Microencapsulation Technologies for Corrosion Protective Coating Applications

Microencapsulation technologies for functional smart Coatings for autonomous corrosion control have been a research area of strong emphasis during the last decade. This work concerns the development of pH sensitive micro-containers (microparticles and microcapsules) for autonomous corrosion control. This paper presents an overview of the state-of-the-art in the field of microencapsulation for corrosion control applications, as well as the technical details of the pH sensitive microcontainer approach, such as selection criteria for corrosion indicators and corrosion inhibitors; the development and optimization of encapsulation methods; function evaluation before and after incorporation of the microcontainers into coatings; and further optimization to improve coating compatibility and performance

Microfluidics for Advanced Drug Delivery Systems.

Considerable efforts have been devoted towards developing effective drug delivery methods. Microfluidic systems, with their capability for precise handling and transport of small liquid quantities, have emerged as a promising platform for designing advanced drug delivery systems. Thus, microfluidic systems have been increasingly used for fabrication of drug carriers or direct drug delivery to a targeted tissue. In this review, the recent advances in these areas are critically reviewed and the shortcomings and opportunities are discussed. In addition, we highlight the efforts towards developing smart drug delivery platforms with integrated sensing and drug delivery components

Nanotechnological Strategies for Protein Delivery

The use of therapeutic proteins plays a fundamental role in the treatment of numerous diseases. The low physico-chemical stability of proteins in physiological conditions put their function at risk in the human body until they reach their target. Moreover, several proteins are unable to cross the cell membrane. All these facts strongly hinder their therapeutic effect. Nanomedicine has emerged as a powerful tool which can provide solutions to solve these limitations and improve the efficacy of treatments based on protein administration. This review discusses the advantages and limitations of different types of strategies employed for protein delivery, such as PEGylation, transport within liposomes or inorganic nanoparticles or their in situ encapsulation

Release from polyelectrolyte multilayer capsules in solution and on polymeric surfaces

Release from polyelectrolyte multilayer microcapsules represents one of the most important steps enabling practical use of the microcapsules. A number of biological and non-biological applications are envisaged by proper encapsulation of molecules of interest and their release performance. Since the invention of the microcapsules at the Max-Planck Institute of Colloids and Interfaces in 1998 the work towards microcapsule assistant release has undergone tremendous progress. Almost simultaneously with development of release approaches an extensive base of applications has been advanced. In this progress report the release from the capsules in a solution and those immobilized on the surface of polymeric films is addressed

Ideal material properties for capsules or vascular sustem used in cementitious self-healing materials

Self-healing in cementitious materials, i.e. concrete, has a huge potential towards reducing maintenance and repair costs and increasing the service life of concrete structures. The biggest advantage of self-healing concrete is that small cracks, who provide access to hazardous gasses and liquids, are healed and structural degradation is prevented. Several techniques are trending in the field of self-healing concrete, self-healing using bacteria, self-healing using a vascular system and self-healing using capsules. Focusing on the two latter, an encapsulation material is needed. This paper describes the ideal properties of such an encapsulation material, taking into account as many steps of the life-cycle of the self-healing concrete, i.e. from production until the end of the structure. Such an ideal encapsulation material should be resistant through time to the healing-agent as well as to the cementitious environment. The ideal material should be brittle enough to rupture upon cracking of the (aged) concrete on one hand, and on the other it should be strong enough to survive the concrete mixing and casting process. The properties are not always to be combined by one and the same material, combinations of materials who take up different requirements are possible. In current research glass is most often used as encapsulation material. It’s a brittle material which is able to contain the healing agent, but it also suffers from a slow chemical interaction with the alkali-environment, and a very low survival rate when implemented in realistic industrial concrete casting processes. The goal of this study is to investigate the wanted versus the needed properties in order to select other materials than glass or to select other materials to combine with glass

Synthetic micro/nanomotors in drug delivery

Nanomachines offer considerable promise for the treatment of diseases. The ability of man-made nanomotors to rapidly deliver therapeutic payloads to their target destination represents a novel nanomedicine approach. Synthetic nanomotors, based on a multitude of propulsion mechanisms, have been developed over the past decade toward diverse biomedical applications. In this review article, we journey from the use of chemically powered drug-delivery nanovehicles to externally actuated (fuel-free) drug-delivery nanomachine platforms, and conclude with future prospects and challenges for such practical propelling drug-delivery systems. As future micro/nanomachines become more powerful and functional, these tiny devices are expected to perform more demanding biomedical tasks and benefit different drug delivery applications

Turning Erythrocytes into Functional Micromotors

Attempts to apply artificial nano/micromotors for diverse biomedical applications have inspired a variety of strategies for designing motors with diverse propulsion mechanisms and functions. However, existing artificial motors are made exclusively of synthetic materials, which are subject to serious immune attack and clearance upon entering the bloodstream. Herein we report an elegant approach that turns natural red blood cells (RBCs) into functional micromotors with the aid of ultrasound propulsion and magnetic guidance. Iron oxide nanoparticles are loaded into the RBCs, where their asymmetric distribution within the cells results in a net magnetization, thus enabling magnetic alignment and guidance under acoustic propulsion. The RBC motors display efficient guided and prolonged propulsion in various biological fluids, including undiluted whole blood. The stability and functionality of the RBC motors, as well as the tolerability of regular RBCs to the ultrasound operation, are carefully examined. Since the RBC motors preserve the biological and structural features of regular RBCs, these motors possess a wide range of antigenic, transport, and mechanical properties that common synthetic motors cannot achieve and thus hold considerable promise for a number of practical biomedical uses

Fluorescent carbon dioxide indicators

Over the last decade, fluorescence has become the dominant tool in biotechnology and medical imaging. These exciting advances have been underpinned by the advances in time-resolved techniques and instrumentation, probe design, chemical / biochemical sensing, coupled with our furthered knowledge in biology. Complementary volumes 9 and 10, Advanced Concepts of Fluorescence Sensing: Small Molecule Sensing and Advanced Concepts of Fluorescence Sensing: Macromolecular Sensing, aim to summarize the current state of the art in fluorescent sensing. For this reason, Drs. Geddes and Lakowicz have invited chapters, encompassing a broad range of fluorescence sensing techniques. Some chapters deal with small molecule sensors, such as for anions, cations, and CO2, while others summarize recent advances in protein-based and macromolecular sensors. The Editors have, however, not included DNA or RNA based sensing in this volume, as this were reviewed in Volume 7 and is to be the subject of a more detailed volume in the near future

Layered Fabrication of Branched Networks Using Lindenmayer Systems

A current challenge impeding the growth of bone tissue engineering is the lack of functional scaffolds of geometric sizes greater than 10mm due to the inability of cells to survive deep within the scaffold. It is hypothesized that these scaffolds must have an inbuilt nutrient distribution network to sustain the uniform growth of cells. In this paper, we seek to enhance the design and layered fabrication of scaffold internal architecture through the development of Lindenmayer systems, a graphical language based theory to create nutrient delivery networks. The scaffolds are fabricated using the Texas Instruments DLP™ system through UV‐photopolymerization to produce polyethylene glycol hydrogels with internal branch structures. The paper will discuss the Lindenmayer system, process planning algorithms, layered fabrication of samples, challenges and future tasks.Mechanical Engineerin