Co-exposure to nanoplastics and acetaminophen causes skeletal dysplasia and behavioral abnormalities in zebrafish.

Nanoplastics (NPs) and acetaminophen (APAP) are thought to be common contaminants and are invariably detected in the environment. Despite the increasing awareness of their toxicity to humans and animals, the embryonic toxicity, skeletal development toxicity, and mechanism of action of their combined exposure have not been clarified. This study was performed to investigate whether combined exposure to NPs and APAP induces abnormal embryonic and skeletal development in zebrafish and to explore the potential toxicological mechanisms. All zebrafish juveniles in the high-concentration compound exposure group showed some abnormal phenomena such as pericardial edema, spinal curvature, cartilage developmental abnormality and melanin inhibition together with a significant downward trend in body length. Behavioral data also implicated that the exposure of APAP alone, as well as the co-exposure of NPs and APAP, caused a depression in the total distance, swimming speed and the maximum acceleration. Furthermore, real-time polymerase chain reaction analysis showed that compared with exposure alone, the expression level of genes related to osteogenesis, runx2a, runx2b, Sp7, bmp2b and shh was significantly reduced with compound exposure. These results suggest that the compound exposure of NPs and APAP has adverse impacts on zebrafish embryonic development and skeletal growth.

Generation of Simulated "Natural" Nanoplastics from Polypropylene Food Packaging as the Experimental Standard.

Current toxicology research on nanoplastics (NPs) generally uses commercial spherical NPs. However, the physicochemical characteristics of commercial NPs are significantly different from those of NPs formed under natural conditions, possibly affecting the validity of the results. In analytical chemistry, a reference sample is selected such that its physicochemical properties are as similar as possible to the target. Therefore, a simulated "natural" NP synthesized in the laboratory that closely resembles naturally derived NPs would be used as an authentic standard. Here, we established the assay of scanning electron microscope (SEM)-particle size distribution analyzer (PSDA)-surface-enhanced Raman scattering (SERS) to detect NPs and prepared simulated "natural" NPs from polypropylene food packaging material using a method that mimics natural conditions. Nanofiltration was used to isolate three sets of simulated NPs with particle sizes ranging from 50-100 nm, 100-200 nm, and 200-400 nm. These simulated "natural" NPs were more similar to naturally occurring counterparts when compared with commercial NPs. These new standard NPs, which should be scalable for large-scale use, will improve the accuracy, reliability, and translatability of toxicological studies of NPs.

Dual-pH Sensitive Charge-Reversal Drug Delivery System for Highly Precise and Penetrative Chemotherapy.

PURPOSE: The complex physiological barriers impose extremely conflicting demands on systemic drug delivery, so both particle size and surface charge of the nanoplatforms become vital factors. As a carbon-based nanomaterial with excellent optical properties, carbon dots are not suitable for direct systemic transport in vivo, which limits their application in the field of biomedical imaging, especially in the areas of diagnosis and cancer treatment. Liposomes have been developed as universal nanocarriers for various drugs. In this study, we aimed to build a highly precise and penetrative drug delivery system (DDS) using carbon dots encapsulated by liposomes. METHODS: Carbon dots (CDs) were synthesized by the hydrothermal method using citric acid and ethylenediamine. Furthermore, simian virus 40 large T-antigen derived the nuclear targeting sequence (NLS) was bonded on the surface of CDs to obtain CDs-NLS. The antitumor drug doxorubicin was loaded onto the CDs-NLS through an acid-labile hydrazine bond to obtain DOX@CDs. Finally, DOX@CDs were encapsulated in aqueous centers of folate-coated and pH-sensitive liposomes, named pHSL-FA. RESULTS: In this paper, a nucleus-targeted nanocomposite (DOX@CDs), which bonds with the nuclear targeting sequence (NLS) and the anticancer drug doxorubicin (DOX), has physicochemical properties of particle size of about 3.8 nm, zeta potential of +31.8 mV and high quantum yield of 64.53%. The negatively charged folate-coated and pH-sensitive liposomes (pHSL-FA) are used as a carrier to reverse the surface charge of DOX@CDs. Compared to free DOX@CDs, pHSL-FA show higher tumor accumulation in 4 T1 tumor-bearing mice and further improve cytotoxicity to tumor cells. CONCLUSIONS: This work proposes a unique nanomedical approach that enables the precise delivery of chemotherapy drugs and significantly reduces side effects, which is promising for clinical translation.

