Co-reporter:Yancong Zhang;Yongliang Li;Ruirui Shi;Siqi Zhang
Stem Cell Research & Therapy 2017 Volume 8( Issue 1) pp:141
Publication Date(Web):08 June 2017
DOI:10.1186/s13287-017-0583-5
A number of studies have shown that tooth-like structures can be regenerated using induced pluripotent stem cells and mouse embryonic stem (mES) cells. However, few studies have reported the regeneration of tooth–periodontium complex structures, which are more suitable for clinical tooth transplantation. We established an optimized approach to induce high-odontogenic potential dental epithelium derived from mES cells by temporally controlling bone morphogenic protein 4 (BMP4) function and regenerated tooth–periodontium complex structures in vivo.First, immunofluorescence and quantitative reverse transcription-polymerase chain reaction were used to identify the watershed of skin and the oral ectoderm. LDN193189 was then used to inhibit the BMP4 receptor around the watershed, followed by the addition of exogenous BMP4 to promote BMP4 function. The generated dental epithelium was confirmed by western blot analysis and immunofluorescence. The generated epithelium was ultimately combined with embryonic day 14.5 mouse mesenchyme and transplanted into the renal capsules of nude mice. After 4 weeks, the tooth–periodontium complex structure was examined by micro-computed tomography (CT) and hematoxylin and eosin (H&E) staining.Our study found that the turning point of oral ectoderm differentiation occurred around day 3 after the embryoid body was transferred to a common culture plate. Ameloblastin-positive dental epithelial cells were detected following the temporal regulation of BMP4. Tooth–periodontium complex structures, which included teeth, a periodontal membrane, and alveolar bone, were formed when this epithelium was combined with mouse dental mesenchyme and transplanted into the renal capsules of nude mice. Micro-CT and H&E staining revealed that the generated tooth–periodontium complex structures shared a similar histological structure with normal mouse teeth.An optimized induction method was established to promote the differentiation of mES cells into dental epithelium by temporally controlling the function of BMP4. A novel tooth–periodontium complex structure was generated using the epithelium.
Co-reporter:Yan Li;Zuyuan Luo;Xiao Xu;Yongliang Li;Siqi Zhang;Ping Zhou;Yi Sui;Minjie Wu;En Luo
Journal of Materials Chemistry B 2017 vol. 5(Issue 34) pp:7153-7163
Publication Date(Web):2017/08/30
DOI:10.1039/C7TB01732D
Several bone diseases, including arthritis, fracture and osteoporosis, have a pathophysiologically important inflammatory component. Sustained inflammation can result in delayed bone healing. Therefore, to promote bone repair, it is important to inhibit inflammatory bone erosion and suppress pro-inflammatory mediators. In this study, aspirin significantly enhanced immunomodulation and osteogenic differentiation in human mesenchymal stem cells (hMSCs). Additionally, an osteogenic BFP-1 peptide-decorated substrate (PS-PEP) enhanced osteogenic differentiation of aspirin-treated hMSCs compared to a pristine substrate. Alkaline phosphatase assay, quantitative real-time polymerase chain reaction, immunostaining and Alizarin Red S staining revealed that aspirin-treated hMSCs cultured on PS-PEP exhibited enhanced osteogenesis compared with untreated cells. Thus, we report here that the anti-inflammatory and osteogenic effects of aspirin promote the activity and osteogenesis of hMSCs. The combination of aspirin and an osteogenic BFP-1 peptide-decorated substrate suppresses the production of pro-inflammatory mediators and promotes osteogenic differentiation of hMSCs; therefore, this novel strategy has potential for application in cell therapy and bone tissue engineering.
Co-reporter:Anxiu Xu, Liwei Zhou, Yi Deng, Xianshen Chen, Xiaoling Xiong, Feng Deng and Shicheng Wei
Journal of Materials Chemistry A 2016 vol. 4(Issue 10) pp:1878-1890
Publication Date(Web):10 Feb 2016
DOI:10.1039/C5TB02782A
Carbon fiber-reinforced polyetheretherketone (CFRPEEK) possesses biomechanical properties such as elastic modulus similar to human bones and is becoming a dominant alternative to replace the traditional metallic implants. The defective osseointegration and bacterial infection risk of CFRPEEK, however, impede its clinical adoption. In the current study, a newly-developed carbon fiber-reinforced polyetheretherketone/nanohydroxyapatite (CFRPEEK/n-HA) ternary biocomposite was functionalized by covalently grafting carboxymethyl chitosan (CMC) followed by the decoration of a bone-forming peptide (BFP) assisted via the polydopamine tag strategy. Antibacterial test with Staphylococcus aureus (S. aureus) indicated that the CMC and peptide-conjugated substrates (pep-CMC-CFRPEEK/n-HA) significantly suppressed bacterial adhesion. In vitro cell attachment/growth, spreading assay, alkaline phosphatase activity, real-time PCR analysis, osteogenesis-related protein expression and calcium mineral deposition all disclosed greatly accelerated adhesion, proliferation and osteo-differentiation of human mesenchymal stem cells (hMSCs) on the pep-CMC-CFRPEEK/n-HA biocomposite due to the additive effect of the CMC polysaccharide and the small osteoinductive peptide. More importantly, in vivo evaluation of the beagle tibia model by means of micro-CT, histological analysis, SEM observation and fluorescent labeling confirmed the remarkably boosted bioactivity and osteointegration. The CFRPEEK/n-HA ternary composite with the dual functions of bacterial adhesion reduction and osteointegration promotion holds great potential as a bioactive implant material in orthopedic/dental applications based on this scheme.
