Displaying publications 221 - 240 of 294 in total

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  1. Canfield PJ, Best FG, Fairburn AJ, Purdie J, Gilham M
    Aust Vet J, 1984 Mar;61(3):89-93.
    PMID: 6743148
    Blood samples were collected from 24 immature male, 55 immature female and 99 mature female water buffalo kept at an experimental farm in the Northern Territory. Haematological analysis was performed on blood collected in dipotassium--ethylene diamine tetra acetic acid while biochemical analysis was performed on serum and plasma (for glucose) samples. Haematological values of mature buffalo were similar to those recorded for swamp buffalo in Malaysia. Blood cell appearances were similar to those reported for adult Indian river buffalo though values recorded for red cell components were higher. Statistical analysis revealed no significant differences between immature male and female buffalo. Red cell components, eosinophils, total plasma and serum proteins, albumin, gamma globulins, inorganic phosphate and the enzyme gamma-glutamyl transferase were significantly higher for mature female buffalo when compared to immature females. Reasons for the differences were not fully determined but the effect of age and nutritional status in combination with a variable period of domestication were considered.
    Matched MeSH terms: Phosphates/blood
  2. Wong YF, Saad B, Makahleh A
    J Chromatogr A, 2013 May 17;1290:82-90.
    PMID: 23578483 DOI: 10.1016/j.chroma.2013.03.014
    A capillary electrophoresis (CE)-capacitively coupled contactless conductivity detection (C(4)D) method for the simultaneous separation of eleven underivatized fatty acids (FAs), namely, lauric, myristic, tridecanoic (internal standard), pentadecanoic, palmitic, stearic, oleic, elaidic, linoleic, linolenic and arachidic acids is described. The separation was carried out in normal polarity mode at 20 °C, 30 kV and using hydrodynamic injection (50 mbar for 1 s). The separation was achieved in a bare fused-silica capillary (70 cm × 75 μm i.d.) using a background electrolyte of methyl-β-cyclodextrin (~6 mM) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (~8 mM) dissolved in a mixture of Na2HPO4/KH2PO4 (5 mM, pH 7.4):ACN:MeOH:n-octanol (3:4:2.5:0.5, v/v/v/v). C(4)D parameters were set at fixed amplitude of 100 V and frequency of 1000 kHz. The developed method was validated. Calibration curves of the ten FAs were well correlated (r(2)>0.99) within the range of 5-250 μg mL(-1) for lauric acid, and 3-250 μg mL(-1) for the other FAs. The method was simple and sensitive with detection limits (S/N=3) of 0.9-1.9 μg mL(-1) and good relative standard deviations of intra- and inter-day for migration times and peak areas (≤9.7%) were achieved. The method was applied to the determination of FAs in margarine samples. The proposed method offers distinct advantages over the GC and HPLC methods, especially in terms of simplicity (without derivatization) and sensitivity.
    Matched MeSH terms: Phosphates/chemistry
  3. Ong YH, Chua AS, Lee BP, Ngoh GC
    Water Sci Technol, 2013;67(2):340-6.
    PMID: 23168633 DOI: 10.2166/wst.2012.552
    To date, little information is known about the operation of the enhanced biological phosphorus removal (EBPR) process in tropical climates. Along with the global concerns on nutrient pollution and the increasing array of local regulatory requirements, the applicability and compliance accountability of the EBPR process for sewage treatment in tropical climates is being evaluated. A sequencing batch reactor (SBR) inoculated with seed sludge from a conventional activated sludge (CAS) process was successfully acclimatized to EBPR conditions at 28 °C after 13 days' operation. Enrichment of Candidatus Accumulibacter phosphatis in the SBR was confirmed through fluorescence in situ hybridization (FISH). The effects of operational pH and influent C:P ratio on EBPR were then investigated. At pH 7 or pH 8, phosphorus removal rates of the EBPR processes were relatively higher when operated at C:P ratio of 3 than C:P ratio of 10, with 0.019-0.020 and 0.011-0.012 g-P/g-MLVSS•day respectively. One-year operation of the 28 °C EBPR process at C:P ratio of 3 and pH 8 demonstrated stable phosphorus removal rate of 0.020 ± 0.003 g-P/g-MLVSS•day, corresponding to effluent with phosphorus concentration <0.5 mg/L. This study provides the first evidence on good EBPR activity at relatively high temperature, indicating its applicability in a tropical climate.
