18 research outputs found
Porous Collagen Scaffold Reinforced with Surfaced Activated PLLA Nanoparticles
Porous collagen scaffold is integrated with surface activated PLLA nanoparticles fabricated by lyophilizing and crosslinking via EDC treatment. In order to prepare surface-modified PLLA nanoparticles, PLLA was firstly grafted with poly (acrylic acid) (PAA) through surface-initiated polymerization of acrylic acid. Nanoparticles of average diameter 316ānm and zeta potential ā39.88āmV were obtained from the such-treated PLLA by dialysis method. Porous collagen scaffold were fabricated by mixing PLLA nanoparticles with collagen solution, freeze drying, and crosslinking with EDC. SEM observation revealed that nanoparticles were homogeneously dispersed in collagen matrix, forming interconnected porous structure with pore size ranging from 150 to 200āĪ¼m, irrespective of the amount of nanoparticles. The porosity of the scaffolds kept almost unchanged with the increment of the nanoparticles, whereas the mechanical property was obviously improved, and the degradation was effectively retarded. In vitro L929 mouse fibroblast cells seeding and culture studies revealed that cells infiltrated into the scaffolds and were distributed homogeneously. Compared with the pure collagen sponge, the number of cells in hybrid scaffolds greatly increased with the increment of incorporated nanoparticles. These results manifested that the surface-activated PLLA nanoparticles effectively reinforced the porous collagen scaffold and promoted the cells penetrating into the scaffold, and proliferation
CerealsDB 3.0:Expansion of resources and data integration
BACKGROUND: The increase in human populations around the world has put pressure on resources, and as a consequence food security has become an important challenge for the 21st century. Wheat (Triticum aestivum) is one of the most important crops in human and livestock diets, and the development of wheat varieties that produce higher yields, combined with increased resistance to pests and resilience to changes in climate, has meant that wheat breeding has become an important focus of scientific research. In an attempt to facilitate these improvements in wheat, plant breeders have employed molecular tools to help them identify genes for important agronomic traits that can be bred into new varieties. Modern molecular techniques have ensured that the rapid and inexpensive characterisation of SNP markers and their validation with modern genotyping methods has produced a valuable resource that can be used in marker assisted selection. CerealsDB was created as a means of quickly disseminating this information to breeders and researchers around the globe. DESCRIPTION: CerealsDB version 3.0 is an online resource that contains a wide range of genomic datasets for wheat that will assist plant breeders and scientists to select the most appropriate markers for use in marker assisted selection. CerealsDB includes a database which currently contains in excess of a million putative varietal SNPs, of which several hundreds of thousands have been experimentally validated. In addition, CerealsDB also contains new data on functional SNPs predicted to have a major effect on protein function and we have constructed a web service to encourage data integration and high-throughput programmatic access. CONCLUSION: CerealsDB is an open access website that hosts information on SNPs that are considered useful for both plant breeders and research scientists. The recent inclusion of web services designed to federate genomic data resources allows the information on CerealsDB to be more fully integrated with the WheatIS network and other biological databases. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12859-016-1139-x) contains supplementary material, which is available to authorized users
A model for facilitating translational research and development in China: Call for establishing a Hong Kong Branch of the Chinese National Engineering Research Centre for Biomaterials
With significant improvements in living standards in China and the aging population that accompanies these improvements, the market demand for high-quality orthopaedic biomaterials for clinical applications is tremendous and growing rapidly. There are major efforts to promote cooperation between different scientific institutes with complementary strengths for the further development of the biomaterial industry in China to achieve the technological level of developed countries. An excellent example is that the Ministry of Science and Technology of the People's Republic of China (MOST; Beijing, China) established the Chinese National Engineering Research Centres (CNERCs), which serve as a major initiative in driving basic and applied technological research and development (R&D) in mainland China. To create a win-win situation with Hong Kong, the MOST and the Hong Kong Innovation and Technology Commission are jointly establishing the Hong Kong Branch of the CNERCs. Through an amicable arrangement, the Chinese University of Hong Kong (CUHK; Shatin, Hong Kong) and the Chinese National Engineering Research Centre for Biomaterials (i.e., Main Centre) in Chengdu, People's Republic of China have decided to apply to establish the Hong Kong Branch of the CNERC for Biomaterials at the CUHK. The effort in establishing the Hong Kong Branch of Biomaterials seeks to promote further collaboration with the Main Centre with the goals of promoting synergy and a win-win cooperation between mainland China and Hong Kong in scientific research, talent cultivation, clinically driven novel biomaterials product design, and preclinical and clinical testing. It will thus become a model for the successful collaboration between the Hong Kong research institutions and the mainland CNERCs in the area of biomaterials. Such initiatives will facilitate close collaboration in translational medicine associated with biomaterial development and application
Rab32 facilitates Schwann cell pyroptosis in rats following peripheral nerve injury by elevating ROS levels
