Molecular Imaging of Brain Tumors Using Liposomal Contrast Agents and Nanoparticles

The first generation of cross-sectional brain imaging using computed tomography (CT), ultrasonography, and eventually MR imaging focused on determining structural or anatomic changes associated with brain disorders. The current state-of-the-art imaging, functional imaging, uses techniques such as CT and MR perfusion that allow determination of physiologic parameters in vivo. In parallel, tissue-based genomic, transcriptomic, and proteomic profiling of brain tumors has created several novel and exciting possibilities for molecular targeting of brain tumors. The next generation of imaging translates these molecular in vitro techniques to in vivo, noninvasive, targeted reconstruction of tumors and their microenvironments.

A Bosphorus submarine passage and the reinvention of neurosurgery

One of the major themes characterizing the emergence of modern neurosurgery has been the concept of technology transfer and the application of a broad spectrum of revolutionary elements of technology from both physical and biological science. These transference applications are now apparent in modern neurosurgery as it is practiced on all continents of the globe. More than 3 decades ago, these ideas that now have come to fruition were in states of formulation. This article describes and further documents one such fertile cauldron of ideas and practical realities--the United States Navy Nuclear Submarine Service and its role and affect on the life and professional career of an academic neurosurgeon who was active in areas of progress as modernity was established for the early 21st century.

Neurosurgery and quantum dots: part I--state of the art

This article represents the first of a 2-part exploration of quantum dots (Qdots) and their application to neurological surgery. Spanning from materials science to immunology, this initial review traces the marriage of imaging physics to biochemical specificity. Qdot science now stands poised to dramatically advance the diagnosis and therapy of neurosurgical conditions. Qdot research efforts currently involve several disciplines; this comprehensive review therefore considers multiple fields of inquiry. This first installment discusses 1) Qdot physical properties, 2) established biological and in vivo properties, 3) magnetic resonance imaging applications, and (4) existing cardiovascular and oncologic research. Finally, this review establishes the existing bounds of Qdot possibilities. The second concept article details future endovascular diagnostic and therapeutic methods derived from these seminal advances.

In vitro characterization of a targeted, dye-loaded nanodevice for intraoperative tumor delineation

OBJECTIVE

To synthesize and complete in vitro characterization of a novel, tumor-targeted nanodevice for visible intraoperative delineation of brain tumors.

METHODS

The ability of dye-loaded polyacrylamide nanoparticles (NP) containing methylene blue, Coomassie blue, or indocyanine green to cause color change in the 9L glioma cell lines was evaluated. Cells were incubated with dye-loaded NPs, photographed, and analyzed colorimetrically. Confocal microscopy was used to determine subcellular localization of NPs in treated cells.

RESULTS

Incubation of glioma cell lines with dye-loaded NPs resulted in clearly visible, quantifiable cell tagging in a dose- and time-dependent manner. Dye-loaded NPs were observed to bind to the surface and become internalized by glioma cells. Coating the NP surface with F3, a peptide that binds to the tumor cell surface receptor nucleolin, significantly increased NP affinity for glioma cells. F3 targeting also significantly increased the rate of cell tagging by dye-loaded NPs. Finally, F3-targeted NPs demonstrated specificity for targeting various cancer cell lines based on their surface expression of cell surface nucleolin.

CONCLUSION

F3-targeted dye-loaded NPs efficiently cause definitive color change in glioma cells. This report represents the first use of targeted NPs to cause a visible color change in tumor cell lines. Similar nanodevices may be used in the future to enable visible intraoperative tumor delineation during tumor resection.

The alchemy of ideas

This article presents an assessment of the power of ideas and their role in initiating change and progress. The enormous potential cascade effect is illustrated by examining the movement of Modernism in the arts. Next, the immense scope and capabilities of the modern scientific endeavor-with robotic space exploration at the scale of 10 meters at one extreme and the wonders of nanoscience at the scale of 10 m at the other-are examined. The attitudes and philosophies of neurological surgery are related to those involved in the Modernist movement and placed on the defined scale of contemporary scientific activity.

Neurosurgery in the realm of 10(-9), part 1: stardust and nanotechnology in neuroscience

Nanotechnology as a science has evolved from notions and speculation to emerge as a prominent combination of science and engineering that stands to impact innumerable aspects of technology. Medicine in general and neurosurgery in particular will benefit greatly in terms of improved diagnostic and therapeutic capabilities. The recent explosion in nanotechnology products, including diverse applications such as beauty products and medical contrast agents, has been accompanied by an ever increasing volume of literature. Recent articles from our institution provided an historical and scientific background of nanotechnology, with a purposeful focus on nanomedicine. Future applications of nanotechnology to neuroscience and neurosurgery were briefly addressed. The present article is the first of two that will further this discussion by providing specific details of current nanotechnology applications and research related to neuroscience and clinical neurosurgery. This article also provides relevant perspective in scale, history, economics, and toxicology. Topics of specific importance to developments or advances of technologies used by neuroscientists and neurosurgeons are presented. In addition, advances in the field of microelectromechanical systems technology are discussed. Although larger than nanoscale, microelectromechanical systems technologies will play an important role in the future of medicine and neurosurgery. The second article will discuss current nanotechnologies that are being, or will be in the near future, incorporated into the armamentarium of the neurosurgeon. The goal of these articles is to keep the neuroscience community abreast of current developments in nanotechnology, nanomedicine, and, in particular, nanoneurosurgery, and to present possibilities for future applications of nanotechnology. As applications of nanotechnology permeate all forms of scientific and medical research, clinical applications will continue to emerge. Physicians of the present and future must take an active role in shaping the design and research of nanotechnologies to ensure maximal clinical relevance and patient benefit.

