1.Sequence analysis of variable regions of human monoclonal anti-P immunoglobulin
Zhonghui GUO ; Dong XIANG ; Qin LI ; Ziyan ZHU
Chinese Journal of Blood Transfusion 2026;39(1):24-30
Objective: To identify the structure of the complementarity determining region (CDRs), the V(D)J rearrangement and somatic hypermutational characteristics of the heavy and light chains of a red blood cell blood group-specific monoclonal antibody. Methods: The hybridoma cell line secreting human IgM κ monoclonal anti-P antibody was used as the research object. Total RNA was extracted from cultured monoclonal cell line, and cDNA was obtained by reverse transcription PCR (RT-PCR) using random hexamers primers. It was then amplified and sequenced using primers specific for variable regions of the immunoglobulin heavy and light chains encoding the anti-P antibody. The sequences were aligned against the NCBI database using online Immunoglobulin BLAST (Ig-BLAST) tool. Results: The study determined the structure of the CDRs and framework regions (FRs) of the variable regions of human monoclonal anti-P immunoglobulin, as well as the characteristics of V(D)J rearrangement. Moreover, the closest VH, VD, and VJ germline alleles for the heavy chain and VL and VJ germline alleles for the light chain were also identified. The IgH gene rearrangment pattern of the monoclonal anti-P was IGHV6-1
* 01—IGHD5-18
02—IGHJ4
02 and IgL gene was IGκV1-12
01—IGκJ3
01. Nine base mutations occurred within the germline gene IGHV6-1
01 in variable region of heavy chain, whereas 5 base mutations were found in the germline gene IGκV1-12
01 in variable region of light chain, respectively. Conclusion: This study characterized the CDR structure in monoclonal antibody cell line targeting the high-frequency red blood cell P antigen, and provided a foundation for the construction of recombinant antibody expressing plasmids and transfomation of the immunoglobulin type.
2.Predictive model for severe adverse reaction associated with bevacizumab based on the global trigger tool and machine learning
Yongfei FU ; Xin LONG ; Hongzhen XU ; Jian TANG ; Xiangqing LI ; Yucheng LONG ; Dong QIN
China Pharmacy 2026;37(4):497-503
OBJECTIVE To confirm trigger items for adverse drug reaction (ADR) induced by bevacizumab, to identify and analyze the occurrence of related ADR, and to establish a predictive model for severe adverse reaction (SAR) caused by this drug. METHODS Based on the global trigger tool (GTT) theory, and referencing the GTT White Paper, drug package inserts and relevant literature, trigger items for bevacizumab-related ADR were confirmed using a single-round Delphi method. Utilizing these established items, electronic medical records of relevant patients at Guilin People’s Hospital from January 2020 to September 2024 were actively screened via the China Hospital Pharmacovigilance System. Pharmacists then identified and tallied the occurrence of bevacizumab-induced ADR. Data from patients with any positive trigger item served as the study subjects (divided into training and test sets at a ratio of 7∶3), candidate feature variables were selected from 39 related variables using the Boruta algorithm, and the multivariable Logistic regression analysis was performed with the occurrence of SAR as the dependent variable. Based on these candidate features, Logistic Regression, Extreme Gradient Boosting, Light Gradient Boosting Machine, Random Forest, and Categorical Boosting models were constructed. Model performance was evaluated using metrics including the area under the curve (AUC) of receiver operating characteristic curve and recall rate. The Shapley Additive exPlanations (SHAP) method was applied to analyze and interpret the contribution of each variable. A nomogram was constructed based on the optimal model. RESULTS A total of 38 trigger items for active monitoring of bevacizumab-related ADR were determined, comprising 17 laboratory indicators, 13 clinical manifestations, and 8 intervention measures. In total, 483 patients with positive trigger items were included, and 318 patients with bevacizumab-induced ADR were identified, including 83 SARs. The positive predictive values for the trigger items and cases were 43.57% (708/1 625) and 63.84% (318/483), respectively. Bevacizumab-induced ADR involved 7 systems/organs, with the hematological system being the most frequently involved (64.15%). The Boruta algorithm selected 7 vari ables: serum potassium, hematocrit, albumin-to-globulin ratio, prealbumin, hypertension history, age and red blood cell count. Multivariable Logistic regression showed that elevated serum potassium levels were associated with a decreased risk of bevacizumab-induced SAR (OR=0.234, P =0.002), while a history of hypertension (OR=2.642, P =0.006) and increased age (OR=1.040, P =0.025) were associated with an increased risk. The Logistic Regression model demonstrated superior performance with higher AUC, F1 score and recall rate (0.761, 0.447, 0.607), compared to other models. SHAP evaluation results indicated that variables such as serum potassium, hematocrit, and age ranked highest in importance. CONCLUSIONS Totally 38 trigger entries have been successfully identified for active screening of bevacizumab-related ADR. Elevated serum potassium levels are a protective factor against bevacizumab-induced SAR, whereas the hypertension history and increased age are risk factors. The Logistic Regression model is the optimal predictive model.
