Displaying publications 1 - 20 of 119 in total

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  1. Dabbagh A, Abdullah BJ, Ramasindarum C, Abu Kasim NH
    Ultrason Imaging, 2014 Oct;36(4):291-316.
    PMID: 24626566 DOI: 10.1177/0161734614526372
    Tissue-mimicking phantoms that are currently available for routine biomedical applications may not be suitable for high-temperature experiments or calibration of thermal modalities. Therefore, design and fabrication of customized thermal phantoms with tailored properties are necessary for thermal therapy studies. A multitude of thermal phantoms have been developed in liquid, solid, and gel forms to simulate biological tissues in thermal therapy experiments. This article is an attempt to outline the various materials and techniques used to prepare thermal phantoms in the gel state. The relevant thermal, electrical, acoustic, and optical properties of these phantoms are presented in detail and the benefits and shortcomings of each type are discussed. This review could assist the researchers in the selection of appropriate phantom recipes for their in vitro study of thermal modalities and highlight the limitations of current phantom recipes that remain to be addressed in further studies.
    Matched MeSH terms: Gels/chemistry*
  2. Mat Amin N
    Trop Biomed, 2004 Dec;21(2):57-60.
    PMID: 16493399
    Naegleria fowleri is a free-living amoeba, known as a causative agent for a fatal disease of the central nervous system (CNS) in man such as Primary amoebic meningoencephalitis (PAM). Factors contributing to its pathogenicity and its distribution in the environment have been investigated by previous researchers. In case of its pathogenicity, several enzymes such as phospolipase A and sphingomyelinase, have been proposed to probably act as aggressors in promoting PAM but no study so far have been conducted to investigate the presence of proteinase enzyme in this amoeba although a 56kDa cystein proteinase enzyme has been identified in Entamoeba histolytica as an important contributing factor in the amoeba's virulence. In this preliminary study, a pathogenic amoeba, Naegleria fowleri (strain NF3) was examined for the presence of proteinases. Samples of enzymes in this amoeba were analysed by electrophoresis using SDS-PAGE-gelatin gels. The results showed that this amoeba possesses at least two high molecular weight proteinases on gelatin gels; their apparent molecular weights are approximately 128 kDa and approximately 170 kDa. Band of approximately 128 kDa enzyme is membrane-associated and its activity is higher at alkaline pH compared with lower pH; at lower pH, its activity is greatly stimulated by DTT. The approximately 170 kDa band enzyme appears to be inactivated at pH 8.0, at lower ph its activity is higher and DTT-dependance. The activity of this enzyme is partially inhibited by inhibitor E-64 but markedly inhibited to antipain suggesting it belongs to the cysteine proteinase group.
    Matched MeSH terms: Gels
  3. Katas H, Wen CY, Siddique MI, Hussain Z, Mohd Fadhil FH
    Ther Deliv, 2017 01;8(3):137-150.
    PMID: 28145827 DOI: 10.4155/tde-2016-0075
    AIM: Chitosan (CS) has been extensively studied as drug delivery systems for wound healing. Results/methodology: CS nanoparticles were loaded with curcumin (Cur) and DsiRNA against prostaglandin transporter gene and they were incorporated into 20 and 25% w/v Pluronic F-127. The gels were later analyzed for their rheology, gelation temperature (Tgel), morphology, drug incorporation and in vitro drug release. The particle size was in the range of 231 ± 17-320 ± 20 nm, depending on CS concentration. The gels had Tgel of 23-28°C and exhibited sustained drug release with high accumulated amount of drugs over 48 h.

    CONCLUSION: A thermo-sensitive gel containing Cur/DsiRNA CS nanoparticles was successfully developed and has a great potential to be further developed.

    Matched MeSH terms: Gels
  4. Fong Yen W, Basri M, Ahmad M, Ismail M
    ScientificWorldJournal, 2015;2015:495271.
