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In recent years, shape memory polyurethanes have gained substantial attention and are targeted for a range of smart and functional materials. In this work, the development of nanocrystalline celluloses (CNCs) enabled polycaprolactone-based shape memory polyurethane biocomposite using an in situ one-pot reactions is reported. The incorporation of up to 10 wt. % CNCs resulted in a remarkable enhancement in the tensile strength at yield (from 0.2 MPa to 7.2 MPa), tensile strength at break (167% improvement), and modulus of elasticity (from 3.5 to 139.3 MPa) while maintaining the elongation at break. This was attributed to the simultaneous action of CNCs as a nucleating agent for crystallization and highly compatibilized reinforcing agent of the network. Moreover, the in situ incorporation of CNCs enhanced the shape memory capability of polyurethanes, which enables its employment in functional material applications, such as the biomedical sector. The intimate interfacial adhesion between the CNCs and the polymer matrix, which promoted shape fixating and recovery, was confirmed by fractured surface morphology studies. Rheology characterizations provided strong evidence that the addition of CNCs increased the shape fixity attributed to the stiffness of CNCs below the glass transition temperature (Tg) compared to the neat PU in conjuncture with the higher Tg of CNCs. Overall, the developed polymer nanocomposites are appealing materials for biomedical applications.

Ending the fossil fuel era towards a sustainable future will require high-performing renewable materials with a low environmental impact. Carbon black, produced by partial combustion or thermal decomposition of petroleum hydrocarbons, is by far the most dominant filler of rubber composites, followed by mineral fillers (e.g. silica, talc, clay, calcium carbonate, etc.). However, the manufacture of carbon black has a considerable carbon footprint. Similarly, mineral fillers also do not come without challenges, including poor compatibility with rubber matrices and high density. Consequently, the need for sustainable and green fillers with a low or even zero carbon footprint has dramatically increased. In recent years, plant-derived sustainable materials, such as cellulose nanocrystals, natural fibers, lignin, biochar, polysaccharides, etc., have been extensively investigated as substitute or complementary fillers of rubbers. In this work, we critically reviewed recent developments in the innovation and utilization of sustainable biofillers for rubber composite applications, emphasizing the effect of the filler on the structure–processing–property relationships in rubber composites. A wide range of biofillers with an array of structure, morphology, and physico-chemical properties and their various attributes in different rubbers are intensively reviewed and discussed. Effective preparation strategies and surface modification platforms on the different biofillers to develop high-performance sustainable rubber biocomposites were critically reviewed. Finally, future perspectives for biofillers in rubber composite applications and challenges are discussed.

The advent of the COVID-19 pandemic has generated an increased consumption of personal protective equipment (PPE), including gloves and masks, by healthcare workers and by the general public at a g...

Cellulose nanocrystals (CNCs) have been modified through surface graft polymerization of (l)-lactide for the purpose of improving dispersion and reducing aggregation of CNCs into chloroprene rubber (CR). Statistically designed experiments have been carried out to study the effects of polymerization conditions (temperature, and catalyst and monomer concentrations) on water contact angle, solvent dispersibility, and particle size distribution of the produced mCNCs. The effects of catalyst concentration and interaction of monomer-catalyst concentrations were found to be significant. Dry films produced from mCNCs exhibited surface hydrophobicity as evidenced by very high water contact angles (> 90°). In addition, mCNCs in powder form exhibited very good water/latex dispersibility. Blending of mCNCs with CR latex resulted in well-dispersed modified CNC/CR composites based on microscopy observations. The tensile properties of cast films produced from CNC/CR and mCNC/CR composites have been evaluated and it has been found that increasing the CNC and mCNC content increases tensile strength and modulus while maintaining elongation at break close to that of the unfilled CR. Composites containing 3 wt% of mCNCs exhibited the best properties with tensile strength and modulus improving by about 200% and 450%, respectively. These results are very promising and suggest that these mCNC/CR composites could find applications in the manufacturing of cut/fat resistant medical gloves, balloons, catheters, and other biomedical devices.

Cellulose nanocrystals (CNCs), a robust renewable and green nanomaterial, has potential as an excellent reinforcing and multifunctional filler for polymers used in coating and other applications. However, the high polarity of CNCs limits its interfacial interaction and dispersibility with several non-polar polymers. These limitations severely constrain it from transferring its functional attributes to polymeric materials. In this paper, three differentiated cationic surfactants: cetyltetramethylammoniumbromide (CTAB, C16 single chain), dimethyldidodecylammonium bromide (DDAB, C12 double chains) and dimethyldihexadecylammonium (DHAB, C16 double chains) were used to modify the surface of CNCs. The modifications were confirmed using Fourier-Transform Infrared Spectroscopy (FTIR) and elemental analysis. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) of the samples revealed that the crystallinities and the thermal stabilities of the modified CNCs were preserved. Corrosion protection studies of epoxy nanocomposites containing the native and surfactant modified CNCs were conducted using model steel specimens via salt spray and electrochemical test methods. The results reported herein indicated that the use of surfactant modified CNCs resulted in an enhanced dispersibility in the epoxy matrices as compared to native CNCs. The improved dispersion assisted in retardation of the penetration of electrolyte that caused a remarkable improvement in the metal corrosion protection performance, as compared to unfilled or native CNC filled epoxy coatings.

Doping of non-linear optical materials by different elements and compounds is the common method to tune the various properties of these materials. In this work we report single crystals of undoped and lanthanum chloride (LaCl3) doped L-Alanine Maleate (LAM) grown by slow evaporation solution growth method at room temperature. From the single crystal X-ray diffraction analysis it was observed that both undoped, 1 and 2 mol% LaCl3-doped LAM samples were crystallized in the orthorhombic crystal system with P212121 space group. The optical properties of the LAM single crystals investigated by UV–VIS/NIR spectrometer revealed that the crystals were transparent in the wavelength range of 300–1100 nm. The band gap of the undoped and LaCl3 doped LAM single crystals were found to be 4.13 eV. Energy dispersive X-ray analysis confirmed the incorporation of LaCl3 in LAM single crystals. Simultaneous TG/DT analysis revealed the thermal stability of the samples below 145 °C. The second harmonic generation efficiency of the samples was analyzed by Kurtz-Perry powder technique and compared with the standard KDP crystal.

Natural rubber (NR) foams reinforced by a physical hybrid of nanographene/carbon nanotubes were fabricated using a two-roll mill and compression molding process. The effects of nanographene (GNS) and carbon nanotubes (CNT) were investigated on the curing behavior, foam morphology, and mechanical and thermal properties of the NR nanocomposite foams. Microscope investigations showed that the GNS/CNT hybrid fillers acted as nucleation agents and increased the cell density and decreased the cell size and wall thickness. Simultaneously, the cell size distribution became narrower, containing more uniform multiple closed-cell pores. The rheometric results showed that the GNS/CNT hybrids accelerated the curing process and decreased the scorch time from 6.81 to 5.08 min and the curing time from 14.3 to 11.12 min. Other results showed that the GNS/CNT hybrid improved the foam’s curing behavior. The degradation temperature of the nanocomposites at 5 wt.% and 50 wt.% weight loss increased from 407 °C to 414 °C and from 339 °C to 346 °C, respectively, and the residual ash increased from 5.7 wt.% to 12.23 wt.% with increasing hybrid nanofiller content. As the amount of the GNS/CNT hybrids increased in the rubber matrix, the modulus also increased, and the Tg increased slightly from −45.77 °C to −38.69 °C. The mechanical properties of the NR nanocomposite foams, including the hardness, resilience, and compression, were also improved by incorporating GNS/CNT hybrid fillers. Overall, the incorporation of the nano hybrid fillers elevated the desirable properties of the rubber foam.

