1.Clinical Characteristics and Prognostic Analysis of Extracranial Malignant Rhabdoid Tumor in Children
Shihan ZHANG ; Wen ZHAO ; Mei JIN ; Hongjun FAN ; Xisi WANG ; Libing FU ; Tong YU ; Yan SU
JOURNAL OF RARE DISEASES 2026;5(1):34-42
To investigate the clinical characteristics and prognosis of extracranial malignant rhabdoid tumor (eMRT) in children, and to provide a reference for the clinical treatment of this disease. A retrospective analysis was performed on the clinical data of children with newly diagnosed eMRT who were admitted and treated in the Department of Pediatric Oncology, Beijing Children's Hospital Affiliated to Capital Medical University, from March 2009 to December 2024. The clinical characteristics were summarized, and survival analysis and prognostic risk factor analysis were conducted. A total of 43 children with eMRT were included in this study, the median age at diagnosis of all patients was 20 months (range: 2-138 months). Among them, 24 cases were malignant renal rhabdoid tumors and 19 cases were extracranial, extrarenal rhabdoid tumors. Of the 43 children, 23 cases (53.5%) were complicated with distant metastasis. Twenty-nine (67.4%) underwent primary tumor resection. Among the children, 24 (55.8%) underwent gross total resection (GTR), 5 (11.6%) partial resection, and 14 (32.6%) biopsy only. Their 3-year overall survival (OS) rates were 40.8%, 35.3%, and 33.3%, respectively ( Children with eMRT have an overall poor prognosis. A diagnostic age < 12 months is an independent risk factor for higher mortality in these children. Further large-scale, long-term follow-up studies are needed to explore the prognostic factors of this disease.
2.Guizhi Shaoyao Zhimutang and Active Components of Its Single Herbs in Treatment of Rheumatoid Arthritis: A Review
Jian LIU ; SHIPEIRU ; Shuang LI ; Jinzhao ZHAO ; Naijun CAO ; Mingxiu JIN ; Jing YU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):346-354
Rheumatoid arthritis (RA) is a common autoimmune disease characterised clinically by symmetrical joint pain, swelling, and stiffness. Long-term chronic synovial inflammation can lead to severe joint damage and even disability, thereby affecting quality of life for patients. Current clinical treatment of RA emphasises an integrated approach combining traditional Chinese and Western medicine, with traditional Chinese medicine offering certain advantages in reducing disease activity of RA, preventing relapses, and other aspects. Modern clinical evidence confirms that Guizhi Shaoyao Zhimutang (GSZT) is effective in improving symptoms such as immune metabolism, joint stiffness, and joint pain in RA patients. Pharmacological studies have revealed that GSZT primarily contains components such as cinnamaldehyde, total glucosides of paeony, total alkaloids of Aconiti Lateralis Radix Praeparata, glycyrrhetinic acid, zingiberone, isoimperatorin, ephedra polysaccharides, and cedrol. It improves RA symptoms via multiple mechanisms and targets, including enhancing immune responses, exerting anti-inflammatory and analgesic effects, regulating relevant signalling pathways, inhibiting cell apoptosis, and suppressing bone destruction. This paper reviewed the syndrome patterns and pharmacological basis of GSZT in the treatment of RA, as well as its clinical applications and related mechanisms, thereby providing a theoretical basis and reference for the further development and utilisation of GSZT in the treatment of RA.
3.Guizhi Shaoyao Zhimutang and Active Components of Its Single Herbs in Treatment of Rheumatoid Arthritis: A Review
Jian LIU ; SHIPEIRU ; Shuang LI ; Jinzhao ZHAO ; Naijun CAO ; Mingxiu JIN ; Jing YU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):346-354
Rheumatoid arthritis (RA) is a common autoimmune disease characterised clinically by symmetrical joint pain, swelling, and stiffness. Long-term chronic synovial inflammation can lead to severe joint damage and even disability, thereby affecting quality of life for patients. Current clinical treatment of RA emphasises an integrated approach combining traditional Chinese and Western medicine, with traditional Chinese medicine offering certain advantages in reducing disease activity of RA, preventing relapses, and other aspects. Modern clinical evidence confirms that Guizhi Shaoyao Zhimutang (GSZT) is effective in improving symptoms such as immune metabolism, joint stiffness, and joint pain in RA patients. Pharmacological studies have revealed that GSZT primarily contains components such as cinnamaldehyde, total glucosides of paeony, total alkaloids of Aconiti Lateralis Radix Praeparata, glycyrrhetinic acid, zingiberone, isoimperatorin, ephedra polysaccharides, and cedrol. It improves RA symptoms via multiple mechanisms and targets, including enhancing immune responses, exerting anti-inflammatory and analgesic effects, regulating relevant signalling pathways, inhibiting cell apoptosis, and suppressing bone destruction. This paper reviewed the syndrome patterns and pharmacological basis of GSZT in the treatment of RA, as well as its clinical applications and related mechanisms, thereby providing a theoretical basis and reference for the further development and utilisation of GSZT in the treatment of RA.
