Multifunctional magnetically loaded polyorganosiloxane nanocomposites for biomedical applications

For the last few decades, the interest in functional nanomaterials is steadily increasing. Especially, in biomedicine the range of possible applications of multifunctional nanoparticles including dye-labeled makers and drug loaded carrier systems is extraordinary large. The incorporation of magnetic nanoparticles allows for an additional magnetic detection and manipulation. One promising system on the way to multifunctional nanomaterials is the polyorganosiloxane system. Via polycondensation of silan monomers in aqueous dispersion polyorganosiloxane nanoparticles with particle diameter between 10 and 150 nm can be synthesized. The versatile silane chemistry allows for the design of multifunctional network structures. In this work, hydrophilic iron oxide nanoparticles could be encapsulated into the polymeric particles in a highly efficient process whereat the superparamagnetic nature of the inorganic particles was restrained. The influence of different sized particles as well as the amount of the incorporated material was investigated. Using a core-shell architecture, controlled core and surface modifications could be achieved. An effective fluorescent labeling was performed via incorporation of dye-labeled monomers. Additionally, a hydrophilic surface modification was carried out via a grafting onto process of poly(ethylene glycol). Individual core and surface functionalization was achieved and the influence of the modification on the efficiency of the magnetic loading was tested. The applicability of the multifunctional particles in biological systems was proved via cellular uptake and toxicity testings. Furthermore, biofunctionalized particles were synthesized by EDC coupling using biotin and insulin.rnrnWährend der letzten Jahrzehnte haben funktionelle Nanopartikel zunehmend wissenschaftliches Interesse geweckt. Besonders in biomedizinischen Anwendungen finden multifunktionelle polymere Materialien vielseitige Einsatzmöglichkeiten beispielsweise als farbstofffunktionalisierte Marker oder wirkstoffbeladene Transportsysteme. Der Einbau magnetischer Nanopartikel ermöglicht zusätzlich eine magnetische Detektion und Manipulation. Ein vielversprechendes System auf dem Weg zu multifunktionellen Nanopartikeln stellen Polyorganosiloxan Partikel dar. Durch Polykondensation von Silanmonomeren in wässriger Dispersion können Polyorgansiloxan Nanopartikel im Größenbereich von 10 bis 150 nm im Durchmesser hergestellt werden. Die vielseitige Silanchemie ermöglicht den Aufbau multifunktioneller Netzwerksysteme. In der vorliegenden Arbeit, konnten hydrophile Eisenoxidnanopartikel effizient und unter Erhalt ihrer superparamagnetischen Eigenschaften in die Polymerpartikel eingebaut werden. Der Einfluss verschiedener Partikelgrößen sowie verschiedener Eisenoxidgehalte wurde untersucht. Durch den Aufbau einer Kern-Schale-Architektur konnte eine gezielte Modifizierung des Partikelinneren und der Partikeloberfläche erreicht werden. Durch den Einbau fluoreszenzmodifizierter Monomere konnte eine Farbstoffmarkierung des Partikelkerns erzielt werden. Zusätzlich wurde eine hydrophile Oberflächenmodifizierung mittels Polyethlenoxid durchgeführt. Die Funktionalisierungen wurden unabhängig voneinander sowie in Kombination durchgeführt und der Einfluss der Funktionalisierung auf die Effizienz der magnetischen Beladung untersucht. Die Anwendbarkeit der synthetisierten Partikel in biomedizinischen Anwendungen wurde mit Hilfe von Zellaufnahme und Toxizitätstests nachgewiesen. Des Weiteren wurden biofunktionalisierte Partikel mittels EDC-Kopplung mit Biotin und Insulin hergestellt

Claudins in intestines

Intestines are organs that not only digest food and absorb nutrients, but also provide a defense barrier against pathogens and noxious agents ingested. Tight junctions (TJs) are the most apical component of the junctional complex, providing one form of cell-cell adhesion in enterocytes and playing a critical role in regulating paracellular barrier permeability. Alteration of TJs leads to a number of pathophysiological diseases causing malabsorption of nutrition and intestinal structure disruption, which may even contribute to systemic organ failure. Claudins are the major structural and functional components of TJs with at least 24 members in mammals. Claudins have distinct charge-selectivity, either by tightening the paracellular pathway or functioning as paracellular channels, regulating ions and small molecules passing through the paracellular pathway. In this review, we have discussed the functions of claudin family members, their distribution and localization in the intestinal tract of mammals, their alterations in intestine-related diseases and chemicals/agents that regulate the expression and localization of claudins as well as the intestinal permeability, which provide a therapeutic view for treating intestinal diseases

The History and Use of the Galesburg Rule in American Lutheranism

It is not the aim of this presentation to consider all the ecumenical issues and endeavors these three branches involved themselves in during the years 1875 to the present. Rather, this discussion is limited to only those personalities, documents, and events which had a direct relationship to The Galesburg Rule and the kind of ecclesiastical practice it encouraged. In addition to the standard American Lutheran histories, the primary source materials employed are the official convention proceedings and reports of the various synods and ministeriums under consideration. Also utilized are sources of secondary importance, such as the writings of the theological and ecclesiastical leaders from the synods noted above, as well as other pertinent material gleaned from certain independent theological publications of a scholarly nature

"Certainly the Proper Business of Woman": Household and Estate Management Techniques of Eighteenth-Century French Noblewomen

