The Roles of Periodontal Bacteria in Atherosclerosis.

Atherosclerosis (AS) is an inflammatory vascular disease that constitutes a major underlying cause of cardiovascular diseases (CVD) and stroke. Infection is a contributing risk factor for AS. Epidemiological evidence has implicated individuals afflicted by periodontitis displaying an increased susceptibility to AS and CVD. This review concisely outlines several prevalent periodontal pathogens identified within atherosclerotic plaques, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. We review the existing epidemiological evidence elucidating the association between these pathogens and AS-related diseases, and the diverse mechanisms for which these pathogens may engage in AS, such as endothelial barrier disruption, immune system activation, facilitation of monocyte adhesion and aggregation, and promotion of foam cell formation, all of which contribute to the progression and destabilization of atherosclerotic plaques. Notably, the intricate interplay among bacteria underscores the complex impact of periodontitis on AS. In conclusion, advancing our understanding of the relationship between periodontal pathogens and AS will undoubtedly offer invaluable insights and potential therapeutic avenues for the prevention and management of AS.

Rational Design of Conducting Polymer-Derived Tubular Carbon Nanoreactors for Enhanced Enzyme-like Catalysis and Total Antioxidant Capacity Bioassay Application.

The design of void-confined tubular nanostructures has aroused significant interest for catalytic applications because of their distinct microenvironment to modulate the reaction kinetics. Herein, we propose a facile wrapping-pyrolysis strategy to confine Fe0 nanoparticles (Fe NPs) inside N-doped carbon nanotubes (Fe@NC NTs) derived from Fe2O3@polypyrrole (PPy) core-sheath nanofibers (NFs). The resultant Fe@NC NTs can act as efficient enzyme mimics and exhibit a significantly higher peroxidase (POD)-like catalytic activity than unconfined Fe NPs and bare NC NTs. Kinetic experiments demonstrate that the optimized void structure benefits the affinity with the POD substrates and achieves excellent catalytic efficiency. The mechanism study reveals that the generation of •OH from H2O2 endows Fe@NC NTs with excellent POD-like performance. Furthermore, we develop a total antioxidant capacity (TAC) sensing platform on account of this efficient POD-like system, expanding their applications in the field of food safety and human healthcare.

Synthesis and application of smart gel material modified silica microspheres for pH-responsive hydrophilicity in liquid chromatography.

Inspired by porous smart gel materials, we designed pH-responsive polymer-modified silica microspheres as liquid chromatography stationary phase materials by a one-step strategy. The free radicals generated by the oxidation of dopamine are used to initiate the cross-linking polymerization of functional monomers. At the same time, the good adhesion of dopamine enables the polymer to be modified on silica. The hydrophilicity of this new stationary phase can change in response to the pH of the mobile phase and the stationary phase has weaker hydrophilicity under acidic (pH = 3.78) mobile phase conditions and stronger hydrophilicity under neutral mobile phase conditions. The hydrophilicity difference of the stationary phase leads to the selectivity difference in separation. To evaluate the chromatographic performance of this new stationary phase, 10 oligosaccharides and 9 nucleosides/bases were separated on this stationary phase. This paper will provide good guidance for us to achieve more pH-responsive hydrophilic/hydrophobic stationary phases in the future.

The roles of osteocytes in alveolar bone destruction in periodontitis.

Periodontitis, a bacterium-induced inflammatory disease that is characterized by alveolar bone loss, is highly prevalent worldwide. Elucidating the underlying mechanisms of alveolar bone loss in periodontitis is crucial for understanding its pathogenesis. Classically, bone cells, such as osteoclasts, osteoblasts and bone marrow stromal cells, are thought to dominate the development of bone destruction in periodontitis. Recently, osteocytes, the cells embedded in the mineral matrix, have gained attention. This review demonstrates the key contributing role of osteocytes in periodontitis, especially in alveolar bone loss. Osteocytes not only initiate physiological bone remodeling but also assist in inflammation-related changes in bone remodeling. The latest evidence suggests that osteocytes are involved in regulating bone anabolism and catabolism in the progression of periodontitis. The altered secretion of receptor activator of NF-κB ligand (RANKL), sclerostin and Dickkopf-related protein 1 (DKK1) by osteocytes affects the balance of bone resorption and formation and promotes bone loss. In addition, the accumulation of prematurely senescent and apoptotic osteocytes observed in alveolar bone may exacerbate local destruction. Based on their communication with the bloodstream, it is noteworthy that osteocytes may participate in the interaction between local periodontitis lesions and systemic diseases. Overall, further investigations of osteocytes may provide vital insights that improve our understanding of the pathophysiology of periodontitis.

