bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and in vitro characterization of biomorphic silk fibroin scaffolds for bone tissue engineering
Authors: Qian Junmin , Suo Aili , Jin Xinxia , Xu Weijun , Xu Minghui 
Published: October 2013

AbstractIn bone tissue engineering, a qualified scaffold should provide a three‐dimensional porous structure mimicking the extracellular matrix of bone except good biological properties. In this study, biomorphic silk fibroin (SF) scaffolds were fabricated from cane by an innovative biotemplating‐negative mold process. The physicochemical properties, in vitro enzymatic degradation behavior and biocompatibility of the biomorphic SF scaffolds were investigated. The results showed that the scaffolds well inherited the original porous morphology of cane, and possessed good mechanical stability. The scaffolds had a compressive modulus of 1.56 ± 0.08 MPa and a porosity of 82.73%, and exhibited a bimodal pore size distribution (15 and 172 μm). The degradation ratio of the SF scaffolds increased with prolonging degradation time and reached 29% within 21 days when exposed to 1.0 U/mL collagenase IA. The in vitro cytocompatibility evaluation indicated that the scaffolds could support cell attachment, proliferation, and osteogenic differentiation of osteoblast‐like MC3T3‐E1 cells, as assessed by SEM, fluorescent staining, MTT, and ALP activity assays. The results indicated the potential of biomorphic SF scaffolds for bone tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2961–2971, 2014.
Effect of geometry and microstructure of honeycomb TCP scaffolds on bone regeneration
Authors: Takabatake Kiyofumi , Yamachika Eiki , Tsujigiwa Hidetsugu , Takeda Yasushi , Kimura Mariko , Takagi Shin , Nagatsuka Hitoshi , Iida Seiji 
Published: October 2013

AbstractIn recent years, artificial biological materials have been commonly used for the treatment of bone tissue defects caused by trauma, tumors, or surgical stress. Although tricalcium phosphate (TCP) is a promising absorbent bone tissue reconstruction biomaterial, it has been reported that its biocompatibility and osteoconductivity depend on its preparation method and sintering temperature. In addition, although it is thought that the microenvironment produced by the extracellular matrix plays an important role in cell growth and differentiation, there have been few studies on how the geometric structure of artificial biological materials affects cells. In the present study, a new honeycomb TCP scaffold containing through‐holes with diameters of 300 µm has been developed. The influence of the sintering temperature on the crystal structure and material properties of the honeycomb TCP scaffold was investigated using scanning electron microscopy and X‐ray diffraction. Its biocompatibility and osteoconductivity were also evaluated by implantation into experimental animals. It was found that a β‐TCP scaffold sintered at 1200°C exhibited high biocompatibility and osteoconductivity, and when it was loaded with BMP‐2, it exhibited both osteoconductivity and osteoinductivity, promoting rapid bone formation in both ectopic and orthotopic areas. It is thus a highly promising bone reconstruction material that is expected to find clinical applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2952–2960, 2014.
Two‐stage implantation of the skin‐ and bone‐integrated pylon seeded with autologous fibroblasts induced into osteoblast differentiation for direct skeletal attachment of limb prostheses
Authors: Shevtsov Maxim A. , Galibin Oleg V. , Yudintceva Nataliya M. , Blinova Miralda I. , Pinaev George P. , Ivanova Anna A. , Savchenko Olga N. , Suslov Dmitriy N. , Potokin Igor L. , Pitkin Emil , Raykhtsaum Grigory , Pitkin Mark R. 
Published: October 2013

