Effect Of Crosslinking Agents Research Articles

Effect of Crosslinking Agents on Chitosan Hydrogel Carriers for Drug Loading and Release for Targeted Drug Delivery.

Numerous studies report on chitosan hydrogels in different forms, such as films, porous structures, nanoparticles, and microspheres, for biomedical applications; however, this study concentrates on their modifications with different crosslinking agents and observes their effects on drug loading and releasing capacities. Linear chitosan, along with chitosans crosslinked with two major crosslinkers, i.e., genipin and disulfide, are used to formulate three different hydrogel systems. The crosslinking process is heavily impacted by temperature and pH conditions. Three different drugs, i.e., thymoquinone, gefitinib, and erlotinib, are loaded to the hydrogels in de-ionized water solutions and released in phosphate-buffered solutions; thus, a total of nine combinations are studied and analyzed for their drug loading and releasing capabilities with ultraviolet-visible (UV-Vis) spectroscopy. This study finds that thymoquinone shows the lowest loading efficacy compared to the two other drugs in all three systems. Gefitinib shows stable loading and releasing regardless of crosslinking system, and the genipin-crosslinked system shows stable loading and releasing with all three drug molecules. These experimental results agree well with the findings of our previously published results conducted with molecular dynamics simulations.

Preparation of Waterborne Silicone-Modified Polyurethane Nanofibers and the Effect of Crosslinking Agents on Physical Properties.

Silicone-modified polyurethane (PUSX) refers to the introduction of a silicone short chain into the polyurethane chain to make it have the dual properties of silicone and polyurethane (PU). It can be used in many fields, such as coatings, films, molding products, adhesives, and so on. The use of organic solvents to achieve the fiberization of silicone-modified polyurethane has been reported. However, it is challenging to achieve the fiberization of silicone-modified polyurethane based on an environmentally friendly water solvent. Herein, we report a simple and powerful strategy to fabricate environmentally friendly waterborne silicone-modified polyurethane nanofiber membranes through the addition of polyethylene glycol (PEG) with different molecular weights using electrospinning technology and in situ doping with three crosslinking agents with different functional groups (a polyoxazoline crosslinking agent, a polycarbodiimide crosslinking agent, and a polyisocyanate crosslinking agent) combined with various heating treatment conditions. The influence of PEG molecular weight on fiber formation was explored. The morphology, structure, water resistance, and mechanical properties were analyzed regarding the effect of the introduction of silicone into PU. The effects of the type and content of crosslinking agent on the morphology and physical properties of PUSX nanofiber membranes are discussed. These results show that the introduction of silicone can improve the water resistance and high temperature resistance of waterborne PU, and the addition of a crosslinking agent can further improve the water resistance of the sample, so that the sample can maintain good morphology after immersion. Crosslinking agents with different functional groups had different effects on the mechanical properties of PUSX nanofiber membranes due to different reactions. Among them, the oxazoline crosslinking agent had a significant effect on improving tensile strength, while the isocyanate crosslinking agent had a significant effect on improving the elongation at break. The PUSX nanofiber membrane prepared in this work did not use organic solvents that were harmful to humans and the environment, and it can be used in outdoor textiles, oil-water separation, medical health, and other fields.

Effect of cross-linking agents on sodium alginate-based quercetin beads: physicochemical properties and controlled release kinetics

Alginates have a variety of biological, physical, and chemical properties that can be modified to meet a specific purpose. Ionic crosslinking is an easy method of alginate modification. This study examined the ionic crosslinking agents (Ca2+, Ba2+, Mg2+) on swelling ratio, water solubility, and % sol-gel fraction of modified alginate. The performance of the modified alginate used to encapsulate quercetin, such as % encapsulation efficiency (% EE), % release of quercetin, and quercetin release kinetics were examined. The variables used in this study were the concentration of alginate and ionic crosslinking agents. At 3% alginate concentration and 0.3 M, ionic crosslinking agent concentration positively correlated with swelling ratio and water solubility. In contrast, the ionic crosslinking agent that positively correlates to the % sol-gel fraction is Ca2+. Encapsulation of quercetin using a crosslinking agent with ion Ca2+ and 2.5 ppm of quercetin concentration showed the highest % EE of 87%. Modified alginate induced quercetin release from beads at pH 1.4 and 7. The release of quercetin from modified alginate followed the Korsmeyer-Peppas kinetic model (R2 >0.99). The results of the FTIR analysis confirmed that a new peak at 1271 cm-1 was C-O-C characteristic of quercetin, indicating quercetin loaded on encapsulated beads. The morphological analysis showed that the surface of modified alginate (Ca-Ag/Ba-Ag/Mg-Ag) was rough and porous. This study established that modified alginate using different ionic crosslinking agents can be a suitable matrix for encapsulating quercetin.

