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Fulltext Topical Nanoemulsion Hydrogel Formulated from Supercritical Fluid Extracted Palm-Pressed Fiber Oil and Virgin Coconut Oil with Antioxidant and Antibacterial Effects

Mah SH, Sundrasegaran S, Lau HLN

J Oleo Sci, 2024;73(4):489-502.
PMID: 38556283 DOI: 10.5650/jos.ess23197

Skincare industries are growing rapidly around the globe but most products are formulated using synthetic chemicals and organic solvent extracted plant extracts, thus may be hazardous to the users and incur higher cost for purification that eventually leads to phytonutrient degradation. Therefore, this study aimed to formulate a stable natural formulation with antioxidant and antimicrobial activities by using supercritical carbon dioxide (SC-CO 2 ) extracted palm-pressed fiber oil (PPFO) as an active ingredient with virgin coconut oil (VCO) as a formulation base. PPFO was extracted from fresh palm-pressed fiber (PPF) while VCO was from dried grated coconut copra using SC-CO 2 before being subjected to the analyses of physicochemical properties, phytonutrient content and biological activities including antioxidant and antimicrobial. The nanoemulgel formulations were then developed and examined for their stability through accelerated stability study for 3 months by measuring their pH, particle size, polydispersity index and zeta potential. The results showed that PPFO contained a high amount of phytonutrients, especially total carotenoid (1497 ppm) and total tocopherol and tocotrienol (2269 ppm) contents. The newly developed nanoemulgels maintained their particles in nano size and showed good stability with high negative zeta potentials. Sample nanoemulgel formulated with 3% PPFO diluted in VCO as effective concentration showed significantly stronger antioxidant activity than the control which was formulated from 3% tocopheryl acetate diluted in mineral oil, towards DPPH and ABTS radicals, with IC 50 values of 67.41 and 44.28 µL/mL, respectively. For the antibacterial activities, the sample nanoemulgel was found to inhibit Gram positive bacteria S. aureus and S. epidermidis growth but not the Gram negative strain E. coli. Overall, this study revealed the potential of SF-extracted PPFO as an active ingredient in the antioxidant topical formulations thus future study on in vitro skin cell models is highly recommended for validation.

Matched MeSH terms: Hydrogels*
Use of bioelectric dressings for patients with hard-to-heal wounds: a case report

Nair HK, Yan TD

J Wound Care, 2023 Oct 01;32(Sup10a):S8-S14.
PMID: 37830843 DOI: 10.12968/jowc.2023.32.Sup10a.S8

There are many types of dressings available for the management of hard-to-heal (chronic) wounds. This case report illustrates the efficacy of bioelectric dressings in healing hard-to-heal wounds in five patients. Of the patients, four had diabetic foot ulcers (DFUs) and one had a surgical site infection. Wounds were examined using the TIMES concept and debridement was carried out if needed. Amorphous hydrogel was used as conduction fluid before the application of the bioelectric wound dressings. The wound was covered with foam dressing and crepe bandage. In this case report, among all five wounds, one wound healed completely while the other four reduced in size, with the presence of more granulation and re-epithelialisation. In this case report, bioelectric wound dressings were effective in managing infection and promoting wound healing.

Matched MeSH terms: Hydrogels
Fulltext Unravelling the dynamics of genotype and environment interactions on chilli (Capsicum annuum L.) yield-related attributes in soilless planting systems

Sahmat SS, Rafii MY, Oladosu Y, Jusoh M, Hakiman M, Mohidin H

Sci Rep, 2024 Jan 19;14(1):1698.
PMID: 38242885 DOI: 10.1038/s41598-023-50381-0

Evaluation of genotypes to identify high-yielding and stable varieties is crucial for chilli production sustainability and food security. These analyses are essential, particularly when the breeding program aims to select lines with great adaptability and stability. Thirty chilli genotypes were evaluated for yield stability under four soilless planting systems viz; fertigation, HydroStock (commercial hydrogel), BioHydrogel (biodegradable hydrogel), and hydroponic to study the influence of genotype by environment interaction. The research used a split-plot randomized complete block design (RCBD) with two cropping cycles and five replications. The GGE biplot analysis was employed to assess the mean versus stability perspective in explaining the variation in genotypic and genotype-by-environment effects on the yield-related attributes for yield per plant, fruit number, fruit length, and width. Stability analysis denoted genotypes G26 and G30 as the most stable for yield per plant, while G16, G22, and G30 were stable for the number of fruits per plant. Among the four planting systems evaluated, HydroStock and BioHydrogel outperformed the others in yield per plant, demonstrating the highest level of informativeness or discrimination. These findings offer critical insights for future crop breeding programs and the optimization of agricultural practices.

