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Fulltext Protein and microbial determinations on worn contact lenses cleaned conventionally using the Lens2® automatic lens cleaner

Haliza Abdul Mutalib, Ahmad Rohi Ghazali, Noor Suhailah Ali

Jurnal Sains Kesihatan Malaysia, 2008;6(1):11-21.
MyJurnal

The accumulation of tear film proteins as well as microbes colonization onto worn contact lenses can be eliminated conventionally by mechanical rubbing during the cleaning process. Lens2® functions in rotation manner to loosen the deposits on the contact lens and has antimicrobial coating to keep lenses away from contamination. The objective of this study was to determine the efficiency of Lens2® to remove deposited protein and reduce microbial contamination compared to conventional method. Twenty-eight subjects each wore a pair of contact lens FDA Group 1 (Polymacon, SoftLens® 38, Bausch & Lomb) for one month and cleaned them using multipurpose solution (COMPLETE® MoisturePLUSTM, Advanced Medical Optics) separately using two different methods. The right lens was cleaned conventionally while the left lens were cleaned using the Lens2®. The control group of thirteen subjects each wore a pair of contact lens for the same period and cleaned both conventionally. These lenses and its cases were then analyzed for protein deposition using Bichinchoninic Acid Assay (BCA) Kit (Sigma, USA) in 96-well plate. Microbial contamination was determined by culturing the samples on nutrient agar for bacteria and fungi and non-nutrient agar for amoeba isolation. The mean of total protein on control lenses (17.014 ± 13.246 µg/mL) was not significantly different from those on the Lens2® (21.623 ± 19.127 µg/mL). There were also low growth numbers of amoeba in each group of samples. Interestingly, there were no growths of amoeba from all Lens2® samples collected. There was also low growth numbers of bacteria in each sample group whereby Lens2® had the lowest growth of bacteria. No growth of fungi was obtained from all samples. The automatic lens cleaner, Lens2® was found to be as efficient as the conventional cleaning method. However, the Lens2® has additional advantage because of its antimicrobial material and need shorter time in the cleaning process as well as easy and effective.

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
Novel functional antimicrobial and biocompatible arabinoxylan/guar gum hydrogel for skin wound dressing applications

Khan MUA, Raza MA, Razak SIA, Abdul Kadir MR, Haider A, Shah SA, et al.

J Tissue Eng Regen Med, 2020 10;14(10):1488-1501.
PMID: 32761978 DOI: 10.1002/term.3115

It is a challenging task to develop active biomacromolecular wound dressing materials that are biocompatible and possesses antibacterial properties against the bacterial strains that cause severe skin disease. This work is focused on the preparation of a biocompatible and degradable hydrogel for wound dressing application using arabinoxylan (ARX) and guar gum (GG) natural polymers. Fourier transform infrared spectroscopy (FT-IR) confirmed that both ARX and GG interacted well with each other, and their interactions further increased with the addition of crosslinker tetraethyl orthosilicate. Scanning electron microscope (SEM) micrographs showed uniform porous morphologies of the hydrogels. The porous morphologies and uniform interconnected pores are attributed to the increased crosslinking of the hydrogel. Elastic modulus, tensile strength, and fracture strain of the hydrogels significantly improved (from ATG-1 to ATG-4) with crosslinking. Degradability tests showed that hydrogels lost maximum weight in 7 days. All the samples showed variation in swelling with pH. Maximum swelling was observed at pH 7. The hydrogel samples showed good antibacterial activity against Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) in PBS, good drug release profile (92% drug release), and nontoxic cellular behavior. The cells not only retained their cylindrical morphologies onto the hydrogel but were also performing their normal activities. It is, therefore, believed that as-developed hydrogel could be a potential material for wound dressing application.

Matched MeSH terms: Hydrogels/pharmacology*; Hydrogels/chemistry
Phomopsidione-Loaded Chitosan Polyethylene Glycol (PEG) Nanocomposite Dressing for Pressure Ulcers

Chin IBI, Yenn TW, Ring LC, Lazim Y, Tan WN, Rashid SA, et al.