The Effects of Cross-Linking Agents on the Mechanical Properties of Poly (Methyl Methacrylate) Resin.

Cross-linking agents are incorporated into denture base materials to improve their mechanical properties. This study investigated the effects of various cross-linking agents, with different cross-linking chain lengths and flexibilities, on the flexural strength, impact strength, and surface hardness of polymethyl methacrylate (PMMA). The cross-linking agents used were ethylene glycol dimethacrylate (EGDMA), tetraethylene glycol dimethacrylate (TEGDMA), tetraethylene glycol diacrylate (TEGDA), and polyethylene glycol dimethacrylate (PEGDMA). These agents were added to the methyl methacrylate (MMA) monomer component in concentrations of 5%, 10%, 15%, and 20% by volume and 10% by molecular weight. A total of 630 specimens, comprising 21 groups, were fabricated. Flexural strength and elastic modulus were assessed using a 3-point bending test, impact strength was measured via the Charpy type test, and surface Vickers hardness was determined. Statistical analyses were performed using the Kolmogorov-Smirnov Test, Kruskal-Wallis Test, Mann-Whitney U Test, and ANOVA with post hoc Tamhane test (p ≤ 0.05). No significant increase in flexural strength, elastic modulus, or impact strength was observed in the cross-linking groups compared to conventional PMMA. However, surface hardness values notably decreased with the addition of 5% to 20% PEGDMA. The incorporation of cross-linking agents in concentrations ranging from 5% to 15% led to an improvement in the mechanical properties of PMMA.

Effect of cross-linking agents on the adsorption of histamine on molecularly imprinted polyacrylamide

The ability of molecularly imprinted polymers (MIPs) prepared with flexible cross-linking agents for selective uptake of guest molecules is investigated. New polyacrylamide polymers had been synthesized for histamine (HA) extraction using solid supports based on MIPs immobilized on silica surface (SiO2). The MIPs were prepared via radical polymerization in acetonitrile and in the presence of azobisisobutyronitrile (AIBN) as initiator, using HA as a target molecule, acrylamide as a functional monomer and several cross-linking agents having alkyl spacers of various lengths: N,N′-methylenebisacrylamide (BA1), N,N′-ethylenebisacrylamide (BA2), N,N’-(butane-1,4-diyl)-bis(2-methacrylamide) (BA4) and N,N’-(hexane-1,6-diyl)-bis(2-methacrylamide) (BA6). All the prepared MIPs have a strong absorption capacity of HA compared to non-imprinted polyacrylamide (NIPs). MIP4 made with the BA4 cross-linker shows a higher selectivity for adsorption of HA than MIPs made with BA1, BA2 and BA6. Thus, the imprinting factor for adsorption from a 5 ppm HA solution was 2.5 for MIP4 against 1.4 to 1.6 for MIP1, MIP2 and MIP6. Langmuir–Volmer and Volmer models of the adsorption isotherms of MIPs and NIPs accurately fit the experimental data. They provide the characteristic parameters of the adsorption thermodynamic of the materials. The higher performance of MIP4 for selective adsorption of HA is mainly coming from a higher density of molecular imprints (1.4 μmol m−2 against 0.13–0.15 μmol m−2 for MIP1 and MIP2 and 0.4 μmol m−2 for MIP6) than a higher affinity of HA for the molecular imprints. The selectivity with respect to the tyramine and melamine interfering molecules is also higher for MIP4. As the main outcome, some moderate flexibility of the material is advantageous. Such flexibility allows for a reversible healing and re-opening of the molecular imprints as the HA guest is removed and back-adsorbed.

Cross-linked Alginate Beads of Montelukast Sodium Coated with Eudragit for Chronotherapy: Statistical Optimization, In vitro and In vivo Evaluation.

