Displaying publications 61 - 80 of 129 in total

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  1. Differential osteogenic activity of osteoprogenitor cells on HA and TCP/HA scaffold of tissue engineered bone
    Ng AM, Tan KK, Phang MY, Aziyati O, Tan GH, Isa MR, et al.
    J Biomed Mater Res A, 2008 May;85(2):301-12.
    PMID: 17688285
    Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma-derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering.
    Matched MeSH terms: Durapatite*
  2. Cell death induced by hydroxyapatite on L929 fibroblast cells
    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: Durapatite/toxicity*
  3. Comparative study between dense and porous hydroxyapatite using light and scanning electron microscopy
    Pohchi A, Suzina AH, Samsudin AR, Al-Salihi KA
    Med J Malaysia, 2004 May;59 Suppl B:151-2.
    PMID: 15468863
    This in vivo study revealed that porous hydroxyapatite (PHA) and dense hydroxyapatite (DHA) are good implant materials that can accelerate bone healing and resorbed in acceptable time. But there were differences in the mechanism of the resorption of DHA and PHA due to variability in the physical properties and osteogenicity.
    Matched MeSH terms: Durapatite/analysis*
  4. Mechanical and physical behavior of newly developed functionally graded materials and composites of stainless steel 316L with calcium silicate and hydroxyapatite
    Ataollahi Oshkour A, Pramanik S, Mehrali M, Yau YH, Tarlochan F, Abu Osman NA
    J Mech Behav Biomed Mater, 2015 Sep;49:321-31.
    PMID: 26072197 DOI: 10.1016/j.jmbbm.2015.05.020
    This study aimed to investigate the structural, physical and mechanical behavior of composites and functionally graded materials (FGMs) made of stainless steel (SS-316L)/hydroxyapatite (HA) and SS-316L/calcium silicate (CS) employing powder metallurgical solid state sintering. The structural analysis using X-ray diffraction showed that the sintering at high temperature led to the reaction between compounds of the SS-316L and HA, while SS-316L and CS remained intact during the sintering process in composites of SS-316L/CS. A dimensional expansion was found in the composites made of 40 and 50 wt% HA. The minimum shrinkage was emerged in 50 wt% CS composite, while the maximum shrinkage was revealed in samples with pure SS-316L, HA and CS. Compressive mechanical properties of SS-316L/HA decreased sharply with increasing of HA content up to 20 wt% and gradually with CS content up to 50 wt% for SS-316L/CS composites. The mechanical properties of the FGM of SS-316L/HA dropped with increase in temperature, while it was improved for the FGM of SS-316L/CS with temperature enhancement. It has been found that the FGMs emerged a better compressive mechanical properties compared to both the composite systems. Therefore, the SS-316L/CS composites and their FGMs have superior compressive mechanical properties to the SS-316L/HA composites and their FGMs and also the newly developed FGMs of SS-316L/CS with improved mechanical and enhanced gradation in physical and structural properties can potentially be utilized in the components with load-bearing application.
    Matched MeSH terms: Durapatite/chemistry*
  5. Structure-property relationships of iron-hydroxyapatite ceramic matrix nanocomposite fabricated using mechanosynthesis method
    Nordin JA, Prajitno DH, Saidin S, Nur H, Hermawan H
    Mater Sci Eng C Mater Biol Appl, 2015 Jun;51:294-9.
    PMID: 25842138 DOI: 10.1016/j.msec.2015.03.019
    Hydroxyapatite (HAp) is an attractive bioceramics due to its similar composition to bone mineral and its ability to promote bone-implant interaction. However, its low strength has limited its application as load bearing implants. This paper presented a work focusing on the improvement of HAp mechanical property by synthesizing iron (Fe)-reinforced bovine HAp nanocomposite powders via mechanosynthesis method. The synthesis process was performed using high energy milling at varied milling time (3, 6, 9, and 12h). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Its mechanical properties were investigated by micro-Vicker's hardness and compression tests. Results showed that milling time directly influenced the characteristics of the nanocomposite powders. Amorphous BHAp was formed after 9 and 12h milling in the presence of HPO4(2-) ions. Continuous milling has improved the crystallinity of Fe without changing the HAp lattice structure. The nanocomposite powders were found in spherical shape, agglomerated and dense after longer milling time. The hardness and Young's modulus of the nanocomposites were also increased at 69% and 66%, respectively, as the milling time was prolonged from 3 to 12h. Therefore, the improvement of the mechanical properties of nanocomposite was attributed to high Fe crystallinity and homogenous, dense structure produced by mechanosynthesis.