Co-reporter:Zuyuan Luo, Yue Yang, Yi Deng, Yuhua Sun, Hongtao Yang, Shicheng Wei
Colloids and Surfaces B: Biointerfaces 2016 Volume 143() pp:243-251
Publication Date(Web):1 July 2016
DOI:10.1016/j.colsurfb.2016.03.047
•An innovative 3D p-PAS are prepared without carbodiimide chemistry treatment.•The p-PAS induce the proliferation and aggregation of osteoblasts.•The regeneration of bone defects in vivo is promoted by p-PAS.•Combination of PAS and peptide presents a potential for tissue engineering.Good bioactivity and osteogenesis of three-dimensional porous alginate scaffolds (PAS) are critical for bone tissue engineering. In this work, alginate and bone-forming peptide-1 (BFP-1), derived from bone morphogenetic protein-7 (BMP-7), have been combined together (without carbodiimide chemistry treatment) to develop peptide-incorporated PAS (p-PAS) for promoting bone repairing ability. The mechanical properties and SEM images show no difference between pure PAS and p-PAS. The release kinetics of the labeled peptide with 6-carboxy tetramethyl rhodamine from the PAS matrix suggests that the peptide is released in a relatively sustained manner. In the cell experiment, p-PAS show higher cell adhesion, spreading, proliferation and alkaline phosphatase (ALP) activity than the pristine PAS group, indicating that the BFP-1 released from p-PAS could significantly promote the aggregation and differentiation of osteoblasts, especially at 10 μg/mL of trapped peptide concentration (p-PAS-10). Furthermore, p-PAS-10 was implanted into Beagle calvarial defects and bone regeneration was analyzed after 4 weeks. New bone formation was assessed by calcein and Masson’s trichrome staining. The data reveal that p-PAS group exhibits significantly enhanced oseto-regenerative capability in vivo. The peptide-modified PAS with promoted bioactivity and osteogenic differentiation in vitro as well as bone formation ability in vivo could be promising tissue engineering materials for repairing and regeneration of bone defects.
Co-reporter:Yanjie Bai, Yi Deng, Yunfei Zheng, Yongliang Li, Ranran Zhang, Yalin Lv, Qiang Zhao, Shicheng Wei
Materials Science and Engineering: C 2016 Volume 59() pp:565-576
Publication Date(Web):1 February 2016
DOI:10.1016/j.msec.2015.10.062
•A β-type Ti–45Nb alloy was developed with low Young's modulus close to human bone.•Ti–Nb alloy had superior corrosion resistance to pure Ti in different solutions.•Ti–Nb alloy displayed good cytocompatibility and in vivo bone tissue compatibility.•Ti–Nb alloy could be suitable for orthopedic/dental application based on the study.β-Type titanium alloys with a low elastic modulus are a potential strategy to enhance bone remodeling and to mitigate the concern over the risks of osteanabrosis and bone resorption caused by stress shielding, when used to substitute irreversibly impaired hard tissue. Hence, in this study, a Ti–45Nb alloy with low Young's modulus and high strength was developed, and microstructure, mechanical properties, corrosion behaviors, cytocompatibility and in vivo osteo-compatibility of the alloy were systematically investigated for the first time. The results of mechanical tests showed that Young's modulus of the Ti–Nb alloy was reduced to about 64.3 GPa (close to human cortical bone) accompanied with higher tensile strength and hardness compared with those of pure Ti. Importantly, the Ti–Nb alloy exhibited superior corrosion resistance to Ti in different solutions including SBF, MAS and FAAS (MAS containing NaF) media. In addition, the Ti–Nb alloy produced no deleterious effect to L929 and MG-63 cells, and cells performed excellent cell attachment onto Ti–Nb surface, indicating a good in vitro cytocompatibility. In vivo evaluations indicated that Ti–Nb had comparable bone tissue compatibility to Ti determined from micro-CT and histological evaluations. The Ti–Nb alloy with an elasticity close to human bone, thus, could be suitable for orthopedic/dental applications.
Co-reporter:Jinshuai Chen, Zhiwu Yu, Peizhi Zhu, Junfeng Wang, Zhehong Gan, Jie Wei, Yinghui Zhao and Shicheng Wei
Journal of Materials Chemistry A 2015 vol. 3(Issue 1) pp:34-38
Publication Date(Web):05 Nov 2014
DOI:10.1039/C4TB01561D
For the first time we observed well-resolved Ca(I) and Ca(II) signal changes in fluorohydroxyapatites with different fluorine contents by solid state NMR. The experiment results show that fluorine ions perturb the chemical environment of Ca(II) ions and OH− ions more than phosphorus tetrahedra and Ca(I) ions.
Co-reporter:Mengke Wang, Yi Deng, Ping Zhou, Zuyuan Luo, Qiuhong Li, Bingwu Xie, Xiaohong Zhang, Tong Chen, Duanqing Pei, Zhihui Tang, and Shicheng Wei
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 8) pp:4560
Publication Date(Web):February 11, 2015
DOI:10.1021/acsami.5b00188
Human pluripotent stem cells (hPSCs) are a promising cell source with pluripotency and capacity to differentiate into all human somatic cell types. Designing simple and safe biomaterials with an innate ability to induce osteoblastic lineage from hPSCs is desirable to realize their clinical adoption in bone regenerative medicine. To address the issue, here we developed a fully defined synthetic peptides-decorated two-dimensional (2D) microenvironment via polydopamine (pDA) chemistry and subsequent carboxymethyl chitosan (CMC) grafting to enhance the culture and osteogenic potential of hPSCs in vitro. The hPSCs including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) were successfully cultured on the peptides-decorated surface without Matrigel and ECM protein coating and underwent promoted osteogenic differentiation in vitro, determined from the alkaline phosphate (ALP) activity, gene expression, and protein production as well as calcium deposit amount. It was found that directed osteogenic differentiation of hPSCs was achieved through a peptides-decorated niche. This chemically defined and safe 2D microenvironment, which facilitates proliferation and osteo-differentiation of hPSCs, not only helps to accelerate the translational perspectives of hPSCs but also provides tissue-specific functions such as directing stem cell differentiation commitment, having great potential in bone tissue engineering and opening new avenues for bone regenerative medicine.Keywords: carboxymethyl chitosan; human pluripotent stem cells; osteogenic differentiation; peptide; polydopamine
Co-reporter:Zuyuan Luo, Yi Deng, Ranran Zhang, Mengke Wang, Yanjie Bai, Qiang Zhao, Yalin Lyu, Jie Wei, Shicheng Wei
Colloids and Surfaces B: Biointerfaces 2015 Volume 131() pp:73-82
Publication Date(Web):1 July 2015
DOI:10.1016/j.colsurfb.2015.04.043
•An innovative p-MSNs are synthesized to slow-release peptide osteogenic factor.•The p-MSNs induce the adhesion and proliferation of MG-63 cells.•The osteo-differentiation of the p-MSNs is enhanced after decoration of peptide.•Combination of MSNs and growth factors presents a potential for tissue engineering.Combination of mesoporous silica materials and bioactive factors is a promising niche-mimetic solution as a hybrid bone substitution for bone tissue engineering. In this work, we have synthesized biocompatible silica-based nanoparticles with abundant mesoporous structure, and incorporated bone-forming peptide (BFP) derived from bone morphogenetic protein-7 (BMP-7) into the mesoporous silica nanoparticles (MSNs) to obtain a slow-release system for osteogenic factor delivery. The chemical characterization demonstrates that the small osteogenic peptide is encapsulated in the mesoporous successfully, and the nitrogen adsorption–desorption isotherms suggest that the peptide encapsulation has no influence on mesoporous structure of MSNs. In the cell experiment, the peptide-laden MSNs (p-MSNs) show higher MG-63 cell proliferation, spreading and alkaline phosphatase (ALP) activity than the bare MSNs, indicating good in vitro cytocompatibility. Simultaneously, the osteogenesis-related proteins expression and calcium mineral deposition disclose enhanced osteo-differentiation of human mesenchymal stem cells (hMSCs) under the stimulation of the p-MSNs, confirming that BFP released from MSNs could significantly promote the osteogenic differentiation of hMSCs, especially at 500 μg/mL of p-MSNs concentration. The peptide-modified MSNs with better bioactivity and osteogenic differentiation make it a potential candidate as bioactive material for bone repairing, bone regeneration, and bio-implant coating applications.
