Displaying publications 161 - 180 of 330 in total

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  1. In vitro cytotoxicology model of oligo-chitosan and n, o-carboxymethyl chitosan using primary normal human epidermal keratinocyte cultures
    Lim CK, Halim AS, Lau HY, Ujang Z, Hazri A
    J Appl Biomater Biomech, 2007 May-Aug;5(2):82-7.
    PMID: 20799177
    Chitosan (beta-1, 4-D-glucosamine) is a deacetylated form of chitin with excellent biological properties in wound management. The natural properties of chitosan have the physical and chemical limitations to be widely used in biomedical fields. The improvement of the physical and chemical properties of chitosan with some additional chemicals will alter its biocompatibility. Therefore, the biological attribute of the modified chitosan must be evaluated. In this study, the cytotoxicity of oligo-chitosan (OC) and N, O- carboxymethyl-chitosan (NO-CMC) derivatives (O-C 1%, O-C 5%, NO-CMC 1% and NO-CMC 5%) was evaluated using primary normal human epidermal keratinocyte (pNHEK) cultures as an in vitro toxicology model at standardized cell passages (fourth passages). 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl tetrazolium bromide (MTT) was used as a cell viability assay. The O-C 1% is one of the most compatible chitosan derivatives because it steadily sustained >70% of viable cells until 72 hr post-treatment. This was followed by O-C 5%, NO-CMC 5% and NO-CMC 1%. Therefore, oligo-chitosan had the ideal properties of a biocompatible material compared to N, O- carboxymethyl-chitosan in this study.
    Matched MeSH terms: Biocompatible Materials
  2. Keloid pathogenesis via Drosophila similar to mothers against decapentaplegic (SMAD) signaling in a primary epithelial-mesenchymal in vitro model treated with biomedical-grade chitosan porous skin regenerating template
    Lim CK, Halim AS, Yaacob NS, Zainol I, Noorsal K
    J Biosci Bioeng, 2013 Apr;115(4):453-8.
    PMID: 23177217 DOI: 10.1016/j.jbiosc.2012.10.010
    The effects of locally produced chitosan (CPSRT-NC-bicarbonate) in the intervention of keloid pathogenesis were investigated in vitro. A human keratinocyte-fibroblast co-culture model was established to investigate the protein levels of human collagen type-I, III and V in a western blotting analysis, the secreted transforming growth factor-β1 (TGF-β1) in an enzyme-linked immunosorbent assay (ELISA) and the mRNA levels of TGF-β1's intracellular signaling molecules (SMAD2, 3, 4 and 7) in a real-time PCR analysis. Keratinocyte-fibroblast co-cultures were maintained in DKSFM:DMEM:F12 (2:2:1) medium. Collagen type-I was found to be the dominant form in primary normal human dermal fibroblast (pNHDF) co-cultures, whereas collagen type-III was more abundant in primary keloid-derived human dermal fibroblast (pKHDF) co-cultures. Collagen type-V was present as a minor component in the skin. TGF-β1, SMAD2 and SMAD4 were expressed more in the pKHDF than the pNHDF co-cultures. Co-cultures with normal keratinocytes suppressed collagen type-III, SMAD2, SMAD4 and TGF-β1 expressions and CPSRT-NC-bicarbonate enhanced this effect. In conclusion, the CPSRT-NC-bicarbonate in association with normal-derived keratinocytes demonstrated an ability to reduce TGF-β1, SMAD2 and SMAD4 expressions in keloid-derived fibroblast cultures, which may be useful in keloid intervention.
    Matched MeSH terms: Biocompatible Materials/pharmacology*
  3. A practical three visit complete denture system
    Ling BC
    Ann R Australas Coll Dent Surg, 2000 Oct;15:66-8.
    PMID: 11709981
    Standard prosthodontic procedures require five visits to construct a set of complete maxillary and mandibular dentures. Various attempts have been made to reduce these procedures to four or three appointments. However, most of these techniques require the use of visible light polymerized resin as the final denture base materials. Visible light-cured resin materials have inferior physical properties and biocompatibility problems as compared with heat cured polymethylmethacrylate. This paper describes a system of complete denture construction which requires three clinical appointments instead of the usual five visits. This system is made possible by using the VLC base/tray material as the preliminary impression material as well as the application of a new biometric wax occlusion rim. It retains the use of polymethylmethacrylate as the denture base material. This system also utilizes all the procedures used in the conventional five appointment system of complete denture construction.