Bioaccumulation investigation of bisphenol A in HepG2 cells and zebrafishes enabled by cobalt magnetic polystyrene microsphere derived carbon based magnetic solid-phase extraction.

A magnetic solid-phase extraction (MSPE) technique coupled with high performance liquid chromatography (HPLC) was developed and used for bioaccumulation investigation of bisphenol A (BPA) in HepG2 cells and zebrafishes. Cobalt magnetic polystyrene microsphere derived carbon (C-Co@PST) as an adsorbent was prepared by in situ polymerization reaction and further annealing treatment. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy and X-ray diffraction were employed to confirm successful synthesis of C-Co@PST. A series of extraction parameters including the amount of the sorbent, the type of elute, extraction time and elution time were investigated to achieve high extraction efficiency. C-Co@PST based MSPE combined with HPLC was successfully established for bioaccumulation research of BPA in living creatures. It was found that the bioconcentration values of BPA in HepG2 cells underwent an increase, then a decrease, and finally reached an equilibrium level of 11.60 µg kg-1 at 8 h. The concentration of BPA in zebrafishes increased ranging from 6.05 µg kg-1 to 31.84 µg kg-1 over a culture time from 1 h to 12 h. Furthermore, linear and exponential models were employed to analyse the bioconcentration variation of BPA in organisms over the exposure time. Mathematical models have been developed to predict the transfer characteristics of BPA.

Removal of strontium from simulated low-level radioactive wastewater by nanofiltration.

The performance of different nanofiltration (NF) membranes for the treatment of strontium-containing radioactive wastewater was investigated. The effects of the initial strontium concentration, solution pH and complexation phenomena on strontium removal were described. For all the three membranes, the strontium rejection increased with decreasing initial strontium concentration. Meanwhile, the strontium rejection was minimum at the membrane isoelectric point (pH 5) primarily due to decreased co-ion electrostatic repulsion. In the presence of a complexing agent (polyacrylic acid or ethylenediamine tetraacetic acid disodium salt), the strontium rejection was generally higher than those obtained without a complexing agent for NF 270 and XN 45. Membrane cleaning experiments were also conducted to recover the performance of the membranes, which exhibited degradation during long-time filtration. The performance of the membranes after cleaning was close to that of the virgin membranes, especially for XN 45, whose recovery percentage was nearly 100%.

Conjugation to 10 kDa Linear PEG Extends Serum Half-Life and Preserves the Receptor-Binding Ability of mmTRAIL with Minimal Stimulation of PEG-Specific Antibodies.

The poor in vivo potencies of most therapeutic proteins might be attributed to their short serum half-lives. PEGylation is a well-established method and has been clinically proven to improve pharmacokinetics. mmTRAIL exhibited supercytotoxicity in a variety of tumor cells, but its serum half-life was less than 10 min in mice. Here, mmTRAIL-5K, mmTRAIL-10K, and mmTRAIL-20K were produced by N-terminus-specific PEGylation of mmTRAIL with 5, 10, or 20 kDa mPEG, respectively. The particle sizes of mmTRAIL-5K, mmTRAIL-10K, and mmTRAIL-20K were 9.09 ± 2.76, 12.62 ± 4.05, and 15.68 ± 4.95 nm, which were higher than the threshold (∼7 nm) of renal clearance. Accordingly, mmTRAIL-5K exhibited a serum half-life of 30 min only 3 times longer than that of mmTRAIL. However, both mmTRAIL-10K and mmTRAIL-20K exhibited similar serum half-lives ranging from 350 to 400 min, indicating that PEGylation with 10 or 20 kDa mPEG significantly improved the pharmacokinetics of mmTRAIL. However, death receptor binding of mmTRAIL-20K was reduced 5- to 8-fold, resulting in a 3-fold reduction of cytotoxicity. Additionally, repeated administration of mmTRAIL-20K elicited both mPEG-specific IgG and IgM antibody responses in rats. In contrast, the receptor binding and cytotoxicity of mmTRAIL-10K were similar to those of mmTRAIL. Repeated administration of mmTRAIL-10K did not obviously stimulate mPEG-specific antibody responses in rats and rhesus monkeys. Of the three PEGylated mmTRAIL analogues, mmTRAIL-10K exerted the greatest tumor suppression in mice bearing human tumor xenografts. These results demonstrated that conjugation of mmTRAIL to 10 kDa mPEG was better than that to 5 or 20 kDa mPEG for enhancing antitumor effects.

