MyMedR

Displaying publications 41 - 48 of 48 in total

Abstract:

Sort:

Fulltext Preparation of hippurate-zinc layered hydroxide nanohybrid and its synergistic effect with tamoxifen on HepG2 cell lines

Hussein Al Ali SH, Al-Qubaisi M, Hussein MZ, Zainal Z, Hakim MN

Int J Nanomedicine, 2011;6:3099-111.
PMID: 22163163 DOI: 10.2147/IJN.S24510

A new simple preparation method for a hippurate-intercalated zinc-layered hydroxide (ZLH) nanohybrid has been established, which does not need an anion-exchange procedure to intercalate the hippurate anion into ZLH interlayers.

Matched MeSH terms: Zinc Compounds/chemistry*
Fulltext Folic acid targeted Mn:ZnS quantum dots for theranostic applications of cancer cell imaging and therapy

Bwatanglang IB, Mohammad F, Yusof NA, Abdullah J, Hussein MZ, Alitheen NB, et al.

Int J Nanomedicine, 2016;11:413-28.
PMID: 26858524 DOI: 10.2147/IJN.S90198

In this study, we synthesized a multifunctional nanoparticulate system with specific targeting, imaging, and drug delivering functionalities by following a three-step protocol that operates at room temperature and solely in aqueous media. The synthesis involves the encapsulation of luminescent Mn:ZnS quantum dots (QDs) with chitosan not only as a stabilizer in biological environment, but also to further provide active binding sites for the conjugation of other biomolecules. Folic acid was incorporated as targeting agent for the specific targeting of the nanocarrier toward the cells overexpressing folate receptors. Thus, the formed composite emits orange-red fluorescence around 600 nm and investigated to the highest intensity at Mn(2+) doping concentration of 15 at.% and relatively more stable at low acidic and low alkaline pH levels. The structural characteristics and optical properties were thoroughly analyzed by using Fourier transform infrared, X-ray diffraction, dynamic light scattering, ultraviolet-visible, and fluorescence spectroscopy. Further characterization was conducted using thermogravimetric analysis, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray fluorescence, and X-ray photoelectron spectroscopy. The cell viability and proliferation studies by means of MTT assay have demonstrated that the as-synthesized composites do not exhibit any toxicity toward the human breast cell line MCF-10 (noncancer) and the breast cancer cell lines (MCF-7 and MDA-MB-231) up to a 500 µg/mL concentration. The cellular uptake of the nanocomposites was assayed by confocal laser scanning microscope by taking advantage of the conjugated Mn:ZnS QDs as fluorescence makers. The result showed that the functionalization of the chitosan-encapsulated QDs with folic acid enhanced the internalization and binding affinity of the nanocarrier toward folate receptor-overexpressed cells. Therefore, we hypothesized that due to the nontoxic nature of the composite, the as-synthesized nanoparticulate system can be used as a promising candidate for theranostic applications, especially for a simultaneous targeted drug delivery and cellular imaging.

Matched MeSH terms: Zinc Compounds/chemistry*
A search for novel thermoluminescent radiation dosimeter media

Al-Hinai KH, Benkara Mohd N, Rozullyah Zulkepely N, Md Nor R, Mohd Amin Y, Bradley DA

Appl Radiat Isot, 2013 Dec;82:126-9.
PMID: 23978507 DOI: 10.1016/j.apradiso.2013.07.013

We describe two example pilot efforts to help define new thermoluminescent dosimeter media. The first concerns ZnS:Mn nanophosphors, prepared by chemical precipitation using zinc and sodium sulfate, doped with manganese sulfate at concentrations varying from 1 to 3mol. The second concerns chemical vapor deposited diamond, produced as a thin film or as amorphous carbon on a single-crystal silicon substrate, each deposited under the same conditions, use being made of the hot filament-chemical vapor deposition (HFCVD) technique. The gas concentrations used were 1% CH4 in 99% H2 and 25% CH4 in 75% H2. Characterization of formations used FESEM, XRD and EDX. The nanophosphors consisted of particles of sizes in the range 85-150nm, the thermoluminescence (TL)-based radiation detection medium giving rise to a single peaked glow curve of maximum yield at a temperature of 250°C at a heating rate of 5°C/s. The TL response increased linearly with radiation dose, ZnS doped to 2mol of Mn being found the most sensitive. Regarding chemical vapor deposited (CVD) carbon, inappreciable TL was found for the resultant ball-like amorphous carbon films, graphite, and the silicon substrate, whereas CVD diamond films showed a promising degree of linearity with dose. For both the ZnS and diamond samples, TL signal fading was appreciable, being some 40% per day for ZnS and>50% per day for CVD films even under storage in the dark at room temperature, making it apparent that there is need to adjust parameters such as the size of nanoparticles.