In this work, enzymatic polymerization derived microcrystalline glucan (MCG) polysaccharides fillers were employed as novel sustainable fillers of natural rubber (NR) films. MCG has a designed platelet morphology, with high crystallinity and colloidal stability in aqueous media and rubber lattices. NR films composed of 0–10 phr MCG were then fabricated using dipping and casting processes. The incorporation of MCG in the NR led to a remarkable enhancement in the tear strength, tensile properties, toughness, and an increase in water vapor permeability but a decrease in ethanol permeation. This behavior is appealing in gloves, where high sweat permeation from hands to the environment and limited to no solvent penetration from the environment to the skin is desired. The study indicated that the enzymatically polymerized MCG are effective reinforcing fillers for NR latex and potentially other elastomers offering the potential for appealing physical property improvements.

Poly(vinyl alcohol) (PVA) is a water-soluble polymer and forms a hydrogel that has been studied as a potential small-diameter (

Non-isothermal thermogravimetric analysis (TGA) was employed to investigate the degradation of polypropylene (PP) during simulated product manufacturing in a secondary process and wood&ndash, plastic composites. Multiple batch mixing cycles were carried out to mimic the actual recycling. Kissinger&ndash, Akahira&ndash, Sunose (KAS), Ozawa&ndash, Flynn&ndash, Wall (OFW), Friedman, Kissinger and Augis models were employed to calculate the apparent activation energy (Ea). Experimental investigation using TGA indicated that the thermograms of PP recyclates shifted to lower temperatures, revealing the presence of an accelerated degradation process induced by the formation of radicals during chain scission. Reprocessing for five cycles led to roughly a 35% reduction in ultimate mixing torque, and a more than 400% increase in the melt flow rate of PP. Ea increased with the extent of degradation (&alpha, ), and the dependency intensified with the reprocessing cycles. In biocomposites, despite the detectable degradation steps of wood and PP in thermal degradation, a partial coincidence of degradation was observed under air. Deconvolution was employed to separate the overlapped cellulose and PP peaks. Under nitrogen, OFW estimations for the deconvoluted PP exposed an upward shift of Ea at the whole range of &alpha, due to the high thermal absorbance of the wood chars. Under air, the Ea of deconvoluted PP showed an irregular rise in the initial steps, which could be related to the high volume of evolved volatiles from the wood reducing the oxygen diffusion.

Biotin receptors are overexpressed by various types of solid cancer cells and play a significant role in tumor metabolism, growth, and metastasis. Thus, targeting the biotin receptors on tumor cells may enhance the efficiency and reduce the side-effects of chemotherapy. The aim of this study was to develop a biotin-coupled poly(amido)amine (PAMAM) (PG4.5) dendrimer nanoparticle to enhance the tumor-specific delivery and intracellular uptake of anticancer drugs via receptor-mediated endocytosis. We modified PG4.5 with diethylenetriamine (DETA) followed by biotin via an amide bond and characterized the resulting PG4.5-DETA-biotin nanoparticles by 1H NMR, FTIR, and Raman spectroscopy. Loading and releasing of gemcitabine (GEM) from PG4.5-DETA-biotin were evaluated by UV&ndash, Visible spectrophotometry. Cell viability and cellular uptake were examined by MTT assay and flow cytometry to assess the biocompatibility, cellular internalization efficiency and antiproliferative activity of PG4.5-DETA-biotin/GEM. Gemcitabine-loaded PG4.5-DETA-biotin nanoparticles were spherical with a particle size of 81.6 &plusmn, 6.08 nm and zeta potential of 0.47 &plusmn, 1.25 mV. Maximum drug-loading content and encapsulation efficiency were 10.84 &plusmn, 0.16% and 47.01 &plusmn, 0.71%, respectively. Nearly 60.54 &plusmn, 1.99% and 73.96 &plusmn, 1.14% of gemcitabine was released from PG4.5-DETA-biotin/GEM nanoparticles after 48 h at the acidic pH values of 6.5 and 5, respectively. Flow cytometry and fluorescence microscopy of cellular uptake results revealed PG4.5-DETA-biotin/GEM nanoparticles selectively targeted cancer cells in vitro. Cytotoxicity assays demonstrated gemcitabine-loaded PG4.5-DETA-biotin significantly reduced cell viability and induced apoptosis in HeLa cells. Thus, biotin-coupled PG4.5-DETA nanocarrier could provide an effective, targeted drug delivery system and selectively convey gemcitabine into tumor cells.

Graphical abstract, Highlights • C. citrates essential oil contains about 71.297 % citral. • 10 % ointment formulation of C. citratus oils did not cause skin irritation. • Oral LD50 of C. citratus essential oil was greater than 2000 mg/kg. • C. citratus essential oil didn’t produce any toxicity sign. • No histopathological changes were detected in the organs tested., Cymbopogon citratus has been used by the local people in Ankober district, northern Ethiopia, as traditional medicine to treat various ailments. Its essential oil has been shown to have antibacterial, antifungal, antiprotozoal, anti-carcinogenic, anti-inflammatory and antioxidant activities amongst others. This study was conducted to determine skin irritation, acute and subacute toxicity of C. citratus essential oil in mice and rabbits. The essential oil was analyzed using GC–MS. The essential oil at dose of 2000 mg/kg body weight was administered to mice for 21 consecutive days. The mice mortality, behavioral change, injury and other signs of illness were recorded once daily. Biochemical parameters were evaluated. Liver and kidney were taken after sacrifice for gross findings and histological analyses. 10 % ointment formulation of C. citratus oils was applied on the rabbit skin to determine skin irritation effects. The result revealed, the presence of citral (71.297%), myrcene (19.034%), 4, 5-epoxycarene (2.780%), linalool (1.713%), ((S)-cis-verbenol (1.110 %), linalool (1.713 %), ((S)-cis-verbenol (1.110 %) and undecan-2-one (1.001 %) in the C. citratus essential oil. There was no significant difference (p > 0.05) in the body weights, gross abnormalities of the organs and biochemical parameters compared to the control. No histopathological changes were detected in the organs tested. 10 % ointment formulation of C. citratus oils did not cause skin irritation. Analysis of results leads to the conclusion that Ethiopian C. citratus essential oil may be considered as relatively safe and non-toxic.