Strongly coupled CeO2/Co3O4/poly(3,4-ethylenedioxythiophene) nanofibers with enhanced nanozyme activity for highly sensitive colorimetric detection.

In this work, we have prepared CeO2/Co3O4 composite nanofibers via an electrospinning technique followed by a calcination process. Then core-shell structured CeO2/Co3O4/poly(3,4-ethylenedioxythiophene) (PEDOT) composite nanofibers were fabricated through a redox reaction between the 3,4-ethylenedioxythiophene (EDOT) monomer and Co3O4 on the surface of CeO2/Co3O4 composite nanofibers. The morphology and composition of the two composite nanofibers were confirmed by field-emission scanning electron microscopy, transmission electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and x-ray photoelectron spectra measurements. Due to the synergistic effect between CeO2 and Co3O4, the catalytic activity was enhanced compared to that of independent oxide nanofibers. After the growth of PEDOT, the catalytic activity process was further improved, having achieved a secondary synergistic effect. Application of the two prepared composite nanofibers as peroxidase-like catalysts for the colorimetric detection of H2O2 was investigated. It is anticipated that this work can inspire researchers to develop various novel functional nanocomposites for applications in biosensing and environmental monitoring.

Counterclockwise maxillomandibular advancement: a choice for Chinese patients with severe obstructive sleep apnea.

PURPOSE: Maxillomandibular advancement (MMA) is an effective alternative for treating severe obstructive sleep apnea (OSA). However, the promotion of MMA in China is limited by many Chinese patients having a convex facial profile. To achieve maximal upper airway enlargement without an esthetic disaster, we added counterclockwise rotation of the maxillomandibular complex (MMC) in the routine MMA. In this paper, we have evaluated the objective and subjective outcomes of this technology. METHODS: In total, 33 severe OSA patients who accepted counterclockwise maxillomandibular advancement (CMMA) were investigated in this study. Genioplasty, uvulopalatopharyngoplasty (UPPP), and turbinate reduction were also performed on selected patients. Polysomnography (PSG) and Epworth sleepiness scale (ESS) were chosen to evaluate the effectiveness of this technology in treating OSA. Patients' facial appearances were evaluated by cephalometric analysis and 5-point Likert scales. RESULTS: After CMMA, the apnea-hypopnea index (AHI) decreased from 59.3 ± 14.6 to 10.2 ± 6.7 (P < 0.001), minimum SpO2 (pulse oxygen saturation, %) increased from 74.0 ± 11.7 to 88.8 ± 4.4 (P < 0.001), and ESS decreased from 12.5 ± 2.3 to 7.3 ± 2.1. It is encouraging that soft-tissue cephalometric measurements such as facial convexity angle, nasolabial angle, and labiomental fold were not worsening after surgery. The Likert scales revealed that 28 patients (85%) were satisfied or very satisfied with their facial changes. In addition, no patient complained about dental function after surgery. CONCLUSIONS: These findings indicate that CMMA is an effective way to achieve a balance between airway enlargement and facial appearance for Chinese patients with severe OSA.

Combined Counterclockwise Maxillomandibular Advancement and Uvulopalatopharyngoplasty Surgeries for Severe Obstructive Sleep Apnea.

As the most effective surgical technique maxillomandibular advancement (MMA) has been used to treat severe obstructive sleep apnea (OSA) in adults, particularly for those who are intolerant of continuous positive airway pressure. Yet for large-scale advancement, it is faced with esthetic problems with marked skeletal protrusion especially for people with convex facial profile. In this study, the authors performed counterclockwise MMA combined with quantified uvulopalatopharyngoplasty (UPPP) surgeries on Chinese adult patients with severe OSA, in order to initially explore the efficacy of these procedures on Chinese populations and provide evidence for esthetic advantages. As the primary procedure counterclockwise MMA was applied on 10 patients, achieving a forward distance of the mandible and the maxilla for 10.6 and 6.7 mm, respectively, and the occlusion plane rotated counterclockwise of 6.2°. After a follow-up of beyond 12 months, polysomnography results showed the apnea-hypopnea index (AHI) significantly decreased from 64.3 to 11.0 per hour, achieving surgical success of 90%. Upper airway measurements demonstrated that the retropalatal and retrolingual spaces got enlarged greatly, resulting in significant AHI reduction and oxygen saturation elevation. More importantly, cephalometric analysis revealed that SNA and SNB were enlarged but in well control without visual abnormalities. Follow-up results showed large-scale advancement of the maxilla and mandible were stable in treating severe OSA. Quantified UPPP surgeries guaranteed no functional insufficiency in pronouncing and swallowing and played auxiliary role in enlarging the upper airway. Thus, procedures of counterclockwise MMA combined with quantified UPPP surgeries might find more application especially in patients with severe OSA with convex facial profile in future.

