Displaying publications 1 - 20 of 38 in total

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  1. Ab Halim MH, Nor Anuar A, Azmi SI, Jamal NS, Wahab NA, Ujang Z, et al.
    Bioresour Technol, 2015 Jun;185:445-9.
    PMID: 25851807 DOI: 10.1016/j.biortech.2015.03.024
    With inoculum sludge from a conventional activated sludge wastewater treatment plant, three sequencing batch reactors (SBRs) fed with synthetic wastewater were operated at different high temperatures (30, 40 and 50±1°C) to study the formation of aerobic granular sludge (AGS) for simultaneous organics and nutrients removal with a complete cycle time of 3h. The AGS were successfully cultivated with influent loading rate of 1.6CODg(Ld)(-1). The COD/N ratio of the influent wastewater was 8. The results revealed that granules developed at 50°C have the highest average diameter, (3.36mm) with 98.17%, 94.45% and 72.46% removal efficiency observed in the system for COD, ammonia and phosphate, respectively. This study also demonstrated the capabilities of AGS formation at high temperatures which is suitable to be applied for hot climate conditions.
    Matched MeSH terms: Phosphates/chemistry
  2. Ab Halim MH, Nor Anuar A, Abdul Jamal NS, Azmi SI, Ujang Z, Bob MM
    J Environ Manage, 2016 Dec 15;184(Pt 2):271-280.
    PMID: 27720606 DOI: 10.1016/j.jenvman.2016.09.079
    The effect of temperature on the efficiency of organics and nutrients removal during the cultivation of aerobic granular sludge (AGS) in biological treatment of synthetic wastewater was studied. With this aim, three 3 L sequencing batch reactors (SBRs) with influent loading rate of 1.6 COD g (L d)(-1) were operated at different high temperatures (30, 40 and 50 °C) for simultaneous COD, phosphate and ammonia removal at a complete cycle time of 3 h. The systems were successfully started up and progressed to steady state at different cultivation periods. The statistical comparison of COD, phosphate and ammonia for effluent from the three SBRs revealed that there was a significant difference between groups of all the working temperatures of the bioreactors. The AGS cultivated at different high temperatures also positively correlated with the accumulation of elements including carbon, oxygen, phosphorus, silicon, iron, aluminium, calcium and magnesium that played important roles in the granulation process.
    Matched MeSH terms: Phosphates/chemistry
  3. Abdullah AM, Rahim TNAT, Hamad WNFW, Mohamad D, Akil HM, Rajion ZA
    Dent Mater, 2018 11;34(11):e309-e316.
    PMID: 30268678 DOI: 10.1016/j.dental.2018.09.006
    OBJECTIVE: To compare the mechanical and biological properties of newly developed hybrid ceramics filled and unfilled polyamide 12 (PA 12) for craniofacial reconstruction via a fused deposition modelling (FDM) framework.

    METHODS: 15wt% of zirconia (ZrO2) as well as 30, 35, and 40wt% of beta-tricalcium phosphate (β-TCP) were compounded with PA 12, followed by the fabrication of filament feedstocks using a single screw extruder. The fabricated filament feedstocks were used to print the impact specimens. The melt flow rate, tensile properties of fabricated filament feedstocks, and 3D printed impact properties of the specimens were assessed using melt flow indexer, universal testing machine, and Izod pendulum tester, respectively. The microstructure of selected filament feedstocks and broken impact specimens were analysed using a field emission scanning electron microscope and universal testing machine. Human periodontal ligament fibroblast cells (HPdLF) were used to evaluate the cytotoxicity of the materials by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromid) (MTT) assay.

    RESULTS: Hybrid ceramics filled PA 12 indicated sufficient flowability for FDM 3D printing. The tensile strength of hybrid ceramics filled PA 12 filament feedstocks slightly reduced as compared to unfilled PA 12. However, the tensile modulus and impact strength of hybrid ceramics filled PA 12 increased by 8%-31% and 98%-181%, respectively. A significant increase was also detected in the cell viability of the developed composites at concentrations of 12.5, 25, 50 and 100mg/ml.