    Matched MeSH terms: Durapatite/chemistry*
  6. The development of a tool to predict temperature-exposure of incinerated teeth using colourimetric and hydroxyapatite crystal size data
    Rahmat RA, Humphries MA, Austin JJ, Linacre AMT, Self P
    Int J Legal Med, 2021 Sep;135(5):2045-2053.
    PMID: 33655354 DOI: 10.1007/s00414-021-02538-7
    This study presents a novel tool to predict temperature-exposure of incinerated pig teeth as a proxy for understanding impacts of fire on human teeth. Previous studies on the estimation of temperature-exposure of skeletal elements have been limited to that of heat-exposed bone. This predictive tool was developed using a multinomial regression model of colourimetric and hydroxyapatite crystal size variables using data obtained from unheated pig teeth and teeth incinerated at 300 °C, 600 °C, 800 °C and 1000 °C. An additional variable based on the observed appearance of the tooth was included in the tool. This enables the tooth to be classified as definitely burnt (600 °C-1000 °C) or uncertain (27 °C/300 °C). As a result, the model predicting the temperature-exposure of the incinerated teeth had an accuracy of 95%. This tool is a holistic, robust and reliable approach to estimate temperature of heat-exposed pig teeth, with high accuracy, and may act as a valuable proxy to estimate heat exposure for human teeth in forensic casework.
    Matched MeSH terms: Durapatite/analysis*
  7. Bioactivity and mechanical stability of Ti-6Al-4V implants superplastically embedded with hydroxyapatite in rats
    Mohd Khalid H, Jauhari I, Mohamad Wali HA, Abdulrazzaq Mahmod S
    Biomed Mater, 2017 01 25;12(1):015019.
    PMID: 28120816 DOI: 10.1088/1748-605X/aa4f8b
    In this in vivo study, Sprague Dawley (SD) rats were used to investigate the bioactivity as well as the microstructural and mechanical properties of Ti-6Al-4V samples embedded with hydroxyapatite (HA) using two different coating methods-superplastic embedment (SPE) and superplastic deformation (SPD). The HA layer thickness for the SPE and SPD samples increased from 249.1  ±  0.6 nm to 874.8  ±  13.7 nm, and from 206.1  ±  5.8 nm to 1162.7  ±  7.9 nm respectively, after 12 weeks of implantation. The SPD sample exhibited much faster growth of newly formed HA compared to SPE. The growth of the newly formed HA was strongly dependent on the degree of HA crystallinity in the initial HA layer. After 12 weeks of implantation, the surface hardness value of the SPE and SPD samples decreased from 661  ±  0.4 HV to 586  ±  1.3 HV and from 585  ±  6.6 HV to 425  ±  86.9 HV respectively. The decrease in surface hardness values was due to the newly formed HA layer that was more porous than the initial HA layer. However, the values were still higher than the substrate surface hardness of 321  ±  28.8 HV. Wear test results suggest that the original HA layers for both samples were still strongly intact, and to a certain extent the newly grown HA layers also were strongly bound with the original HA layers. This study confirms the bioactivity and mechanical stability of the HA layer on both samples in vivo.
    Matched MeSH terms: Durapatite/chemistry*
  8. Influence of citric acid on the physical and biomineralization ability of freeze/thaw poly(vinyl alcohol) hydrogel
    Wahid MNA, Abd Razak SI, Abdul Kadir MR, Hassan R, Nayan NHM, Mat Amin KA
    J Biomater Appl, 2018 07;33(1):94-102.