    Matched MeSH terms: Biocompatible Materials/chemistry
  4. Tough Supramolecular Polymer Networks with Extreme Stretchability and Fast Room-Temperature Self-Healing
    Liu J, Tan CSY, Yu Z, Li N, Abell C, Scherman OA
    Adv Mater, 2017 Jun;29(22).
    PMID: 28370560 DOI: 10.1002/adma.201605325
    Recent progress on highly tough and stretchable polymer networks has highlighted the potential of wearable electronic devices and structural biomaterials such as cartilage. For some given applications, a combination of desirable mechanical properties including stiffness, strength, toughness, damping, fatigue resistance, and self-healing ability is required. However, integrating such a rigorous set of requirements imposes substantial complexity and difficulty in the design and fabrication of these polymer networks, and has rarely been realized. Here, we describe the construction of supramolecular polymer networks through an in situ copolymerization of acrylamide and functional monomers, which are dynamically complexed with the host molecule cucurbit[8]uril (CB[8]). High molecular weight, thus sufficient chain entanglement, combined with a small-amount dynamic CB[8]-mediated non-covalent crosslinking (2.5 mol%), yields extremely stretchable and tough supramolecular polymer networks, exhibiting remarkable self-healing capability at room temperature. These supramolecular polymer networks can be stretched more than 100× their original length and are able to lift objects 2000× their weight. The reversible association/dissociation of the host-guest complexes bestows the networks with remarkable energy dissipation capability, but also facile complete self-healing at room temperature. In addition to their outstanding mechanical properties, the networks are ionically conductive and transparent. The CB[8]-based supramolecular networks are synthetically accessible in large scale and exhibit outstanding mechanical properties. They could readily lead to the promising use as wearable and self-healable electronic devices, sensors and structural biomaterials.
    Matched MeSH terms: Biocompatible Materials
  5. Fulltext Current Update of Collagen Nanomaterials-Fabrication, Characterisation and Its Applications: A Review
    Lo S, Fauzi MB
    Pharmaceutics, 2021 Feb 28;13(3).
    PMID: 33670973 DOI: 10.3390/pharmaceutics13030316
    Tissue engineering technology is a promising alternative approach for improvement in health management. Biomaterials play a major role, acting as a provisional bioscaffold for tissue repair and regeneration. Collagen a widely studied natural component largely present in the extracellular matrix (ECM) of the human body. It provides mechanical stability with suitable elasticity and strength to various tissues, including skin, bone, tendon, cornea and others. Even though exogenous collagen is commonly used in bioscaffolds, largely in the medical and pharmaceutical fields, nano collagen is a relatively new material involved in nanotechnology with a plethora of unexplored potential. Nano collagen is a form of collagen reduced to a nanoparticulate size, which has its advantages over the common three-dimensional (3D) collagen design, primarily due to its nano-size contributing to a higher surface area-to-volume ratio, aiding in withstanding large loads with minimal tension. It can be produced through different approaches including the electrospinning technique to produce nano collagen fibres resembling natural ECM. Nano collagen can be applied in various medical fields involving bioscaffold insertion or fillers for wound healing improvement; skin, bone, vascular grafting, nerve tissue and articular cartilage regeneration as well as aiding in drug delivery and incorporation for cosmetic purposes.
    Matched MeSH terms: Biocompatible Materials
  6. Calcium phosphate-based composites as injectable bone substitute materials
    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: Biocompatible Materials/metabolism; Biocompatible Materials/chemistry
  7. Fulltext Sonoproduction of nanobiomaterials - A critical review
    Low SS, Yew M, Lim CN, Chai WS, Low LE, Manickam S, et al.
    Ultrason Sonochem, 2022 Jan;82:105887.
