Catalytic oxygen production mediated by smart capsules to modulate elastic turbulence under a laminar flow regime

none11Liquid flow in microchannels is completely laminar and uniaxial, with a very low Reynolds number regime and long mixing lengths. To increase fluid mixing and solubility of reactants, as well as to reduce reaction time, complex three-dimensional networks inducing chaotic advection have to be designed. Alternatively, turbulence in the liquid can be generated by active mixing methods (magnetic, acoustic waves, etc.) or adding small quantities of elastic materials to the working liquid. Here, polyelectrolyte multilayer capsules embodying a catalytic polyoxometalate complex have been suspended in an aqueous solution and used to create elastic turbulence and to propel fluids inside microchannels as an alternative to viscoelastic polymers. The overall effect is enhanced and controlled by feeding the polyoxometalate-modified capsules with hydrogen peroxide, H2O2, thus triggering an on-demand propulsion due to oxygen evolution resulting from H2O2 decomposition. The quantification of the process is done by analysing some structural parameters of motion such as speed, pressure, viscosity, and Reynolds and Weissenberg numbers, directly obtained from the capillary dynamics of the aqueous mixtures with different concentrations of H2O2. The increases in fluid speed as well as the capsule-induced turbulence effects are proportional to the H2O2 added and therefore dependent on the kinetics of H2O2 dismutation.Zizzari A.; Bianco M.; Miglietta R.; del Mercato L. L.; Carraro M.; Soraru A.; Bonchio M.; Gigli G.; Rinaldi R.; Viola I.; Arima, V.Zizzari, A.; Bianco, M.; Miglietta, R.; del Mercato, L. L.; Carraro, M.; Soraru, A.; Bonchio, M.; Gigli, Giuseppe; Rinaldi, Rosaria; Viola, I.; Arima, V

Generic Delivery of Payload of Nanoparticles Intracellularly via Hybrid Polymer Capsules for Bioimaging Applications

Towards the goal of development of a generic nanomaterial delivery system and delivery of the ‘as prepared’ nanoparticles without ‘further surface modification’ in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb3+ was observed after internalization of LaF3:Tb3+(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification

Hybrid inorganic-organic capsules for efficient intracellular delivery of novel siRNAs against influenza A (H1N1) virus infection

This work was supported by ARUK project grant 21210 ‘Sustained and Controllable Local Delivery of Anti-inflammatory Therapeutics with Nanoengineered Microcapsules’. The work was also supported in part by Russian Foundation of Basic Research grants No. 16-33-50153 mol_nr, No. 16-33-00966 mol_a, Russian Science Foundation grant No. 15-15-00170 and Russian Governmental Program ‘‘Nauka’’, No. 1.1658.2016, 4002

Edible bio-based nanostructures: delivery, absorption and potential toxicity

The development of bio-based nanostructures as nanocarriers of bioactive compounds to specific body sites has been presented as a hot topic in food, pharmaceutical and nanotechnology fields. Food and pharmaceutical industries seek to explore the huge potential of these nanostructures, once they can be entirely composed of biocompatible and non-toxic materials. At the same time, they allow the incorporation of lipophilic and hydrophilic bioactive compounds protecting them against degradation, maintaining its active and functional performance. Nevertheless, the physicochemical properties of such structures (e.g., size and charge) could change significantly their behavior in the gastrointestinal (GI) tract. The main challenges in the development of these nanostructures are the proper characterization and understanding of the processes occurring at their surface, when in contact with living systems. This is crucial to understand their delivery and absorption behavior as well as to recognize potential toxicological effects. This review will provide an insight into the recent innovations and challenges in the field of delivery via GI tract using bio-based nanostructures. Also, an overview of the approaches followed to ensure an effective deliver (e.g., avoiding physiological barriers) and to enhance stability and absorptive intestinal uptake of bioactive compounds will be provided. Information about nanostructures potential toxicity and a concise description of the in vitro and in vivo toxicity studies will also be given.Joana T. Martins, Oscar L. Ramos, Ana C. Pinheiro, Ana I. Bourbon, Helder D. Silva and Miguel A. Cerqueira (SFRH/BPD/89992/2012, SFRH/BPD/80766/2011, SFRH/BPD/101181/2014, SFRH/BD/73178/2010, SFRH/BD/81288/2011, and SFRH/BPD/72753/2010, respectively) are the recipients of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE, Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes," REF.NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. We also thank to the European Commission: BIOCAPS (316265, FP7/REGPOT-2012-2013.1) and Xunta de Galicia: Agrupamento INBIOMED (2012/273) and Grupo con potencial de crecimiento. The support of EU Cost Action FA1001 is gratefully acknowledged

Plasma assisted immobilization of microcapsules for drug delivery on collagen-based matrices for peripheral nerve regeneration

