Cancer affects millions of people around the world every year; More than 39% of men and women will develop cancer at some point in their lives. Chemotherapy is the most commonly used standard cancer treatment, and targeted delivery of these drugs to the tumor site increases their effectiveness. However, excess medication can still circulate in the rest of the body and cause several side effects, including anemia, chronic infections, hair loss, jaundice, and fever.
A number of proposed methods have been attempted to remove undesirable chemotherapeutic agents, particularly the widely used drug doxorubicin (DOX), from the blood. But these methods have resulted in insufficiently low DOX removal. Additional strategies that use electrically charged nanoparticles to bind DOX become less effective when exposed to the charged molecules and proteins found in blood, despite the addition of materials designed to protect the binding capacity.
A collaborative team that included scientists from Pennsylvania State University and the Terasaki Institute for Biomedical Innovation (TIBI) has developed a method to address these challenges.
The method described in Materials Today Chemistry is based on hairy cellulose nanocrystals -; Nanoparticles evolved from the main component of plant cell walls and engineered to have an immense number of polymer chain “hairs” extending from each end. These hairs increase the potential ability of the nanocrystals to capture active substances well beyond that of conventional nanoparticles and other materials.
To create the hairy cellulosic nanocrystals that chemotherapy drugs can capture, the researchers chemically treated cellulosic fibers made from softwood pulp and gave the hair a negative charge, making it stable against charged molecules in the blood. This overcomes the problems of conventional nanoparticles, the charge of which can become inert or reduced upon contact with blood, thereby limiting the number of positively charged drug molecules to which they can bind to an insignificant number.
The binding effect of the nanocrystals was tested in human serum, the protein-rich liquid part of blood. For every gram of hairy cellulose nanocrystals, more than 6,000 milligrams of DOX were effectively removed from the serum. This means an increase in DOX separation by two to three orders of magnitude compared to other currently available methods.
In addition, the capture of DOX occurred immediately after the addition of the nanocrystals, and the nanocrystals had no toxic or harmful effects on red blood cells in whole blood or on cell growth of human umbilical cord cells.
Such an effective means of incorporating drugs into the body can have a great impact on cancer treatment as the doses can be increased to more effective levels without fear of adverse side effects.
An example of such an application was provided by lead researcher Amir Sheikhi, assistant professor of chemical and biomedical engineering at Penn State University. “For some organs, such as the liver, chemotherapy can be administered locally through catheters. If we could place a device based on nanocrystals to trap the excess medication leaking from the liver’s inferior vena cava, a large blood vessel, clinicians could potentially give higher doses. ”Chemotherapy to kill cancer faster without getting away Worrying about damaging healthy cells. Once treatment is complete, the device could be removed. “
In addition to removing excess chemotherapy drugs from the body, the hairy cellulosic nanocrystals could also remove other undesirable substances such as toxins and addictive substances from the body, and experiments have shown the effectiveness of the nanocrystals in other separation applications, such as recovering valuable elements from electronic waste.
What started out as a relatively simple concept has evolved into a highly effective means of separating substances. This creates the potential for far-reaching and effective biomedical and materials science applications. “
Ali Khademhosseini, Director and CEO, Terasaki Institute for Biomedical Innovation
Terasaki Institute for Biomedical Innovation
Young, SAE, et al. (2021) Development of hairy cellulose nanocrystals for drug capture in chemotherapy. Materials today chemistry. doi.org/10.1016/j.mtchem.2021.100711.