Development of Biocomposite Alginate-Cuttlebone-Gelatin 3D Printing Inks Designed for Scaffolds with Bone Regeneration Potential

Fabrication of three-dimensional (3D) scaffolds using natural biomaterials introduces valuable opportunities in bone tissue reconstruction and regeneration. The current study aimed at the development of paste-like 3D printing inks with an extracellular matrix-inspired formulation based on marine materials: sodium alginate (SA), cuttlebone (CB), and fish gelatin (FG). Macroporous scaffolds with microporous biocomposite filaments were obtained by 3D printing combined with post-printing crosslinking. CB fragments were used for their potential to stimulate biomineralization. Alginate enhanced CB embedding within the polymer matrix as confirmed by scanning electron microscopy (ESEM) and micro-computer tomography (micro-CT) and improved the deformation under controlled compression as revealed by micro-CT. SA addition resulted in a modulation of the bulk and surface mechanical behavior, and lead to more elongated cell morphology as imaged by confocal microscopy and ESEM after the adhesion of MC3T3-E1 preosteoblasts at 48 h. Formation of a new mineral phase was detected on the scaffold’s surface after cell cultures. All the results were correlated with the scaffolds’ compositions. Overall, the study reveals the potential of the marine materials-containing inks to deliver 3D scaffolds with potential for bone regeneration applications.     

A Therapeutic Potential for Marine Skeletal Proteins in Bone Regeneration

A vital ingredient for engineering bone tissue, in the culture dish, is the use of recombinant matrix and growth proteins to help accelerate the growth of cultivated tissues into clinically acceptable quantities. The skeletal organic matrices of calcifying marine invertebrates are an untouched potential source of such growth inducing proteins. They have the advantage of being ready-made and retain the native state of the original protein. Striking evidence shows that skeleton building bone morphogenic protein-2/4 (BMP) and transforming growth factor beta (TGF-β) exist within various marine invertebrates such as, corals. Best practice mariculture and the latest innovations in long-term marine invertebrate cell cultivation can be implemented to ensure that these proteins are produced sustainably and supplied continuously. This also guarantees that coral reef habitats are not damaged during the collection of specimens. Potential proteins for bone repair, either extracted from the skeleton or derived from cultivated tissues, can be identified, evaluated and retrieved using chromatography, cell assays and proteomic methods. Due to the current evidence for bone matrix protein analogues in marine invertebrates, together with the methods established for their production and retrieval there is a genuine prospect that they can be used to regenerate living bone for potential clinical use.     

Bone Regeneration of Rat Tibial Defect by Zinc-Tricalcium Phosphate (Zn-TCP) Synthesized from Porous Foraminifera Carbonate Macrospheres

Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.     

Effects of Nanofiber Scaffolds Coated with Nanoparticulate and Microparticulate Freeze Dried Bone Allograft on the Morphology,Adhesion, and Proliferation of Human Mesenchymal Stem Cells

Background:Freeze dried bone allograft nanoparticles on a nanofiber membrane may serve as an ideal scaffold for bone regeneration. This study aimed to assess the biological behavior of human MSCs in terms of proliferation and adhesion to nanoparticulate and microparticulate FDBA scaffolds on PLLA nanofiber membrane. Methods:In this experimental study, PLLA nanofiber scaffolds were synthesized by the electrospinning method. The FDBA nanoparticles were synthesized mechanically. The FDBA nanoparticles and microparticles were loaded on the surface of PLLA nanofiber membrane. A total of 64 scaffold samples in four groups of n-FDBA/PLLA, FDBA/PLLA, PLLA and control were placed in 24-well polystyrene tissue culture plates; 16 wells were allocated to each group. Data were analyzed using one-way ANOVA and Bonferroni test. Results:The proliferation rate of MSCs was significantly higher in the nanoparticulate group compared to the microparticulate group at five days (p = 0.034). Assessment of cell morphology at 24 hours revealed spindle-shaped cells with a higher number of appendages in the nanoparticulate group compared to other groups. Conclusion:MSCs on n-FDBA/PLLA scaffold were morphologically more active and flatter with a higher number of cellular appendages, as compared to FDBA/PLLA. It seems that the nanoparticulate scaffold is superior to the microparticulate scaffold in terms of proliferation, attachment, and morphology of MSCs in vitro.Key Words: Allografts, Bone regeneration, Mesenchymal stem cells, Nanofibers     