There is a dire need to cut post-harvest food loss to improve global food security, public health, and sustainable natural resource use. Fruits and vegetables constitute one of the most perishable food items and typically require cold storage systems, adequate packaging, and efficient transport and road systems to reduce their loss. This research showed that by stabilizing cornstarch and beeswax emulsion with cellulose nanocrystals, a sustainable and edible coating that substantially reduces the spoilage of fruits and other produce could be obtained. Native and aliphatic succinic anhydride-modified CNCs were employed as Pickering emulsifiers. The effect of emulsion stabilizers concentrations on the enhancement of physical properties, reduction of water vapor loss, and oxygen permeability was investigated, and 2 wt.% modified CNC was selected as the optimal Pickering emulsion stabilizer. Fresh bananas, strawberries, and fresh-cut apples that were dip-coated with the formulated edible coating displayed magnificent color and freshness preservation by reducing oxygen activities and preventing moisture losses. Overall, the studied emulsion is edible and inexpensive, making it an exciting material that can be used to combat fresh produce waste caused by oxidative and enzymatic over-ripening.

Ternary cadmium zinc sulfide (Cd1−xZnxS) thin films were deposited by chemical bath deposition method for the entire range of 0 ≤ x ≤ 1 from acidic chemical bath using tartaric acid and hydrazine as a complexing agents. The X-ray diffraction (XRD) studies revealed that the deposited thin films had hexagonal crystal structure in the range of 0 ≤ x ≤ 0.6 and pure cubic phase at x = 1, whereas, the thin films deposited in the range of 0.72 ≤ x ≤ 0.9 had a mixed cubic and hexagonal structures. Furthermore, the XRD results showed that the crystalline size and lattice constants were decreased linearly with the gradual incorporations of zinc ion in the Cd1−xZnxS thin films. The optical spectroscopy investigation established that the band gap of the deposited ternary thin films found in the range of 3.84 eV to 3.94 eV. The scanning electron microscope studies illustrated that the surface morphologies of the prepared thin films were formed from spherical grains. The presence of cadmium, sulfur and Zinc elements in the synthesized thin films were confirmed by the energy dispersive x-ray analyses. The unusual large band gap obtained for pure cadmium sulfide and ternary Cd1−xZnxS thin films deposited under the present deposition condition together with the preferred orientation along the (002) plane make these thin films useful as a buffer layer in thin film solar cells.

This study has investigated ultrasound-assisted xylitol production through fermentation of dilute acid (pentose-rich) hydrolysate of sugarcane bagasse using free cells of Candida tropicalis. Sonication of fermentation mixture at optimum conditions was carried out in ultrasound bath (37 kHz and 10% duty cycle). Time profiles of substrate and product in control (mechanical shaking) and test (mechanical shaking + sonication) fermentations were fitted to kinetic model using Genetic Algorithm (GA) optimization. Max. xylitol yield of 0.56 g/g and 0.61 g/g of xylose was achieved in control and test fermentations, respectively. The biomass yield also increased marginally (∼17%) with sonication. However, kinetics of fermentation increased drastically (2.5×) with sonication with 2× rise in xylose uptake and utilization by the cells. With comparative analysis of kinetic parameters in control and test experiments, this result was attributed to enhanced permeability of cell membrane that allowed faster diffusion of nutrients, substrates and products across cell membrane, higher enzyme-substrate affinity, dilution of toxic components and reduced inhibition of intracellular enzymes by substrate.

Starch as a natural polymer has attracted significant interest and is currently used in numerous industrial applications. This is because of its renewability, biodegradability, abundance, and cohesive film-forming properties. Moreover, the hydroxyl ( OH) groups associated with the anhydroglucose units provide it with several modification possibilities. These features have resulted in substantial interests for its use in several advanced functional material applications in addition to the typical consumer plastic applications. The goal of this review is to shed light on the recent advances achieved in the utilization of starch for advanced functional material applications and its derivatives. The review specifically focuses on applications ranging from electronics, drug delivery, pharmaceuticals, antimicrobial materials to structural materials.

The reinforcing effects of native and modified cellulose nanocrystal (CNC) materials on thermosetting epoxies are investigated. CNC modification is conducted by grafting an activated medium chain fatty acid to substitute the hydroxyl functional group. The level and effect of CNC modification are evaluated using Fourier Transform Infrared (FTIR), elemental analysis (EA), thermal analysis, contact angle measurements, and solvent dispersibility studies. The EA shows that CNCs with a degree of substitution (DS) of 0.2, 0.8 and 2.4 is obtained depending on the concentration of the catalyst and reactant used in the process. The native and modified CNCs are then incorporated into epoxy resin via an in situ polymerization. Dynamic mechanical analysis, and stress – strain studies showed that the lightly modified CNCs (DS 0.2 and DS 0.8) have an impressive reinforcing effect. CNC with DS 0.2 at 5% loading resulted in a 77% and 44% improvement in the tensile strength and modulus of the baseline epoxy matrix, respectively indicating significant reinforcement. Such materials can be useful in structural composites, printed circuit boards, and adhesive applications. An improvement in the dispersion and an enhanced interfacial adhesion between the modified CNC and the epoxy matrix is proposed for the observed reinforcement. A higher degree of fatty acid grafting onto the CNC resulted in a hydrophobic material, which reduced the water uptake of the epoxy nanocomposites.

Combustion of fossil fuels and many other industrial activities inevitably produces carbon dioxide (CO2) that is released into the atmosphere and is currently deemed to be among the major contributors to global warming. One of the prominent solutions proposed to mitigate global warming concerns from CO2, capture and storage (CCS), did not attract many CO2 emitting industries as expected, mainly because of economic reasons. On the contrary, environmental pollution concerns associated with plastic waste, and the demand for sustainable feedstock for their production constitute grand challenges facing our society with regard to the production and use of plastics. As a result, the materials science community is striving to generate sustainable and biodegradable plastics to substitute conventional synthetic plastics from resources that do not pose direct completion with food production. This manuscript aims to provide a general overview of the recent progress achieved in CO2 based polymers for sustainable biopolymers such as co-polymers, and polymer blends. The synthesis, material properties, processability, and performances of important CO2 based co-polymers are critically reviewed. Furthermore, a critical review of CO2 co-polymers as components of polymer blend with a focus on the most relevant CO2 based aliphatic polycarbonates, poly (propylene carbonates) (PPC), is conducted.

Manganese-based nanomaterials are an emerging new class of magnetic resonance imaging (MRI) contrast agents (CAs) that provide impressive contrast abilities. MRI CAs that can respond to pathophysiological parameters such as pH or redox potential are also highly in demand for MRI-guided tumor diagnosis. Until now, synthesizing nanomaterials with good biocompatibility, physiochemical stability, and good contrast effects remains a challenge. This study investigated two new systems of calcium/manganese cations complexed with either alginate–polydopamine or alginate–dopamine nanogels [AlgPDA(Ca/Mn) NG or AlgDA(Ca/Mn) NG]. Under such systems, Ca cations form ionic interactions via carboxylic acids of the Alg backbone to enhance the stability of the synthetic nanogels (NGs). Likewise, complexation of Mn cations also increased the colloidal stability of the synthetic NGs. The magnetic property of the prepared CAs was confirmed with superconducting quantum interference device measurements, proving the potential pa...