Matched MeSH terms: Hydrogels
Chemically crosslinked hydrogel and its driving force towards superabsorbent behaviour

Salleh KM, Zakaria S, Sajab MS, Gan S, Chia CH, Jaafar SNS, et al.

Int J Biol Macromol, 2018 Oct 15;118(Pt B):1422-1430.
PMID: 29964115 DOI: 10.1016/j.ijbiomac.2018.06.159

Dissolved oil palm empty fruit bunch (EFB) cellulose in NaOH/urea solvent was mixed with sodium carboxymethylcellulose (NaCMC) to form a green regenerated superabsorbent hydrogel. The effect of concentration of epichlorohydrin (ECH) as the crosslinker on the formation, physical, and chemical properties of hydrogel was studied. Rapid formation and higher gel content of hydrogel were observed at 10% concentration of ECH. The superabsorbent hydrogel was successfully fabricated in this study with the swelling ability >100,000%. Hydrogel with higher concentration of ECH showed opposite trend by having higher superabsorbent property than that of lower concentration. The covalent bond of COC was observed with Attenuated total reflectance fourier transform infrared (ATR-FT-IR) spectroscopy to confirm the occurrence of crosslinking. The physical and chemical properties of hydrogel were affected by swelling phenomenon. Hydrogel with higher degree of swelling exhibited lower moisture retention and higher transparency. Moreover, the weight of the superabsorbent hydrogel increased with the decrement of pH value of external media (distilled water). This study provided substantial information on the effect of different percentage of ECH as crosslinker on hydrogel basic properties. Furthermore, this study affords correlation of many essential driving forces that affected hydrogel superabsorbent property.

Matched MeSH terms: Hydrogels/chemistry*
Influence of a nonionic surfactant on curcumin delivery of nanocellulose reinforced chitosan hydrogel

Sampath Udeni Gunathilake TM, Ching YC, Chuah CH, Illias HA, Ching KY, Singh R, et al.

Int J Biol Macromol, 2018 Oct 15;118(Pt A):1055-1064.
PMID: 30001596 DOI: 10.1016/j.ijbiomac.2018.06.147

Nanocellulose reinforced chitosan hydrogel was synthesized using chemical crosslinking method for the delivery of curcumin which is a poorly water-soluble drug. Curcumin extracted from the dried rhizomes of Curcuma longa was incorporated to the hydrogel via in situ loading method. A nonionic surfactant (Tween 20) was incorporated into the hydrogel to improve the solubility of curcumin. After the gas foaming process, hydrogel showed large interconnected pore structures. The release studies in gastric medium showed that the cumulative release of curcumin increased from 0.21% ± 0.02% to 54.85% ± 0.77% with the increasing of Tween 20 concentration from 0% to 30% (w/v) after 7.5 h. However, the entrapment efficiency percentage decreased with the addition of Tween 20. The gas foamed hydrogel showed higher initial burst release within the first 120 min compared to hydrogel formed at atmospheric condition. The solubility of curcumin would increase to 3.014 ± 0.041 mg/mL when the Tween 20 concentration increased to 3.2% (w/v) in simulated gastric medium. UV-visible spectra revealed that the drug retained its chemical activity after in vitro release. From these findings, it is believed that the nonionic surfactant incorporated chitosan/nanocellulose hydrogel can provide a platform to overcome current problems associated with curcumin delivery.

