Basavaraju, D. M. | Search bioRxiv

bioRxiv2026

Polyisobutylene Micro/Nanoplastics Induce Multi-System Toxicity, Intestinal Barrier Dysfunction, and Neurodegeneration in Drosophila melanogaster

Micro/nanoplastics (MNPs) are increasingly recognized as a persistent environmental contaminant of concern, yet polyisobutylene (PIB), an industrially significant polymer used as industrial sealants, adhesives, cable insulation, lubricant additives, and chewing gum bases, remains poorly studied relative to more commonly studied plastics such as polyethylene terephthalate (PET), polystyrene (PS), and polyethylene (PE). This study investigated the multisystem toxicological effects of chronic dietary exposure to PIB-MNPs in Drosophila melanogaster. PIB-MNPs (> 5 micron) were synthesized via the solvent evaporation method and characterized using scanning electron microscopy (SEM) and Fourier Transform Infrared spectroscopy (FTIR), confirming successful synthesis. Flies were chronically exposed to PIB-MNPs (1, 2, or 3 mg) alongside an SDS control and a water control to 50 mg of yeast over 21 days, with toxicological outcomes assessed via survival analysis, climbing assays, fluorescence brain imaging, fertility/fecundity assays, the Smurf gut-permeability assay, Ellman's AChE activity assay, and RT-qPCR analysis of Stat92E expression, a marker of inflammation. Chronic exposure to PIB-MNPs reduced survival, with females exhibiting markedly greater susceptibility than males. Exposure progressively impaired locomotor performance and induced brain vacuolization suggestive of neurodegeneration, peaking at day 15. AChE activity declined in a concentration-dependent manner by day 21. Female fecundity, egg-hatching rate, and ovarian egg-chamber maturation were significantly reduced, while male gonadal cyst cell numbers remained largely unaffected. PIB-MNPs exposure also induced a positive Smurf phenotype, indicating compromised intestinal barrier integrity and upregulated Stat92E expression, consistent with activation of a systemic stress response. Notably, several endpoints showed non-monotonic, concentration-independent trends, suggesting particle aggregation may influence effective bioavailability. Collectively, these findings establish PIB-MNPs as a multi-system toxicant in Drosophila.

cell biology↗

bioRxiv2024

Exploring the link between extended red blood cell parameters and platelet indices in voluntary blood donors

BackgroundAs regular blood donors are prone to iron deficiency, importance of extended red blood cell (eRBC) parameters in identifying donors with depleted iron stores was investigated. Thrombocytosis has been well documented in patients affected with IDA. Thus, significance of eRBC parameters in identifying iron deficiency associated thrombocytosis was also examined in this cohort. MethodsBlood samples were collected in EDTA tubes from consenting donors for analyses of routine haematological and eRBC parameters. Serum samples were isolated for estimation of iron parameters. ResultsIron deficient donors had significantly altered eRBC parameters. Among them, Ret-He with a cut-off of [≥]32 pg had high AUC (0.822) and showed relatively high sensitivity & specificity in detecting iron deficiency. Combination of Ret-He with CCI increased sensitivity & specificity to 90.6% and 98.2%, in detection of donors affected with iron restricted erythropoiesis. This cohort had increased platelet counts, which showed significant association with Ret-He ({beta}= -0.373), RBC-He ({beta}= -0.384), CCI ({beta}= 0.384), Hypo-He ({beta}=0.494) and Micro-R ({beta}= 0.299). Elevated platelet counts also showed significant correlations with these eRBC parameters, which was absent in iron replete donors. ConclusionseRBC parameters are sensitive indicators of non-anaemic iron deficiency, which may be enhanced by combining them. Their significant association with elevated platelet counts in iron deficient donors, highlights their importance in reflecting iron deficiency associated thrombocytosis. Impact StatementThe present study discusses utility of eRBC parameters in detecting non-anaemic iron deficiency, in regular voluntary blood donors. Previous reports have investigated the importance of these parameters in identifying IDA in blood donors. The present study is the first one which indicates combining different eRBC parameters such as Ret-He and CCI increases their accuracy of detection. They were also significantly associated with elevated platelet counts in iron deficient donors, which was absent in iron replete individuals. This link between eRBC parameters and higher platelet counts in healthy donors affected with non-anaemic iron deficiency has not been reported before.

bioinformatics↗