3.Applications of Lactoferrin and Its Nanoparticles in Cancer Therapy
Wen-Tian YUE ; Shu-Rong HE ; Qin AN ; Yun-Xia ZOU ; Wen-Wen DONG ; Qing-Yong MENG ; Ya-Li ZHANG
Progress in Biochemistry and Biophysics 2026;53(2):342-355
Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.
4.Applications of Lactoferrin and Its Nanoparticles in Cancer Therapy
Wen-Tian YUE ; Shu-Rong HE ; Qin AN ; Yun-Xia ZOU ; Wen-Wen DONG ; Qing-Yong MENG ; Ya-Li ZHANG
Progress in Biochemistry and Biophysics 2026;53(2):342-355
Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.
5.Effect and mechanism of Xintong Granules in ameliorating myocardial ischemia-reperfusion injury in rats by regulating gut microbiota.
Yun-Jia WANG ; Ji-Dong ZHOU ; Qiu-Yu SU ; Jing-Chun YAO ; Rui-Qiang SU ; Guo-Fei QIN ; Gui-Min ZHANG ; Hong-Bao LIANG ; Shuai FENG ; Jia-Cheng ZHANG
China Journal of Chinese Materia Medica 2025;50(14):4003-4014
This study investigates the mechanism by which Xintong Granules improve myocardial ischemia-reperfusion injury(MIRI) through the regulation of gut microbiota and their metabolites, specifically short-chain fatty acids(SCFAs). Rats were randomly divided based on body weight into the sham operation group, model group, low-dose Xintong Granules group(1.43 g·kg~(-1)·d~(-1)), medium-dose Xintong Granules group(2.86 g·kg~(-1)·d~(-1)), high-dose Xintong Granules group(5.72 g·kg~(-1)·d~(-1)), and metoprolol group(10 mg·kg~(-1)·d~(-1)). After 14 days of pre-administration, the MIRI rat model was established by ligating the left anterior descending coronary artery. The myocardial infarction area was assessed using the 2,3,5-triphenyltetrazolium chloride(TTC) staining method. Apoptosis in tissue cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL) assay. Pathological changes in myocardial cells and colonic tissue were observed using hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), creatine kinase MB isoenzyme(CK-MB), and cardiac troponin T(cTnT) in rat serum were quantitatively measured using enzyme-linked immunosorbent assay(ELISA) kits. The activities of lactate dehydrogenase(LDH), creatine kinase(CK), and superoxide dismutase(SOD) in myocardial tissue, as well as the level of malondialdehyde(MDA), were determined using colorimetric assays. Gut microbiota composition was analyzed by 16S rDNA sequencing, and fecal SCFAs were quantified using gas chromatography-mass spectrometry(GC-MS). The results show that Xintong Granules significantly reduced the myocardial infarction area, suppressed cardiomyocyte apoptosis, and decreased serum levels of pro-inflammatory cytokines(TNF-α, IL-1β, and IL-6), myocardial injury markers(CK-MB, cTnT, LDH, and CK), and oxidative stress marker MDA. Additionally, Xintong Granules significantly improved intestinal inflammation in MIRI rats, regulated gut microbiota composition and diversity, and increased the levels of SCFAs(acetate, propionate, isobutyrate, etc.). In summary, Xintong Granules effectively alleviate MIRI symptoms. This study preliminarily confirms that Xintong Granules exert their inhibitory effects on MIRI by regulating gut microbiota imbalance and increasing SCFA levels.