Matched MeSH terms: Hydrogels/chemistry*
Recent Development in the Fabrication of Collagen Scaffolds for Tissue Engineering Applications: A Review

Busra MFM, Lokanathan Y

Curr Pharm Biotechnol, 2019;20(12):992-1003.
PMID: 31364511 DOI: 10.2174/1389201020666190731121016

Tissue engineering focuses on developing biological substitutes to restore, maintain or improve tissue functions. The three main components of its application are scaffold, cell and growthstimulating signals. Scaffolds composed of biomaterials mainly function as the structural support for ex vivo cells to attach and proliferate. They also provide physical, mechanical and biochemical cues for the differentiation of cells before transferring to the in vivo site. Collagen has been long used in various clinical applications, including drug delivery. The wide usage of collagen in the clinical field can be attributed to its abundance in nature, biocompatibility, low antigenicity and biodegradability. In addition, the high tensile strength and fibril-forming ability of collagen enable its fabrication into various forms, such as sheet/membrane, sponge, hydrogel, beads, nanofibre and nanoparticle, and as a coating material. The wide option of fabrication technology together with the excellent biological and physicochemical characteristics of collagen has stimulated the use of collagen scaffolds in various tissue engineering applications. This review describes the fabrication methods used to produce various forms of scaffolds used in tissue engineering applications.

Matched MeSH terms: Hydrogels/chemistry
Fulltext Solvent Dependence of the Rheological Properties in Hydrogel Magnetorheological Plastomer

Hapipi NM, Mazlan SA, Ubaidillah U, Abdul Aziz SA, Ahmad Khairi MH, Nordin NA, et al.

Int J Mol Sci, 2020 Mar 05;21(5).
PMID: 32151055 DOI: 10.3390/ijms21051793

Chemically crosslinked hydrogel magnetorheological (MR) plastomer (MRP) embedded with carbonyl iron particles (CIPs) exhibits excellent magnetic performance (MR effect) in the presence of external stimuli especially magnetic field. However, oxidation and desiccation in hydrogel MRP due to a large amount of water content as a dispersing phase would limit its usage for long-term applications, especially in industrial engineering. In this study, different solvents such as dimethyl sulfoxide (DMSO) are also used to prepare polyvinyl alcohol (PVA) hydrogel MRP. Thus, to understand the dynamic viscoelastic properties of hydrogel MRP, three different samples with different solvents: water, DMSO, and their binary mixtures (DMSO/water) were prepared and systematically carried out using the oscillatory shear. The outcomes demonstrate that the PVA hydrogel MRP prepared from precursor gel with water shows the highest MR effect of 15,544% among the PVA hydrogel MRPs. However, the samples exhibit less stability and tend to oxidise after a month. Meanwhile, the samples with binary mixtures (DMSO/water) show an acceptable MR effect of 11,024% with good stability and no CIPs oxidation. Otherwise, the sample with DMSO has the lowest MR effect of 7049% and less stable compared to the binary solvent samples. This confirms that the utilisation of DMSO as a new solvent affects the rheological properties and stability of the samples.

Matched MeSH terms: Hydrogels/chemistry*
Fulltext Highly porous regenerated cellulose hydrogel and aerogel prepared from hydrothermal synthesized cellulose carbamate

Gan S, Zakaria S, Chia CH, Chen RS, Ellis AV, Kaco H

PLoS One, 2017;12(3):e0173743.
PMID: 28296977 DOI: 10.1371/journal.pone.0173743

Here, a stable derivative of cellulose, called cellulose carbamate (CC), was produced from Kenaf (Hibiscus cannabinus) core pulp (KCP) and urea with the aid of a hydrothermal method. Further investigation was carried out for the amount of nitrogen yielded in CC as different urea concentrations were applied to react with cellulose. The effect of nitrogen concentration of CC on its solubility in a urea-alkaline system was also studied. Regenerated cellulose products (hydrogels and aerogels) were fabricated through the rapid dissolution of CC in a urea-alkaline system. The morphology of the regenerated cellulose products was viewed under Field emission scanning electron microscope (FESEM). The transformation of allomorphs in regenerated cellulose products was examined by X-ray diffraction (XRD). The transparency of regenerated cellulose products was determined by Ultraviolet-visible (UV-Vis) spectrophotometer. The degree of swelling (DS) of regenerated cellulose products was also evaluated. This investigation provides a simple and efficient procedure of CC determination which is useful in producing regenerated CC products.

Matched MeSH terms: Hydrogels/chemistry*
Topological characterization of a bacterial cellulose-acrylic acid polymeric matrix

Halib N, Mohd Amin MC, Ahmad I, Abrami M, Fiorentino S, Farra R, et al.