Chronotherapy is the administration of medication according to the biological rhythm to maximize pharmacological effects and minimize side effects. The objective of the current investigation is to prepare delayed-release beads (DRBs) containing montelukast sodium (MKS) for chronotherapy of asthma. Delayed-release beads of alginate were prepared using a simple method, i.e., ionotropic gelation. The effect of cross-linking agents (zinc or calcium ions) and the concentration of chitosan on the properties of the beads were investigated. The prepared beads were coated by a polymer having pHindependent solubility, i.e., Eudragit RSPO and Eudragit RLPO in different ratios to achieve the desired lag time of 4-5 h. Beads were evaluated for surface morphology, practical yield, encapsulation efficiency, XRD, and in vitro release study. The pharmacokinetic study was carried out on New Zealand white male rabbits. No major differences in the drug release profile were observed between Ca++ and Zn++ crosslinked beads. However, a slight slow release was seen in the case of chitosan-reinforced beads. MKS released from cross-linked alginate beads was slightly altered with sodium alginate concentration, crosslinking time, and talc. At a higher alginate concentration, slow drug release was observed, whereas the addition of talc to alginate increased the release rate. The in vitro release study showed that the optimal formulation of DRBs has a lag time of 4.5 h, and the release at 6 h was found to be 74.9%. In vivo pharmacokinetic study of the beads showed Tmax at 7 h with an initial lag time of 4 h. When dosed at sleep time, the prepared cross-linked beads may deliver montelukast sodium required to relieve early morning symptoms in asthmatic patients.

Effects of cross-linking agents and radiopacifying fillers on degree of conversion and volumetric shrinkage of denture based methacrylic resins

"Development of experimental dental prostheses formulations based on methacrylic resins. The effect Study, on the degree of conversion (DC) and volumetric shrinkage (VS), of four crosslinking agents: DEDGMA, TEGDMA, TETRAEGDA and TMPTA and four radiopacifying mineral fillers: ZrO2, TiO2, SrO and BaO2. The experimental resins are compared to commercial products. The (DC) determination of the experimental and commercial resins was carried out by FTIR in ATR mode. The (VS) was determined experimentally by the Archimed’s method. Chemical structure and weight content of crosslinking agents affected (DC) and (VS). (DC) and (VS) increased with the crosslinking agent chain length and weight contents. Additionally, whatever filler contents and metal nature, (DC) values remains ≥ 99.5%, in accordance with the standards required for residual monomers level tolerated in dental prostheses (<0.45%). (VS) values varied between 4,8 and 10,8%. For two commercial resins, (DC) values were less than 99% while (VS) was in accordance with the standards (5-6%): 6.2% for Major base and 4.3% for Hiflex H."

The Effect of Crosslinking Agents on the Properties of Type II Collagen Biomaterials

Type II collagen has been perceived as the indispensable element and plays a crucial role in cartilage tissue engineering. Thus, materials based on type II collagen have drawn farther attention in both academic and research for developing new systems for the cartilage regeneration. The disadvantage of using type II collagen as a biomaterial for tissue repairing is its reduced biomechanical properties. This can be solved by physical, enzymatic or chemical cross-linking processes, which provide biomaterials with the required mechanical properties for medical applications. To enhance type II collagen properties, crosslinked collagen scaffolds with different cross-linking agents were prepared by freeze-drying technique. The present research work studied the synthesis of type II collagen biomaterials with and without crosslinking agents. Scaffolds morphology was observed by MicroCT, showing in all cases an appropriate microstructure for biological applications, and the mechanical studies were performed using compressive tests. DSC showed an increase in denaturation temperature with an increase in cross-linking agent concentration. FTIR suggested that the secondary structure of collagen is not affected after the cross-linking; supplementary, to confirm the characteristic triple-helix conformation of collagen, the CD investigation was performed. The results showed that the physical-chemical properties of type II collagen were improved by cross-linking treatments.

Effect of Crosslinking Agents on the Physicochemical and Digestive Properties of Corn Starch Aerogel

AbstractIn this study, sodium trimetaphosphate, adipic acid, sodium hexametaphosphate, and epichlorohydrin (EPI) are used to investigate the effect of the crosslinking reaction on the physicochemical properties and in vitro digestibility of corn starch aerogel (CSA). Gelatinization destroys the morphology of the corn starch granules, and the crosslinking reaction which is performed in the gelatinization stage considerably alters the structure of the gel. The aerogel prepared by adding 0.5% EPI shows the highest Brunauer–Emmett–Teller surface area among the crosslinked starch aerogels. Corn starch xerogels and aerogels all have porous network structures which may be related to the high amylose structure of corn starch. Gelatinization and crosslinking agents disrupt the short‐range molecular order of corn starch, and the crosslinked CSA has relatively lower crystallinity and higher swelling power and solubility than the control. After crosslinking, rapidly digestible starch and resistant starch content of CSAs increase, while slowly digestible starch decreases slightly. Thus, the crosslinked CSA may be used for encapsulation with low digestibility.