Animals
;
Gastrointestinal Microbiome/drug effects*
;
Rats
;
Male
;
Myocardial Reperfusion Injury/genetics*
;
Drugs, Chinese Herbal/administration & dosage*
;
Rats, Sprague-Dawley
;
Apoptosis/drug effects*
;
Humans
;
Tumor Necrosis Factor-alpha/metabolism*
;
Interleukin-6/genetics*
;
Malondialdehyde/metabolism*
6.Mechanism of puerarin improving myocardial contractile function in myocardial hypertrophy by inhibiting ferroptosis via Nrf2/ARE/HO-1 signaling pathway.
Yan-Dong LIU ; Wei QIAO ; Zhao-Hui PEI ; Guo-Liang SONG ; Wei JIN ; Wei-Bing ZHONG ; Qin-Qin DENG
China Journal of Chinese Materia Medica 2025;50(16):4679-4689
This study aims to explore the specific mechanism by which puerarin inhibits ferroptosis and improves the myocardial contractile function in myocardial hypertrophy through the nuclear factor erythroid 2-related factor 2(Nrf2)/antioxidant response element(ARE)/heme oxygenase-1(HO-1) signaling pathway. The hypertrophic cardiomyocyte model was established using phenylephrine, and H9c2 cells were divided into control group, model group, puerarin group, and puerarin+ML385 group. Cell viability and surface area were detected by cell counting kit-8(CCK-8) and immunofluorescence experiments. The mitochondrial membrane potential and Ca~(2+) concentration were measured. The ferroptosis-related indicators were detected by biochemical and fluorescence staining methods. The expression of proteins related to ferroptosis and the Nrf2/ARE/HO-1 signaling pathway was detected by Western blot. A myocardial hypertrophy model was established, and 40 rats were randomly divided into sham group, model group, puerarin group, and puerarin+Nrf2 inhibitor(ML385) group, with 10 rats in each group. Echocardiogram, hemodynamic parameters, and myocardial hypertrophy parameters were measured. Histopathological changes of myocardial tissues were observed by hematoxylin and eosin(HE) staining and Masson staining. Biochemical methods, enzyme-linked immunosorbent assay(ELISA), and fluorescence staining were used to detect inflammatory factors and ferroptosis-related indicators. Immunohistochemistry was used to detect the expression of proteins related to ferroptosis and the Nrf2/ARE/HO-1 signaling pathway. Cell experiments showed that puerarin intervention significantly enhanced the viability of hypertrophic cardiomyocytes, reduced their surface area, and restored mitochondrial membrane potential and Ca~(2+) homeostasis. Mechanism studies revealed that puerarin promoted Nrf2 nuclear translocation, upregulated the expression of HO-1, solute carrier family 7 member 11(SLC7A11), and glutathione peroxidase 4(GPX4), and decreased malondialdehyde(MDA), reactive oxygen species(ROS), and iron levels. These protective effects were reversed by ML385. In animal experiments, puerarin improved cardiac function in rats with myocardial hypertrophy, alleviated myocardial hypertrophy and fibrosis, inhibited inflammatory responses and ferroptosis, and promoted nuclear Nrf2 translocation and HO-1 expression. However, combined intervention with ML385 led to deterioration of hemodynamics and a rebound in ferroptosis marker levels. In conclusion, puerarin may inhibit cardiomyocyte ferroptosis through the Nrf2/ARE/HO-1 signaling pathway, thereby improving myocardial contractile function in myocardial hypertrophy.
Animals
;
NF-E2-Related Factor 2/genetics*
;
Rats
;
Ferroptosis/drug effects*
;
Signal Transduction/drug effects*
;
Isoflavones/pharmacology*
;
Male
;
Rats, Sprague-Dawley
;
Cardiomegaly/genetics*
;
Myocytes, Cardiac/metabolism*
;
Antioxidant Response Elements/drug effects*
;
Myocardial Contraction/drug effects*
;
Heme Oxygenase-1/genetics*
;
Cell Line
7.Early clinical outcomes of 3D-printed individualised customised prostheses in hip revision combined severe bone defect.
Hong-Ping WANG ; Ming-You WANG ; Xiao-Qin YANG ; Zhuo-Dong TANG ; Xun-Zhou SONG ; Yu-Ping LAN
China Journal of Orthopaedics and Traumatology 2025;38(2):163-169
OBJECTIVE:
To explore the early clinical outcomes of 3D printed individualised customised prostheses for in hip revision in patients with combined severe bone defects.
