Microplastics in nucleus pulposus tissue of humans revealed by Raman mosaic imaging screening

Microplastics (MPs) have been detected in various tissues, yet evidence regarding the relatively isolated nucleus pulposus (NP) remains limited. This study investigated MPs in NP tissues from 51 patients undergoing lumbar disc herniation (LDH) surgery in Wuhan, China. Samples underwent chemical digestion and filtration, followed by candidate-particle screening using an operator-assisted micro-Raman spectroscopy mosaic imaging workflow and targeted Raman spectral assignment. Microplastic-sized polymer particles were Raman-assigned in five patients, including polyurethane foam, poly (propylene glycol), poly (ethylene-co-vinyl acetate), polyacrylate rubber, and poly (ethylene-co-propylene). A graphite particle was also detected in one additional patient. Specifically, nine particles ranging from 37 to 280 μm were detected across six patients; notably, most were smaller than 100 μm. To reduce false-positive assignments, procedural blanks and five known surgical materials were analyzed, and particles matching these sampled materials were excluded. This study provides preliminary evidence of particulate contaminants in NP tissue, demonstrating the feasibility of detection in this understudied anatomical compartment and establishing a methodological foundation for future investigations.