    SIGNIFICANCE: The newly developed hybrid ceramics filled PA 12 filament feedstock with improved properties is suitable for an FDM-based 3D printer, which enables the creation of patient-specific craniofacial implant at a lower cost to serve low-income patients.

    Matched MeSH terms: Calcium Phosphates/chemistry
  4. Abdullah AM, Mohamad D, Rahim TNAT, Akil HM, Rajion ZA
    Mater Sci Eng C Mater Biol Appl, 2019 Jun;99:719-725.
    PMID: 30889745 DOI: 10.1016/j.msec.2019.02.007
    This study reports the influence of ZrO2/β-TCP hybridization on the thermal, mechanical, and physical properties of polyamide 12 composites to be suited for bone replacement. Amount of 15 wt% of nano-ZrO2 along with 5,10,15,20 and 25 wt% of micro-β-TCP was compounded with polyamide 12 via a twin-screw extruder. The hybrid ZrO2/β-TCP filled polyamide 12 exhibited higher thermal, mechanical and physical properties in comparison to unfilled polyamide 12 at certain filler loading; which is attributed to the homogenous dispersion of ZrO2/β-TCP fillers particle in polyamide 12 matrix. The hybrid ZrO2/β-TCP filled PA 12 demonstrated an increment of tensile strength by up to 1%, tensile modulus of 38%, flexural strength of 15%, flexural modulus of 45%, and surface roughness value of 93%, as compared to unfilled PA 12. With enhanced thermal, mechanical and physical properties, the newly developed hybrid ZrO2/β-TCP filled PA 12 could be potentially utilized for bone replacement.
    Matched MeSH terms: Calcium Phosphates/chemistry
  5. Anne-Marie K, Yee W, Loh SH, Aziz A, Cha TS
    Appl Biochem Biotechnol, 2020 Apr;190(4):1438-1456.
    PMID: 31782088 DOI: 10.1007/s12010-019-03182-z
    In this study, the effects of limited and excess phosphate on biomass content, oil content, fatty acid profile and the expression of three fatty acid desaturases in Messastrum gracile SE-MC4 were determined. It was found that total biomass (0.67-0.83 g L-1), oil content (30.99-38.08%) and the duration for cells to reach stationary phase (25-27 days) were not considerably affected by phosphate limitation. However, excess phosphate slightly reduced total biomass and oil content to 0.50 g L-1 and 25.36% respectively. The dominant fatty acids in M. gracile, pamitic acid (C16:0) and oleic acid (C18:1) which constitute more than 81% of the total fatty acids remained relatively high and constant across all phosphate concentrations. Reduction of phosphate concentration to 25% and below significantly increased total MUFA, whereas increasing phosphate concentration to ≥ 50% and ≥ 100% significantly increased total SFA and PUFA content respectively. The expression of omega-3 fatty acid desaturase (ω-3 FADi1, ω-3 FADi2) and omega-6 fatty acid desaturase (ω-6 FAD) was increased under phosphate limitation, especially at ≤ 12.5% phosphate, whereas levels of streoyl-ACP desaturase (SAD) transcripts were relatively unchanged across all phosphate concentrations. The first isoform of ω-3 FAD (ω-3 FADi) displayed a binary upregulation under limited (≤ 12.5%) and excess (200%) phosphate. The expression of ω-6 FAD, ω-3 FAD and SAD were inconsistent with the accumulation of oleic acid (C18:1), linoleic acid (C18:2) and alpha-linolenic acid (C18:3), suggesting that these genes may be regulated indirectly by phosphate availability via post-transcriptional or post-translational mechanisms.
    Matched MeSH terms: Phosphates/chemistry*
  6. Bang LT, Ramesh S, Purbolaksono J, Long BD, Chandran H, Ramesh S, et al.
    Biomed Mater, 2015 Aug;10(4):045011.