Carbon nanoparticles (CNP) were synthesized through flame deposition method from a sustainable corn oil precursor. The morphology, particle size, surface chemistry, thermal stability, and zeta potential of the CNP were characterized. The batch adsorption of a cationic dye, methylene blue (MB), by the CNP at various concentrations, pH, and temperatures was evaluated to investigate the CNP's efficacy in industrial wastewater treatment applications. Results revealed the excellent adsorption of MB onto the CNP. The experimental data were then fitted into isotherm models, kinetic models, and thermodynamic models, and the model parameters, constants, Gibb free energy, enthalpy, and entropy were calculated and discussed. Hydrogen bonding and strong electrostatic interaction were the main adsorption mechanism for MB adsorption by the CNP. The CNP exhibited a maximum adsorption capacity of 138.89 mg/g, indicating superior adsorption of MB dye without the need for any further purification and activation steps. The adsorption efficiency did not compromise as the solution temperature increased up to 60 °C, and it can further be enhanced under alkaline conditions. To simulate the practical and industrial use of the developed CNP in textile effluent treatment, successful experiments were conducted in continuous flow adsorption by allowing concentrated MB solution to flow through a designed fixed bed purification system with a CNP filter bed.

In a bid to develop environmentally-friendly rubber materials, the use of renewable and sustainable additives that could provide suitable mechanical property enhancement is of great interest. In this study, cellulose nanocrystals (CNCs) are employed as reinforcing fillers due to their availability, sustainability, and excellent mechanical properties. Various processing methods of natural rubber (NR) – CNCs nanocomposite formulations were anticipated to provide varying levels of dispersibility and hence physical properties. The effects of batch mixing, co-coagulation, and extrusion processing methods have been investigated and compared on the dispersion of CNCs in NR. Various physical property testing methods were also employed to understand the effects of the processing on the NR-CNC vulcanizates. While co-coagulation and extrusion provided improved reinforcement of the nanocomposites attributed to the optimal dispersion of CNCs, batch mixing processed samples exhibited poor dispersion even at low CNCs loadings as observed from transmission electron microscopy and inferior composite properties.

Graphical abstract, Highlights • Bacillus sp. strain CH12 is a potential candidate for dye removal. • Strain CH12 needs alkaline pH (9–10) to bring complete dye removal efficiency. • Organic carbon and nitrogen supplements enhance dye decolorization efficiency. • Sodium nitrite and sodium nitrate lead to lower decolorization efficiency. • Under oxygen tension conditions, dye can be used as a final electron accepter., Textile azo dye decolorizing bacteria were isolated from alkaline Lakes Abaya and Chamo using Reactive Red 239 (RR239) dye. Through subsequent screening process, strain CH12 was selected to investigate the effects of nutrient supplement, DO, pH, temperature, dye concentration and types on decolorization. Based on 16S rRNA gene sequence analysis, strain CH12 was identified as Bacillus sp. Decolorization efficiencies were significantly enhanced with carbon (≥98%) and organic nitrogen (∼100%) supplements. Complete decolorization was also observed under anoxic and anaerobic conditions, and at the temperature of 30 °C and the pH of 10. However, the azo dye decolorization efficiency of strain CH12 was significantly reduced when NaNO3 (1–8%) was supplemented or under aerobic culturing condition (≤6%), indicating that RR239 was less preferred electron acceptor. Overall, strain CH12 can be a promising candidate for decolorization applications due to its potential to effectively decolorize higher RR239 concentrations (50−250 mg/L) and six additional dyes.

Cobalt sulfide thin films were synthesized from acidic chemical baths by varying the deposition time. The powder X-ray diffraction studies indicated that there are hexagonal CoS, face-centered cubic Co3S4, and cubic Co9S8 phases of cobalt sulfide. The crystallite size of the hexagonal CoS phase decreased from 52.8 nm to 22.5 nm and that of the cubic Co9S8 phase increased from 11 nm to 60 nm as the deposition time increased from 2 hrs to 3.5 hrs. The scanning electron microscopic images revealed crack and pinhole free thin films with uniform and smooth background and few large polygonal grains on the surface. The band gap of the cobalt sulfide thin films decreased from 1.75 eV to 1.3 eV as the deposition time increased from 2 hrs to 3.5 hrs. The photoluminescence (PL) spectra of the films confirmed the emission of ultraviolet, violet, and blue lights. The intense PL emission of violet light at 384 nm had red shifted with increasing deposition time that could be resulted from the increase in the average crystallite size. The FTIR spectra of the films indicated the presence of OH, C-O-H, C-O, double sulfide, and Co-S groups. As the deposition time increased, the electrical resistivity of the cobalt sulfide thin films decreased due to the increase in both the crystallite size and the films’ thickness.

ZnS/glass and CdS/glass single layers and ZnS/CdS and CdS/ZnS heterojunction thin films were deposited by the chemical bath deposition method using zinc acetate and cadmium acetate as the metal ion sources and thioacetamide as a nonmetallic ion source in acidic medium. Na2EDTA was used as a complexing agent to control the free cation concentration. The single layer and heterojunction thin films were characterized with X-ray diffraction (XRD), a scanning electron microscope (SEM), energy dispersive X-ray (EDX), and a UV-VIS spectrometer. The XRD patterns of the CdS/glass thin film deposited on the soda lime glass substrate crystalized in the cubic structure with a single peak along the (111) plane. The ZnS/CdS heterojunction and ZnS/glass single layer thin films were crystalized in the hexagonal ZnS structure. The CdS/ZnS heterojunction thin film is nearly amorphous. The optical analysis results confirmed single band gap values of 2.75 eV and 2.5 eV for ZnS/CdS and CdS/ZnS heterojunction thin films, respectively. The CdS/glass and CdS/ZnS thin films have more imaginary dielectric components than the real part. The optical conductivity of the single layer and heterojunction films is in the order of 10 15 1/s. The optical study also confirmed refractive index values between 2 and 2.7 for ZnS/glass, ZnS/CdS, and CdS/ZnS thin films for incident photon energies between 1.2 eV and 3.8 eV. The surface morphology studies revealed compacted spherical grains covering the substrate surfaces with few cracks on ZnS/glass, ZnS/CdS, and CdS/glass and voids on CdS/ZnS thin films. The EDX result confirmed nearly 1 : 1 metallic to nonmetallic ion ratio in the single-layered thin films and the dominance of Zn ion over Cd ion in both ZnS/CdS and CdS/ZnS heterojunction thin films.

A novel monomer based, controlled enzymatic polymerization was employed to produce an engineered alpha-1,3 glucan polysaccharide. The structure and material properties of the engineered polysaccharide were characterized using various techniques. The use of such engineered polysaccharide as a reinforcing filler of polymers was evaluated using model polymers. For this, the alpha-1,3 glucan was incorporated into ethylene vinyl acetate co-polymer (EVA) matrices with vinyl acetate content of 32% and 40% via a melt processing fabrication process. Various mechanical and rheological properties of the fabricated composites were evaluated. The effect of vinyl acetate content of the EVA resin on the interaction with alpha-1,3 glucan that result in various performances attributes was also investigated and reported. The incorporation of alpha-1,3 glucan in these EVA composites resulted in the improvement of key composite properties, such as toughness, modulus, wear resistance, and hardness showing the reinforcing potential of these engineered polysaccharides.