    PMID: 25853145 DOI: 10.1155/2015/495271
    Galantamine hydrobromide is formulated in tablets and capsules prescribed through oral delivery for the treatment of Alzheimer's disease. However, oral delivery of drugs can cause severe side effects such as nausea, vomiting, and gastrointestinal disturbance. Transdermal delivery of galantamine hydrobromide could avoid these unwanted side effects. In this work, galantamine hydrobromide was formulated in gel drug reservoir which was then fabricated in the transdermal patch. The in vitro drug release studies revealed that the drug release from the donor chamber to receptor chamber of Franz diffusion cell was affected by the amount of polymer, amount of neutralizer, amount of drug, types of permeation enhancer, and amount of permeation enhancer. Visual observations of the gels showed that all formulated gels are translucent, homogeneous, smooth, and stable. These gels have pH in the suitable range for skin. The gel also showed high drug content uniformity. Hence, this formulation can be further used in the preparation of transdermal patch drug delivery system.
    Matched MeSH terms: Gels*
  5. Mardziah CM, Sopyan I, Hamdi M, Ramesh S
    Med J Malaysia, 2008 Jul;63 Suppl A:79-80.
    PMID: 19024993
    Improvement of the mechanical properties of hydroxyapatite (HA) can be achieved by the incorporation of metal. In addition, incorporation of strontium ion into HA crystal structures has been proved effective to enhance biochemical properties of bone implant. In this research, strontium-doped HA powder was developed via a sol-gel method to produce extraordinarily fine strontium-doped HA (Sr-doped HA) powder. XRD measurement had shown that the powder contained hydroxyapatite phase only for all doping concentration except for 2%, showing that Sr atoms have suppressed the appearance of beta-TCP as the secondary phase. Morphological evaluation by FESEM measurement shows that the particles of the Sr-doped HA agglomerates are globular in shape with an average size of 1-2 microm in diameter while the primary particles have a diameter of 30-150 nm in average.
    Matched MeSH terms: Gels
  6. Iskandar SM, Elias S, Jumiah H, Asri MT, Masrianis A, Ab Rahman MZ, et al.
    Med J Malaysia, 2004 May;59 Suppl B:212-3.
    PMID: 15468893
    The radiation-response characteristics of polymetharylic acid gel dosimeter prepared with different concentrations of monomer and cross-linker is described in these studies. The dosimeters were prepared under the hypoxic condition in a glove box and were then irradiated with gamma-rays produced by Co-60 radionuclide that was generated at 1.25MeV energy. The irradiation took place at different doses ranged from 0Gy to 19Gy. Due to the radiation activities, chain-reaction polymerisation processes had taken place in the formation of polymethacrylic acid (PMAA) gel, which cause the dose response mechanism increased in the NMR relaxation rates of protons. It has been observed that for higher concentration of monomer and cross-linker, the polymerization rate was increased.
    Matched MeSH terms: Gels
  7. Tay PYS, Lenton EA
    Med J Malaysia, 2005 Jun;60(2):151-7.
    PMID: 16114155
    This is a prospeve randomised study designed to clarify the impact of various luteal support regimes (HCG and progesterone) on progesterone profiles and pregnancy outcomes. This study involved subjects undergone down regulated. stimulated IVF cycles using various types of luteal support, namely: Cyclogest (n=35). Crinone gel (n=36), various doses of Utrogestan (n=55) and HCG (n=35). Various doses of Utrogestan (administered vaginally), Crinone gel (progesterone administered vaginally) and Cyclogest (progesterone administered rectally) supplementation induced similar end plasma progesterone concentrations ranging from 26 to 32 mmnl/l. These progesterone regimes produced no significant differences. Hence, the impact of exogenous proge,terone supplement was relatively trivial and did not 'stabilise' the sub-optimal luteal phase. In contrast, two small HCG injections during the early and mid-luteal phase possessed a much greater ability to 'stabilise' progesterone profiles. Despite this additional advantage, implantation and pregnancy rates with either HCG or progesterone supplements were similar. Although none of these forms of luteal support adequately 'normalised' luteal progesterone profiles, this did not appear to be detrimental to the process of implantation.
    Matched MeSH terms: Gels
  8. Wong TW, Sumiran N
    J Pharm Pharmacol, 2014 May;66(5):646-57.
    PMID: 24329400 DOI: 10.1111/jphp.12192
    Objective: Examine the formation of pectin-insulin nanoparticles and their blood glucose lowering properties.

    Methods: The calcium pectinate nanoparticles were prepared by ionotropic gelation method, with alginate, sodium chloride or Tween 80 as additive. Their in vitro physicochemical, drug release and in vivo blood glucose lowering characteristics were evaluated.