    PMID: 29716417 DOI: 10.1177/0885328218771195
    This work reports the modification of freeze/thaw poly(vinyl alcohol) hydrogel using citric acid as the bioactive molecule for hydroxyapatite formation in simulated body fluid. Inclusion of 1.3 mM citric acid into the poly(vinyl alcohol) hydrogel showed that the mechanical strength, crystalline phase, functional groups and swelling ability were still intact. Adding citric acid at higher concentrations (1.8 and 2.3 mM), however, resulted in physically poor hydrogels. Presence of 1.3 mM of citric acid showed the growth of porous hydroxyapatite crystals on the poly(vinyl alcohol) surface just after one day of immersion in simulated body fluid. Meanwhile, a fully covered apatite layer on the poly(vinyl alcohol) surface plus the evidence of apatite forming within the hydrogel were observed after soaking for seven days. Gel strength of the soaked poly(vinyl alcohol)/citric acid-1.3 mM hydrogel revealed that the load resistance was enhanced compared to that of the neat poly(vinyl alcohol) hydrogel. This facile method of inducing rapid growth of hydroxyapatite on the hydrogel surface as well as within the hydrogel network can be useful for guided bone regenerative materials.
    Matched MeSH terms: Durapatite/chemistry*
  9. In vitro biocompatibility of hydroxyapatite-added GIC: An SEM study using human periodontal ligament fibroblasts
    Thomas B, Gupta K
    J Esthet Restor Dent, 2017 Nov 12;29(6):435-441.
    PMID: 28703476 DOI: 10.1111/jerd.12317
    OBJECTIVE: Nano-hydroxyapatite-added GIC has been developed to improve the physical properties of conventional GIC. However, biological response of periodontal cells to this potentially useful cervical restorative material has been unexplored. The aim of this study was to investigate the in vitro response of human periodontal ligament fibroblasts to hydroxyapatite-added GIC.

    MATERIALS AND METHODS: Three categories of materials, namely, test group 1 (cGIC or type IX GIC), test group 2 (HA-GIC or hydroxyapatite-added GIC), and positive control (glass cover slips) were incubated with human periodontal ligament fibroblasts. The samples were viewed under scanning electron microscope to study the morphological characteristics of fibroblasts. Additionally, elemental analysis was performed to differentiate between the two test groups based on surface chemical composition.

    RESULTS: Test group 1 (cGIC) exhibited cells with curled up morphology, indicative of poor attachment to the substrate. Test group 2 (Ha-GIC) exhibited cells with flattened morphology and numerous cellular extensions such as lamellipodia and blebs, indicative of good attachment to the substrate. The test group 2 (Ha-GIC) demonstrated higher surface elemental percentages of calcium and phosphorus.

    CONCLUSION: Within the limitations of this study, it may be concluded that hydroxyapatite-added GIC is more biocompatible than conventional GIC (type IX), probably attributed to high elemental percentages of calcium and phosphorus.

    CLINICAL SIGNIFICANCE: The search for an ideal cervical restorative dental material has been ever elusive. Hydroxyapatite-added GIC is a simple and economical dental material to fabricate from basic conventional GIC. The results from this study strengthen its candidature for cervical and root surface restorations which may later require soft tissue augmentation. The possibility of connective tissue adhesion to this material is an exciting prospect in the field of periorestorative dentistry.

    Matched MeSH terms: Durapatite/pharmacology*
  10. Fabrication and performance evaluation of polymeric membrane using blood compatible hydroxyapatite for artificial kidney application
    Zaman SU, Saif-Ur-Rehman, Zaman MKU, Rafiq S, Arshad A, Khurram MS, et al.
    Artif Organs, 2021 Nov;45(11):1377-1390.
    PMID: 34152645 DOI: 10.1111/aor.14020
    In the current study, a phase inversion scheme was employed to fabricate hydroxyapatite (HA)/polysulfone (PSF)-based asymmetric membranes using a film applicator with water as a solvent and nonsolvent exchanging medium. Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) spectroscopic studies were conducted to confirm the bonding chemistry and purity of filler. The inherent thick nature of PSF generated sponge-like shape while the instantaneous demixing process produced finger-like pore networks in HA/PSF-based asymmetric membranes as exhibited by scanning electron microscope (SEM) micrographs. The FTIR spectra confirmed noncovalent weak attractions toward the polymer surface. The leaching ratio was evaluated to observe the dispersion behavior of HA filler in membrane composition. Hydrophilicity, pore profile, pure water permeation (PWP) flux, and molecular weight cutoff (MWCO) values of all formulated membranes were also calculated. Antifouling results revealed that HA modified PSF membranes exhibited 43% less adhesion of bovine serum albumin (BSA) together with >86% recovery of flux. Membrane composition showed 74% total resistance, out of which 60% was reversible resistance. Biocompatibility evaluation revealed that the modified membranes exhibited prothrombin time (PT), and thrombin time (TT) comparable with typical blood plasma, whereas proliferation of living cells over membrane surface proved its nontoxic behavior toward biomedical application. The urea and creatinine showed effective adsorption aptitude toward HA loaded PSF membranes.
