Recent advances using gold nanoparticles as a promising multimodal tool for tissue engineering and regenerative medicine

Gold nanoparticles (AuNPs) have arisen a lot of interest in the clinical realms of nanomedicine. Despite the large advances made in cancer research using AuNPs, their use in tissue engineering and regenerative medicine (TERM) is still in its infancy. Herein, it is discussed the properties, functionalization, and emerging use of AuNPs as a multifunctional and multimodal platform for drug delivery, phototherapy, diagnostic and cell imaging purposes. Moreover, the recent reports related to the ability of AuNPs to enhance stem cell differentiation for bone tissue engineering, to enhance the mechanical and adhesive properties of scaffolds and surface topography to guide cell behaviors are addressed.     

DMA thermal analysis of different parts of potato tuber

Dynamic mechanical analysis (DMA) was applied to three potato tissues (‘cortex’, ‘pith’, and ‘side’ surface) of two cultivars (more waxy ‘Nicola’ and more mealy ‘Saturna’) in temperature scans in the range 30–90 °C and constant air humidity of 90%. The obtained scans indicate peaks in both storage and loss module of elasticity (SM and LM, respectively) at temperatures higher than 70 °C – so called ‘starch’ peak (SP) – as was observed previously. The peak value increase with increasing potato dry matter (DM) content, below DM content approximately 14% no SP is observed (‘Nicola pith’). Slope analysis of the basic parameters: SM, LM, and loss tangent (LT) was performed and further characteristic points on the temperature plots were found: (i) in temperature range A (30–40 °C) maximum of SM and LM and minimum of LT, (ii) in temperature range B (40–50 °C) minimum of SM and LM slopes corresponding to point of inflection on SM-T and LM-T plots, (iii) at about 50 °C, big peak in LT in side tissue only, (iv) at about 70 °C just prior the ‘starch’ peak, big peak in LT that is more marked in ‘pith’; this peak denoted as ‘I’ influenced the ‘starch’ peak ‘II’. It was found that both cultivar and part of the tuber influences the DMA temperature plots.     

Synthesis of a Kind of Temperature-responsive Cell Culture Surface for Corneal Sheet

In this study,acrylic acid(AA) and 4-azidoaniline were used to modify poly(N-isopropylacrylamide)(NIPAAm) in order to fabricate temperature-responsive surface for corneal epithelia cell adhesion and detachment.First,NIPAAm was copolymerized with acrylic acid.Then,the copolymer was coupled with azidoaniline to synthesize AzPhPIA,derivative of p(NIPAAm-co-AA),which possesses both thermo-and photo-sensitivities.Second,the synthesized copolymer was characterized by high performance liquid chromatography(HPLC),F...     

Fabrication and characterization of silk/forsterite composites for tissue engineering applications

In this research, novel composite scaffolds consisting of silk fibroin and forsterite powder were prepared by a freeze-drying method. In addition, the effects of forsterite powder contents on the structure of the scaffolds were investigated to provide an appropriate composite for bone tissue engineering applications. The morphology studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques showed that the forsterite ceramic was well distributed throughout the structures of SF/forsterite scaffolds. Furthermore, the forsterite powder (up to 40 wt%) was homogenously distributed within the silk fibroin as a matrix.     

Injury Mechanisms of Lactic Acid Bacteria Starter Cultures During Spray Drying: A Review

Lactic acid bacteria (LAB) starter cultures can be processed by many drying techniques, among which spray drying has great potential. However, injuries of LAB during spray drying lead to a low survival rate. The microbial injuries of LAB during spray drying are specifically induced by dehydration inactivation, thermal inactivation, and balance between the two. To reduce the drying temperature, new drying techniques based on spray drying were tried; that is, low-temperature vacuum–spray drying and spray–freeze drying.     

Surface hierarchical porosity in poly (ɛ-caprolactone) membranes with potential applications in tissue engineering prepared by foaming in supercritical carbon dioxide

This article describes the preparation of porous poly (ɛ-caprolactone), PCL, membranes by supercritical CO₂ (SCCO₂) foaming, displaying surface hierarchical macroporosity which could be tailored by careful control of the pressure, in the range of 150–250 bar, and depressurization processes in several steps, showing also pore interconnectivity between both membrane faces. The membranes exhibited two distinct types of surface macroporosity, the larger with diameter sizes of 300–500 μm were surrounded by and also composed of smaller pores of 15–50 μm (same size as inner pores). Membranes were prepared by solvent casting and submitted to different SCCO₂ foaming. Parameters such as membrane thickness, CO₂ flow, foaming time, pressure, temperature and the depressurization processes (rate and profiles), were varied to determine their influence on final porosity and to decipher which parameters were the most critical ones in terms of surface hierarchical pore organization. No remarkable changes in PCL crystallinity were found when membranes were processed under SCCO₂. Finally, biological evaluation of the porous membranes was achieved by seeding human skin fibroblasts on the prepared membranes. The results, in terms of cell adhesion, spreading, proliferation and metabolic activity indicate that these membranes could hold promise for the fabrication of meshes with controlled porosity for tissue engineering applications.     

发酵香肠菌种的筛选及鉴定

本文从混合发酵剂中筛选菌株,确定用于发酵香肠生产的菌株名称,并对其筛选出的菌种进行生化鉴定,结果如下:RFx1为植物乳杆菌,RF261为德氏乳杆菌,AFx1为变异微球菌,ALx3为肉糖葡萄球菌.     

Inhibition of Neuronal Necroptosis Mediated by RIPK1 Provides Neuroprotective Effects on Hypoxia and Ischemia In Vitro and In Vivo

Ischemic brain injury is a widespread pathological condition, the main components of which are a deficiency of oxygen and energy substrates. In recent years, a number of new forms of cell death, including necroptosis, have been described. In necroptosis, a cascade of interactions between the kinases RIPK1 and RIPK3 and the MLKL protein leads to the formation of a specialized death complex called the necrosome, which triggers MLKL-mediated destruction of the cell membrane and necroptotic cell death. Necroptosis probably plays an important role in the development of ischemia/reperfusion injury and can be considered as a potential target for finding methods to correct the disruption of neural networks in ischemic damage. In the present study, we demonstrated that blockade of RIPK1 kinase by Necrostatin-1 preserved the viability of cells in primary hippocampal cultures in an in vitro model of glucose deprivation. The effect of RIPK1 blockade on the bioelectrical and metabolic calcium activity of neuron-glial networks in vitro using calcium imaging and multi-electrode arrays was assessed for the first time. RIPK1 blockade was shown to partially preserve both calcium and bioelectric activity of neuron-glial networks under ischemic factors. However, it should be noted that RIPK1 blockade does not preserve the network parameters of the collective calcium dynamics of neuron-glial networks, despite the maintenance of network bioelectrical activity (the number of bursts and the number of spikes in the bursts). To confirm the data obtained in vitro, we studied the effect of RIPK1 blockade on the resistance of small laboratory animals to in vivo modeling of hypoxia and cerebral ischemia. The use of Necrostatin-1 increases the survival rate of C57BL mice in modeling both acute hypobaric hypoxia and ischemic brain damage.     

FeNi@SiO2磁性纳米复合粒子的制备及磁热性能

大量制备磁热性能优异的磁性纳米粒子对磁热疗和组织复温的生物学应用具有理论价值.本研究通过高温电弧法制备FeNi磁性纳米颗粒,通过超声-沉降分级筛分得到平均粒径为80 nm的FeNi纳米颗粒,通过溶胶-凝胶法得到平均粒径为100 nm,SiO2壳层厚度为15～20 nm的FeNi@SiO2纳米复合粒子.超导量子干涉仪测定...