Exciting developments in bioimaging have proven to be a significant factor for cancer diagnostics and therapeutics.
A review published in the International Journal of Molecular Sciences illustrates the critical role Raman spectroscopy techniques have played in advancing cancer nanomedicine through beneficial characteristics such as high spatial resolution and chemical specificity.
Study: Current and Future Advancements of Raman Spectroscopy Techniques in Cancer Nanomedicine. Image Credit Gorodenkoff/Shutterstock.com
The Need for Advanced Imaging in Cancer Nanomedicine
The field of nanomedicine emerged at the end of the 20th century and has become an exciting and pivotal area of medicine for cancer therapeutics, with Raman spectroscopy being the most commonly used imaging technique for this field.
The role of nanomedicine was crucial for the enhanced permeability and retention (EPR) effect through overcoming obstacles that challenged the delivery of nano-drugs to cancerous areas.
This EPR effect is enabled by nanoparticles that exploit the permeability of cancer vasculature to accumulate into solid tumors. Due to the reduced lymphatic drainage, they can remain in these targeted sites.
This is beneficial for cancer therapeutics as it allows an increase in the number of nano drugs delivered to these specific cancer sites, further enhancing targeted cancer therapy.
The use of nanocarriers to load anticancer drugs enables the accurate release of the drug to the cancerous areas, significant for drug delivery systems, solving the challenge for anticancer drug delivery systems, and reducing drug toxicity in healthy tissues.
Additionally, these nanocarrier systems enable biological barriers to be overcome, such as immune and renal systems and even the blood-brain barrier.
This is beneficial for the treatment of brain tumors, such as glioblastomas, which are notorious for being difficult to treat; however, with the use of cancer nanomedicine, the blood-brain barrier would not be a challenge for these nanoscale drug delivery systems.
The critical role that nanomedicine plays in diagnosing and treating cancer is possible only through dependable imaging techniques such as Raman spectroscopy.
Raman Spectroscopy Background and Benefits
Cancer nanomedicine relies heavily on spectroscopy techniques for various purposes including, (i) characterizing anticancer drug nanocarriers, (ii) imaging cancer tissues, and (iii) detecting cancer biomarkers and monitoring the effects of anticancer drugs on tumors.
Raman scattering is the most commonly used imaging technique due to its high flexibility and the high signal-to-noise ratio. It works using a laser source that irradiates a sample primarily within the UV-Visible-Near IR range (~200 nm to ~800 nm wavelength). This imaging technique would then detect the radiation inelastically scattered from a sample.
The desirability of this method lies within the technique being label-free and non-destructive and the ability to detect changes in the biochemical signatures of cancer cells.
It has high accuracy in discriminating between healthy and diseased cells and can also identify the unique biochemical fingerprints of individual cells and tissues.
Since the spectroscopic fingerprint region of cells and tissues ranges from about 400 cm−1 to about 2500 cm−1, Raman scattering techniques are suitable for investigating samples in physiological conditions and aqueous environments, allowing for both in vitro and in vivo applications.
Raman Spectroscopy Within Cancer Nanomedicine
While there are many examples of Raman scattering methods, the main techniques used for cancer diagnosis and therapy include Spontaneous Raman Scattering, Surface-Enhanced Raman Scattering (SERS), Surface-Enhanced Resonance Raman Scattering (SERRS), and Spatially Offset Raman Spectroscopy (SORS).
Additionally, Coherent Anti-Stokes Raman Spectroscopy (CARS) is predominantly used for in vitro and in vivo investigations on the pharmacokinetics of anticancer drugs and nanocarriers, due to its high sensitivity and high-speed imaging.
Within cancer nanomedicine, nano theranostics aims to integrate diagnostic imaging with therapeutic interventions, overcoming challenges faced by effective cancer therapies. This resulted in combining drug delivery systems with various imaging techniques such as MRI, CT, or PET scans.
The use of nanoparticles for this collaboration as imaging contrast agents enhanced the benefits of this cancer nano theranostic system.
The use of gold nanoparticles in both Raman imaging and photothermal therapy can be found in literature such as the synthesis of gold nanostars and assessing their suitability for diagnostic and therapeutic efficacy in a mouse model of breast cancer cells.
Raman scattering techniques have also been coupled with other diagnostic and therapeutic methods to create nanoparticle-free theranostic platforms.
Raman spectroscopy is a versatile and accurate bioimaging method for cancer nanomedicine, and advancements could innovate this field entirely.
While this industry is already established, continual research development aims to enhance deeper penetration into tissues, and improve acquisition speeds, the specificity, and sensitivity for in vitro and in vivo experiments.
This imaging technique is instrumental for the advancement of cancer nanomedicine, and innovations in this field will further the quality of care given to patients.
Continue reading: Using Optical Microscopy for Nanotube Research.
Canetta, E., (2021) Current and Future Advancements of Raman Spectroscopy Techniques in Cancer Nanomedicine. International Journal of Molecular Sciences, 22(23), p.13141. Available at: https://www.mdpi.com/1422-0067/22/23/13141