Study Confirms: ‘Extreme Lack of Consistency’ Hampers the Potential of Nanosized Medicines

Nanomedicine, the application of extremely tiny – nanoscale – materials in disease prevemntion, diagnostics and therapeutics, holds the promise of revolutionizing medicine across nearly all disciplines and specialties. From a biomedical point of view, the ultra-small size of nanomedicines, allows them to reach otherwise inaccessible sites within the human body, including the cell nucleus. However, today, the promise of these extremely small materials – just a few hundred nanometers in size, which is significantly smaller than the width of a human hair, has yet to be fully realized. [1][2]

Morteza Mahmoudi, Ph,D., an assistant professor in Michigan State University’s (MSU) Department of Radiology, studies factors impeding the development of this very promising technology, and found that one of the factors hampering the development of nanomedicine is a lack of standards when it comes to how these medicines are analyzed and characterized in the laboratory.

Mahmoudi was part of a team that recently revealed a shocking level of disagreement between lab results that researchers rely on as they create and test new nanomedicines. [3] That team included Ali Ashkarran Ph.D. at MSU and collaborators at the University of California, Berkeley and the Karolinska Institute in Sweden.

Mahmoudi, explains why addressing such disagreements with stronger standards will help ensure future nanomedicines are safe, effective and successful.

A spotlight of Nanomedicines
Although nanotechnologies contribute to almost every field of science, including physics, materials science, chemistry, biology, computer science, and engineering, applications in human health, especially the treatment of cancer (where they are being used to help improve immunotherapy) and cardiovascular disease, are especially norteworthy [4][5][6]

In addition, nanomedicines took the spotlight during the COVID-19 pandemic with researchers using these very small and intricate materials to develop diagnostic tests and vaccines. [7]

An unmet need for standards
And while nanomedicine are already succesfully used in many healthcare applications, there remains an unmet need to develop and implement new standards to study them.

“Although there are success stories in the field, many scientists — including myself — believe there aren’t enough, especially considering the amount of effort and taxpayer money we’ve invested in nanomedicine development,” Mahmoudi noted.

To that end, researchers have been working to improve the safety and efficacy of nanomedicine through various approaches. These include modifying study protocols, methodologies and analytical techniques to standardize the field and improve the reliability of nanomedicine data.

“Aligned with these efforts, my team and I have identified several critical but often overlooked factors that can influence the performance of a nanomedicine, such as a person’s sex, prior medical conditions and disease type.[8][9] Taking these factors into account when designing studies and interpreting results could enable researchers to produce more reliable and accurate data and lead to better nanomedicine treatments,” Mahmoud added.

An example
“Just like all medications, once they enter the bloodstream, nanomedicines are surrounded by proteins from the body. This ‘protein coating,’ known as the ‘protein corona,’ which is the layer of proteins that spontaneously forms on the surface of nanoparticles immersed in biological fluids, gives nanoparticles a biological identity. This biological identity determines how the body will recognize and interact with these tiny particles.  This is similar to how the immune system has specific reactions against certain pathogens and allergens,” Mahmoud explained.

“What is important to understand is that the protein “corona changes” many of the physicochemical properties of nanoparticles. This may include the size, surface charge, and aggregation state. In turn, these changes affect the biological fate of nanoparticles, which includes their pharmacokinetics, biodistribution, and therapeutic efficacy. Hence, knowing the precise type, amount and configuration of these proteins and other biomolecules attached to the surface of nanomedicines is critical to determine a safe and effective dosages for specific treatments. Therefor, robust characterization of the “protein corona” is really vital for prediction of the safety, biodistribution, and both the diagnostic and therapeutic efficacy of nanomedicines,” he continued.

“However, one of the few available approaches to analyze the composition of protein coronas requires instruments that many nanomedicine laboratories lack. [10] So these labs typically send their samples to separate proteomics facilities to do the analysis for them. Unfortunately, many facilities use different sample preparation methods and instruments, which can lead to differences in results,” Mahmound said.

