Chen Shaoming
,
Gao Manman
,
Zhou Zhiyu
,
Liang Jiabi
,
Gong Ming
,
Dai Xuejun
,
Liang Tangzhao
,
Ye Jiacheng
,
Wu Gang
,
Zou Lijin
,
Wang Yingjun
,
Zou Xuenong
材料科学技术（英文）
doi:10.1016/j.jmst.2016.08.001
Although cartilage tissue engineering has been developed for decades, it is still unclear whether angiogenesis was the accompaniment of chondrogenesis in cartilage regeneration. This study aimed to explore the process of anti-angiogenesis during cartilage regenerative progress in cartilage repair extracellular matrix (ECM) materials under Hypoxia. C3H10T1/2 cell line, seeded as pellet or in ECM materials, was added with chondrogenic medium or DMEM medium for 21 days under hypoxia or normoxia environment. Genes and miRNAs related with chondrogenesis and angiogenesis were detected by RT-qPCR technique on Days 7, 14, and 21. Dual-luciferase report system was used to explore the regulating roles of miRNAs on angiogenesis. Results showed that the chondrogenic medium promotes chondrogenesis both in pellet and ECM materials culture. HIF1α was up-regulated under hypoxia compared with normoxia (P?<?0.05). Meanwhile, hypoxia enhanced chondrogenesis. miR-140-5p exhibited higher expression while miR-146b exhibited lower expression. The chondrogenic phenotype was more stabilized in the ECM materials in chondrogenic medium than DMEM medium, with lower VEGFα expression even under hypoxia. Dual-luciferase report assays demonstrated that miR-140-5p directly targets VEGFα by binding its 3′-UTR. Taken together, chondrogenic cytokines, ECM materials and hypoxia synergistically promoted chondrogenesis and inhibited angiogenesis. miR-140-5p played an important role in this process.
关键词:
Biomaterials
,
Bio-adaptation
,
Hypoxia
,
Chondrogenesis
,
Angiogenesis
,
miRNAs
Hou Jie
,
Gao Huichang
,
Wang Yingjun
,
Cheng Delin
,
Cao Xiaodong
材料科学技术（英文）
doi:10.1016/j.jmst.2016.08.013
Modifying substrates through mineralization is a popular way to improve the osteogenic performance. Screening of the best mineralization characteristics on specific substrates for stem cells is meaningful but not fully studied. In this paper, poly(lactic-co-glycolic acid)/hydroxyapatite (PLGA/HA, PH) microsphere scaffolds with superficial pores were fabricated by a low-temperature fusion method. After the mineralization in the 5× stimulated body fluid (SBF) for 0, 7, 12 and 24?h, four mineralized scaffolds (MPH-0, MPH-7, MPH-12 and MPH-24) with different apatite topographies were obtained. It was found that the surface of MPH-7 was evenly decorated with abundant micro-pores, MPH-12 with dense and plain apatite layer, and MPH-24 with small spherical bumps. The responses of mouse bone mesenchymal stem cells (mBMSCs) to the four scaffolds were further studied. The results showed that MPH-7 and MPH-24 had more obvious effects on mBMSCs attachment, proliferation and differentiation than MPH-0 and MPH-12. This work indicated that to obtain the maximum improvement, the mineralization characteristics had to be carefully chosen. This was noteworthy in the chemical modification of surfaces to form the functionalized scaffolds for bone repair.