Co-reporter:Yi Deng, Ping Zhou, Xiaochen Liu, Lixin Wang, Xiaoling Xiong, Zhihui Tang, Jie Wei, Shicheng Wei
Colloids and Surfaces B: Biointerfaces 2015 Volume 136() pp:64-73
Publication Date(Web):1 December 2015
DOI:10.1016/j.colsurfb.2015.09.001
As FDA-approved implantable material, polyetheretherketone (PEEK) is becoming a prime candidate to replace traditional surgical metallic implants made of titanium (Ti) and its alloys, since it has a lower elastic modulus than Ti. The bioinertness and defective osteointegration of PEEK, however, limit its clinical adoption as load-bearing dental/orthopedic material. The present work aimed at developing a PEEK bioactive ternary composite, polyetheretherketone/nano-hydroxyapatite/carbon fiber (PEEK/n-HA/CF), and evaluating it as a potential bone-repairing material by assessment of growth and differentiation of osteoblast-like MG63 cells and by estimation of osteointegration in vivo. Our results indicated that the adhesion, proliferation and osteogenic differentiation of cells, as well as the mechanical properties were greatly promoted for the PEEK/n-HA/CF biocomposite compared with pure PEEK matrix. More importantly, the ternary composite implant boosted in vivo bioactivity and osseointegration in canine tooth defect model. Thus, the PEEK/n-HA/CF ternary biocomposite with enhanced mechanics and biological performances hold great potential as bioactive implant material in dental and orthopedic applications.
Co-reporter:Yi Deng, Xiaohong Zhang, Yinghui Zhao, Shangshang Liang, Anxiu Xu, Xiang Gao, Feng Deng, Jing Fang, Shicheng Wei
Carbohydrate Polymers 2014 Volume 101() pp:36-39
Publication Date(Web):30 January 2014
DOI:10.1016/j.carbpol.2013.09.030
•The peptide-decorated PVA/HA polysaccharide nanofiber was successfully fabricated.•The PVA/HA nanofibers supported the adhesion and proliferation of hiPSCs.•Cell differentiation was enhanced by the peptide-decorated PVA/HA nanofibers.•The nanofibers provide well-defined conditions for hiPSCs growth and differentiation.Realization of the full potential of human induced pluripotent stem cells (hiPSCs) in clinical applications requires development of well-defined conditions for their growth and differentiation. A novel fully defined polyvinyl alcohol/hyaluronan (PVA/HA) polysaccharide nanofiber was developed for hiPSCs culture in commercially available xeno-free, chemically defined medium. Vitronectin peptide (VP) was immobilized to PVA/HA nanofibers through NHS/EDC chemistry. The hiPSCs successfully grew and proliferated on the VP-decorated PVA/HA nanofibers, similar to those on Matrigel™. Such well-defined, xeno-free and safe nanofiber substrate that supports culture of hiPSCs will not only help to accelerate the translational perspectives of hiPSCs, but also provide a platform to investigate the cell–nanofiber interaction mechanisms that regulate stem cell proliferation and differentiation.
Co-reporter:Lixin Wang, Shu He, Xiaomian Wu, Shanshan Liang, Zhonglin Mu, Jie Wei, Feng Deng, Yi Deng, Shicheng Wei
Biomaterials 2014 35(25) pp: 6758-6775
Publication Date(Web):
DOI:10.1016/j.biomaterials.2014.04.085
Co-reporter:Minzhi Zhao, Qingsong Wang, Wenjia Lai, Xuyang Zhao, Hongyan Shen, Feilong Nie, Yufeng Zheng, Shicheng Wei and Jianguo Ji
Journal of Materials Chemistry A 2013 vol. 1(Issue 14) pp:1926-1938
Publication Date(Web):06 Feb 2013
DOI:10.1039/C3TB00266G
Nanostructured titanium prepared by the equal-channel angular pressing route (ECAPed Ti) has shown great promise as an implant material over conventional pure titanium. The aim of this report is to investigate its biological properties, surface performance, and comprehensive biological effects at a molecular level when in contact with cells. Protein expression changes of human osteoblast-like MG-63 in response to polished ECAPed Ti had been profiled by employing stable isotope labelling with amino acids in cell culture (SILAC), using cpTi as control after the same polishing process. It was found that ubiquitin proteasome related processes were predominantly enriched in the over-expressed proteins. Superoxide dismutase 2 (SOD2) was apparently up-regulated on the ECAPed Ti surface, which could have contributed to the increase in SOD activity and the decrease in the reactive oxygen species (ROS) level. These expression changes have relationships with protein degradation, bone formation and resistance to oxidative injury, and they suggest that ECAPed Ti has the potential to further promote osteoblast differentiation. On the other hand, the down-regulated proteins exhibited resistance to platelet adhesion on the ECAPed Ti surface. This study reveals the differential expression of proteins in human osteoblasts induced by nanostructured titanium substrates for the first time.