4.Engineered Bacteriophages for The Treatment of Multidrug-resistant Bacterial Infections
Yu-Ying CHEN ; Chun-Mei HUANG ; Jin-Zhi PAN ; De-Liang LIU ; Yang ZHOU ; Gui-Qin DAI ; Peng-Fei ZHAO ; Hong-Zhou LU ; Ming-Bin ZHENG
Progress in Biochemistry and Biophysics 2026;53(6):1581-1596
Multidrug-resistant (MDR) bacterial infections have emerged as a serious challenge of global public health crisis. The overuse and misuse of conventional antibiotics have dramatically accelerated the emergence, evolution and worldwide spread of drug-resistant bacterial strains, necessitating urgent exploration of novel antibacterial strategies. Bacteriophages serve as natural bacterial predators offering distinct advantages including high host specificity, autonomous self-replication capabilities and cost-effective large-scale production. However, wild-type phages present significant clinical limitations due to their narrow host ranges, susceptibility to rapid immune clearance and poor penetration of bacterial biofilms, which severely restrict their therapeutic applications. The convergence of synthetic biology, nanotechnology and advanced gene editing technologies has accelerated the development of engineered bacteriophage platforms, providing programmable, scalable and clinically translatable pathways to overcome these inherent biological constraints. Here, we systematically delineate four fundamental strategies for engineered bacteriophage development. Chemical modification utilizes reactive functional groups such as amino, carboxyl and thiol moieties on capsid proteins through esterification, amidation or click chemistry reactions to achieve precise drug conjugation and surface functionalization. In vivo editing encompasses ultraviolet or chemical mutagenesis for random mutation induction, homologous recombination for targeted genetic alterations, recombineering methodologies including electroporation-mediated bacteriophage recombination engineering, and CRISPR-Cas systems for precise genome editing to enable exact genetic reconstruction and host range reprogramming. In vitro synthesis leverages genome engineering platforms where intact phage genomes are transferred into yeast or host bacteria to facilitate highly efficient homologous recombination, enabling large DNA fragment assembly and cross-gene host range expansion without bacterial toxicity constraints. Directed evolution combines artificial selection through mutation library screening with rational design approaches involving chimeric receptor binding protein construction or site-specific mutagenesis, effectively balancing the discovery of unknown adaptive pathways with targeted host specificity modification. Moreover, we comprehensively discuss therapeutic applications across diverse clinical scenarios. Engineered bacteriophage effectively disrupt bacterial biofilms through sophisticated functionalized delivery platforms including nanozyme-conjugated phages, phage-liposome nanoconjugates and bio-responsive hydrogels, demonstrating significantly enhanced bactericidal efficiency compared to unmodified free phages. These bioengineered vectors attenuate bacterial virulence and resensitize pathogens to antibiotics by delivering CRISPR-Cas systems or base editors to disrupt critical virulence factors such as pili, capsule synthesis machineries and quorum sensing systems, or by inactivating antibiotic resistance determinants including beta-lactamase genes. As an intelligent nanomedicine delivery platform, engineered bacteriophage enable precise pathogen elimination an through photocatalytic reactive oxygen species generation, immunomodulatory interventions, or controlled release of antibacterial drugs. Furthermore, oral administration of engineered bacteriophage facilitates microbiota modulation, which selectively eliminate intestinal pathogens while preserve beneficial commensal microbiota, thereby restoring microbial community balance and preventing complications associated with dysbiosis. Finally, we critically analyze persistent challenges including host strain matching complexity, evolution of bacterial resistance mechanisms, pharmacokinetic optimization requirements, optimal administration route selection, large-scale production quality control standards and clinical dosing determination protocols. Through multidisciplinary integration of synthetic biology, infectious disease medicine and immunology, future translational medicine studies of bacteriophage should establish comprehensive technical platforms encompassing rapid phage screening, intelligent rational design, rigorous in vivo evaluation and standardized clinical validation processes, ultimately advancing engineered bacteriophage from laboratory innovations to clinically approved therapeutics for effectively combating MDR bacterial infections.