    Matched MeSH terms: Phosphates/analysis
  4. Foo KY, Lee LK, Hameed BH
    Bioresour Technol, 2013 Apr;134:166-72.
    PMID: 23500574 DOI: 10.1016/j.biortech.2013.01.139
    This study evaluates the sugarcane bagasse derived activated carbon (SBAC) prepared by microwave heating for the adsorptive removal of ammonical nitrogen and orthophosphate from the semi-aerobic landfill leachate. The physical and chemical properties of SBAC were examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The effects of adsorbent dosage, contact time and solution pH on the adsorption performance were investigated in a batch mode study at 30°C. Equilibrium data were favorably described by the Langmuir isotherm model, with a maximum monolayer adsorption capacity for ammonical nitrogen and orthophosphate of 138.46 and 12.81 mg/g, respectively, while the adsorption kinetic was best fitted to the pseudo-second-order kinetic model. The results illustrated the potential of sugarcane bagasse derived activated carbon for the adsorptive treatment of semi-aerobic landfill leachate.
    Matched MeSH terms: Phosphates/isolation & purification
  5. Abdul Gafor AH, Saidin R, Loo CY, Mohd R, Zainudin S, Shah SA, et al.
    Nephrology (Carlton), 2009 Aug;14(5):488-92.
    PMID: 19298641 DOI: 10.1111/j.1440-1797.2008.01058.x
    Secondary hyperparathyroidism (SHPT) is common among haemodialysis patients. Intensive treatment with calcitriol is often complicated by hypercalcaemia, hyperphosphataemia and elevated calcium phosphorus (Ca X PO(4)) product. Paricalcitol is a vitamin D analogue developed to overcome some of the limitations of calcitriol therapy. The study objectives were to compare the response of intact parathyroid hormone (iPTH) and the incidence of hypercalcaemia, hyperphosphataemia and elevated Ca X PO(4) product in patients with severe SHPT treated with either i.v. calcitriol or i.v. paricalcitol.
    Matched MeSH terms: Phosphates/blood
  6. Shukor MY, Ahmad SA, Nadzir MM, Abdullah MP, Shamaan NA, Syed MA
    J Appl Microbiol, 2010 Jun;108(6):2050-8.
    PMID: 19968732 DOI: 10.1111/j.1365-2672.2009.04604.x
    To isolate and characterize a potent molybdenum-reducing bacterium.
    Matched MeSH terms: Phosphates/metabolism
  7. Al-Jubouri MA, Inkster GD, Nee PA, Andrews FJ
    Ann. Clin. Biochem., 2006 Jul;43(Pt 4):323-5.
    PMID: 16824287 DOI: 10.1258/000456306777695681
    A 35-year-old Malaysian man presented with rapid onset of flaccid quadriparesis associated with nausea and vomiting. General blood tests revealed severe hypokalaemia (serum potassium 1.5 mmol/L) and hypophosphataemia (serum phosphate 0.29 mmol/L) as a potential cause of the flaccid paralysis. Arterial blood gases showed mixed acid base disturbance of respiratory alkalosis and metabolic acidosis with hyperlactataemia. Thyrotoxic periodic paralysis (TPP) was suspected as the underlying cause of this presentation and thyroid function tests showed severe hyperthyroid results (free T4 > 77.2 pmol/L, free T3 19.3 pmol/L, thyroid-stimulating hormone [TSH] < 0.05 mIU/L). Treatment with intravenous potassium and phosphate infusion and oral propranolol resulted in rapid resolution of his symptoms. A discussion of the clinical and pathophysiological features and treatment of TPP (a very rare encounter in UK clinical practice) is presented, and to our knowledge associated hyperlactataemia has not been previously described.
    Matched MeSH terms: Phosphates/therapeutic use
  8. Chew KK, Low KL, Sharif Zein SH, McPhail DS, Gerhardt LC, Roether JA, et al.
    J Mech Behav Biomed Mater, 2011 Apr;4(3):331-9.