METHODS:
Twenty-two patients from January 2021 to May 2023 underwent hip revision using 3D printed personalised customised prostheses were retrospective analyzed, including 10 males and 12 females, age 28 to 78 with a mean of (58.9±12.8) years old. All of patients were combined with severe bone defects (Parprosky type Ⅲ). Among of them, 9 patients had periprosthetic infections and 13 patients had aseptic prosthesis loosening. All patients were treated with a 3D printed personalised prosthesis protocol, patients with the periprosthetic infection received a second stage revision after infection control. The operation time, preoperative waiting time, intraoperative and postoperative complications were recorded, and the clinical efficacy were evaluated at the final follow-up using the visual analogue scale (VAS) for pain, the Harris hip score.
RESULTS:
One patient was lost to follow-up and the remaining 21 patients were followed up for 10 to 15 with a mean of (12.91±1.44) months after surgery. All patients completed surgery as planned, with an operative time of 135 to 390 with a mean of (165.4±39.3) minutes and a preoperative waiting time of 7 to 16 with a mean of (10.5±3.3) days. Regarding patient complications:one patient had a severe intraoperative periprosthetic femoral fracture due to the combination of severe osteoporosis; one patient had an intraoperative greater trochanteric femur fracture. At the latest follow-up, all patients had good position of the custom-made prosthesis and no loosening of the prosthesis;all patients had good wound healing and no local redness or swelling. The total Harris score at the final follow-up (85.86±7.04) was significantly improved compared to the preoperative (44.86±2.36), P<0.001. The VAS at the last follow-up (2.19±0.87) was significantly improved compared with preoperative (7.41±0.96), P<0.001.
CONCLUSION
The clinical efficacy of 3D-printed personalised customised prosthesis in combined severe bone defect hip revision is satisfactory, but due to the increased preoperative waiting time of the patients and certain risks, certain indications should be mastered when applying in the clinic.
Humans
;
Male
;
Female
;
Printing, Three-Dimensional
;
Middle Aged
;
Aged
;
Adult
;
Retrospective Studies
;
Hip Prosthesis
;
Arthroplasty, Replacement, Hip
;
Reoperation
;
Prosthesis Design
;
Treatment Outcome
8.Impact of human papillomavirus and coinfection with other sexually transmitted pathogens on male infertility.
Xin FAN ; Ya XU ; Li-Feng XIANG ; Lu-Ping LIU ; Jin-Xiu WAN ; Qiu-Ting DUAN ; Zi-Qin DIAN ; Yi SUN ; Ze WU ; Yun-Hua DONG
Asian Journal of Andrology 2025;27(1):84-89
This study primarily aimed to investigate the prevalence of human papillomavirus (HPV) and other common pathogens of sexually transmitted infections (STIs) in spermatozoa of infertile men and their effects on semen parameters. These pathogens included Ureaplasma urealyticum, Ureaplasma parvum, Chlamydia trachomatis, Mycoplasma genitalium , herpes simplex virus 2, Neisseria gonorrhoeae, Enterococcus faecalis, Streptococcus agalactiae, Pseudomonas aeruginosa , and Staphylococcus aureus . A total of 1951 men of infertile couples were recruited between 23 March 2023, and 17 May 2023, at the Department of Reproductive Medicine of The First People's Hospital of Yunnan Province (Kunming, China). Multiplex polymerase chain reaction and capillary electrophoresis were used for HPV genotyping. Polymerase chain reaction and electrophoresis were also used to detect the presence of other STIs. The overall prevalence of HPV infection was 12.4%. The top five prevalent HPV subtypes were types 56, 52, 43, 16, and 53 among those tested positive for HPV. Other common infections with high prevalence rates were Ureaplasma urealyticum (28.3%), Ureaplasma parvum (20.4%), and Enterococcus faecalis (9.5%). The prevalence rates of HPV coinfection with Ureaplasma urealyticum, Ureaplasma parvum, Chlamydia trachomatis, Mycoplasma genitalium , herpes simplex virus 2, Neisseria gonorrhoeae, Enterococcus faecalis, Streptococcus agalactiae , and Staphylococcus aureus were 24.8%, 25.4%, 10.6%, 6.4%, 2.4%, 7.9%, 5.9%, 0.9%, and 1.3%, respectively. The semen volume and total sperm count were greatly decreased by HPV infection alone. Coinfection with HPV and Ureaplasma urealyticum significantly reduced sperm motility and viability. Our study shows that coinfection with STIs is highly prevalent in the semen of infertile men and that coinfection with pathogens can seriously affect semen parameters, emphasizing the necessity of semen screening for STIs.