AbstractAngio‐ and osteogenesis following the two‐stage (TS) implantation of the skin‐ and bone‐integrated pylon seeded with autologous fibroblasts was evaluated. Two consecutive animal substudies were undertaken: intramedullary subcutaneous implantation (15 rabbits) and a TS transcutaneous implantation (12 rabbits). We observed enhanced osseointegrative properties of the intramedullary porous component seeded with fibroblasts induced into osteoblast differentiation, as compared to the untreated porous titanium pylon. The three‐phase scintigraphy and subsequent histological analysis showed that the level of osteogenesis was 1.5‐fold higher than in the control group, and significantly so (p < 0.05). The biocompatibility was further proved by the absence of inflammatory response or encapsulation and sequestration on the histology assay. Treatment of the transcutaneous component with autologous fibroblasts was associated with nearly a 2‐fold decrease in the period required for the ingrowth of dermal and subdermal soft tissues into the implant surface, as compared to the untreated porous titanium component. Direct dermal attachment to the transcutaneous implant prevented superficial and deep periprosthetic infections in rabbits in vivo. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3033–3048, 2014.
Effect of UV‐irradiation intensity on graft polymerization of 2‐methacryloyloxyethyl phosphorylcholine on orthopedic bearing substrate
Authors: Kyomoto Masayuki , Moro Toru , Yamane Shihori , Hashimoto Masami , Takatori Yoshio , Ishihara Kazuhiko 
Published: October 2013

AbstractPhotoinduced grafting of 2‐methacryloyloxyethyl phosphorylcholine (MPC) onto cross‐linked polyethylene (CLPE) was investigated for its ability to reduce the wear of orthopedic bearings. We investigated the effect of UV‐irradiation intensity on the extent of poly(MPC) (PMPC) grafting, and found that it increased with increasing intensity up to 7.5 mW/cm2, and the remained fairly constant. It was found to be extremely important to carefully control the UV intensity, as at higher values, a PMPC gel formed via homopolymerization of the MPC, resulting in the formation of cracks at the interface of the PMPC layer and the CLPE substrate. When the CLPE was exposed to UV‐irradiation during the graft polymerization process, some of its physical and mechanical properties were slightly changed due to cross‐linking and scission effects in the surface region; however, the results of all of the tests exceed the lower limits of the ASTM standards. Modification of the CLPE surface with the hydrophilic PMPC layer increased lubrication to levels that match articular cartilage. The highly hydrated thin PMPC films mimicked the native cartilage extracellular matrix that covers synovial joint surface, acting as an extremely efficient lubricant, and providing high‐wear resistance. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3012–3023, 2014.
A self‐healing biomaterial based on free‐radical polymerization
Authors: Dailey Mary M. Caruso , Silvia Alexander W. , McIntire Patrick J. , Wilson Gerald O. , Moore Jeffrey S. , White Scott R. 
Published: October 2013

AbstractSelf‐healing chemistry used for damage repair have not previously been demonstrated for free‐radical polymerization pathways. However, this chemistry is important for addition polymers such as poly(methyl methacrylate) used in bone cement and epoxy vinyl ester used in dental resins. Self‐healing biomaterials offer the potential for safer and longer lasting implants and restoratives by slowing or arresting crack damage. In the free‐radical self‐healing system reported here, the three components required for polymerization (free‐radical peroxide initiator, tertiary amine activator, and vinyl acrylate monomers) are compartmentalized into two separate microcapsules—one containing the peroxide initiator, and the other containing both monomer and activator. Crack damage ruptures the capsules so that the three components mix and react to form a new polymer that effectively rebonds the crack and restores approximately 75% of the original fracture toughness. Optimal healing is obtained by a systematic evaluation of the effect of monomer, initiator, and activator concentration on healing performance. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3024–3032, 2014.
Hyaluronic acid‐based nanocomposite hydrogels for ocular drug delivery applications
Authors: Widjaja Leonardus Kresna , Bora Meghali , Chan Paul Ng Poh Huat , Lipik Vitali , Wong Tina T. L. , Venkatraman Subbu S. 
Published: October 2013