稻瘟病菌原生质体制备和再生的研究

 为建立稻瘟病菌转化体系，选用稻瘟病菌2539B为受体，用Novozyme-234或国产裂解酶分别消化该菌细胞壁，都获得了足够数量的原生质体，并具再生菌的能力，其效率大体相近。上述两种裂解酶按1 g鲜重菌丝加50 mg酶量，消化2 h即可获得4．65×10⁸细胞／mL密度的原生质体,制备的原生质体和稻瘟病菌分生孢子具有相似的习性。     

High Temperature and Humidity Effect on Biochemical Characteristics of Organically-Grown Parsnip Roots Compared to Garlic Bulbs

Plant Foods for Human Nutrition - Functional food with high concentrations of monosaccharides and antioxidants is important for quick replenishment of energy reserves and rehabilitation after...     

Selection of Nontarget Testing Organisms for ERA of GM Potato with Increased Resistance to Late Blight

The deliberate release of any genetically modified (GM) organism in the European Union requires an environmental risk assessment (ERA) prior to commercialisation, including impact assessment on nontarget organisms. We report from two expert workshops where a newly developed selection procedure for identification of ecologically relevant testing organisms was applied to the case of a GM potato with increased resistance to late blight, planned for cultivation in southern Scandinavia. Species known to contribute to important ecological functions in the receiving environment were selected in a stepwise procedure, to arrive at a practical number of ecologically relevant species that are likely to be exposed to the transgene and suitable for experimental testing. Four ecological functional categories were identified: herbivory and disease transmission, natural enemies, ecological soil processes and pollination. Among these, relevant nontarget species were identified for herbivores and soil living pathogens, natural enemies and decomposers/beneficial soil organisms. Out of a total of 16 herbivores, 17 soil-living pathogens, 49 natural enemies and 14 decomposers/beneficial soil organisms in the initial lists, 8 herbivores, 10 soil-living pathogens, 15 natural enemies and 11 decomposers/beneficial soil organisms were identified as possible testing organisms, based on ecological criteria. These findings are highly relevant for determining the scope and structure of an ERA of this type of GM potato. The selection procedure could not be completed because of insufficient information about tissue- and developmental stage-specific expression levels of the transgenic products for this particular GM potato. Thus, the case study illustrates some of the difficulties and knowledge gaps that limit the relevance and quality of ERA of GM plants.     

如东县稻麦周年高产制约因素及增产潜力分析

近年来,如东稻麦周年单产得到了恢复性增长,并取得一批高产典型,但仍存在着一些制约因素,本文在剖析当前农村发展的社会制约因素、技术应用制约因素的基础上,分析了未来稻麦生产的增产潜力。     

海风干扰形成朴树残桩萌枝更新的初步研究

在福州郊区琅岐岛保存完好的朴树防护林中,设置2条1 000 m×5 m的样带,调查由海风形成的朴树残桩基径、高度,萌枝个体数、基径、高度等,分析海风对朴树残桩萌枝更新规律。结果表明:海风形成的残桩基径在3.5~19.2 cm间,高度6~74 cm间,萌枝数量3~47株,萌枝高度4~200 cm;萌枝数量随着残桩基径的增大而增加,二者之间呈极显著的正相关关系:N=1.026 9 D1.0434(R2=0.477 6);萌枝高度随着残桩基径的增加而下降,二者之间呈极显著的负相关性:H=-38.973ln(D)+152.17(R2=0.330 4);萌枝数量与萌枝高度之间存在负相关性,即:H=-27.443 ln(N)+129.51(R2=0.373 5);残桩高度对萌枝数量和高度有一定的影响,残桩高度在30~40 cm时,其萌枝平均数量达到最多,残桩高度在20~30 cm时,其萌枝平均高度最高。     

