RGD肽修饰PEEK表面及其与成骨细胞的相容性

采用丙烯酸等离子体处理聚醚醚酮（PEEK）表面,引入羧基（—COOH）,并利用—COOH将具有生物活性的精氨酸甘氨酸天冬氨酸（RGD）肽化学键合在PEEK的表面;通过X射线光电子能谱仪、水接触角测量仪、表面轮廓仪和万能材料试验机对表面处理前后的PEEK进行表征,并采用MC3T3-E1成骨细胞来评价表面修饰的PEEK的细胞相容性。结果表明,—COOH被成功地引入至PEEK表面,并且RGD肽成功地键合在等离子体羧基化的PEEK表面;丙烯酸等离子体处理和RGD肽的修饰均改善了PEEK表面的亲水性,增加了其表面的粗糙度;等离子体处理和RGD肽的修饰均未影响PEEK的拉伸强度及弯曲强度;等离子体处理和RGD肽的修饰均能改善PEEK表面成骨细胞的黏附、铺展与增殖,但RGD肽修饰的PEEK表面对于促进细胞黏附、铺展与增殖的效果明显优于等离子体羧基化的PEEK表面。     

Preparation of chitosan-sodium alginate/bioactive glass composite cartilage scaffolds with high cell activity and bioactivity

Chitosan-sodium alginate/bioactive glass (CSB) composite cartilage scaffold with outstanding in vitro mineralization property and cytocompatibility is synthesized by freeze drying method. The effect of bioactive glass (BG) addition on the microstructure, porosity, swelling/degradation ratio, in vitro mineralization property and cytocompatibility of CSB scaffold is investigated by the characterization techniques of SEM, XRD, FTIR and BET. Results showed that CSB composite cartilage scaffold had a three-dimensional (3D) porous structure, and both porosity and average pore size met the requirements of cartilage tissue repair. Among, the typical CSB-1.0 had the largest overall pore size and lowest compressive modulus (1.083 ± 0.002 MPa). As the amount of BG increased, pore volume and porosity of CSB scaffolds gradually decreased, and the swelling and degradation ratios gradually reduced. After immersing in SBF for 3 d, cauliflower like hydroxyapatite (HA) was formed on CSB surface, indicating that the scaffold had good in vitro mineralization property. Moreover, the introduction of BG into the composite scaffold can improve the relative cell viability of MC3T3-E1 cells, and CSB-1.0 has the strongest ability to promote the proliferation of cells. Therefore, the as-obtained CSB scaffold can be used as a strong candidate for cartilage tissue engineering scaffold to meet clinical needs.     

氨基修饰聚醚醚酮表面及其成骨细胞相容性

首先采用硼氢化钠将聚醚醚酮(PEEK)表面的羰基还原为羟基,获得羟基化预处理的PEEK,再用3-氨基丙基三乙氧基硅烷与其进行反应,将氨基(—NH2)引入至PEEK表面以改善其细胞相容性。用X射线光电子能谱和力学性能测试对表面化学处理的PEEK进行表征,同时,用MC3T3–E1成骨细胞评价表面氨基修饰的PEEK的细胞相容性。结果表明,硼氢化钠成功地将PEEK表面的羰基还原为羟基,—NH2成功地引入至PEEK表面;表面化学处理前后PEEK的拉伸及弯曲强度未发生明显变化;和未修饰的PEEK表面相比,—NH2修饰的PEEK表面能显著促进成骨细胞的粘附、铺展及增殖。     

Tailoring interfacial interaction through glass fusion in glass/zinc-hydroxyapatite composite coatings on glass-infiltrated zirconia

In the current study, the biocompatibility and mechanical characteristics of glass-infiltrated zirconia were improved via a simple composite coating made of Zn-doped hydroxyapatite (ZnHA) ceramic and a silicate-based glass. During thermal treatment, significant reaction and crystallisation occurred and some of the ZnHA was transformed into β-tricalcium phosphate, calcium oxide phosphate, and calcium zirconium oxide. Moreover, the glass crystallised into a sodium calcium aluminium silicate phase. The mechanical properties were investigated and the results indicated that the amount of glass in the composite and in the glass-infiltrated zirconia layer strongly affected the flexural strength and adhesion of the coating layer. The composite coatings on the glass-infiltrated zirconia displayed better mechanical properties than the pure ZnHA coating due to the newly formed crystalline phases. Murine pre-osteoblastic (MC3T3-E1) cells adhered to and spread well on the composite coating surfaces. The cell viability results revealed that the glass/ZnHA composites demonstrated a superior bioactivity of osteoblast cells compared to uncoated zirconia. These results show that the glass/ZnHA composites on the glass-infiltrated zirconia structure are suitable for use as hard tissue implant coatings due to their morphological and mechanical stability and enhanced bioactivity to pre-osteoblastic cells.     

