1186 results found
Alonso Frank M, Meltzer C, Braunschweig B, et al., 2017, Functionalization of steel surfaces with organic acids: Influence on wetting and corrosion behavior, Applied Surface Science, Vol: 404, Pages: 326-333, ISSN: 0169-4332
Araújo M, Viveiros R, Philippart A, et al., 2017, Bioactivity, mechanical properties and drug delivery ability of bioactive glass-ceramic scaffolds coated with a natural-derived polymer., Mater Sci Eng C Mater Biol Appl, Vol: 77, Pages: 342-351
In this work, hybrid melanin-coated bioactive glass-ceramic multifunctional scaffolds were developed and characterized in terms of mechanical strength, in vitro bioactivity in simulated body fluid (SBF) and ability to load ibuprofen. The coated scaffolds exhibited an accelerated bioactivity in comparison with the uncoated ones, being able of developing hydroxyapatite-like crystals after 7days soaking in simulated body fluid (SBF). Besides its positive influence on the scaffolds bioactivity, the melanin coating was able to enhance their mechanical properties, increasing the initial compressive strength by a factor of >2.5. Furthermore, ibuprofen was successfully loaded on this coating, allowing a controlled drug release of the anti-inflammatory agent.
Atiq Ur Rehman M, Bastan FE, Haider B, et al., 2017, Electrophoretic deposition of PEEK/bioactive glass composite coatings for orthopedic implants: A design of experiments (DoE) study, Materials and Design, Vol: 130, Pages: 223-230, ISSN: 0264-1275
© 2017 Elsevier Ltd This paper presents a study on the Design of Experiments (DoE) approach to optimize the electrophoretic deposition (EPD) process parameters for PEEK base coatings. PEEK and bioactive glass (45S5 BG) particles were suspended in ethanol and suspensions were stabilized with the help of citric acid. Electric field related parameters were optimized by using Taguchi DoE; an orthogonal array of L15 type with mixed levels of the control factors. Statistical tools were employed to identify the significant factors affecting deposition rate and to quantify the reproducibility of the constant voltage EPD process. It was demonstrated that both deposition voltage and time significantly influence deposition rate. Moreover, statistical confidence was elucidated by Defect Per Million Opportunities (DPMO) model, as proposed in six sigma tools. A pronounced deposition rate was obtained at 100 V/cm in comparison to 110 V/cm, although the adhesion strength and microstructural homogeneity were lower for 100 V/cm. The optimal suspension composition and EPD conditions predicted by DoE were further verified by experiments and qualitative agreement was found between the predicted and experimental data. The experimental results and statistical analyses are discussed based on current knowledge of the EPD of ceramic materials and their co-deposition with polymeric particles.
Balasubramanian P, Hupa L, Jokic B, et al., 2017, Angiogenic potential of boron-containing bioactive glasses: in vitro study, Journal of Materials Science, Vol: 52, Pages: 8785-8792, ISSN: 0022-2461
Bejarano J, Detsch R, Boccaccini AR, et al., 2017, PDLLA scaffolds with Cu- and Zn-doped bioactive glasses having multifunctional properties for bone regeneration., J Biomed Mater Res A, Vol: 105, Pages: 746-756
Novel multifunctional scaffolds for bone regeneration can be developed by incorporation of bioactive glasses (BG) doped with therapeutic and antibacterial metal ions, such as copper (Cu) and zinc (Zn), into a biodegradable polymer. In this context, porous composite materials of biodegradable poly(d, l-lactide) (PDLLA) mixed with sol-gel BG of chemical composition 60SiO2 ; 25CaO; 11Na2 O; and 4P2 O5 (mol %) doped with either 1 mol % of CuO or ZnO, and with both metals, were prepared. The cytocompatibility of the scaffolds on bone marrow stromal cells (ST-2) depended on both, the amount of glass filler and the concentration of metal ion, as evaluated by lactate dehydrogenase (LDH) activity, cell viability (water-soluble tetrazolium salt [WST-8]), and by cell morphology (scanning electron microscopy [SEM]) tests. In particular, scaffolds having a filler content of 10 wt % showed the highest cytocompatibility. In addition, compared to the neat polymer, the scaffolds containing Cu promoted the angiogenesis marker (Vascular endothelial growth factor concentration) to a larger extent while scaffolds containing Zn increased the osteogenesis marker (specific alkaline phosphatase-activity). Noteworthy, the scaffolds with both metal ions showed a combined effect on both properties. Cu- and Zn-doped glasses also provided higher antibacterial capacity to PDLLA-based scaffolds against methicillin-resistant S. aureus bacteria than undoped glass. In combination, our results showed that by a proper addition of Cu- and Zn-doped BG to a PDLLA matrix, multifunctional composite scaffolds with enhanced biological activity can be designed for bone tissue regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 746-756, 2017.