    Matched MeSH terms: Durapatite/chemistry*
  11. Bone tissue engineering potentials of 3D printed magnesium-hydroxyapatite in polylactic acid composite scaffolds
    Anita Lett J, Sagadevan S, Léonard E, Fatimah I, Motalib Hossain MA, Mohammad F, et al.
    Artif Organs, 2021 Dec;45(12):1501-1512.
    PMID: 34309044 DOI: 10.1111/aor.14045
    The primary role of bone tissue engineering is to reconcile the damaged bones and facilitate the speedy recovery of the injured bones. However, some of the investigated metallic implants suffer from stress-shielding, palpability, biocompatibility, etc. Consequently, the biodegradable scaffolds fabricated from polymers have gathered much attention from researchers and thus helped the tissue engineering sector by providing many alternative materials whose functionality is similar to that of natural bones. Herein, we present the fabrication and testing of a novel composite, magnesium (Mg)-doped hydroxyapatite (HAp) glazed onto polylactic acid (PLA) scaffolds where polyvinyl alcohol (PVA) used as a binder. For the composite formation, Creality Ender-3 pro High Precision 3D Printer with Shape tool 3D Technology on an FSD machine operated by Catia design software was employed. The composite has been characterized for the crystallinity (XRD), surface functionality (FTIR), morphology (FESEM), biocompatibility (hemolytic and protein absorption), and mechanical properties (stress-strain and maximum compressive strength). The powder XRD analysis confirmed the semicrystalline nature and intact structure of HAp even after doping with Mg, while FTIR studies for the successful formation of Mg-HAp/PVA@PLA composite. The FESEM provided analysis indicated for the 3D porous architecture and well-defined morphology to efficiently transport the nutrients, and the biocompatibility studies are supporting that the composite for blood compatible with the surface being suitable enough for the protein absorption. Finally, the composite's antibacterial activity (against Staphylococcus aureus and Escherichia coli) and the test of mechanical properties supported for the enhanced inhibition of active growth of microorganisms and maximum compressive strength, respectively. Based on the research outcomes of biocompatibility, antibacterial activity, and mechanical resistance, the fabricated Mg-HAp/PVA@PLA composite suits well as a promising biomaterial platform for orthopedic applications by functioning towards the open reduction internal fixation of bone fractures and internal repairs.
    Matched MeSH terms: Durapatite/chemistry
  12. The synthesis, characterization and in vivo study of mineral substituted hydroxyapatite for prospective bone tissue rejuvenation applications
    Govindaraj D, Rajan M, Munusamy MA, Alarfaj AA, Sadasivuni KK, Kumar SS
    Nanomedicine, 2017 Nov;13(8):2661-2669.
    PMID: 28800874 DOI: 10.1016/j.nano.2017.07.017
    Minerals substituted apatite (M-HA) nanoparticles were prepared by the precipitation of minerals and phosphate reactants in choline chloride-Thiourea (ChCl-TU) deep eutectic solvent (DESs) as a facile and green way approach. After preparation of nanoparticles (F-M-HA (F=Fresh solvent)), the DESs was recovered productively and reprocess for the preparation of R-M-HA nanoparticles (R=Recycle solvent).The functional groups, phase, surface texture and the elemental composition of the M-HA nanoparticles were evaluated by advance characterization methods. The physicochemical results of the current work authoritative the successful uses of the novel (ChCl-TU) DESs as eco-friendly recuperate and give the medium for the preparation of M-HA nanoparticles. Moreover, the as-synthesized both M-HA nanoparticles exhibit excellent biocompatibility, consisting of cell co-cultivation and cell adhesion, in vivo according to surgical implantation of Wistar rats.