    PMID: 21316621 DOI: 10.1016/j.jmbbm.2010.10.013
    This paper presents the development of novel alternative injectable calcium phosphate cement (CPC) composites for orthopaedic applications. The new CPC composites comprise β-tri-calcium phosphate (β-TCP) and di-calcium phosphate anhydrous (DCPA) mixed with bovine serum albumin (BSA) and incorporated with multi-walled carbon nanotubes (MWCNTs) or functionalized MWCNTs (MWCNTs-OH and MWCNTs-COOH). Scanning electron microscopy (SEM), compressive strength tests, injectability tests, Fourier transform infrared spectroscopy and X-ray diffraction were used to evaluate the properties of the final products. Compressive strength tests and SEM observations demonstrated particularly that the concomitant admixture of BSA and MWCNT improved the mechanical properties, resulting in stronger CPC composites. The presence of MWCNTs and BSA influenced the morphology of the hydroxyapatite (HA) crystals in the CPC matrix. BSA was found to act as a promoter of HA growth when bounded to the surface of CPC grains. MWCNT-OH-containing composites exhibited the highest compressive strengths (16.3 MPa), being in the range of values for trabecular bone (2-12 MPa).
    Matched MeSH terms: Calcium Phosphates/chemistry*
  9. Hashim N, Sabudin S, Ibrahim S, Zin NM, Bakar SH, Fazan F
    Med J Malaysia, 2004 May;59 Suppl B:103-4.
    PMID: 15468839
    Hydroxyapatite (HA; Ca10(PO4)6(OH)2), is one of the significant implant materials used in Orthopaedics and Dental applications. However, synthetically produced HA may not be stable under ionic environment, which it will unavoidably encounter during its applications. In this paper, the in vitro effects of three HA materials derived from different resources, i.e. commercial HA (HAC), synthesised HA from pure chemicals (HAS) and synthesised HA from kapur sireh; derived traditionally from natural limestone (HAK), were studied. The HA disc samples were prepared and immersed in simulated body fluid (SBF) for 31-day period. The evaluation conducted focuses on the changes of the pH and the Calcium ion (Ca-ion) and Phosphate ion (P-ion) concentrations in the SBF solution, as well as the XRD and SEM data representing the reactions on the HA materials. From the XRD, it was found that HAK has the smallest crystallite sizes, which in turn affect the pH of the SBF during immersion. The Ca and P-ion concentrations generally decrease over time at different rates for different HA. Upon 1-day immersion in SBF, apatite growth was observed onto all three surfaces, which became more pronounced after 3-day immersion. However, the appetites formed were observed to be different in shapes and sizes. The reasons for the difference in the apatite-crystals and their subsequent effects on cells are still being investigated.
    Matched MeSH terms: Phosphates/pharmacology*
  10. Lim SL, Chu WL, Phang SM
    Bioresour Technol, 2010 Oct;101(19):7314-22.
    PMID: 20547057 DOI: 10.1016/j.biortech.2010.04.092
    The potential application of Chlorella vulgaris UMACC 001 for bioremediation of textile wastewater (TW) was investigated using four batches of cultures in high rate algae ponds (HRAP) containing textile dye (Supranol Red 3BW) or TW. The biomass attained ranged from 0.17 to 2.26 mg chlorophyll a/L while colour removal ranged from 41.8% to 50.0%. There was also reduction of NH(4)-N (44.4-45.1%), PO(4)-P (33.1-33.3%) and COD (38.3-62.3%) in the TW. Supplementation of the TW with nutrients of Bold's Basal Medium (BBM) increased biomass production but did not improve colour removal or reduction of pollutants. The mechanism of colour removal by C. vulgaris is biosorption, in accordance with both the Langmuir and Freundlich models. The HRAP using C. vulgaris offers a good system for the polishing of TW before final discharge.
    Matched MeSH terms: Phosphates/analysis
  11. Shukor MY, Habib SH, Rahman MF, Jirangon H, Abdullah MP, Shamaan NA, et al.
    Appl Biochem Biotechnol, 2008 Apr;149(1):33-43.
    PMID: 18350385 DOI: 10.1007/s12010-008-8137-z
    A molybdate-reducing bacterium has been locally isolated. The bacterium reduces molybdate or Mo(6+) to molybdenum blue (molybdate oxidation states of between 5+ and 6+). Different carbon sources such as acetate, formate, glycerol, citric acid, lactose, fructose, glucose, mannitol, tartarate, maltose, sucrose, and starch were used at an initial concentration of 0.2% (w/v) in low phosphate media to study their effect on the molybdate reduction efficiency of bacterium. All of the carbon sources supported cellular growth, but only sucrose, maltose, glucose, and glycerol (in decreasing order) supported molybdate reduction after 24 h of incubation. Optimum concentration of sucrose for molybdate reduction is 1.0% (w/v) after 24 h of static incubation. Ammonium sulfate, ammonium chloride, valine, OH-proline, glutamic acid, and alanine (in the order of decreasing efficiency) supported molybdate reduction with ammonium sulfate giving the highest amount of molybdenum blue after 24 h of incubation at 0.3% (w/v). The optimum molybdate concentration that supports molybdate reduction is between 15 and 25 mM. Molybdate reduction is optimum at 35 degrees C. Phosphate at concentrations higher than 5 mM strongly inhibits molybdate reduction. The molybdenum blue produced from cellular reduction exhibits a unique absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. The isolate was tentatively identified as Serratia marcescens Strain Dr.Y6 based on carbon utilization profiles using Biolog GN plates and partial 16s rDNA molecular phylogeny.