Enhanced osteogenic activities of polyetheretherketone surface modified by poly(sodium p-styrene sulfonate) via ultraviolet-induced polymerization

Polyetheretherketone (PEEK) is a promising bone and dental tissue engineering material with excellent mechanical properties and biocompatibility, but its biological inertness deficiency limits its clinical applications. In this study, poly(sodium p-styrene sulfonate) (pNaSS) was grafted onto PEEK surface by ultraviolet (UV) induced polymerization to enhance its osteogenic activities. Attenuated total reflectance Fourier transformed Infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM), and contact angle (CA) analysis were carried out to prove the success of grafting polymerization. Toluidine blue O (TBO) colorimetric assay was utilized to quantify the graft amounts of pNaSS. Results showed that the amounts of grafted pNaSS on the PEEK surface could be well-controlled from 0.59 ± 0.07 mmol/cm² to 5.08 ± 0.20 mmol/cm², through adjusting the UV irradiation time and monomer concentration. The hydrophilicity of PEEK surface was increased and the in vitro mineralization ability was promoted with the introduction of pNaSS. Besides, this surface modification method did not influence the intrinsic mechanical properties of PEEK. in vitro biological studies revealed that cell adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells were enhanced with the increase of graft amounts.     

Characterization,in vitro bioactivity and biological studies of sol-gel synthesized SrO substituted 58S bioactive glass

Bioactive glasses (BGs) are considered as a high potential candidate in bone repair and replacement. In the present study, sol–gel derived BGs based on 60% SiO₂-(36%-x) CaO-4%P₂O₅-x SrO (where x = 0, 5 and 10 mol%) quaternary system were synthesized and characterized. The effect of Sr substitutions on bioactivity, proliferation, alkaline phosphatase activity of osteoblast cell line MC3T3-E1 and antibacterial activity were investigated. Dried gels were stabilized at 700 °C to eliminate the nitrates and prevent the crystallization of bioactive glasses. X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy results confirmed the formation of hydroxycarbonate apatite on the BG surfaces. The 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and alkaline phosphate activity results showed that 5% SrO increased both differentiation and proliferation of MC3T3-E1 cells, while 10% SrO resulted in a decrease in bioactivity. Live/Dead and DAPI/Actin staining exhibited viable cell and the morphology of actin fibers and nuclei of MC3T3 cells treated with BG-0 and BG-5. The result of antibacterial test showed that strontium substituted 58S BG exhibited antibacterial effect against methicillin-resistant Staphylococcus aureus bacteria. Taken together, results suggest that 58S BG with 5 mol% SrO is a good candidate for bone tissue engineering with maximum cell proliferation and ALP activity, good bioactivity and high antibacterial efficiency.     

Effect of the micro/nanostructured topography of polyetheretherketone on the behavior of MC3T3-E1 preosteoblasts

Polyetheretherketone (PEEK) is of interest because of its excellent mechanical properties. However, the bioinert nature of PEEK limits its use in clinical applications. In this study, a series of micro/nanostructures combining nano-, submicron-, and microscale on PEEK were fabricated with 0.5, 1, 4, and 6 min of sulfonation time (S1, S2, S3, and S4). Compared to the flat surface on PEEK, the micro/nanostructure of different sizes all significantly promote cell adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. It is shown that micro/nano-porous structures with smaller size and lower roughness of S1 enabled faster cell propagation. The results of alkaline phosphatase staining, alizarin red staining, and quantitative real-time PCR reveal that the osteogenic activity of MC3T3-E1 cells gradually decreases with the increasement of pore size, indicating that the micro/nanostructured topography of S1 generated substantially increased matrix mineralization and bone-like nodule formation, compared to the 3D network surface. This work provides an effective strategy for designing biomaterials with potential clinical applications.     