    Matched MeSH terms: Durapatite/therapeutic use*
  13. Immobilisation of hydroxyapatite-collagen on polydopamine grafted stainless steel 316L: Coating adhesion and in vitro cells evaluation
    Tapsir Z, Jamaludin FH, Pingguan-Murphy B, Saidin S
    J Biomater Appl, 2018 02;32(7):987-995.
    PMID: 29187035 DOI: 10.1177/0885328217744081
    The utilisation of hydroxyapatite and collagen as bioactive coating materials could enhance cells attachment, proliferation and osseointegration. However, most methods to form crystal hydroxyapatite coating do not allow the incorporation of polymer/organic compound due to production phase of high sintering temperature. In this study, a polydopamine film was used as an intermediate layer to immobilise hydroxyapatite-collagen without the introduction of high sintering temperature. The surface roughness, coating adhesion, bioactivity and osteoblast attachment on the hydroxyapatite-collagen coating were assessed as these properties remains unknown on the polydopamine grafted film. The coating was developed by grafting stainless steel 316L disks with a polydopamine film. Collagen type I fibres were then immobilised on the grafted film, followed by the biomineralisation of hydroxyapatite. The surface roughness and coating adhesion analyses were later performed by using AFM instrument. An Alamar Blue assay was used to determine the cytotoxicity of the coating, while an alkaline phosphatase activity test was conducted to evaluate the osteogenic differentiation of human fetal osteoblasts on the coating. Finally, the morphology of cells attachment on the coating was visualised under FESEM. The highest RMS roughness and coating adhesion were observed on the hydroxyapatite-collagen coating (hydroxyapatite-coll-dopa). The hydroxyapatite-coll-dopa coating was non-toxic to the osteoblast cells with greater cells proliferation, greater level of alkaline phosphate production and more cells attachment. These results indicate that the immobilisation of hydroxyapatite and collagen using an intermediate polydopamine is identical to enhance coating adhesion, osteoblast cells attachment, proliferation and differentiation, and thus could be implemented as a coating material on orthopaedic and dental implants.
    Matched MeSH terms: Durapatite/chemistry*
  14. Synthesis and characterization of cellulose and hydroxyapatite-carbon electrode composite for trace plumbum ions detection and its validation in blood serum
    Ajab H, Dennis JO, Abdullah MA
    Int J Biol Macromol, 2018 Jul 01;113:376-385.
    PMID: 29486259 DOI: 10.1016/j.ijbiomac.2018.02.133
    A novel synthesis and characterization of cellulose, hydroxyapatite and chemically-modified carbon electrode (Cellulose-HAp-CME) composite was reported for the analysis of trace Pb(II) ions detection and its validation in blood serum. The Field Emission Scanning Electron Microscopy (FESEM) analyses showed that the composite retained the orderly porous structure but with scattered particle size agglomeration. The Fourier Transform Infrared Spectroscopy (FTIR) spectra suggested the presence of functional groups associated with the bending and stretching of carbon bonds and intermolecular H-bonding. X-ray Diffraction (XRD) analyses further elucidated that the crystallite size could have influenced the properties of the electrode. Based on Thermo-gravimetric Analysis (TGA/DTG), the composites showed thermal stability with more than 60% residual content at 700°C. The sensor was successfully developed for trace Pb(II) ions detection in complex medium such as blood serum, in the physiologically relevant range of 10-60ppb, with resulting Limit of Detection (LOD) of 0.11±0.36ppb and Limit of Quantification (LOQ) of 0.36±0.36ppb. The newly fabricated electrode could be advantageous as a sensing platform with favourable electrochemical characteristics for robust, in situ and rapid environmental and clinical analyses of heavy metal ions.
    Matched MeSH terms: Durapatite/chemistry*
  15. Biofilm formation of periodontal pathogens on hydroxyapatite surfaces: Implications for periodontium damage
    Jaffar N, Miyazaki T, Maeda T
    J Biomed Mater Res A, 2016 11;104(11):2873-80.