Co-reporter:Y. Deng, X. Zhang, X. Zhao, Q. Li, Z. Ye, Z. Li, Y. Liu, Y. Zhou, H. Ma, G. Pan, D. Pei, J. Fang, S. Wei
Acta Biomaterialia 2013 Volume 9(Issue 11) pp:8840-8850
Publication Date(Web):November 2013
DOI:10.1016/j.actbio.2013.07.017
Abstract
Realization of the full potential of human induced pluripotent stem cells (hiPSC) in clinical applications requires the development of well-defined culture conditions for their long-term growth and directed differentiation. This paper describes a novel fully defined synthetic peptide-decorated substrate that supports self-renewal of hiPSC in commercially available xeno-free, chemically defined medium. The Au surface was deposited by a poly(OEGMA-co-HEMA) film, using the surface-initiated polymerization method (SIP) with the further step of carboxylation. The hiPSC generated from umbilical cord mesenchymal cells were successfully cultured for 10 passages on the peptide-tethered poly(OEGMA-co-HEMA) brushes for the first time. Cells maintained their characteristic morphology, proliferation and expressed high levels of markers of pluripotency, similar to the cells cultured on Matrigel™. Moreover, the cell adhesion could be tuned by the pattern and peptide concentration on the substrate. This well-defined, xeno-free and safe substrate, which supports long-term proliferation and self-renewal of hiPSC, will not only help to accelerate the translational perspectives of hiPSC, but also provide a platform to elucidate the underlying molecular mechanisms that regulate stem cell proliferation and differentiation via SIP technology.
Co-reporter:F. L. Nie;Y. F. Zheng;S.C. Wei;D. S. Wang;Z. T. Yu;G. K. Salimgareeva;A. V. Polyakov;R. Z. Valiev
Journal of Biomedical Materials Research Part A 2013 Volume 101A( Issue 6) pp:1694-1707
Publication Date(Web):
DOI:10.1002/jbm.a.34472
Abstract
Bulk nanocrystalline Ti bars (Grade 4, ϕ4 × 3000 mm3) were massively fabricated by equal channel angular pressing (ECAP) via follow-up conform scheme with the microcrystalline CP Ti as raw material. Homogeneous nanostructured crystals with the average grain size of 250 nm were identified for the ECAPed Ti, with extremely high tensile/fatigue strength (around 1240/620 MPa) and adorable elongation (more than 5%). Pronounced formation of bonelike apatite for the nanocrystalline Ti group after 14 days static immersion in simulated body fluids (SBF) reveals the prospective in vitro bioactive capability of fast calcification, whereas an estimated 17% increment in protein adsorption represents good bioaffinity of nanocrystalline Ti. The documentation onto the whole life circle of osteoblast cell lines (MG63) revealed the strong interactions and superior cellular functionalization when they are co-incubated with bulk nanocrystalline Ti sample. Moreover, thread-structured specimens were designed and implanted into the tibia of Beagles dogs till 12 weeks to study the in vivo responses between bone and metallic implant made of bulk nanocrystalline Ti, with the microcrystalline Ti as control. For the implanted nanostructured Ti group, neoformed bone around the implants underwent the whole-stage transformation proceeding from originally osteons or immature woven bone to mature lamellar bone (skeletonic trabecular), even with the remodeling being finished till 12 weeks. The phenomenal osseointegration of direct implant-bone contact can be revealed from the group of the ECAPed Ti without fibrous tissue encapsulation in the gap between the implant and autogenous bone. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Co-reporter:Xiangmei Zhang;Ling Xu;Maolin Zhai;Jiuqiang Li
Journal of Biomedical Materials Research Part A 2013 Volume 101A( Issue 8) pp:2191-2201
Publication Date(Web):
DOI:10.1002/jbm.a.34525
Abstract
Collagen hydrogels were prepared via radiation crosslinking. The simulated physiological environmental effects related to their biomedical applications on the volume phase transition of collagen hydrogel were studied, that is stimuli response to ions, temperature, and pH. The deswelling behavior of collagen hydrogel depends on the salt concentration, temperature, pH, and the hydrogel preparation procedure. Meanwhile, hydrogel structure related to the volume phase transition was investigated by FTIR, fluorescence spectrum, and HR-MAS NMR. Deswelling in salt solution caused little change on collagen conformation, and a denser network led to more significant tyrosine-derived fluorescence quenching. Hydrogen bonding between hydrated water and collagen polypeptide chain was dissociated and the activity of hydrophobic side chain increased, inducing a higher extent of contraction with the increasing of salt concentration. Moreover, salt solution treatments weakened the electrostatic interactions, side chains interactions, and hydrogen bonding of collagen hydrogel, which reduced the thermal stability of collagen hydrogel. Comparing with cell-free collagen hydrogel contraction, fibroblasts did not aggravate contraction of collagen hydrogel significantly. This study elucidated the deswelling mechanism of radiation crosslinked collagen hydrogel in simulated physiological environment and provides strategies for controlling the stimuli response of collagen hydrogel in biomedical application. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Co-reporter:Yi Deng, Yuhua Sun, Xiaofang Chen, Peizhi Zhu, Shicheng Wei
Materials Science and Engineering: C 2013 Volume 33(Issue 5) pp:2905-2913
Publication Date(Web):1 July 2013
DOI:10.1016/j.msec.2013.03.016
•Heparin was used as a template to synthesize needle-shaped nano-apatite.•Changing the pH value and concentration led to different properties of apatite.•Apatite prepared by heparin was more favorable to the osteogenic differentiation.•Possible synthesis mechanism of apatite templated by heparin was described.Biomimetic synthesis of carbonated apatites with good biocompatibility is a promising strategy for the broadening application of apatites for bone tissue engineering. Most researchers were interested in collagen or gelatin-based templates for synthesis of apatite minerals. Inspired by recent findings about the important role of polysaccharides in bone biomineralization, here we reported that heparin, a mucopolysaccharide, was used to synthesize carbonated apatites in vitro. The results indicated that the Ca/P ratio, carbon content, crystallinity and morphology of the apatites varied depending on the heparin concentration and the initial pH value. The morphology of apatite changed from flake-shaped to needle-shaped, and the degree of crystallinity decreased with the increasing of heparin concentration. Biocompatibility of the apatites was tested by proliferation and alkaline phosphatase activity of MC3T3-E1 cells. The results suggested that carbonated apatites synthesized in the presence of heparin were more favorable to the proliferation and differentiation of MC3T3-E1 cells compared with traditional method. In summary, the heparin concentration and the initial pH value play a key role in the chemical constitution and morphology, as well as biological properties of apatites. These biocompatible nano-apatite crystals hold great potential to be applied as bioactive materials for bone tissue engineering.