Sensory Quality Evaluation of Korla Pear from Different Orchards and Analysis of Their Primary and Volatile Metabolites.

Metabolites play vital roles in shaping the quality of fresh fruit. In this study, Korla pear fruit harvested from twelve orchards in South Xinjiang, China, were ranked in sensory quality by fuzzy logic sensory evaluation for two consecutive seasons. Then, gas chromatography-mass spectrometry (GC-MS) was applied to determine the primary metabolites and volatile compounds. Sensory evaluation results showed that the panelists were more concerned about 'mouth feel' and 'aroma' than about 'fruit size', 'fruit shape' and 'peel color'. In total, 20 primary metabolites and 100 volatiles were detected in the pear fruit. Hexanal, (E)-2-hexenal, nonanal, d-limonene, (Z)-3-hexen-1-yl acetate and hexyl acetate were identified as the major volatile compounds. Correlation analysis revealed that l-(+)-tartaric acid, hexanoic acid, trans-limonene oxide and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate were negatively correlated with sensory scores. Furthermore, OPLS-DA results indicated that the fruit from three orchards with lower ranks in quality could be distinguished from other samples based on the contents of l-(+)-tartaric acid and other eight metabolites, which were all associated with 'mouth feel' and 'aroma'. This study reveals the metabolites that might be closely associated with the sensory quality attributes of Korla pear, which may provide some clues for promoting the fruit quality in actual production.

The efficient profiling of serum N-linked glycans by a highly porous 3D graphene composite.

In this work, an enrichment approach for the profiling of N-linked glycans was developed by utilizing a highly porous 3D graphene composite fabricated from graphene oxide nanosheets and a phenol-formaldehyde polymer via graphitization and KOH activation. In tailoring the large surface area (ca. 2213 m2 g-1) and 3D-layered mesoporous structure, the 3D graphene composite demonstrated not only high efficiency in glycan enrichment but also the size-exclusion effect against residual protein interference. For a standard protein ovalbumin digest, 26 N-linked glycans were identified with good repeatability, and the detection limit was as low as 0.25 ng µL-1 with the identification of 13 N-linked glycans (S/N > 10). When the mass ratio of the ovalbumin digest to the interfering proteins, i.e., bovine serum albumin and ovalbumin was 1 : 2000 : 2000, 18 N-linked glycans could still be detected with sufficient signal intensities. From a 60 nL minute complex human serum sample, up to 53 N-linked glycans with S/N > 10 were identified after the 3D graphene enrichment, while only 20 N-linked glycans were identified by the porous graphitized carbon material used for comparison. In addition, the application of the 3D graphene composite in profiling the up-regulated and down-regulated N-linked glycans from the real clinical serum samples of ovarian cancer patients confirmed the potential of the 3D graphene composite for analyzing minute and complicated biological samples.

Towards Identifying and Reducing the Bias of Disease Information Extracted from Search Engine Data.

The estimation of disease prevalence in online search engine data (e.g., Google Flu Trends (GFT)) has received a considerable amount of scholarly and public attention in recent years. While the utility of search engine data for disease surveillance has been demonstrated, the scientific community still seeks ways to identify and reduce biases that are embedded in search engine data. The primary goal of this study is to explore new ways of improving the accuracy of disease prevalence estimations by combining traditional disease data with search engine data. A novel method, Biased Sentinel Hospital-based Area Disease Estimation (B-SHADE), is introduced to reduce search engine data bias from a geographical perspective. To monitor search trends on Hand, Foot and Mouth Disease (HFMD) in Guangdong Province, China, we tested our approach by selecting 11 keywords from the Baidu index platform, a Chinese big data analyst similar to GFT. The correlation between the number of real cases and the composite index was 0.8. After decomposing the composite index at the city level, we found that only 10 cities presented a correlation of close to 0.8 or higher. These cities were found to be more stable with respect to search volume, and they were selected as sample cities in order to estimate the search volume of the entire province. After the estimation, the correlation improved from 0.8 to 0.864. After fitting the revised search volume with historical cases, the mean absolute error was 11.19% lower than it was when the original search volume and historical cases were combined. To our knowledge, this is the first study to reduce search engine data bias levels through the use of rigorous spatial sampling strategies.

Aminobenzofuran-fused rhodamine dyes with deep-red to near-infrared emission for biological applications.

