MALAT1, a highly conserved long noncoding RNA, is deregulated in several types of cancers. However, its role in esophageal squamous cell carcinoma (ESCC) and its posttranscriptional regulation remain ...poorly understood. In this study we provide first evidences that a posttranscriptional regulation mechanism of MALAT1 by miR-101 and miR-217 exists in ESCC cells. This posttranscriptional silencing of MALAT1 could significantly suppress the proliferation of ESCC cells through the arrest of G2/M cell cycle, which may be due to MALAT1-mediated up-regulation of p21 and p27 expression and the inhibition of B-MYB expression. Moreover, we also found the abilities of migration and invasion of ESCC cells were inhibited after overexpression of miR-101, miR-217, or MALAT1 siRNA. This might be attributed to the deregulation of downstream genes of MALAT1, such as MIA2, HNF4G, ROBO1, CCT4, and CTHRC1. A significant negative correlation exists between miR-101 or miR-217 and MALAT1 in 42 pairs of ESCC tissue samples and adjacent normal tissues. Mice xenograft data also support the tumor suppressor role of both miRNAs in ESCCs.
Background: MALAT1, a highly conserved long non-coding RNA (lncRNA), acts as oncogene in multiple human cancers.
Results: miR-101 and miR-217 can silence MALAT1 expression and then inhibit esophageal cancer proliferation, migration and invasion.
Conclusion: Tumor suppressor miR-101 and miR-217 can negatively regulate MALAT1 expression.
Significance: These data provide a new mechanism for MALAT1 regulation.
Polylactic acid/Hydroxyapatite (PLA/HA) composite was widely studied and applied in the field of biomaterials for its good processability, bioactivity, and mechanical properties. In addition to ...traditional preparation methods, additive manufacturing has also been adopted to prepare PLA/HA composites with customized geometries. This work combined the comprehensive optimized PLLA (L-polylactic acid)/nano-HA (nHA) composite with the low-cost and stable Fused deposition modeling (FDM) technology to successfully prepare PLLA/nHA porous bone repair scaffolds. The results showed that PLLA/nHA composite ink satisfied the smoothness of printing, and the accuracy also met the requirements of personalized bone repair application. The high loaded nHA scaffold had suitable compressive strength was significantly higher than those of pure HA ceramic scaffold and cancellous bone. Besides, in vitro bone-like apatite formation on the surface in the degradation process and in vivo evaluations further verified its good osteogenic property. Compared with other complex and cutting-edge 3D printing technologies, this study provides a low-cost, stable, simple and fast way to realize personalized printing of bone repair scaffolds, which is undoubtedly conductive to the improvement and rapid deployment of personalized biomaterials in clinical applications.
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•Comprehensive optimized PLLA/nano-hydroxyapatite composite was made successfully for bone repair scaffold printing.•Bone-like apatite can form on the scaffold surface in vitro degradation experiments just in PBS, indicating the high bioactivity of scaffold.•The high loaded nano- hydroxyapatite scaffold has suitable compressive strength and good osteogenic property.•This study provides a low-cost, stable, simple and fast way to realize personalized printing of bone repair scaffolds.
The Ti6Al4V alloy is one of the most commonly used in orthopedic surgery. Mechanical property of implant contributes important biological functions for load-bearing bone tissue reconstruction. There ...is a significant need for design and fabrication of porous scaffold with customized mechanical properties for bone tissue engineering. In this paper, bionic design and fabrication of porous implants were studied by using finite element analysis (FEA) and 3D printing techniques. Novel porous architectures were built up with diamond lattice pore structure arraying units. With finite element analysis, the structure weak points under pressure were simulated so that the mechanical properties of the implants were optimized. Porous implants with different porosities and mechanical properties were precisely fabricated by selected laser melting (SLM), one of powder bed fusion additive manufacturing techniques. The biocompatibility and repair effect were studied by in vivo experiments. Animal results indicated that the damaged load-bearing bones were well reconstructed. New generated bones embedded and fitted into the designed porous implants. The optimized design and precisely manufactured implants are conducive to bone tissue repair and reconstruction.
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•Scaffolds showed biomimetic structure design and customized mechanical properties.•Scaffolds with 66.1%–79.5% porosity were biomimetic designed by using diamond lattice pore units array formation.•Scaffolds within a wide range of compressive strength from 36 to 140 MPa were successfully fabricated.•Animal results indicated that the damaged load-bearing bones were well reconstructed.
Bioceramics, because of its excellent biocompatible and mechanical properties, has always been considered as the most promising materials for hard tissue repair. It is well know that an appropriate ...cellular response to bioceramics surfaces is essential for tissue regeneration and integration. As the in vivo implants, the implanted bioceramics are immediately coated with proteins from blood and body fluids, and it is through this coated layer that cells sense and respond to foreign implants. Hence, the adsorption of proteins is critical within the sequence of biological activities. However, the biological mechanisms of the interactions of bioceramics and proteins are still not well understood. In this review, we will recapitulate the recent studies on the bioceramic–protein interactions.