Effects of fibers and nanoparticles reinforcements on the mechanical and biological properties of hybrid composite polyetheretherketone/short carbon fiber/Nano‐SiO2

Polyetheretherketone (PEEK) composites reinforced with short carbon fibers (SCFs) (20 vol%) and nano‐SiO₂ (1, 1.5, and 2 wt%) particles were prepared by incorporating nanoparticles into PEEK/SCF composites using the internal mixer. In the development of biomaterial, both mechanical and biological characteristics must be considered. Thus, the effects of nanoparticles on the mechanical and biological properties of the PEEK/SCF composites were studied. To evaluate the mechanical properties of this biomaterial, nanoindentation method and tensile test were used. Results showed that by increasing the weight percentage of nano‐SiO₂, the elastic modulus, hardness, and tensile energies were increased. In vitro biological evaluations of the samples were done by performing cytotoxicity (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐iphenyltetrazolium bromide assay) and cell adhesion assays. Cell–material interaction with the surface of the composite was examined by scanning electron microscopy (SEM). In all of the tests, osteoblast cells were used. Results of biological tests showed that the samples are biocompatible and they have no toxicity. Also, Adhered cells presented a normal morphology by SEM and many of the cells were observed to be undergoing cell division. POLYM. COMPOS., 34:1960–1968, 2013. © 2013 Society of Plastics Engineers     

Osteocompatibility characterization of polyacrylonitrile carbon nanofibers containing bioactive glass nanoparticles

A kind of composite carbon nanofibers (CNF) containing bioactive glass (BG) nanoparticles was produced for bone regeneration by a combination of electrospinning and sol–gel techniques. To produce the BG, compounds such as calcium nitrate, triethyl phosphate and tetraethyl orthosilicate were used as precursors and hydrolyzed to form a sol–gel solution, which was then added to a polyacrylonitrile (PAN) solution in N,N-dimethylformamide. The resulting mixture was electrospun to form PAN nanofibers containing the BG precursors. Upon oxidation and carbonization, the PAN nanofibers and BG precursors transformed into continuous CNF embedded with BG nanoparticles (CNF/BG). Through this fabrication technique, several CNF/BG composites were obtained by controlling the feeding ratios of the different precursors giving rise to BG nanoparticles with various compositions (i.e. containing 70–90 mol% of SiO₂ component). In vitro biomineralization in a simulated body fluid and co-culture with MC3T3-E1 osteoblasts studies were performed to evaluate the osteocompatibility of the CNF/BG nanoparticle composites. When compared to pure CNF, the CNF/BG composites showed an improved ability to promote the in vitro formation of apatite and MC3T3-E1 proliferation, which was found to be dependent upon the composition of BG nanoparticles.     

Fabrication and Characterization of Multicomponent Polysaccharide/Nanohydroxyapatite Composite Scaffolds

Carrageenan–hyaluronic acid/nanohydroxyapatite/microcrystalline cellulose composite scaffolds with various amounts of microcrystalline cellulose content (from 0 to 60?wt%) were prepared using freeze-drying method. The results showed highly porous (from 94.0?±?1.09 to 85.0?±?1.05%) composite scaffolds with high water-uptake capacity, average pore size ranging 200–650?µm, and improved mechanical properties (in dry and wet states). Additionally, cytocompatibility of composite scaffolds was evaluated by in vitro culture of osteoblast (MC3T3-E1) cells for 1 and 3 days of incubation and demonstrated good cell adhesion, infiltration, and proliferation. Thus, as-obtained composite scaffolds may have promising application in low-loading bone tissue engineering applications.     