Matched MeSH terms: Zinc Compounds
Fulltext Enriched Mechanical Strength and Bone Mineralisation of Electrospun Biomimetic Scaffold Laden with Ylang Ylang Oil and Zinc Nitrate for Bone Tissue Engineering

Mani MP, Jaganathan SK, Supriyanto E

Polymers (Basel), 2019 Aug 08;11(8).
PMID: 31398835 DOI: 10.3390/polym11081323

Scaffolds supplemented with naturally derived materials seem to be a good choice in bone tissue engineering. This study aims to develop polyurethane (PU) nanofibers added with ylang ylang (YY) and zinc nitrate (ZnNO3) using the electrospinning method. Field emission scanning electron microscopy (FESEM) images showed that the diameter of the PU nanofibers (869 ± 122 nm) was reduced with the addition of YY and ZnNO3 (PU/YY-467 ± 132 nm and PU/YY/ZnNO3-290 ± 163 nm). Fourier transform infrared (FTIR), a thermal gravimetric analysis (TGA) and an X-ray diffraction (XRD) analysis confirmed the interactions between PU with YY and ZnNO3. In addition, a thermal gravimetric analysis (TGA) study revealed the improved thermal stability for PU/YY and a slight reduction in the thermal stability for PU/YY/ZnNO3. A tensile test indicated that the addition of YY and ZnNO3 (PU/YY-12.32 MPa and PU/YY/ZnNO3-14.90 MPa) improved the mechanical properties of the pristine PU (6.83 MPa). The electrospun PU/YY (524 nm) and PU/YY/ZnNO3 (284 nm) showed a reduced surface roughness when compared with the pristine PU (776 nm) as depicted in the atomic force microscopy (AFM) analysis. The addition of YY and ZnNO3 improved the anticoagulant and biocompatibility nature of the pristine PU. Furthermore, the bone mineralization study depicted the improved calcium deposition in the fabricated composites (PU/YY-7.919% and PU/YY/ZnNO3-10.150%) compared to the pristine PU (5.323%). Hence, the developed composites with desirable physico-chemical properties, biocompatibility and calcium deposition can serve as plausible candidates for bone tissue engineering.

Matched MeSH terms: Zinc Compounds
Fulltext Effect of luting cement to push-out bond strength of fibre reinforced post

Yahya, N.A., Lui, J.L., Chong, K.W.A., Abu Kasim, N.H., Radzi, Z., Lim, C.M.

Ann Dent, 2008;15(1):11-19.
MyJurnal

The objective of this study was to investigate the effect of various luting cement systems on bond strength of fibre-reinforced posts to root canal dentine. 40 extracted single rooted sound premolar teeth were root filled, decoronated and randomly divided into four groups. Fibre posts, Aestheti- Plus™ (Bisco,Inc. Schaumburg, IL, USA) were cemented using four luting cements: Group A (control): Elite 100® Zinc phosphate (GC Corp, Japan), Group B: Calibra ™ Esthetic Resin Cement (Dentsply Caulk, USA), Group C: RelyX ARC Adhesive Resin (3M ESPE), Group D: RelyX Unicem Aplicap (3M ESPE). Each root was sliced into 2 discs representing the coronal and middle portions of the root canal giving rise to 20 specimens per group. Bond strength was determined using push-out tests and data was analyzed using SPSS version 14.0. The mean bond strength of Group A to Aestheti-Plus™ post was 7.71 MPa (±2.51) and Group B was 5.69 MPa (±3.23). Group C exhibited the lowest mean bond strength, 4.29 MPa (±3.53) while the highest bond strength was obtained from Group D, 7.98 MPa (±2.61). One way ANOVA showed significant interaction between all groups (p=.OOI). Post-hoc Bonferroni test reve;iled that bond strength of Group C was significantly lower compared to Group A (p=.008) and D (p=.004). In conclusion, the mean bond strength of Aestheti- Plus™ post to root canal dentine was highest when cemented with RelyX Unicem resin cement followed by Elite 100® zinc phosphate cement, Calibra and RelyX ARC resin cements. However, the bond strengths of Cali bra and RelyX Unicem resin cements were not significantly different from Elite 100® zinc phosphate cement.

Matched MeSH terms: Zinc Compounds
Fulltext Development of a highly biocompatible antituberculosis nanodelivery formulation based on para-aminosalicylic acid-zinc layered hydroxide nanocomposites

Saifullah B, Arulselvan P, El Zowalaty ME, Fakurazi S, Webster TJ, Geilich B, et al.