    PMID: 34954629 DOI: 10.1016/j.ultsonch.2021.105887
    Ultrasound (US) demonstrates remarkable potential in synthesising nanomaterials, particularly nanobiomaterials targeted towards biomedical applications. This review briefly introduces existing top-down and bottom-up approaches for nanomaterials synthesis and their corresponding synthesis mechanisms, followed by the expounding of US-driven nanomaterials synthesis. Subsequently, the pros and cons of sono-nanotechnology and its advances in the synthesis of nanobiomaterials are drawn based on recent works. US-synthesised nanobiomaterials have improved properties and performance over conventional synthesis methods and most essentially eliminate the need for harsh and expensive chemicals. The sonoproduction of different classes and types of nanobiomaterials such as metal and superparamagnetic nanoparticles (NPs), lipid- and carbohydrate-based NPs, protein microspheres, microgels and other nanocomposites are broadly categorised based on the physical and/or chemical effects induced by US. This review ends on a good note and recognises US-driven synthesis as a pragmatic solution to satisfy the growing demand for nanobiomaterials, nonetheless some technical challenges are highlighted.
    Matched MeSH terms: Biocompatible Materials
  8. Fulltext Hybrid Collagen Hydrogel/Chondroitin-4-Sulphate Fortified with Dermal Fibroblast Conditioned Medium for Skin Therapeutic Application
    Maarof M, Mohd Nadzir M, Sin Mun L, Fauzi MB, Chowdhury SR, Idrus RBH, et al.
    Polymers (Basel), 2021 Feb 08;13(4).
    PMID: 33567703 DOI: 10.3390/polym13040508
    The current strategy for rapid wound healing treatment involves combining a biomaterial and cell-secreted proteins or biomolecules. This study was aimed at characterizing 3-dimensional (3D) collagen hydrogels fortified with dermal fibroblast-conditioned medium (DFCM) as a readily available acellular skin substitute. Confluent fibroblasts were cultured with serum-free keratinocyte-specific medium (KM1 and KM2) and fibroblast-specific medium (FM) to obtain DFCM. Subsequently, the DFCM was mixed with collagen (Col) hydrogel and chondroitin-4-sulphate (C4S) to fabricate 3D constructs termed Col/C4S/DFCM-KM1, Col/C4S/DFCM-KM2, and Col/C4S/DFCM-FM. The constructs successfully formed soft, semi-solid and translucent hydrogels within 1 h of incubation at 37 °C with strength of <2.5 Newton (N). The Col/C4S/DFCM demonstrated significantly lower turbidity compared to the control groups. The Col/C4S/DFCM also showed a lower percentage of porosity (KM1: 35.15 ± 9.76%; KM2: 6.85 ± 1.60%; FM: 14.14 ± 7.65%) compared to the Col (105.14 ± 11.87%) and Col/C4S (143.44 ± 27.72%) constructs. There were no changes in both swelling and degradation among all constructs. Fourier transform infrared spectrometry showed that all groups consisted of oxygen-hydrogen bonds (O-H) and amide I, II, and III. In conclusion, the Col/C4S/DFCM constructs maintain the characteristics of native collagen and can synergistically deliver essential biomolecules for future use in skin therapeutic applications.
    Matched MeSH terms: Biocompatible Materials
  9. Fulltext Synthesis, surface modification and characterisation of biocompatible magnetic iron oxide nanoparticles for biomedical applications
    Mahdavi M, Ahmad MB, Haron MJ, Namvar F, Nadi B, Rahman MZ, et al.
    Molecules, 2013 Jun 27;18(7):7533-48.
    PMID: 23807578 DOI: 10.3390/molecules18077533
    Superparamagnetic iron oxide nanoparticles (MNPs) with appropriate surface chemistry exhibit many interesting properties that can be exploited in a variety of biomedical applications such as magnetic resonance imaging contrast enhancement, tissue repair, hyperthermia, drug delivery and in cell separation. These applications required that the MNPs such as iron oxide Fe₃O₄ magnetic nanoparticles (Fe₃O₄ MNPs) having high magnetization values and particle size smaller than 100 nm. This paper reports the experimental detail for preparation of monodisperse oleic acid (OA)-coated Fe₃O₄ MNPs by chemical co-precipitation method to determine the optimum pH, initial temperature and stirring speed in order to obtain the MNPs with small particle size and size distribution that is needed for biomedical applications. The obtained nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). The results show that the particle size as well as the magnetization of the MNPs was very much dependent on pH, initial temperature of Fe²⁺ and Fe³⁺ solutions and steering speed. The monodisperse Fe₃O₄ MNPs coated with oleic acid with size of 7.8 ± 1.9 nm were successfully prepared at optimum pH 11, initial temperature of 45°C and at stirring rate of 800 rpm. FTIR and XRD data reveal that the oleic acid molecules were adsorbed on the magnetic nanoparticles by chemisorption. Analyses of TEM show the oleic acid provided the Fe₃O₄ particles with better dispersibility. The synthesized Fe₃O₄ nanoparticles exhibited superparamagnetic behavior and the saturation magnetization of the Fe₃O₄ nanoparticles increased with the particle size.