    Key findings: Spherical calcium pectinate-insulin nanoparticles were characterized by size, zeta potential, insulin content and insulin association efficiency of 348.4 ± 12.9 nm, -17.9 ± 0.8 mV, 8.4 ± 1.0% and 63.8 ± 7.4%, respectively. They released less than 25% insulin following 24 h in simulated intestinal medium and exhibited delayed blood glucose lowering effect in rats. Incorporation of solubilizer sodium chloride or Tween 80 into nanoparticles did not enhance blood glucose lowering capacity owing to sodium chloride reduced matrix insulin content and Tween 80 interacted with water and had its blood glucose dilution effect negated. Combination of nanoparticles with alginate gel to allow prolonged intestinal residence and more insulin release did not enhance their blood glucose lowering capacity because of calcium alginate-cross-linked gel formation that could retard insulin release and migration into systemic circulation.

    Conclusion: Physicochemical responses of additives in vivo affected blood glucose regulation property of pectin-insulin nanoparticles.

    Keywords: Tween 80; alginate; insulin; nanoparticle; pectin.
    Matched MeSH terms: Gels
  9. Arip MN, Heng LY, Ahmad M, Ujang S
    Talanta, 2013 Nov 15;116:776-81.
    PMID: 24148473 DOI: 10.1016/j.talanta.2013.07.065
    The characteristics of a potentiometric biosensor for the determination of permethrin in treated wood based on immobilised cells of the fungus Lentinus sajor-caju on a potentiometric transducer are reported this paper. The potentiometric biosensor was prepared by immobilisation of the fungus in alginate gel deposited on a pH-sensitive transducer employing a photocurable acrylic matrix. The biosensor gave a good response in detecting permethrin over the range of 1.0-100.0 µM. The slope of the calibration curve was 56.10 mV/decade with detection limit of 1.00 µM. The relative standard deviation for the sensor reproducibility was 4.86%. The response time of the sensor was 5 min at optimum pH 8.0 with 1.00 mg/electrode of fungus L. sajor-caju. The permethrin biosensor performance was compared with the conventional method for permethrin analysis using high performance liquid chromatography (HPLC), and the analytical results agreed well with the HPLC method (at 95% confidence limit). There was no interference from commonly used organophosphorus pesticides such as diazinon, parathion, paraoxon, and methyl parathion.
    Matched MeSH terms: Gels
  10. Rozaini MNH, Semail NF, Saad B, Kamaruzaman S, Abdullah WN, Rahim NA, et al.
    Talanta, 2019 Jul 01;199:522-531.
    PMID: 30952293 DOI: 10.1016/j.talanta.2019.02.096
    Molecularly imprinted silica gel (MISG) was incorporated through dispersion in agarose polymer matrix to form a mixed matrix membrane (MMM) and was applied for the determination of three sulfonamide antibiotic compounds (i.e. sulfamethoxazole (SMX), sulfamonomethoxine (SMM), and sulfadiazine (SDZ)) from environmental water samples. Several important microextraction conditions, such as type of desorption solvent, extraction time, amount of sorbent, sample volume, pH, and effect of desorption time, were comprehensively optimized. A preconcentration factors of ≥ 20 was achieved by the extraction of 12.5 mL of water samples using the developed method. This microextraction-HPLC method demonstrated good linearity (1-500 μg L-1) with a coefficient of determination (R2) of 0.9959-0.9999, low limits of detection (0.06-0.17 μg L-1) and limits of quantification (0.20-0.56 μg L-1), good analyte recoveries (80-96%), and acceptable relative standard deviations (< 10%) under the optimized conditions. The method is systematically compared to those reported in the literature.
    Matched MeSH terms: Gels/chemistry
  11. Yusof NA, Kadir WA
    PMID: 19010723 DOI: 10.1016/j.saa.2008.07.019
    Optical test strip based on the use of Br-PADAP as a sensitive reagent immobilised into sol-gel thin film for detection of Hg(II) in aqueous solution had been thoroughly carried out. It has a square-sensing zone (1.0 cm x 1.0 cm) containing the sensitive reagent necessary to produce response to trace level of mercury. This method offer sensitivity and simplicity in detecting Hg(II) as no prior treatment or extraction is required. A linear response was attained in the Hg(II) concentration in the range of 0.5-2.5 ppm with calculated limit of detection of 6.63 ppb. This method also showed a reproducible result with relative standard deviation (R.S.D.) of 2.15% and response time of approximately 5 min. Interference studies showed that Al(III), Co(II) and Ni(II) significantly interfered during the determination. The developed sensor has been validated against Atomic Absorption Spectroscopy method and proven comparable.