Eur J Pharm Sci, 2014 Oct 1;62:326-33.
PMID: 24932712 DOI: 10.1016/j.ejps.2014.06.004

This paper focuses on the micro- and nano-topological organization of a hydrogel, constituted by a mixture of bacterial cellulose and acrylic acid, and intended for biomedical applications. The presence of acrylic acid promotes the formation of two interpenetrated continuous phases: the primary "pores phase" (PP) containing only water and the secondary "polymeric network phase" (PNP) constituted by the polymeric network swollen by the water. Low field Nuclear Magnetic Resonance (LF NMR), rheology, Scanning Electron Microscopy (SEM) and release tests were used to determine the characteristics of the two phases. In particular, we found that this system is a strong hydrogel constituted by 81% (v/v) of PP phase the remaining part being occupied by the PNP phase. Pores diameters span in the range 10-100 μm, the majority of them (85%) falling in the range 30-90 μm. The high PP phase tortuosity indicates that big pores are not directly connected to each other, but their connection is realized by a series of interconnected small pores that rend the drug path tortuous. The PNP is characterized by a polymer volume fraction around 0.73 while mesh size is around 3 nm. The theoretical interpretation of the experimental data coming from the techniques panel adopted, yielded to the micro- and nano-organization of our hydrogel.

Matched MeSH terms: Hydrogels/chemistry*
Recent advances in the role of supramolecular hydrogels in drug delivery

Amin MC, Ahmad N, Pandey M, Abeer MM, Mohamad N

Expert Opin Drug Deliv, 2015 Jul;12(7):1149-61.
PMID: 25547588 DOI: 10.1517/17425247.2015.997707

Supramolecular hydrogels, formed by noncovalent crosslinking of polymeric chains in water, constitute an interesting class of materials that can be developed specifically for drug delivery and biomedical applications. The biocompatibility, stimuli responsiveness to various external factors, and powerful functionalization capacity of these polymeric networks make them attractive candidates for novel advanced dosage form design.

Matched MeSH terms: Hydrogels*
Classification, processing and application of hydrogels: A review

Ullah F, Othman MB, Javed F, Ahmad Z, Md Akil H

Mater Sci Eng C Mater Biol Appl, 2015 Dec 1;57:414-33.
PMID: 26354282 DOI: 10.1016/j.msec.2015.07.053

This article aims to review the literature concerning the choice of selectivity for hydrogels based on classification, application and processing. Super porous hydrogels (SPHs) and superabsorbent polymers (SAPs) represent an innovative category of recent generation highlighted as an ideal mould system for the study of solution-dependent phenomena. Hydrogels, also termed as smart and/or hungry networks, are currently subject of considerable scientific research due to their potential in hi-tech applications in the biomedical, pharmaceutical, biotechnology, bioseparation, biosensor, agriculture, oil recovery and cosmetics fields. Smart hydrogels display a significant physiochemical change in response to small changes in the surroundings. However, such changes are reversible; therefore, the hydrogels are capable of returning to its initial state after a reaction as soon as the trigger is removed.

Matched MeSH terms: Hydrogels/chemistry*
Carboxymethyl cellulose/sodium alginate beads incorporated with calcium carbonate nanoparticles and bentonite for phosphate recovery

Fu J, Yap JX, Leo CP, Chang CK

Int J Biol Macromol, 2023 Apr 15;234:123642.
PMID: 36791941 DOI: 10.1016/j.ijbiomac.2023.123642

Although anionic polyelectrolyte hydrogel beads offer attractive adsorption of cationic dyes, phosphate adsorption is limited by electrostatic interactions. In this work, carboxymethyl cellulose (CMC)/sodium alginate (SA) hydrogel beads were modified with calcium carbonate (CaCO3) and/or bentonite (Be). The compatibility between CaCO3 and Be was proven by the homogeneous surface, as shown in the scanning electron microscopic images. Fourier-transform infrared and X-ray diffraction spectra further confirmed the existence of inorganic filler in the hydrogel beads. Although CMC/SA/Be/CaCO3 hydrogel beads attained the highest methylene blue and phosphate adsorption capacities (142.15 MB mg/g, 90.31 P mg/g), phosphate adsorption was significantly improved once CaCO3 nanoparticles were incorporated into CMC/SA/CaCO3 hydrogel beads. The kinetics of MB adsorption by CMC/SA hydrogel beads with or without inorganic fillers could be described by the pseudo-second-order model under chemical interactions. The phosphate adsorption by CMC/SA/Be/CaCO3 hydrogel beads could be explained by the Elovich model due to heterogeneous properties. The incorporation of Be and CaCO3 also improved the phosphate adsorption through chemical interaction since Langmuir isotherm fitted the phosphate adsorption by CMC/SA/Be/CaCO3 hydrogel beads. Unlike MB adsorption, the reusability of these hydrogel beads in phosphate adsorption reduced slightly after 5 cycles.