The recent discovery of small interfering RNAs (siRNAs) has opened new avenues for designing personalized treatment options for various diseases. However, the therapeutic application of siRNAs has been confronted with many challenges because of short half-life in circulation, poor membrane penetration, difficulty in escaping from endosomes, and insufficient release into the cytosol. To overcome these challenges, we designed a diethylenetriamine (DETA)- and tetraethylenepentamine (TEPA)-modified polyamidoamine dendrimer generation 4.5 (PDG4.5), and characterized it using 1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear single-quantum correlation spectroscopy (HSQC), and Fourier transform infrared (FTIR) spectroscopy followed by conjugation with siRNA. The PDG4.5-DETA and PDG4.5-TEPA polyplexes exhibited spherical nanosize, ideal zeta potential, and effective siRNA binding ability, protected the siRNA from nuclease attack, and revealed less cytotoxicity of PDG4.5-DETA and PDG4.5-TEPA in HeLa cells. More importantly, the polyplexes also revealed good cellular internalization and facilitated translocation of the siRNA into the cytosol. Thus, PDG4.5-DETA and PDG4.5-TEPA can act as potential siRNA carriers in future medical and pharmaceutical applications.

Starch is an attractive biomacromolecule for functional materials due to its renewability, biodegradability, amenability for modification, and biocompatibility in mammalian cell lines. In this research, starch was proposed as a modular platform to produce antimicrobial polymer surfaces. Conjugation of biocidal molecules via chemical grafting onto starch (starch-g-biocide) and its antimicrobial properties in poly (lactic acid) (PLA) polymers were investigated. Polyhexamethylene guanidine hydrochloride (PHGH) was synthesized and used as an antimicrobial agent. The grafting was confirmed by FTIR, proton NMR, and elemental analysis. The modified starch was then incorporated into the PLA films at various concentrations, and the antimicrobial efficacy of these films were evaluated against a Gram-positive bacterium, Bacillus subtilis and a Gram-negative bacterium, Escherichia coli. The results showed that the polymer surfaces have high antimicrobial potency when bacteria contact them. This material therefore has great potential for self-decontaminating surfaces, such as medical devices and food packaging applications.

In this study, polypropylene (PP) was reprocessed at various cycles to simulate recycling to be used as a matrix for highly loaded wood plastic composites (WPC). The neat and composite samples were produced using a batch mixer and injection molder. The extent of PP recycling was analyzed using chromatography, rheology, microscopy, and other physical/mechanical properties. While successive thermo-mechanical processing caused considerable chain scission of the PP, shown by the reduction in melt viscosity and the average molecular weight. While, other properties like tensile strength and modulus did not change significantly. The repeated reprocessing allowed for the incorporate of high 70 wt% wood flour (WF) to produce highly filled WPC. Overall, the WPCs displayed appealing physical properties through the increase in hardness and stiff characteristics while reducing the composites elongation by ~17%. This indicates that the recycling of PP could be of great importance to reduce waste accumulation by producing WPCs for construction and other applications.

Nitric acid vapor phase oxidation of multi-walled carbon nanotubes (MWCNTs) was proposed as a promising technique to fabricate poly styrene-co-acrylonitrile (SAN)-grafted-CNTs via atom transfer radical polymerization (ATRP). The in-situ ATRP grafting approach was successfully employed to graft polystyrene (PS), SAN and polyacrylonitrile (PAN), onto the convex surfaces of pristine MWCNTs (PCNT) and acid-functionalized MWCNTs (FCNT). Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR), and thermogravimetric analysis (TGA) confirmed the effectiveness of the modification via the ATRP grafting approach. The molar composition of acrylonitrile in the synthesized copolymer on the surface of CNTs for an FCNTs was calculated to be about 80% and 67.5% by 1H-NMR and TGA respectively, whereas the value is lower for PCNTs. Morphological studies showed that SAN-grafted FCNTs exhibit rougher surface morphology compared to the SAN-grafted PCNTs. Moreover, the higher diameter of the FCNTs indicated the higher polymer content, which was coated onto CNTs functionalized by vapor-phase oxidation. Therefore, the vapor phase oxidation strategy employed in this study could be utilized as a general method to prepare CNTs which can serve as an ATRP macroinitiator for the fabrication of various polymer grafted CNTs.

The effectiveness of the simultaneous addition of carbon nanotubes (CNTs) and maleic-anhydride-grafted-ethylene propylene diene (EPDM-g-MA) with a maleation content of 0.4 wt% was evaluated on the toughness of two grades of polyamide6 (PA6) with different molecular weight. The samples were fabricated in the presence or absence of 1.5 wt. % of CNTs by melt-mixing using an internal mixer where the PA6/EPDM-g-MA content weight ratio was 100/0, 90/10, and 80/20. Scanning electron microscopy (SEM) revealed a rougher fracture surface by EPDM-g-MA with high-molecular-weight PA6 (HPA6) than low-molecular-weight PA6 (LPA6) as noted from the finer EPDM-g-MA particles owing to higher PA6/EPDM-g-MA interfacial adhesion. A remarkable decrease in EPDM-g-MA droplet size accompanied by shape transformation was also observed by the introduction of CNTs. Transmission electron microscopy (TEM) exhibited more homogeneous and fine CNT dispersion in the HPA6-based nanocomposites as compared to LPA6-based ones. Tensile results revealed that CNTs can counteract the plasticizing effect of EPDM-g-MA on Young’s modulus of the PA6. Though the presence of CNTs was expected to sacrifice the ductility, HPA6-based nanocomposite maintained reasonable levels of ductility owing to the absence of CNTs agglomerations. The crystallization study showed the nucleating and reinforcing effect of CNTs in the formulated system. The rheological test confirmed the effective CNT/polymer interaction with substantially higher G' and η* for HPA6-based nanocomposites. Dynamic mechanical studies suggested higher toughening effectiveness of EPDM-g-MA on HPA6 over LPA6 by the lower tanδmax peak height and Tg for the PA6 phase.