    PMID: 26225725 DOI: 10.1088/1748-6041/10/4/045011
    Interconnected porous tricalcium phosphate ceramics are considered to be potential bone substitutes. However, insufficient mechanical properties when using tricalcium phosphate powders remain a challenge. To mitigate these issues, we have developed a new approach to produce an interconnected alpha-tricalcium phosphate (α-TCP) scaffold and to perform surface modification on the scaffold with a composite layer, which consists of hybrid carbonate apatite / poly-epsilon-caprolactone (CO3Ap/PCL) with enhanced mechanical properties and biological performance. Different CO3Ap combinations were tested to evaluate the optimal mechanical strength and in vitro cell response of the scaffold. The α-TCP scaffold coated with CO3Ap/PCL maintained a fully interconnected structure with a porosity of 80% to 86% and achieved an improved compressive strength mimicking that of cancellous bone. The addition of CO3Ap coupled with the fully interconnected microstructure of the α-TCP scaffolds coated with CO3Ap/PCL increased cell attachment, accelerated proliferation and resulted in greater alkaline phosphatase (ALP) activity. Hence, our bone substitute exhibited promising potential for applications in cancellous bone-type replacement.
    Matched MeSH terms: Calcium Phosphates/chemistry*
  7. Baradaran S, Moghaddam E, Nasiri-Tabrizi B, Basirun WJ, Mehrali M, Sookhakian M, et al.
    Mater Sci Eng C Mater Biol Appl, 2015 Apr;49:656-668.
    PMID: 25686995 DOI: 10.1016/j.msec.2015.01.050
    The effect of the addition of an ionic dopant to calcium phosphates for biomedical applications requires specific research due to the essential roles played in such processes. In the present study, the mechanical and biological properties of Ni-doped hydroxyapatite (HA) and Ni-doped HA mixed with graphene nanoplatelets (GNPs) were evaluated. Ni (3wt.% and 6wt.%)-doped HA was synthesized using a continuous precipitation method and calcined at 900°C for 1h. The GNP (0.5-2wt.%)-reinforced 6% Ni-doped HA (Ni6) composite was prepared using rotary ball milling for 15h. The sintering process was performed using hot isostatic pressing at processing conditions of 1150°C and 160MPa with a 1-h holding time. The results indicated that the phase compositions and structural features of the products were noticeably affected by the Ni and GNPs. The mechanical properties of Ni6 and 1.5Ni6 were increased by 55% and 75% in hardness, 59% and 163% in fracture toughness and 120% and 85% in elastic modulus compared with monolithic HA, respectively. The in-vitro biological behavior was investigated using h-FOB osteoblast cells in 1, 3 and 5days of culture. Based on the osteoblast results, the cytotoxicity of the products was indeed affected by the Ni doping. In addition, the effect of GNPs on the growth and proliferation of osteoblast cells was investigated in Ni6 composites containing different ratios of GNPs, where 1.5wt.% was the optimum value.
    Matched MeSH terms: Calcium Phosphates/chemistry*
  8. Chahal S, Chalal S, Fathima SJ, Yusoff MB
    Biomed Mater Eng, 2014;24(1):799-806.
    PMID: 24211966 DOI: 10.3233/BME-130871
    In this study, randomly oriented hydroxyethyl cellulose/polyvinyl alcohol (HEC/PVA) nanofibers were fabricated by electrospinning. The blend solutions of HEC/PVA with different weight ratio of HEC to PVA were prepared using water as solvent to fabricate nanofibers. These nanofibrous scaffolds were coated with bone-like apatite by immersing into 10x simulated body fluid (SBF) for different time periods. The morphology and structure of the nanofibers were characterized by SEM, FTIR and DSC. FESEM-EDS and FTIR analysis were used to confirm the deposition of apatite on the surface of nanofibers. The results of this study suggest that this apatite coated nanofibrous scaffolds could be a suitable biomaterial for bone tissue engineering.
    Matched MeSH terms: Calcium Phosphates/chemistry
  9. 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*
  10. Chow YH, Yap YJ, Tan CP, Anuar MS, Tejo BA, Show PL, et al.
    J Biosci Bioeng, 2015 Jul;120(1):85-90.