Bertolla L, Dlouhý I, Tatarko P, et al., 2017, Pressureless spark plasma–sintered Bioglass<sup>®</sup> 45S5 with enhanced mechanical properties and stress–induced new phase formation, Journal of the European Ceramic Society, Vol: 37, Pages: 2727-2736, ISSN: 0955-2219
Boccaccini AR, 2017, Editorial Note, Materials Letters, Vol: 197, ISSN: 0167-577X
Boccaccini AR, Brauer DS, Hupa L, 2017, Preface
Boccaccini AR, Willoughby A, 2017, The 35th anniversary of Materials Letters, Materials Letters, ISSN: 0167-577X
Boccardi E, Ciraldo FE, Boccaccini AR, 2017, Bioactive glass-ceramic scaffolds: Processing and properties, MRS Bulletin, Vol: 42, Pages: 226-232, ISSN: 0883-7694
© 2017 Materials Research Society. Bioactive glasses and related bioactive glass-ceramics have been used for over three decades in biomedical applications such as bulk, particulate, or coatings materials. More recently, highly porous bioactive glass-ceramic scaffolds for bone-Tissue engineering have also been developed from selected compositions of bioactive glasses. Current bioactive glass-ceramic scaffolds are characterized by an open porous network, high bioactivity, and mechanical properties similar to those of trabecular bone. This article reviews the latest achievements in the development of porous bioactive glass-ceramics intended for bone-Tissue engineering applications, highlighting the fabrication technologies and scaffold properties. Improvements in the mechanical properties of bioactive glass-ceramic scaffolds exhibiting high bioactivity have been achieved by different approaches in the last 10 years. Relevant long-Term in vivo studies are required to confirm the suitability of such bioactive glass-ceramic scaffolds in clinical applications.
Cordero-Arias L, Boccaccini AR, 2017, Electrophoretic deposition of chondroitin sulfate-chitosan/bioactive glass composite coatings with multilayer design, Surface and Coatings Technology, Vol: 315, Pages: 417-425, ISSN: 0257-8972
© 2017 Elsevier B.V. Novel chondroitin sulfate (CS) based coatings were produced by electrophoretic deposition (EPD). CS was used as matrix and combined with bioactive glass (BG) particles to produce a series of bioactive composite coatings with potential for orthopedic and dental applications. Furthermore multilayer systems incorporating chitosan were designed and developed to tailor coating composition, bioactivity and degradation. Solutions and suspensions based on CS were developed, and their stability analyzed by means of ζ–potential measurements. EPD conditions (concentration, potential and deposition time) were investigated and determined for CS and BG/CS coatings, as well as for a variety of multilayer systems. Coating morphology, microstructure and composition were studied using SEM, XRD, FTIR spectroscopy and TG-DTA techniques which confirmed the formation of a variety of homogeneous CS based multilayered coatings. Finally, immersion test in simulated body fluid was carried out demonstrating the bioactive behavior of some of the new systems developed after 2 days of immersion. CS containing coatings are of interest for applications where the combined effects of CS and BG can lead to enhanced tissue regeneration effects.
