Relationships between seed number, gibberellin and abscisic acid levels and ripening in Cabernet Sauvignon grape berries

In grapes of Cabernet Sauvignon, berry growth, content of anthocyanin and hormonal composition affected by seed number were investigated.Gibberellin-like substance content showed highest values 45 d after anthesis, while abscisic acid content (on a per-berry basis) had two peaks, the first one just after berry set, the second coinciding with ripening phenomenon.Seed number was positively correlated with the cöncentrations of gibberellinlike substances and abscisic acid (on a per-berry basis). One-seeded berries, however, had a higher amount of anthocyanin than two or three-seeded ones.Beziehungen zwischen Anzahl der Samen sowie Gibberellin- und Abscisinsäuregehalt und Reifeverlauf der Traubenbeeren bei Cabernet SauvignonBei den Trauben von Cabernet Sauvignon wurden das Beerenwachstum, der Anthocyangehalt und die Zusammensetzung der Phytohormone in Beziehung zur Anzahl der Samen untersucht.Die Gibberellinaktivität erreichte 45 d nach der Anthese ihren höchsten Stand, während der Abscisinsäuregehalt (je Beere) zwei Maxima zeigte; das erste trat kurz nach dem Beerenansatz auf, das zweite fiel mit dem Beginn der Beerenreife zusammen. Die Anzahl der Samen war positiv mit der Gibberellinaktivität und der Abscisinsäurekonzentration (je Beere) korreliert. Einsamige Beeren. wiesen jedoch einen höheren Anthocyangehalt als zwei- oder dreisamige Beeren auf

In Vitro Production of Calcified Bone Matrix onto Wool Keratin Scaffolds via Osteogenic Factors and Electromagnetic Stimulus

Pulsed electromagnetic field (PEMF) has drawn attention as a potential tool to improve the ability of bone biomaterials to integrate into the surrounding tissue. We investigated the effects of PEMF (frequency, 75 Hz; magnetic induction amplitude, 2 mT; pulse duration, 1.3 ms) on human osteoblast-like cells (SAOS-2) seeded onto wool keratin scaffolds in terms of proliferation, differentiation, and production of the calcified bone extracellular matrix. The wool keratin scaffold offered a 3D porous architecture for cell guesting and nutrient diffusion, suggesting its possible use as a filler to repair bone defects. Here, the combined approach of applying a daily PEMF exposure with additional osteogenic factors stimulated the cells to increase both the deposition of bone-related proteins and calcified matrix onto the wool keratin scaffolds. Also, the presence of SAOS-2 cells, or PEMF, or osteogenic factors did not influence the compression behavior or the resilience of keratin scaffolds in wet conditions. Besides, ageing tests revealed that wool keratin scaffolds were very stable and showed a lower degradation rate compared to commercial collagen sponges. It is for these reasons that this tissue engineering strategy, which improves the osteointegration properties of the wool keratin scaffold, may have a promising application for long term support of bone formation in vivo

Mesoporous bioactive glass as a multifunctional system for bone regeneration and controlled drug release

Purpose: Coupling the potential for bone regeneration and the ability for in situ controlled drug release in a single device is a challenging field of research in bone tissue engineering; in an attempt to pursue this aim, mesoporous bioactive glass (MBG) membranes belonging to the SiO2-P2O5-CaO ternary system were produced and characterized. Methods: The glass was synthesized via a sol-gel route coupled with an evaporation-induced self-assembly process by using a non-ionic block co-polymer as a mesostructure former. MBG structure and morphology, as well as mesopores size and shape, were investigated by x-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption measurements. In vitro bioactivity was investigated by soaking MBG membranes in simulated body fluid (SBF) for different time frames. Ibuprofen was encapsulated into MBG pores and drug release kinetics in SBF were assessed. Biological tests by using SAOS-2 cells were performed to assess the material cytocompatibility. Results: The material revealed significant ability to induce hydroxyapatite formation on its surface (bioactivity). Drug release kinetics in SBF are very similar to those obtained for mesoporous silica having mesopore size comparable to that of the prepared MBG (∼5 nm). No evidence of cell viability depression was detected during in vitro culture, which demonstrates the good biological compatibility of the material. Conclusions: The easiness of tailoring and shaping, the highly bioactive and biocompatible behavior, and the drug uptake/release ability of the prepared materials may suggest their use as "smart" multifunctional grafts for bone reconstructive surgery

Atmospheric pressure non-equilibriumplasma for the production of composite materials

