Displaying publications 21 - 40 of 332 in total

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  1. Cik Rohaida CH, Idris B, Mohd Reusmaazran Y, Rusnah M, Fadzley Izwan AM
    Med J Malaysia, 2004 May;59 Suppl B:156-7.
    PMID: 15468865
    A mixture with different compositions of HA and TCP were synthesize in this work by precipitation method using Ca(NO3)2 4H2 and (NH4)2HPO4 as the starting materials. A mixture with HA and TCP phases in different ratios were produced. The powders were sintered from 1000 degrees C to 1250 degrees C. The phase compositions of the mixtures were then studied via XRD. This work shows that the pH value determines the different phase compositions of the HA-TCP mixture. Chemical analyses were carried out by FTIR. The microstructure was observed under SEM.
    Matched MeSH terms: Biocompatible Materials/analysis; Biocompatible Materials/chemical synthesis*
  2. Inayat-Hussain SH, Rajab NF, Roslie H, Hussin AA, Ali AM, Annuar BO
    Med J Malaysia, 2004 May;59 Suppl B:176-7.
    PMID: 15468875
    Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.
    Matched MeSH terms: Biocompatible Materials/toxicity*
  3. Shamsuria O, Fadilah AS, Asiah AB, Rodiah MR, Suzina AH, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:174-5.
    PMID: 15468874
    The aim of this study was to evaluate the in vitro cytotoxicity of biomaterials; Hydroxyapatite (HA), Natural coral (NC) and Polyhydroxybutarate (PHB). Three different materials used in this study; HA (Ca10(PO4)6(OH)2), NC (CaCO3) and PHB (Polymer) were locally produced by the groups of researcher from Universiti Sains Malaysia. The materials were separately extracted in the complete culture medium (100mg/ml) for 72h and introduced to the osteoblast cells CRL-1543. The viability of osteoblast CRL-1543 cultivated with these extraction materials after 72h incubation period was compared to negative control with neutral red assay by using spectrophotometer at 540nm. The results showed the non-cytotoxicity of the materials. After 72h of incubation period, HA showed 123% viable cells, NC was 99.43% and PHB was 176.75%. In this study, cytotoxicity test dealt mainly with the substances that leached out from the biomaterial. The results obtained showed that the materials were not toxic and also promoted cells growth in the sense of biofunctionality.
    Matched MeSH terms: Biocompatible Materials/toxicity*
  4. Ang CY, Samsudin AR, Karima AM, Nizam A
    Med J Malaysia, 2004 May;59 Suppl B:149-50.
    PMID: 15468862
    The aim of this study was to evaluate the morphological and biological properties of a locally produced "Bovine Bone Sponge" for use in dentistry. Bovine bone sponge was prepared from local calf bone. Endotoxin level and surface properties were investigated. The pore size and water uptake ability were measured and results were compared with the commercial haemostatic agent. The material was tested for its haemostatic property and its inhibition of alveolar bone resorption in a sheep model following dental extraction. Results revealed a significant difference in haemostatic effect, and a shorter bleeding time and a lower rate of alveolar bone resorption in bovine bone sponge compare to a commercial haemostatic agent.
    Matched MeSH terms: Biocompatible Materials*
  5. Rajab NF, Yaakob TA, Ong BY, Hamid M, Ali AM, Annuar BO, et al.
    Med J Malaysia, 2004 May;59 Suppl B:170-1.
    PMID: 15468872
    Hydroxyapatite is the main component of the bone which is a potential biomaterial substance that can be applied in orthopaedics. In this study, the biocompatibility of this biomaterial was assessed using an in vitro technique. The cytotoxicity and genotoxicity effect of HA2 and HA3 against L929 fibroblast cell was evaluated using the MTT Assay and Alkaline Comet Assay respectively. Both HA2 and HA3 compound showed low cytotoxicity effect as determined using MTT Assay. Cells viability following 72 hours incubation at maximum concentration of both HA2 and HA3 (200 mg/ml) were 75.3 +/- 8.8% and 86.7 +/- 13.1% respectively. However, the cytotoxicity effect of ZnSO4.7H2O as a positive control showed an IC50 values of 46 mg/ml (160 microM). On the other hand, both HA2 and HA3 compound showed a slight genotoxicity effect as determined using the Alkaline Comet Assay following incubation at the concentration 200 mg/ml for 72 hours. This assay has been widely used in genetic toxicology to detect DNA strand breaks and alkali-labile site. The percentage of the cells with DNA damage for both substance was 27.7 +/- 1.3% and 15.6 +/- 1.0% for HA2 and HA3 respectively. Incubation of the cells for 24 hours with 38 microg/ml (IC25) of positive control showed an increase in percentage of cells with DNA damage (67.5 +/- 0.7%). In conclusion, our study indicated that both hydroxyapatite compounds showed a good biocompatibility in fibroblast cells.