J Pharm Sci, 2020 09;109(9):2884-2890.
PMID: 32534882 DOI: 10.1016/j.xphs.2020.06.005

Pressure ulcers are commonly associated with microbial infections on the wounds which require an effective wound dressing for treatment. Thus far, the available silver dressing has shown tremendous result, however, it may cause argyria and complicate the internal organ function. Hence, our study aims to develop and characterize phomopsidione-loaded chitosan-polyethylene glycol nanocomposite hydrogel (C/PEG/Ph) as an antimicrobial dressing. Physically, the C/PEG/Ph hydrogel demonstrated a uniform light blue color, soft, flexible, and elastic, with no aggregation form. The evaluation via Fourier Transform Infrared (FTIR) exposed the C/PEG/Ph hydrogel has a notable shift towards lower frequency at 1600 and 1554 cm-1. For drug release test, the phomopsidione attained plateau at 24 h, with a total release of 67.9 ± 6.4% from the C/PEG/Ph hydrogel. There was a null burst release effect discovered throughout the experimental period. The C/PEG/Ph hydrogel showed significant results against all 4 Gram-negative bacteria and 1 yeast, with 99.99-100% reduction of microbial growth. The findings revealed that the C/PEG/Ph hydrogel can potentially act as an antimicrobial dressing for pressure ulcers.

Matched MeSH terms: Hydrogels
Development and physical characterization of polymer-fish oil bigel (hydrogel/oleogel) system as a transdermal drug delivery vehicle

Rehman K, Mohd Amin MC, Zulfakar MH

J Oleo Sci, 2014;63(10):961-70.
PMID: 25252741

Polymer-Fish oil bigel (hydrogel/oleogel colloidal mixture) was developed by using fish oil and natural (sodium alginate) and synthetic (hydroxypropyl methylcellulose) polymer for pharmaceutical purposes. The bigels were closely monitored and thermal, rheological and mechanical properties were compared with the conventional hydrogels for their potential use as an effective transdermal drug delivery vehicle. Stability of the fish oil fatty acids (especially eicosapentanoic acid, EPA and docosahexanoic acid, DHA) was determined by gas chromatography and the drug content (imiquimod) was assessed with liquid chromatography. Furthermore, in vitro permeation study was conducted to determine the capability of the fish oil-bigels as transdermal drug delivery vehicle. The bigels showed pseudoplastic rheological features, with excellent mechanical properties (adhesiveness, peak stress and hardness), which indicated their excellent spreadability for application on the skin. Bigels prepared with mixture of sodium alginate and fish oil (SB1 and SB2), and the bigels prepared with the mixture of hydroxypropyl methylcellulose and fish oil (HB1-HB3) showed high cumulative permeation and drug flux compared to hydrogels. Addition of fish oil proved to be beneficial in increasing the drug permeation and the results were statistically significant (p < 0.05, one-way Anova, SPSS 20.0). Thus, it can be concluded that bigel formulations could be used as an effective topical and transdermal drug delivery vehicle for pharmaceutical purposes.

Matched MeSH terms: Hydrogels/chemical synthesis*; Hydrogels/pharmacokinetics*; Hydrogels/chemistry
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*
Swelling behaviour and controlled drug release from cross-linked κ-carrageenan/NaCMC hydrogel by diffusion mechanism

Hezaveh H, Muhamad II, Noshadi I, Shu Fen L, Ngadi N

J Microencapsul, 2012;29(4):368-79.
PMID: 22309480 DOI: 10.3109/02652048.2011.651501

We studied a model system of controlled drug release using beta-carotene and κ-carrageenan/NaCMC hydrogel as a drug and a device, respectively. Different concentrations of genipin were added to crosslink the beta-carotene loaded beads by using the dripping method. Results have shown that the cross-linked beads possess lower swelling ability in all pH conditions (pH 1.2 and 7.4), and swelling ratio decreases with increasing genipin concentration. Microstructure study shows that cross-linking has enhanced the stability and structure of the beads network. Determination of diffusion coefficient for the release of encapsulated beta-carotene indicates less diffusivity when beads are cross-linked. Swelling models using adaptive neuro fuzzy show that using genipin as a cross-linker in the kC/NaCMC hydrogels affects the transport mechanism. The model shows very good agreement with the experimental data that indicates that applying ANFIS modelling is an accurate, rapid and simple way to model in such a case for controlled release applications.

