A low-swelling hydrogel as a multirole sealant for efficient dural defect sealing and prevention of postoperative adhesion.

Dural defects and subsequent complications, including cerebrospinal fluid (CSF) leakage, are common in both spine surgery and neurosurgery, and existing clinical treatments are still unsatisfactory. In this study, a tissue-adhesive and low-swelling hydrogel sealant comprising gelatin and o-phthalaldehyde (OPA)-terminated 4-armed poly(ethylene glycol) (4aPEG-OPA) is developed via the OPA/amine condensation reaction. The hydrogel shows an adhesive strength of 79.9 ± 12.0 kPa on porcine casing and a burst pressure of 208.0 ± 38.0 cmH2O. The hydrogel exhibits a low swelling ratio at physiological conditions, avoiding nerve compression in the limited spinal and intracranial spaces. In rat and rabbit models of lumbar and cerebral dural defects, the 4aPEG-OPA/gelatin hydrogel achieves excellent performance in dural defect sealing and preventing CSF leakage. Moreover, local inflammation, epidural fibrosis and postoperative adhesion in the defect areas are markedly reduced. Thus, these findings establish the strong potential of the hydrogel sealant for the effective watertight closure of dural defects.

Intradural extramedullary spinal choristoma: A case report.

RATIONALE: A choristoma is a rare and benign neoplasm characterized by the presence of normal tissue in an anomalous anatomical location. In contrast, choristoma tend to occur in other body regions rather than within the spinal canal. Before our findings, only 4 cases of intraspinal choristoma had been recorded. Because its composition is complex and very rare, routine examinations, such as magnetic resonance imaging, are difficult to diagnose, and the possibility of its occurrence is often missed in clinical diagnosis. If there is no specificity in its components, such as in this case, even pathological examinations can only confirm the diagnosis as choristoma after eliminating other possibilities. Therefore, in clinical practice, when encountering patients with intraspinal tumors, it is essential to consider the possibility of choristoma. In this case, the choristoma lack of specific constituent composition sets it apart from previously reported intraspinal choristoma, significantly raising the diagnostic challenge, which offers valuable insights for clinical diagnosis. PATIENT CONCERNS: A female patient aged 48 years was admitted to our medical center due to experiencing persistent lower back pain accompanied by radiating pain in both legs for 5 months. Based on the findings from the neurological physical examination and magnetic resonance imaging, the patient was diagnosed with an intradural space-occupying lesion located at the level of the first lumbar vertebral body. We performed an enhanced magnetic resonance neurography examination to further determine the positional relationship between the occupation and nerves in preparation for surgery. Postoperative pathological biopsy showed that the mass was an intraspinal choristoma. DIAGNOSIS: Intradural extramedullary spinal choristoma. INTERVENTION: Occupied lesion is removed surgically. OUTCOMES: After surgery, all symptoms were significantly relieved, and when the patient was discharged, all symptoms disappeared completely. There was no sign of recurrence after 1 year of follow-up. LESSONS: Intraspinal choristomas are not specific and need to be diagnosed by pathologic examination. Early detection of and intervention for intraspinal tumors can mitigate nerve dysfunction.

Injectable, self-healing hydrogel adhesives with firm tissue adhesion and on-demand biodegradation for sutureless wound closure.

Tissue adhesives have garnered extensive interest as alternatives and supplements to sutures, whereas major challenges still remain, including weak tissue adhesion, inadequate biocompatibility, and uncontrolled biodegradation. Here, injectable and biocompatible hydrogel adhesives are developed via catalyst-free o-phthalaldehyde/amine (hydrazide) cross-linking reaction. The hydrogels demonstrate rapid and firm adhesion to various tissues, and an o-phthalaldehyde-mediated tissue adhesion mechanism is established. The hydrogel adhesives show controlled degradation profiles of 6 to 22 weeks in vivo through the incorporation of disulfide bonds into hydrogel network. In liver and blood vessel injury, the hydrogels effectively seal the incisions and rapidly stop bleeding. In rat and rabbit models of full-thickness skin incision, the hydrogel adhesives quickly close the incisions and accelerate wound healing, which exhibit efficacies superior to those of commercially available fibrin glue and cyanoacrylate glue. Thus, the hydrogel adhesives show great potential for sutureless wound closure, hemostasis sealing, and prevention of leakage in surgical applications.