Matched MeSH terms: Hydrogels/chemistry
Nigella sativa Oil-loaded Ethanolic Vesicular Gel for Imiquimod-induced Plaque Psoriasis: Physicochemical Characterization, Rheological Studies, and In vivo Efficacy

Vihal S, Pundir S, Rathore C, Ranjan Lal U, Gupta G, Kumar Singh S, et al.

Curr Drug Deliv, 2025;22(1):80-91.
PMID: 38956909 DOI: 10.2174/0115672018246645231019131748

BACKGROUND: The therapeutic effect of NS oil in mild to moderate psoriasis is limited owing to low play load of thymoquinone (<15 %w/w), irritation, dripping, low viscosity and thus, less contact time on the lesions.
AIMS: This study aimed at developing and characterizing the ethanolic vesicular hydrogel system of Nigella sativa (NS) oil (NS EV hydrogel) for the enhancement of anti-psoriatic activity.
OBJECTIVE: The objective of this study was to develop NS EV hydrogel and evaluate its anti-psoriatic activity.
METHODS: The identification and quantification of TQ content in different NS seed extracts and marketed oil were measured by an HPTLC method using n-hexane and ethyl acetate as solvent systems. Preparation of ethanolic vesicles (EVs) was performed by solvent injection method, while its antipsoriatic activity was evaluated employing an Imiquad (IMQ)-induced plaque psoriasis animal model.
RESULTS: A compact HPTLC band was obtained for TQ at an Rf value of 0.651. The calibration plot was linear in the range of 1-10 μg/spot, and the correlation coefficient of 0.990 was indicative of good linear dependence of peak area on concentration. From the different NS sources, the high TQ content was obtained in the marketed cold press oil, i.e., 1.45±0.08 mg/ml. Out of various NS oilloaded EVs, the F6 formulation revealed the smallest particle size (278.1 nm), with log-normal size distribution (0.459) and adequate entrapment efficiency. A non-uniform shape was observed in the transmission electron microscopy. The viscosity of F6 formulation hydrogel was 32.34 (Pa·s), which exhibited plastic behavior. In vivo, efficacy studies demonstrated decreased inflammation of the epidermis and dermis and a marked decrease in the levels of IL-17 by NS EV hydrogel compared to plain NS oil and standard drugs (Betamethasone and Dr. JRK Psorolin Oil).
CONCLUSION: It may be concluded from the findings that NS-loaded EV gel was as good as betamethasone cream but more efficacious than the other treatments.

Matched MeSH terms: Hydrogels/chemistry
Fulltext Supramolecular Nested Microbeads as Building Blocks for Macroscopic Self-Healing Scaffolds

Yu Z, Liu J, Tan CSY, Scherman OA, Abell C

Angew Chem Int Ed Engl, 2018 03 12;57(12):3079-3083.
PMID: 29377541 DOI: 10.1002/anie.201711522

The ability to construct self-healing scaffolds that are injectable and capable of forming a designed morphology offers the possibility to engineer sustainable materials. Herein, we introduce supramolecular nested microbeads that can be used as building blocks to construct macroscopic self-healing scaffolds. The core-shell microbeads remain in an "inert" state owing to the isolation of a pair of complementary polymers in a form that can be stored as an aqueous suspension. An annealing process after injection effectively induces the re-construction of the microbead units, leading to supramolecular gelation in a preconfigured shape. The resulting macroscopic scaffold is dynamically stable, displaying self-recovery in a self-healing electronic conductor. This strategy of using the supramolecular assembled nested microbeads as building blocks represents an alternative to injectable hydrogel systems, and shows promise in the field of structural biomaterials and flexible electronics.

Matched MeSH terms: Hydrogels
Fulltext Nanogels linked with chitosan: a perspective

Chellappan DK, Panneerselvam J, Madheswaran T, Chellian J, Ambar Jeet Singh BJ, Jia Yee N, et al.