Matched MeSH terms: Hydrogels
Characterisation and in vitro antimicrobial activity of biosynthetic silver-loaded bacterial cellulose hydrogels

Gupta A, Low WL, Radecka I, Britland ST, Mohd Amin MC, Martin C

J Microencapsul, 2016 Dec;33(8):725-734.
PMID: 27781557 DOI: 10.1080/02652048.2016.1253796

Wounds that remain in the inflammatory phase for a prolonged period of time are likely to be colonised and infected by a range of commensal and pathogenic microorganisms. Treatment associated with these types of wounds mainly focuses on controlling infection and providing an optimum environment capable of facilitating re-epithelialisation, thus promoting wound healing. Hydrogels have attracted vast interest as moist wound-responsive dressing materials. In the current study, biosynthetic bacterial cellulose hydrogels synthesised by Gluconacetobacter xylinus and subsequently loaded with silver were characterised and investigated for their antimicrobial activity against two representative wound infecting pathogens, namely S. aureus and P. aeruginosa. Silver nitrate and silver zeolite provided the source of silver and loading parameters were optimised based on experimental findings. The results indicate that both AgNO3 and AgZ loaded biosynthetic hydrogels possess antimicrobial activity (p

Matched MeSH terms: Hydrogels/chemistry
pH dependent poly[2-(methacryloyloxyethyl)trimetylammonium chloride-co-methacrylic acid]hydrogels for enhanced targeted delivery of 5-fluorouracil in colon cancer cells

Mishra RK, Ramasamy K, Ahmad NA, Eshak Z, Majeed AB

J Mater Sci Mater Med, 2014 Apr;25(4):999-1012.
PMID: 24398912 DOI: 10.1007/s10856-013-5132-x

Stimuli responsive hydrogels have shown enormous potential as a carrier for targeted drug delivery. In this study we have developed novel pH responsive hydrogels for the delivery of 5-fluorouracil (5-FU) in order to alleviate its antitumor activity while reducing its toxicity. We used 2-(methacryloyloxyethyl) trimetylammonium chloride a positively charged monomer and methacrylic acid for fabricating the pH responsive hydrogels. The released 5-FU from all except hydrogel (GEL-5) remained biologically active against human colon cancer cell lines [HT29 (IC50 = 110-190 μg ml(-1)) and HCT116 (IC50 = 210-390 μg ml(-1))] but not human skin fibroblast cells [BJ (CRL2522); IC50 ≥ 1000 μg ml(-1)]. This implies that the copolymer hydrogels (1-4) were able to release 5-FU effectively to colon cancer cells but not normal human skin fibroblast cells. This is probably due to the shorter doubling time that results in reduced pH in colon cancer cells when compared to fibroblast cells. These pH sensitive hydrogels showed well defined cell apoptosis in HCT116 cells through series of events such as chromatin condensation, membrane blebbing, and formation of apoptotic bodies. No cell killing was observed in the case of blank hydrogels. The results showed the potential of these stimuli responsive polymer hydrogels as a carrier for colon cancer delivery.

Matched MeSH terms: Hydrogels
Effect of MgO nanofillers on burst release reduction from hydrogel nanocomposites

Hezaveh H, Muhamad II

J Mater Sci Mater Med, 2013 Jun;24(6):1443-53.
PMID: 23515904 DOI: 10.1007/s10856-013-4914-5

In this study, MgO nanoparticles are applied to control the initial burst release by modification of matrix structure, thereby affecting the release mechanism. The effects of MgO nanofiller loading on the in vitro release of a model drug are investigated. Surface topography and release kinetics of hydrogel nanocomposites are also studied in order to have better insight into the release mechanism. It was found that the incorporation of MgO nanofillers can significantly decrease the initial burst release. The effect of genipin (GN) on burst release was also compared with MgO nanoparticles, and it was found that the impact of MgO on burst release reduction is more obvious than GN; however, GN cross-linking caused greater final release compared to blanks and nanocomposites. To confirm the capability of nanocomposite hydrogels to reduce burst release, the release of β-carotene in Simulated Gastric Fluid and Simulated Intestinal Fluid was also carried out. Thus, the application of MgO nanoparticles seems to be a promising strategy to control burst release.

Matched MeSH terms: Hydrogels/chemistry*
Novel chitosan derivative based composite scaffolds with enhanced angiogenesis; potential candidates for healing chronic non-healing wounds

Rizwan M, Yahya R, Hassan A, Yar M, Abd Halim AA, Rageh Al-Maleki A, et al.