Silicon-Doped Titanium Dioxide Nanotubes Promoted Bone Formation on Titanium Implants

While titanium (Ti) implants have been extensively used in orthopaedic and dental applications, the intrinsic bioinertness of untreated Ti surface usually results in insufficient osseointegration irrespective of the excellent biocompatibility and mechanical properties of it. In this study, we prepared surface modified Ti substrates in which silicon (Si) was doped into the titanium dioxide (TiO₂) nanotubes on Ti surface using plasma immersion ion implantation (PIII) technology. Compared to TiO₂ nanotubes and Ti alone, Si-doped TiO₂ nanotubes significantly enhanced the expression of genes related to osteogenic differentiation, including Col-I, ALP, Runx2, OCN, and OPN, in mouse pre-osteoblastic MC3T3-E1 cells and deposition of mineral matrix. In vivo, the pull-out mechanical tests after two weeks of implantation in rat femur showed that Si-doped TiO₂ nanotubes improved implant fixation strength by 18% and 54% compared to TiO₂-NT and Ti implants, respectively. Together, findings from this study indicate that Si-doped TiO₂ nanotubes promoted the osteogenic differentiation of osteoblastic cells and improved bone-Ti integration. Therefore, they may have considerable potential for the bioactive surface modification of Ti implants.     

Bone Formation Ability and Cell Viability Enhancement of MC3T3-E1 Cells by Ferrostatin-1 a Ferroptosis Inhibitor of Cancer Cells

Recently, ferroptosis has gained scientists’ attention as an iron-related regulated necrosis. However, not many reports have investigated the effect of ferroptosis on bone. Therefore, with the present study, we assessed the effect of ferroptosis inhibition using ferrostatin-1 on the MC3T3-E1 pre-osteoblast cell. Cell images, cell viability, alkaline phosphatase activity test, alizarin red staining, and RUNX2 gene expression using real-time PCR were applied to investigate the effects of ferrostatin and erastin on MC3T3-E1 osteoblast cells. Erastin was used as a well-known ferroptosis inducer reagent. Erastin with different concentrations ranging from 0 to 50 µmol/L was used for inducing cell death. The 25 µmol/L erastin led to controllable partial cell death on osteoblast cells. Ferrostatin-1 with 0 to 40 µmol/L was used for cell doping and cell death inhibition effect. Ferrostatin-1 also displayed a recovery effect on the samples, which had already received the partially artificial cell death by erastin. Cell differentiation, alizarin red staining, and RUNX2 gene expression confirmed the promotion of the bone formation ability effect of ferrostatin-1 on osteoblast cells. The objective of this study was to assess ferrostatin-1’s effect on the MC3T3-E1 osteoblast cell line based on its ferroptosis inhibitory property.     

Effects of thermal history on mechanical behavior of PEEK and its short-fiber composites

The effect of crystallinity differences induced by mold wall temperature and annealing on mechanical behavior is evaluated for poly(etheretherketone) (PEEK) resin and its composites. The systems investigated were neat PEEK, glass fiber (GF) reinforced PEEK, and carbon fiber (CF) reinforced PEEK. Both composite systems were reinforced with 10, 20, and 30 wt% fiber. The degree of crystallinity (X_c) of PEEK was found to increase by processing at higher mold temperatures, by annealing, and by fiber length reductions, which appears to indicate the ability of short fibers to nucleate the crystallization of PEEK under favorable thermal conditions. Improvements in Young's modulus and strength together with ductility reductions are generally obtained as crystallinity increases in both neat PEEK and its composites. The contribution of crystallinity to mechanical behavior is significant only for neat PEEK and PEEK reinforced by 10% fiber. SEM micrographs reveal that this is due to a change in failure mode. When PEEK is reinforced by carbon fibers or by 20–30% glass fibers, a macroscopic brittle mode of failure is observed irrespective of matrix crystallinity, and mechanical behavior is principally determined by the nature and content of the reinforcing fibers.     

特种工程塑料聚芳醚酮

介绍了聚芳醚酮的发展概况、分类及其物化性能;重点对PEEK的性能及应用进行详细阐述;概述了PEEK 的最新研究成果,并指出其今后发展趋势。     

Preliminary Examination of the Thermophysical Bond of Insert-molded Poly (Carbonate)/C Fiber Composites

The adhesive strength of a thermophysical bond between two polymers has been examined using fracture mechanics. Bimaterial composite specimens were constructed by injecting C fiber poly(etheretherketone) (PEEK) into a mold containing one-half of a pre-molded poly(carbonate) (PC) dogbone. The resulting specimens were notched at the interface and tested in tension. Adhesion of the two materials was reasonably good, as demonstrated by fracture surfaces that showed a mixture of PC and C fiber PEEK fragments. Interfacial fracture energy of the composite was approximately 1.5kJ/m².     