Aminobenzofuran-fused rhodamine dyes (AFR dyes) containing an amino group were constructed by an efficient condensation based on 3-coumaranone derivatives. AFR dyes exhibited significantly improved properties, including deep-red and near-infrared emissions, a large Stokes shift, good photostability, and wide pH stability. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium assay experiments show that these AFR dyes are biocompatible for their low cytotoxicity to both A549 and HeLa cells. Cell imaging data reveal that AFR1, AFR1E, and AFR2 are mainly located in the mitochondria, while AFR3 is a lysosome tracker. As far as we know, NIR AFR3 is the longest fluorescent rhodamine derivative containing the amino group. These amino group-containing AFR dyes hold great potential in fluorogenic detection, biomolecule labeling, and cell imaging.

Pharmacokinetics and tolerability of paliperidone palmitate injection in Chinese subjects.

OBJECTIVE: The objective of this study was to characterize the pharmacokinetics of 25, 100, and 150 mg equivalents (eq.) of paliperidone long-acting injection in Chinese subjects with schizophrenia. METHODS: This was an open-label, randomized, parallel group, multicenter study. A total of 48 patients were randomized in a 1:1:1 ratio to one of three groups. Sequential blood samples were collected immediately before injection on day 1 and up to 210 days after the first injection. The plasma paliperidone concentrations were determined by a validated high-performance liquid chromatography/tandem mass spectrometry method. RESULTS: A total of 47 patients received at least one injection of the study medication, and 43 completed the study. The pharmacokinetic (PK) parameters, such as time to maximum concentration, t1/2, and CL/F, were comparable across the three treatment groups (p = 0.935, 0.349, and 0.794, respectively). The differences in maximum plasma concentration, AUC (035 days), AUC (0-210 days), and AUC (0-∞) were significant (p < 0.001) and dose proportional. The inter-individual variation of PK parameters was large. The most frequent treatment-emergent adverse events were prolactin level increasing, injection site pain, tremor, dry mouth, and constipation. CONCLUSIONS: The pharmacokinetics of paliperidone palmitate are linear with respect to time in Chinese subjects with schizophrenia at injections from 25 to 150 mg eq.

Effect of chitosan/dioleyl phosphatidyl ethanolamine - Baicalein nanohydrogel in the treatment of rat with periodontitis.

Objective: this work aimed to investigate the effectiveness of chitosan (CS)/dioleyl phosphatidyl ethanolamine (DOPE) - baicalein (CS/DOPE-BAE) nanohydrogel as a novel drug delivery system for the treatment of periodontitis in rats. Materials and methods: the CS/DOPE-BAE nanohydrogel was synthesized and characterized for its morphology, particle size (PS), drug loading, and release properties. A rat periodontitis model was established, and the rats were randomly assigned to four groups, receiving treatment of normal saline, CS/DOPE blank nanohydrogel, baicalein solution, and CS/DOPE-BAE nanohydrogel through local injection, respectively. Clinical symptoms, periodontal tissue morphology, and the levels of interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α), and IL-10 in the periodontal tissue were observed and compared. Results: the CS/DOPE-BAE nanohydrogel exhibited a spherical shape with a PS of approximately 200 nm and a drug loading of 8.6 %. It demonstrated excellent sustained-release properties. The group treated with CS/DOPE-BAE nanohydrogel showed significant improvement in clinical symptoms, such as reduced gingival redness and bleeding in rats, decreased inflammatory cell infiltration, and weakened fibroblast proliferation in the periodontal tissue. Additionally, IL-1ß and TNF-α levels were downregulated, while IL-10 level was elevated. Conclusion: the CS/DOPE-BAE nanohydrogel was an effective baicalein delivery system that can inhibit the progression of periodontitis, improve the inflammatory response in periodontal tissue, and deliver promising therapeutic effects.

A retrospective study on iRoot BP Plus full pulpotomy for primary molars with partial irreversible pulpitis.

OBJECTIVES: This study aimed to observe the outcomes of iRoot BP Plus full pulpotomy in primary molars with partial irreversible pulpitis retrospectively. METHODS: Collect 102 cases of primary molars with partial irreversible pulpitis undergoing iRoot BP Plus full pulpotomy from January 2019 to August 2023, with a follow-up period of 24-47 months. Based on the presence of irreversible pulpitis symptoms before surgery, the included cases will be divided into asymptomatic group (n=53) and symptomatic group (n=49). Observe the clinical and imaging success rates of both groups. RESULTS: Clinical success rates were 96.2% and 97.9% in asymptomatic and symptomatic groups, and radiographic success rates were 96.2% and 93.9% respectively. CONCLUSIONS: iRoot BP Plus full pulpotomy can be used for the treatment of primary molars with partial irreversible pulpitis under an enhanced pulpotomy protocol.