    Matched MeSH terms: Biocompatible Materials/administration & dosage; Biocompatible Materials/chemistry*
  10. Fulltext Physical properties and cytotoxicity comparison of experimental gypsum-based biomaterials with two current dental cement materials on L929 fibroblast cells
    Mahshim N, Reza F, Omar NS
    J Conserv Dent, 2013 Jul;16(4):331-5.
    PMID: 23956536 DOI: 10.4103/0972-0707.114364
    To evaluate physical properties and cytotoxicity of pure gypsum-based (pure-GYP) and experimental gypsum-based biomaterials mixed with polyacrylic acid (Gyp-PA). The results were compared with calcium hydroxide (CH) and glass ionomer cement (GIC) for application as base/liner materials.
    Matched MeSH terms: Biocompatible Materials
  11. Fulltext Cyclodextrin inclusion complex inhibits circulating galectin-3 and FGF-7 and affects the reproductive integrity and mobility of Caco-2 cells
    Maki MAA, Cheah SC, Bayazeid O, Kumar PV
    Sci Rep, 2020 10 15;10(1):17468.
    PMID: 33060727 DOI: 10.1038/s41598-020-74467-1
    Galectin-3 (Gal-3) is a carbohydrate-binding protein, that promotes angiogenesis through mediating angiogenic growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). There is strong evidence confirming FGF involvement in tumor growth and progression by disrupting cell proliferation and angiogenesis. In this study, we investigated the effect of β-cyclodextrin:everolimus:FGF-7 inclusion complex (Complex) on Caco-2 cell migration, cell motility and colony formation. In addition, we examined the inhibitory effect of the Complex on the circulating proteins; Gal-3 and FGF-7. Swiss Target Prediction concluded that Gal-3 and FGF are possible targets for β-CD. Results of the chemotaxis cell migration assay on Caco-2 cell line revealed that the Complex has higher reduction in cell migration (78.3%) compared to everolimus (EV) alone (58.4%) which is possibly due to the synergistic effect of these molecules when used as a combined treatment. Moreover, the Complex significantly decreased the cell motility in cell scratch assay, less than 10% recovery compared to the control which has ~ 45% recovery. The Complex inhibited colony formation by ~ 75% compared to the control. Moreover, the Complex has the ability to inhibit Gal-3 with minimum inhibitory concentration of 33.46 and 41 for β-CD and EV, respectively. Additionally, β-CD and β-CD:EV were able to bind to FGF-7 and decreased the level of FGF-7 more than 80% in cell supernatant. This confirms Swiss Target Prediction result that predicted β-CD could target FGF. These findings advance the understanding of the biological effects of the Complex which reduced cell migration, cell motility and colony formation and it is possibly due to inhibiting circulating proteins such as; Gal-3 and FGF-7.
    Matched MeSH terms: Biocompatible Materials
  12. Bioreactors Design, Types, Influencing Factors and Potential Application in Dentistry. A Literature Review
    Malhotra N
    Curr Stem Cell Res Ther, 2019;14(4):351-366.
    PMID: 30636614 DOI: 10.2174/1574888X14666190111105504
    OBJECTIVES: A variety of bioreactors and related approaches have been applied to dental tissues as their use has become more essential in the field of regenerative dentistry and dental tissue engineering. The review discusses the various types of bioreactors and their potential application in dentistry.

    METHODS: Review of the literature was conducted using keywords (and MeSH) like Bioreactor, Regenerative Dentistry, Fourth Factor, Stem Cells, etc., from the journals published in English. All the searched abstracts, published in indexed journals were read and reviewed to further refine the list of included articles. Based on the relevance of abstracts pertaining to the manuscript, full-text articles were assessed.

