Micro, nano encapsulation methods for sustained release drug formulations and biomimetic applications

The Layer-by-Layer (LbL) assembly technique was used to obtain a new type of protein/polyphenol microcapsule based on naturally occurring polyphenol (-)-epigallocatechin gallate (EGCG) and gelatin, type A. The dependence of permeability on the molecular weight of permeating substances was studied and compared with commonly used polyallylamine/polystyrene sulfonate capsules. A quartz crystal microbalance was used to monitor the regularities of EGCG adsorption in alternation with type A and B Gelatins and electrophoretic mobility measurements were used that indicated that the nature of assembly was dependent on Gelatin properties. It was shown that EGCG retains its antioxidant activity in the LbL assemblies. Natural polyphenols, with previously demonstrated anti-cancer potential, EGCG, tannic acid, curcumin, and theaflavin, were encased in gelatin-based 200-nm nanoparticles consisting of a soft gel-like interior with or without a surrounding LbL-shell of polyelectrolytes (polystyrene sulfonate/polyallylamine hydrochloride, polyglutamic acid/poly-L-lysine, dextran sulfate/protamine sulfate, carboxymethyl cellulose/Gelatin, type A) assembled using the LbL technique. The characteristics of polyphenol loading and the factors affecting their release from the nanocapsules were investigated. Nanoparticle-encapsulated EGCG retained its biological activity and blocked hepatocyte growth factor (HGF) induced intracellular signaling in the breast cancer cell-line MBA-MD-231 as potently as free EGCG. Since electrostatic LbL nano-assembly is proven to be a suitable method for surface modifications on charged templates, we also used this technique for nano-coating of the phototrophic purple sulfur bacterium Allochromatium Vinosum with different synthetic and biocompatible polyelectrolyte combinations in order to investigate its biomimetic applications as related to drug delivery. The contact mechanisms between the cell surface and the insoluble elemental sulfur was investigated and studied because this step is essential for elemental sulfur uptake. Furthermore, modified uptake of sulfide by the encapsulated cells was also investigated. Growth experiments, after coating of the cells, showed that the surface charge of the bacteria neither affected the uptake of sulfide nor the contact formation between the cells and elemental sulfur. However, an increasing number of layers assembled on the cells slowed or inhibited the uptake of sulfide and elemental sulfur depending on the polymer combination used for coating. This indicated that LbL self-assembly makes it a suitable method for investigation of cell-surface related aspects in microbiology. After using LbL assembly successfully for coating microbes, we coated microbial spores in a sheath of functionalized nanofilms. Bacterial spores were encapsulated in organized ultrathin shells using LbL assembly in order to assess the biomaterial as a suitable core and determine the physiological effects of the coating. The coated spores were viable but the kinetics and extent of germination were changed from control spores in all instances. The results and insight gained from the experiments may be used to design various bioinspired systems. The spores can be made dormant for a desired amount of time using LbL encapsulation technique and can be made active when desired. In this work with LbL nanoassemly, we performed polyphenol based formulations and also modified the bacterial surface to study the effects of encapsulation on the uptake of various compounds. (Abstract shortened by UMI.

Study of Variation in Upper Air Density Over India

The paper presents the seasonal variations and distribution of atmospheric density in the upper air over Indian region. The study reveals the density gradient has a down slope from North to South during winter and South to North, upto 200 mb level in summer. At 850 mb level the isopyenic lines forms a shallow through over East coast and at 700 mb level Bombay-Poona region while over the rest of the country the isopyenics show no special features. At 500 mb level three is a well marked trough of density over North Western India. Above 200 mb level an altogether different picture throughout the year is noticed

The case of veterinary interprofessional practice: From one health to a world of its own

BACKGROUND: Research regarding the veterinary professions' involvement in interprofessional practice and education (IPE), either with health care professionals as part of One Health, or specifically within the veterinary health care team, is sparse. PURPOSE: To investigate veterinary interprofessional working and learning in veterinary practices; then ultimately to make recommendations for IPE. METHOD: Two case studies in typical but contrasting practices were conducted. The study consisted of three sequential and complementary weeks: 1) observing the whole team, 2) shadowing selected focus individuals from each profession and 3) interviewing focus individuals regarding teamwork. Triangulation was achieved by synthesis of emergent themes from observational field notes and interview transcripts. DISCUSSION: Facilitators to interprofessional practices included hierarchy, trust and value, different perspectives, formal infrastructure and professionalization. Challenges included hierarchy, spatial and temporal work patterns, professional motivations, and error and blame. CONCLUSION: The veterinary and human health care fields face similar interprofessional challenges. Real life observations, as described here, can provide important insight relevant to the design of IPE initiatives

Improving conflict support environments with information regarding social relationships