    PMID: 25553974 DOI: 10.1016/j.jbiosc.2014.11.021
    In this paper, a linear relationship is proposed relating the natural logarithm of partition coefficient, ln K for protein partitioning in poly (ethylene glycol) (PEG)-phosphate aqueous two-phase system (ATPS) to the square of tie-line length (TLL(2)). This relationship provides good fits (r(2) > 0.98) to the partition of bovine serum albumin (BSA) in PEG (1450 g/mol, 2000 g/mol, 3350 g/mol, and 4000 g/mol)-phosphate ATPS with TLL of 25.0-50.0% (w/w) at pH 7.0. Results also showed that the plot of ln K against pH for BSA partitioning in the ATPS containing 33.0% (w/w) PEG1450 and 8.0% (w/w) phosphate with varied working pH between 6.0 and 9.0 exhibited a linear relationship which is in good agreement (r(2) = 0.94) with the proposed relationship, ln K = α' pH + β'. These results suggested that both the relationships proposed could be applied to correlate and elucidate the partition behavior of biomolecules in the polymer-salt ATPS. The influence of other system parameters on the partition behavior of BSA was also investigated. An optimum BSA yield of 90.80% in the top phase and K of 2.40 was achieved in an ATPS constituted with 33.0% (w/w) PEG 1450 and 8.0% (w/w) phosphate in the presence of 8.5% (w/w) sodium chloride (NaCl) at pH 9.0 for 0.3% (w/w) BSA load.
    Matched MeSH terms: Phosphates/chemistry
  11. Haque ST, Islam RA, Gan SH, Chowdhury EH
    Int J Mol Sci, 2020 Sep 14;21(18).
    PMID: 32937817 DOI: 10.3390/ijms21186721
    Background: The limitations of conventional treatment modalities in cancer, especially in breast cancer, facilitated the necessity for developing a safer drug delivery system (DDS). Inorganic nano-carriers based on calcium phosphates such as hydroxyapatite (HA) and carbonate apatite (CA) have gained attention due to their biocompatibility, reduced toxicity, and improved therapeutic efficacy. Methods: In this study, the potential of goose bone ash (GBA), a natural derivative of HA or CA, was exploited as a pH-responsive carrier to successfully deliver doxorubicin (DOX), an anthracycline drug into breast cancer cells (e.g., MCF-7 and MDA-MB-231 cells). GBA in either pristine form or in suspension was characterized in terms of size, morphology, functional groups, cellular internalization, cytotoxicity, pH-responsive drug (DOX) release, and protein corona analysis. Results: The pH-responsive drug release study demonstrated the prompt release of DOX from GBA through its disintegration in acidic pH (5.5-6.5), which mimics the pH of the endosomal and lysosomal compartments as well as the stability of GBA in physiological pH (pH 7.5). The result of DOX binding with GBA indicated an increment in binding affinity with increasing concentrations of DOX. Cell viability and cytotoxicity analysis showed no innate toxicity of GBA particles. Both qualitative and quantitative cellular uptake analysis in both cell lines displayed an enhanced cellular internalization of DOX-loaded GBA compared to free DOX molecules. The protein corona spontaneously formed on the surface of GBA particles exhibited its affinity toward transport proteins, structural proteins, and a few other selective proteins. The adsorption of transport proteins could extend the circulation half-life in biological environment and increase the accumulation of the drug-loaded NPs through the enhanced permeability and retention (EPR) effect at the tumor site. Conclusion: These findings highlight the potential of GBA as a DDS to successfully deliver therapeutics into breast cancer cells.
    Matched MeSH terms: Calcium Phosphates/chemistry
  12. Kandandapani S, Tan CY, Shuib AS, Tayyab S
    Protein Pept Lett, 2016;23(6):537-43.
    PMID: 26936029
    The influence of buffer composition on the conformational stability of native and calciumdepleted Bacillus licheniformis α-amylase (BLA) was investigated against guanidine hydrochloride (GdnHCl) denaturation using circular dichroism, fluorescence and UV-difference spectroscopy. Differential effect of buffer composition on GdnHCl denaturation of BLA was evident from the magnitude of these spectral signals, which followed the order: sodium phosphate > Tris-HCl > HEPES > MOPS. These effects became more pronounced with calcium-depleted BLA. Sephacryl S-200 gel chromatographic results showed significant BLA aggregation in the presence of 6 M GdnHCl.