5.Treatment Modalities and Long-Term Outcomes in Unruptured Vertebrobasilar Fusiform Aneurysms: A Nationwide Observational Cohort Study
Linggen DONG ; Dachao WEI ; Xiheng CHEN ; Mingtao LI ; Yang ZHAO ; Yong SUN ; Qingbin NIE ; Jun FENG ; Guomin XIAO ; Jinghua ZHOU ; Shengli HU ; Lifei FENG ; Lifeng QI ; Hongen LIU ; Geng GUO ; Yufang LI ; Renfu TIAN ; Jianghua YU ; Dianshi JIN ; Liang HAO ; Tian TIAN ; Shizhong ZHANG ; Yang WANG ; Liping LIU ; Ming LV
Journal of Stroke 2026;28(2):250-262
Background:
and Purpose Vertebrobasilar fusiform aneurysms (VBFAs) carry substantial morbidity and mortality, but optimal management for unruptured VBFAs remains unclear. We compared the safety and efficacy of conservative management (CM), stent-assisted coiling (SAC), and flow diverters (FDs) in patients with unruptured VBFAs, focusing on long-term prognosis.
Methods:
This study included data from a nationwide Chinese cohort of patients with vertebrobasilar dissecting aneurysms. Inverse probability of treatment weighting (IPTW) balanced confounders across groups. The primary outcome was poor prognosis (modified Rankin Scale score >2). Secondary outcomes included aneurysm rupture, ischemic stroke, compression symptoms, and VBFA-related deaths. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and sensitivity analyses were performed.
Results:
Among 1,115 patients with unruptured VBFAs, 838 (median age, 54 years; 655 men) were included. After IPTW, baseline characteristics were balanced. Median follow-up was 54 months. FD was associated with a lower risk of poor prognosis than CM (OR, 0.48 [95% CI, 0.30 to 0.77]; p=0.002), with no difference between CM and SAC. FD also reduced aneurysm rupture (OR, 0.20 [95% CI, 0.07 to 0.60]; p=0.004) and compression symptoms (OR, 0.30 [95% CI, 0.13 to 0.68]; p=0.004) versus CM. Time-to-event analyses further revealed significant differences in vertebral artery lesions and Type I–II VBFAs, whereas no significant differences were observed in basilar or vertebrobasilar junction lesions or in Type III–IV VBFAs.
Conclusions
Compared with CM, FD was associated with improved long-term outcomes in unruptured VBFAs, particularly in vertebral artery lesions and Type I–II VBFAs, although residual confounding cannot be excluded.
6.Differences in deltamethrin resistance and kdr gene mutation in Culex tritaeniorhynchus population in and outside the Yellow Sea wetland
Xiao-er ZHANG ; Zhi-ming WU ; Ye TIAN ; Qian CUI ; Yu-qian JI ; Huan WANG ; Shu-juan YANG ; Yi-chao ZHAO ; Yu WANG ; Hua-yu YIN ; Yu DING ; Guo-jin YAN ; Min-sen ZHAO ; Shou-gang ZHANG ; Bing-dong SONG ; Hong-na CHEN ; Jian GAO ; Wei-fang YANG ; Yu-fu ZHANG ; Hui LIU ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):101-107
Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.