关键词:
Microsphere scaffold
,
Mineralization
,
Topography
,
Cell behavior
Wang Yingjun
材料科学技术（英文）
doi:10.1016/j.jmst.2016.08.002
Biocompatibility is the basic requirement of biomaterials for tissue repair. However, the present concept of biocompatibility has a certain limitation in explaining the phenomena involved in biomaterial-based tissue repair. New materials, in particular those for tissue engineering and regeneration, have been developed with common characteristics, i.e. they participate deeply into important chemical and biological processes in the human body and the interaction between the biomaterials and tissues is far more complex. Understanding the interplay between these biomaterials and tissues is vital for their development and functionalization. Herein, we suggest the concept of bioadaptability of biomaterials. This concept describes the three most important aspects that can determine the performance of biomaterials in tissue repair: 1) the adaptability of the micro-environment created by biomaterials to the native micro-environment in situ; 2) the adaptability of the mechanical properties of biomaterials to the native tissue; 3) the adaptability of the degradation properties of biomaterials to the new tissue formation. The concept of bioadaptability emphasizes both the material's characteristics and biological aspects within a certain micro-environment and molecular mechanism. It may provide new inspiration to uncover the interaction mechanism of biomaterials and tissues, to foster the new ideas of functionalization of biomaterials and to investigate the fundamental issues during the tissue repair process by biomaterials. Furthermore, designing biomaterials with such bioadaptability would open a new door for repairing and regenerating organs or tissues. In this review, we summarized the works in recent years on the bioadaptability of biomaterials for tissue repair applications.
关键词:
Bioadaptability
,
Biomaterials
,
Functional design
,
Tissue repair
Pan Ting
,
Song Wenjing
,
Cao Xiaodong
,
Wang Yingjun
材料科学技术（英文）
doi:10.1016/j.jmst.2016.01.007
Gelatin/Alginate hydrogels were engineered for bioplotting in tissue engineering. One major drawback of hydrogel scaffolds is the lack of adequate mechanical properties. In this study, using a bioplotter, we constructed the scaffolds with different pore architectures by deposition of gelatin/alginate hydrogels layer-by-layer. The scaffolds with different crosslinking degree were obtained by post-crosslinking methods. Their physicochemical properties, as well as cell viability, were assessed. Different crosslinking methods had little influence on scaffold architecture, porosity, pore size and distribution. By contrast, the water absorption ability, degradation rate and mechanical properties of the scaffolds were dramatically affected by treatment with various concentrations of crosslinking agent (glutaraldehyde). The crosslinking process using glutaraldehyde markedly improved the stability and mechanical strength of the hydrogel scaffolds. Besides the post-processing methods, the pore architecture can also evidently affect the mechanical properties of the scaffolds. The crosslinked gelatin/alginate scaffolds showed a good potential to encapsulate cells or drugs.
关键词:
Bioplotting
,
Tissue engineering
,
Scaffolds
,
Gelatin
,
Alginate
Gao Huichang
,
Cao Xiaodong
,
Dong Hua
,
Fu Xiaoling
,
Wang Yingjun
材料科学技术（英文）
doi:10.1016/j.jmst.2016.01.011
In this paper, we fabricated three kinds of 3D microgrooves with different depth on biocompatible poly(lactic-co-glycolic acid) (PLGA) substrate via combination of soft-lithography and melt-casting methods, and investigated in detail their influence on C2C12 cell behaviors. It is found that cell proliferation, migration, alignment, spatial distribution, F-actin protein expression and gene expression are all remarkably distinct on these microgrooved samples and the smooth control PLGA substrate. The associated underlying mechanisms were further analyzed and discussed using real-time living cell monitoring, confocal laser scanning microscopy and gene microarray. Our preliminary results suggested that 3D microstructure could affect cell behaviors in a much more extensive manner than what we had understood before.
关键词:
Cell behaviors
,
3D microgroove
,
Poly(lactic-co-glycolic acid)
,
Cytoskeleton
,
Gene microarray
,
Real-time living cell monitoring
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
材料科学技术（英文）
The effect of interstitial hydrogen on the cohesion of the Al Sigma=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.
关键词:
hydrogen;grain boundary;Al-Mg alloys;pseudopotentials;1st-principles
Xiaoguang LIU
,
Xiaowei WANG
材料科学技术（英文）
The effect of interstitial hydrogen on the cohesion of the Al ∑=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.
关键词:
Hydrogen
,
null
,
null