Considerable research efforts have been devoted to zein-based biomaterials for tissue engineering and other biomedical applications over the past decade. The attention given to zein-based polymers is primarily attributed to their biocompatibility and biodegradability. However, due to the relatively low mechanical properties of these polymers, numerous inorganic compounds (e.g., hydroxyapatite, calcium phosphate, bioactive glasses, natural clays) have been considered in combination with zein to create composite materials in an attempt to enhance zein mechanical properties. Inorganic phases also positively impact on the hydrophilic properties of zein matrices inducing a suitable environment for cell attachment, spreading, and proliferation. This review covers available literature on zein and zein-based composite materials, with focus on the combination of zein with commonly used inorganic fillers for tissue engineering and drug delivery applications. An overview of the most recent advances in fabrication techniques for zein-based composites is presented and key applications areas and future developments in the field are highlighted. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1656-1665, 2017.
Dippold D, Cai A, Hardt M, et al., 2017, Novel approach towards aligned PCL-Collagen nanofibrous constructs from a benign solvent system., Mater Sci Eng C Mater Biol Appl, Vol: 72, Pages: 278-283
Under several conditions such as severe trauma skeletal muscle lack the ability to reorganize and the loss of muscle function is inevitable. The application of tissue engineered constructs is a promising approach in regenerative therapies for damaged muscular tissue. Therefore, the development of highly aligned scaffolds based on polycaprolactone (PCL) has been studied extensively. Nanofiber scaffolds containing collagen have mostly been fabricated via electrospinning using highly corrosive 1,1,1,3,3,3 hexafluoro-2-propanol (HFIP) so far. In this study, aligned Polycaprolactone-Collagen (PCL-Coll) biocomposite nanofibers were fabricated via electrospinning using environmentally benign diluted acetic acid (AcOH) as solvent. Furthermore, ultrasonic treatment was introduced to enhance the intrinsically weak solubility of PCL in AcOH. AcOH was diluted to an ideal concentration for electrospinning of 90%. The final solutions were spun at various conditions and collected with different collector setups in order to determine ideal processing conditions for the fabrication of highly aligned nanofibers.
Ege D, Duru I, Kamali AR, et al., 2017, Nitride, Zirconia, Alumina, and Carbide Coatings on Ti6Al4V Femoral Heads: Effect of Deposition Techniques on Mechanical and Tribological Properties, Advanced Engineering Materials, ISSN: 1438-1656
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Ti6Al4V has been extensively studied in orthopedic applications because of its biocompatibility, desirable mechanical strength, and fatigue resistance. A wide range of bioinert ceramics have been investigated to further develop the tribological and mechanical properties of Ti6Al4V for the production of potential femoral heads. However, an analysis of the literature indicates that the performance of the coatings produced has been inconsistent. In this review, for the first-time deposition techniques of the most widely studied bioinert ceramics namely nitrides, carbides, zirconia, and alumina on Ti6Al4V substrates and their relevant mechanical and tribological performance have been analyzed. Finally, graphene has also been suggested for use together with bioinert ceramics due to its excellent mechanical and physical properties for coating Ti6Al4V femoral heads.
Fiocco L, Elsayed H, Badocco D, et al., 2017, Direct ink writing of silica-bonded calcite scaffolds from preceramic polymers and fillers., Biofabrication, Vol: 9
Silica-bonded calcite scaffolds have been successfully 3D-printed by direct ink writing, starting from a paste comprising a silicone polymer and calcite powders, calibrated in order to match a SiO2/CaCO3 weight balance of 35/65. The scaffolds, fabricated with two slightly different geometries, were first cross-linked at 350 °C, then fired at 600 °C, in air. The low temperature adopted for the conversion of the polymer into amorphous silica, by thermo-oxidative decomposition, prevented the decomposition of calcite. The obtained silica-bonded calcite scaffolds featured open porosity of about 56%-64% and compressive strength of about 2.9-5.5 MPa, depending on the geometry. Dissolution studies in SBF and preliminary cell culture tests, with bone marrow stromal cells, confirmed the in vitro bioactivity of the scaffolds and their biocompatibility. The seeded cells were found to be alive, well anchored and spread on the samples surface. The new silica-calcite composites are expected to be suitable candidates as tissue-engineering 3D scaffolds for regeneration of cancellous bone defects.
