Nanoplastics and Antibiotic Resistance: A Threat to Health

A recent study conducted by an international research team, including significant contributions from MedUni Vienna, has revealed alarming effects of nanoplastic particles on the efficacy of antibiotics. Published in *Scientific Reports*, the research indicates that these tiny plastic particles not only hinder the effectiveness of antibiotic treatments but may also encourage the emergence of antibiotic-resistant bacteria.

Led by Lukas Kenner from MedUni Vienna, along with Barbara Kirchner from the University of Bonn and Oldamur Hollóczki from the University of Debrecen, the team focused on the interactions between a common antibiotic, tetracycline, and various types of nanoplastics. Tetracycline is a broad-spectrum antibiotic frequently used to treat bacterial infections, including respiratory, skin, and intestinal infections. The plastics studied include polyethylene (PE), polypropylene (PP), polystyrene (PS)—all common in packaging—and nylon 6,6 (N66), prevalent in textiles like clothing and carpets.

Nanoplastics, defined as particles smaller than 0.001 millimeters, pose a significant risk to both human health and the environment due to their diminutive size. Utilizing complex computer models, the researchers demonstrated that these nanoplastic particles can bind to tetracycline, thereby impairing its effectiveness. Kenner noted, "The binding was particularly strong with nylon," highlighting a significant yet underestimated indoor risk: "Micro- and nanoplastic loads are around five times higher indoors than outdoors, primarily due to nylon being released from textiles and entering the body through respiration."

A critical concern raised by the study is the potential for antibiotic resistance. The research found that the binding of tetracycline to nanoplastics could diminish the antibiotic's biological activity while also leading to the drug being transported to unintended areas within the body. This misdirection could diminish its targeted effects and introduce undesirable outcomes. Kenner pointed out a particularly troubling detail: "The local concentration of antibiotics on the surface of the nanoplastic particles can increase, which raises the risk of developing antibiotic-resistant bacteria."

The findings suggest that plastics like nylon 6,6 and polystyrene, which exhibit stronger binding to tetracycline, could elevate the risk of antibiotic resistance. Kenner emphasized the growing global threat of antibiotic resistance, stating, "At a time when antibiotic resistance is becoming an ever-greater threat worldwide, such interactions must be taken into account." The study underscores that exposure to nanoplastics presents a dual risk: a direct threat to health and an indirect influence on the effectiveness of disease treatments.

Kenner concluded with a note of caution regarding future research: "If nanoplastics reduce the effectiveness of antibiotics, determining appropriate dosages poses a significant challenge," urging further investigation into the impact of nanoplastics on other medications.