Individualized therapy for treating obstructive sleep apnea in pediatric Crouzon syndrome patients.

PURPOSE: Pediatric patients with Crouzon syndrome have great possibilities of suffering from obstructive sleep apnea (OSA), which is mainly due to midfacial hypoplasia and facial deformities. For most patients, a multidisciplinary and sequential treatment plan is necessary to make for Crouzon syndrome often has different phenotypes of different severity in OSA and facial deformities. Typical patients were selected in this paper to illustrate the necessity of individualized therapy for treating OSA. METHODS: In this paper, we have introduced four Crouzon syndrome children of different severity in suffering from OSA and maxillofacial deformities. Detailed information was given including clinical manifestations, radiological findings, and polysomnography detections. Based on the above findings, different but effective treatment options for these children's OSA problems were adopted, either by surgeries including distraction osteogenesis and craniomaxillofacial surgeries with or without tonsillectomy or by noninvasive continuous positive airway pressure (CPAP) therapy. RESULTS: Follow-up studies for more than 1 year showed problems of OSA and nocturnal hypoxia of those four patients were all alleviated greatly, as well as maxillofacial deformities. Combined with pre-operative and post-operative orthodontics, one patient also got optimal results in better facial profile and dental occlusion. CONCLUSION: Thus, based on adequate clinical evaluations and patients' conditions including age, disease severity, and esthetic considerations, individualized therapy should be made and performed carefully to obtain optimized results in treating OSA for pediatric Crouzon syndrome patients.

Oral appliance effectively reverses Muller's maneuver-induced upper airway collapsibility in obstructive sleep apnea and hypopnea syndrome.

OBJECTIVES: To verify the effects of oral appliance (OA) on upper airway morphology under intraluminal pressure, identify specific sites of upper airway collapsibility that can be reversed by OAs, and determine the relationship between OA efficacy and dynamic upper airway changes using computed tomography (CT) with Muller's maneuver. MATERIALS AND METHODS: Nineteen adult Chinese patients with symptomatic mild-to-moderate sleep apnea were recruited from our sleep center. Each patient was fitted with a two-piece OA. Dynamic changes in the retropalatal and retroglossal airway were evaluated using CT at end-expiration and during Muller's maneuver, both with and without an OA. RESULTS: Upper airway changes in the end-expiration phase before OA placement did not significantly differ from those after OA placement. However, under intraluminal pressure induced by Muller's maneuver, OA effectively expanded the upper airway at multiple levels. In addition, OA counteracted negative intraluminal pressure more effectively in the retropalatal region than in the retroglossal region, with 95.65, 68.75, 72.41, and 78.38 % improvements in the collapsibility index of the anteroposterior dimension, transverse dimension, minimum cross-sectional area, and volume of the retropalatal region, respectively. Both nonresponders and responders to OA treatment were sensitive to the intraluminal pressure induced by Muller's maneuver. However, the collapsibility of the retropalatal airway improved significantly only in the responders, not in the nonresponders. CONCLUSIONS: OA effectively treats OSAHS by improving upper airway collapsibility.

A novel electrospun nerve conduit enhanced by carbon nanotubes for peripheral nerve regeneration.

