The advancement in nanotechnology has mainly been associated with the versatility of nanoparticles and their ability to be functionalized with various properties to meet innovative applications. The thermo-optical properties of nanoparticles further their use within applications, however, with these advanced particles being within a nanoscale, characterization of various properties may be challenging. This article will highlight how lasers can be used to study nanoparticle characteristics, such as thermo-optical properties, and their benefit for advancing nanotechnology applications.
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Benefits of Nanoparticles
Photothermal properties of nanoparticles are significant for various applications, such as cancer therapy, where nanoparticles can be used as contrast agents or tumor imaging.
Using nanoparticles for this application can be more beneficial than other optical approaches due to their small size and high surface area to volume ratio, which allows them to access deeper and more obscure areas of the body. This translates into providing a higher resolution and sensitivity toward tumors than conventional optical methods.
The surfaces of nanoparticles can be functionalized to further targeting ability and enhance their specificity and sensitivity to areas of concern. Cancer cells can be characterized to a higher degree once accumulated in this area due to the enhanced permeability and retention effect that allows nano-sized particles to accumulate in tumor tissue more readily than in healthy tissue.
Previous researchers have illustrated the benefit of nanoparticles for use in clinical photothermal and photoacoustic techniques. The innovative nano-scale particles have high absorption for radiation, including visible and near-infrared radiation with the addition of deep tissue penetration. They are also low in toxicity, photostable and can be used for precise molecular targeting with surface functionalization with antibodies or proteins.
The advanced characterization of nanoparticle properties has led to two gold nanoparticles that have been approved for clinical trials in cancer research.
The advancement in nanotechnology and its translation into clinical use enhances patient treatment and biomedical research.
The significance of lasers for the study of nanoparticles is multi-fold, with a novel approach to eliminating cancer cells to understanding how nanoparticles can absorb various light and radiation wavelengths.
Lasers Within Nanotechnology
The ability of nanoparticles to absorb radiation to a high level can be exploited for the treatment of cancer.
Lasers are used to excite these particles, which absorb the energy and convert it into thermal energy; this can heat the nanoparticles and tissue and ultimately be used to damage and kill cancer cells.
This method of targeting malignancies within patients through a precise and safe approach can further the field of personalized or precision medicine, addressing the cancerous areas but preserving the healthy tissue.
Successes in this area have consisted of continual research based on using advanced methods of characterizing the properties of nanoparticles and this includes the use of lasers.
Using lasers to characterize the thermo-optical characteristics of nanoparticles not only enhances their use in cancer therapy but also a range of other applications, including but not limited to, photonic devices, photo-thermal therapy, biosensing, electronics and even data storage.
To optimize the efficacy of nanoparticles for cancer therapy, the interaction between light and nanoparticles would require investigation, as well as the measurement of the temperature of heated nanoparticles.
The Niels Bohr Institute and the Faculty of Health Sciences within the University of Copenhagen, Denmark, have previously undertaken research that utilizes lasers and nanoparticles for cancer therapy.
The research lead of this study is a biophysicist named Dr Lene Oddershede who has commented on the research:
The effectiveness depends on the right combination between the structure and material of the particles, their physical size, and the wavelength of the light.
With a variety of lasers and light wavelengths available, experimenting with these and the impact they have on nanoparticles, can be a fruitful method of finding the optimum laser as well as the optimum nanoparticle for a certain application.
Dr Oddershede’s research group found success when using nanoparticles 150 nm in size as well as with a core constructed of glass and coated with gold.
The laser that was used consisted of near-infrared light as this was found to be the most effective at penetrating tissue as well as being safe to use as opposed to traditional radiation therapy lasers that can result in damage.
The researchers confirmed their hypothesis with a positron emission tomography (PET) scan that was used an hour after the treatment of mice models, which demonstrated the elimination of cancer cells, an effect that continued for approximately two days after the treatment.
The future of this research consists of using PET scans to locate cancerous cells to irradiate them with lasers for cancer metastasis as well as possibly coating nanoparticles with a chemotherapy drug, which can be activated and released by heat stimuli provided by laser irradiation.
Significance and Future Outlook
Research into lasers has continually benefited the advancement of nanoparticle application with further knowledge of thermo-optical properties; this can be seen with recent research into using femtosecond laser pulses to study silver nanoparticle colloids.
Understanding the various levels of excitation laser powers and the result of optical properties is critical for the development of a wide range of applications, from medicine to biosensing and even electronics.
While this research is significant for informing the optimum size and surface functionalization materials of nanoparticles for a particular application, uses within a clinical setting are still progressing due to challenges concerning real-world patients.
The toxicity of the lasers and nanoparticles requires extra vigilant investigation, and this may be a challenge with the use of metallic nanoparticles that may have some adverse effects.
The development of these nanoparticles with thermo-optical properties holds great potential through laser technology, with the promise of precise targeting and treatment of malignancies.
This can only propel cancer research into a brighter future, with better care provided to the most vulnerable patients, reducing the need for drawn-out, length treatment plans with a high expense.
References and Further Reading
GEN Magazine. 2016. Lasers and Nanoparticles: The Future of Cancer Treatment Is Here. [online] Available at: https://www.genengnews.com/topics/translational-medicine/lasers-and-nanoparticles-the-future-of-cancer-treatment-is-here/ [Accessed 18 April 2022].
Karimzadeh, R. and Mansour, N., 2010. The effect of concentration on the thermo-optical properties of colloidal silver nanoparticles. Optics & Laser Technology, 42(5), pp.783-789. Available at: https://doi.org/10.1016/j.optlastec.2009.12.003
Mamdouh, S., Mahmoud, A., Samir, A., Mobarak, M. and Mohamed, T., 2022. Using femtosecond laser pulses to investigate the nonlinear optical properties of silver nanoparticles colloids in distilled water synthesized by laser ablation. Physica B: Condensed Matter, 631, p.413727. Available at: https://doi.org/10.1016/j.physb.2022.413727
Pustovalov, V., Astafyeva, L., Galanzha, E. and Zharov, V., 2010. Thermo-optical analysis and selection of the properties of absorbing nanoparticles for laser applications in cancer nanotechnology. Cancer Nanotechnology, 1(1-6), pp.35-46. Available at: 10.1007/s12645-010-0005-1