J Mater Sci Mater Med, 2019 Jun 11;30(6):72.
PMID: 31187295 DOI: 10.1007/s10856-019-6273-3

The success of wound healing depends upon the proper growth of vascular system in time in the damaged tissues. Poor blood supply to wounded tissues or tissue engineered grafts leads to the failure of wound healing or rejection of grafts. In present paper, we report the synthesis of novel organosoluble and pro-angiogenic chitosan derivative (CSD) by the reaction of chitosan with 1,3-dimethylbarbituric acid and triethylorthoformate (TEOF). The synthesized material was characterized by FTIR and 13C-NMR to confirm the incorporated functional groups and new covalent connectivities. Biodegradability of the synthesized chitosan derivative was tested in the presence of lysozyme and was found to be comparable with CS. The cytotoxicity and apoptosis effect of new derivative was determined against gastric adenocarcinoma (AGS) cells and was found to be non-toxic. The CSD was found to be soluble in majority of organic solvents. It was blended with polycaprolactone (PCL) to form composite scaffolds. From an ex ovo CAM assay, it was noted that CSD stimulated the angiogenesis.

Matched MeSH terms: Hydrogels/chemistry
Treatment for diabetic ulcer wounds using a fern tannin optimized hydrogel formulation with antibacterial and antioxidative properties

Lai JC, Lai HY, Nalamolu KR, Ng SF

J Ethnopharmacol, 2016 08 02;189:277-89.
PMID: 27208868 DOI: 10.1016/j.jep.2016.05.032

ETHNOPHARMACOLOGICAL RELEVANCE: Blechnum orientale Linn. (B. orientale) is a fern traditionally used by the natives as a poultice to treat wounds, boils, ulcers, blisters, abscesses, and sores on the skin.
AIM OF THE STUDY: To investigate the wound healing ability of a concentrated extract of B. orientale in a hydrogel formulation in healing diabetic ulcer wounds.
MATERIALS AND METHODS: The water extract from the leaves of B. orientale was separated from the crude methanolic extract and subjected to flash column chromatography techniques to produce concentrated fractions. These fractions were tested for phytochemical composition, tannin content, antioxidative and antibacterial activity. The bioactive fraction was formulated into a sodium carboxymethylcellulose hydrogel. The extract-loaded hydrogels were then characterized and tested on excision ulcer wounds of streptozotocin-induced diabetic rats. Wound size was measured for 14 days. Histopathological studies were conducted on the healed wound tissues to observe for epithelisation, fibroblast proliferation and angiogenesis. All possible mean values were subjected to statistical analysis using One-way ANOVA and post-hoc with Tukey's T-test (P<0.05).
RESULTS: One fraction exhibited strong antioxidative and antibacterial activity. The fraction was also highly saturated with tannins, particularly condensed tannins. Fraction W5-1 exhibited stronger antioxidant activity compared to three standards (α-Tocopherol, BHT and Trolox-C). Antibacterial activity was also present, and notably bactericidal towards Methicillin-resistant Staphylococcus aureus (MRSA) at 0.25mg/ml. The extract-loaded hydrogels exhibited shear-thinning properties, with high moisture retention ability. The bioactive fraction at 4% w/w was shown to be able to close diabetic wounds by Day 12 on average. Other groups, including controls, only exhibited wound closure by Day 14 (or not at all). Histopathological studies had also shown that extract-treated wounds exhibited re-epithelisation, higher fibroblast proliferation, collagen synthesis, and angiogenesis.
CONCLUSION: The ethnopharmacological effects of using B. orientale as a topical treatment for external wounds was validated and was also significantly effective in treating diabetic ulcer wounds. Thus, B. orientale extract hydrogel may be presented as a potential treatment for diabetic ulcer wounds.