The aim of this work was the superficial activation, by means of plasma treatments, of crosslinked collagen-based scaffolds for nerve regeneration, in order to immobilize anionic and cationic microcapsules (MCPs) for drug delivery. Matrices with axially oriented pores have the potential to improve the regeneration of peripheral nerves and spinal cord by physically supporting and guiding the growth of neural structures across the site of injury. To improve mechanical resistance and stability in water solutions, it is necessary to crosslink collagenous fibres by formation of amide bonds with consequent reduction of free amino and carboxylic groups useful for immobilization approach of drug delivery systems like MCPs. Plasma chemical processes represent a successful approach because allow polar groups to be grafted on the surface, without modifying the massive properties of the bulk. Plasma surface modification was performed in a capacitively-coupled rf (13.56 MHz) glass reactor fed with different precursors like N2, H2O, C2H4 to study the effect of plasma parameters on the chemical properties of the resulting material and its ability to improve the immobilization of polyelectrolyte MCPs. Cylindrical scaffolds were synthesized by freeze-drying technique and dehydrothermally crosslinked. Polyelectrolyte capsules were obtained by LbL method. Scaffolds were characterized by means of WCA and XPS. Fluorescence microscopy was used to verify MCPs immobilization. After treatments, scaffolds became hydrophilic and able to absorb water. The success of grafting, on the external surface and within the scaffold core, was clearly revealed. The obtained results demonstrate that plasma processing of cross-linked collagen allows to enhance MCPs immobilization and that, by changing the typology of functional groups on the plasma treated surfaces, a different attitude to immobilize negatively or positively charged MCPs is observed

Collagen-based matrices with axially oriented pores activated via plasma and decorated with polyelectrolyte microcapsules for drug delivery

Introduction Collagen matrices with properly designed porous structure have the potential to improve the regeneration of tissues like peripheral nerves, by physically supporting and guiding the growth of tissue structures across the site of injury [1]. Due to the formation of amide bonds during cross-linking of the scaffold, an abatement of groups naturally present on the collagen chains (e.g. NH2, COOH) occurs. Such groups are generally used as anchor moieties for biomolecules or drug delivery systems like microcapsules (MCPs) [2]. In this work, cylindrical collagen-based scaffolds with axially oriented pores, useful for peripheral nerve regeneration, were prepared and then subjected to plasma processing [3], with the aim of grafting polar groups on them. Materials and methods Synthesis of scaffolds- Collagen-based scaffolds with axially oriented pores were synthesized from an aqueous suspension of Type I collagen (3 wt%, Semed S, Kensey Nash Corp.) and dehydrothermally crosslinked, as described in the literature [1]. Synthesis of MCPs- Anionic and cationic capsules, carrying FITC- and RITC-labeled dextrans into the cavities, respectively, were obtained using the LbL method [2]. Plasma processes- performed at 13.56 MHz radio frequency (rf) were fed with N2 and H2O vapors by changing the gas feed composition. The total gas flow was maintained at 15 sccm, at 150 mTorr and 30 W with variable treatment time. Results and discussion Plasma treatments imparted immediate hydrophilicity and ability to absorb water to the scaffolds. For comparison, it should be noted that untreated crosslinked collagen scaffolds did not absorb water. Plasma treatments were able to effectively change the chemical characteristics of both the external and internal surface of the scaffolds. After MCPs immobilization, fluorescence microscopy clearly demonstrated that: surfaces functionalized by means of NH2 groups are able to support the immobilization of negatively charged MCPs; COOH plasma functionalized materials are able to support positively charged ones. Conclusions This paper demonstrates that plasma processing of cross-linked collagen is a powerful tool to enhance MCPs immobilization. Acknowledgments The Italian Regional project PON 02 00563 3448479 RINOVATIS for funding

Catalytic Self-Propulsion of Supramolecular Capsules Powered by Polyoxometalate Cargos

Multicompartment, spherical microcontainers were engineered through a layer-by-layer polyelectrolyte deposition around a fluorescent core while integrating a ruthenium polyoxometalate (Ru4POM), as molecular motor, vis-a-vis its oxygenic, propeller effect, fuelled upon H2O2 decomposition. The resulting chemomechanical system, with average speeds of up to 25 mu ms(-1), is amenable for integration into a microfluidic set-up for mixing and displacement of liquids, whereby the propulsion force and the resulting velocity regime can be modulated upon H2O2-controlled addition

Cytoskeletal Alterations and Biomechanical Properties of parkin-Mutant Human Primary Fibroblasts.

Parkinson’s disease (PD) is one of the most common neurodegenerative diseases. Genes which have been implicated in autosomal-recessive PD include PARK2 which codes for parkin, an E3 ubiquitin ligase that participates in a variety of cellular activities. In this study, we compared parkin-mutant primary fibroblasts, from a patient with parkin compound heterozygous mutations, to healthy control cells. Western blot analysis of proteins obtained from patient’s fibroblasts showed quantitative differences of many proteins involved in the cytoskeleton organization with respect to control cells. These molecular alterations are accompanied by changes in the organization of actin stress fibers and biomechanical properties, as revealed by confocal laser scanning microscopy and atomic force microscopy. In particular, parkin deficiency is associated with a significant increase of Young’s modulus of null-cells in comparison to normal fibroblasts. The current study proposes that parkin influences the spatial organization of actin filaments, the shape of human fibroblasts, and their elastic response to an external applied force