    Matched MeSH terms: Biocompatible Materials/toxicity*
  6. Kannan TP, Nik Ahmad Shah NL, Azlina A, Samsudin AR, Narazah MY, Salleh M
    Med J Malaysia, 2004 May;59 Suppl B:168-9.
    PMID: 15468871
    The present study is aimed at finding the mutagenicity and cytotoxicity of dense form of synthetic hydroxyapatite (Source: School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia) in the blood of sheep. The biomaterial was implanted in the tibia of Malin, an indigenous sheep breed of Malaysia. Blood was collected from the sheep before implantation of the biomaterial, cultured and a karyological study was made. Six weeks after implantation, blood was collected from the same animal, cultured and screened for chromosome aberrations. The mitotic indices and karyological analysis indicated that the implantation of synthetic hydroxyapatite (dense form) did not produce any cytotoxicity or chromosome aberrations in the blood of sheep.
    Matched MeSH terms: Biocompatible Materials/toxicity*
  7. Azlina A, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:166-7.
    PMID: 15468870
    In Malaysia, the field of genomics in toxicology is still in infancy. The purpose of this study is to focus on the use of toxicogenomics for determination of gene expressions changes in cultured human fibroblast cells treated with genotoxicology free biomaterial (using Ames test), a locally produced hyroxyapatite. Dose and time response is similar to Ames test with time interval up to 21 days. mRNA is extracted, followed with RT-PCR and polyacrilamide gel electrophoresis. Changes of the gene expressions compared to the non-treated fibroblast mRNA would suggest some gene interactions in the molecule level associated with the exposure of the fibroblast cell line to the biomaterials. Further analysis (cloning & sequencing) shall be carried out to investigate the genes involved as simple changes might not signified toxicity.
    Matched MeSH terms: Biocompatible Materials/toxicity*
  8. Tan SA, Ahmad Fauzi MN, Luay BH, Radzali O
    Med J Malaysia, 2004 May;59 Suppl B:162-3.
    PMID: 15468868
    In this work, nanometer HA crystals have been synthesized via wet chemical precipitation and characterized. This research studies how key synthesis parameters affect the size and phase purity of the produced HA. Characterization work was carried out using X-ray powder diffraction method and scanning electron microscopy for phase identification and particle sizing, respectively.
    Matched MeSH terms: Biocompatible Materials/analysis; Biocompatible Materials/chemical synthesis*
  9. Khalid K
    Med J Malaysia, 2004 May;59 Suppl B:133-4.
    PMID: 15468854
    Matched MeSH terms: Biocompatible Materials*
  10. Idris B, Rusnah M, Reusmaazran YM, Rohaida CH
    Med J Malaysia, 2004 May;59 Suppl B:67-8.
    PMID: 15468822
    Matched MeSH terms: Biocompatible Materials/analysis; Biocompatible Materials/chemical synthesis*
  11. Ginebra MP, Aparicio C, Engel E, Navarro M, Javier Gil F, Planell JA
    Med J Malaysia, 2004 May;59 Suppl B:65-6.
    PMID: 15468821
    Matched MeSH terms: Biocompatible Materials/pharmacology*
  12. Lai KL, Roziyanna A, Ogunniyi DS, Zainal AM, Azlan AA
    Med J Malaysia, 2004 May;59 Suppl B:61-2.
