Papers by Keyword: Hydrogel

Abstract: Antibacterial wound dressing has an important key in an infection in traumatic and surgical wounds. However, the antibacterial wound dressing is high cost and few domestic medical productions. The aim of this study is to prepare a wound dressing hydrogel from hybrid gelatin/carboxymethyl cellulose (Gel/CMC) hydrogel crosslinked with citric acid at different Gel: CMC ratios of 1:1, 1:2, 1:3, and 1:4 by solvent casting. The gel fractions and swelling of 6.0%w/v CuSO₄ loading hybrid Gel/CMC hydrogel (Cu-Gel/CMC hydrogel) were a maximum of about 44% to 53% and 85% to 245%, respectively. The results showed that the 1:1 Gel: CMC of hydrogel produce was the most suitable condition due to its good gel fractions and swelling behavior. The cumulative Cu²⁺ release was a maximum of about 45% in 7 days. The hybrid Cu-Gel/CMC hydrogel showed the zone of inhibition of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) about 16 mm and 19 mm, sequentially. The research provided that the hybrid Cu-Gel/CMC hydrogel has the potential to use in medical applications.

Abstract: This research aimes to synthesize photocatalyst-sodium alginate composite hydrogel beads which apply for coupled adsorption and photocatalytic degradation of organic residue. Fe₃O₄, graphitic carbon nitride (g-C₃N₄), grapheme oxide (GO) and AgNO₃ doped ZnO photocatalyst composites hydrogel beads were synthesized and characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). Photocatalytic and adsorption activity are studied by Methylene blue (MB) degradation under sunshine irradiation. The effect of different parameter as photocatalyst types and reaction time were studied upon the efficiency of organic residue degradation. The coupled photocatalytic and adsorption processes were evaluated through various kinetic models such as pseudo-first-order/ pseudo-second-order in Langmuir-Hinshelwood model model, the Elovich model and the intra particle diffusion model. Kinetics studies showed that the coupled photocatalytic and adsorption processes in photodegradation of all sample was well described by the pseudo-second-order model because R² of all sample were close to 1 which compared with another model. For photodegradation efficiency, the best choice in this condition was g-C₃N₄ doped ZnO composite hydrogel bead. Photodegradation efficiency and the pseudo second order rate constant of photocatalyst ZnO+gC₃N₄/SA composite hydrogel bead were 83.80%(for 180 min and up to 96% for 7 hr) and 5.05×10^-3 g.mg^-1 min^-1, respectively.

Abstract: Smart polymers have been one of the most popularly studied materials owing to their capability to alter physio-chemical behaviour upon exposure to specific external stimuli. The biocompatible thermally responsive poly (N-isopropylacrylamide), PNIPAm shows reversible transition between hydrophilic-hydrophobic characteristics at the vicinity of human physiological temperature has great potential to propel the development of smart tissue engineering scaffold and drug delivery. However, the limited availability and its high cost have dampened the extent of research on this polymer. To address these challenges, the current work demonstrates an economical lab-scale polymerization of crosslinked PNIPAm and the optimised parameters to produce mono-dispersed polymer hydrogel particles were investigated. Characterisation of the synthesized PNIPAm polymer revealed particle size polydispersity index of 0.215, indicative of distribution within the mono-dispersed range, with average hydrodynamic diameter of 346.3 nm. Zeta-potential of the synthesized PNIPAm was found to be -20.6 mV, suggesting an incipient instability in terms of colloidal coagulation. Viscosity of the synthesized PNIPAm (4 wt% concentration in methanol) was 28.6 cP. Thermal gravimetric analysis (TGA) indicated the thermal degradation of main chain PNIPAm fell in the range of 340 to 480°C.

Abstract: This research is based on the creation of copper oxide nanoparticles (CuO-NPs) hydrogel through in situ method. The effective UV-Vis spectroscopy absorption peak of 610 nm indicates the existence of copper oxide nanoparticles (CuO-NP) group because of surface Plasmon resonance (SPR). Characterization of CuO-NPs was carried out by SEM, TEM, EDX, and XRD. However, the action of prepared nanocomposite hydrogels swelling was examined at different pH and saline solutions. In addition, CuO-NPs were also tested using the disk plate diffusion method by means of adverse effect of bacteria Gram-positive bacteria (Bacillus subtilis) as well as Gram-negative bacteria (Escherichia coli). The CuO-NPs hydrogels isolated from lab-made CMC (made from sugarcane bagasse) indicates that the Bacillus subtilis as well as Escherichia coli have greater antibacterial activity compared with synthetic CMC purchase from the market. CuO-NPs can be used effectively in biomedical applications with the production of hydrogels.

Abstract: Physically crosslinked superabsorbent hydrogels based on NaCMC, HPC, and NaAlg were developed to address the effects of water shortage to crop farming and to regulate fertilizer usage. An optimized synthesis was performed using ten different blends. The blend with a NaCMC/HPC/NaAlg ratio of 0.29/0.42/0.29 was found to exhibit the most favorable results, accommodating 1585% moisture and 8.38% fertilizer on a dry basis. Scanning electron microscope images of this blend manifested microporous structures, responsible for its superabsorbent properties. It was found out that applying the hydrogel at 5% loading to silt soil decreases fertilizer runoff by 28% and increases field capacity to 55%. Moreover, phytotoxicity studies showed that the optimum hydrogel blend exhibits no phytotoxic properties to pechay (Brassica rapa subsp. chinensis), lettuce eton (Lactuca sativa), and spinach (Spinacia oleracea), proving its applicability to agriculture.

