Curcumin was loaded onto starch nanoparticles by using in situ nanoprecipitation method and water-in-oil microemulsion system. Curcumin loaded starch nanoparticles exhibited enhanced solubility in ...aqueous solution as compared to free curcumin. Effects of formulation parameters such as types of reaction medium, types of surfactant, surfactant concentrations, oil/ethanol ratios, loading time, and initial curcumin concentration were found to affect the particle size and loading efficiency (LF) of the curcumin loaded starch nanoparticles. Under optimum conditions, curcumin loaded starch nanoparticles with mean particles size of 87 nm and maximum loading efficiency of 78% were achieved. Curcumin was observed to release out from starch nanoparticles in a sustained way under physiological pH over a period of 10 days.
In this study, pH responsive carboxylic cellulose acetate nanoparticles (CCA NPs) have been evaluated as drug nanocarriers for controlled release of drug. Herein, carboxylic cellulose acetate (CCA) ...was initially synthesized via oxidation of cellulose using a 2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl (TEMPO) as an oxidant and followed by the acetylation of carboxylic cellulose in the presence of iodine as a catalyst. CCA NPs were then obtained via the nanoprecipitation process and subsequent sonication. The obtained CCA NPs with a mean diameter of 96 nm were subsequently evaluated as drug delivery nanocarriers. Penicillin G as a model drug was loaded onto the CCA NPs via the adsorption process. Drug release profiles of Penicillin G from CCA NPs were evaluated in phosphate buffer solution (PBS) at different medium pH values (1.2, 7.4, and 8.6). Release kinetic models were applied to determine the release mechanism of penicillin G from loaded CCA NPs. Results showed that pH-responsive release of penicillin G from CCA NPs which was released most slowly at medium of pH 7.4.
Cellulose films with antimicrobial property were prepared by incorporation of chitosan nanoparticles as antimicrobial agents into the cellulose films. The antimicrobial property of these chitosan ...nanoparticles-doped cellulose films against Escherichia coli (E. coli) was evaluated via diffusion assay method, minimum inhibitory concentration (MIC) method, and minimum bactericidal concentration (MBC) method. The effects of antimicrobial agent amount, size-related property (nanoparticles and bulk chitosan), and crosslinking by citric acid on antimicrobial activity of cellulose films were studied. It was observed that the antimicrobial activity was enhanced when chitosan nanoparticles were used as compared to when bulk chitosan was used. A maximum E. coli inhibition of 85% was achieved with only 5% (v/v) doping of chitosan nanoparticles into the cellulose films. Crosslinking of the cellulose films with citric acid was observed to have resulted in 50% reduction of water absorbency and a slight increase of E. coli inhibition by 3% for chitosan nanoparticles-doped cellulose films.
Controllable particles sizes of starch nanoparticles were synthesized via a precipitation in water-in-oil microemulsion approach. Microemulsion method offers the advantages of ultralow interfacial ...tension, large interfacial area, and being thermodynamically stable and affords monodispersed nanoparticles. The synthesis parameters such as stirring rates, ratios of oil/cosurfactant, oil phases, cosurfactants, and ratios of water/oil were found to affect the mean particle size of starch nanoparticles. Starch nanoparticles with mean particles sizes of 109 nm were synthesized by direct nanoprecipitation method, whereas by using precipitation in microemulsion approach, starch nanoparticles with smaller mean particles sizes of 83 nm were obtained.
A large amount of sago pith waste (SPW) produced by the growing sago industry has become an environmental concern. Instead of disposing as waste, SPW could be converted into a hydrogel and used as a ...seed germination medium. In this study, a hydrogel was prepared from SPW cellulose fibres via crosslinking with epichlorohydrin (ECH). Fourier transform infrared (FTIR) characterisation showed that pure cellulose fibres extracted from the SPW were successfully crosslinked with ECH to form the hydrogel. Scanning electron microscope (SEM) micrograph of the hydrogel showed a porous microstructure. The optimum hydrogel swelling ratio at 19.9 g g-1 was obtained with 5% w/v SPW cellulose content and 5 ml ECH. In this study, the hydrogel hydration property was demonstrated by using it as a medium for maize seed germination. The germination rate (GR) was observed to be above 70% when SPW cellulose hydrogel alone was used as the medium without the needs for frequent watering.
Cellulose acetate nanoparticles (CCA NPs) with mean particles sizes of 97 nm were synthesized via the nanoprecipitation process. The antibacterial properties of these CCA NPs were evaluated against ...Gram (+) and Gram (-) bacteria, respectively. The CCA NPs exhibited good antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) (+), Staphylococcus epidermis (+), Escherichia coli (-), Bacillus cereus (+), and Salmonella typhimurium (-) in range of MIC of 2.5×102 to 5.0×102 µg.mL-1 and MBC of 5.0×102 to 1.0×103 µg.mL-1. Penicillin G (PenG)-loaded CCA NPs demonstrated synergistic antibacterial activities against Gram (+) and Gram (-) bacteria. PenG-loaded CCA NPs also exhibited promising antimicrobial activity against the Methicillin-resistant staphylococcus aureus (MRSA) superbug, which is resistant to penicillin G. These promising antibacterial properties suggested that CCA NPs could potentially serve as an alternative potent antimicrobial agent for both Gram (+) and Gram (-) bacteria as well as the superbug MRSA.
Synthesis parameters have a significant effect on the properties of cellulose hydrogel. This study aimed to investigate the effects of synthesis parameters, e.g., the cellulose and crosslinkers ...concentration, on the hydrogels' swelling ratio under both heating and freezing gelation conditions, respectively. Cellulose hydrogels were prepared from wastepaper by the chemical crosslinking method by using epichlorohydrin ECH as a crosslinker. The effects of the synthesis parameters were compared and optimized by response surface methodology (RSM). Synthesized cellulose-based hydrogels under optimized conditions demonstrated an excellent swelling ratio of around 2800%. The optimum swelling ratio of 2467.72% was achieved from the experiment under the heating gelation condition. Thus the synthesized cellulose hydrogels are promising water-saving materials or controlled-release fertilizer carriers for sustainable horticultural and agricultural applications.
Superparamagnetic magnetite nanoparticles are coated with homogeneous gold and silver shells using a simple aqueous based seed mediated method at room temperature with dopamine as a surfactant. ...Nanoparticles of Au in the range 2−3 nm are attached to amine functionalized Fe3O4 nanoparticles, acting as seed for the growth of ultrathin Au or Ag shells. The monodispersed core−shell nanoparticles Fe3O4@Au and Fe3O4@Ag have a particle size range of 10−13 nm with a shell thickness of approximately 2−3 nm. They are magnetically purified and are superparamagnetic at 300 K with saturated magnetization values of 41 and 35 emu g−1, respectively.
This paper reported the fabrication of starch-based nanofibers derived from various weight ratios (w:w) of native sago starch (SS) and poly (vinyl alcohol) (PVA) (0:100, 1:100, 3:100, and 5:100) ...using the electrospinning technique. The effects of electrospinning operation parameters on the surface morphology of SS/PVA nanofibers were observed by using Scanning Electron Microscopy (SEM). The smooth and bead-free SS/PVA nanofibers with fiber diameters within the range of 90 nm to 150 nm were produced under the optimized conditions. The paracetamol (PCM) was encapsulated into the SS/PVA nanofibers via the blending process. The SS/PVA nanofibers exhibited a maximum PCM loading capacity of 0.9573 mg.mg-1, and PCM was observed to release out from SS/PVA nanofibers slowly and steadily for 72 hours.
PDF