    PMID: 15468819
    Various blend ratios of high-density polyethylene (HDPE) and ultra high molecular weight polyethylene (UHMWPE) were prepared with the objective of determining their suitability as biomaterials. In the unfilled state, a blend of 50/50 (HDPE/UHMWPE) ratio by weight was found to yield optimum properties in terms of processability and mechanical properties. Hydroxyapatite (HA) was compounded with the optimum blend ratio. The effects of HA loading, varied from 0 to 50wt% for both filled and unfilled blends were tested for mechanical properties. It was found that the inclusion of HA in the blend led to a remarkable improvement of mechanical properties compared to the unfilled blend. In order to improve the bonding between the polymer blend and the filler, the HA used was chemically treated with a coupling agent known as 3-(trimethoxysiyl) propyl methacrylate and the treated HA was mixed into the blend. The effect of mixing the blend with silane-treated HA also led to an overall improvement of mechanical properties.
    Matched MeSH terms: Biocompatible Materials/analysis; Biocompatible Materials/chemical synthesis*
  13. Hee SL, Nik Intan NI, Fazan F
    Med J Malaysia, 2004 May;59 Suppl B:77-8.
    PMID: 15468827
    There is a great demand of Hydroxyapatite (HA) material in Orthopaedics and Dental applications due to its similarity to human bone. However, the lack of availability and due to high import cost of this material in Malaysia, research in producing synthetic HA locally is therefore timely. The use of local resources as the raw materials for the production of HA is also desirable in reducing the overall cost of HA. In this study, two HA materials were synthesised from different starting precursors, i.e. commercial pure Ca(OH)2 (HAS) and Ca(OH)2 directly from a local natural limestone deposit (HAL). Whereas a commercially available HA "Captal 60" (HAC) was used as reference. The synthesised powders obtained were fired at 1000 degrees C and at 1250 degrees C. Characterisation evaluations on bulk properties were carried out using XRD, SEM-EDX, ICP and FTIR. The results indicate that both HAS and HAL are comparable to HAC even at 1000 degrees C. Thus, the local natural limestone can be used to form HA. However, the overall appearance of these materials are quite different (HAC - blue, HAS - greenish and HAL - light green). The reasons for this and the subsequent mechanical and bioactive effects of these materials are currently being investigated.
    Matched MeSH terms: Biocompatible Materials/analysis; Biocompatible Materials/chemical synthesis*
  14. Ambrosio L, Battista S, Borzacchiello A, Borselli C, Causa F, De Santis R, et al.
    Med J Malaysia, 2004 May;59 Suppl B:71-2.
    PMID: 15468824
    Matched MeSH terms: Biocompatible Materials*
  15. Fazan F, Shahida KB
    Med J Malaysia, 2004 May;59 Suppl B:69-70.
    PMID: 15468823
    The paper presents a method of producing synthetic Hydroxyapatite (HA) Ca10(PO4)6(OH)2 and other apatites for biological use by solid-state reaction. The solid-state reaction involves mix-grinding dry powders of beta-tricalcium phosphate powder (TCP) and either calcium hydroxide (Ca(OH)2) or calcium carbonate (CaCO3) or combination thereof, from pure commercial chemicals or derived from natural limestone or from seashells, of total calcium/phosphorus molar ratio between 1.5 to 2.0, to particle size of less than 10 microns, and firing the resultant powder to temperature between 600 degrees C - 1250 degrees C in atmosphere or in controlled atmospheric condition. The resultant apatites formed were characterised using XRD, SEM-EDX and FTIR. The presented reaction process was found to be much simpler compared to conventional methods of producing synthetic apatites since it involves only dry mix-grinding of the reactants before firing at high temperatures based on the required levels of purity. It can also produce synthetic apatites with good reproducibility in a shorter time. Thus the presented method has a great industrial value.
    Matched MeSH terms: Biocompatible Materials/analysis; Biocompatible Materials/chemical synthesis*
  16. Shah RK, Fahmi MN, Mat AH, Zainal AA
    Med J Malaysia, 2004 May;59 Suppl B:75-6.