Matched MeSH terms: Hydrogels
Particle designs for the stabilization and controlled-delivery of protein drugs by biopolymers: a case study on insulin

Lim HP, Tey BT, Chan ES

J Control Release, 2014 Jul 28;186:11-21.
PMID: 24816070 DOI: 10.1016/j.jconrel.2014.04.042

Natural biopolymers have attracted considerable interest for the development of delivery systems for protein drugs owing to their biocompatibility, non-toxicity, renewability and mild processing conditions. This paper offers an overview of the current status and future perspectives of particle designs using biopolymers for the stabilization and controlled-delivery of a model protein drug--insulin. We first describe the design criteria for polymeric encapsulation and subsequently classify the basic principles of particle fabrication as well as the existing particle designs for oral insulin encapsulation. The performances of these existing particle designs in terms of insulin stability and in vitro release behavior in acidic and alkaline media, as well as their in vivo performance are compared and reviewed. This review forms the basis for future works on the optimization of particle design and material formulation for the development of an improved oral delivery system for protein drugs.

Matched MeSH terms: Hydrogels/chemistry
Enhanced paracellular delivery of vaccine by hydrogel microparticles-mediated reversible tight junction opening for effective oral immunization

Chen XY, Butt AM, Mohd Amin MCI

J Control Release, 2019 10;311-312:50-64.
PMID: 31465827 DOI: 10.1016/j.jconrel.2019.08.031

The current conventional injectable vaccines face several drawbacks such as inconvenience and ineffectiveness in mucosal immunization. Therefore, the current development of effective oral vaccines is vital to enable the generation of dual systemic and mucosal immunity. In the present study, we examine the potential of pH-responsive bacterial nanocellulose/polyacrylic acid (BNC/PAA) hydrogel microparticles (MPs) as an oral vaccine carrier. In-vitro entrapment efficiency and release study of Ovalbumin (Ova) demonstrated that as high as 72% of Ova were entrapped in the hydrogel, and the release of loaded Ova was pH-dependent. The released Ova remained structurally conserved as evident by Western blot and circular dichroism. Hydrogel MPs reduced the TEER measurement of HT29MTX/Caco2/Raji B triple co-culture monolayer by reversibly opening the tight junctions (TJs) as shown in the TEM images. The ligated ileal loop assay revealed that hydrogel MPs could facilitate the penetration of FITC-Ova into the Peyer's patches in small intestine. Ova and cholera toxin B (CTB) were utilized in in-vivo oral immunization as model antigen and mucosal adjuvant. The in-vivo immunization revealed mice orally administered with Ova and CTB-loaded hydrogel MPs generated significantly higher level of serum anti-Ova IgG and mucosal anti-Ova IgA in the intestinal washes, compared to intramuscular administrated Ova. These results conclude that BNC/PAA hydrogel MPs is a potential oral vaccine carrier for effective oral immunization.

Matched MeSH terms: Hydrogels/administration & dosage*
Self-assembled three-dimensional reduced graphene oxide-based hydrogel for highly efficient and facile removal of pharmaceutical compounds from aqueous solution

Umbreen N, Sohni S, Ahmad I, Khattak NU, Gul K

J Colloid Interface Sci, 2018 Oct 01;527:356-367.
PMID: 29843021 DOI: 10.1016/j.jcis.2018.05.010

Herein, self-assembled three-dimensional reduced graphene oxide (RGO)-based hydrogels were synthesized and characterized in detail. A thorough investigation on the uptake of three widely used pharmaceutical drugs, viz. Naproxen (NPX), Ibuprofen (IBP) and Diclofenac (DFC) was carried out from aqueous solutions. To ensure the sustainability of developed hydrogel assembly, practically important parameters such as desorption, recyclability and applicability to real samples were also evaluated. Using the developed 3D hydrogels as adsorptive platforms, excellent decontamination for the above mentioned persistent pharmaceutical drugs was achieved in acidic pH with a removal efficiency in the range of 70-80%. These hydrogels showed fast adsorption kinetics and experimental findings were fitted to different kinetic models, such as pseudo-first order, pseudo-second order, intra-particle and the Elovich models in an attempt to better understand the adsorption kinetics. Furthermore, equilibrium adsorption data was fitted to the Langmuir and Freundlich models, where relatively higher R2 values obtained in case of former one suggested that monolayer adsorption played an important part in drug uptake. Thermodynamic aspects were also studied and negative ΔG0 values obtained indicated the spontaneous nature of adsorption process. The study was also extended to check practical utility of as-prepared hydrogels by spiking real aqueous samples with drug solution, where high % recoveries obtained for NPX, IBP and DFC were of particular importance with regard to prospective application in wastewater treatment systems. We advocate RGO-based hydrogels as environmentally benign, readily recoverable/recyclable material with excellent adsorption capacity for application in wastewater purification.