    Matched MeSH terms: Phosphates/pharmacology
  12. Sim CH, Yusoff MK, Shutes B, Ho SC, Mansor M
    J Environ Manage, 2008 Jul;88(2):307-17.
    PMID: 17467147
    Putrajaya Wetlands in Malaysia, a 200ha constructed wetland system consisting of 24 cells, was created in 1997-1998 to treat surface runoff caused by development and agricultural activities from an upstream catchment before entering Putrajaya Lake (400ha). It was designed for stormwater treatment, flood control and amenity use. The water quality improvement performance of a section of the wetland cells is described. The nutrient removal performance was 82.11% for total nitrogen, 70.73% for nitrate-nitrogen and 84.32% for phosphate, respectively, along six wetland cells from Upper North UN6 to UN1 from April to December 2004. Nutrient removal in pilot scale tank systems, simulating a constructed wetland and planted with examples of common species at Putrajaya, the Common Reed Phragmites karka and Tube Sedge Lepironia articulata, and the capacity of these species to retain nutrients in above and below-ground plant biomass and substrate is reported. The uptake of nutrients by the Common Reed and Tube Sedge from the pilot tank system was 42.1% TKN; 28.9% P and 17.4% TKN; 26.1% P, respectively. The nutrient uptake efficiency of the Common Reed was higher in above-ground than in below-ground tissue. The results have implications for plant species selection in the design of constructed wetlands in Malaysia and for optimizing the performance of these systems.
    Matched MeSH terms: Phosphates/chemistry
  13. Panhwar QA, Naher UA, Shamshuddin J, Jusop S, Othman R, Latif MA, et al.
    PLoS One, 2014;9(10):e97241.
    PMID: 25285745 DOI: 10.1371/journal.pone.0097241
    A study was conducted to determine the total microbial population, the occurrence of growth promoting bacteria and their beneficial traits in acid sulfate soils. The mechanisms by which the bacteria enhance rice seedlings grown under high Al and low pH stress were investigated. Soils and rice root samples were randomly collected from four sites in the study area (Kelantan, Malaysia). The topsoil pH and exchangeable Al ranged from 3.3 to 4.7 and 1.24 to 4.25 cmol(c) kg(-1), respectively, which are considered unsuitable for rice production. Total bacterial and actinomycetes population in the acidic soils were found to be higher than fungal populations. A total of 21 phosphate-solubilizing bacteria (PSB) including 19 N2-fixing strains were isolated from the acid sulfate soil. Using 16S rRNA gene sequence analysis, three potential PSB strains based on their beneficial characteristics were identified (Burkholderia thailandensis, Sphingomonas pituitosa and Burkholderia seminalis). The isolated strains were capable of producing indoleacetic acid (IAA) and organic acids that were able to reduce Al availability via a chelation process. These PSB isolates solubilized P (43.65%) existing in the growth media within 72 hours of incubation. Seedling of rice variety, MR 219, grown at pH 4, and with different concentrations of Al (0, 50 and 100 µM) was inoculated with these PSB strains. Results showed that the bacteria increased the pH with a concomitant reduction in Al concentration, which translated into better rice growth. The improved root volume and seedling dry weight of the inoculated plants indicated the potential of these isolates to be used in a bio-fertilizer formulation for rice cultivation on acid sulfate soils.
    Matched MeSH terms: Phosphates/chemistry*
  14. Ng MH, Duski S, Tan KK, Yusof MR, Low KC, Rose IM, et al.
    Biomed Res Int, 2014;2014:345910.