7.Targeting GYS1: From Metabolic Regulatory Mechanisms to Precision Therapeutic Strategies
Jia-Nan ZHAO ; Yu-Xuan LI ; Jie ZHU ; Hong LI ; Xiao-Feng JIN
Progress in Biochemistry and Biophysics 2026;53(7):1807-1825
Glycogen synthase 1 (GYS1) is the rate-limiting enzyme responsible for glycogen synthesis in skeletal muscle, heart, brain, and other extrahepatic tissues, playing a central role in systemic energy homeostasis. The human GYS1 gene maps to chromosome 19q13.33, comprises 16 exons, and encodes a 737-amino-acid polypeptide that is highly conserved across mammals. GYS1 activity is subject to multilayered and precisely coordinated regulation. At the transcriptional level, the GYS1 promoter contains a hypoxia response element (HRE) that mediates HIF-1α-dependent induction under low-oxygen conditions, as well as a muscle-specific enhancer harboring MEF2 and MyoD binding sites that confers tissue-restricted expression. At the post-translational level, a hierarchical phosphorylation cascade serves as the primary activity switch: glycogen synthase kinase 3β (GSK3β) sequentially phosphorylates four C-terminal serine residues following casein kinase II priming, while protein kinase A (PKA) and AMP-activated protein kinase (AMPK) provide parallel inhibitory inputs at both N- and C-terminal sites. Dephosphorylation and reactivation are mediated by protein phosphatase 1 (PP1) through tissue-specific glycogen-targeting regulatory subunits such as PPP1R3A and PPP1R3B, which anchor PP1 to glycogen particles and direct its activity toward GYS1. The allosteric activator glucose-6-phosphate (G6P) binds at the dimer interface, simultaneously enhancing catalytic efficiency and promoting dephosphorylation susceptibility, thereby establishing a feed-forward activation loop that couples substrate availability to glycogen synthesis. Beyond phosphorylation, GYS1 is regulated by ubiquitination (mediated by the E3 ligase PJA1), acetylation, O-linked β-N-acetylglucosamine (O-GlcNAc) modification, and SUMOylation, which collectively modulate protein stability, subcellular localization, and protein-protein interactions. Epigenetic mechanisms, including CpG island methylation and histone acetylation dynamics, govern chromatin accessibility at the GYS1 locus, while muscle-specific microRNAs such as miR-1 and miR-206 fine-tune GYS1 expression at the post-transcriptional level. Dysregulation of GYS1 has been identified as a central pathogenic driver in a spectrum of human diseases. In inherited glycogen storage disorders—including Lafora disease, adult polyglucosan body disease (APBD), and Pompe disease—loss of upstream regulatory control leads to GYS1 hyperactivation and the accumulation of structurally abnormal or excessive glycogen, resulting in progressive neurodegeneration, myopathy, and multiorgan dysfunction. In type 2 diabetes mellitus (T2DM), impaired insulin signaling through the PI3K-AKT-GSK3β axis maintains GYS1 in a hyperphosphorylated inactive state in skeletal muscle, compromising postprandial glucose disposal and exacerbating hyperglycemia. In oncology, GYS1 exhibits context-dependent roles across multiple cancer types. In hepatocellular carcinoma, FMO2+ cancer-associated fibroblasts stabilize GYS1 by competitively inhibiting PJA1-mediated ubiquitination, and stabilized GYS1 subsequently activates NF‑κB/CCL19 signaling to promote tertiary lymphoid structure formation and enhance anti-PD-1 immunotherapy responsiveness. In clear cell renal cell carcinoma, GYS1 promotes tumor progression through non-canonical NF‑κB pathway activation via the scaffold protein RPS27A. In triple-negative breast cancer, GYS1 has been identified as a trigger of disulfidptosis and an activator of NF-κB signaling through non-enzymatic facilitation of IκBα degradation. In colorectal cancer, mitochondrial fission deficiency drives AMPK-dependent GYS1 upregulation and glycogen accumulation as a compensatory survival mechanism, while in cervical cancer, GYS1-maintained glycogen reserves fuel the pentose phosphate pathway to generate NADPH for ROS clearance, thereby conferring cisplatin resistance in cancer stem cells. Therapeutic strategies targeting GYS1 have gained substantial momentum across these disease contexts. For glycogen storage disorders, antisense oligonucleotides, small interfering RNAs (e.g., ABX1100), and small-molecule inhibitors (e.g., MZ-101) have demonstrated preclinical and early clinical efficacy in reducing pathological glycogen accumulation. For T2DM, pharmacological activation of GYS1 through GSK3β inhibition or enhancement of PP1-mediated dephosphorylation is being explored to restore insulin-stimulated glycogen synthesis. In cancer, GYS1-directed interventions—including targeted silencing to sensitize tumors to chemotherapy and immune microenvironment modulation to enhance immunotherapy—represent emerging precision oncology approaches. This review provides a comprehensive and integrated account of GYS1 gene structure, tissue-specific distribution, regulatory networks, and pathogenic roles in metabolic disorders and malignancies, with the aim of establishing a theoretical framework for the development of GYS1-targeted precision therapies.