Localized cancer therapy with combination of drugs is an effective treatment modality which increase inhibition of tumor growth and reoccurrence. Recently, hydrogels that can encapsulate more than one drug for local sustain releases have been emerging as a compelling choice. In this study, DOX-loaded DMXAA conjugated mPEG-PLGA micelle (DOX-mPPD) was encapsulated in thermosensitive hydrogel prepared by blending carboxylic and amine terminal PDLLA-PEG-PDLLA copolymers and locally injected into tumor-bearing mice to assess the synergistic anti-vascular and immuno-chemotheraputic effects of DMXAA and DOX. The successful synthesis of the copolymers was confirmed by 1HNMR, APC, DOSY and UV spectroscopies. DOX loading capacity of mPPD micelle was relatively higher (6.79%) than mPEG-PLGA (mPP) micelle (6.09%). The cumulative releases of DOX and DMXAA from mPPD micelle at pH 5.5 were 77.34 ± 2.23% and 23.12 ± 0.9%, respectively upon 120 h. The release of DOX and DMXAA from the hydrogel was occurred in a sustained and sequential fashion with a cumulative release of 60.27 ± 87% and 44.55 ± 0.23%, respectively for 40 days. The in vitro cytotoxicity test against MDCK and HeLa cells verified the biocompatibilities of the copolymers for in vivo applications. More importantly, after a single intratumoral injection of various drug formulations into tumor bearing nude mice, hydrogel loaded with DOX-mPPD displayed the highest tumor suppression efficacy, lowest tumoral micro vessel density and increased serum TNF-α and IFN-β upon five weeks. Furthermore, histological analysis of major organs and body weight changes indicated that hydrogel based localized treatments didn’t cause significant systemic toxicities. Therefore, localized co-delivery of DOX and DMXAA with sequential release using hydrogels may be a promising approach for synergistic tumor suppression with minimal adverse effects.

This paper reports the use of cellulose nanocrystals (CNCs) and nanoclays as reinforcing fillers in starch ester (StE) films. The StE was prepared by a one-step homogenous esterification reaction to obtain a degree of substituted hydroxyl moieties of 2.8. StE films with varying concentrations (0, 0.5 wt.%, 1.5 wt.%, 3 wt.%, and 5 wt.%) of CNC and nanoclay were then fabricated using a solvent casting process and characterized using scanning electron microscopy, optical spectrometry, water absorbance, water vapor permeability, mechanical tests, and simulated compostability studies. The SEM images for the CNC-filled composites revealed aggregates of CNC in the matrix, while nanoclay showed a homogeneous dispersion. Although no apparent visible change in transparency was observed for all filled films, a decrease in light transmission was revealed by optical density measurements. The incorporation of the nanofillers improved the yield strength of the starch-ester films significantly. This improvement in the tensile strength was as much as 112 % and 173 % for 5 wt. % of CNC and 5 wt.% of nanoclay, respectively. No hydrolysis was observed for StE under the simulated composting conditions over six months. Compared to the unfilled StE films, the reinforced films showed a reduction in weight approximately equal to the amount of the filler, with a maximum degradation of 8.9 wt.% for the 5 wt. % nanoclay filled StE films.

A stiff, hydrophobic, and corrosion protective polyurethane (PU) nanocomposite coatings have been fabricated via the incorporation of surface modified cellulose nanocrystals (CNC). The modification of CNC involves surface grafting of varying levels of epoxy functionalized silane (ES). The effect of reaction time and concentration of ES on the level of grafting were evaluated using Fourier Transform Infrared Spectroscopy (FTIR), Elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), water contact angle measurement (WCA) and dispersibility test. It was found that prolonged reaction time and the high mole ratio of ES to CNC improve thermal properties and material wettability of the modified CNC. The incorporation of modified CNC in PU not only improved thermomechanical properties but also reduced the water absorption properties of the PU composites, which could be attributed to the improvement in the dispersion and enhanced interfacial adhesion between the nanoparticle and the PU matrix. Salt spray and electrochemical impendence spectroscopy (EIS) studies, which were carried out on mild steel coated with the fabricated nanocomposite (PU/ES-CNC), exhibited better anticorrosion behaviors as compared to PU. Overall, the CNC modification through silanization is a robust, eco-friendly, and scalable process, making it an appealing material for a range of polymer composite applications.

Poly(lactic acid) (PLA) was employed as wood fiber (WF) binder to fabricate thin-structured biocomposites via solvent-blending process and compression molding, with 50 to 80 wt.% WF contents. Also, adhesion improvement between the WF via enhanced wood fibers wetting with maleated PLA was employed. Overall, the mechanical properties of WF-PLA-MA biocomposites were improved in comparison to those of the WF-PLA. At higher WF loading, the strength was maintained for WF-PLA-MA while it reduced for WF-PLA. At 50 wt.% WF loadings, the storage modulus increased by 29% and the tan delta peak shifted to a higher temperature for the WF-PLA-MA as compared to those of the WF-PLA. Improved water-resistant of WF-PLA-MA, substantiated by a 7–17% reduction in thickness swelling of the sheets was observed as compared to WF-PLA. Overall, the thin-structured and highly filled wood-plastic composite presented appealing material properties for a range of applications including compostable crates, thermo-formable sheets for single use food utensil production etc.

Polypropylene (PP) and low-density polyethylene (LDPE) are among the most converted resins; as such, they also have the largest share in municipal waste fractions. Currently, there is a great societal and industrial need to recycle these polymers using thermo-mechanical processes. However, process-induced degradation during recycling operations may lead to irreversible changes. In this study, PP was blended with 0 to 10 wt.% of LDPE was subjected to consecutive twin-screw extrusion cycles (0 to 5 times) to mimic thermo-mechanical recycling. The effect of reprocessing on the rheological, thermal, and mechanical properties of PP/LDPE blends was investigated. An increase in MFR and decrease in viscosity was observed for PP and the blends. DSC results showed that the crystal structure of PP was seriously affected and generated more disorder with reprocessing. Although tensile properties were not substantially affected, all properties had a decreasing trend. While successive thermo-mechanical processing caused chain scission of the PP phase of the blend, the overall property of the studied blend composition maintained acceptable properties. Thus, recycling of PP with low PE blend additive is a feasible option not only to reduce plastic waste but also to generate value from an otherwise waste product.

Graphene, a single-atom thick, two-dimensional carbon material with remarkable properties is heavily used in advanced functional applications. However, production quality and processes are of concern, and the need for post-modification leads to high cost. Here, a novel production and simultaneous functionalization of few-layer graphene oxide-like nanosheets (FLGON) via a green process from biocarbons (BC) was synthesized. These nanosheets exhibit high crystallinity and flexibility, with few layer thickness of 3.67 nm and stiffness of 40 GPa. They are highly dispersible, forming a stable suspension in aqueous solutions due to abundant oxygen functional groups (34% oxygen content) on the surface structure. The lateral dimension of the nanosheets was estimated to be around 350 nm which was corroborated by the particle size analysis. Zeta potential was observed to remain the same regardless of the oxygenation of the BC at around 31 mV, indicating no formation of ions. A d-spacing of 0.339 nm indicated oxidation of the outer layers and edges of the FLGON with some interlayer oxidation. Properties of the FLGON suggest that it has potential applications in sensors, oxygen scavenging, nanocomposites and as a precursor for further modification. The sustainability of the biocarbons and environmentally friendly production process widens its application potential with reduced concern for economic sustainability.

Presently, environmental problems and regulations have caused awareness to producer liability concerning plastics recycling as they try to meet global demand. Process-induced degradation during recycling as well as degradation brought on by thermomechanical operations (e.g. extrusion, injection molding, etc.) or other processes typically leads to irreversible changes in the physicochemical properties and structure of the material. Thus, it is important to understand the magnitude and mechanisms of property deterioration during the recycling process via either chemical, thermomechanical, reutilization, or incineration methods while, looking into possible utilizations, applications, and solutions for the existing global accumulated polyolefine (PO) waste. This review provides a comprehensive overview of the recent research efforts and industrial trends in PO recycling. Although a wide variety of POs exist in the market, this review focuses on polyethylene (PE) and polypropylene (PP). The ongoing challenges and future potential of plastic recycling are also discussed.