AbstractHyaluronic acid (HA) is a widely investigated biomaterial for many therapeutic applications owing to its unique properties of biocompatibility, biodegradation, and viscoelasticity. HA being a natural component of eye tissue with significant role in wound healing is a natural choice as a carrier for ocular drug delivery, provided the incorporated drugs are released in a sustained manner. However, localized sustained release of drugs inside eye has been difficult to achieve because of the inability to retain carriers for long periods in the eye. Using noncrosslinked (soluble) HA offers limited control over site retention of drugs. In order to obtain prolonged sustained delivery, two HA‐based composite hydrogels incorporating nanocarriers, have been synthesized and characterized for swelling, rheology, degradation, and in vitro release of latanoprost, a drug used to reduce intraocular pressure. The HA is first chemically modified, mixed with drug‐loaded liposomes, and then crosslinked to obtain nanocomposite hydrogels. In vitro release study shows longer sustained release of latanoprost from composite hydrogels as compared to liposomes or hydrogels alone indicating additional resistance to drug diffusion because of the incorporation of liposomes inside the hydrogels. It is believed that these nanocomposite hydrogels, with controlled degradation properties and sustained release, could serve as potential drug delivery systems for many ocular diseases. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3056–3065, 2014.
Drying and storage effects on poly(ethylene glycol) hydrogel mechanical properties and bioactivity
Authors: Luong P. T. , Browning M. B. , Bixler R. S. , Cosgriff‐Hernandez E. 
Published: October 2013

AbstractHydrogels based on poly(ethylene glycol) (PEG) are increasingly used in biomedical applications because of their ability to control cell‐material interactions by tuning hydrogel physical and biological properties. Evaluation of stability after drying and storage are critical in creating an off‐the‐shelf biomaterial that functions in vivo according to original specifications. However, there has not been a study that systematically investigates the effects of different drying conditions on hydrogel compositional variables. In the first part of this study, PEG‐diacrylate hydrogels underwent common processing procedures (vacuum‐drying, lyophilizing, hydrating then vacuum‐drying), and the effect of this processing on the mechanical properties and swelling ratios was measured. Significant changes in compressive modulus, tensile modulus, and swelling ratio only occurred for select processed hydrogels. No consistent trends were observed after processing for any of the formulations tested. The effect of storage conditions on cell adhesion and spreading on collagen‐ and streptococcal collagen‐like protein (Scl2‐2)‐PEG‐diacrylamide hydrogels was then evaluated to characterize bioactivity retention after storage. Dry storage conditions preserved bioactivity after 6 weeks of storage; whereas, storage in PBS significantly reduced bioactivity. This loss of bioactivity was attributed to ester hydrolysis of the protein linker, acrylate‐PEG‐N‐hydroxysuccinimide. These studies demonstrate that these processing methods and dry storage conditions may be used to prepare bioactive PEG hydrogel scaffolds with recoverable functionality after storage. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3066–3076, 2014.
Synthesis of SiO2 and CaO rich calcium silicate systems via sol‐gel process: Bioactivity, biocompatibility, and drug delivery tests
Authors: Catauro M. , Papale F. , Roviello G. , Ferone C. , Bollino F. , Trifuoggi M. , Aurilio C. 
Published: October 2013

AbstractSilica and calcium silicate amorphous materials, mixed with sodium ampicillin, a broad‐spectrum antibiotic, have been synthesized by sol‐gel method. The amorphous nature of the gels was ascertained by X‐ray diffraction analysis. The bioactivity of the synthesized materials has been put into evidence by the appearance of a crystal of hydroxyapatite on the surface of the samples soaked in a fluid simulating the composition of the human blood plasma, as detected through FTIR measurements and SEM micrographs. The present work refers to a series of in‐vitro biocompatibility tests, which has been performed on silicate and CaO rich calcium silicate gel‐glasses, to study the cell behavior when seeded on 1 cm2 material fragments, introduced into an in‐vitro culture system. 3T3 cell lines have been used and the viability has been evaluated by WST‐8 test. The composition of the adopted glasses can be expressed by the following general formula: x CaO• (1 − x) SiO2 with x = 0.00; 0.30; 0.40; 0.50; 0.60. Subsequently, release kinetics in a simulate body fluid (SBF) has been investigated. The amount of sodium ampicillin released has been detected by UV‐Vis spectroscopy. The release kinetics has appeared to occur in more than one stage. All data have shown that those materials could be used as drug delivery bioactive systems. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3087–3092, 2014.
Evaluation of a bioactive bone‐inducing material consisting of collagen scaffolds and collagen‐binding bone morphogenetic protein 2
Authors: Han Qianqian , Zhang Beibei , Chen Bing , Dai Jianwu , Xu Jianxia , Wang Chunren , Wang Zhaoxu 
Published: October 2013