Formulation and Characterization of Losartan Loaded Chitosan Microspheres: Effect of Crosslinking Agents.

The present investigation entailed determination of effect of diverse cross-linking agents on Losartan Potassium loaded chitosan microspheres. The emulsion cross-linking method was employed to formulate the microspheres with an endeavour to achieve maximum sustained effect. The FTIR studies revealed absence of any interaction between Losartan and chitosan. The emulsion cross linking method was accomplished in three steps encompassing formation of an aqueous and oily phase, emulsification and cross-linking. A total of eighteen Losartan formulations were developed using six different cross-linkers at three varying level were screened for optimum parameters. The in vitro drug release parameters of optimum formulations (LC3, LE3, LF3, LG3, LS3 and LV3) containing citric acid, epichlorohydrin, formaldehyde, glutaraldehyde, suphuric acid and vanillin as cross-linkers were assessed to determine the sustained effect. The values of evaluated parameters including percent yield (94.67%), average particle size (51.19 µm), drug content (44.38 mg) and entrapment efficiency (88.77%) connoted LG3 as the best formulation. Additionally, the values of relative measure of skewness (β1=0.01 and γ1=0.10) and platykurtic (β2=1.26) size distribution were least for LG3 with spherical shape and smooth surface as revealed by SEM studies. The outcome of in vitro release and other characterizations of microspheres explicitly revealed glutaraldehyde as the best cross-linker amongst the cross-linkers used herewith. The maximum sustained effect (lasting over a period of 24 h) accompanied with higher MDT and t50% with lower%DE and Q14h values thus corroborated the objective of attaining sustained release of Losartan.

Efeito Biomodificador de Diferentes Agentes de Ligações Cruzadas nas Propriedades Mecânicas do Colágeno Dentinário

Objetivo: avaliar o efeito biomodificador dos agentes de ligações cruzadas nas propriedades mecânicas do colágeno dentinário. Material e Métodos: Trata-se de um estudo laboratorial in vitro, nos quais foram confeccionadas 18 barras de dentina a partir de terceiros molares humanos extraídos e livres de cárie. Os espécimes foram desmineralizados em ácido fosfórico a 10%, por 5 horas, distribuídos aleatoriamente nos grupos distintos e mantidos em suas respectivas soluções de pré-tratamento: água destilada (AD), Proantocianidina a 6,5% (PAC6,5) e Cardanol a 6,5% (CAR6,5) por períodos de 1 hora. Foram realizados os testes de flexão de três pontos para obtenção do módulo de elasticidade (ME) e modificação de massa (MM). Foram submetidos ao teste de Kolmogorov-Smirnoff seguido, do teste de ANOVA à um critério e pós teste de Tukey para a MM, e Dunns para diferença de ME (p<0,05). Resultados: Os valores obtidos no ME mostraram mudanças estatísticas notáveis em todos os grupos testados, quando comparados ao controle negativo (p<0,001), assim como na variação de massa foram encontradas diferenças estatísticas nos valores médios entre os grupos testados (p=0,012). Conclusão: o uso da PAC6,5 irá melhorar as propriedades mecânicas do colágeno

Optimization of microcapsules shell structure to preserve labile compounds: A comparison between microfluidics and conventional homogenization method

A new technique is presented to optimize the formulation of microcapsules loaded with labile compounds. Fish oil was loaded into the microcapsule core and protected with a shell composed of whey protein microgel/beet pectin complexes. The microcapsules were formed using two different methods: microfluidics and homogenization. The microcapsules were further classified into three sub-groups. The first group was the microcapsules cross-linked with laccase (MCL), the second group was the microcapsules cross-linked with divalent cationic CaCl2 salt (MCS), and the third group consisted of control microcapsules (CM), with no cross-linking. The microfluidics method enabled tracking of the effect of the shell cross-linking ability of laccase, or CaCl2, on microcapsules. It was demonstrated that MCL obtained by microfluidics are more physicochemically stable than those produced via a homogenizer. The effect of cross-linking agents on the microcapsules were more significant when the microcapsules were produced by microfluidics.