Galarraga-Vinueza ME, Mesquita-Guimarães J, Magini RS, et al., 2017, Anti-biofilm properties of bioactive glasses embedding organic active compounds., J Biomed Mater Res A, Vol: 105, Pages: 672-679
Bioactive glasses (BGs) are promising materials for bone repair due to their desirable properties such as osteoconductivity, biodegradability, angiogenic potential, and antibacterial activity. Ionic dissolution products from bioactive glasses increase the medium pH inhibiting surrounding bacteria proliferation. The activity of BGs against biofilm formation has been enhanced by incorporating organic antibacterial compounds. The aim of this review was to summarize evidence in literature which assesses the efficacy of antibacterial and anti-biofilm compounds embedded in bioactive glasses to prevent peri-implant infection during bone healing. A PubMed bibliographical research was carried out including articles published in the last 20 years. Most previous studies evaluated antibacterial efficiency in planktonic cultures but did not investigate biofilm inhibition, underestimating biofilm clinical relevance. Multifactorial features such as biocompatibility of embedded compounds, receptor site characteristics, and drug delivery efficiency have been found to influence the bioactive glass capability of acting both as an anti-biofilm agent and as a bone repairing biomaterial. Accordingly, further in vitro and in vivo studies are required to select the most promising anti-biofilm agents which should be incorporated into bioactive glasses to counteract biofilm proliferation, without inducing toxic effects on human cells, and with the added functionality of promoting bone regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 672-679, 2017.
Germaini MM, Detsch R, Grünewald A, et al., 2017, Osteoblast and osteoclast responses to A/B type carbonate-substituted hydroxyapatite ceramics for bone regeneration., Biomed Mater, Vol: 12
The influence of carbonate substitution (4.4 wt%, mixed A/B type) in hydroxyapatite ceramics for bone remodeling scaffolds was investigated by separately analyzing the response of pre-osteoblasts and osteoclast-like cells. Carbonated hydroxyapatite (CHA) (Ca9.5(PO4)5.5(CO3)0.5(OH)(CO3)0.25-CHA), mimicking the chemical composition of natural bone mineral, and pure hydroxyapatite (HA) (Ca10(PO4)6(OH)2-HA) porous ceramics were processed to obtain a similar microstructure and surface physico-chemical properties (grain size, porosity ratio and pore size, surface roughness and zeta potential). The biological behavior was studied using MC3T3-E1 pre-osteoblastic and RAW 264.7 monocyte/macrophage cell lines. Chemical dissolution in the culture media and resorption lacunae produced by osteoclasts occur with both HA and CHA ceramics, but CHA exhibits much higher dissolution and greater bioresorption ability. CHA ceramics promoted a significantly higher level of pre-osteoblast proliferation. Osteoblastic differentiation, assessed by qRT-PCR of RUNX2 and COLIA2, and pre-osteoclastic proliferation and differentiation were not significantly different on CHA or HA ceramics but cell viability and metabolism were significantly greater on CHA ceramics. Thus, the activity of both osteoclast-like and osteoblastic cells was influenced by the carbonate substitution in the apatite structure. Furthermore, CHA showed a particularly interesting balance between biodegradation, by osteoclasts and chemical dissolution, and osteogenesis through osteoblasts' activity, to stimulate bone regeneration. It is hypothesized that this amount of 4.4 wt% carbonate substitution leads to an adapted concentration of calcium in the fluid surrounding the ceramic to stimulate the activity of cells. These results highlight the superior biological behavior of microporous 4.4 wt% A/B CHA ceramics that could beneficially replace the commonly used HA of biphasic calcium phosphates for future applications in bone
Heise S, Höhlinger M, Hernández YT, et al., 2017, Electrophoretic deposition and characterization of chitosan/bioactive glass composite coatings on Mg alloy substrates, Electrochimica Acta, Vol: 232, Pages: 456-464, ISSN: 0013-4686
Hochleitner G, Kessler M, Schmitz M, et al., 2017, Melt electrospinning writing of defined scaffolds using polylactide-poly(ethylene glycol) blends with 45S5 bioactive glass particles, Materials Letters, Vol: 205, Pages: 257-260, ISSN: 0167-577X
© 2017 The Authors Advances in Tissue Engineering (TE) demand strategies to apply new biomaterials and processing technologies. In this context, especially computer aided additive manufacturing (AM) has turned out as a promising tool to tailor scaffold architectures with high precision. However, there is currently a lack of appropriate AM methods, since the majority face serious drawbacks regarding printing accuracy and speed, as well as limitations regarding the range of applicable biomaterials. Here, we present the simple AM processing of poly(lactide-block-ethylene glycol-block-lactide) (PLA-PEG-PLA) triblock copolymers via melt electrospinning writing (MEW). Furthermore, we demonstrate the accurate deposition of fibers (fØ = 31 ± 2 µm) made of copolymer blends with low-molecular PLA incorporating solid 45S5 bioactive glass (BG) particles. Thus, we introduce MEW for the printing of highly porous, particle loaded scaffolds with micron-sized composite fibers with potential application in bone TE.