Co-reporter:Yuhua Sun, Yi Deng, Ziyou Ye, Shanshan Liang, Zhihui Tang, Shicheng Wei
Colloids and Surfaces B: Biointerfaces 2013 Volume 111() pp:107-116
Publication Date(Web):1 November 2013
DOI:10.1016/j.colsurfb.2013.05.037
•An innovative bone forming peptide decorated nano-HA was developed via pDA coating.•The peptide-conjugated HA induced the adhesion and proliferation of MG-63 cells.•The osteogenic differentiation of the peptide-conjugated HA was enhanced.•This research establishes a safe, effective and stable strategy for modifying HA.To be better used as implant materials in bone graft substitutes, bioactivity and osteogenesis of nano-hydroxyapatite (nano-HA) need to be further enhanced. Inspired by adhesive proteins in mussels, here we developed a novel bone forming peptide decorated nano-HA material. In this study, nano-HA was coated by one-step pH-induced polymerization of dopamine, and then the peptide was grafted onto polydopamine (pDA) coated nano-HA (HA-pDA) through catechol chemistry. Our results demonstrated that the peptide-conjugated nano-HA crystals could induce the adhesion and proliferation of MG-63 cells. Moreover, the highly alkaline phosphatase activity of the functionalized nano-HA indicated that the grafted peptide could maintain its biological activity after immobilization onto the surface of HA-pDA, especially at the concentration of 100 μg/mL. These modified nano-HA crystals with better bioactivity and osteogenic differentiation hold great potential to be applied as bioactive materials in bone repairing, bone regeneration and bio-implant coating applications.
Co-reporter:Qiuhong Li, Ming Li, Peizhi Zhu and Shicheng Wei
Journal of Materials Chemistry A 2012 vol. 22(Issue 38) pp:20257-20265
Publication Date(Web):22 Aug 2012
DOI:10.1039/C2JM33624C
Being a biocompatible and bioactive material, hyaluronic acid has great potential as a template to regulate the mineralization of hydroxyapatite (HA) nanocrystals in vitro. Our present study investigates the effects of sodium hyaluronate (SH) concentrations and initial pH values on the chemical composition, morphology and biological properties of hydroxyapatite (HA) crystals prepared by the wet chemical approach. All purified products were studied by Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), X-ray photo-electronic spectroscopy (XPS), and transmission electron microscopy (TEM). This is the first time that bioactive carbonated apatites were synthesized using SH as a template. Biocompatibility of such apatites was gauged by cell vitality and alkaline phosphatase activity of MG-63 cells. The results suggested that carbonated apatites synthesized in the presence of SH were more favorable to the proliferation and differentiation of MG-63 cells compared to conventional apatites. In our study, we also found that SH temporarily stabilizes amorphous calcium phosphate (ACP) at the early stage of crystallization. The results imply that the initial pH value and the concentration of SH play a key role in affecting calcium vacancies, carbonate content and morphology of apatite crystals, as well as their effects on the proliferation and osteogenic differentiation of MG-63 cells. These synthesized carbonate-containing apatites are potentially attractive candidates for tissue engineering applications.
Co-reporter:Xiao Zou, Minzhi Zhao, Hongyan Shen, Xuyang Zhao, Yuanpeng Tong, Qingsong Wang, Shicheng Wei, Jianguo Ji
Journal of Proteomics 2012 Volume 75(Issue 17) pp:5516-5522
Publication Date(Web):18 September 2012
DOI:10.1016/j.jprot.2012.06.028
Isobaric tagging techniques such as iTRAQ and TMT are widely used in quantitative proteomics and especially useful for samples that demand in vitro labeling. Due to diversity in choices of MS acquisition approaches, identification algorithms, and relative abundance deduction strategies, researchers are faced with a plethora of possibilities when it comes to data analysis. However, the lack of generic and flexible software tool often makes it cumbersome for researchers to perform the analysis entirely as desired. In this paper, we present MilQuant, mzXML-based isobaric labeling quantitator, a pipeline of freely available programs that supports native acquisition files produced by all mass spectrometer types and collection approaches currently used in isobaric tagging based MS data collection. Moreover, aside from effective normalization and abundance ratio deduction algorithms, MilQuant exports various intermediate results along each step of the pipeline, making it easy for researchers to customize the analysis. The functionality of MilQuant was demonstrated by four distinct datasets from different laboratories. The compatibility and extendibility of MilQuant makes it a generic and flexible tool that can serve as a full solution to data analysis of isobaric tagging-based quantitation.Highlights► MilQuant is a free software for analyzing isobaric tagging based quantitation data. ► MilQuant is a highly flexible and customizable pipeline. ► MilQuant supports various MS types and collection approaches. ► Both intensity- and ratio-based relative abundance deduction are offered. ► The capacity of MilQuant is illustrated by analysis of four datasets.
Co-reporter:Minzhi Zhao, Mingrui An, Qingsong Wang, Xiaochen Liu, Wenjia Lai, Xuyang Zhao, Shicheng Wei, Jianguo Ji
Journal of Proteomics 2012 Volume 75(Issue 12) pp:3560-3573
Publication Date(Web):27 June 2012
DOI:10.1016/j.jprot.2012.03.033
Commercially pure titanium (cpTi) and polyetheretherketone (PEEK) are widely used surface-modified implant materials in orthopedics and dental therapeutics. However, there still has not been comprehensive biocompatibility evaluation of them at molecular level. By employing stable isotope labeling with amino acids in cell culture (SILAC), we profiled the dynamic protein expression changes in human osteoblast-like MG-63 cells cultured on cpTi and PEEK, respectively. About 2000 proteins were quantified and 400 proteins showed substantial alterations in expression levels upon each material treatment. Notably, the extent of alterations diminished as the contact prolonged, which suggested adaptive response to the bioinert materials. Similar patterns of expression changes were observed for both cpTi and PEEK. The representative pathways reflected the regulation of biosynthesis, metabolism and cell adhesion in the adaptive process. In addition, PEEK showed stronger inhibition on mRNA processing, which explained the lower proliferation rate of the cells cultured on PEEK. Our results indicated that the widely used bioinert materials cpTi and PEEK could individually induce a cooperative response involving a wide panel of proteins and pathways. This study has established a basis for better understanding the biocompatibility of surface-modified implant biomaterials at molecular level.Highlights► Titanium and polyetheretherketone induces similar response in osteoblast proteome. ► Overlapped protein function includes biosynthesis, metabolism and cell adhesion. ► Dynamic expression reflects the adaptive process of cells to biomaterial treatment. ► Stimulation response and negative regulation are main effects of bioinert materials. ► Polyetheretherketone causing worse proliferation was related to mRNA processing.