    Matched MeSH terms: Phosphates/chemistry*
  13. Lee KK, Kassim AM, Lee HK
    Water Sci Technol, 2004;50(5):73-7.
    PMID: 15497832
    White-rot fungi, namely Coriolus versicolor and Schizophyllum commune, were studied for the biodecolorization of textile dyeing effluent in shaker-flask experiments. The results showed that C. versicolor was able to achieve 68% color removal after 5 days of treatment while that of S. commune was 88% in 9 days. Both fungi achieved the above results in non-sterile condition with diammonium hydrogen phosphate as the nutrient supplement. On the other hand, the best COD removal of 80% was obtained with C. versicolor in 9 days in sterile effluent with yeast extract as nutrient supplement, while S. commune was able to remove 85% COD within 8 days in non-sterile textile effluent supplemented with diammonium hydrogen phosphate.
    Matched MeSH terms: Phosphates/chemistry
  14. Liau KF, Shoji T, Ong YH, Chua AS, Yeoh HK, Ho PY
    Bioprocess Biosyst Eng, 2015 Apr;38(4):729-37.
    PMID: 25381606 DOI: 10.1007/s00449-014-1313-3
    A recently reported stable and efficient EBPR system at high temperatures around 30 °C has led to characterization of kinetic and stoichiometric parameters of the Activated Sludge Model no. 2d (ASM2d). Firstly, suitable model parameters were selected by identifiability analysis. Next, the model was calibrated and validated. ASM2d was found to represent the processes well at 28 and 32 °C except in polyhyroxyalkanoate (PHA) accumulation of the latter. The values of the kinetic parameters for PHA storage (q PHA), polyphosphate storage (q PP) and growth (μ PAO) of polyphosphate-accumulating organisms (PAOs) at 28 and 32 °C were found to be much higher than those reported by previous studies. Besides, the value of the stoichiometric parameter for the requirement of polyphosphate for PHA storage (Y PO4) was found to decrease as temperature rose from 28 to 32 °C. Values of two other stoichiometric parameters, i.e. the growth yield of heterotrophic organisms (Y H) and PAOs (Y PAO), were high at both temperatures. These calibrated parameters imply that the extremely active PAOs of the study were able to store PHA, store polyphosphate and even utilize PHA for cell growth. Besides, the parameters do not follow the Arrhenius correlation due to the previously reported unique microbial clade at 28 and 32 °C, which actively performs EBPR at high temperatures.
    Matched MeSH terms: Phosphates/chemistry; Polyphosphates/chemistry
  15. Lin YK, Show PL, Yap YJ, Ariff AB, Mohammad Annuar MS, Lai OM, et al.
    J Biosci Bioeng, 2016 Jun;121(6):692-696.
    PMID: 26702953 DOI: 10.1016/j.jbiosc.2015.11.001
    Aqueous two-phase system (ATPS) extractive bioconversion provides a technique which integrates bioconversion and purification into a single step process. Extractive bioconversion of gamma-cyclodextrin (γ-CD) from soluble starch with cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) enzyme derived from Bacillus cereus was evaluated using polyethylene glycol (PEG)/potassium phosphate based on ATPS. The optimum condition was attained in the ATPS constituted of 30.0% (w/w) PEG 3000 g/mol and 7.0% (w/w) potassium phosphate. A γ-CD concentration of 1.60 mg/mL with a 19% concentration ratio was recovered after 1 h bioconversion process. The γ-CD was mainly partitioned to the top phase (YT=81.88%), with CGTase partitioning in the salt-rich bottom phase (KCGTase=0.51). Repetitive batch processes of extractive bioconversion were successfully recycled three times, indicating that this is an environmental friendly and a cost saving technique for γ-CD production and purification.
    Matched MeSH terms: Phosphates/chemistry*
  16. Low KL, Tan SH, Zein SH, Roether JA, Mouriño V, Boccaccini AR
    J Biomed Mater Res B Appl Biomater, 2010 Jul;94(1):273-86.