The Effect of Cross-Linking Agents and Collagen Concentrations on Properties of Collagen Scaffolds

Background: Collagen-based scaffolds are appealing products for various applications in pharmaceutics and tissue engineering and military applications like wound healing. Objectives: This study was conducted to extract acid soluble collagen protein from calf skin tissue and cross-linked it using cross-linking agents. The collagen scaffolds with different 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) / N-hydroxysuccinimide (NHS) molar ratios as cross-linking agents were investigated. Methods: The type I extracted collagen was used as a raw material for making collagen based scaffolds. Different EDC/NHS molar ratios as cross-linking agents were used. Matrix morphology and mechanical strength of the scaffolds were determined to evaluate the physicochemical properties of the collagen matrices with different cross-linker molar ratios. Furthermore collagen and cross-linked collagen were characterized using standard methods like SDS- page, FT-IR and SEM analysis. Results: The results confirmed that the extracted collagen is pure and free of any non-collagen protein contamination. Furthermore, the results showed that average pore size of the scaffolds from EDC/NHS cross-linker with molar ratio of 1:1 (I) was less than the scaffolds that were made using EDC/NHS cross-linker with molar ratio of 2:1 (II). Moreover, collagen samples that were cross-linked using 1:1 EDC/NHS molar ratios showed increased mechanical strength comparing to 2:1 EDC/NHS molar ratio. Conclusions: The applied protocol is a convenient method for extraction of collagen and obtaining pure calf skin collage type I. Furthermore the best molar ratio of EDC/NHS cross-linking agents to cross-link collagen is 1:1 for obtaining stronger collagen structure.

Effects of Cross-Linking Agents on Synthesis of Heat-Resistant Resin from Ethylene Tar

Ethylene tar (ET) was utilized as raw material, 1,4-benzenedimethanol and trioxane as crosslinking agent to prepare condensed poly-nuclear aromatic resin (COPNAR). FT-IR, 1H-NMR, TGA, elemental analysis, and improved Brown-Ladner calculation were systematically conducted for ET, COPNAR, and COPNAR/graphite composites prepared via graphite molding. The ET average molecular structure parameters were calculated using improved Brown-Ladner method, the crosslinking agent was found an important factor for the COPNAR synthesis, and the obtained COPNAR and CONPAR/graphite composites exhibited highly beneficial heat resistance.

Collagen Based Materials for Biomedical Applications: Preparation and Properties

Collagen-based materials were prepared and their properties were studied. The shape of collagen materials was as follows: thin films, hydrogels, and sponges. Microstructure and mechanical properties of films and sponges were studied. The effect of cross-linking agents and the effect of synthetic polymer on the properties of collagen materials were studied and analyzed. Collagen-based materials can be considered as potential biomaterials in tissue engineering.

In Vitro Release of Lysozyme from Gelatin Microspheres: Effect of Cross-linking Agents and Thermoreversible Gel as Suspending Medium

This study was aimed to characterize the microstructure and the performance of gelatin microspheres (GMs) cross-linked by two different cross-linkers viz. d-glucose and glutaraldehyde. New formulations were obtained, suspending the GMs in a thermoreversible Pluronic F127 (PF127) liquid-crystalline gel. Lysozyme was used as a model biomacromolecular drug to evaluate release features. Both types of cross-linked GMs were prepared by thermal gelation method. The lysozyme-loaded microspheres were characterized by scanning electron microscopy (SEM) for size distribution, shape, and surface texture. SEM revealed that both types of lysozyme-loaded GMs were spherical in shape and that the surface of glutaraldehyde cross-linked GMs was smoother than that of the glucose cross-linked GMs. The degree of cross-linking of microspheres was investigated using ATR-FTIR technique. The prepared GMs were suspended in 20% w/v aqueous PF127 gel for which the usual sol-gel transition temperature of 22 °C did not change in the presence of GMs, as indicated by rheological measurements. SAXS study of the PF127 gel confirmed the occurrence of a discrete cubic liquid-crystalline phase of the Fm3m type whose lattice parameter slightly decreased as a result of GMs addition. The in vitro release of lysozyme from both types of cross-linked GMs was successfully controlled when they were suspended in PF127 gel, thus suggesting the potential use of this new combined formulation as a drug-depot system.