AbstractBioactive bone‐inducing material (BBIM) is a collagen‐based scaffold composed of demineralized bone matrix and collagen‐binding domain bone morphogenetic protein 2 (BMP‐2). BBIM is regarded as a promising bone‐inducing scaffold to repair bone defects. In this work, we evaluated the biocompatibility and osteogenecity of BBIM. Using enzyme‐linked immunosorbent assay, the level of BMP‐2 on BBIM was detected and considered adequate. Kunming mice were used as the animal model to investigate the acute systemic toxicity, long‐term bone regeneration, ectopic bone formation, and chronic systemic toxicity. Results show that BBIM induced no serious inflammatory reaction or acute and chronic systemic toxicity. Our analyses also demonstrated significant homogeneous ectopic bone formation as well as significantly high numbers of erythrocytes in the BBIM groups in the chronic systemic toxicity study, a phenomenon which may provide indirect proof of the bone regeneration capacity of BBIM, which may be considered as a bioactivity indicator in future studies. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3093–3101, 2014.
Mutant monocyte chemoattractant protein 1 protein attenuates migration of and inflammatory cytokine release by macrophages exposed to orthopedic implant wear particles
Authors: Yao Zhenyu , Keeney Michael , Lin Tzu‐Hua , Pajarinen Jukka , Barcay Katherine , Waters Heather , Egashira Kensuke , Yang Fan , Goodman Stuart 
Published: October 2013

AbstractWear particles generated from total joint replacements can stimulate macrophages to release chemokines, such as monocyte chemoattractant protein 1 (MCP‐1), which is the most important chemokine regulating systemic and local cell trafficking and infiltration of monocyte/macrophages in chronic inflammation. One possible strategy to curtail the adverse events associated with wear particles is to mitigate migration and activation of monocyte/macrophages. The purpose of this study is to modulate the adverse effects of particulate biomaterials and inflammatory stimuli such as endotoxin by interfering with the biological effects of the chemokine MCP‐1. In the current study, the function of MCP‐1 was inhibited by the mutant MCP‐1 protein called 7ND, which blocks its receptor, the C–C chemokine receptor type 2 (CCR2) on macrophages. Addition of 7ND decreased MCP‐1‐induced migration of THP‐1 cells in cell migration experiments in a dose‐dependent manner. Conditioned media from murine macrophages exposed to clinically relevant polymethylmethacrylate (PMMA) particles with/without endotoxin [lipopolysaccharide (LPS)] had a chemotactic effect on human macrophages, which was decreased dramatically by 7ND. 7ND demonstrated no adverse effects on the viability of macrophages, and the capability of mesenchymal stem cells (MSCs) to form bone at the doses tested. Finally, proinflammatory cytokine production was mitigated when macrophages were exposed to PMMA particles with/without LPS in the presence of 7ND. Our studies confirm that the MCP‐1 mutant protein 7ND can decrease macrophage migration and inflammatory cytokine release without adverse effects at the doses tested. Local delivery of 7ND at the implant site may provide a therapeutic strategy to diminish particle‐associated periprosthetic inflammation and osteolysis. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3291–3297, 2014.
The effect of oxidation on the mechanical response and microstructure of porcine aortas
Authors: Stephen Elizabeth A. , Venkatasubramaniam Arundhathi , Good Theresa A. , Timmie Topoleski L. D. 
Published: October 2013

