Molecular interactions and dynamics of microplastics in indoor dust with lung-inflammatory receptors: A study in academic settings

Airborne microplastics (MPs) are prevalent indoors, and due to their low aerodynamic diameter, they can be inhaled, posing potential health risks. Although the toxic effects of airborne MPs have been explored using in vivo and in vitro models, the interactions between MPs and cellular receptors remain understudied. In this research, dust samples from a confined space within an academic setting were investigated for microplastics (MPs) and their abundance. Further, the most prevalent microplastics were used to study receptor binding and competition interaction studies using the In-Silico method against natural agonists and antagonists of major inflammatory receptors, including the human platelet-activating factor receptor (PAFR), C-X-C motif chemokine receptor 1 (CXCR1), β2-adrenergic receptor (β2-AR), and toll-like receptor 2 (TLR-2). Results revealed that polyester (PE) was the predominant polymer, accounting for 23.96 % of the samples. Analysis indicated that a monomer of PET, Ethylene Terephthalate (ET), exhibited a high binding affinity of -6.5 kcal/mol with the PAFR receptor. Additionally, the molecular dynamics and protein-ligand interaction study, which involves hydrogen bonding, explains the differential binding effect of ET and the control compound with the targeted receptor. The complex was formed between the ET and the receptors of β2-AR, CXCR1, and TLR-2, with a maximum of seven and a minimum of one hydrogen bond throughout the simulation. This research lays a foundation for understanding the potential health implications of MPs in confined office spaces, underscoring the need for further in vivo and in vitro examinations.