Hoppe A, Boccaccini AR, 2017, Chapter 16: Bioactive Glasses as Carriers of Therapeutic Ions and the Biological Implications, RSC Smart Materials, Pages: 362-392
Höhlinger M, Heise S, Wagener V, et al., 2017, Developing surface pre-treatments for electrophoretic deposition of biofunctional chitosan-bioactive glass coatings on a WE43 magnesium alloy, Applied Surface Science, Vol: 405, Pages: 441-448, ISSN: 0169-4332
© 2017 American Chemical Society. Metastable nanoparticles of vaterite were formed using a simple ultrasound technique. The effects of ultrasound amplitude and duration, as well as solution concentration, were investigated. The produced particles were characterized using standard X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning and transmission electron microscopies (SEM and TEM, respectively). As expected, the ultrasound synthesis process caused the particle size to be smaller than with conventional (magnetic bar) stirring, and allowed for the reaction time to be shortened as the crystallization rate was increased. As shown by XRD, FTIR, and SEM, the ultrasound process also led to the formation of pure vaterite, though the presence of calcite occurred as the ultrasound power was reduced and the pulse time increased. For both conventional and ultrasound techniques, the particle size was reduced with an increase in starting solution concentration. Using this technique allows for reproducible, tailored calcium carbonate particles for controlled drug delivery, as well as for use in composites for soft tissue repair; in particular, when used as the filler during electrospinning and melt electrospinning.
Karbowniczek J, Cordero-Arias L, Virtanen S, et al., 2017, Electrophoretic deposition of organic/inorganic composite coatings containing ZnO nanoparticles exhibiting antibacterial properties., Mater Sci Eng C Mater Biol Appl, Vol: 77, Pages: 780-789
To address one of the serious problems associated with permanent implants, namely bacterial infections, novel organic/inorganic coatings containing zinc oxide nanoparticles (nZnO) are proposed. Coatings were obtained by electrophoretic deposition (EPD) on stainless steel 316L. Different deposition conditions namely: deposition times in the range 60-300s and applied voltage in the range 5-30V as well as developing a layered coating approach were studied. Antibacterial tests against gram-positive Staphylococcus aureus and gram-negative Salmonella enteric bacteria confirmed the activity of nZnO to prevent bacterial growth. Coatings composition and morphology were analyzed by thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. Moreover, the corrosion resistance was analyzed by evaluation of the polarization curves in DMEM at 37°C, and it was found that coatings containing nZnO increased the corrosion resistance compared to the bare substrate. Considering all results, the newly developed coatings represent a suitable alternative for the surface modification of metallic implants.