Injectable antibacterial tissue-adhesive hydrogel based on biocompatible o-phthalaldehyde/amine crosslinking for efficient treatment of infected wounds.

Injectable antibacterial hydrogels have attracted considerable attention in wound management. However, the development of injectable hydrogels with excellent antibacterial activity, good biocompatibility, and strong tissue adhesion remains a challenge. In this study, an antibacterial tissue-adhesive hydrogel was developed based on a catalyst-free o-phthalaldehyde (OPA)/amine reaction by simply mixing OPA-terminated four-arm poly(ethylene glycol) (4aPEG-OPA) and ε-poly-l-lysine (ε-PLL) solutions. The hydrogel showed tunable gelation time, storage moduli, and degradation rate depending on the polymer concentration and 4aPEG-OPA/ε-PLL mass ratio. The hydrogel exhibited nearly 100% bacterial inhibition rates in-vitro against Gram-negative E. coli and Gram-positive S. aureus, while maintaining good biocompatibility. The hydrogel matched well in shape and tightly adhered to the tissue after in-situ formation at the wound sites. Following the treatment of rat models of full-thickness skin incisions and round wounds, the hydrogel effectively closed the wounds and promoted wound healing. Moreover, after administering to S. aureus infected full-thickness skin wounds, the hydrogel exhibited remarkable efficacy in inhibiting wound infection with a bacterial inhibition rate over 99.94%, achieving a significantly accelerated wound healing compared with the commercially available Prontosan® gel. Therefore, the hydrogel exhibits great potential as a wound dressing for infection prevention and promotion of healing.

Peptide/glycyrrhizic acid supramolecular polymer: An emerging medical adhesive for dural sealing and repairing.

Medical adhesives have emerged as potential materials for sealing, hemostasis and wound repairing in modern clinical surgery. However, most of existing medical adhesives are still far away from the clinical requirements for simultaneously meeting desirable tissue adhesion, safety, biodegradability, anti-swelling property, and convenient operability. Here, we present an entirely new kind of peptide-based underwater adhesives, which are constructed via cross-linked supramolecular copolymerization between cationic short peptides and glycyrrhizic acid (GA) in an aqueous solution. We revealed the unique molecular mechanism of the peptide/GA supramolecular polymers and underlined the importance of arginine residues in the enhancement of the bulk cohesion of the peptide/GA adhesive. We thus concluded a design guideline that the peptide sequence has to be encoded with multiple arginine termini and hydrophobic residues. The resulting adhesives exhibited effective tissue adhesion, robust cohesion, low cell cytotoxicity, acceptable hemocompatibility, inappreciable inflammation response, appropriate biodegradability, and excellent anti-swelling property. More attractively, the dried peptide/GA powder was able to rapidly self-gel into adhesives by absorbing water, suggesting conveniently clinical operability. Animal experiments showed that the peptide/GA supramolecular polymers could be utilized as reliable medical adhesives for dural sealing and repairing.

Late presentation of dural tears: Two case reports and review of literature.

BACKGROUND: The late presentation of dural tears (LPDT) has a low incidence rate and hidden symptoms and is easily ignored in clinical practice. If the disease is not treated in time, a series of complications may occur, including low intracranial pressure headache, infection, pseudodural cyst formation, and sinus formation. Here, we describe two cases of LPDT. CASE SUMMARY: Two patients had sudden fever 1 wk after lumbar surgery. Physical examination showed obvious tenderness in the operation area. The patients were confirmed as having LPDT by lumbar magnetic resonance imaging and surgical exploration. One case was caused by continuous negative pressure suction and malnutrition, and the other was caused by decreased dural ductility and low postoperative nutritional status. The first symptom of both patients was fever, with occasional headache. Both patients underwent secondary surgery to treat the LPDT. Dural defects were observed and dural sealants were used to seal the dural defects, then drainage tubes were retained for drainage. After the operation, the patients were treated with antibiotics and the patients' surgical incisions healed well, without fever or incision tenderness. Both recovered and were discharged 1 wk after the operation. CONCLUSION: LPDT is a rare complication of spinal surgery or neurosurgery that has hidden symptoms and can easily be overlooked. Since it may cause a series of complications, LPDT needs to be actively addressed in clinical practice.

Clinical management of dural defects: A review.