    RESULTS: Bioreactors provide a prerequisite platform to create, test, and validate the biomaterials and techniques proposed for dental tissue regeneration. Flow perfusion, rotational, spinner-flask, strain and customize-combined bioreactors have been applied for the regeneration of bone, periodontal ligament, gingiva, cementum, oral mucosa, temporomandibular joint and vascular tissues. Customized bioreactors can support cellular/biofilm growth as well as apply cyclic loading. Center of disease control & dip-flow biofilm-reactors and micro-bioreactor have been used to evaluate the biological properties of dental biomaterials, their performance assessment and interaction with biofilms. Few case reports have also applied the concept of in vivo bioreactor for the repair of musculoskeletal defects and used customdesigned bioreactor (Aastrom) to repair the defects of cleft-palate.

    CONCLUSIONS: Bioreactors provide a sterile simulated environment to support cellular differentiation for oro-dental regenerative applications. Also, bioreactors like, customized bioreactors for cyclic loading, biofilm reactors (CDC & drip-flow), and micro-bioreactor, can assess biological responses of dental biomaterials by simultaneously supporting cellular or biofilm growth and application of cyclic stresses.

    Matched MeSH terms: Biocompatible Materials
  13. The influence of topography on tissue engineering perspective
    Mansouri N, SamiraBagheri
    Mater Sci Eng C Mater Biol Appl, 2016 Apr 1;61:906-21.
    PMID: 26838922 DOI: 10.1016/j.msec.2015.12.094
    The actual in vivo tissue scaffold offers a three-dimensional (3D) structural support along with a nano-textured surfaces consist of a fibrous network in order to deliver cell adhesion and signaling. A scaffold is required, until the tissue is entirely regenerated or restored, to act as a temporary ingrowth template for cell proliferation and extracellular matrix (ECM) deposition. This review depicts some of the most significant three dimensional structure materials used as scaffolds in various tissue engineering application fields currently being employed to mimic in vivo features. Accordingly, some of the researchers' attempts have envisioned utilizing graphene for the fabrication of porous and flexible 3D scaffolds. The main focus of this paper is to evaluate the topographical and topological optimization of scaffolds for tissue engineering applications in order to improve scaffolds' mechanical performances.
    Matched MeSH terms: Biocompatible Materials/pharmacology; Biocompatible Materials/chemistry
  14. Fulltext Explorative Xylitol Detection from Lignocellulosic Biomass Fermentation of Coconut Husk Using HPLC C18 Column
    Mariam-Aisha Fatima, Muhammad Fahmi Mehdin, Nurain Nasrudin, Neelam Shahab
    Journal of Management & Science, 2018;16(2):29-38.
    MyJurnal
    Lignocellulosic biomass, found in wooden plant husks is a potent renewable material source which can be utilised to form various chemicals and biomaterials including polyols such as xylitol. Xylitol has been used commercially as an alternative to sucrose in many products as bulk sweetener in non-cariogenic confectionery as well as in diabetic diets and solutions for parenteral nutrition. Therefore, this study aims to optimise separation parameters of the Shimadzu high performance liquid chromatography (HPLC) (Model No: LC-20A) and quantify the potential of coconut husk as substrate for Candida albicans in producing xylitol using HPLC. Pretreatment to depolymerise components of biomass i.e. cellulose, hemicellulose and lignin were done using dilute acid hydrolysis method which yielded fermentable reducing sugars, xylose. Xylose is a monosaccharide with an aldehyde functional group, a reducing sugar which is then utilised and fermented by the yeast Candida albicans to form xylitol. In this study, the media used for fermenting pretreated coconut husk and Candida albicans is a synthetic defined (SD) minimal broth. Growth curves against concentration of reducing sugar were plotted to determine utilisation and production trends with specific mixes of carbon sources. The presence of reducing sugars were tested using 3,5-dinitrosalicylic acid (DNS) assay in pretreated coconut husk yielded 13.22 g/L. In order to analyse the product with HPLC, an existing protocol is modified for Hypersil GOLD™ C18 column with acetonitrile as the mobile phase. Results obtained from HPLC analyses using developed protocol suggested the formation of xylitol from the fermentation of pretreated husk by Candida albicans. These can be followed by purification of fermented media in obtaining a better separation of contaminating peaks.

    Matched MeSH terms: Biocompatible Materials
  15. Fulltext Analysis of machining pit by using electrical discharge machine die sinking
    Md Razak Daud, Wan Nor Shela Ezwane Wan Jusoh, Syahrullail Samion
    Journal of Engineering and Science Research, 2018;2(6):63-67.