Abstract: Providing enough water in farming has become a challenge in the Philippines due to insufficient irrigation and escalating drought conditions, thereby decreasing agricultural productivity. The impact of this problem can be lessened through efficient water usage: by reducing water wastage in runoff or evaporation and improving soil water retention. Hydrogels can be used for this purpose due to their water absorption capabilities. In this study, a novel, biodegradable agricultural hydrogel was developed from κ-carrageenan, sodium alginate and carboxymethyl cellulose, crosslinked with Ca²⁺ and K⁺ ions. Scanning electron microscopy analysis confirmed the successful crosslinking while swelling tests revealed them as superabsorbent hydrogels, with maximum absorption reaching 2000%. Soil amended with 2% (w/w) hydrogel showed reduced water-depletion rate and improved field capacity by a maximum of 17.6% and 17.4%, respectively. Fertilizer release test also showed the potential of these hydrogels as fertilizer carriers.

Abstract: Hydrogel is very popular used in medicinal materials due to their properties. The aim of study is to investigate the development of chitosan (CS) hydrogel beads to extend drug-releasing time and enhance the stability of hydrogel beads from decomposition due to surrounding temperature. Gentamicin (GM) is using as a drug model for loading and releasing from hydrogel beads. For this purpose, the effects of ionic gelation of CS and tripolyphosphate (TPP) on various concentrations (1, 3, 5, and 7%w/v) are emphasized. Scanning electron microscopy (SEM) has revealed that CS hydrogel beads are roughly surface with decreasing of the %CS content. The Fourier transform infrared (FT-IR) spectra show a weak band of hydroxyl stretching at 2878 cm^-1 of chitosan, the absorption band of the carbonyl stretching of the secondary amide at 1651 cm^-1. The releasing solution of CS hydrogel beads exhibit an antimicrobial activity against 4 type of bacterias compared to Chloramphenical. For this reason, indicating that CS hydrogel beads are an appropriate for controlled drug release system to turmeric crude extract.

Abstract: Hydrogel composed of gelatin, chitosan, and honey can be one of the right candidates for wound dressing application which provides both an antibacterial and a proper wound drainage management property to promote faster healing. Herein, preparation of hydrogel has been conducted by the physical blending of the solution of gelatin, chitosan, and honey at 40°C. Then, the mixture was cast to form hydrogel films by each 2-4 mm thickness and followed by drying at 37^o C for 24 hours. The resulted hydrogels were characterized to confirm its potential as wound care dressing by measuring gel fraction, swelling index, and antibacterial activity. The gel fraction of the hydrogel composed of 10 and 20 grams of gelatin (each with 0.5 grams of chitosan and 20 grams of honey) was respectively 68.86 % and 65.68%. The hydrogel, composed of 20 g of gelatin and 7.5 g of chitosan, has shown the highest water retention capacity (swelling index) by 400 %. However, the presence of honey has slightly lowered both the gel fraction and swelling index of the resulted hydrogel. The antibacterial property of the resulting hydrogel in this work corresponds to the chitosan instead of honey and gelatin.

Abstract: Uncontrolled hemorrhage is the leading cause of death. The efficient hemostatic dressings are needed to promote coagulation and hold ongoing hemorrhage. Hydrogels are hydrophilic polymers with three-dimensional network structures with high swelling capacity to prevent accumulation of exudates. Hydrogels prepared from polyvinyl alcohol (PVA) grafted with chitosan have attracted considerable attentions due to their biocompatibility, high moisture balance property, and transparency. In this study, alginate was utilized to improve elasticity and thermal stability, also enhance hydrophilicity and increase swelling ability. The hydrogels composed of PVA (7.5 % w/v), chitosan (0.05 % w/v), and alginate (0.2, 0.4, and 0.6 % w/v) were synthesized by gamma irradiation technique at total dose of 15 kGy. The results showed that the increasing of alginate concentration in the total reactant mixture can improve elasticity, swelling capacity and the equilibrium degree of swelling (EDS), and decrease water vapour transmitted rate/moisture vapour transmitted rate (MVTR). The hydrogel wound dressing with 0.6 % of alginate concentration was the best product in this study with 79.49 % gel content, 608.65 % swelling ratio, 628.32 % EDS in 22 hours, elasticity 62.58 KPa, evaporation rate (MVTR) 105g/m2 h, degraded at temperature of 298.89oC, and the weight loss was reached 88.84 % (w/w).

Abstract: In this work, a hydrogel-based optical leaky waveguide (OLW) biosensor was developed to detect biomolecules using changes in refractive index (Dn). Hydrogels formed from chitosan and agarose were synthesised to be used as a waveguiding thin film in OLW biosensor. The concentration and thickness of the hydrogels defined by the spin coater speeds and time were optimised to produce a device chip with a single waveguide moded operation of OLW biosensor. The cladding layer was fabricated using 9.5nm titanium coated glass substrate for metal-clad (MCLW) and addition of dye particles (reactive blue 4) for dye-clad (DCLW) format. For the performance of the fabricated device for detection of Dn of a glycerol solution, the highest sensitivity of detection was obtained from MCLW chip made of 2% w/v of chitosan-agarose hydrogel spun at 6000 rpm with LOD: 4.28 x 10^–6 RIU, while for DCLW format, the LOD measured at 7.46 x 10^–6 RIU. The performance of the device to monitor the protein (bovine serum albumin; BSA and anti-BSA) interaction, the binding affinity in respect of change in peak angle (DӨ°) of chitosan matrix to the protein was measured at DӨ°~(6.2 ± 0.5°)x10^–6.