ScientificWorldJournal, 2014;2014:401460.
PMID: 25050392 DOI: 10.1155/2014/401460

Tuberculosis is a lethal epidemic, difficult to control disease, claiming thousands of lives every year. We have developed a nanodelivery formulation based on para-aminosalicylic acid (PAS) and zinc layered hydroxide using zinc nitrate salt as a precursor. The developed formulation has a fourfold higher efficacy of PAS against mycobacterium tuberculosis with a minimum inhibitory concentration (MIC) found to be at 1.40 μg/mL compared to the free drug PAS with a MIC of 5.0 μg/mL. The newly developed formulation was also found active against Gram-positive bacteria, Gram-negative bacteria, and Candida albicans. The formulation was also found to be biocompatible with human normal lung cells MRC-5 and mouse fibroblast cells-3T3. The in vitro release of PAS from the formulation was found to be sustained in a human body simulated phosphate buffer saline (PBS) solution at pH values of 7.4 and 4.8. Most importantly the nanocomposite prepared using zinc nitrate salt was advantageous in terms of yield and free from toxic zinc oxide contamination and had higher biocompatibility compared to one prepared using a zinc oxide precursor. In summary, these promising in vitro results are highly encouraging for the continued investigation of para-aminosalicylic acid and zinc layered hydroxide nanocomposites in vivo and eventual preclinical studies.

Matched MeSH terms: Zinc Compounds/chemistry
Fulltext Controlled-release formulation of antihistamine based on cetirizine zinc-layered hydroxide nanocomposites and its effect on histamine release from basophilic leukemia (RBL-2H3) cells

Hasan S, Al Ali H, Al-Qubaisi M, Zobir Hussein M, Ismail M, Zainal Z, et al.

Int J Nanomedicine, 2012;7:3351-63.
PMID: 22848164 DOI: 10.2147/IJN.S30809

A controlled-release formulation of an antihistamine, cetirizine, was synthesized using zinc-layered hydroxide as the host and cetirizine as the guest. The resulting well-ordered nanolayered structure, a cetirizine nanocomposite "CETN," had a basal spacing of 33.9 Å, averaged from six harmonics observed from X-ray diffraction. The guest, cetirizine, was arranged in a horizontal bilayer between the zinc-layered hydroxide (ZLH) inorganic interlayers. Fourier transform infrared spectroscopy studies indicated that the intercalation takes place without major change in the structure of the guest and that the thermal stability of the guest in the nanocomposites is markedly enhanced. The loading of the guest in the nanocomposites was estimated to be about 49.4% (w/w). The release study showed that about 96% of the guest could be released in 80 hours by phosphate buffer solution at pH 7.4 compared with about 97% in 73 hours at pH 4.8. It was found that release was governed by pseudo-second order kinetics. Release of histamine from rat basophilic leukemia cells was found to be more sensitive to the intercalated cetirizine in the CETN compared with its free counterpart, with inhibition of 56% and 29%, respectively, at 62.5 ng/mL. The cytotoxicity assay toward Chang liver cells line show the IC₅₀ for CETN and ZLH are 617 and 670 μg/mL, respectively.

Matched MeSH terms: Zinc Compounds/chemistry*
Zinc L-carnosine suppresses inflammatory responses in lipopolysaccharide-induced RAW 264.7 murine macrophages cell line via activation of Nrf2/HO-1 signaling pathway

Ooi TC, Chan KM, Sharif R

Immunopharmacol Immunotoxicol, 2017 Oct;39(5):259-267.
PMID: 28697633 DOI: 10.1080/08923973.2017.1344987

CONTEXT: Zinc L-carnosine (ZnC) is a chelate of Zn and L-carnosine and is used clinically in the treatment of peptic ulcer.
OBJECTIVE: In this study, we aim to investigate the involvement of heme oxygenase-1 (HO-1) in the anti-inflammatory effects of ZnC in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages.
MATERIALS AND METHODS: We used immunoblotting analysis to evaluate the involvement of HO-1 in the anti-inflammatory effects of ZnC and the signaling pathway involved was measured using Dual luciferase reporter assay.
RESULTS: Results from immunoblotting analysis demonstrated that pretreatment of cells with ZnC enhanced the expression of HO-1 in RAW 264.7 cells. Pretreatment of cells with HO-1 inhibitor (tin protoporphyrin IX dichloride) significantly attenuated the inhibitory effects of ZnC on nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression and NF-κB activation in LPS-induced RAW 264.7 cells, suggesting that HO-1 play an important role in the suppression of inflammatory responses induced by ZnC. Furthermore, results from co-immunoprecipitation of Nrf2 and Keap1 and dual luciferase reporter assay showed that pretreatment of ZnC was able to activate the Nrf2 signaling pathway. Treatment of cells with p38 inhibitor (SB203580), c-Jun N-terminal kinase inhibitor (SP600125), and MEK 1/2 inhibitor (U0126) did not significantly suppress the induction of HO-1 by ZnC. Moreover, our present findings suggest that the effects of ZnC on NO production, HO-1 expression, and Nrf2 activation were attributed to its Zn subcomponent, but not l-carnosine.
CONCLUSION: Pretreatment with ZnC was able to activate Nrf2/HO-1 signaling pathway, thus suppressing the expression of inflammatory mediators, such as NO and iNOS in LPS-induced RAW 264.7 cells.

Matched MeSH terms: Zinc Compounds/pharmacology