8.The role of bile acid dynamics in inflammatory bowel disease and metabolic dysfunction-associated steatotic liver disease
Si-Rui Yu ; Run Sun ; Mei-Ya Shi ; Mei Yang ; Kun Chen ; Qiong Pan ; Ling Zhao ; Ming-Yue Wu ; Jin Chai
Liver Research 2026;10(1):35-50
The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is higher among individuals with inflammatory bowel disease (IBD) than in the general population. Emerging evidence indicates that the development of MASLD in patients with IBD may occur independently of traditional metabolic risk factors, suggesting a unique pathophysiological mechanism distinct from conventional MASLD pathways. Bile acids (BAs), which act as critical signaling molecules in enterohepatic circulation, play an essential role in maintaining gastrointestinal homeostasis through bidirectional gut–liver axis communication. These molecules are increasingly recognized as pivotal regulators in the progression of both MASLD and IBD. While previous studies have characterized the dynamics of BA in blood or fecal samples under both conditions, a comprehensive understanding of their metabolic profiles and the associated interactions within the gut–liver axis is still lacking. This review synthesizes current evidence from studies employing BA metabolomics to investigate IBD and MASLD. By focusing on BA signatures, we summarize conserved alterations between these two conditions and their potential mechanisms of disease progression. Our review advances understanding of BA-mediated pathways in IBD and MASLD, providing a foundation for assessing their roles in contributing to the pathogenesis of MASLD in patients with IBD.
9.Chinese Medicine in Treatment of Colorectal Cancer by Regulating Hedgehog Signaling Pathway: A Review
Conghui ZHAO ; Hui ZHAO ; Shuaike YU ; Miaoxin JIN ; Jinyi YANG ; Mingsan MIAO ; Li BAI
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(22):255-264
Colorectal cancer (CRC), as a highly prevalent malignant tumor worldwide, continues to rank among the leading malignancies in both incidence and mortality. At present, the clinical treatment of CRC mainly relies on surgery, radiotherapy, chemotherapy, and drug therapy. However, due to individual differences among patients and the emergence of drug resistance in cancer cells, the postoperative recurrence rate remains high, significantly affecting patient prognosis. In recent years, traditional Chinese medicine (TCM) has attracted extensive attention in the field of tumor prevention and treatment because of its therapeutic advantages of multi-component, multi-target, multi-pathway, and holistic regulation. Aberrant activation of the Hedgehog signaling pathway is closely associated with the occurrence of various cancers. Studies have shown that the Hedgehog signaling pathway plays a key regulatory role in the occurrence and development of CRC. This pathway regulates the expression of downstream target genes through glioma-associated oncogene homolog (GLI) transcription factors and participates in biological processes such as tumor cell proliferation, apoptosis, invasion, and metastasis. It exerts anti- CRC effects through mechanisms including inducing apoptosis of CRC cells, inhibiting cancer cell proliferation, reversing drug resistance, and suppressing epithelial-mesenchymal transition (EMT), thereby influencing the progression of CRC. This article systematically reviews the latest research progress in China and abroad and comprehensively discusses the molecular regulatory mechanisms of the Hedgehog signaling pathway in CRC. It particularly focuses on the specific mechanisms by which active components of Chinese medicine, such as alkaloids and terpenoids, and Chinese medicine compound formulas, such as Baitouwengtang and Zhizhenfang, exert anti-CRC effects by interfering with the Hedgehog-GLI signaling axis. By integrating and analyzing the molecular relationship between the Hedgehog signaling pathway and the pathological progression of CRC, and combining the TCM theories of "holistic concept" and "syndrome differentiation and treatment", this article explores new TCM therapeutic strategies based on the Hedgehog signaling pathway, with the aim of providing innovative theoretical foundations and practical guidance for the prevention and treatment of CRC with TCM.