Matched MeSH terms: Hydrogels/chemistry*
Facile asymmetric modification of graphene nanosheets using κ-carrageenan as a green template

Tiong ACY, Tan IS, Foo HCY, Lam MK, Mahmud HB, Lee KT

J Colloid Interface Sci, 2022 Feb;607(Pt 2):1131-1141.
PMID: 34571300 DOI: 10.1016/j.jcis.2021.09.042

The synthesis of Janus nanosheets using κ-carrageenan (κ-Ca) as a green template endows a greener and more straightforward method compared to traditional approaches of using wax template. We hypothesize that the hydrogen bonding interaction between κ-Ca and graphene oxide (GO) allows partial masking of GO's single facet, paving the way for the asymmetric modification of the exposed surface. GO is first encapsulated within the porous hydrogel matrix formed by κ-Ca to isolate one of the facets. The exposed surface was then selectively hydrophobized to produce an amphiphilic asymmetrically modified graphene oxide (AMGO). The properties of AMGO synthesized under different κ-Ca/GO ratios were studied. The κ-Ca/GO interactions and the properties of GO and AMGO were investigated and characterized. AMGO was successfully produced with a yield of 90.37 % under optimized synthesis conditions. The separation of κ-Ca and AMGO was conducted without organic solvents, and the κ-Ca could be subsequently recovered. Furthermore, the porous hydrogel matrix formed by κ-Ca and GO exhibited excellent shape-retaining properties with high thermal tolerance of up to 50 °C. Given these benefits, this newly developed method endows sustainability and open the possibility of formulating more flexible material synthesis protocols.

Matched MeSH terms: Hydrogels
Sea cucumber (Stichopus hermanii) based hydrogel to treat burn wounds in rats

Zohdi RM, Zakaria ZA, Yusof N, Mustapha NM, Abdullah MN

J Biomed Mater Res B Appl Biomater, 2011 Jul;98(1):30-7.
PMID: 21504052 DOI: 10.1002/jbm.b.31828

Malaysian sea cucumber was incorporated into hydrogel formulation by using electron beam irradiation technique and was introduced as novel cross-linked Gamat Hydrogel dressing. This study investigated whether Gamat Hydrogel enhanced repair of deep partial skin thickness burn wound in rats and its possible mechanism. Wounds were treated with either Gamat Hydrogel, control hydrogel, OpSite® film dressing or left untreated. Skin samples were taken at 7, 14, 21, and 28 days post burn for histological and molecular evaluations. Gamat Hydrogel markedly enhanced wound contraction and improved histological reorganization of the regenerating tissue. Furthermore, the dressing modulated the inflammatory responses, stimulated the activation and proliferation of fibroblasts, and enhanced rapid production of collagen fiber network with a consequently shorter healing time. The level of proinflammatory cytokines; IL-1α, IL-1β, and IL-6, were significantly reduced in Gamat Hydrogel treated wounds compared with other groups as assessed by reverse transcription-polymerase chain reaction (RT-PCR). In summary, our results showed that Gamat Hydrogel promoted burn wound repair via a complex mechanism involving stimulation of tissue regeneration and regulation of pro-inflammatory cytokines. The resultant wound healing effects were attributed to the synergistic effect of the hydrogel matrix and incorporated sea cucumber.

Matched MeSH terms: Hydrogels/pharmacology*; Hydrogels/chemistry
Fabrication and evaluation of bacterial nanocellulose/poly(acrylic acid)/graphene oxide composite hydrogel: Characterizations and biocompatibility studies for wound dressing

Chen XY, Low HR, Loi XY, Merel L, Mohd Cairul Iqbal MA

J Biomed Mater Res B Appl Biomater, 2019 08;107(6):2140-2151.
PMID: 30758129 DOI: 10.1002/jbm.b.34309