Co-reporter:Xiangmei Zhang;Ling Xu;Xin Huang;Maolin Zhai
Journal of Biomedical Materials Research Part A 2012 Volume 100A( Issue 11) pp:2960-2969
Publication Date(Web):
DOI:10.1002/jbm.a.34243
Abstract
Under γ-irradiation, concentrated collagen solutions yielded collagen hydrogels and liquid products. The molecular structure of collagen hydrogels and the source of the liquid products were studied. Furthermore, preliminary biological properties of the hydrogels were investigated. The results revealed that crosslinking occurred to form collagen hydrogel and the crosslinking density increased with the increasing of the absorbed dose, and the collagen hydrogels showed enhanced mechanical properties. Meanwhile, collagen underwent radiation degradation and water was squeezed out from hydrogel by contraction of hydrogel, yielding liquid products. Collagen hydrogels induced by γ-irradiation maintained the backbone structure of collagen, and tyrosine partially involved in crosslinking. The irradiated collagen hydrogels have higher denatured temperature, can promote fibroblasts proliferation, and their degradation rate in vivo depended on the absorbed dose. The comprehensive results suggested that the collagen hydrogels prepared by radiation crosslinking preserved the triple helical conformation, possessed improved thermal stability and mechanical properties, excellent biocompatibility, which is expected to favor its application as biomaterials. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:2960–2969, 2012.
Co-reporter:Yinghui Zhao, Ying Zhou, Xiaomian Wu, Lu Wang, Ling Xu, Shicheng Wei
Applied Surface Science 2012 Volume 258(Issue 22) pp:8867-8873
Publication Date(Web):1 September 2012
DOI:10.1016/j.apsusc.2012.05.106
Abstract
A facile method to prepare silver nanoparticles (AgNPs) containing nanofibers via electrospinning has been demonstrated. AgNPs were in situ synthesized in poly (vinyl alcohol) (PVA)/carboxymethyl-chitosan (CM-chitosan) blend aqueous solution before electrospinning. UV–vis spectra, viscosity and conductivity of the electrospinning solution were measured to investigate their effects on the electrospinning procedure. The morphology of AgNPs/PVA/CM-chitosan nanofibers was observed by Field Emission Scanning Electron Microscopy. The formation and morphology of AgNPs were investigated by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. The resulted nanofibers have smooth surface and uniform diameters ranging from 295 to 343 nm. The diameters of AgNPs mainly distributed in the range of 4–14 nm, and the electrostatic interaction between AgNPs and fibers was observed. Finally, in vitro Ag release from the nanofibers was measured and the antibacterial behavior of the nanofibers against Escherichia coli was studied by bacterial growth inhibition halos and bactericidal kinetic testing. The AgNPs/PVA/CM-chitosan nanofibers possessed certain antibacterial ability, which makes them capable for antibacterial biomaterials.
Co-reporter:Ying Zhou, Ling Xu, Xiangmei Zhang, Yinghui Zhao, Shicheng Wei, Maolin Zhai
Materials Science and Engineering: C 2012 Volume 32(Issue 4) pp:994-1000
Publication Date(Web):1 May 2012
DOI:10.1016/j.msec.2012.02.029
A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and β-tricalcium phosphate (β-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of β-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of β-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that β-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of β-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/β-TCP composite scaffolds as candidate of bone tissue engineering material.Highlights► Radiation induced a crosslinked scaffold with interconnected porous structure. ► Ultrasonic time of 20 min led to homogenerously distribution of β-TCP. ► Increasing amount of β-TCP would restrict the swelling properties. ► Proper fraction of β-TCP will promote the mechanical properties of the scaffolds. ► Hybrid of β-TCP promoted the bone regeneration of the mandibles of beagle dogs.
Co-reporter:Xixue Hu, Hong Shen, Kegang Shuai, Enwei Zhang, Yanjie Bai, Yan Cheng, Xiaoling Xiong, Shenguo Wang, Jing Fang, Shicheng Wei
Applied Surface Science 2011 Volume 257(Issue 6) pp:1813-1823
Publication Date(Web):1 January 2011
DOI:10.1016/j.apsusc.2010.08.082
Abstract
Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.
Co-reporter:Xiaoshuai Ren, Yuanzi Wu, Yan Cheng, Hongwei Ma, and Shicheng Wei
Langmuir 2011 Volume 27(Issue 19) pp:12069-12073
Publication Date(Web):September 2, 2011
DOI:10.1021/la202438u
To be better used as medical implants in orthopedic and dental clinical applications, titanium and titanium-based alloys need to be capable of inducing osteogenesis. Here we describe a method that allows the facile decoration of titanium surfaces to impart an osteogenesis capacity. A Ti surface was first deposited on a poly(OEGMA-r-HEMA) film using surface-initiated atom-transfer radical polymerization (SI-ATRP) with the further step of carboxylation. The modified surfaces were resistant to cell adhesion. Fibronectin (FN) and recombinant human bone morphogenetic protein-2 (rhBMP-2) were further immobilized onto p(OEGMA-r-HEMA) matrices. Our results demonstrate that the FN- and rhBMP-2-conjugated polymer surfaces could induce the adhesion of MC3T3 cells on Ti surfaces. Moreover, the protein-tethered surface exhibited enhanced cell differentiation in terms of alkaline phosphatase activity compared to that of the pristine Ti surface at similar cell proliferation rates. This research establishes a simple modification method of Ti surfaces via Ti-thiolate self-assembled monolayers (SAMs) and SI-ATRP and identifies a dual-functional Ti surface that combines antifouling and osseointegration promotion.
