinning was used for fabricating the 3D scaffold. The steepest ascent followed by the response surface methodology was used to optimize the electrospinning parameters involved in terms of elastic modulus. The structural and porosity properties of fabricated scaffold were characterized using FE-SEM and liquid displacement technique, respectively. The 3D scaffold was then seeded with aortic smooth muscle cells (AOSMCs) and biological behavior in terms of cell attachment and proliferation during 34 days of incubation was characterized using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and confocal laser microscopy. Furthermore, the mechanical properties in terms of elastic modulus and stiffness were investigated after cell seeding through macro-indentation test. The analysis indicated the formation of ultrafine quality of nanofibers with diameter distribution of 178 ± 45 nm and 90.72% porosity. In terms of cell proliferation, the results exhibited desirable proliferation (109.32 ± 3.22% compared to the control) of cells over the 3D scaffold in 34 days of incubation. The elastic modulus and stiffness index after cell seeding were founded to be 22.78 ± 2.12 MPa and 1490.9 ± 12 Nmm², respectively. Overall, the fabricated 3D scaffold exhibits desirable structural, biological and mechanical properties and has the potential to be used in vivo.

Trastuzumab-decorated nanoparticles for in vitro and in vivo tumor-targeting hyperthermia of HER2+ breast cancer.

In this study, a magnetic core-shell modified tumor-targeting nanocarrier (MNPs-PEG-TRA) was engineered and demonstrated for the efficient in vitro and in vivo hyperthermia treatment of breast cancer. Magnetic nanoparticles were used as the initial nanocarriers and modified via PEGylation followed by immobilization of Trastuzumab (TRA) with tumor-targeting function towards cancer cells. The hyperthermia performance of the developed targeting drug delivery system was explored using an in vitro study with SK-BR-3 cancer cells and an in vivo study using animal models (mouse) with DMBA-induced breast cancer. The average size of the engineered system was about 100 nm and its zeta potential was about +13 mV, whereby the stability of the system in biological media is enormously enhanced while the possibility of it being removed via the immune system is diminished. The investigation was pursued based on comparing the changes in growth inhibition rates of HSF 1184, MDA-MB-231, MDA-MB-468 and SK-BR-3 cell lines at different temperatures (37 °C, 40 °C, 42 °C, and 45 °C). Compared with bare MNPs and MNPs-PEG, a remarkably enhanced hyperthermia effect using MNPs-PEG-TRA was observed not only in cultured SK-BR-3 cells in vitro but also in an in vivo DMBA tumor bearing mice model. These results are attributed to an about 4 fold higher concentration of MNPs-PEG-TRA carriers in the tumor site compared to the other organs confirming the considerable potential of the magnetic tumor-targeting hyperthermia concept for breast cancer treatment.

Development of highly porous biodegradable γ-Fe2O3/polyvinyl alcohol nanofiber mats using electrospinning process for biomedical application.

The use of electrospinning process in fabricating tissue engineering scaffolds has received great attention in recent years due to its simplicity. The nanofibers produced via electrospinning possessed morphological characteristics similar to extracellular matrix of most tissue components. Porosity plays a vital role in developing tissue engineering scaffolds because it influences the biocompatibility performance of the scaffolds. In this study, maghemite (γ-Fe2O3) was mixed with polyvinyl alcohol (PVA) and subsequently electrospun to produce nanofibers. Five factors; nanoparticles content, voltage, flow rate, spinning distance, and rotating speed were varied to produce the electrospun nanofibrous mats with high porosity value. Empirical model was developed using response surface methodology to analyze the effect of these factors to the porosity. The results revealed that the optimum porosity (90.85%) was obtained using 5% w/v nanoparticle content, 35kV of voltage, 1.1ml/h volume flow rate of solution, 8cm spinning distance and 2455rpm of rotating speed. The empirical model was verified successfully by performing confirmation experiments. The properties of optimum PVA/γ-Fe2O3 nanofiber mats such as fiber diameter, mechanical properties, and contact angle were investigated. In addition, cytocompatibility test, in vitro degradation rate, and MTT assay were also performed. Results revealed that high porosity biodegradable γ-Fe2O3/polyvinyl alcohol nanofiber mats have low mechanical properties but good degradation rates and cytocompatibility properties. Thus, they are suitable for low load bearing biomedical application or soft tissue engineering scaffold.

In vitro evaluation of actively targetable superparamagnetic nanoparticles to the folate receptor positive cancer cells.

Engineering of a physiologically compatible, stable and targetable SPIONs-CA-FA formulation was reported. Initially fabricated superparamagnetic iron oxide nanoparticles (SPIONs) were coated with citric acid (CA) to hamper agglomeration as well as to ameliorate biocompatibility. Folic acid (FA) as a targeting agent was then conjugated to the citric acid coated SPIONs (SPIONs-CA) for targeting the specific receptors expressed on the FAR+ cancer cells. Physiochemical characterizations were then performed to assure required properties like stability, size, phase purity, surface morphology, chemical integrity and magnetic properties. In vitro evaluations (MTT assay) were performed on HeLa, HSF 1184, MDA-MB-468 and MDA-MB-231cell lines to ensure the biocompatibility of SPIONs-CA-FA. There were no morphological changes and lysis in contact with erythrocytes recorded for SPIONs-CA-FA and SPIONs-CA. High level of SPIONs-CA-FA binding to FAR+ cell lines was assured via qualitative and quantitative in vitro binding studies. Hence, SPIONs-CA-FA was introduced as a promising tool for biomedical applications like magnetic hyperthermia and drug delivery. The in vitro findings presented in this study need to be compared with those of in vivo studies.