    PMID: 27390886 DOI: 10.1002/jbm.a.35827
    Biofilm formation of periodontal pathogens on teeth surfaces promotes the progression of periodontal disease. Hence, understanding the mechanisms of bacterial attachment to the dental surfaces may inform strategies for the maintenance of oral health. Although hydroxyapatite (HA) is a major calcium phosphate component of teeth, effect of biofilm formation on HA surfaces remains poorly characterized. In this study, biofilm-forming abilities by the periodontal pathogens Aggregatibacter actinomycetemcomitans Y4 and Porphyromonas gingivalis 381 were investigated on dense and porous HAs that represent enamel and dentin surfaces, respectively. These experiments showed greater biofilm formation on porous HA, but differing attachment profiles and effects of the two pathogens. Specifically, while the detachment of A. actinomycetemcomitans Y4 biofilm was observed, P. gingivalis 381 biofilm increased with time. Moreover, observations of HA morphology following formation of A. actinomycetemcomitans Y4 biofilm revealed gaps between particles, whereas no significant changes were observed in the presence of P. gingivalis 381. Finally, comparisons of calcium leakage showed only slight differences between bacterial species and HA types and may be masked by bacterial calcium uptake. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2873-2880, 2016.
    Matched MeSH terms: Durapatite/chemistry*
  16. Fulltext Effects of the Sintering Process on Nacre-Derived Hydroxyapatite Scaffolds for Bone Engineering
    Megat Abdul Wahab R, Abdullah N, Zainal Ariffin SH, Che Abdullah CA, Yazid F
    Molecules, 2020 Jul 08;25(14).
    PMID: 32650572 DOI: 10.3390/molecules25143129
    A hydroxyapatite scaffold is a suitable biomaterial for bone tissue engineering due to its chemical component which mimics native bone. Electronic states which present on the surface of hydroxyapatite have the potential to be used to promote the adsorption or transduction of biomolecules such as protein or DNA. This study aimed to compare the morphology and bioactivity of sinter and nonsinter marine-based hydroxyapatite scaffolds. Field emission scanning electron microscopy (FESEM) and micro-computed tomography (microCT) were used to characterize the morphology of both scaffolds. Scaffolds were co-cultured with 5 × 104/cm2 of MC3T3-E1 preosteoblast cells for 7, 14, and 21 days. FESEM was used to observe the cell morphology, and MTT and alkaline phosphatase (ALP) assays were conducted to determine the cell viability and differentiation capacity of cells on both scaffolds. Real-time polymerase chain reaction (rtPCR) was used to identify the expression of osteoblast markers. The sinter scaffold had a porous microstructure with the presence of interconnected pores as compared with the nonsinter scaffold. This sinter scaffold also significantly supported viability and differentiation of the MC3T3-E1 preosteoblast cells (p < 0.05). The marked expression of Col1α1 and osteocalcin (OCN) osteoblast markers were also observed after 14 days of incubation (p < 0.05). The sinter scaffold supported attachment, viability, and differentiation of preosteoblast cells. Hence, sinter hydroxyapatite scaffold from nacreous layer is a promising biomaterial for bone tissue engineering.
    Matched MeSH terms: Durapatite/chemistry*
  17. Role of nitric oxide in hydroxyapatite-induced phagocytosis by murine macrophage cell line (RAW264.7)
    Gopinath VK, Musa M, Samsudin AR, Lalitha P, Sosroseno W
    Arch Oral Biol, 2006 Apr;51(4):339-44.
    PMID: 16214104
    The aim of this study was to determine the role of nitric oxide (NO) in hydroxyapatite (HA)-induced phagocytosis by a murine macrophage cell line (RAW264.7). The cells were incubated with HA particles at various incubation time and phagocytosis was assessed using phagocytic index (PI). NO production from the culture supernatants was determined by the Griess reagent. The inducible nitric oxide synthase (iNOS) expression was determined by Western blot. The particles were also incubated with cells pretreated with various concentrations of L-N(6)-(1-iminoethyl) lysine hydrochloride (L-NIL) or L-arginine. Latex beads were used as a control. Our results showed that macrophage phagocytosis induced by HA was higher than that induced by the beads. However, NO production by HA-stimulated cells was lower than that by bead-stimulated cells. iNOS expression in both bead- and HA-stimulated cells was observed expressed at 7, 15, 30, and 60 min. l-Arginine enhanced but l-NIL inhibited both phagocytosis and NO production by HA-stimulated cells. The results of the present study suggest that nitric oxide may play a crucial role in HA-induced phagocytosis by RAW264.7 cells.
