Compost is known for helping the environment by putting waste to good use, but in an unexpected way, it may also give rise to more effective chemotherapy treatments. According to new research, it turns out that bacteria found in compost harbor a type of protein that can be used for improved drug delivery.

A recent study published in the journal Angewandte Chemie International Edition details a promising method in which protein cages can be modified to transport drugs. Having shown success during in vitro tests, this process could soon allow for enhanced drug delivery within the body and reduce the side effects of chemotherapy drugs. 

The Role of Proteins

Proteins are among the most important components in our bodies, performing a repertoire of tasks that keep us alive and healthy; mainly working in cells, they drive metabolism, support the immune system, and strengthen muscles. Variation in amino acids — the building blocks of proteins — determines how a protein will act and what its primary job will be. 

“Nearly everything that happens in a cell, from building its protective membranes to producing energy, requires a protein,” said study author Taylor Szyszka, a postdoctoral researcher in synthetic biology at the University of Sydney, in a statement.

Some proteins take the form of hollow, spherical structures called protein cages, acting as protective containers that deliver materials to cells. The new study focuses on encapsulins, a subgroup of protein cages that grant cargo extra protection from threats and prevent it from escaping. 

Read More: Early Prostate Cancer Diagnosis Soon Possible with Simple Urine Sample

Packaging a Protein Cage

Researchers involved with the study found a way to unlock the potential of an encapsulin that was originally discovered in bacteria from a compost heap in 2019. By fusing this encapsulin to another protein, they were able to add drug molecules before the structure could assemble. If the encapsulin had assembled before adding cargo, it would have been unable to hold or transport drugs. 

The researchers packed the encapsulin with doxorubicin (a chemotherapy drug used to treat various cancers), which triggered the structure’s assembly in vitro (outside a living organism).

Since doxorubicin is a fluorescent drug, the fluorescent signal that the researchers saw once they loaded the encapsulin told them the test was a success.

“This is a first,” said Szyszka in the press release. “Until now, it hasn’t been possible for encapsulins to efficiently load drugs. Previously, this could happen only by pulling encapsulins apart, loading them with a drug, and then reassembling them, a messy process which compromises the encapsulin’s stability.”

Improving Chemotherapy Drug Delivery

The results of the study offer hope for a more precise way of delivering cytotoxic drugs, commonly used in chemotherapy to kill cancer cells. Treatment with these drugs often causes side effects like nausea, hair loss, and fatigue. Improving the delivery of drugs to the correct site in the body could help lessen these side effects.

While protein cages are mostly touted as an option for cancer treatment, scientists have targeted other uses for them as well: They could potentially be used to modulate immune responses, treat skin conditions like pigmentation disorders, and deliver therapeutics through the eye. 

Next, researchers hope to refine the encapsulin used in the study so it can aim for specific destinations in the body. For example, if the encapsulin holds a drug meant to treat liver disease, it should be able to head for liver cells. 

“We’ve built the car, now we need to learn how to drive it,” concluded Szyszka in the press release.

This article is not offering medical advice and should be used for informational purposes only.

Read More: The Gut Microbiome Could Help Our Bodies Fight Cancer

Article Sources

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

Jack Knudson is an assistant editor at Discover with a strong interest in environmental science and history. Before joining Discover in 2023, he studied journalism at the Scripps College of Communication at Ohio University and previously interned at Recycling Today magazine.