Humans
;
Male
;
Infertility, Male/epidemiology*
;
Coinfection/microbiology*
;
Papillomavirus Infections/virology*
;
Adult
;
Sexually Transmitted Diseases/complications*
;
China/epidemiology*
;
Staphylococcus aureus/isolation & purification*
;
Chlamydia trachomatis/isolation & purification*
;
Prevalence
;
Mycoplasma genitalium/isolation & purification*
;
Ureaplasma urealyticum/isolation & purification*
;
Neisseria gonorrhoeae/isolation & purification*
;
Enterococcus faecalis/isolation & purification*
;
Streptococcus agalactiae/isolation & purification*
;
Herpesvirus 2, Human/genetics*
;
Pseudomonas aeruginosa/isolation & purification*
;
Semen/virology*
;
Sperm Motility
;
Spermatozoa/microbiology*
;
Human Papillomavirus Viruses
9.Three-dimensional finite element analysis of digital wire loop space maintainers for missing deciduous teeth.
Lijuan MA ; Yonghui TENG ; Yong WANG ; Yijiao ZHAO ; Xinyue ZHANG ; Qingzhao QIN ; Dong YIN
Journal of Peking University(Health Sciences) 2025;57(2):376-383
OBJECTIVE:
To establish a three-dimensional finite element model of a digital wire loop space maintainer for the mandible and primary tooth loss, in order to investigate the stress, deformation, and shear force experienced by patients with the loss of the second primary molar when wearing the wire loop space maintainer.
METHODS:
Cone beam computed tomography (CBCT) scans were performed on the patients to create a digital model of the mandible with the absence of the second primary molar using Mimics 21.0 software. A digital model integrating the crown's retention and the wire loop structure of the full crown and ring wire loop space maintainer was constructed using pediatric space maintainer design software, utilizing three different materials: cobalt-chromium alloy, polyether ether ketone (PEEK), and titanium alloy. In ANSYS Work Beach 2023 R2 software, vertical loads of 70 N, tilted 45° along the long axis of the tooth loads of 70 N, and a 10 N load on the surface of the wire loop were applied to the occlusal surfaces of models 46 and 84, simulating centric and lateral occlusions during chewing with the wire loop space maintainer in place. The stress states of the wire loop space maintainer and supporting teeth were analyzed.
RESULTS:
Under various loading conditions, the maximum principal stress of the ring wire loop space maintainer was significantly lower than that of the full crown. Stress contour maps indicated that the peak of the maximum principal stress occurred at the junction of the wire loop and crown structure, indicating that this area was more susceptible to fracture. The ring wire loop space maintainer made from PEEK material exhibited the lowest maximum shear stress on the internal organizational surfaces, with equivalent stresses of 23.18 MPa and 36.35 MPa for models 46 and 84, respectively. Stress contour maps demonstrated that the maximum stress on tooth 46 was located at its mesial, while the maximum stress on tooth 84 was situated near the root area on its distal, in contact with the wire loop space maintainer.
CONCLUSION
In cases of second primary molar loss, wearing the digital ring wire loop space maintainer can effectively distribute stress, and the ring wire loop space maintainer made from PEEK material reduces the stress experienced by supporting teeth to some extent, demonstrating its superiority in clinical application.
Finite Element Analysis
;
Humans
;
Tooth, Deciduous
;
Cone-Beam Computed Tomography
;
Space Maintenance, Orthodontic/methods*
;
Imaging, Three-Dimensional
;
Orthodontic Wires
;
Dental Stress Analysis
;
Mandible
;
Stress, Mechanical
10.A preclinical evaluation and first-in-man case for transcatheter edge-to-edge mitral valve repair using PulveClip® transcatheter repair device.
Gang-Jun ZONG ; Jie-Wen DENG ; Ke-Yu CHEN ; Hua WANG ; Fei-Fei DONG ; Xing-Hua SHAN ; Jia-Feng WANG ; Ni ZHU ; Fei LUO ; Peng-Fei DAI ; Zhi-Fu GUO ; Yong-Wen QIN ; Yuan BAI
Journal of Geriatric Cardiology 2025;22(2):265-269

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