Dural defects are common in spinal and cranial neurosurgery. A series of complications, such as cerebrospinal fluid leakage, occur after rupture of the dura. Therefore, treatment strategies are necessary to reduce or avoid complications. This review comprehensively summarizes the common causes, risk factors, clinical complications, and repair methods of dural defects. The latest research progress on dural repair methods and materials is summarized, including direct sutures, grafts, biomaterials, non-biomaterial materials, and composites formed by different materials. The characteristics and efficacy of these dural substitutes are reviewed, and these materials and methods are systematically evaluated. Finally, the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed.

Plant Protein-Peptide Supramolecular Polymers with Reliable Tissue Adhesion for Surgical Sealing.

The fusion of protein science and peptide science opens up new frontiers in creating innovative biomaterials. Herein, a new kind of adhesive soft materials based on a natural occurring plant protein and short peptides via a simple co-assembly route are explored. The hydrophobic zein is supercharged by sodium dodecyl sulfate to form a stable protein colloid, which is intended to interact with charge-complementary short peptides via multivalent ionic and hydrogen bonds, forming adhesive materials at macroscopic level. The adhesion performance of the resulting soft materials can be fine-manipulated by customizing the peptide sequences. The adhesive materials can resist over 78 cmH2 O of bursting pressure, which is high enough to meet the sealing requirements of dural defect. Dural sealing and repairing capability of the protein-peptide biomaterials are further identified in rat and rabbit models. In vitro and in vivo assays demonstrate that the protein-peptide adhesive shows excellent anti-swelling property, low cell cytotoxicity, hemocompatibility, and inflammation response. In particular, the protein-peptide supramolecular biomaterials can in vivo dissociate and degrade within two weeks, which can well match with the time-window of the dural repairing. This work underscores the versatility and availability of the supramolecular toolbox in the easy-to-implement fabrication of protein-peptide biomaterials.

Injectable Polypeptide Hydrogel Depots Containing Dual Immune Checkpoint Inhibitors and Doxorubicin for Improved Tumor Immunotherapy and Post-Surgical Tumor Treatment.

In this work, we developed a strategy for local chemo-immunotherapy through simultaneous incorporation of dual immune checkpoint blockade (ICB) antibodies, anti-cytotoxic T-lymphocyte-associated protein 4 (aCTLA-4) and anti-programmed cell death protein 1 (aPD-1), and a chemotherapy drug, doxorubicin (Dox), into a thermo-gelling polypeptide hydrogel. The hydrogel encapsulating Dox or IgG model antibody showed sustained release profiles for more than 12 days in vitro, and the drug release and hydrogel degradation were accelerated in the presence of enzymes. In comparison to free drug solutions or hydrogels containing Dox or antibodies only, the Dox/aCTLA-4/aPD-1 co-loaded hydrogel achieved improved tumor suppression efficiency, strengthened antitumor immune response, and prolonged animal survival time after peritumoral injection into mice bearing B16F10 melanoma. Additionally, after injection of Dox/aCTLA-4/aPD-1 co-loaded hydrogel into the surgical site following tumor resection, a significantly enhanced inhibition on tumor reoccurrence was demonstrated. Thus, the polypeptide hydrogel-based chemo-immunotherapy strategy has potential in anti-tumor therapy and the prevention of tumor reoccurrence.

Thermosensitive vancomycin@PLGA-PEG-PLGA/HA hydrogel as an all-in-one treatment for osteomyelitis.

Osteomyelitis is a difficult-to-treat infectious disease. Treatment, which includes controlling the infection and removing necrotic tissues, is challenging. Considering the side effects and drug resistance of systemic antibiotics, local drug delivery systems are being explored. Antibiotic-loaded bone cement is the main treatment strategy; however, it has several disadvantages. Thus, based on its thermosensitive gelation properties, poly(D, L-lactide-co-glycolide)-poly(ethylene glycol)-poly(D, L-lactide-co-glycolide) (PLGA-PEG-PLGA) copolymer was used as a sustained-release drug carrier by calibrating its synthesis parameters. We prepared and characterized vancomycin@PLGA-PEG-PLGA/hydroxyapatite (HA) thermosensitive hydrogel with an LA/GA ratio of 15:1. The rheological characteristics, sol-gel phase-transition properties, and critical micelle concentration value of the PLGA-PEG-PLGA/HA complex confirmed that it undergoes a temperature-sensitive sol-gel phase transition. Furthermore, the HA in the composite increased the storage modulus of the system. FT-IR, XRD, and TEM findings showed that HA could be dispersed uniformly in the PLGA-PEG-PLGA polymer. Moreover, HA neutralized acidity during polymer degradation, improving in vitro cytocompatibility. In vitro and in vivo antibacterial experiments showed that the composite sustained-release system exhibited good bone repair characteristics owing to its efficacy in infection treatment. Therefore, vancomycin@PLGA-PEG-PLGA/HA allows sustained release of antibiotics and promotes bone tissue repair, showing potential for wide clinical applicability.