Rhein and hesperidin nanoparticles remodel tumor immune microenvironment by reducing CAFs and CCL2 secreted by CAAs for efficient triple-negative breast cancer therapy.

In triple-negative breast cancer (TNBC), the tumor immune microenvironment (TIME) is a highly heterogeneous ecosystem that exerts indispensable roles in tumorigenesis and tumor progression. Cancer-associated fibroblasts (CAFs) and cancer-associated adipocytes (CAAs) are the main matrix components in the TIME of TNBC. CAFs mediate the edesmoplastic response, which is a major driver of the immunosuppressive microenvironment to promote tumor growth. In addition, CAAs, a type of tumor-educated adipocyte, participate in crosstalk with breast cancer and are capable of secreting various cytokines, adipokines and chemokines, especially C-C Motif Chemokine Ligand 2 (CCL2), resulting in changes of cancer cell phenotype and function. Therefore, how to treat tumors by regulating the CAFs and the secretion of CCL2 by CAAs in TIME is investigated here. Our research group previously found that rhein (Rhe) has been identified as effective against CAFs, while hesperidin (Hes) could effectively diminish CCL2 secretion by CAAs. Inspired by the above, we developed unique PLGA-based nanoparticles loaded with Rhe and Hes (RH-NP) using the emulsion solvent diffusion method. The RH-NP particles have an average size of 114.1 ± 0.98 nm. RH-NP effectively reduces CAFs and inhibits CCL2 secretion by CAAs, promoting increased infiltration of cytotoxic T cells and reducing immunosuppressive cell presence within tumors. This innovative, safe, low-toxic, and highly effective anti-tumor strategy could be prospective in TNBC treatment.

Hesperidin PLGA nanoparticles potentiate the efficacy of aPD-1 in treating triple negative breast cancer by regulating CCL2 and ADPN expression in cancer-associated adipocytes.

Triple negative breast cancer (TNBC) represents a heterogeneous subtype of breast cancer characterized by an unfavorable prognosis due to its aggressive biology. Cancer-associated adipocytes (CAAs) play an active role in tumor development, invasion and metastasis, and response to treatment by secreting various cytokines. CAAs secrete CCL2 and ADPN which significantly affect the efficacy of aPD-1 in treating breast cancer. Our recent research has demonstrated that Hesperidin, a natural phenolic compound, significantly inhibits CCL2, elevates ADPN secreted by CAAs in vitro and in vivo, remodels the immune microenvironment, and potentiates the efficacy of aPD-1 in triple-negative breast cancer. We used Oil red staining, Bodipy 493/503 staining and quantitative real-time PCR to verify the formation of CAAs. ELISA was used to detect levels of CCL2, ADPN secreted by CAAs. Changes in the number of immune cells in mouse tumor tissues were detected using flow cytometry and immunofluorescence. Our data suggest that Hesperidin PLGA nanoparticles significantly reduced CCL2 and increased ADPN secreted by CAAs, which concurrently decreased the recruitment of M2 macrophages, Tregs and MDSCs while increased the infiltration of CD8+T cells, M1 macrophages and DCs into tumor, thus significantly potentiated the efficacy of aPD-1 in vivo. This study provides a new combined strategy for the clinical treatment of triple-negative breast cancer by interfering with CCL2, ADPN secreted by CAAs to enhance the efficacy of immunotherapy.

Multifunctional pH-responsive hydrogel dressings based on carboxymethyl chitosan: Synthesis, characterization fostering the wound healing.

Antibiotic abuse is increasing the present rate of drug-resistant bacterial wound infections, producing a significant healthcare burden globally. Herein, we prepared a pH-responsive CMCS/PVP/TA (CPT) multifunctional hydrogel dressing by embedding the natural plant extract TA as a nonantibiotic and cross-linking agent in carboxymethyl chitosan (CMCS) and polyvinylpyrrolidone (PVP) to prompt wound healing. The CPT hydrogel demonstrated excellent self-healing, self-adaptive, and adhesion properties to match different wound requirements. Importantly, this hydrogel showed pH sensitivity and exhibited good activity against resistant bacteria and antioxidant activity by releasing TA in case of bacterial infection (alkaline). Furthermore, the CPT hydrogel exhibited coagulant ability and could rapidly stop bleeding within 30 s. The biocompatible hydrogel effectively accelerated wound healing in a full-thickness skin defect model by thickening granulation tissue, increasing collagen deposition, vascular proliferation, and M2-type macrophage polarization. In conclusion, this study demonstrates that multifunctional CPT hydrogel offers a candidate material with potential applications for infected skin wound healing.