Kaya S, Boccaccini AR, 2017, Electrophoretic deposition of zein coatings, Journal of Coatings Technology Research, Vol: 14, Pages: 683-689, ISSN: 1547-0091
Macías-Andrés VI, Li W, Aguilar-Reyes EA, et al., 2017, Preparation and characterization of 45S5 bioactive glass-based scaffolds loaded with PHBV microspheres with daidzein release function., J Biomed Mater Res A, Vol: 105, Pages: 1765-1774
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microsphere loaded 45S5 bioactive glass (BG) based scaffolds with drug releasing capability have been developed. PHBV microspheres with a mean particle size 4 ± 2 μm loaded with daidzein were obtained by oil-in-water single emulsion solvent evaporation method and applied to the surface of BG scaffolds by dip coating technique. The morphology, in vitro bioactivity in simulated body fluid (SBF), mechanical properties and drug release kinetics of microsphere loaded scaffolds were studied. The microspheres were shown to be homogeneously dispersed on the scaffold surfaces. It was confirmed that hydroxyapatite crystals homogeneously grew not only on the surface of the scaffold but also on the surface of the microspheres within 3 days of immersion in SBF. The daidzein release from the microsphere loaded scaffolds lasted almost 1 month and was determined to be diffusion controlled. The microsphere loaded BG scaffolds with daidzein releasing capability obtained in this study are a candidate for bone tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1765-1774, 2017.
Meincke T, Pacheco VM, Hoffmann D, et al., 2017, Engineering the surface functionality of 45S5 bioactive glass-based scaffolds by the heterogeneous nucleation and growth of silver particles, Journal of Materials Science, Vol: 52, Pages: 9082-9090, ISSN: 0022-2461
Mesquita-Guimarães J, Leite MA, Souza JC, et al., 2017, Processing and strengthening of 58S bioactive glass-infiltrated titania scaffolds., J Biomed Mater Res A, Vol: 105, Pages: 590-600
In this work, TiO2 ceramic scaffolds were fabricated by the replica method using polyurethane (PU) sponges. Suspensions with high solid content were used to achieve scaffolds with improved mechanical behavior. TiO2 ceramic suspensions were optimized by rheological studies using different additives. It was found that the composition with 0.5 wt % Darvan enhanced the covering of the sponge struts. PU sponges of 45 to 80 ppi (pore per inch) were well coated without clogging pores. A thermal treatment with varying holding times, temperatures and heating rates was adjusted. The influence of different pore sizes on mechanical strength was evaluated. It was possible to obtain TiO2 scaffolds with 90% porosity and high pore interconnectivity, having compressive strength exceeding 0.6 MPa. TiO2 scaffolds were filled up with a 58S bioactive glass suspension to impart bioactive character to the scaffolds. These hybrid structures presented mechanical strengthening of about 26-213% depending on their sponge porosity. The prediction for cells viability via zeta potential measures indicated that this hybrid material is very promising for scaffold application with -19 to -25 mV between pH of 7.35-7.45. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 590-600, 2017.
Miguez-Pacheco V, Gorustovich AA, Boccaccini AR, et al., 2017, Chapter 15: Bioactive Glasses for Soft Tissue Engineering Applications, RSC Smart Materials, Pages: 336-361
Moura D, Souza MT, Liverani L, et al., 2017, Development of a bioactive glass-polymer composite for wound healing applications., Mater Sci Eng C Mater Biol Appl, Vol: 76, Pages: 224-232
This study reports the production and characterization of a composite material for wound healing applications. A bioactive glass obtained by sol-gel process and doped with two different metal ions was investigated. Silver (Ag) and cobalt (Co) were chosen due to their antibacterial and angiogenic properties, respectively, very beneficial in the wound healing process. Poly(ε-caprolactone) (PCL) fibers were produced by electrospinning (ES) from a polymeric solution using acetone as a solvent. After optimization of the ES parameters, two main suspensions were prepared, namely: PCL containing bioactive glass nanoparticles (BG-NP) and PCL with Ag2O and CoO doped BG-NP (DP BG-NP), which were processed with different concentrations of BG-NP (0.25%, 0.5% and 0.75wt%). The composite membranes were characterized in terms of morphology, fiber diameter, weight loss, mineralization potential and mechanical performance.
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