深松耕法对甜菜增产效果的研究

试验表明,深松耕法不仅能改善土壤的物理性状,创造合理的土壤耕层,而且促进了植株的生长发育。研究看出,土地深松后的甜菜生育期内叶面积指数增加了0.05～0.31;干物质积累强度增加了0.465g/(株·d);叶面积指数达3以上的净同化率增加0.34～0.73g/(m~2·d)。3年平均根增产15.5％,含糖率增加1.73度,产糖量增加27.6％。     

不同产量水平夏玉米杂交种对水分的生理响应研究

在大田条件下,通过两不同产量水平玉米杂交种生育后期对水分的生理响应研究,结果表明不同品种对水分的生理响应差异明显.产量较高的郑单14(ZD14)对水分较为敏感,在足灌条件下具有较高的超氧化物岐化酶(SOD)、过氧化物酶(POD)活性,较高的叶绿素及可溶性蛋白含量以及较低的丙二醛(MDA)含量;而产量较低的丹玉13(DY13)的SOD、POD活性和可溶性蛋白质含量均在节灌时最高,其次为足灌,干旱时最低。     

转基因生物新品种培育科技重大专项（2008ZX 080022003）；西北农林科技大学基本科研业务费专项资金（CX200903）；国家“863”计划项目（2011AA100501）。

为了明确农杆菌侵染普通小麦大龄幼胚对幼苗再生及生长发育的影响,以普通小麦基因型小偃22、西农1376、西农889为主区,农杆菌菌液浓度(OD600值分别为0、0.5、1.0、1.5)为副区,采用裂区设计,对农杆菌侵染大龄幼胚后幼苗再生及生长发育相关性状进行了测定。结果表明,不同小麦基因型对农杆菌侵染的敏感程度不同。不同浓度农杆菌侵染小麦大龄幼胚后,初期幼苗再生成苗率、鲜重、株高和根长并未随菌液浓度变化而变化;在幼苗生长发育过程中,随着农杆菌菌液浓度的提高,小麦幼苗叶绿素含量和SOD活性呈下降趋势,而幼苗POD活性、CAT活性和MDA含量呈上升趋势,且当菌液浓度大于等于1.0(OD600)时与对照呈现显著差异。综合农杆菌对再生幼苗生理生化指标的影响,认为当农杆菌菌液浓度达到1.0(OD600值)以上时将对幼苗的生长发育造成严重伤害。     

江苏沿海滩涂盐碱地植棉优势和潜力分析

分析了江苏省沿海滩涂盐碱地开发和利用现状,阐述了江苏省沿海滩涂盐碱地植棉的可行性和存在问题,提出了加快推进江苏省沿海滩涂盐碱地植棉对策和建议。     

Potential use of exogenous lipases for DATEM replacement to modify the rheological and thermal properties of wheat flour dough

The effect of two lipases and DATEM at different concentrations on the rheological and thermal properties of white and whole wheat flour doughs was determined by farinograph, extensograph, texture analyzer and differential scanning calorimetry. Lipases provided similar or better results than that of DATEM on decreasing softening degree and stickiness, and increasing stability, maximum resistance to extension and hardness. Extensibility and energy did not change with lipases, but decreased with DATEM. Lipases and DATEM slightly modified the transition temperatures and enthalpies of ice-melting and starch gelatinization, but significantly increased the moisture and unfrozen water contents, and decreased the solid concentration in unfrozen water. The greatest effect of lipases was observed on decreasing the peak temperature and increasing the enthalpy of amylose–lipid complex dissociation. The changes in the rheological and thermal properties were almost independent of the concentration levels tested, and were mostly reduced when whole wheat flour was used. The improvement in the dough properties by lipases is possibly related to the in situ formation of surface active compounds from endogenous flour lipids. Presumably, these compounds are already located in the right positions in dough, where they might have higher interaction potentials than DATEM with the dough components.     