Minerva Med, 2018 06;109(3):254-255.
PMID: 29849021 DOI: 10.23736/S0026-4806.18.05462-9
Matched MeSH terms: Hydrogels
Herbal hydrogel-based encapsulated Enterococcus faecium ABRIINW.N7 improves the resistance of red hybrid tilapia against Streptococcus iniae

Kahieshesfandiari M, Nami Y, Lornezhad G, Kiani A, Javanmard A, Jaymand M, et al.

J Appl Microbiol, 2021 Nov;131(5):2516-2527.
PMID: 33817937 DOI: 10.1111/jam.15098

AIMS: The streptococcal disease has been associated with serious mortality and significant global economic loss in the tilapia farming industry. The overall goal of this work was to test herbal hydrogels based on encapsulated Enterococcus faecium ABRIINW.N7 for potential probiotic anti-microbial activity against Streptococcus iniae in red hybrid tilapia.
METHODS AND RESULTS: Abnormal behaviour, clinical signs, postinjection survival and histopathology (kidney, liver, eye and brain) were measured. Cumulative mortality of CON+ , free cells, ALG and treatments (F1-F7) was 30, 24, 22, 19, 17, 17, 16, 14, 14 and 12 out of 30 fish and the survival rates for E. faecium ABRIINW.N7 microencapsulated in an alginate-BS blend with 0·5, 1, 1·5, 2, 2·5 and 3% fenugreek were 43, 43, 47, 53, 53 and 60%, respectively. After the incorporation of fenugreek with the alginate-BS blend, there was an 8-21% increase in probiotic cell viability. Furthermore, the survival rate for the alginate-BS blend with 2·5 and 3% fenugreek (F6 and F7) was significantly (P ≤ 0·05) higher than other blends. The highest encapsulation efficiency, viability in gastrointestinal conditions and during storage time and excellent antipathogenicity against S. iniae were observed in alginate-BS +3% fenugreek formulation (F7).
CONCLUSIONS: It is recommended that probiotic strains like E. faecium ABRIINW.N7 in combination with local herbal gums, such as BS and fenugreek plus alginate, can be used as a suitable scaffold and an ideal matrix for the encapsulation of probiotics.
SIGNIFICANCE AND IMPACT OF THE STUDY: This study proposes models connecting process parameters, matrix structure and functionality.

Matched MeSH terms: Hydrogels
Fulltext The Efficacy of Gelam Honey Dressing towards Excisional Wound Healing

Tan MK, Hasan Adli DS, Tumiran MA, Abdulla MA, Yusoff KM

Evid Based Complement Alternat Med, 2012;2012:805932.
PMID: 22536292 DOI: 10.1155/2012/805932

Honey is one of the oldest substances used in wound management. Efficacy of Gelam honey in wound healing was evaluated in this paper. Sprague-Dawley rats were randomly divided into four groups of 24 rats each (untreated group, saline group, Intrasite Gel group, and Gelam honey group) with 2 cm by 2 cm full thickness, excisional wound created on neck area. Wounds were dressed topically according to groups. Rats were sacrificed on days 1, 5, 10, and 15 of treatments. Wounds were then processed for macroscopic and histological observations. Gelam-honey-dressed wounds healed earlier (day 13) than untreated and saline treated groups, as did wounds treated with Intrasite Gel. Honey-treated wounds exhibited less scab and only thin scar formations. Histological features demonstrated positive effects of Gelam honey on the wounds. This paper showed that Gelam honey dressing on excisional wound accelerated the process of wound healing.

Matched MeSH terms: Hydrogels
Synthesis and evaluation on pH- and temperature-responsive chitosan-p(MAA-co-NIPAM) hydrogels

Rasib SZM, Ahmad Z, Khan A, Akil HM, Othman MBH, Hamid ZAA, et al.

Int J Biol Macromol, 2018 Mar;108:367-375.
PMID: 29222015 DOI: 10.1016/j.ijbiomac.2017.12.021

In this study, chitosan-poly(methacrylic acid-co-N-isopropylacrylamide) [chitosan-p(MAA-co-NIPAM)] hydrogels were synthesized by emulsion polymerization. In order to be used as a carrier for drug delivery systems, the hydrogels had to be biocompatible, biodegradable and multi-responsive. The polymerization was performed by copolymerize MAA and NIPAM with chitosan polymer to produce a chitosan-based hydrogel. Due to instability during synthesis and complexity of components to produce the hydrogel, further study at different times of reaction is important to observe the synthesis process, the effect of end product on swelling behaviour and the most important is to find the best way to control the hydrogel synthesis in order to have an optimal swelling behaviour for drug release application. Studied by using Fourier transform infra-red (FTIR) spectroscopy found that, the synthesized was successfully produced stable chitosan-based hydrogel with PNIPAM continuously covered the outer surface of hydrogel which influenced much on the stability during synthesis. The chitosan and PMAA increased the zeta potential of the hydrogel and the chitosan capable to control shrinkage above human body temperature. The chitosan-p(MAA-co-NIPAM) hydrogels also responses to pH and temperature thus improved the ability to performance as a drug carrier.