Mucoadhesive, Antibacterial, and Reductive Nanogels as a Mucolytic Agent for Efficient Nebulized Therapy to Combat Allergic Asthma.

Asthma is an intractable disease involving the infiltration of inflammatory cells and mucus plugging. Despite small molecular mucolytics having the ability to break the disulfide bonds of mucins, offering a potential way to overcome the airflow obstruction and airway infection, these mucolytics have limited therapeutic effects in vivo. Therefore, in this work, arginine-grafted chitosan (CS-Arg) is ionically cross-linked with tris(2-carboxyethyl)phosphine (TCEP) to obtain nanogels as a mucolytic agent. The positively charged nanogels effectively inhibit the formation of large aggregates of mucin in vitro, probably thanks to the formation of an ionic interaction between CS-Arg and mucin, as well as the breakage of disulfide bonds in mucin by the reductive TCEP. Moreover, the nanogels show good cytocompatibility at concentrations up to 5 mg mL-1, exhibiting effective inhibitory effects against the proliferation of both Staphylococcus aureus and Escherichia coli at 5 mg mL-1. After the administration of the nanogels by nebulization into a Balb/c mouse model with allergic asthma, they can efficiently reduce the mucus obstruction in bronchioles and alveoli and relieve airway inflammation. Therefore, these CS-Arg/TCEP nanogels potentially represent a promising mucolytic agent for the efficient treatment of allergic asthma and other muco-obstructive diseases.

A comparison of long-term efficacy of K-rod-assisted non-fusion operation and posterior lumbar interbody fusion for single-segmental lumbar disc herniation.

K-rod-assisted non-fusion surgery for the treatment of lumbar disc herniation has been proven to have short-term clinical efficacy. Meanwhile, its long-term effects have not been examined. To observed the long-term clinical efficacy of K-rod-assisted non-fusion operation, this study retrospectively analyzed 22 patients with lumbar disc (L4/5) herniation who underwent K-rod-assisted non-fusion operation (n = 13) or PLIF (n = 9). They were followed-up for more than 5 years. The operation times and blood loss were significantly reduced in the K-rod group compared to the PLIF group. At the last follow-up, the clinical outcomes of the K-rod group were improved compared to those of the PLIF group as observed by the VAS score, JOABPEQ, and ODI. Imaging outcomes at the last follow-up indicated that the loss of height in the L3/4 and L5/S1 intervertebral space, the ROM of L3/4 and L5/S1, and the incidence of adjacent segment degeneration in the PLIF group were significantly higher than those in the K-rod group. According to Pfirrmann grading, Modic changes, and UCLA grading, the incidence of adjacent segment degeneration was 55.6% in the PLIF group and 15.4% in the K-rod group. Changes in spino-pelvic parameters between the two groups were as follows: pelvic index remained unchanged, pelvic tilt angle increased, and lumbar lordosis and sacral slope decreased. Therefore, compared to PLIF, single-segment lumbar disc herniation using K-rod-assisted non-fusion surgery resulted in better long-term clinical efficacy. Our results demonstrate that this procedure can delay adjacent segment degeneration after lumbar surgery.

Osteoporotic Vertebral Fracture Misdiagnosed as Metastatic Vertebral Fracture.

The purpose of this study was to report a patient with osteoporotic vertebral compression fracture (OVCF) which was misdiagnosed as metastatic vertebral compression fracture (MVCF). A 64-year male was admitted to our clinic for complaints of numbness, pain, and activity limitation in bilateral lower extremities. One year ago, he had a medical history of lung adenocarcinoma and bone metastasis. A month ago, he developed back pain and lower-limb paralysis. X-ray, computer tomography (CT), and magnetic resonance imaging (MRI) showed thoracic 11 (T11) vertebral compression fracture. Furthermore, emission computed tomography (ECT) indicated MVCF preoperatively. However, the histopathology findings suggested OVCF postoperatively. Consequently, the patient was discharged without chemoradiotherapy. During the 14-months follow-up period, no relapsed spinal neoplasm or recurrence of vertebral fracture was observed. In conclusion, OVCF in patients with a history of lung cancer is easily misdiagnosed as MVCF. It is important to differentiate OVCF from MVCF by clinical symptoms, laboratory examination, and imaging features before operation. Histological findings are the gold standard for accurate diagnosis. Key Words: Osteoporosis, Vertebral fracture, Metastasis.