Bone defect and osteoporosis are common in clinic which are seriously harmful for public health. Bionic bone tissue engineering scaffolds are very important for bone tissue repair and reconstruction. ...In this study, different bionic bone tissue engineering scaffolds were constructed by computer-aided design and fabricated by selected laser melting. Novel porous structures were designed by using parameterization modeling. The accurate models with key characteristics such as porosity and the mechanical property of scaffolds were studied. Compared with the designed model, the error of the selective laser melting (SLM) printed scaffold porosity was less than 2.73%. The mechanical properties of the prepared scaffold can be calculated by finite element analysis of 3D models, and the mechanical properties of the 3D printed samples were consistent with the model design. Through the design, manufacture, characterization and evaluation of the scaffold porous structures, the parametric modeling of porous titanium bone tissue engineering scaffold with good mechanical and biological properties was realized. Optimized design and precisely manufactured implants are very important for bone tissue repair and reconstruction.
The design and fabrication of porous scaffold remains a major challenge in bone tissue engineering. Hierarchical microporous and macroporous structures in scaffold contribute different biological ...functions to tissue regeneration. This study introduced an integrated manufacturing method to fabricate hierarchical porous polymer scaffolds. Firstly, polylactic acid (PLA) scaffolds with 100–800μm macropores were fabricated by applying fused deposition modeling (FDM) techniques. Then, 1–10μm micropores were generated in scaffolds through gas foaming. This combined technique avoids the disadvantages of pure 3DP or gas foaming technology and elicits positive cooperative effects to fabricate hierarchical porous scaffolds. The design of porosity in scaffold could offer innovative opportunities to control cell performance within 3D microenvironments.
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•Hierarchical macro/microporous polymer scaffold was fabricated.•Scaffolds with 100–800μm macropores were initially fabricated by using FDM technique.•Scaffolds with 1–10μm micropores were then fabricated by using gas foaming.•The integrated manufacturing method can fabricate grotesque and large scaffolds for bone tissue engineering application.
In the process of bone regeneration, new bone formation is largely affected by physico-chemical cues in the surrounding microenvironment. Tissue cells reside in a complex scaffold physiological ...microenvironment. The scaffold should provide certain circumstance full of structural cues to enhance multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and subsequent new bone formation. This article reviewed advances in fabrication technology that enable the creation of biomaterials with well-defined pore structure and surface topography, which can be sensed by host tissue cells (esp., stem cells) and subsequently determine cell fates during differentiation. Three important cues, including scaffold pore structure (i.e., porosity and pore size), grain size, and surface topography were studied. These findings improve our understanding of how the mechanism scaffold microenvironmental cues guide bone tissue regeneration.
Zirconium oxide (ZrO
) is the general material in dental area, with natural color, high toughness and strength. Recent years, small blocks of ZrO
such as micro/nano powders have been studied and ...developed widely. Nano scale ZrO
, which show simproved mechanical characteristics and superior biocompatibility, are usually incorporated into different applications used in dentistry and tissue engineering. This review provides an overview of nano-ZrO
materials and its applications in dentistry. The synthesis of nano-ZrO
powders were mainly prepared by coprecipitation, hydrothermal method and sol-gel method. Then different applications of nano-ZrO
biomaterials in dental ceramics, implants, radio pacifying agents, basement and tissue engineering fields were briefly introduced.
Coal ash (CA) is not only one of the most solid wastes from combustion, easily resulting in a series of concerns, but it is also an artificial deposit with considerable metals, such as iron and rare ...earth. The variation in the coal ash characteristics due to the origins, combustion process, and even storage environment has been hindering the metal utilization from coal ash. In this study, three ash sample from lab muffle, circulating fluidized bed (CFB), and pulverized coal (PC) furnace was derived for the discrepancy study from the combustion furnace, including properties, iron, and rare earth recovery. The origins of the coal feed samples have more of an effect on their properties than combustion furnaces. Magnetic separation is suitable for coal ash from PC because of the magnetite product, and the iron content is 58% in the Mag-1 fraction, with a yield of 3%. The particles in CA from CFB appear irregular and fragmental, while those from PC appear spherical with a smooth surface. The results of sequential chemical extraction and observation both indicated that the aluminosilicate phase plays an essential role in rare earth occurrences. Rare earth in CA from muffling and CFB is facilely leached, with a recovery of approximately 50%, which is higher than that from PC ash. This paper aims to offer a reference to easily understand the difference in metal recovery from coal ash.
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