Graphene oxide (GO) is a potential material for wound dressing due to its excellent biocompatibility and mechanical properties. This study evaluated the effects of GO concentration on the synthesis of bacterial nanocellulose (BNC)-grafted poly(acrylic acid) (AA)-graphene oxide (BNC/P(AA)/GO) composite hydrogel and its potential as wound dressing. Hydrogels were successfully synthesized via electron-beam irradiation. The hydrogels were characterized by their mechanical properties, bioadhesiveness, water vapor transmission rates (WVTRs), water retention abilities, water absorptivity, and biocompatibility. Fourier transform infrared analysis showed the successful incorporation of GO into hydrogel. Thickness, gel fraction determination and morphological study revealed that increased GO concentration in hydrogels leads to reduced crosslink density and larger pore size, resulting in increased WVTR. Thus, highest swelling ratio was found in hydrogel with higher amount of GO (0.09 wt %). The mechanical properties of the composite hydrogel were maintained, while its hardness and bioadhesion were reduced with higher GO concentration in the hydrogel, affirming the durable and easy removable properties of a wound dressing. Human dermal fibroblast cell attachment and proliferation studies showed that biocompatibility of hydrogel was improved with the inclusion of GO in the hydrogel. Therefore, BNC/P(AA)/GO composite hydrogel has a potential application as perdurable wound dressing. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2140-2151, 2019.

Matched MeSH terms: Hydrogels/chemistry*
Formulation and in vitro and in vivo evaluation of a new osteoprotegerin-chitosan gel for bone tissue regeneration

Jayash SN, Hashim NM, Misran M, Baharuddin NA

J Biomed Mater Res A, 2017 02;105(2):398-407.
PMID: 27684563 DOI: 10.1002/jbm.a.35919

The osteoprotegerin (OPG) system plays a critical role in bone remodelling by regulating osteoclast formation and activity. The study aimed to determine the physicochemical properties and biocompatibility of a newly formulated OPG-chitosan gel. The OPG-chitosan gel was formulated using human OPG protein and water-soluble chitosan. The physicochemical properties were determined using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Gel morphology was determined using scanning electron microscopy (SEM) and then it was subjected to a protein release assay and biodegradability test. An in vitro cytotoxicity test on normal human periodontal ligament (NHPL) fibroblasts and normal human (NH) osteoblasts was carried out using the AlamarBlue assay. In vivo evaluation in a rabbit model involved creating critical-sized defects in calvarial bone, filling with the OPG-chitosan gel and sacrificing at 12 weeks. In vitro results demonstrated that the 25 kDa OPG-chitosan gel had the highest rate of protein release and achieved 90% degradation in 28 days. At 12 weeks, the defects filled with 25 kDa OPG-chitosan gel showed significant (p

Matched MeSH terms: Hydrogels/pharmacology; Hydrogels/chemistry
Methylene blue removal by using pectin-based hydrogels extracted from dragon fruit peel waste using gamma and microwave radiation polymerization techniques

Abdullah MF, Azfaralariff A, Lazim AM

J Biomater Sci Polym Ed, 2018 10;29(14):1745-1763.
PMID: 29989528 DOI: 10.1080/09205063.2018.1489023

This research aims to compare the ability of smart hydrogel in removing the methylene blue prepared by using two different radiation methods. The extracted pectin from the dragon fruit peel (Hylocereus polyrhizus) was used with acrylic acid (AA) to produce a polymerized hydrogel through gamma and microwave radiation. The optimum hydrogel swelling capacity was obtained by varying the dose of radiation, pectin to AA ratio and pH used. From the array of samples, the ideal hydrogel was obtained at pH 8 with a ratio of 2:3 (pectin: AA) using 10 kGy and 400 W radiated gamma and microwave respectively. The performance of both hydrogels namely as Pc/AA(G) (gamma) and Pc/AA(Mw) (microwave) were investigated using methylene blue (MB) adsorption studies. In this study, three variables were manipulated, pH and MB concentration and hydrogel mass in order to find the optimum condition for the adsorption. Results showed that 20 mg of Pc/AA(G) performed the highest MB removal which was about 45% of 20 mg/L MB at pH 8. While 30 mg of Pc/AA(Mw) able to remove up to 35% of 20 mg/L MB at the same pH condition. To describe the adsorption mechanism, both kinetic models pseudo-first-order, pseudo-second-order were employed. The results from kinetic data showed that it fitted the pseudo-first-order as compared to pseudo-second-order model equation. This study provides alternative of green, facile and affective biomaterial for dye absorbents that readily available.

Matched MeSH terms: Hydrogels/chemistry*

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