In vivo use of a nanoknife for axon microsurgery

OBJECTIVE

Microfabricated devices with nanoscale features have been proposed as new microinstrumentation for cellular and subcellular surgical procedures, but their effectiveness in vivo has yet to be demonstrated. In this study, we examined the in vivo use of 10 to 100 microm-long nanoknives with cutting edges of 20 nm in radius of curvature during peripheral nerve surgery.

METHODS

Peripheral nerves from anesthetized mice were isolated on a rudimentary microplatform with stimulation microelectrodes, and the nanoknives were positioned by a standard micromanipulator. The surgical field was viewed through a research microscope system with brightfield and fluorescence capabilities.

RESULTS

Using this assembly, the nanoknife effectively made small, 50 to 100 microm-long incisions in nerve tissue in vivo. This microfabricated device was also robust enough to make repeated incisions to progressively pare down the nerve as documented visually and by the accompanying incremental diminution of evoked motor responses recorded from target muscle. Furthermore, this nanoknife also enabled the surgeon to perform procedures at an unprecedented small scale such as the cutting and isolation of a small segment from a single constituent axon in a peripheral nerve in vivo. Lastly, the nanoknife material (silicon nitride) did not elicit any acute neurotoxicity as evidenced by the robust growth of axons and neurons on this material in vitro.

CONCLUSION

Together, these demonstrations support the concept that microdevices deployed in a neurosurgical environment in vivo can enable novel procedures at an unprecedented small scale. These devices are potentially the vanguard of a new family of microscale instrumentation that can extend surgical procedures down to the cellular scale and beyond.

Upstream ethics in nanomedicine: a call for research

Insufficient attention has been given to ethical and social issues integral to nanomedicine. Part of this deficiency arises from some mistaken assumptions about ethics. I consider five of these: that ethics is only important when a technology is mature (reactionary ethics); that there are no new ethical issues in nanomedicine; that ethics involves a kind of risk assessment that is already being conducted; that ethics is a hindrance to science; and that ethics is a luxury for an ideal world. After critically assessing these assumptions, I consider two types of nanomedicine and the kinds of ethical issues they raise. Type 1 nanomedicine is of an incremental kind, and proper ethical assessment of the issues must involve a fine grained study of the specific application. Type 2 nanomedicine is of a more foundational, programmatic kind. Ethical issues raised by these more programmatic developments include challenges integral to formation of interdisciplinary teams; issues related to intellectual property, authorship and publication; development of informed consent and confidentiality protections associated with new data sets; future challenges to the clinician–patient relation and personalized medicine. Ethical analysis should also consider some of the reductionistic implications of engineering models and metaphors integral to nanomedicine, as well as uses of nanomedicine for non-medical purposes, such as human enhancement. Many of these challenges concern rate-limiting steps in nanomedical research, and they should be prominently featured in developing nanomedicine initiatives.

Challenges for Australia's Bio/Nanopharma Policies: trade deals, public goods and reference pricing in sustainable industrial renewal

Industrial renewal in the bio/nanopharma sector is important for the long term strength of the Australian economy and for the health of its citizens. A variety of factors, however, may have caused inadequate attention to focus on systematically promoting domestic generic and small biotechnology manufacturers in Australian health policy. Despite recent clarifications of 'springboarding' capacity in intellectual property legislation, federal government requirements for specific generic price reductions on market entry and the potential erosion of reference pricing through new F1 and F2 categories for the purposes of Pharmaceutical Benefits Scheme (PBS) assessments, do not appear to be coherently designed to sustainably position this industry sector in 'biologics,' nanotherapeutics and pharmacogenetics. There also appears to have been little attention paid in this context to policies fostering industry sustainability and public affordability (as encouraged by the National Medicines Policy). One notable example includes that failure to consider facilitating mutual exchanges on regulatory assessment of health technology safety and cost-effectiveness (including reference pricing) in the context of ongoing free trade negotiations between Australia and China (the latter soon to possess the world's largest generic pharmaceutical manufacturing capacity). The importance of a thriving Australian domestic generic pharmaceutical and bio/nano tech industry in terms of biosecurity, similarly appears to have been given insufficient policy attention.Reasons for such policy oversights may relate to increasing interrelationships between generic and 'brand-name' manufacturers and the scale of investment required for the Australian generics and bio/nano technology sector to be a significant driver of local production. It might also result from singularly effective lobbying pressure exerted by Medicines Australia, the 'brand-name' pharmaceutical industry association, utilising controversial interpretations of reward of pharmaceutical 'innovation' provisions in the Australia-US Free Trade Agreement (AUSFTA) through the policy-development mechanisms of the AUSFTA Medicines Working Group and most recently an Innovative Medicines Working Group with the Department of Health and Ageing. This paper critically analyses such arguments in the context of emerging challenges for sustainable industrial renewal in Australia's bio/nanopharma sector.