Co-reporter:Chao Yang, Ling Xu, Ying Zhou, Xiangmei Zhang, Xin Huang, Min Wang, Ye Han, Maolin Zhai, Shicheng Wei, Jiuqiang Li
Carbohydrate Polymers 2010 Volume 82(Issue 4) pp:1297-1305
Publication Date(Web):11 November 2010
DOI:10.1016/j.carbpol.2010.07.013
A series of hydrogels were fabricated from an aqueous solution of gelatin and carboxymethyl chitosan (CM-chitosan) by radiation-induced-crosslinking at ambient temperature. Several physicochemical and biological properties of the hydrogels were investigated to evaluate their potential as wound healing materials. By increasing the CM-chitosan content in the hybrid hydrogels, their swelling ability increased significantly, while the compressive modulus decreased. The miscibility between gelatin and CM-chitosan molecules led to a semi-interpenetrate network after crosslinking. Observed by SEM, scaffolds with a homogeneous interconnected pore structure were obtained after lyophilizing the hydrogels. The enzyme degradation rate of the hydrogels was controlled by adjusting the procedure, which could be matched to the healing rate of the wound. Furthermore, the gelatin/CM-chitosan hydrogels promoted cell attachment and rapid growth of fibroblasts on the material. Due to the high water absorption capacity, a similar compressive modulus with soft tissue, controllable biodegradation, and excellent biocompatibility, the gelatin/CM-chitosan hybrid hydrogels have potential as skin scaffolds and wound healing materials.
Co-reporter:Jing Wu, Yuan An, Hai Pu, Yue Shan, Xiaoqing Ren, Mingrui An, Qingsong Wang, Shicheng Wei, Jianguo Ji
Analytical Biochemistry 2010 Volume 398(Issue 1) pp:34-44
Publication Date(Web):1 March 2010
DOI:10.1016/j.ab.2009.10.047
Serum low-molecular-weight proteins (LMWPs, molecular weight <30 kDa) are closely related to the body physiological and pathological situations, whereas many difficulties are encountered when enriching and fractionating them. Using C18 absorbent (100 Å) enrichment and fractionation under urea/dithiothreitol (DTT) denatured environment followed by 60% acetonitrile (ACN) elution, serum LMWPs could be enriched more than 100-fold and were evaluated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), two-dimensional gel electrophoresis (2-DE), and isotope-coded affinity tag (ICAT) labeling quantification. Proteins existing in human serum at low nanograms/milliliter (ng/ml) levels, such as myeloid-related proteins (MRPs), could be identified directly from 2-DE coupled with matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI–TOF/TOF MS) and LTQ–Orbitrap MS. Sixteen proteins were confidentially identified and quantified using ICAT labeling and liquid chromatography–tandem mass spectrometry (LC–MS/MS). By virtue of its easy operation and high reproducibility to process large quantity complex serum samples, this method has potential uses in enriching LMWPs either in serum or in cell and tissue samples.
Co-reporter:Xixue Hu, Hong Shen, Yan Cheng, Xiaoling Xiong, Shenguo Wang, Jing Fang, Shicheng Wei
Surface and Coatings Technology 2010 205(7) pp: 2000-2006
Publication Date(Web):
DOI:10.1016/j.surfcoat.2010.08.088
Co-reporter:Ping Zhou, Fujian Wu, Tiancheng Zhou, Xiujuan Cai, Siqi Zhang, Xiaohong Zhang, Qiuhong Li, Yongliang Li, Yunfei Zheng, Mengke Wang, Feng Lan, Guangjin Pan, Duanqing Pei, Shicheng Wei
Biomaterials (May 2016) Volume 87() pp:1-17
Publication Date(Web):May 2016
DOI:10.1016/j.biomaterials.2016.02.012
Human pluripotent stem cells (hPSCs) possess great value in the aspect of cellular therapies due to its self-renewal and potential to differentiate into all somatic cell types. A few defined synthetic surfaces such as polymers and adhesive biological materials conjugated substrata were established for the self-renewal of hPSCs. However, none of them was effective in the generation of human induced pluripotent stem cells (hiPSCs) and long-term maintenance of multiple hPSCs, and most of them required complicated manufacturing processes. Polydopamine has good biocompatibility, is able to form a stable film on nearly all solid substrates surface, and can immobilize adhesive biomolecules. In this manuscript, a polydopamine-mediated surface was developed, which not only supported the reprogramming of human somatic cells into hiPSCs under defined conditions, but also sustained the growth of hiPSCs on diverse substrates. Moreover, the proliferation and pluripotency of hPSCs cultured on the surface were comparable to Matrigel for more than 20 passages. Besides, hPSCs were able to differentiate to cardiomyocytes and neural cells on the surface. This polydopamine-based synthetic surface represents a chemically-defined surface extensively applicable both for fundamental research and cell therapies of hPSCs.
Co-reporter:Ping Zhou, Fujian Wu, Tiancheng Zhou, Xiujuan Cai, Siqi Zhang, Xiaohong Zhang, Qiuhong Li, Yongliang Li, Yunfei Zheng, Mengke Wang, Feng Lan, Guangjin Pan, Duanqing Pei, Shicheng Wei
Biomaterials (May 2016) Volume 87() pp:1-17
Publication Date(Web):May 2016
DOI:10.1016/j.biomaterials.2016.02.012
Co-reporter:Ying Zhou, Yinghui Zhao, Lu Wang, Ling Xu, Maolin Zhai, Shicheng Wei
Radiation Physics and Chemistry (May 2012) Volume 81(Issue 5) pp:553-560
Publication Date(Web):1 May 2012
DOI:10.1016/j.radphyschem.2012.01.014
A series of antibacterial hydrogels were fabricated from an aqueous solution of AgNO3, gelatin and carboxymethyl chitosan (CM-chitosan) by radiation-induced reduction and crosslinking at ambient temperature. The nanosilver particles were in situ synthesized accompanying with the formation of gelatin/CM-chitosan hydrogel. Transmission Electron Microscope and UV–vis analysis have verified the formation and homogeneous distribution of nanosilver particles in the hydrogel matrix. The nanosilver/gelatin/CM-chitosan hydrogels possessed interconnected porous structure, had a compressive modulus of 44 to 56 kPa, and could absorb 62 to 108 times of deionized water to its dry weight. Furthermore, the hydrogels were found to have sound antibacterial effect on Escherichia coli (E. coli), and their antibacterial ability could be significantly enhanced by the increasing of AgNO3 content. The comprehensive results of this study suggest that nanosilver/gelatin/CM-chitosan hydrogels have potential as an antibacterial wound dressing.Highlights► Nanosilver/gelatin/CM-chitosan hydrogel was synthesized by radiation crosslinking. ► Nanosilver particles distributed homogeneously in the hydrogel. ► The size of nanosilver increased with the increase of AgNO3 concentration. ► The nanosilver/gelatin/CM-chitosan hydrogel has antibacterial ability.