    Matched MeSH terms: Gels
  12. Zainudin BM, Rafia MH, Sufarlan AW
    Singapore Med J, 1993 Apr;34(2):148-9.
    PMID: 8266157
    Lignocaine spray for anaesthetising the nasal mucosa for fibreoptic bronchoscopy often causes discomfort to the patient. We compared two techniques of applying nasal topical anaesthesia using either lignocaine spray (group A: 25 patients) or gel (group B: 30 patients) to assess patients' tolerance to the procedure. Both groups received 100 mg of lignocaine in the nostril, 40-50 mg to oropharynx, 120 mg to vocal cords and 40-100 mg to trachea and bronchi. Throat anaesthesia was the most common unpleasant part experienced by both groups of patients (34.5%), followed by examination of bronchi (30.6%) and nasal anaesthesia (21.8%). Significantly more patients in group A experienced discomfort or pain during nasal anaesthesia as compared to group B (p < 0.001). Patients' tolerance to the bronchoscopy was similar in both groups and the examination was performed satisfactorily in all patients. Thus, lignocaine gel is a simple technique, effective and less irritating as compared to lignocaine spray for topical nasal anaesthesia.
    Matched MeSH terms: Gels
  13. Abudula T, Gauthaman K, Mostafavi A, Alshahrie A, Salah N, Morganti P, et al.
    Sci Rep, 2020 11 24;10(1):20428.
    PMID: 33235239 DOI: 10.1038/s41598-020-76971-w
    Non-healing wounds have placed an enormous stress on both patients and healthcare systems worldwide. Severe complications induced by these wounds can lead to limb amputation or even death and urgently require more effective treatments. Electrospun scaffolds have great potential for improving wound healing treatments by providing controlled drug delivery. Previously, we developed fibrous scaffolds from complex carbohydrate polymers [i.e. chitin-lignin (CL) gels]. However, their application was limited by solubility and undesirable burst drug release. Here, a coaxial electrospinning is applied to encapsulate the CL gels with polycaprolactone (PCL). Presence of a PCL shell layer thus provides longer shelf-life for the CL gels in a wet environment and sustainable drug release. Antibiotics loaded into core-shell fibrous platform effectively inhibit both gram-positive and -negative bacteria without inducting observable cytotoxicity. Therefore, PCL coated CL fibrous gel platforms appear to be good candidates for controlled drug release based wound dressing applications.
    Matched MeSH terms: Gels/chemical synthesis; Gels/chemistry
  14. Ahmed MA, Al-Kahtani HA, Jaswir I, AbuTarboush H, Ismail EA
    Saudi J Biol Sci, 2020 Jun;27(6):1596-1601.
    PMID: 32489300 DOI: 10.1016/j.sjbs.2020.03.022
    Gelatin is used as an ingredient in both food and non-food industries as a gelling agent, stabilizer, thickener, emulsifier, and film former. Porcine skins, bovine hides, and cattle bones are the most common sources of gelatin. However, mammalian gelatins are rejected by some consumers due to social, cultural, religious, or health-related concerns. In the present study, gelatin was obtained from camel skin as an alternative source using a combination of processing steps. Central composite design combined with response surface methodology was used to achieve high gelatin yields under different extraction conditions: temperatures of 40, 60, and 80 °C; pH values of 1, 4, and 7; and extraction times of 0.5, 2.0, and 3.5 min. Maximum gelatin yield from camel skin (29.1%) was achieved at 71.87 °C and pH 5.26 after 2.58 min. The extracted gelatin samples were characterized for amino acid profile, foaming capacity, film formation, foam stability, and gel strength (Bloom value). Gelatin nanoparticles were produced, and their morphology and zeta potential were determined. Bloom value of the camel skin gelatin was 340 g. Amino acid analysis revealed that the extracted gelatin showed high glycine and proline contents. Analysis of camel skin gelatin nanoparticle and functional properties revealed high suitability for food and non-food applications, with potential use in the growing global halal food market.