    MyJurnal
    This study investigates metal removal rate (MRR) of the biomaterial by using discharge machine Neuar CNC A50 Electrical Discharge Machine Die Sinking (EDM DS). The purpose of this study is to compare machining curvature cup for material SKD 11 and stainless steel with shape curvature cup acetabular. The result showed that electrode wear is higher when high current is applied. For each applied current 0.5A and 3.0A could result electrode wear of 0.236 mm, 0.246 mm and 0.269 mm respectively. Mean time of complete discharged for each pit with 0.3mm depth with supply 0. 5A is 6.51 minutes; 1. 5A is 3.54 minutes and 3A is 1.52 minutes. The biggest mean parameter of the pit is 0.356 mm, with 3A of current is applied. From this study, it can be concluded that low current set may give lower electrode copper wear. The experiment will help a researcher to discharge biomaterial types of metal with small size of copper electrode use of EDM DS Neuar for discharge multi hole or micro pit.
    Matched MeSH terms: Biocompatible Materials
  16. Fulltext A novel design, analysis and 3D printing of Ti-6Al-4V alloy bio-inspired porous femoral stem
    Mehboob H, Tarlochan F, Mehboob A, Chang SH, Ramesh S, Harun WSW, et al.
    J Mater Sci Mater Med, 2020 Aug 20;31(9):78.
    PMID: 32816091 DOI: 10.1007/s10856-020-06420-7
    The current study is proposing a design envelope for porous Ti-6Al-4V alloy femoral stems to survive under fatigue loads. Numerical computational analysis of these stems with a body-centered-cube (BCC) structure is conducted in ABAQUS. Femoral stems without shell and with various outer dense shell thicknesses (0.5, 1.0, 1.5, and 2 mm) and inner cores (porosities of 90, 77, 63, 47, 30, and 18%) are analyzed. A design space (envelope) is derived by using stem stiffnesses close to that of the femur bone, maximum fatigue stresses of 0.3σys in the porous part, and endurance limits of the dense part of the stems. The Soderberg approach is successfully employed to compute the factor of safety Nf > 1.1. Fully porous stems without dense shells are concluded to fail under fatigue load. It is thus safe to use the porous stems with a shell thickness of 1.5 and 2 mm for all porosities (18-90%), 1 mm shell with 18 and 30% porosities, and 0.5 mm shell with 18% porosity. The reduction in stress shielding was achieved by 28%. Porous stems incorporated BCC structures with dense shells and beads were successfully printed.
    Matched MeSH terms: Biocompatible Materials/chemistry
  17. Fulltext Mechanical and in vitro biological performance of graphene nanoplatelets reinforced calcium silicate composite
    Mehrali M, Moghaddam E, Seyed Shirazi SF, Baradaran S, Mehrali M, Latibari ST, et al.
    PLoS One, 2014;9(9):e106802.
    PMID: 25229540 DOI: 10.1371/journal.pone.0106802
    Calcium silicate (CaSiO3, CS) ceramic composites reinforced with graphene nanoplatelets (GNP) were prepared using hot isostatic pressing (HIP) at 1150°C. Quantitative microstructural analysis suggests that GNP play a role in grain size and is responsible for the improved densification. Raman spectroscopy and scanning electron microscopy showed that GNP survived the harsh processing conditions of the selected HIP processing parameters. The uniform distribution of 1 wt.% GNP in the CS matrix, high densification and fine CS grain size help to improve the fracture toughness by ∼130%, hardness by ∼30% and brittleness index by ∼40% as compared to the CS matrix without GNP. The toughening mechanisms, such as crack bridging, pull-out, branching and deflection induced by GNP are observed and discussed. The GNP/CS composites exhibit good apatite-forming ability in the simulated body fluid (SBF). Our results indicate that the addition of GNP decreased pH value in SBF. Effect of addition of GNP on early adhesion and proliferation of human osteoblast cells (hFOB) was measured in vitro. The GNP/CS composites showed good biocompatibility and promoted cell viability and cell proliferation. The results indicated that the cell viability and proliferation are affected by time and concentration of GNP in the CS matrix.
    Matched MeSH terms: Biocompatible Materials/chemistry
  18. Synthesis, mechanical properties, and in vitro biocompatibility with osteoblasts of calcium silicate-reduced graphene oxide composites
    Mehrali M, Moghaddam E, Shirazi SF, Baradaran S, Mehrali M, Latibari ST, et al.