This project explores the legal, economic, and social aspects of household and estate management in eighteenth-century France. It investigates two paradoxes surrounding noblewomen and household management. The first involves society's view of women's appropriate social, economic, and legal activities. The second centers on women's preparation for household and estate management. Using manuscript sources from noblewomen and their household advisors, as well as official notarial documentation, this study charts how, through household and estate management, women contributed to the social, economic, and legal landscapes of France in the eighteenth century. In addition, it examines the role of household advisors, such as notaries, lawyers, and experienced members of the domestic staff, in helping women overcome their educational and experiential deficiencies when they assumed responsibility for estates and households. Current historiography on eighteenth-century French nobility tends to normalize the experiences of men, implying either that women's experiences conformed to those of their male counterparts, or that exploring the lives of noblewomen does not reveal much about society. This project addresses this issue by detailing the unique social and economic contributions of women as household and estate managers

Life History of Provost Beth Cada, Ed.D., OTR/L, FAOTA

The life history of Provost Beth Cada was one of 9 life history interview which are a part of a larger project of Life Histories of Individuals Who Have Been Influential in Developing Occupational Therapy (OT) in North Dakota and Wyoming. The purpose of the project is to obtain information about the history and evolution of OT practice in North Dakota and Wyoming. This study intends to provide current and future generations of occupational therapists a view of the history and how OT practice has evolved. The life history of Beth Cada is a case study that examined her life as a leader, OT practitioner, educator, and state representative. Throughout the study, the Kawa model was used to symbolize a river about the individual and their personal life history(Turpin & Iwama, 2011).https://commons.und.edu/ot-oral-histories-posters/1060/thumbnail.jp

Evolution of Occupational Therapy Practice: Life History of Beth Cada EdD., OTR/L, FAOTA

The purpose of this life history study was to gain an understanding and provide current and future generations of occupational therapists a view of the evolutionary history from its inception to current practice through the life history story of Beth Cada, EdD., OTR/L, FAOTA within the profession of occupational therapy. The occupational therapy students completed one 2-hour online interview using a semi-structured interview to learn about her personal and professional goals, education, leadership skills, and her role at a national level. Data was analyzed through coding of the transcribed interview. Four categories emerged from the interview process: professional roles, occupational therapy services, Dr. Cada’s client factors, and perceptions of occupational therapy practice. The results of this study found that Dr. Cada is a timeless advocate for all involved within the field of occupational therapy, including consumers, practitioners, and students. She is continuously active through leadership roles while mentoring others and providing occupational therapy practice to clients

Immersive Virtual Reality (VR) and Telehealth to Promote Engagement in Occupations for Rural Populations: Manual for Occupational Therapists

Abstract Telehealth has been used to alleviate the impact of occupational deprivation in rural communities (American Occupational Therapy Association [AOTA], 2018). There is continuing research on the development of telehealth in the occupational therapy profession. An emerging type of technology utilized in occupational therapy consists of using immersive VR interventions to increase client\u27s performance skills (Karamians, Proffitt, Kline & Gauthier, 2019; Kwan, Park, Yoon & Park, 2012; Halton, 2008; Weiss Rand, Katz & Kizony, 2004). The combination of immersive VR and telehealth allows occupational therapy practitioners to interact, evaluate, and intervene with clients living in rural communities. The immersive VR system encourages engagement in occupations by rehabilitation of the client\u27s performance skills and provides opportunities for the client and practitioner to work with one another to achieve tasks within the client\u27s virtual context. Using telehealth and immersive VR allows the practitioner to engage with the client in both the virtual context and the client\u27s natural context. Dunn, Brown and McGuigan (1994) and Turpin & Iwama (2011) explain that occupational performance cannot be fully understood outside of the natural context. A therapeutic manual has been developed which uses the Oculus Quest© immersive VR system, created by Facebook Technologies LLC. The Oculus Quest© interventions will be delivered using telehealth for clients living in rural communities. The manual provides occupational therapy practitioners with information needed to utilize immersive VR and telehealth during the therapy process in the client\u27s natural environment. The manual is intended for the occupational therapy practitioners interested in adding immersive VR technology to their rural practice. Practical information and considerations for effective use of immersive VR technology are included in the manual

Endocytosis and Recycling of Tight Junction Proteins in Inflammation

A critical function of the epithelial lining is to form a barrier that separates luminal contents from the underlying interstitium. This barrier function is primarily regulated by the apical junctional complex (AJC) consisting of tight junctions (TJs) and adherens junctions (AJs) and is compromised under inflammatory conditions. In intestinal epithelial cells, proinflammatory cytokines, for example, interferon-gamma (IFN-γ), induce internalization of TJ proteins by endocytosis. Endocytosed TJ proteins are passed into early and recycling endosomes, suggesting the involvement of recycling of internalized TJ proteins. This review summarizes mechanisms by which TJ proteins under inflammatory conditions are internalized in intestinal epithelial cells and point out comparable mechanism in nonintestinal epithelial cells

Polymeric Coatings for AR-Glass Fibers in Cement-Based Matrices: Effect of Nanoclay on the Fiber-Matrix Interaction

Polymeric coatings are widely used to enhance the load bearing capacity and chemical durability of alkali-resistant glass (AR-glass) textile in cement-based composites. The contact zone between coated yarns and concrete matrix plays a major role to enable the stress transfer and has still to be improved for the full exploitation of the mechanical behavior of the composite. As a new approach, this paper studies how the addition of nanoclay particles in the polymer coating formulation can increase the chemical bond between organic coating and inorganic matrix. This includes the description of the water-based coating preparation by dispersing sodium montmorillonites, whereby the resulting coating nanostructure is characterized by X-ray diffraction and energy dispersive X-ray spectroscopy. Single glass fibers were treated by dip-coating. Atomic force microscopy was used to determine the surface roughness, and the effect on the fiber tensile properties was studied. Moreover, the morphological and chemical characteristics of the coatings were compared with the results obtained from single fiber pull-out (SFPO) tests. It was shown that the incorporation of nanoclays leads to increased interfacial shear strength arising from the ability of nanoclay particles to nucleate hydration products in the fiber-matrix contact zone