    Matched MeSH terms: Gels
  15. Lee JS, Lo YL, Chye FY
    This study was carried out to elucidate the effect of three types of cation (K+, Ca2+ and Na+) at various concentrations on the gelling properties of untreated Eucheuma cottoni, with the ultimate aim to explore the possibility of utilizing the seaweed in its natural form as gelling agent. Results obtained suggest that E. cottonii also exhibited the dramatic cation specificity of k-carrageenan, in which the dependence of gel strength follows the order: K+ > Ca2+ > Na+. As expected, cations addition exerts adverse effect on the syneresis, water holding capacity and freeze-thaw stability of the seaweed gel. Water holding capcity of the gel is however independent of the increased concentrations of K+(p>0.05). Storage duration and storage temperature significantly (p<0.05) affect the syneresis and water holding capacity of the gel. Among the cations, K+ appears to be better in improving the gel properties of the seaweed.
    Matched MeSH terms: Gels
  16. Sheshala R, Kok YY, Ng JM, Thakur RR, Dua K
    Recent Pat Drug Deliv Formul, 2015;9(3):237-48.
    PMID: 26205681
    Ophthalmic drug delivery system is very interesting and challenging due to the normal physiologically factor of eyes which reduces the bioavailability of ocular products. The development of new ophthalmic dosage forms for existing drugs to improve efficacy and bioavailability, patient compliance and convenience has become one of the main trend in the pharmaceuticals industry. The present review encompasses various conventional and novel ocular drug delivery systems, methods of preparation, characterization and recent research in this area. Furthermore, the information on various commercially available in situ gel preparations and the existing patents of in situ drug delivery systems i.e. in situ gel formation of pectin, in situ gel for therapeutic use, medical uses of in situ formed gels and in situ gelling systems as sustained delivery for front of eye are also covered in this review.
    Matched MeSH terms: Gels
  17. Dizavandi FR, Ghazanfarpour M, Roozbeh N, Kargarfard L, Khadivzadeh T, Dashti S
    Post Reprod Health, 2019 Mar;25(1):11-20.
    PMID: 30786797 DOI: 10.1177/2053369118823365
    OBJECTIVE: The aim of this overview was to evaluate the effectiveness of phytoestrogens on vaginal health and dyspareunia in peri- and post-menopausal women.

    MATERIAL AND METHODS: Three databases including MEDLINE, Scopus and the Cochrane Central Register of Controlled Trials were from inception to August 2017.

    RESULT: Two systematic reviews and 11 RCTs were included in the overview. According to the findings, isoflavones increased the maturation value and attenuated the vaginal atrophy in the post-menopausal women. Topical isoflavones had beneficial effects on the vaginal atrophy. Similar efficacy was found in Pueraria mirifica and conjugated estrogen cream on dryness ( p = 0.277), soreness ( p = 0.124) and irritation ( p = 0.469), as well as discharge ( p = 0.225) and dyspareunia ( p = 0.089). However, the conjugated estrogen cream was more effective compared to Pueraria mirifica ( p > 0.005) regarding maturation index improvement. Comparison of fennel 5% vaginal cream and placebo gel showed significant difference in superficial cells ( p 

    Matched MeSH terms: Gels
  18. Abdul Khalil HPS, Adnan AS, Yahya EB, Olaiya NG, Safrida S, Hossain MS, et al.
    Polymers (Basel), 2020 Aug 06;12(8).