茶树修剪更新周期的探讨──据鲜叶产量和品质的变化趋势所作的推论

根据茶树在台刈更新后茶叶产量和自然品质的变化趋势，推导出了茶树和台刈更新适宜周期。在通常载培条件下，其更新周期为１０─１１年；若侧重于品质，则以９─１０年为宜；若侧重于产量，则以１３年为其适期。     

玉米-大豆轮作体系下连续4年增施有机肥对玉米产量和子粒品质的影响

利用典型黑土区玉米-大豆轮作定位试验,设5个处理,即不施肥(NoF)、玉米连作正常施用化肥(LZ)、玉米-大豆轮作正常施用化肥(CF)、玉米-大豆轮作正常施用化肥+15 000 kg/hm²有机肥(CF+15T)和玉米-大豆轮作正常施用化肥+30 000 kg/hm²有机肥(CF+30T),研究连续4年增施有机肥后对玉米产量及构成要素和子粒中蛋白质、氨基酸、可溶性糖、淀粉、矿质营养元素含量的影响。结果表明,同CF处理相比,LZ处理玉米产量比CF处理降低15%,连续4年增施有机肥后玉米产量呈增加趋势,CF+15T处理和CF+30T处理玉米产量比CF处理高8.8%和13%。单施化肥处理下连作与轮作玉米子粒品质指标差异不大,轮作处理后连续4年增施有机肥处理的玉米子粒中游离氨基酸、可溶性糖和淀粉含量随着施用有机肥的量增加而增加,对玉米子粒蛋白质含量影响不大。同LZ和CF处理相比,连续4年增施有机肥显著提高玉米子粒中K、Na、Mg和P含量,Ca、Mn、Fe和Zn含量无显著变化。因此,黑土区玉米连作减产,对品质影响不大。玉米-大豆轮作制度下连续4年增施1...     

sAGP基因增强表达对马铃薯淀粉和还原糖的影响及安全性评价

本文主要介绍了转sAGP马铃薯株系中淀粉和还原糖含量的变化,以及sAGP基因超量表达对淀粉理化性质的影响,同时介绍了马铃薯转基因安全性评价的相关研究及转sAGP基因马铃薯安全性评价中间试验的进展     

Influence of Fucoidan Extracts from Different Fucus Species on Adult Stem Cells and Molecular Mediators in In Vitro Models for Bone Formation and Vascularization

Fucoidans, sulfated polysaccharides extracted from brown algae, are marine products with the potential to modulate bone formation and vascularization processes. The bioactivity and safety of fucoidans are highly associated with their chemical structure, which may vary with algae species and extraction method. Thus, in depth evaluation of fucoidan extracts in terms of endotoxin content, cytotoxicity, and their detailed molecular biological impact on the individual cell types in bone is needed. In this study, we characterized fucoidan extracts from three different Fucus species including Fucus vesiculosus (Fv), Fucus serratus (Fs), and Fucus distichus subsp. evanescens (Fe) for their chemical features, endotoxin content, cytotoxicity, and bioactive effects on human outgrowth endothelial cells (OEC) and human mesenchymal stem cells (MSC) as in vitro models for bone function and vascularization. Extracts contained mainly high molecular weight (HMW) fucoidans and were free of endotoxins that may cause inflammation or influence vascularization. OEC tolerated fucoidan concentrations up to 200 µg/mL, and no indication of cytotoxicity was observed. The inflammatory response, however, investigated by real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) and endothelial barrier assessed by impedance measurement differed for the individual extracts. MSC in comparison with endothelial cells were more sensitive to fucoidans and showed partly reduced metabolic activity and proliferation at higher doses of fucoidans. Further results for MSC indicated impaired osteogenic functions in alkaline phosphatase and calcification assays. All tested extracts consistently lowered important molecular mediators involved in angiogenesis, such a VEGF (vascular endothelial growth factor), ANG-1 (angiopoietin 1), and ANG-2 (angiopoietin 2), as indicated by RT-PCR and ELISA. This was associated with antiangiogenic effects at the functional level using selected extracts in co-culture models to mimic bone vascularization processes during bone regeneration or osteosarcoma.