"Advances in artificial intelligence : IBERAMIA 2014 : 14th Ibero-American Conference on AI, Santiago de Chile, Chile, November 24-27, 2014, proceedings", ISBN 978-3-319-12026-3Having knowledge about social interactions as a basis for informed decision support in situations of conflict can be determinant. However, lower attention is given to the social network interpretation process in conflict management approaches. The main objective of the work presented here is to identify how the parties’ social networks correlate to their negotiation performance and how this can be formalized. Therefore, an experiment was set up in which was tried to streamline all the relevant aspects of the interaction between the individual and its environment that occur in a rich sensory environment (where the contextual modalities were monitored). This research explicitly focuses on the idea that an Ambient Intelligence system can create scenarios that augment the possibilities of reaching a positive outcome taking into account the role of contextualized social relationships in various conflict management strategies.This work is part-funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT - Fundac¸ ˜ao para a Ciˆencia e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-028980 (PTDC/EEI-SII/1386/2012) and project PEst-OE/EEI/UI0752/2014

Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring

Nanomedications can be carried by blood borne monocyte-macrophages into the reticuloendothelial system (RES; spleen, liver, lymph nodes) and to end organs. The latter include the lung, RES, and brain and are operative during human immunodeficiency virus type one (HIV-1) infection. Macrophage entry into tissues is notable in areas of active HIV-1 replication and sites of inflammation. In order to assess the potential of macrophages as nanocarriers, superparamagnetic iron-oxide and/or drug laden particles coated with surfactants were parenterally injected into HIV-1 encephalitic mice. This was done to quantitatively assess particle and drug biodistribution. Magnetic resonance imaging (MRI) test results were validated by histological coregistration and enhanced image processing. End organ disease as typified by altered brain histology were assessed by MRI. The demonstration of robust migration of nanoformulations into areas of focal encephalitis provides '"proof of concept" for the use of advanced bioimaging techniques to monitor macrophage migration. Importantly, histopathological aberrations in brain correlate with bioimaging parameters making the general utility of MRI in studies of cell distribution in disease feasible. We posit that using such methods can provide a real time index of disease burden and therapeutic efficacy with translational potential to humans

Comparative manufacture and cell-based delivery of antiretroviral nanoformulations

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods. Interestingly, for drug cell targeting and antiretroviral responses the most significant difference among the particles was the drug itself. We posit that the choice of drug and formulation composition may ultimately affect clinical utility

A silent cry for leadership : organizing for leading (in) clusters

Leadership research so far has neglected clusters as a particular context for leadership, while research on networks and clusters has hardly studied leadership issues. This paper fills this dual gap in the abundant research on leadership on the one hand and on networks/clusters on the other by investigating leadership in photonics clusters from a structuration perspective. Apart from giving an insight into the variety and patterns of leadership practices observed, the paper addresses the dilemma that regional innovation systems such as clusters usually have a critical need of some kind of leadership, but that neither individual nor organizational actors wish to be led. This dilemma can only be ‘managed’ by organizing for leading (in) clusters in a certain way

Alternative approaches for studying shared and distributed leadership

Scholars hold different perspectives about leadership which are not limited to a formally appointed leader. Of the abundance of terms used to describe this phenomenon, shared and distributed are the most prevalent. These terms are often used interchangeably, resulting in confusion in the way that shared and distributed leadership is conceptualized and investigated. This paper provides a historical development of this field, challenges existing conceptions and reveals inconsistencies and contradictions that are seldom acknowledged. Four distinct approaches to the study of shared and distributed leadership are identified in the literature, each embracing different ontological views and leadership epistemologies. Individually, the four approaches offer valuable - yet partial - understanding. Comparing and contrasting the assumptions and insights from the four approaches raises fundamental issues about how we think about leadership in terms of research, practice and development

Long-acting antituberculous therapeutic nanoparticles target macrophage endosomes.

Eradication of Mycobacterium tuberculosis (MTB) infection requires daily administration of combinations of rifampin (RIF), isoniazid [isonicotinylhydrazine (INH)], pyrazinamide, and ethambutol, among other drug therapies. To facilitate and optimize MTB therapeutic selections, a mononuclear phagocyte (MP; monocyte, macrophage, and dendritic cell)-targeted drug delivery strategy was developed. Long-acting nanoformulations of RIF and an INH derivative, pentenyl-INH (INHP), were prepared, and their physicochemical properties were evaluated. This included the evaluation of MP particle uptake and retention, cell viability, and antimicrobial efficacy. Drug levels reached 6 μg/10(6) cells in human monocyte-derived macrophages (MDMs) for nanoparticle treatments compared with 0.1 μg/10(6) cells for native drugs. High RIF and INHP levels were retained in MDM for \u3e15 d following nanoparticle loading. Rapid loss of native drugs was observed in cells and culture fluids within 24 h. Antimicrobial activities were determined against Mycobacterium smegmatis (M. smegmatis). Coadministration of nanoformulated RIF and INHP provided a 6-fold increase in therapeutic efficacy compared with equivalent concentrations of native drugs. Notably, nanoformulated RIF and INHP were found to be localized in recycling and late MDM endosomal compartments. These were the same compartments that contained the pathogen. Our results demonstrate the potential of antimicrobial nanomedicines to simplify MTB drug regimens