Determination of no observable effect level of nanoplastics on intestinal flora.

The risk of human exposure to nanoplastics (NPs) is increasing due to the incomplete decomposition and accumulation of plastic debris in the environment. Dietary intake is the most common way for human body to ingest NPs. NPs cannot degrade in vivo and will accumulate in multiple tissues, which result in various tissue damages. Although numerous studies have focused on evaluating the influences of exposure to NPs, the exposure amounts investigated were much higher than the actual exposure level in human daily life. Therefore, it is necessary to evaluate the hazards of exposure to low-dose NPs. Intestinal flora is a generally recognized sensitive indicator for NPs exposure, so determining a safe threshold to intestinal flora can represent the maximal no-effective dose for the human body of NPs exposure. Based on these information, mice were exposed to NPs at concentrations of 0, 0.001, 0.005, 0.01 and 0.1 mg kg-1·BW, respectively. The composition changes of the intestinal flora were investigated after exposing 28 days. The obtained consequences indicated that 0.01 mg kg-1·BW was the maximal no-effective dose to intestinal flora. This study provided a clear safe threshold for investigating the potential adverse effects of low-dose NPs exposures on human health.

Interaction of polystyrene nanoplastics with human fibrinogen.

Nanoplastics are an emerging environmental contaminant that can penetrate biological barriers to enter the bloodstream and risk human health. In this context, nanoplastics are likely to interact with proteins in the blood to possibly affect protein structure and function and consequently induce biological effects. Here we report that polystyrene (PS), PS-NH2, and PS-COOH nanoplastics disrupt the structure of human fibrinogen (HF) in a dose-dependent manner, as revealed by UV-vis and fluorescence spectroscopy. All three nanoplastics interacted with HF in a similar way, with PS-NH2 having the greatest effect on HF structure. Furthermore, fibrinogen polymerization experiments demonstrated that nanoplastics have the potential to promote blood coagulation, with PS-NH2 again having a stronger effect. Collectively, these results provide insights into the interactions occurring between nanoplastics and HF, the likely transport and fate of nanoplastics in organisms, and their potential pathophysiological consequences.

Brassinosteroids alleviate nanoplastic toxicity in edible plants by activating antioxidant defense systems and suppressing nanoplastic uptake.

As emerging pollutants of global concern, absorbed nanoplastics might have negative impacts on plant development and nutrient uptake, thereby decreasing yields. If nanoplastics are transferred to the edible parts of plants, they may pose a threat to human health when large quantities are ingested. While nanoplastic-induced phytotoxicity is attracting increasing attention, little is known about how to inhibit nanoplastic accumulation in plants and reduce the subsequent adverse effects. Here we investigated the absorption and accumulation of polystyrene nanoplastics (PS-NPs) in different plant species and the role of brassinosteroids in alleviating PS-NP toxicity. Brassinosteroids inhibited accumulation of PS-NPs in tomato fruit and reversed PS-NP-induced phytotoxicity to promote plant growth and increase fresh weight and plant height. Brassinosteroids also reversed the induction of aquaporin-related genes by PS-NPs including TIP2-1, TIP2-2, PIP2-6, PIP2-8, PIP2-9, SIP2-1, and NIP1-2, providing a potential stress mechanism by which PS-NPs accumulate in the edible parts and targets for inhibition. In transcriptomic analyses, brassinosteroids enhanced fatty acid and amino acid metabolism and synthesis. In conclusion, exogenous application of 50 nM brassinosteroids alleviated the adverse effects of PS-NPs on plants, and exogenous application of brassinosteroids might be an effective means to minimize PS-NP-induced phytotoxicity.

Nanoplastic-induced vascular endothelial injury and coagulation dysfunction in mice.