    PMID: 20336722 DOI: 10.1002/jbm.b.31619
    A major weakness of current orthopedic implant materials, for instance sintered hydroxyapatite (HA), is that they exist as a hardened form, requiring the surgeon to fit the surgical site around an implant to the desired shape. This can cause an increase in bone loss, trauma to the surrounding tissue, and longer surgical time. A convenient alternative to harden bone filling materials are injectable bone substitutes (IBS). In this article, recent progress in the development and application of calcium phosphate (CP)-based composites use as IBS is reviewed. CP materials have been used widely for bone replacement because of their similarity to the mineral component of bone. The main limitation of bulk CP materials is their brittle nature and poor mechanical properties. There is significant effort to reinforce or improve the mechanical properties and injectability of calcium phosphate cement (CPC) and this review resumes different alternatives presented in this specialized literature.
    Matched MeSH terms: Calcium Phosphates/chemistry*
  17. 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*
  18. Md Ramli SH, Wong TW, Naharudin I, Bose A
    Carbohydr Polym, 2016 Nov 05;152:370-381.
    PMID: 27516284 DOI: 10.1016/j.carbpol.2016.07.021
    Conventional alginate pellets underwent rapid drug dissolution and failed to exert colon targeting unless subjected to complex coating. This study designed coatless delayed-release oral colon-specific alginate pellets for ulcerative colitis treatment. Alginate pellets, formulated with water-insoluble ethylcellulose and various calcium salts, were prepared using solvent-free melt pelletization technique which prevented reaction between processing materials during agglomeration and allowed reaction to initiate only in dissolution. Combination of acid-soluble calcium carbonate and highly water-soluble calcium acetate did not impart colon-specific characteristics to pellets due to pore formation in fragmented matrices. Combination of moderately water-soluble calcium phosphate and calcium acetate delayed drug release due to rapid alginate crosslinking by soluble calcium from acetate salt followed by sustaining alginate crosslinking by calcium phosphate. The use of 1:3 ethylcellulose-to-alginate enhanced the sustained drug release attribute. The ethylcellulose was able to maintain the pellet integrity without calcium acetate. Using hydrophobic prednisolone as therapeutic, hydrophilic alginate pellets formulated with hydrophobic ethylcellulose and moderately polar calcium phosphate exhibited colon-specific in vitro drug release and in vivo anti-inflammatory action. Coatless oral colon-specific alginate pellets can be designed through optimal formulation with melt pelletization as the processing technology.
    Matched MeSH terms: Calcium Phosphates/chemistry
  19. Mohamed Saat A, Johan MR
    ScientificWorldJournal, 2014;2014:439839.
    PMID: 25506069 DOI: 10.1155/2014/439839
    Partially phosphorylated polyvinyl alcohol (PPVA) with aluminum phosphate (ALPO4) composites was synthesized by solution casting technique to produce (PPVA)(100-y) - (ALPO4)(y) (y = 0, 1, and 2). The surface structure and thermal properties of the films were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The results showed that the films have higher thermal stability with strong bonding between PPVA and ALPO4.
    Matched MeSH terms: Phosphates/chemistry*
  20. Mohammadi H, Sepantafar M
    Iran Biomed J, 2016 Sep;20(4):189-200.
    PMID: 26979401
    Titanium and its alloy are known as important load-bearing biomaterials. The major drawbacks of these metals are fibrous formation and low corrosion rate after implantation. The surface modification of biomedical implants through various methods such as plasma spray improves their osseointegration and clinical lifetime. Different materials have been already used as coatings on biomedical implant, including calcium phosphates and bioglass. However, these materials have been reported to have limited clinical success. The excellent bioactivity of calcium silicate (Ca-Si) has been also regarded as coating material. However, their high degradation rate and low mechanical strength limit their further coating application. Trace element modification of (Ca-Si) bioceramics is a promising method, which improves their mechanical strength and chemical stability. In this review, the potential of trace element-modified silicate coatings on better bone formation of titanium implant is investigated.
    Matched MeSH terms: Calcium Phosphates/chemistry
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