Polymeric micelles (PMs) have been used to improve the poor aqueous solubility, slow absorption and non-selective biodistribution of chemotherapeutic agents (CAs), albeit, they suffer from disassembly and premature release of payloads in the bloodstream. To alleviate the thermodynamic instability of PMs, different core crosslinking approaches were employed. Herein, we synthesized the poly(ethylene oxide)-b-poly((2-aminoethyl)diselanyl)ethyl l-aspartamide)-b-polycaprolactone (mPEG-P(LA-DSeDEA)-PCL) copolymer which self-assembled into monodispersed nanoscale, 156.57 &plusmn, 4.42 nm, core crosslinked micelles (CCMs) through visible light-induced diselenide metathesis reaction between the pendant selenocystamine moieties. The CCMs demonstrated desirable doxorubicin (DOX)-loading content (7.31%) and encapsulation efficiency (42.73%). Both blank and DOX-loaded CCMs (DOX@CCMs) established appreciable colloidal stability in the presence of bovine serum albumin (BSA). The DOX@CCMs showed redox-responsive drug releasing behavior when treated with 5 and 10 mM reduced glutathione (GSH) and 0.1% H2O2. Unlike the DOX-loaded non-crosslinked micelles (DOX@NCMs) which exhibited initial burst release, DOX@CCMs demonstrated a sustained release profile in vitro where 71.7% of the encapsulated DOX was released within 72 h. In addition, the in vitro fluorescent microscope images and flow cytometry analysis confirmed the efficient cellular internalization of DOX@CCMs. The in vitro cytotoxicity test on HaCaT, MDCK, and HeLa cell lines reiterated the cytocompatibility (&ge, 82% cell viability) of the mPEG-P(LA-DSeDEA)-PCL copolymer and DOX@CCMs selectively inhibit the viabilities of 48.85% of HeLa cells as compared to 15.75% of HaCaT and 7.85% of MDCK cells at a maximum dose of 10 &micro, g/mL. Overall, all these appealing attributes make CCMs desirable as nanocarriers for the delivery and controlled release of DOX in tumor cells.

This paper describes a simple method to pattern nanoparticles on planar surfaces using the antifouling property of poly(ethylene glycol) monolayers deposited from a solution on the native oxide of titanium. Atomic force microcopy was used to pattern the poly(ethylene glycol) monolayers producing protein active sites on the protein-resistant surface. Patterns with different sizes have been generated by shaving the monolayers with different repetitions. Friction force microscopy was used to image the patterns. The smallest patterns are 50 nm and the largest patterns are 500 nm at full width half maximum. The smallest pattern was produced with one shave, whereas the largest pattern was produced by shaving the monolayers 112 times. Protein-coated nanoparticles were immobilised on the shaved (protein active) part of the monolayers by dipping the patterned samples into a solution that contains 2% by volume protein-functionalized nanoparticles with a nominal diameter of 40 nm. Atomic force microscopy was used to take a topographic image of the samples. The topographic image showed that the protein-functionalized nanoparticles were attached onto the shaved part of the substrate but not on the poly(ethylene glycol)-covered part of the substrate. The level of aggregation of the nanoparticles was also investigated from the topographic image. The section analysis of the topographic image of the nanoparticle patterns showed a height of 40 nm which proved that only a monolayer of particles were deposited on the shaved part of the monolayer.

Human mortality rates due to infectious diseases from drug-resistant bacterial strains is becoming an epidemic in our society. Currently, the development of new, expensive and more effective treatment processes and medications have stemmed from the impotence of antibiotics due to misuse and/or improper administration. This has consequently created a range of short- and long-term side effects in patients. On the other hand, nanoparticles have been shown to exhibit antimicrobial potency towards various types of pathogens due to their size and cell damaging abilities through various mechanisms. Unlike antibiotics, which are administered to treat diseases and infection in patients, nanomaterials provides an interesting opportunity to limit microbial growth prior to human infection. This has led to the development of engineered antimicrobial materials, targeting different applications with nanoparticles as the active antimicrobial agents. Hence, we critically reviewed the recent progress achieved in the use of engineered nanomaterials for antimicrobial applications and the mechanism that make them highly effective. Applications in water treatment, healthcare and facility substrates, alternative food packaging, and antifouling coatings have been given special attention due to their relevance as media through which diseases are easily spread. Likewise, drawbacks and knowledge gaps in nanomaterial solutions for antimicrobial materials are discussed.

Biodegradable polymers obtained from renewable natural resources have received increasing attention due to their potential as alternatives to traditional petroleum-based plastics. Among the various sources, polysaccharides stand out as a highly convenient feedstock because they are readily available, renewable, inexpensive, and provide great stereochemical diversity. Starch, a renewable polysaccharide polymer, has been well researched and attracted commercial interest as a feedstock due to its renewability, biodegradability, low cost, and abundance of –OH chemistry, leaving it open to endless modification possibilities and melt processability in the presence of plasticizers. However, its hydrophilicity, thermal, and mechanical properties limitations, rapid degradability, and strong intra and intermolecular hydrogen bonding of the polymer chains hinder its melt processability and limit its widespread commercial application as a renewable biopolymer. Therefore, modification is necessary to mitigate these limitations and bring about other desirable properties. This article critically reviews the recent progress achieved in the modification of starch for industrial biopolymer material applications where starch is used as one of the major constituents.

The need to transition to more sustainable and renewable technology has resulted in a focus on cellulose nanofibrils (CNFs) and nanocrystals (CNCs) as one of the materials of the future with potential for replacing currently used synthetic materials. Its abundance and bio-derived source make it attractive and sought after as well. CNFs and CNCs are naturally hydrophilic due to the abundance of -OH group on their surface which makes them an excellent recipient for applications in the medical industry. However, the hydrophilicity is a deterrent to many other industries, subsequently limiting their application scope. In either light, the increased rate of progress using CNCs in advanced materials applications are well underway and is becoming applicable on an industrial scale. Therefore, this review explores the current modification platforms and processes of nanocellulose directly as functional materials and as carriers/substrates of other functional materials for advanced materials applications. Niche functional attributes such as superhydrophobicity, barrier, electrical, and antimicrobial properties are reviewed due to the focus and significance of such attributes in industrial applications.

Metastasis is a pathogenic spread of cancer cells from the primary site to surrounding tissues and distant organs, making it one of the primary challenges for effective cancer treatment and the major cause of cancer mortality. Heparin-based biomaterials exhibit significant inhibition of cancer cell metastasis. In this study, a non-anticoagulate heparin prodrug is developed for metastasis treatment with a localized treatment system using temperature sensitive, injectable, and biodegradable (poly-(e-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(e-caprolactone-co-lactide) polymeric hydrogel. The drug molecule (heparin) is conjugated with the polymer via esterification, and its sustained release is ensured by hydrolysis and polymeric biodegradation. An aqueous solution of the polymer could be used as an injectable solution at below 25 °C and it achieves gel formation at 37 °C. The anti-metastasis effect of the hydrogels is investigated both in vitro and in vivo. The results demonstrated that local administration of injectable heparin-loaded hydrogels effectively promote an inhibitory effect on cancer metastasis.