Spinal dural arteriovenous fistula 8 years after lumbar discectomy surgery: A case report and review of literature.

BACKGROUND: Spinal dural arteriovenous fistula (SDAVF) is an extremely rare vascular malformation of the central nervous system that is often confused with degenerative spinal disorders due to similar early symptoms and clinical features. Here, we report a case of SDAVF recurrence 8 years after lumbar spine surgery and summarize relevant literature. CASE SUMMARY: A 54-year-old male was admitted to our hospital complaining of lower back pain, numbness in both lower extremities and intermittent claudication. Subsequent imaging identified lumbar spinal stenosis. Following surgical treatment, the patient's symptoms significantly resolved, and he was able to perform daily activities. However, similar symptoms appeared 8 years later, followed by confirmation of SDAVF diagnosis. The patient underwent neurosurgery 7 mo after symptom onset. The follow-up period lasted 14 mo, and the patient remains with marginal neurological symptoms. CONCLUSION: This case highlights the importance of prompt SDAVF diagnosis. Due to its nonspecific clinical presentation, the clinical experience of the surgeon and definitive imaging examination are indispensable. Additionally, timely neurosurgery is effective and may significantly improve patient outcomes.

Chitosan-Coated Titanium Dioxide-Embedded Paclitaxel Nanoparticles Enhance Anti-Tumor Efficacy Against Osteosarcoma.

OBJECTIVE: Titanium dioxide nanoparticles (TiO2) nanoparticles have been widely explored in the prevention of cancer risk. Due to the difficult solubility of TiO2 nanoparticles, it is essential to synthesize new surfactants to increase its bioavailability and anti-tumor activity and reduce its cytotoxicity. Furthermore, oxidative and inflammation are closely associated with the osteosarcoma risk. Chitosan has biocompatibility, antioxidant and anti-inflammatory properties. The effects of chitosan-coated TiO2-embedded paclitaxel nanoparticles on an osteosarcoma model were explored. METHODS: An osteosarcoma model was established and chitosan-coated TiO2-embedded paclitaxel nanoparticles were prepared using a freeze-drying strategy. The morphological characteristics of nanoparticles were observed using scanning electron microscopy (SEM). The physicochemical properties of nanoparticle were evaluated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The cytotoxicity was tested by using human osteoblast cells hFob1.19 and osteosarcoma cells 143B. Osteosarcoma mice were treated with PBS buffer, paclitaxel, TiO2-embedded paclitaxel and chitosan-coated TiO2-embedded paclitaxel nanoparticles. The biomarkers of oxidative-inflammatory status, anti-tumor activities and survival rates of the model were measured. RESULTS: XRD analysis showed that the peaks of chitosan/TiO2 (anatase) were consistent with those of crystalline TiO2 and broad phase of chitosan. The FTIR spectrum indicated the relevant functional groups in TiO2. Chitosan-coated TiO2-embedded paclitaxel nanoparticles had good biocompatibility and improve antioxidant and anti-inflammatory properties in the osteosarcoma model. Chitosan-coated TiO2-embedded paclitaxel nanoparticles was less toxic to the cells hFob1.19 and more toxic to the cells 143B than TiO2-embedded paclitaxel nanoparticles. Chitosan-coated TiO2-embedded paclitaxel nanoparticles showed significant antitumor activity and increased the survival rate of the osteosarcoma model (P < 0.05). CONCLUSIONS: Chitosan improved anti-tumor potential of TiO2-embedded paclitaxel nanoparticles in the prevention of osteosarcoma.

Spontaneous spinal epidural hematoma masquerading as atypical abdominal pain in a child: A case report.