For artificial nerve conduits, great improvements have been achieved in mimicking the structures and components of autologous nerves. However, there are still some problems in conduit construction, especially in terms of mechanical properties, biomimetic surface tomography, electrical conductivity and sustained release of neurotrophic factors or cells. In this study, we designed and fabricated a novel electrospun nerve conduit enhanced by multi-walled carbon nanotubes (MWNTs) on the basis of a collagen/poly(ε-caprolactone) (collagen/PCL) fibrous scaffold. Our aim was to provide further knowledge about the mechanical effects and efficacy of MWNTs on nerve conduits as well as the biocompatibility and toxicology of MWNTs when applied in vivo.The results showed that as one component, carboxyl MWNTs could greatly alter the composite scaffold's hydrophilicity, mechanical properties and degradability. The electrospun fibers enhanced by MWNTs could support Schwann cell adhesion and elongation as a substrate in vitro. In vivo animal studies demonstrated that the MWNT-enhanced collagen/PCL conduit could effectively promote nerve regeneration of sciatic nerve defect in rats and prevent muscle atrophy without invoking body rejection or serious chronic inflammation. All of these results showed that this MWNT-enhanced scaffold possesses good biocompatibility and MWNTs might be excellent candidates as engineered nanocarriers for further neurotrophic factor delivery research.

Application of a novel intraorally customized transport distraction device in the reconstruction of segmental mandibular defect.

PURPOSE: The purpose of this study was to evaluate the clinical result of segmental mandible reconstruction by using a novel intraorally customized trifocal curvilinear distractor. METHODS: A customized curvilinear distractor with self-locking system and bidirection transport assembly was designed on the basis of the mandibular contour of a patient diagnosed with ameloblastoma. Two transport disks, each containing the first molar, were designed for trifocal distraction osteogenesis after partial mandibulectomy intraorally. The latency period is 7 days and distraction rhythm is 1 mm/d. After 6 months of consolidation, the second operation was performed to remove the device. RESULTS: A new bone bridged the mandibular defects through transport distraction successfully. Partial bony nonunion between the transport disks was noted when removing the distractor; rigid internal fixation using a titanium plate and bone graft was carried out to ensure the continuity. Bilateral sagittal split ramus osteotomy was performed to advance the mandible when anterior-posterior jaw bone discrepancy occurred before final denture restoration. CONCLUSIONS: Customized trifocal curvilinear transport distraction osteogenesis can successfully reconstruct segmental mandible defect intraorally, but special consideration should be paid on the dock site bone healing and overcorrection of curvilinear reconstruction in the future.

The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats.

The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment. However, the sensitivity of existing detection techniques is not sufficient, and the criteria for evaluating optimal force have not been yet established. Here, by employing 3D finite element analysis methodology, we found that the apical distal region (A-D region) of mesial roots is particularly sensitive to orthodontic force in rats. Tartrate-resistant acidic phosphatase (TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams (g), leading to alveolar bone resorption and tooth movement. When the force reached 80 g, TRAP-positive osteoclasts started appearing on the root surface in the A-D region. Additionally, micro-computed tomography revealed a significant root resorption at 80 g. Notably, the A-D region was identified as a major contributor to whole root resorption. It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement, inclination, and hyalinization. These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model. Collectively, our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients' orthodontic treatment.

Tuning the fluorescent response of a novel electroactive polymer with multiple stimuli.

A novel polymer featuring oligoaniline pendants that exhibits reversible electroactivity and good electrochromic properties with high contrast value, acceptable switching times, and excellent coloration efficiency is presented. This polymer can undergo reversible changes in fluorescence in response to reductive and oxidative chemical stimulus, pH, and electrical potential. The fluorescence switching operation shows reasonable reversibility and reproducibility when subjected to multiple stimuli. In this elegant fluorescence switching system, the oligoaniline pendants are used as fluorophore and regulatory units simultaneously.

Bone-anchored maxillary expansion and bilateral interoral mandibular distraction osteogenesis in adult with severe obstructive sleep apnea syndrome.

Severe obstructive sleep apnea syndrome (OSAS) threatens patients' lives. To solve ventilation problem, snoring, and avoid another orthognathic surgery for mandibular advancement, bone-anchored rapid maxillary expansion and bilateral interoral mandibular distraction osteogenesis were tried on a 20-year-old Chinese male patient with severe skeletal class II malocclusion and OSAS.The patient had polysomnography (apnea-hypopnea index 54.2), body mass index measurement (19.7 kg/m), and cephalometry before the treatment. Bone-anchored rapid maxillary expansion was performed for the correction of maxillary transverse and minor sagittal deficiency and the improvement of nasal airflow by decreasing nasal resistance. Bilateral interoral mandibular distraction osteogenesis was operated to lengthen the small, retruded mandible by 15 mm. Orthodontic treatment after the maxillary expansion and mandibular distraction osteogenesis can help obtain stable occlusion.The Epworth Sleepiness Scale, a questionnaire for temporomandibular joint, cephalometric analysis, polysomnography, acoustic rhinometry, and multislice spiral computed tomography were performed to evaluate changes from the treatment. All the results showed that the patient had a significantly alleviated OSAS. In addition, an acceptable occlusion was also obtained.