    ACS Appl Mater Interfaces, 2014 Mar 26;6(6):3947-62.
    PMID: 24588873 DOI: 10.1021/am500845x
    Calcium silicate (CaSiO3, CS) ceramics are promising bioactive materials for bone tissue engineering, particularly for bone repair. However, the low toughness of CS limits its application in load-bearing conditions. Recent findings indicating the promising biocompatibility of graphene imply that graphene can be used as an additive to improve the mechanical properties of composites. Here, we report a simple method for the synthesis of calcium silicate/reduced graphene oxide (CS/rGO) composites using a hydrothermal approach followed by hot isostatic pressing (HIP). Adding rGO to pure CS increased the hardness of the material by ∼40%, the elastic modulus by ∼52%, and the fracture toughness by ∼123%. Different toughening mechanisms were observed including crack bridging, crack branching, crack deflection, and rGO pull-out, thus increasing the resistance to crack propagation and leading to a considerable improvement in the fracture toughness of the composites. The formation of bone-like apatite on a range of CS/rGO composites with rGO weight percentages ranging from 0 to 1.5 has been investigated in simulated body fluid (SBF). The presence of a bone-like apatite layer on the composite surface after soaking in SBF was demonstrated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The biocompatibility of the CS/rGO composites was characterized using methyl thiazole tetrazolium (MTT) assays in vitro. The cell adhesion results showed that human osteoblast cells (hFOB) can adhere to and develop on the CS/rGO composites. In addition, the proliferation rate and alkaline phosphatase (ALP) activity of cells on the CS/rGO composites were improved compared with the pure CS ceramics. These results suggest that calcium silicate/reduced graphene oxide composites are promising materials for biomedical applications.
    Matched MeSH terms: Biocompatible Materials/chemical synthesis; Biocompatible Materials/chemistry*
  19. Dental implants from functionally graded materials
    Mehrali M, Shirazi FS, Mehrali M, Metselaar HS, Kadri NA, Osman NA
    J Biomed Mater Res A, 2013 Oct;101(10):3046-57.
    PMID: 23754641 DOI: 10.1002/jbm.a.34588
    Functionally graded material (FGM) is a heterogeneous composite material including a number of constituents that exhibit a compositional gradient from one surface of the material to the other subsequently, resulting in a material with continuously varying properties in the thickness direction. FGMs are gaining attention for biomedical applications, especially for implants, owing to their reported superior composition. Dental implants can be functionally graded to create an optimized mechanical behavior and achieve the intended biocompatibility and osseointegration improvement. This review presents a comprehensive summary of biomaterials and manufacturing techniques researchers employ throughout the world. Generally, FGM and FGM porous biomaterials are more difficult to fabricate than uniform or homogenous biomaterials. Therefore, our discussion is intended to give the readers about successful and obstacles fabrication of FGM and porous FGM in dental implants that will bring state-of-the-art technology to the bedside and develop quality of life and present standards of care.
    Matched MeSH terms: Biocompatible Materials/pharmacology*; Biocompatible Materials/chemistry*
  20. Nanoreinforced Hydrogels for Tissue Engineering: Biomaterials that are Compatible with Load-Bearing and Electroactive Tissues
    Mehrali M, Thakur A, Pennisi CP, Talebian S, Arpanaei A, Nikkhah M, et al.
    Adv Mater, 2017 Feb;29(8).
    PMID: 27966826 DOI: 10.1002/adma.201603612
    Given their highly porous nature and excellent water retention, hydrogel-based biomaterials can mimic critical properties of the native cellular environment. However, their potential to emulate the electromechanical milieu of native tissues or conform well with the curved topology of human organs needs to be further explored to address a broad range of physiological demands of the body. In this regard, the incorporation of nanomaterials within hydrogels has shown great promise, as a simple one-step approach, to generate multifunctional scaffolds with previously unattainable biological, mechanical, and electrical properties. Here, recent advances in the fabrication and application of nanocomposite hydrogels in tissue engineering applications are described, with specific attention toward skeletal and electroactive tissues, such as cardiac, nerve, bone, cartilage, and skeletal muscle. Additionally, some potential uses of nanoreinforced hydrogels within the emerging disciplines of cyborganics, bionics, and soft biorobotics are highlighted.
    Matched MeSH terms: Biocompatible Materials
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