Laura Bauer

Biological applications of high aspect ratio nanoparticles

This review describes recent advances in nanomaterials fabrication that have led to the synthesis of high aspect ratio particles on nanometer length scales. The elongated structure of these materials often result in inherent chemical, electrical, magnetic, and optical anisotropy that can be exploited for interactions with cells and biomolecules in fundamentally new ways. We briefly describe the synthetic procedures that have been developed to fabricate nanorods, nanowires, and nanotubes. We summarize literature reports that describe the use of high aspect ratio nanoparticles for biological sensing, separations, and gene delivery. We emphasize the recent discovery of single nanowire field-effect transistors that may revolutionize biological sensing and yield extremely low detection limits. Separations technology with chemically modifiable nanotube membranes and with magnetic nanowires that can be tailored to selectively interact with molecules of interest is also described. Other areas of biotechnology that have been improved by the integration of high aspect ratio nanoparticles are also described.

Magnetic trapping and self-assembly of multicomponent nanowires

Magnetic nanowires suspended in fluid solutions can be assembled and ordered by taking advantage of their large shape anisotropy. Magnetic manipulation and assembly techniques are demonstrated, using electrodeposited Ni nanowires, with diameter 350 nm and length 12 μm. Orienting suspended nanowires in a small magnetic field H≈10 G promotes self-assembly of continuous chains that can extend over several hundred μm. The dynamics of this process can be described quantitatively in terms of the interplay of magnetic forces and fluid drag at low Reynolds number. In addition, a new technique of magnetic trapping is described, by which a single magnetic nanowire can be captured between lithographically patterned magnetic microelectrodes. The use of three-segment Pt–Ni–Pt nanowires yields low resistance, Ohmic electrical contacts between the nanowires and the electrodes. This technique has potential for use in the fabrication and measurement of nanoscale magnetic devices.

Biological applications of multifunctional magnetic nanowires (invited)

Magnetic particles that can be bound to cells and biomolecules have become an important tool for the application of force in biology and biotechnology. Multifunctional magnetic nanowires fabricated by electrochemical deposition in nanoporous templates are a type of magnetic carrier that offers significant potential advantages over commercially available magnetic particles. Recent experimental work aimed at developing these wires for this purpose is reviewed. Results on chemical functionalization of Au and Au/Ni wires and magnetic manipulation of wires in suspension are described. Fluorescence microscopy was used to demonstrate the covalent binding of thiol-terminated porphyrins to Au nanowires, and to optimize functionalization of two-segment gold–nickel nanowires for selectivity and stability of the nanowire–molecule linkages. Magnetic trapping is a technique where single nanowires are captured from fluid suspension using lithographically patterned micromagnets. The influence of an external magnetic fiel...

The Society of Cardiovascular Anesthesiologists' FOCUS initiative: Locating Errors through Networked Surveillance (LENS) project vision.

Peter J. Pronovost, MD, PhD* BACKGROUND Although the methods to measure preventable harm are imprecise and immature, preventable harm is one of the leading causes of death, disability, and increased costs of care. The field of anesthesiology has been recognized for its efforts to improve patient safety, but much work remains to reduce harm to patients having cardiac surgery. Despite significant publicity regarding patient safety and efforts to improve it since the publication of To Err Is Human 10 years ago, there is little empiric evidence that health care is safer. For example, reports of wrong-site surgery continue to increase year after year despite a national patient safety goal* and widespread efforts intended to reduce such events. Although the true increase in wrong-site surgery is debated and may represent reporting bias, we clearly have not eliminated this sentinel event or other events for which there are data. One logically asks why a country that spends more than 2 trillion dollars a year on health care, 17% of its gross domestic product, continues to produce significant preventable harm. Why do wrong-site surgeries and other adverse events continue despite substantial efforts by regulators, hospitals, and professional societies? The problem is complex and implementing solutions has been exceedingly difficult. However, the solution is conceptually simple: we must adequately develop and apply rigorous science to analyzing errors in the delivery of health care. For example, despite there being a national policy to prevent wrong-site surgery, there are little to no data showing the effectiveness of this intervention. Few quick fixes will improve safety. Similar to biomedical science, safety improvements will require a robust and disciplined science that matures over time. Perhaps the greatest barrier to measurable progress in patient safety is the inability to evaluate with scientific rigor whether patient safety interventions are effective. This is the result of insufficient research funding and, paradoxically, the interdisciplinary nature of patient safety. There is sparse research funding for “basic science” in patient safety, especially to develop measures and tools to improve it. As a result, measures are often of poor quality, and the interventions of limited effectiveness, if not harmful. There are many disciplines that inform the science of patient safety, including organizational sociology and industrial psychology, clinical medicine, human factors engineering, health services research, economics, epidemiology, biostatistics, and informatics. Each discipline views the world through a unique “lens” and has a different frame of reference for viewing various aspects of patient safety risks and interventions as compared with others. Unfortunately, these lenses are From the *Departments of Anesthesiology & Critical Care Medicine and Pediatrics, The Johns Hopkins University School of Medicine and the †Department of Health Policy & Management, Bloomberg School of Public Health, Baltimore, Maryland. Accepted for publication October 5, 2009. Supported by the Society of Cardiovascular Anesthesiologists (SCA) Foundation for the LENS Project. Elizabeth A. Martinez was supported by the Agency for Healthcare Research and Quality K08 grant #HS013904-02. The FOCUS Initiative is a collaborative project of the Society of Cardiovascular Anesthesiologists, the SCA Foundation, and the Johns Hopkins University Quality and Safety Research Group. FOCUS is funded exclusively by the SCA Foundation. Address correspondence and reprint requests to Peter J. Pronovost, MD, PhD, The Johns Hopkins University School of Medicine, 1909 Thames St., Second Floor, Baltimore, MD 21231. Address e-mail to ppronovo@jhmi.edu. Copyright

Variation in local institutional review board evaluations of a multicenter patient safety study.

&NA; Several highly visible quality improvement (QI) projects led to controversy over their ethical oversight, attracting attention from institutional review boards (IRBs) and the Office for Human Research Protection. While QI research has increased dramatically, there is limited empirical evidence regarding how multiple IRBs review the same study. This paper describes the variations in local IRB reviews for the same a multicenter QI study. The study, entitled “Locating Errors through Networked Surveillance”, used multiple data collection methods to identify patient safety risks in cardiovascular operating room services. This study involved 2‐day site visits to 5 hospitals by the research team to observe cardiac surgery procedures and interview staff regarding clinical practice and hazards. Surveys were self‐administered. The IRB process varied widely across the 5 hospitals. Reviews ranged from full committee review and approval with verbal consent required from patients and operating room staff, to an IRB determining the study exempt from review and participant consent. The time to IRB approval ranged from 6 weeks to 6 months. This variation suggests there is wide interpretation of the Federal regulations put in place to guide IRBs. The adoption of uniformity would not only reduce inefficiencies but also attenuate the perceived arbitrary nature of current IRB review processes that often inappropriately influence hypothesis‐generation and study design.