    PMID: 25165699 DOI: 10.1155/2014/345910
    Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB) to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC) and partially demineralized allogeneic bone block (ALLO). Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32), MIC (1.28 ± 0.24), and negative controls (0). Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1%) compared to ALLO (5% ± 2.5%) and MIC (26% ± 5.2%). Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa) compared to those treated with ALLO (15.15 ± 3.57 MPa) and MIC (23.28 ± 6.14 MPa). In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function.
    Matched MeSH terms: Calcium Phosphates/administration & dosage*
  15. Sarjit A, Dykes GA
    Int J Food Microbiol, 2015 Jun 16;203:63-9.
    PMID: 25791251 DOI: 10.1016/j.ijfoodmicro.2015.02.026
    Little work has been reported on the use of commercial antimicrobials against foodborne pathogens on duck meat. We investigated the effectiveness of trisodium phosphate (TSP) and sodium hypochlorite (SH) as antimicrobial treatments against Campylobacter and Salmonella on duck meat under simulated commercial water chilling conditions. The results were compared to the same treatments on well-studied chicken meat. A six strain Campylobacter or Salmonella cocktail was inoculated (5 ml) at two dilution levels (10(4) and 10(8) cfu/ml) onto 25 g duck or chicken meat with skin and allowed to attach for 10 min. The meat was exposed to three concentrations of pH adjusted TSP (8, 10 and 12% (w/v), pH 11.5) or SH (40, 50 and 60 ppm, pH 5.5) in 30 ml water under simulated spin chiller conditions (4 °C, agitation) for 10 min. In a parallel experiment the meat was placed in the antimicrobial treatments before inoculation and bacterial cocktails were added to the meat after the antimicrobial solution was removed while all other parameters were maintained. Untreated controls and controls using water were included in all experiments. Bacterial numbers were determined on Campylobacter blood-free selective agar and Mueller Hinton agar or xylose deoxycholate agar and tryptone soya agar using the thin agar layer method for Campylobacter and Salmonella, respectively. All TSP concentrations significantly (p<0.05) reduced numbers of Campylobacter (~1.2-6.4 log cfu/cm(2)) and Salmonella (~0.4-6.6 log cfu/cm(2)) on both duck and chicken meat. On duck meat, numbers of Campylobacter were less than the limit of detection at higher concentrations of TSP and numbers of Salmonella were less than the limit of detection at all concentrations of TSP except one. On chicken meat, numbers of Campylobacter and Salmonella were less than the limit of detection only at the lower inoculum level and higher TSP concentrations. By contrast only some of the concentrations of SH significantly (p<0.05) reduced numbers of Campylobacter and Salmonella (~0.2-1.5 log cfu/cm(2)) on both duck and chicken meats. None of the SH treatments resulted in numbers of either pathogen being less than limit of detection. Results indicate that chicken meat has the ability to effectively protect Campylobacter and Salmonella against the impact of trisodium phosphate and sodium hypochlorite while duck meat does not. This study suggests that trisodium phosphate has a strong potential for application in a commercial poultry processing to reduce Campylobacter and Salmonella specifically on duck meat.
    Matched MeSH terms: Phosphates/pharmacology*
  16. Halmi MI, Zuhainis SW, Yusof MT, Shaharuddin NA, Helmi W, Shukor Y, et al.
    Biomed Res Int, 2013;2013:384541.
    PMID: 24383052 DOI: 10.1155/2013/384541
    Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS-) degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v), between 25 and 30 mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5 mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3 g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant.
    Matched MeSH terms: Phosphates/metabolism
  17. Leng KM, Vijayarathna S, Jothy SL, Sasidharan S, Kanwar JR
    Biomed Pharmacother, 2018 Jan;97:26-37.
    PMID: 29080455 DOI: 10.1016/j.biopha.2017.10.121
    Lactoferrin has been known to have antimicrobial properties. This research was conducted to investigate the toxicity of Alginate/EUDRAGIT® S 100-enclosed chitosan-calcium phosphate-loaded Fe-bLf nanocapsules (NCs) by in vitro and in vivo assays. Brine shrimp lethality assay showed that the LC50 value of NCs was more than 1mg/mL which indicated that NCs was not toxic to Brine shrimp. However, the LC50 values for the positive control potassium dichromate at 24h is 64.15μg/mL, which was demostrated the toxic effect against the brine shrimp. MTT cytotoxicity assay also revealed that NCs was not toxic against non-cancerous Vero cell line with IC50 values of 536μg/mL. Genotoxicity studies by comet assay on Vero cells revealed that NCs exerted no significant genotoxic at 100μg/mL without tail or shorter comet tail. Allium cepa root assay carried out at 125, 250, 500 and 1000μg/mL for 24h revealed that the NCs was destitute of significant genotoxic effect under experimental conditions. The results show that there is no significant difference (p>0.05) in mitotic index between the deionized water and NCs treated Allium cepa root tip cells. In conclusion, no toxicity was observed in NCs in this study. Therefore, nontoxic NCs has the good potential to develop as a therapeutic agent.