Evaluation of treatment with unilateral mandibular sagittal split ramus osteotomy and maxillary osteotomy in patients with condylar osteochondroma and mandibular asymmetry: A retrospective case series.

The aim of the study was to describe an approach where condylar resection with condylar neck preservation was combined with Le Fort I osteotomy and unilateral mandibular sagittal split ramus osteotomy (SSRO). Patients with a unilateral condylar osteochondroma combined with dentofacial deformity and facial asymmetry who underwent surgery between January 2020 and December 2020 were enrolled. The operation included condylar resection, Le Fort I osteotomy and contralateral mandibular sagittal split ramus osteotomy (SSRO). Simplant Pro 11.04 software was used to reconstruct and measure the preoperative and postoperative craniomaxillofacial CT images. The deviation and rotation of the mandible, change in the occlusal plane, position of the "new condyle" and facial symmetry were compared and evaluated during follow-up. Three patients were included in the present study. The patients were followed up for 9.6 months on average (range, 8-12). Immediate postoperative CT images showed that the mandible deviation and rotation and occlusion plane canting decreased significantly postoperatively; facial symmetry was improved but still compromised. During the follow-up, the mandible gradually rotated to the affected side, the position of the "new condyle" moved further inside toward the fossa, and both the mandible rotation and facial symmetry were more significantly improved. Within the limitations of the study it seems that for some patients a combination of condylectomy with condylar neck preservation and unilateral mandibular SSRO can be effective in achieving facial symmetry.

Electrospun Nanofibers: Current Progress and Applications in Food Systems.

Electrospinning has the advantages of simple manufacturing equipment, a low spinning cost, wide range of spinnable materials, and a controllable mild process, which can continuously fabricate submicron or nanoscale ultrafine polymer fibers without high temperature or high pressure. The obtained nanofibrous films may have a large specific surface area, unique pore structure, and easy-to-modify surface characteristics. This review briefly introduces the types and fiber structures of electrospinning and summarizes the applications of electrospinning for food production (e.g., delivery systems for functional food, filtration of beverages), food packaging (e.g., intelligent packaging, antibacterial packaging, antioxidant packaging), and food analysis (e.g., pathogen detection, antibiotic detection, pesticide residue detection, food compositions analysis), focusing on the advantages of electrospinning applications in food systems. Furthermore, the limitations and future research directions of the technique are discussed.

Extraction of benzoylurea insecticides from tea leaves based on thermoplastic polyethyleneimine embedded magnetic nanoparticle carbon materials.

A novel mosaic structured core-shell composite, Silica@C/Ni (Sil@C/Ni), has been prepared by embedding Ni nanoparticles on the surface of silica microspheres via coordination and carbonization reduction, and was used as magnetic solid-phase extraction sorbents in combination with high performance liquid chromatography (HPLC) for the extraction and determination of four benzoylurea insecticides (BUs) in tea leaves. Based on the fact that hydrogen bonding and hydrophobic interactions exist between the material and BUs, allowing BUs on the surface of the material can achieve rapid mass transfer and improved sorption performance, satisfactory extraction recoveries have been achieved in practical sample applications. Under the optimized experimental conditions, the linear ranges were 0.5-200 µg L-1 for diflubenzuron and triflumuron, 1.0-200 µg L-1 for teflubenzuron and 0.8-200 µg L-1 for flufenoxuron with the correlation coefficients R2 ≥ 0.9991. The method has limits of detection and limits of quantification of 0.2-0.4 µg L-1 and 0.5-1.0 µg L-1, respectively. The intra-day and inter-day relative standard deviations were less than 5%. The actual sample recoveries were 76.63-95.26%. In addition, Sil@C/Ni was used repeatedly for 15 times and still showed a relatively satisfactory recovery of the four BUs. Therefore, Sil@C/Ni has a high stability and can be used as an ideal magnetic solid phase extraction sorbent for the trace enrichment of BUs in tea-leaf samples.