Today, liquid chromatography coupled to mass spectroscopy (LC-MS/MS) remains the dominant methodology to characterize the identity of the protein corona. However, what remained unknown to researchers is the role of mass spectroscopy in causing technical variations in assessing the composition of the protein corona, and to what extent such proteomics outcomes can affect the interpretation of the nanobio interfaces. [3]

Shocking results
“Because we wanted to test how consistently these proteomics facilities analyzed protein corona samples, we sent biologically identical protein coronas to 17 different labs in the U.S. for analysis. The results were not what we had hoped for. Out of 4,022 identified unique proteins, only 73, less than 2%, of the proteins the labs identified were the same.” Mahmound added. [3]

“Our results clearly reveal that there is an ‘extreme lack of consistency’ in the analyses researchers use to understand how nanomedicines work in the body. This may pose a significant challenge not only to ensuring the accuracy of diagnostics, but also the effectiveness and safety of treatments based on nanomedicines,” he concluded.

Reference
[1] Tinkle S, McNeil SE, Mühlebach S, Bawa R, Borchard G, Barenholz YC, Tamarkin L, Desai N. Nanomedicines: addressing the scientific and regulatory gap. Ann N Y Acad Sci. 2014 Apr;1313:35-56. doi: 10.1111/nyas.12403. Epub 2014 Mar 27. PMID: 24673240.
[2] Flühmann B, Ntai I, Borchard G, Simoens S, Mühlebach S. Nanomedicines: The magic bullets reaching their target? Eur J Pharm Sci. 2019 Feb 1;128:73-80. doi: 10.1016/j.ejps.2018.11.019. Epub 2018 Nov 20. PMID: 30465818.
[3] Ashkarran AA, Gharibi H, Voke E, Landry MP, Saei AA, Mahmoudi M. Measurements of heterogeneity in proteomics analysis of the nanoparticle protein corona across core facilities. Nat Commun. 2022 Nov 3;13(1):6610. doi: 10.1038/s41467-022-34438-8. PMID: 36329043; PMCID: PMC9633814.
[4] Bayda S, Adeel M, Tuccinardi T, Cordani M, Rizzolio F. The History of Nanoscience and Nanotechnology: From Chemical-Physical Applications to Nanomedicine. Molecules. 2019 Dec 27;25(1):112. doi: 10.3390/molecules25010112. PMID: 31892180; PMCID: PMC6982820.
[5] Martin JD, Cabral H, Stylianopoulos T, Jain RK. Improving cancer immunotherapy using nanomedicines: progress, opportunities and challenges. Nat Rev Clin Oncol. 2020 Apr;17(4):251-266. doi: 10.1038/s41571-019-0308-z. Epub 2020 Feb 7. PMID: 32034288; PMCID: PMC8272676.
[6] Mahmoudi M, Yu M, Serpooshan V, Wu JC, Langer R, Lee RT, Karp JM, Farokhzad OC. Multiscale technologies for treatment of ischemic cardiomyopathy. Nat Nanotechnol. 2017 Sep 6;12(9):845-855. doi: 10.1038/nnano.2017.167. PMID: 28875984; PMCID: PMC5717755.
[7] Nanotechnology versus coronavirus. Nat Nanotechnol. 2020 Aug;15(8):617. doi: 10.1038/s41565-020-0757-7. PMID: 32764720.
[8] Hajipour MJ, Aghaverdi H, Serpooshan V, Vali H, Sheibani S, Mahmoudi M. Sex as an important factor in nanomedicine. Nat Commun. 2021 May 20;12(1):2984. doi: 10.1038/s41467-021-23230-9. PMID: 34017011; PMCID: PMC8170671.
[9] Hajipour MJ , Laurent S , Aghaie A , Rezaee F , Mahmoudi M . Personalized protein coronas: a “key” factor at the nanobiointerface. Biomater Sci. 2014 Sep 29;2(9):1210-1221. doi: 10.1039/c4bm00131a. Epub 2014 May 30. PMID: 32481892.
[10] Mahmoudi M. The need for improved methodology in protein corona analysis. Nat Commun. 2022 Jan 10;13(1):49. doi: 10.1038/s41467-021-27643-4. PMID: 35013179; PMCID: PMC8748711.

The quotes in this article are excerpts and adaptations from an article originally published in The Conversation.

Featured image: A colorized microscope image shows nanosized disks being developed as a cancer therapy. The two disks, in an off-white color, are attached to a larger round and bumpy object (reminiscent of a chocolate truffle) shown in blue. This object is a cell derived from bone marrow. Photo courtesy: Brenda Melendez and Rita Serda/National Cancer Institute, National Institutes of Health, CC BY-NC