    PMID: 32781602 DOI: 10.3390/polym12081759
    Cellulose nanomaterials from plant fibre provide various potential applications (i.e., biomedical, automotive, packaging, etc.). The biomedical application of nanocellulose isolated from plant fibre, which is a carbohydrate-based source, is very viable in the 21st century. The essential characteristics of plant fibre-based nanocellulose, which include its molecular, tensile and mechanical properties, as well as its biodegradability potential, have been widely explored for functional materials in the preparation of aerogel. Plant cellulose nano fibre (CNF)-based aerogels are novel functional materials that have attracted remarkable interest. In recent years, CNF aerogel has been extensively used in the biomedical field due to its biocompatibility, renewability and biodegradability. The effective surface area of CNFs influences broad applications in biological and medical studies such as sustainable antibiotic delivery for wound healing, the preparation of scaffolds for tissue cultures, the development of drug delivery systems, biosensing and an antimicrobial film for wound healing. Many researchers have a growing interest in using CNF-based aerogels in the mentioned applications. The application of cellulose-based materials is widely reported in the literature. However, only a few studies discuss the potential of cellulose nanofibre aerogel in detail. The potential applications of CNF aerogel include composites, organic-inorganic hybrids, gels, foams, aerogels/xerogels, coatings and nano-paper, bioactive and wound dressing materials and bioconversion. The potential applications of CNF have rarely been a subject of extensive review. Thus, extensive studies to develop materials with cheaper and better properties, high prospects and effectiveness for many applications are the focus of the present work. The present review focuses on the evolution of aerogels via characterisation studies on the isolation of CNF-based aerogels. The study concludes with a description of the potential and challenges of developing sustainable materials for biomedical applications.
    Matched MeSH terms: Gels
  19. Selvanathan V, Yahya R, Ruslan MH, Sopian K, Amin N, Nour M, et al.
    Polymers (Basel), 2020 Feb 27;12(3).
    PMID: 32120814 DOI: 10.3390/polym12030516
    This work is a pioneer attempt to fabricate quasi-solid dye-sensitized solar cell (QSDDSC) based on organosoluble starch derivative. Rheological characterizations of the PhSt-HEC blend based gels exhibited viscoelastic properties favorable for electrolyte fabrication. From amplitude sweep and tack test analyses, it was evident that the inclusion of LiI improved the rigidity and tack property of the gels. On the other hand, the opposite was true for TPAI based gels, which resulted in less rigid and tacky electrolytes. The crystallinity of the gels was found to decline with increasing amount of salt in both systems. The highest photoconversion efficiency of 3.94% was recorded upon addition of 12.5 wt % TPAI and this value is one of the highest DSSC performance recorded for starch based electrolytes. From electrochemical impedance spectroscopy (EIS), it is deduced that the steric hindrance imposed by bulky cations aids in hindering recombination between photoanode and electrolyte.
    Matched MeSH terms: Gels
  20. Raja MA, Katas H, Jing Wen T
    PLoS One, 2015;10(6):e0128963.
    PMID: 26068222 DOI: 10.1371/journal.pone.0128963
    Chitosan (CS) nanoparticles have been extensively studied for siRNA delivery; however, their stability and efficacy are highly dependent on the types of cross-linker used. To address this issue, three common cross-linkers; tripolyphosphate (TPP), dextran sulphate (DS) and poly-D-glutamic acid (PGA) were used to prepare siRNA loaded CS-TPP/DS/PGA nanoparticles by ionic gelation method. The resulting nanoparticles were compared with regard to their physicochemical properties including particle size, zeta potential, morphology, binding and encapsulation efficiencies. Among all the formulations prepared with different cross linkers, CS-TPP-siRNA had the smallest particle size (ranged from 127 ± 9.7 to 455 ± 12.9 nm) with zeta potential ranged from +25.1 ± 1.5 to +39.4 ± 0.5 mV, and high entrapment (>95%) and binding efficiencies. Similarly, CS-TPP nanoparticles showed better siRNA protection during storage at 4˚C and as determined by serum protection assay. TEM micrographs revealed the assorted morphology of CS-TPP-siRNA nanoparticles in contrast to irregular morphology displayed by CS-DS-siRNA and CS-PGA-siRNA nanoparticles. All siRNA loaded CS-TPP/DS/PGA nanoparticles showed initial burst release followed by sustained release of siRNA. Moreover, all the formulations showed low and concentration-dependent cytotoxicity with human colorectal cancer cells (DLD-1), in vitro. The cellular uptake studies with CS-TPP-siRNA nanoparticles showed successful delivery of siRNA within cytoplasm of DLD-1 cells. The results demonstrate that ionically cross-linked CS-TPP nanoparticles are biocompatible non-viral gene delivery system and generate a solid ground for further optimization studies, for example with regard to steric stabilization and targeting.
    Matched MeSH terms: Gels/chemistry
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