Dehydration of ethyl acetate aqueous solution by pervaporation using PVA/PAN hollow fiber composite membrane

Using poly(vinyl alcohol) (PVA) as coating material, tartaric acid (Tac) and maleic anhydride (Mac) as cross-linking agents and the poly(acrylonitrile) (PAN) hollow fiber ultrafiltration membrane as support layer, the PVA/PAN composite membrane was prepared by dip-coating method used for pervaporation (PV) dehydration of ethyl acetate (EAc)/H 2O solution. The PVA/PAN composite membrane was characterized by FT-IR spectra and SEM. The effects of cross-linking agents on the swelling degree and PV performance of PVA/PAN membrane were investigated, respectively. The separation factor of PVA/PAN composite membrane increased while the permeation flux decreased with increasing the contents of cross-linking agents, and PVA/PAN membrane exhibited better PV performance when Tac/PVA mass ratio was 0.2. Furthermore, the PV performance of PVA/PAN composite membrane for EAc/H 2O solution was investigated with respect to the feed temperatures and feed water concentrations. For PVA/PAN composite membrane with Tac/PVA mass ratio of 0.2, its performance for 2 wt.% water of EAc solution at 40 °C was evaluated as follows: the separation factor and permeation flux were 7270 and 34.5 g m −2 h −1, respectively. In addition, PVA/PAN composite membrane was also used for PV dehydration of EAc/ethanol (EtOH)/H 2O ternary solution.

Effect of Crosslinking Agents on the Physico-Mechanical Characteristics of Rubber Seals Used in Hydrocarbon Media

Effect of Crosslinking Agents on the Physico-Mechanical Characteristics of Rubber Seals Used in Hydrocarbon Media

Chondroitin-6-sulphate incorporated into collagen gels for the growth of human keratinocytes: the effect of cross-linking agents and diamines

This study demonstrates the effect of the glycosaminoglycans, hyaluronic acid and chondroitin-6-sulphate (Ch6SO 4), diamines and a carbodiimide cross-linking agent on the growth of human epidermal cells on collagen gels. Ch6SO 4 incorporated into collagen gels stimulated cell growth rate, but the effect was found to be inconsistent. We found that approximately 50% of the incorporated Ch6SO 4 in the gels leached out into the growth medium after the first 3 d in culture, and this is thought to lead to the inconsistent cell growth response. In order to minimize the elution of Ch6SO 4 from the gels and thereby maximize its effect on the growth of the keratinocytes, 1–100 μg ml −1 Ch6SO 4 was added in the medium. The results showed that Ch6SO 4 at these concentrations in the medium did not stimulate the cell growth on either plain collagen gels or gels containing 20% Ch6SO 4. As an alternative strategy, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and diamines (putrescine or diaminohexane) were used to immobilize Ch6SO 4 onto the collagen gels and to cross-link the gels. The cross-linking process partially prevented the elution of Ch6SO 4 from the gels. Interestingly, only putrescine, not diaminohexane, promoted the growth of keratinocytes on the cross-linked plain collagen gels. We proposed to develop an artificial skin substitute containing putrescine as a growth factor for the human epidermal cells.

Effect of cross-linking agents on the dynamic mechanical properties of hydrogel blends of poly(acrylic acid)-poly(vinyl alcohol-vinyl acetate)

A range of hydrogels were prepared by blending aqueous solutions of poly(vinyl alcohol-vinyl acetate) with poly(acrylic acid) in various proportions. The effects of two cross-linking agents (glyoxal and glutaraldehyde) and subsequent thermal treatment on the properties of the blends are discussed. Dynamic mechanical analysis (DMA) of the xerogels indicated complete miscibility of the various blends which was evident from the appearance of a single glass transition temperature ( T g ) in the presence of either glyoxal or glutaraldehyde at all thermal treatments studied. A 50/50% wt/wt blend was found to have the highest storage modulus and was thus selected for further study. Hydrogels prepared with glutaraldehyde without subsequent thermal treatment exhibited higher storage modulus values than those prepared using glyoxal when tested isothermally at 20 °C in a water bath. A further increase in the storage modulus was observed when these hydrogels were thermally treated at 120 or 150 °C. In a non-isothermal study on the cross-linked hydrogels, no variation in storage modulus was observed. Broad peaks were observed in tan δ plots, these peaks shifting towards higher frequencies as the degree of cross-linking increased in the hydrogel.