    Matched MeSH terms: Calcium Phosphates/administration & dosage; Calcium Phosphates/toxicity*
  18. Touri M, Moztarzadeh F, Osman NAA, Dehghan MM, Mozafari M
    Mater Sci Eng C Mater Biol Appl, 2018 Mar 01;84:236-242.
    PMID: 29519434 DOI: 10.1016/j.msec.2017.11.037
    Tissue engineering scaffolds with oxygen generating elements have shown to be able to increase the level of oxygen and cell survivability in specific conditions. In this study, biphasic calcium phosphate (BCP) scaffolds with the composition of 60% hydroxyapatite (HA) and 40% beta-tricalcium phosphate (β-TCP), which have shown a great potential for bone tissue engineering applications, were fabricated by a direct-write assembly (robocasting) technique. Then, the three-dimensional (3D)-printed scaffolds were coated with different ratios of an oxygen releasing agent, calcium peroxide (CPO), which encapsulated within a polycaprolactone (PCL) matrix through dip-coating, and used for in situ production of oxygen in the implanted sites. The structure, composition and morphology of the prepared scaffolds were characterized by different techniques. The oxygen release kinetics and biological investigations of the scaffolds were also studied in vitro. The results showed that oxygen release behaviour was sustained and dependant on the concentration of CPO encapsulated in the PCL coating matrix. It was also demonstrated that the coated scaffolds, having 3% CPO in the coating system, could provide a great potential for promoting bone ingrowth with improving osteoblast cells viability and proliferation under hypoxic conditions. The findings indicated that the prepared scaffolds could play a significant role in engineering of large bone tissue implants with limitations in oxygen diffusion.
    Matched MeSH terms: Calcium Phosphates/chemistry*
  19. Lulu GA, Karunanidhi A, Mohamad Yusof L, Abba Y, Mohd Fauzi F, Othman F
    Ann Clin Microbiol Antimicrob, 2018 Dec 28;17(1):46.
    PMID: 30593272 DOI: 10.1186/s12941-018-0296-3
    BACKGROUND: Osteomyelitis is an acute or chronic inflammatory process of the bone following infection with pyogenic organisms like Staphylococcus aureus. Tobramycin (TOB) is a promising aminoglycoside antibiotic used to treat various bacterial infections, including S. aureus. The aim of this study was to investigate the efficacy of tobramycin-loaded calcium phosphate beads (CPB) in a rabbit osteomyelitis model.

    METHODS: Tobramycin (30 mg/mL) was incorporated into CPB by dipping method and the efficacy of TOB-loaded CPB was studied in a rabbit osteomyelitis model. For juxtaposition, CPB with and without TOB were prepared. Twenty-five New Zealand white rabbits were grouped (n = 5) as sham (group 1), TOB-loaded CPB without S. aureus (group 2), S. aureus only (group 3), S. aureus + CPB (group 4), and S. aureus + TOB-loaded CPB (group 5). Groups infected with S. aureus followed by CPB implantation were immediately subjected to surgery at the mid-shaft of the tibia. After 28 days post-surgery, all rabbits were euthanized and the presence or absence of chronic osteomyelitis and the extent of architectural destruction of the bone were assessed by radiology, bacteriology and histological studies.

    RESULTS: Tobramycin-loaded CPB group potentially inhibited the growth of S. aureus causing 3.2 to 3.4 log10 reductions in CFU/g of bone tissue compared to the controls. Untreated groups infected with S. aureus showed signs of chronic osteomyelitis with abundant bacterial growth and alterations in bone architecture. The sham group and TOB-loaded CPB group showed no evidence of bacterial growth.

    CONCLUSIONS: TOB-incorporated into CPB for local bone administration was proven to be more successful in increasing the efficacy of TOB in this rabbit osteomyelitis model and hence could represent a good alternative to other formulations used in the treatment of osteomyelitis.

    Matched MeSH terms: Calcium Phosphates/chemistry*
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