In vivo biocompatibility evaluation of a new resilient, hard-carbon, thin-film coating for ventricular assist devices

Surface Coatings for Rotary Ventricular Assist Devices: A Systematic Review

Rotary ventricular assist devices (VADs) are frequently used to provide mechanical circulatory support to patients suffering from end-stage heart failure. Therefore, these devices and especially their pump impeller and housing components have stringent requirements on wear resistance and hemocompatibility. Various surface coatings have been investigated to improve the wear resistance or hemocompatibility of these devices. The aim of the present systematic review was to build a comprehensive understanding of these coatings and provide potential future research directions. A Boolean search for peer-reviewed studies was conducted in online databases (Web of Science, Scopus, PubMed, and ScienceDirect), and a preferred reporting items for systematic reviews and meta-analyses (PRISMA) process was followed for selecting relevant papers for analysis. A total of 45 of 527 publications were included for analysis. Eighteen coatings were reported to improve wear resistance or hemocompatibility of rotary VADs with the most common coatings being diamond-like carbon (DLC), 2-methacryloyloxyethyl phosphorylcholine (MPC), and heparin. Ninety-three percent of studies focused on hemocompatibility, whereas only 4% of studies focused on wear properties. Thirteen percent of studies investigated durability. This review provides readers with a systematic catalogue and critical review of surface coatings for rotary VADs. The review has identified that more comprehensive studies especially investigations on wear properties and durability are needed in future work.

The future of carbon-based scaffolds in foot and ankle surgery

Carbon may represent an alternative material suitable for future development as a soft-tissue substitute that potentially optimizes the biological and mechanical properties required for a graft product used in surgery. In addition, other modes of characterization such as 3-dimensional computational modeling may offer an insight into material performance in a biological environment. Further investigation is required to characterize and model the relationships between biological, mechanical, and design properties of this material to maximize its potential as a biomechanical scaffold and vehicle for delivering biologics that promote tissue repair and regeneration.

Formation of Nanocones on Highly Oriented Pyrolytic Graphite by Oxygen Plasma

Improvement in hemocompatibility of highly oriented pyrolytic graphite (HOPG) by formation of nanostructured surface by oxygen plasma treatment is reported. We have showed that by appropriate fine tuning of plasma and discharge parameters we are able to create nanostructured surface which is densely covered with nanocones. The size of the nanocones strongly depended on treatment time. The optimal results in terms of material hemocompatibility were obtained after treatment with oxygen plasma for 15 s, when both the nanotopography and wettability were the most favorable, since marked reduction in adhesion and activation of platelets was observed on this surface. At prolonged treatment times, the rich surface topography was lost and thus also its antithrombogenic properties. Chemical composition of the surface was always more or less the same, regardless of its morphology and height of the nanocones. Namely, on all plasma treated samples, only a few atomic percent of oxygen was found, meaning that plasma caused mostly etching, leading to changes in the surface morphology. This indicates that the main preventing mechanism against platelets adhesion was the right surface morphology.

Hybrid carbon-based scaffolds for applications in soft tissue reconstruction

Current biomedical scaffolds utilized in surgery to repair soft tissues commonly fail to meet the optimal combination of biomechanical and tissue regenerative properties. Carbon is a scaffold alternative that potentially optimizes the balance between mechanical strength, durability, and function as a cell and biologics delivery vehicle that is necessary to restore tissue function while promoting tissue repair. The goals of this study were to investigate the feasibility of fabricating hybrid fibrous carbon scaffolds modified with biopolymer, polycaprolactone and to analyze their mechanical properties and ability to support cell growth and proliferation. Environmental scanning electron microscopy, micro-computed tomography, and cell adhesion and cell proliferation studies were utilized to test scaffold suitability as a cell delivery vehicle. Mechanical properties were tested to examine load failure and elastic modulus. Results were compared to an acellular dermal matrix scaffold control (GraftJacket(®) [GJ] Matrix), selected for its common use in surgery for the repair of soft tissues. Results indicated that carbon scaffolds exhibited similar mechanical maximums and capacity to support fibroblast adhesion and proliferation in comparison with GJ. Fibroblast adhesion and proliferation was collinear with carbon fiber orientation in regions of sparsely distributed fibers and occurred in clusters in regions of higher fiber density and low porosity. Overall, fibroblast adhesion and proliferation was greatest in lower porosity carbon scaffolds with highly aligned fibers. Stepwise multivariate regression showed that the variability in maximum load of carbon scaffolds and controls were dependent on unique and separate sets of parameters. These finding suggested that there were significant differences in the functional implications of scaffold design and material properties between carbon and dermis derived scaffolds that affect scaffold utility as a tissue replacement construct.

The future of adult cardiac assist devices: novel systems and mechanical circulatory support strategies

The recent, widespread success of mechanical circulatory support has prompted the development of numerous implantable devices to treat advanced heart failure. It is important to raise awareness of novel device systems, the mechanisms by which they function, and implications for patient management. This article discusses devices that are being developed or are in clinical trials. Devices are categorized as standard full support, less-invasive full support, partial support: rotary pumps, partial support: counterpulsation devices, right ventricular assist device, and total artificial heart. Implantation strategy, mechanism of action, durability, efficacy, hemocompatibility, and human factors are considered. The feasibility of novel strategies for unloading the failing heart is examined.

Artificial organs 2010: a year in review

In this Editor's Review, articles published in 2010 are organized by category and briefly summarized. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, and the International Society for Rotary Blood Pumps, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level."Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide such meaningful suggestions to the author's work whether eventually accepted or rejected and especially to those whose native tongue is not English. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, Wiley-Blackwell, for their expert attention and support in the production and marketing of Artificial Organs. In this Editor's Review, that historically has been widely received by our readership, we aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. We look forward to recording further advances in the coming years.