10.Application of Carbon Nanoparticle-Manganese Dioxide Injection in Gastrointestinal Staining-Based Marking and Localization in Rats and Pigs
Wanlin CHEN ; Qingrui DONG ; Mengtao LI ; Nan LIN ; Hu ZHAO ; Zaizhong ZHANG ; Lingjun ZENG ; Pei LI ; Jin YANG ; Yu WANG ; Aiwen HUANG
Laboratory Animal and Comparative Medicine 2026;46(5):727-739
ObjectiveTo develop a carbon nanoparticle-manganese dioxide (CN-MnO2) injection integrating visually identifiable staining and magnetic resonance (MR) T1/T2 dual-modal imaging, and to systematically evaluate its physicochemical properties, critical quality attributes, biocompatibility, and efficacy for gastrointestinal marking and localization. MethodsCN-MnO2 was prepared using a mild liquid-phase in situ redox deposition strategy and characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential analysis, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The pH of CN-MnO2 was directly measured using a pH meter. The osmolality pressure of CN-MnO2 was determined by the freezing point depression method. The bacterial endotoxin was detected using the gel-clot Limulus amebocyte lysate test, which did not rely on absorbance readings. The appearance of the CN-MnO2 injection solution stored at 4 ℃ under light shielding and sealed for 0, 5, and 10 days was observed, and its hydrated particle size, polydispersity index, zeta potential, and pH were also measured. With gadopentetate dimeglumine (Gd-DTPA) as the positive control, different concentration gradients were established, and T1 and T2 relaxation times were measured to construct concentration-dependent plots of the longitudinal and transverse relaxation rates (R1 and R2) and calculate the corresponding relaxivities (r1 and r2), compare relaxivity performance, and determine the working concentration for subsequent in vivo experiments. Cytocompatibility was assessed using the methyl thiazolyl tetrazolium (MTT) assay and live/dead staining. Sixteen male 6-week-old SD rats were randomly assigned to an experimental group and a control group (n=8 per group) and subcutaneously injected with CN-MnO2 injection at a total Mn concentration of 0.80 mmol/L or an equal volume of normal saline, respectively. Short-term in vivo safety was evaluated by regular body weight monitoring, hematoxylin-eosin (HE) staining of major organs, hematological and serum biochemical analyses, inflammatory cytokine detection, and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. Eight male 5–6-month-old Bama minipigs were randomly assigned to a CN-MnO2 group (n=6) and a carbon nanoparticle suspension injection (CNSI) group (n=2). CN-MnO2 injection or CNSI was injected subserosally into the stomach, small intestine, and colon. Within 5 min after each injection, the maximum staining diameter at each injection site was measured and recorded. MR T1WI/T2WI scans were performed on days 3 and 7 after injection to evaluate MR visualization at the injection sites. At the end of observation, the injection sites and major organs were collected for histopathological evaluation by hematoxylin-eosin staining. ResultsCN-MnO2 appeared as a black suspension, with no obvious aggregation or sedimentation after standing at room temperature (20-25 ℃) for 15 days. Its average hydrodynamic diameter was approximately (228.7±15.3) nm, the polydispersity index was 0.184±0.021, and the zeta potential was (-24.6±2.8) mV. XPS showed that CN-MnO2 was mainly composed of C, O, and Mn, with oxygen accounting for approximately 68.82%. The Mn 2p spectrum exhibited two characteristic peaks at 642.4 and 653.1 eV. XRD indicated that low-crystallinity δ-MnO2 was dispersed within the carbon matrix. The pH was 6.82±0.06, the osmolality was (298.4±6.7) mOsm/kg, and the bacterial endotoxin level was below the detection limit. In vitro MR imaging showed a clear concentration-dependent response, with r1 and r2 values of 9.6 L·mmol-1·s-1 and 17.2 L·mmol-1·s-1, respectively, indicating favorable T1/T2 contrast performance superior to that of Gd-DTPA. At 0.80 mmol/L, CN-MnO2 showed no obvious cytotoxicity in vitro. Short-term safety evaluation in SD rats revealed no obvious inflammatory response, impairment of liver or renal function, or abnormal manganese accumulation in major organs. In Bama minipigs, the mean staining diameters of the CN-MnO2 group in the stomach, small intestine, and colon were (0.65±0.12) cm, (0.61±0.11) cm, and (0.58±0.10) cm, respectively, with no significant difference among the three injection sites (P>0.05). The overall mean staining diameter was smaller in the CN-MnO2 group than in the CNSI group (P<0.05). MR examinations showed that the injection sites were identifiable on both day 3 and day 7, with stronger signals observed on day 3. At the end of observation, no obvious pathological abnormalities were observed at the injection sites or in major organs. ConclusionA CN-MnO2 injection with uniform particle size and stable physicochemical properties can be successfully prepared. This formulation integrates visible gastrointestinal staining with MR T1/T2 dual-modal imaging, providing a new strategy for preoperative gastrointestinal marking and localization as well as precise intraoperative resection.


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