In the evolving field of tissue engineering, continuous advances are required to improve scaffold design and fabrication to obtain biomimetic supports for cell adhesion, proliferation, penetration and differentiation. Both electrospun fibrous scaffolds and hydrogels are used in this field since they well reproduce the structure of the extracellular matrix (ECM) of many biological tissues. Limitations of these two types of materials can be overcome through their combination, by developing composite structures combining enhanced mechanical properties (provided by the fibrous components) and improved cell penetration (provided by the gel phase) in a superior ability to mimic natural ECM that is constituted by both a fibrous protein network and a hydrogel matrix. Here we develop new composite materials made of electrospun PLLA scaffolds and poly(amidoamine) hydrogels with different degrees of crosslinking. To promote compatibilization and good adhesion between the two materials, surface chemical reactions between hydrogels and PLLA mats are induced by inserting amino functional groups on electrospun PLLA mats by means of atmospheric pressure non-thermal plasma. Results will be presented concerning the exposure of PLLA substrates to the plasma region generated by a Dielectric Barrier Discharge at atmospheric pressure, driven by a HV Amplifier connected to a function generator operating with a microsecond rise time and operated in N2. Surface and solid-state thermo-mechanical characterizations of plasma treated substrates and of resulting composite materials at different crosslinking degrees are presented. Results of mechanical tests show a high adhesion between hydrogel and plasma treated PLLA electrospun mats, underlining the opportunity to use atmospheric non-thermal plasmas to fabricate a composite starting from two materials otherwise physically incompatible. Potential effects of nanofibrous-hydrogel were evaluated by investigating pluripotent stem cells response

Extra-small gold nanospheres decorated with a thiol-functionalized biodegradable and biocompatible linear polyamidoamine as nanovectors of anticancer molecules

Gold nanoparticles are elective candidate for cancer therapy. Current efforts are devoted to developing innovative methods for their synthesis. Besides, understanding their interaction with cells have become increasingly important for their clinical application. This work aims to describe a simple approach for the synthesis of extra-small gold nanoparticles for breast cancer therapy. In brief, a biocompatible and biodegradable polyamidoamine (named AGMA1-SH), bearing 20%, on a molar basis, thiol-functionalized repeat units, is employed to stabilize and coat extra-small gold nanospheres of different sizes (2.5, 3.5, and 5 nm in gold core), and to generate a nanoplatform for the link with Trastuzumab monoclonal antibody for HER2-positive breast cancer targeting. Dynamic light scattering, transmission electron microscopy, ultraviolet visible spectroscopy, X-ray powder diffraction, circular dichroism, protein quantification assays are used for the characterization. The targeting properties of the nanosystems are explored to achieve enhanced and selective uptake of AGMA1-SH-gold nanoparticles by in vitro studies against HER-2 overexpressing cells, SKBR-3 and compared to HER-2 low expressing cells, MCF-7, and normal fibroblast cell line, NIH-3T3. In vitro physicochemical characterization demonstrates that gold nanoparticles modified with AGMA1-SH are more stable in aqueous solution than the unmodified ones. Additionally, the greater gold nanoparticles size (5-nm) is associated with a higher stability and conjugation efficiency with Trastuzumab, which retains its folding and anticancer activity after the conjugation. In particular, the larger Trastuzumab functionalized nanoparticles displays the highest efficacy (via the pro-apoptotic protein increase, anti-apoptotic components decrease, survival-proliferation pathways downregulation) and internalization (via the activation of the classical clathrin-mediated endocytosis) in HER-2 overexpressing SKBR-3 cells, without eliciting significant effects on the other cell lines. The use of biocompatible AGMA1-SH for producing covalently stabilized gold nanoparticles to achieve selective targeting, cytotoxicity and uptake is completely novel, offering an important advancement for developing new anticancer conjugated-gold nanoparticles

Ultrasound stimulus to enhance the bone regeneration capability of gelatin cryogels

In the present study, gelatin-based cryogels have been seeded with human SAOS-2 osteoblasts. In order to overcome the drawbacks associated with in vitro culture systems, such as limited diffusion and inhomogeneous cell-matrix distribution, this work describes the application of ultrasounds (average power, 149 mW; frequency, 1.5 MHz) to physically enhance the cell culture in vitro. The results indicate that the physical stimulation of cell-seeded gelatin-based cryogels upregulates the bone matrix production

