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Posted: Jun 13, 2017
Nanotechnology in healthcare (Part 1: Fitness monitoring, diagnostics and prevention)
(Nanowerk Spotlight) Healthcare is concerned with the maintenance or restoration of the health of the body or mind via the diagnosis, treatment, and prevention of disease, illness, injury, and other physical and mental impairments.
Nanotechnology is becoming a crucial driving force behind innovation in medicine and healthcare, with a range of advances including nanoscale therapeutics, biosensors, implantable devices, drug delivery systems, and imaging technologies.
A nanotechnology-based system, for instance to eradicate cancer, needs four elements:
1) Molecular imaging at the cellular level so that even the slightest overexpressions can be monitored;
2) effective molecular targeting after identifying specific surface or nucleic acid markers;
3) a technique to kill the cells, that are identified as cancerous based on molecular imaging, simultaneously by photodynamic therapy or drug delivery, and
4) a post molecular imaging technique to monitor the therapeutic efficacy.
In the following, we'll cover these four areas and provide a comprehensive overview of healthcare advances that may be possible through nanotechnology, ranging from fitness monitoring, prevention, diagnosis to therapy, and everything in between.
When you hear 'fitness monitoring' you probably think of the plethora of smartphone apps and the bracelets and wristbands that are on the market. Nanomaterials are going to open new realms of possibility for these monitoring gadgets.
In a hospital, a patient wears a printed graphene RFID tag on his or her arm. The tag, integrated with other 2D materials, can sense the patientís body temperature and heartbeat and sends them back to the reader. The medical staff can monitor the patientís conditions wirelessly, greatly simplifying the patientís care.
In a care home, battery-free printed graphene sensors can be printed on elderly peoples' clothes. These sensors could detect and collect elderly peopleís health conditions and send them back to the monitoring access points when they are interrogated, enabling remote healthcare and improving quality of life.
More examples of these futuristic biofunction monitors include temporary tattoos or electronic stickers:
Accurate and early diagnosis of disease remains one of the greatest challenges of modern medicine. As with any advance in diagnostics, the ultimate goal is to enable physicians to identify a disease as early as possible. Nanotechnology is expected to make diagnosis possible at the cellular and even the sub-cellular level with enhanced imaging techniques and high-performance sensors.
More lives could be saved by early detection of cancer than by any form of treatment at advanced stages. Circulating tumor cells (CTCs), which are viable cells derived from tumors, are hypothesized to represent the origin of metastatic disease.
Nanotechnology can be used to develop devices that indicate when those markers appear in the body and that deliver agents to reverse premalignant changes or to kill those cells that have the potential to become malignant.
With increasing accuracy, liquid biopsies – where CTCs are isolated from blood samples – are becoming a viable complement or even alternative to invasive biopsies of metastatic tumors.
CTCs are of great interest for evaluating cancer dissemination, predicting patient prognosis, and also for the evaluation of therapeutic treatments, representing a reliable potential alternative to invasive biopsies and subsequent proteomic and functional genetic analysis.
Quantum dots in particular have finally taken the step from pure demonstration experiments to real applications in imaging. In recent years, scientists have discovered that these nanocrystals can enable researchers to study cell processes at the level of a single molecule. This may significantly improve the diagnosis and treatment of cancers. Fluorescent semiconductor quantum dots are proving to be extremely beneficial for medical applications, such as high-resolution cellular imaging.
Another major challenge of modern medicine is the detection of pathogens at the point-of-care (POC), particularly in underprivileged areas. Especially the early detection of foodborne pathogenic bacteria is critical for preventing disease outbreaks and preserving public health. Unfortunately, current detection techniques such as ISO method 6579, fluorescent-antibody (FA), enzyme-linked immunosorbent assay (ELISA), or polymerase chain reaction (PCR) are time-consuming, cumbersome, and have limited sensitivity. They are inadequate as they lack the ability to detect bacteria in real time.
Possible nanotechnology solutions include a graphene-based wireless sensor that could make 24-hour healthcare easier to achieve by enabling wireless monitoring of various biomedical events in order to gain a more comprehensive assessment of the wearer's healthcare status. Other solutions include nanoparticles that can then selectively attach themselves to any number of food pathogens. Handheld sensors employing either infrared light or magnetic materials, could then note the presence of even minuscule traces of harmful pathogens.
The advantage of such a system is that literally hundreds and potentially thousands of nanoparticles can be placed on a single nanosensor to rapidly, accurately and affordably detect the presence of any number of different bacteria and pathogens. A second advantage of nanosensors is that, given their small size, they can gain access into the tiny crevices where the pathogens often hide.
Smart contact lens. Schematics of fully passive, transparent, and conformal all-graphene harmonic sensor designed for various point-of-care monitoring and wireless biomedical sensing. The right panel illustrates an eye-wearable device (smart contact lens) based on the all-graphene harmonic sensor, which may detect in real time the pathogen, bacteria, glucose, and infectious keratitis. (Image: Pai-Yen Chen's research group, Wayne State University) (click on image to enlarge)
In a clinical environment, recent achievements with nanosensor platforms demonstrate the enormous potential of fluorescent nanosensors for clinical applications requiring continuous in vivo monitoring of important biomarkers. Such in vivo diagnostics and sensing can be accomplished, for instance, by utilizing a biocompatible hydrogel to encapsulate the fluorescent nanosensors and then implanting the encapsulated material
subcutaneously to detect analyte concentrations in its vicinity (see: "Quantitative Tissue Spectroscopy of near Infrared Fluorescent Nanosensor Implants").
The optical nature of this kind of detection scheme can provide real-time readout with high spatial and temporal resolution. These platforms hold great promise as alternatives to conventional natural recognitions elements, both for diagnostics and for treatment purposes, to improve patient care.