Stereotactic Radiosurgery: Adjacent Tissue Injury and Response after High-Dose Single Fraction Radiation—Part II: Strategies for Therapeutic Enhancement, Brain Injury Mitigation, and Brain Injury Repair

IN THE FIRST part of this series, we reviewed the histological, radiographic, and molecular data gathered regarding the brain parenchymal response to radiosurgery and suggested future studies that could enhance our understanding of the topic. With this article, we begin by addressing methods of potentiating the effect of radiosurgery on target lesions of the central nervous system. Much of the work on potentiating the effects of cranial radiation has been performed in the field of whole-brain radiotherapy. Data from Phase III trials evaluating the efficacy of various agents as radiosensitizers or radioenhancers in whole-brain radiotherapy are reviewed, and trials for investigating certain agents as enhancers of radiosurgery are suggested. The roles of gene therapy and nanotechnology in enhancing the therapeutic efficacy of radiosurgery are then addressed. Focus is then shifted to a discussion of strategies of protecting healthy tissue from the potentially deleterious aspects of the brain's response to radiosurgery that were presented in the first article of this series. Finally, comments are made regarding the role of neural progenitor or stem cells in the repair of radiation-induced brain injury after radiosurgery. The importance of both the role of the extracellular matrix and properly directed axonal regrowth leading to appropriate target reinnervation is highlighted.

Nanotechnology in global medicine and human biosecurity: private interests, policy dilemmas, and the calibration of public health law

This paper considers how best to approach dilemmas posed to global health and biosecurity policy by increasing advances in practical applications of nanotechnology. The type of nano-technology policy dilemmas discussed include: (1) expenditure of public funds, (2) public-funded research priorities, (3) public confidence in government and science and, finally, (4) public safety. The article examines the value in this context of a legal obligation that the development of relevant public health law be calibrated against less corporate-influenced norms issuing from bioethics and international human rights.

Policy challenges from the "White" Senate inquiry into workplace-related health impacts of toxic dusts and nanoparticles

On 22 June 2005 the Senate of the Commonwealth of Australia voted to establish an inquiry into workplace harm related to toxic dust and emerging technologies (including nanoparticles). The inquiry became known as the "White" Inquiry after Mr Richard White, a financially uncompensated sufferer of industrial sandblasting-induced lung disease who was instrumental in its establishment. The "White" Inquiry delivered its final report and recommendations on 31 May 2006. This paper examines whether these recommendations and their implementation may provide a unique opportunity not only to modernize relevant monitoring standards and processes, but related compensation systems for disease associated with workplace-related exposure to toxic dusts. It critically analyzes the likely role of the new Australian Safety and Compensation Council (ASCC) in this area. It also considers whether recommendations related to potential workplace related harm from exposure to nanoparticles could commence a major shift in Australian healthcare regulation.

Toward the Emergence of Nanoneurosurgery: Part III—Nanomedicine: Targeted Nanotherapy, Nanosurgery, and Progress Toward the Realization of Nanoneurosurgery

The notion of nanotechnology has evolved since its inception as a fantastic conceptual idea to its current position as a mainstream research initiative with broad applications among all divisions of science. In the first part of this series, we reviewed the structures and principles that comprise the main body of knowledge of nanoscience and nanotechnology. In the second part, we discussed applications of nanotechnology to the emerging field of nanomedicine, with specific attention on medical diagnostics and imaging. This article further explores the applications of nanotechnology to nanomedicine. Specific attention is given to developments in therapeutic modalities, including advanced drug delivery systems and targeted nanotherapy, which will form the basis for the treatment arm of mature nanomedicine. A variety of modalities are discussed, including polymeric nanoparticles, micelles, liposomes, dendrimers, fullerenes, hydrogels, nanoshells, and smart surfaces. Applications of nanotechnology to nanosurgery and nanoneurosurgery are presented. Femtosecond laser systems, nanoneedles, and nanotweezers are presented as technologies that are operational at the nanoscale level and have the potential to revolutionize the practice of neurosurgery in a profound and momentous way.

Surgical insights into Parkinson's disease

Surgery for Parkinson's disease was popularized in the mid-twentieth century before the advent of effective medical therapies. Early lesioning treatments contributed to our understanding of the functional anatomy of Parkinson's disease. Observations of the limitations and long-term complications of established pharmacological therapies for Parkinson's disease, together with major contributions from animal research to elucidate the roles of the basal ganglia in movement disorders, inspired a recent renaissance in neurosurgical interventions for Parkinson's disease including deep brain stimulation; this continues to yield much neurophysiological information. The development of potentially restorative treatment modalities, such as gene therapy, neural transplantation and nanotechnology, hold much promise for surgery, both therapeutically and in revealing further insights into Parkinson's disease pathophysiology.