April 2022

The treatment of cancer has evolved drastically from years prior and nanomatierials are paving the way for new types of treatment. Nanomaterials are organic and inorganic compounds that are smaller than several hundred nanometers that can be used for passive tumor targeting.1 Agents such as polymeric micelles, liposomes, dendrimers and polymeric particles have become a more effective way to treat cancer because it can target the specific site of the tumor microenvironment and have less severe side effects systemically.1 The ability to target the tumor alone without major complications to body of the patient would help to improve quality of life during treatment and could help promote better outcomes in the future due to less severe side effects.

A current nanoparticle therapy that is being tested is the use of PDT and PTT where a photosensitizer accumulates in the tumor microenvironment and when irradiated with a certain wavelength of light will cause a hyperthermic environment leading to tumor necrosis.2 The targeted delivery of this system would provide a more precise treatment and has hopes of minimizing the adverse reactions that are typically associated with chemotherapy.

Another option that is currently on the market would be the use of Enhanced Permeability and Retention. Tumor growths have a rapid expansion of blood vessel networks to account for the increased need of oxygen and blood. These vessels tend to form abnormally with larger and leakier pores where the EPR can target by using a passive accumulation of the chemotherapy agent into the tumor site.3 An example of this therapy would be PEG-coated doxorubicin which has the water soluble coating to better penetrate breast cancer tissue. With the faster uptake of these charged micelle coated particles, studies showed that nanoparticles can diffuse throughout the entire tumor within 48 hours depending on the malignancy.3 Although this is a promising therapy, it is not as effective against treating solid tumors due to large hypoxic zones in those environments. In order to combat those issues, this therapy can be administered with angiotensin II to increase blood pressure, topical nitrous oxide agents to encourage blood flow and with photosensitizer particles to promote hyperthermic necrosis which can help improve outcomes.3

Although many of these treatments are still under research, delivery systems such as micelles and liposomes have unique characteristics that can make a large impact on the efficacy of cancer therapies. Their high surface-volume ratios, the ability to carry a large number of anti-cancer drugs and the enhanced permeability and retention have proven to be key in the effectiveness of nanomaterials.1 Many of these therapies are still in the development phase but further intensive research could make a promising future for nanomaterials.

References:

[1] Bae, Ki Hyun et al. “Nanomaterials for cancer therapy and imaging.” Molecules and cells vol. 31,4 (2011): 295-302. doi:10.1007/s10059-011-0051-5

[2] Cheng, Z., Li, M., Dey, R. et al. Nanomaterials for cancer therapy: current progress and perspectives. J Hematol Oncol 14, 85 (2021). https://doi.org/10.1186/s13045-021-01096-0

[3] National Cancer Institute. (2017, August 8.) Benefits of Nanotechnology for Cancer. National Institute of Health. https://www.cancer.gov/nano/cancer-nanotechnology/benefits