Novel poly(3‐hydroxybutyrate) composite films containing bioactive glass nanoparticles for wound healing applications

Bioactive glass is considered an ideal material for haemostasis as it releases Ca²⁺ ions upon hydration, which is required to support thrombosis. In this study the effects of the presence of nanoscaled bioactive glass (n‐BG) in poly(3‐hydroxybutyrate) (P(3HB)) microsphere films on the structural properties, thermal properties and biocompatibility of the films were studied. The n‐BG with a high surface area was also tested for its in vitro haemostatic efficacy and was found to be able to successfully reduce clot detection time. In an effort to study the effect of the roughness induced by the formation of hydroxyapatite on cellular functions such as cell adhesion, cell mobility and cell differentiation, the composite films were immersed in simulated body fluid for periods of 1, 3 and 7 days. From scanning electron microscopy images, the surface of the P(3HB)/n‐BG composite microsphere films appeared fairly uniform and smooth on day 1; however on day 3 and day 7 a rough and uneven surface was observed. The presence of hydroxyapatite on the composite microsphere films on day 3 and day 7 influenced the surface roughness of the films. However, when the P(3HB)/n‐BG composite microsphere films with enhanced surface roughness were tested for biocompatibility, reduced amounts of protein adsorption and cell adhesion were observed. This study thus revealed that there is an optimal surface roughness for the P(3HB) microsphere films for increased cell adhesion, beyond which it could be deleterious for cell adhesion and differentiation. © 2016 Society of Chemical Industry     

Bioactive glass based scaffolds incorporating gelatin/manganese doped mesoporous bioactive glass nanoparticle coating

We investigated the bioactivity and cytocompatibility of 45S5 bioactive glass (BG) based scaffolds coated with a composite layer formed by gelatin and manganese doped mesoporous bioactive glass nanoparticles (Mn-MBGNs). The scaffolds were prepared using the foam replica method, and they were further coated with Mn-MBGNs/gelatin via dip coating. The synthesized scaffolds were characterized in relation to morphology, porosity, mechanical stability, bioactivity and cell biology behavior using osteoblast-like (MG-63) cells. The scaffolds were highly porous with interconnected porosity, and a suitable pore structure was maintained even after the Mn-MBGNs/gelatin coating. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of Mn-MBGNs in the coatings. Moreover, the presence of gelatin was confirmed by Fourier transform infrared spectroscopy (FTIR). The coated scaffolds exhibited in-vitro bioactivity in simulated body fluid comparable to that of uncoated BG scaffolds. Finally, Mn-MBGNs/gelatin coated scaffolds were shown to be non-cytotoxic to MG-63 cells. Hence, the results presented here confirm that the novel Mn containing scaffolds can be considered in the field of biologically active ion releasing scaffolds for bone tissue engineering applications.     

Preliminary Examination of the Thermophysical Bond of Insert-molded Poly (Carbonate)/C Fiber Composites

The adhesive strength of a thermophysical bond between two polymers has been examined using fracture mechanics. Bimaterial composite specimens were constructed by injecting C fiber poly(etheretherketone) (PEEK) into a mold containing one-half of a pre-molded poly(carbonate) (PC) dogbone. The resulting specimens were notched at the interface and tested in tension. Adhesion of the two materials was reasonably good, as demonstrated by fracture surfaces that showed a mixture of PC and C fiber PEEK fragments. Interfacial fracture energy of the composite was approximately 1.5kJ/m².     

Assessment of Cytocompatibility of Bulk Modified Poly-L-lactic Acid Biomaterials

The cytocompatibility and hydrophilicity tests were performed by culturing mouse fibroblastic cells on films of poly-L-lactic acid (PLLA), poly(L-lactic-co-glycolide) (PLGA) and poly(L-lactide-co-glycolide)/ bioactive glass (PLGA/BG) or in the presence of extracts from these polymeric materials. The solvent casting method was used to prepare these films. PLLA films were most hydrophobic and PLGA/BG was least hydrophobic. Compared to the other films, PLLA showed the worst results in cytocompatibility. PLGA also showed favorable results for fibroblastic cells viability. PLGA/BG films also demonstrated improved cell compatibility due to the good biocompatibility of the bioactive glass particles. The results of this study indicate the promising biocompatibility of PLGA/BG as biomaterials in medical field.