INTRODUCTION: There have been few case reports of abdominal pain as a symptom of spontaneous intraspinal hemorrhage. We herein describe a case involving a girl with paraplegia caused by spontaneous epidural hemorrhage in the thoracic spinal canal, characterized by abdominal pain. PATIENT CONCERNS: An 8-year-old girl with sudden abdominal pain and back pain was misdiagnosed as having an abdominal disease until she had the symptom of paralysis. DIAGNOSES: The patient was diagnosed with spontaneous intraspinal hemorrhage masquerading as atypical abdominal pain. INTERVENTIONS: When the patient developed symptoms of lower extremity paralysis, thoracic magnetic resonance imaging was performed and epidural hemorrhage was found in the thoracic spinal canal. Surgical treatment was performed after the diagnosis was confirmed. OUTCOMES: The patient could almost walk normally after 3 months. One year after surgery, the Frankel grade of spinal cord function was grade D. We continued to follow-up this patient. CONCLUSION: The symptoms caused by intraspinal hemorrhage are mainly back pain with or without neurological dysfunction. However, sometimes atypical symptoms, such as abdominal and chest pain, can be identified in clinical settings. Emergency surgery is recommended as the treatment of choice for intraspinal hemorrhage with neurological dysfunction.

Computer navigation-assisted minimally invasive percutaneous screw placement for pelvic fractures.

Pelvic fractures are often caused by high-energy injuries and accompanied by hemodynamic instability. Traditional open surgery has a large amount of bleeding, which is not suitable for patients with acute pelvic fracture. Navigation-guided, percutaneous puncture-screw implantation has gradually become a preferred procedure due to its advantages, which include less trauma, faster recovery times, and less bleeding. However, due to the complexity of pelvic anatomy, doctors often encounter some problems when using navigation to treat pelvic fractures. This article reviews the indications, contraindications, surgical procedures, and related complications of this procedure for the treatment of sacral fractures, sacroiliac joint injuries, pelvic ring injuries, and acetabular fractures. We also analyze the causes of inaccurate screw placement. Percutaneous screw placement under navigational guidance has the advantages of high accuracy, low incidence of complications and small soft-tissue damage, minimal blood loss, short hospital stays, and quick recovery. There is no difference in the incidence of complications between surgeries performed by new doctors and experienced ones. However, computer navigation technology requires extensive training, and attention should be given to avoid complications such as screw misplacement, intestinal injury, and serious blood vessel and nerve injuries caused by navigational drift.

[Ecological basis of epiphytic Dendrobium officinale growth on cliff].

In order to make Dendrobium officinale return to the nature, the temperature and humidity in whole days of the built rock model with different slopes and aspects in the natural distribution of wild D. officinale in Tianmu Mountain were recorded by MH-WS01 automatic recorder. The results showed that the slope has a significant impact on the extreme temperature on the surface of the rocks. In summer, the extreme temperature on the surface of horizontal or soft rock can reach to 69.4 ℃, while the temperatures were lower than 50 ℃ on the vertical rock. In winter, the temperatures on the surface of vertical rock were higher and the low temperature duration was shorter than those on the horizontal or soft rock. Also, the humidity of the rocks was significantly influenced by the slope. The monthly average humidity on the surface of vertical rock was above 80%RH. Furthermore, the aspect had a significant impact on the temperature and humidity on the surface of the rocks, but had no significant effect on the daily mean temperature and extreme temperature on the surface of vertical rock. Therefore, the slope affects the survival of D. officinale by affecting the extreme temperature of rocks and affects the growth of D. officinale by affecting the humidity. The choice of slope is the key to the success of cliff epiphytic cultivation for D. officinale.

Removal dynamics of nitric oxide (NO) pollutant gas by pulse-discharged plasma technique.

Nonthermal plasma technique has drawn extensive attentions for removal of air pollutants such as NO x and SO2. The NO removal mechanism in pulse discharged plasma is discussed in this paper. Emission spectra diagnosis indicates that the higher the discharge voltage is, the more the NO are removed and transformed into O, N, N2, NO2, and so forth. Plasma electron temperature T(e) is ranged from 6400 K at 2.4 kV discharge voltage to 9500 K at 4.8 kV. After establishing a zero-dimensional chemical reaction kinetic model, the major reaction paths are clarified as the electron collision dissociation of NO into N and O during discharge and followed by single substitution of N on NO to form N2 during and after discharge, compared with the small fraction of NO2 formed by oxidizing NO. The reaction directions can be adjusted by N2 additive, and the optimal N2/NO mixing ratio is 2 : 1. Such a ratio not only compensates the disadvantage of electron competitive consumption by the mixed N2, but also heightens the total NO removal extent through accelerating the NO oxidization process.