Mechanical properties and biocompatibility of co-axially electrospun polyvinyl alcohol/maghemite.

Electrospinning is a simple and efficient process in producing nanofibers. To fabricate nanofibers made of a blend of two constituent materials, co-axial electrospinning method is an option. In this method, the constituent materials contained in separate barrels are simultaneously injected using two syringe nozzles arranged co-axially and the materials mix during the spraying process forming core and shell of the nanofibers. In this study, co-axial electrospinning method is used to fabricate nanofibers made of polyvinyl alcohol and maghemite (γ-Fe2O3). The concentration of polyvinyl alcohol and amount of maghemite nanoparticle loading were varied, at 5 and 10 w/v% and at 1-10 v/v%, respectively. The mechanical properties (strength and Young's modulus), porosity, and biocompatibility properties (contact angle and cell viability) of the electrospun mats were evaluated, with the same mats fabricated by regular single-nozzle electrospinning method as the control. The co-axial electrospinning method is able to fabricate the expected polyvinyl alcohol/maghemite nanofiber mats. It was noticed that the polyvinyl alcohol/maghemite electrospun mats have lower mechanical properties (i.e. strength and stiffness) and porosity, more hydrophilicity (i.e. lower contact angle), and similar cell viability compared to the mats fabricated by single-nozzle electrospinning method.

Ionic liquid as a promising biobased green solvent in combination with microwave irradiation for direct biodiesel production.

The wet biomass microalgae of Nannochloropsis sp. was converted to biodiesel using direct transesterification (DT) by microwave technique and ionic liquid (IL) as the green solvent. Three different ionic liquids; 1-butyl-3-metyhlimidazolium chloride ([BMIM][Cl], 1-ethyl-3-methylimmidazolium methyl sulphate [EMIM][MeSO4] and 1-butyl-3-methylimidazolium trifluoromethane sulfonate [BMIM][CF3SO3]) and organic solvents (hexane and methanol) were used as co-solvents under microwave irradiation and their performances in terms of percentage disruption, cell walls ruptured and biodiesel yields were compared at different reaction times (5, 10 and 15 min). [EMIM][MeSO4] showed highest percentage cell disruption (99.73%) and biodiesel yield (36.79% per dried biomass) after 15 min of simultaneous reaction. The results demonstrated that simultaneous extraction-transesterification using ILs and microwave irradiation is a potential alternative method for biodiesel production.

Synthesis, characterization and in vitro evaluation of exquisite targeting SPIONs-PEG-HER in HER2+ human breast cancer cells.

A stable, biocompatible and exquisite SPIONs-PEG-HER targeting complex was developed. Initially synthesized superparamagnetic iron oxide nanoparticles (SPIONs) were silanized using 3-aminopropyltrimethoxysilane (APS) as the coupling agent in order to allow the covalent bonding of polyethylene glycol (PEG) to the SPIONs to improve the biocompatibility of the SPIONs. SPIONs-PEG were then conjugated with herceptin (HER) to permit the SPIONs-PEG-HER to target the specific receptors expressed over the surface of the HER2+ metastatic breast cancer cells. Each preparation step was physico-chemically analyzed and characterized by a number of analytical methods including AAS, FTIR spectroscopy, XRD, FESEM, TEM, DLS and VSM. The biocompatibility of SPIONs-PEG-HER was evaluated in vitro on HSF-1184 (human skin fibroblast cells), SK-BR-3 (human breast cancer cells, HER+), MDA-MB-231 (human breast cancer cells, HER-) and MDA-MB-468 (human breast cancer cells, HER-) cell lines by performing MTT and trypan blue assays. The hemolysis analysis results of the SPIONs-PEG-HER and SPIONs-PEG did not indicate any sign of lysis while in contact with erythrocytes. Additionally, there were no morphological changes seen in RBCs after incubation with SPIONs-PEG-HER and SPIONs-PEG under a light microscope. The qualitative and quantitative in vitro targeting studies confirmed the high level of SPION-PEG-HER binding to SK-BR-3 (HER2+ metastatic breast cancer cells). Thus, the results reflected that the SPIONs-PEG-HER can be chosen as a favorable biomaterial for biomedical applications, chiefly magnetic hyperthermia, in the future.

Efficiency of barium removal from radioactive waste water using the combination of maghemite and titania nanoparticles in PVA and alginate beads.

In this paper, both maghemite (γ-Fe2O3) and titanium oxide (TiO2) nanoparticles were synthesized and mixed in various ratios and embedded in PVA and alginate beads. Batch sorption experiments were applied for removal of barium ions from aqueous solution under sunlight using the beads. The process has been investigated as a function of pH, contact time, temperature, initial barium ion concentration and TiO2:γ-Fe2O3 ratios (1:10, 1:60 and 1). The recycling attributes of these beads were also considered. Furthermore, the results revealed that 99% of the Ba(II) was eliminated in 150min at pH 8 under sunlight. Also, the maghemite and titania PVA-alginate beads can be readily isolated from the aqueous solution after the process and reused for at least 7 times without significant losses of their initial properties. The reduction of Ba(II) with maghemite and titania PVA-alginate beads fitted the pseudo first order and second order Langmuir-Hinshelwood (L-H) kinetic model.