    Matched MeSH terms: Durapatite/immunology*; Durapatite/pharmacology
  18. Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study
    Chadda H, Naveen SV, Mohan S, Satapathy BK, Ray AR, Kamarul T
    J Prosthet Dent, 2016 Jul;116(1):129-35.
    PMID: 26873771 DOI: 10.1016/j.prosdent.2015.12.013
    STATEMENT OF PROBLEM: Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail.

    PURPOSE: The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination.

    MATERIAL AND METHODS: Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software.

    RESULTS: Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis.

    CONCLUSIONS: The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials.

    Matched MeSH terms: Durapatite/adverse effects*; Durapatite/therapeutic use
  19. Role of protein kinase C in hydroxyapatite- induced phagocytosis by a murine macrophage cell line (RAW264.7)
    Gopinath VK, Musa M, Samsudin AR, Sosroseno W
    Immunopharmacol Immunotoxicol, 2006;28(3):485-9.
    PMID: 16997796
    The role of protein kinase C (PKC) in hydroxyapatite (HA)-induced phagocytosis by RAW 264.7 cells was investigated. The cells were incubated with HA particles at various incubation time and the levels of PKC activity were determined from the cell lysate. To determine the role of PKC, particles were incubated with the cells pretreated with the various concentrations of bisindolylmaleimide, a PKC inhibitor, and phagocytosis was then assessed at 60 min. Latex beads were used as a control. Our results showed that following incubation with HA particles, the levels of PKC activity in RAW264.7 cells was highest at 7 min and then decreased to reach the baseline levels of the controls at 30 min. Pretreatment of the cells with bisindolylmaleimide significantly reduced phagocytosis of HA particles in a dose-dependent pattern. The results of our present study suggest therefore that ingestion of HA by RAW264.7 cells may depend on PKC activity that may act in the early stages of phagocytosis.
    Matched MeSH terms: Durapatite/pharmacology*; Durapatite/chemistry
  20. Fulltext Synthesis of silver nanoparticle-decorated hydroxyapatite nanocomposite with combined bioactivity and antibacterial properties
    Bee SL, Bustami Y, Ul-Hamid A, Lim K, Abdul Hamid ZA
    J Mater Sci Mater Med, 2021 Aug 23;32(9):106.
    PMID: 34426879 DOI: 10.1007/s10856-021-06590-y
    Combination of bioactive material such as hydroxyapatite (HAp) with antibacterial agents would have great potential to be used as bone implant materials to avert possible bacterial infection that can lead to implant-associated diseases. The present study aimed to develop an antibacterial silver nanoparticle-decorated hydroxyapatite (HAp/AgNPs) nanocomposite using chemical reduction and thermal calcination approaches. In this work, natural HAp that was extracted from chicken bone wastes is used as support matrix for the deposition of silver nanoparticles (AgNPs) to produce HAp/AgNPs nanocomposite. XRD, FESEM-EDX, HRTEM, and XPS analyses confirmed that spherical AgNPs were successfully synthesized and deposited on the surface of HAp particles, and the amount of AgNPs adhered on the HAp surface increased with increasing AgNO3 concentration used. The synthesized HAp/AgNPs nanocomposites demonstrated strong antibacterial activity against Staphylococcus aureus bacteria, where the antibacterial efficiency is relied on the amount and size of deposited AgNPs. In addition, the in vitro bioactivity examination in Hank's balanced salt solution showed that more apatite were grown on the surface of HAp/AgNPs nanocomposite when AgNO3 concentration used >1 wt.%. Such nanocomposite with enhanced bioactivity and antibacterial properties emerged as a promising biomaterial to be applied for dentistry and orthopedic implantology.
    Matched MeSH terms: Durapatite/pharmacology; Durapatite/chemistry
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