Matched MeSH terms: Hydrogels/chemical synthesis; Hydrogels/chemistry*
Synthesis and functionalization of chitosan built hydrogel with induced hydrophilicity for extended release of sparingly soluble drugs

Ullah F, Javed F, Othman MBH, Khan A, Gul R, Ahmad Z, et al.

J Biomater Sci Polym Ed, 2018 03;29(4):376-396.
PMID: 29285989 DOI: 10.1080/09205063.2017.1421347

Addressing the functional biomaterials as next-generation therapeutics, chitosan and alginic acid were copolymerized in the form of chemically crosslinked interpenetrating networks (IPNs). The native hydrogel was functionalized via carbodiimide (EDC), catalyzed coupling of soft ligand (1,2-Ethylenediamine) and hard ligand (4-aminophenol) to replace -OH groups in alginic acid units for extended hydrogel- interfaces with the aqueous and sparingly soluble drug solutions. The chemical structure, Lower solution critical temperature (LCST ≈ 37.88 °C), particle size (Zh,app ≈ 150-200 nm), grain size (160-360 nm), surface roughness (85-250 nm), conductivity (37-74 mv) and zeta potential (16-32 mv) of native and functionalized hydrogel were investigated by using FT-IR, solid state-13C-NMR, TGA, DSC, FESEM, AFM and dynamic light scattering (DLS) measurements. The effective swelling, drug loading (47-78%) and drug release (53-86%) profiles were adjusted based on selective functionalization of hydrophobic IPNs due to electrostatic complexation and extended interactions of hydrophilic ligands with the aqueous and drug solutions. Drug release from the hydrogel matrices with diffusion coefficient n ≈ 0.7 was established by Non- Fickian diffusion mechanism. In vitro degradation trials of the hydrogel with a 20% loss of wet mass in simulated gastric fluid (SGF) and 38% loss of wet mass in simulated intestinal fluid (SIF), were investigated for 400 h through bulk erosion. Consequently, a slower rate of drug loading and release was observed for native hydrogel, due to stronger H-bonding, interlocking and entanglement within the IPNs, which was finely tuned and extended by the induced hydrophilic and functional ligands. In the light of induced hydrophilicity, such functional hydrogel could be highly attractive for extended release of sparingly soluble drugs.

Matched MeSH terms: Hydrogels/chemical synthesis; Hydrogels/chemistry*
Controlled release studies through chitosan-based hydrogel synthesized at different polymerization stages

Md Rasib SZ, Md Akil H, Khan A, Abdul Hamid ZA

Int J Biol Macromol, 2019 May 01;128:531-536.
PMID: 30708001 DOI: 10.1016/j.ijbiomac.2019.01.190

An earlier study showed that the behaviour of chitosan-poly(methacrylic acid‑co‑N‑isopropylacrylamide) [chitosan‑p(MAA‑co‑NIPAM)] hydrogels synthesized at different reaction times are affected with regard to their pH and temperature sensitivities. The study was continued in this paper to identify the effects of different reaction times on the degradation, efficiency of rifampicin (Rif) loading and the Rif release profile under two different pH conditions (acidic and basic). The results that were obtained showed that the hydrogel had a faster degradation rate in the acidic condition than in the basic condition, where there was a loss of approximately 50% and 20%, respectively in its original weight within two weeks. The Rif loading efficiency was within 50% and the drug release was controlled by characteristics that were developed beyond the polymerization stages of the synthesis. Therefore, the reaction time for the synthesis of the hydrogel can be considered as a way to control the behaviour of the hydrogel as well as to modify the drug release profile in the chitosan‑p(MAA‑co‑NIPAM) hydrogel.

Matched MeSH terms: Hydrogels/chemical synthesis*; Hydrogels/chemistry*

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