Co-reporter:Jinshuai Chen, Zhiwu Yu, Peizhi Zhu, Junfeng Wang, Zhehong Gan, Jie Wei, Yinghui Zhao and Shicheng Wei
Journal of Materials Chemistry A 2015 - vol. 3(Issue 1) pp:NaN38-38
Publication Date(Web):2014/11/05
DOI:10.1039/C4TB01561D
For the first time we observed well-resolved Ca(I) and Ca(II) signal changes in fluorohydroxyapatites with different fluorine contents by solid state NMR. The experiment results show that fluorine ions perturb the chemical environment of Ca(II) ions and OH− ions more than phosphorus tetrahedra and Ca(I) ions.
Co-reporter:Minzhi Zhao, Qingsong Wang, Wenjia Lai, Xuyang Zhao, Hongyan Shen, Feilong Nie, Yufeng Zheng, Shicheng Wei and Jianguo Ji
Journal of Materials Chemistry A 2013 - vol. 1(Issue 14) pp:NaN1938-1938
Publication Date(Web):2013/02/06
DOI:10.1039/C3TB00266G
Nanostructured titanium prepared by the equal-channel angular pressing route (ECAPed Ti) has shown great promise as an implant material over conventional pure titanium. The aim of this report is to investigate its biological properties, surface performance, and comprehensive biological effects at a molecular level when in contact with cells. Protein expression changes of human osteoblast-like MG-63 in response to polished ECAPed Ti had been profiled by employing stable isotope labelling with amino acids in cell culture (SILAC), using cpTi as control after the same polishing process. It was found that ubiquitin proteasome related processes were predominantly enriched in the over-expressed proteins. Superoxide dismutase 2 (SOD2) was apparently up-regulated on the ECAPed Ti surface, which could have contributed to the increase in SOD activity and the decrease in the reactive oxygen species (ROS) level. These expression changes have relationships with protein degradation, bone formation and resistance to oxidative injury, and they suggest that ECAPed Ti has the potential to further promote osteoblast differentiation. On the other hand, the down-regulated proteins exhibited resistance to platelet adhesion on the ECAPed Ti surface. This study reveals the differential expression of proteins in human osteoblasts induced by nanostructured titanium substrates for the first time.
Co-reporter:Anxiu Xu, Liwei Zhou, Yi Deng, Xianshen Chen, Xiaoling Xiong, Feng Deng and Shicheng Wei
Journal of Materials Chemistry A 2016 - vol. 4(Issue 10) pp:NaN1890-1890
Publication Date(Web):2016/02/10
DOI:10.1039/C5TB02782A
Carbon fiber-reinforced polyetheretherketone (CFRPEEK) possesses biomechanical properties such as elastic modulus similar to human bones and is becoming a dominant alternative to replace the traditional metallic implants. The defective osseointegration and bacterial infection risk of CFRPEEK, however, impede its clinical adoption. In the current study, a newly-developed carbon fiber-reinforced polyetheretherketone/nanohydroxyapatite (CFRPEEK/n-HA) ternary biocomposite was functionalized by covalently grafting carboxymethyl chitosan (CMC) followed by the decoration of a bone-forming peptide (BFP) assisted via the polydopamine tag strategy. Antibacterial test with Staphylococcus aureus (S. aureus) indicated that the CMC and peptide-conjugated substrates (pep-CMC-CFRPEEK/n-HA) significantly suppressed bacterial adhesion. In vitro cell attachment/growth, spreading assay, alkaline phosphatase activity, real-time PCR analysis, osteogenesis-related protein expression and calcium mineral deposition all disclosed greatly accelerated adhesion, proliferation and osteo-differentiation of human mesenchymal stem cells (hMSCs) on the pep-CMC-CFRPEEK/n-HA biocomposite due to the additive effect of the CMC polysaccharide and the small osteoinductive peptide. More importantly, in vivo evaluation of the beagle tibia model by means of micro-CT, histological analysis, SEM observation and fluorescent labeling confirmed the remarkably boosted bioactivity and osteointegration. The CFRPEEK/n-HA ternary composite with the dual functions of bacterial adhesion reduction and osteointegration promotion holds great potential as a bioactive implant material in orthopedic/dental applications based on this scheme.
Co-reporter:Qiuhong Li, Ming Li, Peizhi Zhu and Shicheng Wei
Journal of Materials Chemistry A 2012 - vol. 22(Issue 38) pp:NaN20265-20265
Publication Date(Web):2012/08/22
DOI:10.1039/C2JM33624C
Being a biocompatible and bioactive material, hyaluronic acid has great potential as a template to regulate the mineralization of hydroxyapatite (HA) nanocrystals in vitro. Our present study investigates the effects of sodium hyaluronate (SH) concentrations and initial pH values on the chemical composition, morphology and biological properties of hydroxyapatite (HA) crystals prepared by the wet chemical approach. All purified products were studied by Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), X-ray photo-electronic spectroscopy (XPS), and transmission electron microscopy (TEM). This is the first time that bioactive carbonated apatites were synthesized using SH as a template. Biocompatibility of such apatites was gauged by cell vitality and alkaline phosphatase activity of MG-63 cells. The results suggested that carbonated apatites synthesized in the presence of SH were more favorable to the proliferation and differentiation of MG-63 cells compared to conventional apatites. In our study, we also found that SH temporarily stabilizes amorphous calcium phosphate (ACP) at the early stage of crystallization. The results imply that the initial pH value and the concentration of SH play a key role in affecting calcium vacancies, carbonate content and morphology of apatite crystals, as well as their effects on the proliferation and osteogenic differentiation of MG-63 cells. These synthesized carbonate-containing apatites are potentially attractive candidates for tissue engineering applications.