Heterogeneity Governs 3D-Cultures of Clinically Relevant Microbial Communities

The intrinsic heterogeneity of bacterial niches should be retained in in vitrocultures to represent the complex microbial ecology. As a case study,mucin-containing hydrogels -CF-Mu3Gel - are generated by diffusion-inducedgelation, bioinspired on cystic fibrosis (CF) mucus, and a microbial nichechallenging current therapeutic strategies. At breathing frequency, CF-Mu3Gelexhibits aG′andG′′equal to 24 and 3.2 Pa, respectively. Notably, CF-Mu3Gelexhibits structural gradients with a gradual reduction of oxygen tensionacross its thickness (280–194μmol L−1). Over the culture period, a steepdecline in oxygen concentration occurs just a few millimeters below theair–mucus interface in CF-Mu3Gel, similar to those of CF airway mucus.Importantly, the distinctive features of CF-Mu3Gel significantly influencebacterial organization and antimicrobial tolerance in mono- and co-cultures ofStaphylococcus aureusandPseudomonas aeruginosathat standard culturesare unable to emulate. The antimicrobial susceptibility determined inCF-Mu3Gel corroborates the mismatch on the efficacy of antimicrobialtreatment between planktonically cultured bacteria and those in patients.With this example-based research, new light is shed on the understanding ofhow the substrate influences microbial behavior, paving the way for improvedfundamental microbiology studies and more effective drug testing anddevelopment

Gold nanoparticles decorated with polyamidoamines for the delivery of anticancer drugs: synthesis and biological characterization

Despite remarkable successes in the treatment of breast cancer, some challenges remain. Gold nanoparticles may prove valuable in addressing these problems owing to their unique characteristics that make them elective agents for the conjugation with drugs and for photothermal therapy [1]. The potential toxicity of AuNPs remains a major hurdle that impedes their use in clinical settings. In this study, stable and biocompatible colloidal AuNPs (4-10 nm) were obtained by their functionalization with biocompatible stabilizing polymers (polyamidoamines, PAA). Sequentially, coated-AuNPs were used as platform for the conjugation of anticancer drugs (Fig. 1). AuNPs were conjugated with Herceptin, a chemotherapic agent used to treat breast cancer and their efficacy was evaluated in vitro. Two breast cancer cell lines were used (SKBR-3 and MCF-7) and compared with fibroblast-like cell line (NIH-3T3). Preliminary biological investigation showed that polymer coated-AuNPs functionalized with Herceptin led to increased efficacy and specificity for target cells in comparison with free drug and uncoated AuNPs, consistent with the endocytosis capability of the nanoparticles in the target cancer cells

A Non-Targeted Approach Unravels the Volatile Network in Peach Fruit

Volatile compounds represent an important part of the plant metabolome and are of particular agronomic and biological interest due to their contribution to fruit aroma and flavor and therefore to fruit quality. By using a non-targeted approach based on HS-SPME-GC-MS, the volatile-compound complement of peach fruit was described. A total of 110 volatile compounds (including alcohols, ketones, aldehydes, esters, lactones, carboxylic acids, phenolics and terpenoids) were identified and quantified in peach fruit samples from different genetic backgrounds, locations, maturity stages and physiological responses. By using a combination of hierarchical cluster analysis and metabolomic correlation network analysis we found that previously known peach fruit volatiles are clustered according to their chemical nature or known biosynthetic pathways. Moreover, novel volatiles that had not yet been described in peach were identified and assigned to co-regulated groups. In addition, our analyses showed that most of the co-regulated groups showed good intergroup correlations that are therefore consistent with the existence of a higher level of regulation orchestrating volatile production under different conditions and/or developmental stages. In addition, this volatile network of interactions provides the ground information for future biochemical studies as well as a useful route map for breeding or biotechnological purposes

Monoclonal Antibodies against Accumulation-Associated Protein Affect EPS Biosynthesis and Enhance Bacterial Accumulation of Staphylococcus epidermidis

Because there is no effective antibiotic to eradicate Staphylococcus epidermidis biofilm infections that lead to the failure of medical device implantations, the development of anti-biofilm vaccines is necessary. Biofilm formation by S. epidermidis requires accumulation-associated protein (Aap) that contains sequence repeats known as G5 domains, which are responsible for the Zn2+-dependent dimerization of Aap to mediate intercellular adhesion. Antibodies against Aap have been reported to inhibit biofilm accumulation. In the present study, three monoclonal antibodies (MAbs) against the Aap C-terminal single B-repeat construct followed by the 79-aa half repeat (AapBrpt1.5) were generated. MAb18B6 inhibited biofilm formation by S. epidermidis RP62A to 60% of the maximum, while MAb25C11 and MAb20B9 enhanced biofilm accumulation. All three MAbs aggregated the planktonic bacteria to form visible cell clusters. Epitope mapping revealed that the epitope of MAb18B6, which recognizes an identical area within AapBrpt constructs from S. epidermidis RP62A, was not shared by MAb25C11 and MAb20B9. Furthermore, all three MAbs were found to affect both Aap expression and extracellular polymeric substance (EPS, including extracellular DNA and PIA) biosynthesis in S. epidermidis and enhance the cell accumulation. These findings contribute to a better understanding of staphylococcal biofilm formation and will help to develop epitope-peptide vaccines against staphylococcal infections