Nanotechnology for neuroscience

(Nanowerk Spotlight) Notwithstanding the progress neuroscientists have made in understanding the microscale function of single neurons and the macroscale activity of the human brain – a comprehensive understanding of the brain still remains an elusive goal.

The BRAIN Initiative, launched in 2013, seeks to deepen understanding of the inner workings of the human mind and to improve how we treat, prevent, and cure disorders of the brain. Key goals of the BRAIN Initiative are:

Develop new technologies to explore how the brains cells and circuits interact at the speed of thought, ultimately uncovering the complex links between brain function and behavior. Accelerate the development and application of new neurotechnologies. Enable researchers to produce a dynamic picture of the brain functioning in real time. Explore how the brain records, processes, uses, stores, and retrieves vast quantities of information. Shed light on the complex links between brain function and behavior, incorporating new theories and computational models. Help bring safe and effective products to patients and consumers.

Over the past several years, nanoscale analysis tools and in the design and synthesis of nanomaterials have generated optical, electrical, and chemical methods that can readily be adapted for use in neuroscience and brain activity mapping.

A review paper in Advanced Functional Materials ("Nanotechnology for Neuroscience: Promising Approaches for Diagnostics, Therapeutics and Brain Activity Mapping") summarizes the basic concepts associated with neuroscience and the current journey of nanotechnology towards the study of neuron function by addressing various concerns on the significant role of nanomaterials in neuroscience and by describing the future applications of this emerging technology.

The main focus of this article is to review the implications of these recent findings and raise future research directions to develop nanoscale materials for the advancement of neuroscience applications. Nanoneuroscience is an emerging field that can greatly impact the understanding of neural circuitry and neurological treatment.

Schematic illustration of the relationship between nanotechnology and neuroscience. The two fields are closely intertwined, and it is difficult to clearly separate any one subfield. A new field – nanoneuroscience – is emerging with the combination of two different sciences to gain a better understanding of brain function. (Reprinted with permission by Wiley-VCH Verlag)

Nanoneuroscience is a science that bridges neuroscience and nanotechnology (see figure above) by concurrently addressing the fundamental goals of these two separate fields. Nanotechnology is the science that deals with materials at nanoscale levels, and the collaboration of this field with bioengineering and neuroscience can transform basic science into novel materials and devices for the treatment and monitoring of the pathological condition of neurological disease.

The main goals of this technology are to understand how the nervous system operates and how neurons communicate and organize themselves into ordered networks in various action and mental states to treat the disease related to nervous system.

The collaboration between nanotechnology and neuroscience, though still at the early stages, utilizes broad concepts, such as drug delivery, cell protection, cell regeneration and differentiation, imaging and surgery, to give birth to novel clinical methods in neuroscience.

The potential applications of this union are not limited to those named above, as the assimilation of nanotechnology into optogenetics and the piezoelectric effect further indicates its prospective applications in neuroscience.

Ultimately, the clinical translation of nanoneuroscience implicates that central nervous system (CNS) diseases, including neurodevelopmental, neurodegenerative and psychiatric diseases, have the potential to be cured, while the industrial translation of nanoneuroscience indicates the need for advancement of brain-computer interface technologies.

Recently different types of nanomaterials (organic/inorganic nanoparticle systems) have been used in the field of nanoneuroscience, and their potential applications have been governed.

Schematic representation of different types of nanoparticle-based platforms and their roles in neuroscience applications. These nanoparticles have been extensively used in neuroscience to investigate their potential applications for the diagnosis, treatment and monitoring of several neurological diseases. (© Wiley-VCH Verlag) (click on image to enlarge)

Diagnostic and Therapeutic Applications of Nanotechnology in Neuroscience

In this section, the authors critically appraise nanomaterials for diagnostic and therapeutic purposes – or theranostics when they possess a dual function – including drug delivery, neuroprotection, neural regeneration, neuroimaging and neurosurgery:

Potential applications of nanomaterials for drug delivery to the central nervous system; Nanomaterials for neuroprotection; Nanomaterial-based approaches for neural regeneration; Applications of nanotechnology for neuroimaging Nanotechnology in neurosurgery

Future Developing Arenas in Nanoneuroscience

The Brain Activity Map (BAM) Project aims to map the neural activity of every neuron across all neural circuits with the ultimate aim of curing diseases associated with the nervous system. The announcement of this collaborative, public-private research initiative in 2013 by President Obama has driven the surge in developing methods to elucidate neural circuitry. Three current developing arenas in the context of nanoneuroscience applications that will push such initiative forward are 1) optogenetics, 2) molecular/ion sensing and monitoring and 3) piezoelectric effects.

In their review, the authors discuss these aspects in detail.

Neurotoxicity of Nanomaterials

By engineering particles on the scale of molecular-level entities – proteins, lipid bilayers and nucleic acids – we can stereotactically interface with many of the components of cell systems, and at the cutting edge of this technology, we can begin to devise ways in which we can manipulate these components to our own ends. However, interfering with the internal environment of cells, especially neurons, is by no means simple.

"If we are to continue to make great strides in nanoneuroscience, functional investigations of nanomaterials must be complemented with robust toxicology studies," the authors point out. "A database on the toxicity of materials that fully incorporates these findings for use in future schema must be developed. These databases should include information and data on 1) the chemical nature of the nanomaterials in complex aqueous environments; 2) the biological interactions of nanomaterials with chemical specificity; 3) the effects of various nanomaterial properties on living systems; and 4) a model for the simulation and computation of possible effects of nanomaterials in living systems across varying time and space. If we can establish such methods, it may be possible to design nanopharmaceuticals for improved research as well as quality of life."

The marriage of neuroscience and nanotechnology may provide a solution to many central nervous system disorders, from neurodevelopmental disorders to psychiatric disorders and motor and sensory disorders.

"However, challenges in nanoneuroscience are present in many forms, such as neurotoxicity; the inability to cross the blood-brain barrier; the need for greater specificity, bioavailability and short half-lives; and monitoring of disease treatment," the authors conclude their review. "The nanoneurotoxicity surrounding these nanomaterials is a barrier that must be overcome for the translation of these applications from bench-to-bedside. While the challenges associated with nanoneuroscience seem unending, they represent opportunities for future work."