    PMID: 15468826
    Hydroxyapatite (HA) has been earmarked as suitable for implantation within the human of its chemical makeup to human bone. In this paper, HA powders were synthesized via the precipitation method where phosphoric acid (H3PO4) was titrated into calcium hydroxide solution [Ca(OH)2]. Two parameters such as temperature and stirring rate were identified as factors that influenced the amount and purity of HA powder. Phase identification of the synthesized powder was done using X-Ray Diffraction (XRD). The results show that HA phase can be synthesized from this titration process of Ca(OH)2 and H3PO4 with yield amount of HA powder around 45 - 61 grams but with less than hundred percent purity. In order to study the effect of heat treatment to HA crystals structure, HA powder was calcined at 850 degrees C for 2 hours. It's found that the degree of crystallinity increases after calcination because of lattice expansion when the materials were heated at higher temperature
    Matched MeSH terms: Biocompatible Materials/chemical synthesis*
  17. Vert M
    Med J Malaysia, 2004 May;59 Suppl B:73-4.
    PMID: 15468825
    Matched MeSH terms: Biocompatible Materials*
  18. Nik Mohd Polo Kinin NM, Wan Mohd Arif WI, Zainal Arifm A
    Med J Malaysia, 2004 May;59 Suppl B:23-4.
    PMID: 15468800
    The appearance of dental porcelains is comparable to natural teeth. This study discusses the effect of Y2O3 addition to the fluorescent property of dental porcelains. The composition of dental porcelains contained Y2O3 as the fluorescent agent and base frit. The combinations of Y2O3 added consist of a series with 0.5, 1.0, 1.5, 2.0 and 2.5 wt% respectively, based on the total composition. In the extreme condition, fluorescent agents are added from 5.0 up to 10.0 wt%. In order to enhance the fluorescent property of dental porcelains, an opacifiying agent, cerium oxide (CeO2) was also added to dental porcelains composition. The fluorescent property was determined using Spectroline EF-1400C/F that emits 240 nm wavelength ultraviolet light. The microstructure was examined by Scanning Electron Microscope (SEM). The result shows that, the fluorescent properties displayed are similar to natural teeth when subjected to ultraviolet light. SEM micrograph was able to show the fluorescent agent dispersed in glass phase. Increasing additions of Y2O3 gave the fluorescent properties near to natural teeth.
    Matched MeSH terms: Biocompatible Materials*
  19. Doreya MI, Mona EW, Afaf ES, Hanan HB
    Med J Malaysia, 2004 May;59 Suppl B:21-2.
    PMID: 15468799
    The standard bioglass composition GS45 as well as with excess silica GS50 or with the addition of 5% titanium oxide GS45+Ti5, were prepared by the polymeric route. The different glass components were added to the formed polymer. Firing at 700 degrees C gave an amorphous product with microporous texture that readily crystallizes out at 900 degrees C. The prepared materials were highly porous with two modes of pore system micro-pores and macro-pores with a size ranging between 100 microm to 0.006 microm and a porosity reaching 73%. The measured bulk density was between 0.36 to 1.1g/cm3. The fired material preserved the former structure of the polymer precursor. Biocompatibility was verified in vitro and vivo. IR of the specimens previously immersed in SBF revealed the formation of apatite like layer. While the histology sections of implants in rate femurs showed new bone tissue or bone trabeculae after 21 days.
    Matched MeSH terms: Biocompatible Materials/chemical synthesis*
  20. Ismarul IN, Ishak Y, Ismail Z, Mohd Shalihuddin WM
    Med J Malaysia, 2004 May;59 Suppl B:57-8.
    PMID: 15468817
    Various proportions of chitosan/collagen films (70/30% to 95/05%) w/w were prepared and evaluated for its suitability as skin regenerating scaffold. Interactions between chitosan and collagen were studied using Fourier Transform Infrared spectroscopy (FTIR) and Differential Scanning Colorimetry (DSC). Scanning Electron Microscope (SEM) was used to investigate the morphology of the blend. Mechanical properties were evaluated using a Universal Testing Machine (UTM). The chitosan/collagen films were found to swell proportionally with time until it reaches equilibrium. FTIR spectroscopy indicated no chemical interaction between the components of the blends. DSC data indicated only one peak proving that these two materials are compatible at all proportions investigated. SEM micrographs also indicated good homogeneity between these two materials.
    Matched MeSH terms: Biocompatible Materials/analysis*
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