AbstractReactive oxygen species (ROS), a product of many cellular functions, has been implicated in many age‐related pathophysiological processes, including cardiovascular disease. The arterial proteins collagen and elastin may also undergo structural and functional changes due to damage caused by ROS. This study examined the effect of oxidation on the mechanical response of porcine aortas and aorta elastin and the associated changes in structural protein ultrastructure as a step in exploring the role of molecular changes in structural proteins with aging on elastic artery function. We examined the change in mechanical properties of aorta samples after various oxidation times as a first step in understanding how the oxidative environment associated with aging could impact mechanical properties of arterial structural proteins. We used confocal microscopy to visualize how the microstructure of isolated elastin changed with oxidation. We find that short term oxidation of elastin isolated from aortas leads to an increase in material stiffness, but also an increase in the fiber diameter, increase in void space in the matrix, and a decrease in the fiber orientation, possibly due to fiber cross‐linking. The short term effects of oxidation on arterial collagen is more complex, with increase in material stiffness seen in the collagen region of the stress stretch curve at low extents of oxidation, but not at high levels of oxidation. These results may provide insight into the relationship between oxidative damage to tissue associated with aging and disease, structure of the arterial proteins elastin and collagen, and arterial mechanical properties and function. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3255–3262, 2014
Microstructural design of functionally graded coatings composed of suspension plasma sprayed hydroxyapatite and bioactive glass
Authors: Cattini Andrea , Bellucci Devis , Sola Antonella , Pawłowski Lech , Cannillo Valeria 
Published: October 2013

AbstractVarious bioactive glass/hydroxyapatite (HA) functional coatings were designed by the suspension plasma spraying (SPS) technique. Their microstructure, scratch resistance, and apatite‐forming ability in a simulated body fluid (SBF) were compared. The functional coatings design included: (i) composite coating, that is, randomly distributed constituent phases; (ii) duplex coating with glass top layer onto HA layer; and (iii) graded coating with a gradual changing composition starting from pure HA at the interface with the metal substrate up to pure glass on the surface. The SPS was a suitable coating technique to produce all the coating designs. The SBF tests revealed that the presence of a pure glass layer on the working surface significantly improved the reactivity of the duplex and graded coatings, but the duplex coating suffered a relatively low scratch resistance because of residual stresses. The graded coating therefore provided the best compromise between mechanical reliability and apatite‐forming ability in SBF. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 551–560, 2014.
The influence of polymeric component of bioactive glass‐based nanocomposite paste on its rheological behaviors and in vitro responses: Hyaluronic acid versus sodium alginate
Authors: Sohrabi Mehri , Hesaraki Saeed , Kazemzadeh Asghar 
Published: October 2013

AbstractDifferent biocomposite pastes were prepared from a solid phase that was nanoparticles of sol‐gel‐derived bioactive glass and different liquid phases including 3% hyaluronic acid solution, sodium alginate solutions (3% and 10 %) or mixtures of hyaluronic acid and sodium alginate (3% or 10 %) solutions in 50:50 volume ratio. Rheological properties of the pastes were measured in both rotatory and oscillatory modes. The washout behavior and in vitro apatite formation of the pastes were determined by soaking them in simulated body fluid under dynamic situation for 14 days. The proliferation and alkaline phosphatase activity of MG‐63 osteoblastic cells were also determined using extracts of the pastes. All pastes could be easily injected from the standard syringes with different tip diameters. All pastes exhibited visco‐elastic character, but a nonthixotropic paste was obtained using hyaluronic acid in which the loss modulus was higher than the storage modulus. The thixotropy and storage modulus were increasingly improved by adding/using sodium alginate as mixing liquid. Moreover, the pastes in which the liquid phase was sodium alginate or mixture of hyaluronic acid and 10% sodium alginate solution revealed better apatite formation ability and washout resistance than that made of hyaluronic acid alone. No cytotoxicity effects were observed by extracts of the pastes on osteoblasts but better alkaline phosphatase activity was found for the pastes containing hyaluronic acid. Overall, injectable biocomposites can be produced by mixing bioactive glass nanoparticles and sodium alginate/hyaluronic acid polymers. They are potentially useful for hard and even soft tissues treatments. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 561–573, 2014.