Abstract Background Peripheral nerve injury (PNI) is commonly observed in clinical practice, yet the underlying mechanisms remain unclear. This study investigated the correlation between the expression of a Ras-related protein Rab32 and pyroptosis in rats following PNI, and potential mechanisms have been explored by which Rab32 may influence Schwann cells pyroptosis and ultimately peripheral nerve regeneration (PNR) through the regulation of Reactive oxygen species (ROS) levels. Methods The authors investigated the induction of Schwann cell pyroptosis and the elevated expression of Rab32 in a rat model of PNI. In vitro experiments revealed an upregulation of Rab32 during Schwann cell pyroptosis. Furthermore,Ā the effect of Rab32 on the level of ROS in mitochondria in pyroptosis model has also been studied. Finally, the effects of knocking down the Rab32 gene on PNR were assessed, morphology, sensory and motor functions of sciatic nerves, electrophysiology and immunohistochemical analysis were conducted to assess the therapeutic efficacy. Results Silencing Rab32 attenuated PNI-induced Schwann cell pyroptosis and promoted peripheral nerve regeneration. Furthermore, our findings demonstrated that Rab32 induces significant oxidative stress by damaging the mitochondria of Schwann cells in the pyroptosis model in vitro. Conclusion Rab32 exacerbated Schwann cell pyroptosis in PNI model, leading to delayed peripheral nerve regeneration. Rab32 can be a potential target for future therapeutic strategy in the treatment of peripheral nerve injuries
Molecular co-assembled strategy tuning protein conformation for cartilage regeneration
Abstract The assembly of oligopeptide and polypeptide molecules can reconstruct various ordered advanced structures through intermolecular interactions to achieve protein-like biofunction. Here, we develop a āmolecular velcroā-inspired peptide and gelatin co-assembly strategy, in which amphiphilic supramolecular tripeptides are attached to the molecular chain of gelatin methacryloyl via intra-/intermolecular interactions. We perform molecular docking and dynamics simulations to demonstrate the feasibility of this strategy and reveal the advanced structural transition of the co-assembled hydrogel, which brings more ordered Ī²-sheet content and 10-fold or more compressive strength improvement. We conduct transcriptome analysis to reveal the role of co-assembled hydrogel in promoting cell proliferation and chondrogenic differentiation. Subcutaneous implantation evaluation confirms considerably reduced inflammatory responses and immunogenicity in comparison with type I collagen. We demonstrate that bone mesenchymal stem cells-laden co-assembled hydrogel can be stably fixed in rabbit knee joint defects by photocuring, which significantly facilitates hyaline cartilage regeneration after three months. This co-assembly strategy provides an approach for developing cartilage regenerative biomaterials
Nanofibrous polypeptide hydrogels with collagen-like structure as biomimetic extracellular matrix
Abstract Supramolecular peptides exhibit obvious similarities with collagen fibers in terms of self-assembly characteristics, nanofibrous structure, and responsiveness to external stimuli. Here, a series of supramolecular peptides were developed by altering the amino acid sequence, enabling the self-assembly of three types of 4-biphenylacetic acid (BPAA)-tripeptides into fibrous hydrogel through hydrogen bonding and ĻāĻ stacking under the influence of ion induction. Transmission electron and scanning electron microscopies revealed that the diameter of the fiber within nanofibrous hydrogels wasā~ā10 andā~ā40Ā nm, respectively, which was similar with the self-assembled collagen fibers. For this reason, these hydrogels could be considered as a biomimetic extracellular substitute. Meanwhile, the gelation concentration induced by ions was even lower than 0.66Ā wt%, with an elastic modulus ofā~ā0.27Ā kPa, corresponding to a water content of 99.34Ā wt%. In addition, the three supramolecular hydrogels were found to be good substrates for L929 cell adhesion and MC-3T3 cell proliferation. The overall results implied that BPAA-based hydrogels have a lucrative application potential as cell carriers. Graphical Abstrac
Efficient Delivery of DOX to Nuclei of Hepatic Carcinoma Cells in the Subcutaneous Tumor Model Using pH-Sensitive PullulanāDOX Conjugates
Additional file 1 of Rab32 facilitates Schwann cell pyroptosis in rats following peripheral nerve injury by elevating ROS levels
Additional file 1: Figure S1. The protective effect of Rab32 knockdown on mitochondria. A Representative transmission electron microscope image showing mitochondria morphological changes accompanying Schwann cell pyroptosis induced by LPS/ATP. Scale barā=ā2Ā Āµm. B Quantitative data of the average number of mitochondria per unit area. C Quantitative data of the average volume of mitochondria per unit area. **pā<ā0.01 compared to the LA/shRab32 group. *pā<ā0.05 compared to the LA/shRab32 group. Figure S2. Quantification of LDH release indicating Schwann cell damage. **pā<ā0.01 compared to the LA group. *pā<ā0.05 compared to the LA group. Figure S3. Representative transmission electron microscope image showing morphological changes accompanying Schwann cell pyroptosis induced by LPS/ATP. The black arrows represent the pores on the cell membrane, which is also one of the characteristic signs of pyroptosis. Scale barā=ā2Ā Āµm. Figure S4. The impact of Rab32 on mitochondrial morphology in Schwann cells following peripheral nerve injury. A Representative transmission electron microscope image showing mitochondrial morphological changes accompanying Schwann cell pyroptosis induced by PNI. Scale barā=ā2Ā Āµm. B Quantitative data of the average number of mitochondria per unit area. C Quantitative data of the average volume of mitochondria per unit area. **pā<ā0.01 compared to the PNI/shRab32 group. *pā<ā0.05 compared to the PNI/shRab32 group. Figure S5. Evaluation of the effect of MitoQ on pyroptosis in peripheral nerve injury. A Western blotting analysis was conducted to evaluate the levels of pyroptosis-associated proteins in nerve tissues. Ī²-actin was used as an internal control. BāD Levels of pyroptosis-associated proteins were quantified based on semi-quantitative band analysis. E Representative immunofluorescence images displayingĀ NLRP3 (red) and S100Ī² (green) in nerve tissues. **pā<ā0.01 compared to the PNI/M group. *pā<ā0.05 compared to the PNI/M group. Scale barā=ā20Ā Āµm