Redox-responsive diselenide bond containing triblock copolymer Bi(mPEG-SeSe)-PCL,Bi(mPEG-SeSe)-PCL was developed for specific drug release in cancer cells. Initially, ditosylated polycaprolactone was prepared via the reaction between polycaprolactone diol (PCL-diol) and tosyl chloride (TsCl). Next, Bi(mPEG-SeSe)-PCL was synthesized via the reaction between ditosylated polycaprolactone and sodium diselenide initiated poly (ethylene glycol) methyl ether tosylate. The synthesized amphiphilic triblock copolymer could self-assemble into uniform nanoparticles in aqueous medium and disassemble upon redox stimuli. The Bi(mPEG-SeSe)-PCL nanoparticles showed a DOX loading content of 5.1 wt% and a loading efficiency of 49%. In vitro drug release studies showed that about 62.4% and 56% of DOX was released from the nanoparticles during 72 h at 37 °C in PBS containing 2 mg/mL (6 mM) GSH and 0.1% H2O2, respectively, whereas only about 30% of DOX was released in PBS under the same conditions. The cell viability (MTT assays) results showed that the synthesized material was biocompatible with above 90% cell viability, and that the DOX-loaded Bi(mPEG-SeSe)-PCL nanoparticles had a high antitumor activity against HeLa cells and low antitumor activity against HaCaT cells, following a 24-h incubation period. Three-dimensional (3D) spheroids of HeLa cells were established for the evaluation of localization of the DOX-loaded nanoparticles into spheroids cells and the successfully inhibition of 3D tumor spheroid growth. The results indicated that the synthesized material Bi(mPEG–SeSe)-PCL was biocompatible and it could be a potential candidate for anticancer drug delivery system.

Lavandula angustifolia is used in traditional and folk medicines of Ankober District, North Central Ethiopia, for the treatment of several livestock and human disorders. This toxicity study aimed to investigate L. angustifolia essential oil oral toxicity in mice and skin irritation in rabbit. L. angustifolia essential oil was analyzed using gas chromatography-mass spectrometry methods and showed predominance of Eucalyptol (52.36%), Camphor (11.91%), gamma-terpinene (8.775%) and endoborneol (7.585%). Limit test at 2000 mg/kg dose was used for L. angustifolia essential oil acute toxicity test and revealed LD50 value was higher than 2000 mg/kg. For subacute toxicity study 2000mg/kg was given orally to each mouse for 21 days. The result demonstrated no significant changes (p > 0.05) in the body weights, and biochemical parameters, gross abnormalities, water, and food intake were observed. No macroscopic changes were seen in the histopathology analysis of kidneys and livers. For skin irritation test shaved rabbit skin was treated with 10% ointment formulation. Ointment of L. angustifolia oil did not affect mice skin. Generally, this toxicity study demonstrated that L. angustifolia essential oil is nontoxic.

This study investigates ultrasonic enhancement of xylitol production from sugarcane bagasse using C. tropicalis MTCC 184 immobilized on PU foam. Initial xylitol yield of 0.53 g/g xylose improved to 0.65 g/g of xylose (in 36 h fermentation) after optimization of medium and fermentation parameters. Optimum values of experimental parameters for maximum xylitol were: yeast extract = 5.78 g/L, (NH4)2SO4 = 3.22 g/L, KH2PO4 = 0.58 g/L, MgSO4·7H2O = 0.57 g/L and temperature = 29.3 °C, initial pH = 6.2, agitation rate = 151 rpm and initial xylose concentration = 20.9 g/L. Application of 37 kHz sonication @10% duty cycle during fermentation at optimum conditions resulted in marked intensification of fermentation kinetics. Xylitol yield of 0.66 g/g of xylose has been obtained in ultrasound-assisted fermentation in just 15 h. Fitting of time profiles of substrates and products to kinetic model has highlighted actual physical mechanisms underlying 2-fold faster kinetics induced by sonication.

The main goal of this research was to utilize an inexpensive soymeal (SM) rather than an expensive purified soy protein isolate and soy protein concentrate for biobased and biodegradable sustainable film development. Green processing approaches of soymeal, with the aim of destructurizing its carbohydrates that are deterrent to plastic making, were conducted. This process involves natural fermentation (NF), yeast fermentation (YF), and simultaneous enzyme saccharification and fermentation (YEF). Soymeals treated as such were then plasticized with glycerol and blended with poly(butylene adipate-co-terephthalate) (PBAT). Compatibilization of the fermentation treated and plasticized soymeal with PBAT was also conducted via reactive extrusion. The resulting blended materials were then extrusion casted to produce films of 0.35 mm thickness. The performance of the film, including mechanical, thermal, morphology, and water resistance as a function of the fermentation treatments, and compatibilization were evaluat...

Over the past decades, strong global demand for industrial chemicals, raw materials and energy has been driven by rapid industrialization and population growth across the world. In this context, long-term environmental sustainability demands the development of sustainable strategies of resource utilization. The agricultural sector is a major source of underutilized or low-value streams that accompany the production of food and other biomass commodities. Animal agriculture in particular constitutes a substantial portion of the overall agricultural sector, with wastes being generated along the supply chain of slaughtering, handling, catering and rendering. The recent emergence of bovine spongiform encephalopathy (BSE) resulted in the elimination of most of the traditional uses of rendered animal meals such as blood meal, meat and bone meal (MBM) as animal feed with significant economic losses for the entire sector. The focus of this review is on the valorization progress achieved on converting protein feedstock into bio-based plastics, flocculants, surfactants and adhesives. The utilization of other rendering streams such as fat and ash rich biomass for the production of renewable fuels, solvents, drop-in chemicals, minerals and fertilizers is also critically reviewed.

Iron oxide-based magnetic resonance imaging (MRI) contrast agents have negative contrast limitations in cancer diagnosis. Gadolinium (Gd)-based contrast agents show toxicity. To overcome these limitations, Gd-doped ferrite (Gd:Fe3O4 (GdIO) nanoparticles (NPs) were synthesized as T1-T2 dual-modal contrast agents for MRI-traced drug delivery. A theranostics GdIO encapsulated in a Generation 4.5 PAMAM dendrimer (G4.5-GdIO) was developed by alkaline coprecipitation. The drug-loading efficiency of the NPs was ∼24%. In the presence of a low-frequency alternating magnetic field (LFAMF), a maximum cumulative doxorubicin (DOX) release of ∼77.47% was achieved in a mildly acidic (pH = 5.0) simulated endosomal microenvironment. Relaxometric measurements indicated superior r1 (5.19 mM−1s−1) and r2 (26.13 mM−1s−1) for G4.5-GdIO relative to commercially available Gd-DTPA. Thus, G4.5-GdIO is promising as an alternative noninvasive MRI-traced cancer drug delivery system.