Nanoplastics are the persistent pollutants in a variety of environments, representing a potential threat to human health. Notably, plastic particles have been detected in sample of human bloodstream. It is thus significant to investigate the effects of nanoplastics on the cardiovascular system owing to its ease transfer through the bloodstream to other organs. However, few studies have been performed to evaluate the cardiovascular toxicity of nanoplastics. Herein, we pursued to investigate the adverse cardiovascular impacts of polystyrene (PS), PS-NH2 and PS-COOH nanoplastics on mice. Experimental results demonstrated that the exposure to these nanoplastics could result in structural damage of vascular endothelial cells and inflammatory response. Moreover, it was found out that the dysfunctions of coagulation and prethrombotic state were caused by nanoplastics, which could be ascribed to the activation of JAK1/STAT3/TF signaling pathway. In summary, results clearly indicated that nanoplastic exposure lead to vascular toxicity to mice, which serves as a basis for future studies about the potential physiological threat of nanoplastics to humans.

A suturable biohydrogel with mechanical matched property based on coating chitosan and polyethylene glycol shell for tissue patching.

The mechanical mismatch between soft hydrated tissues and sutures has become a common negative impact on wound healing process. A novel method of coating multilayer polymer shells is thus reported to improve the mechanical performance of hydrogel sutures. It is suitable for tissue patching and shows advantages of convenient, efficient, and biosafety. Specifically, a precursor hydrogel (Cu@CMC) consisted of carboxymethyl chitosan and copper modified by carbon dots was used as the inner sheath, and then bonding the precursor hydrogel sheath with toughening polyethylene glycol network by anchoring sites composited from rigid chitosan shell integrated a whole structure. Subsequently, the whole system was soaked with EtOH, and rapid dehydration of EtOH was used to accelerate the entanglement process between the two coatings by constricting the molecular chains. Finally, an ideal suture (Cu-fiber) with both toughness and rigidness was obtained. The data showed that the tensile strength and biosafety of the hydrogel sutures prepared by the new strategy were significantly improved, and the skin, liver and vessel of rodents can be sutured without secondary damage. Moreover, it can inhibit inflammation response and promote the healing process of skin wound, indicating that the Cu-fiber will become a great candidate for tissue patching.

Preparation and Quality Evaluation of Honokiol Nanoparticles Using a New Polysaccharide Polymer as its Carrier.

OBJECTIVE: To improve the solubility of Honokiol (HNK), Honokiol nanoparticles (HNK-NPs) were prepared using a new biodegradable polysaccharide polymer as its carrier. METHODS: HNK-NPs were prepared by hydrophilic polymer coagulation method, and the processing parameters were optimized according to average particle size and PDI by a single factor experiment. The morphology of the optimized nanoparticles was investigated by TEM, and the in vitro release was carried out to evaluate the optimized HNK-NPs. RESULTS: The encapsulation efficiency and drug loading of the HNK-NPs were 77.75 ± 2.63% and 13.46 ± 0.39%, respectively. The obtained nanoparticles of HNK-NPs were spherical-like under the electron microscope with a mean particle size of 198.50 ± 0.01 nm and a Zeta potential of -52.60 ± 1.00 mV. The in vitro release results showed that the cumulative release rates of nanoparticles were 48.28 ± 9.80% and 81.12 ± 4.35% within 2 h and 8 h, respectively, showing a stable release behavior. The average particle size and PDI of HNK-NPs solution prepared by the hydrophilic polymer condensation method had no obvious change at 72h. CONCLUSION: HNK-NPs were successfully prepared by the phase separation method. This new polysaccharide polymer should be an ideal carrier to help improve the solubility of HNK.

Microplastics in plateau agricultural areas: Spatial changes reveal their source and distribution characteristics.

The Huangshui catchment on the northeastern Qinghai-Tibet Plateau (QTP) was selected as the study area to investigate the abundance, distribution characteristics, and influencing factors of microplastics (MPs) in surface agricultural soils (0-20 cm). The MP levels ranged from 6 to 444 items/kg, with an average of 86 items/kg. The relative abundance of small-sized MPs (<2 mm) was higher than that of large-sized MPs (2-5 mm). Polyethylene was the most common, and residual mulching film in farmland was the main source of MPs. The spatial distribution characteristics of MPs were analyzed through inverse distance weight interpolation, and MP abundance in agricultural soils in neighboring urban areas was significantly higher than that in other areas. Further analysis found that population density was significantly positively correlated with MP abundance (R2 = 0.9090, p < 0.01), indicating that human activities play a key role in MP pollution even in remote areas. In addition, the effects of irrigation, land use type, and soil physicochemical properties on the abundance of MPs were analyzed. Atmospheric transport and irrigation with surface water contribute to soil MP pollution. The direct effects of soil properties on MP abundance are still largely unclear, requiring further studies.