1.TGF-β1-engineered Biomimetic Platelet Nanoparticles for Targeted Therapy of Ischemic Stroke
Li-Qi CHEN ; Tian-Fang KANG ; Guo-Jun HUANG ; Ting YIN ; Ai-Qing MA ; Lin-Tao CAI ; Hong PAN
Progress in Biochemistry and Biophysics 2026;53(3):697-710
ObjectivePost-ischemic acute inflammation and the subsequent persistent dysregulation of the immune microenvironment represent major pathological drivers that aggravate neuronal injury and severely restrict functional recovery following ischemic stroke. Although current reperfusion therapies partially restore blood flow, they fail to effectively modulate the secondary inflammatory cascade and oxidative stress, which remain critical barriers to neurological restoration. To address this challenge, this study aimed to engineer and systematically evaluate a biomimetic nanosystem composed of transforming growth factor-β1 (TGF-β1)-loaded platelet membrane-camouflaged lipid nanoparticles (PLP). This nanosystem was designed to achieve dual lesion-targeted delivery and immune microenvironment remodeling. By verifying its spatiotemporal accumulation, anti-inflammatory activity, and neuroprotective efficacy, we sought to establish an integrated therapeutic strategy that simultaneously enables lesion targeting, immune regulation, and functional recovery after ischemic injury. MethodsThe physicochemical properties of PLP, including hydrodynamic particle size, zeta potential, structural stability, and morphology, were characterized using dynamic light scattering, zeta potential analysis, and transmission electron microscopy. The preservation of platelet membrane-derived adhesion and immunoregulatory proteins was confirmed by SDS-PAGE through comparative analysis of protein band profiles between PLP and native platelet membranes. The in vitro biological activities of PLP were evaluated using two complementary cellular models. LPS-induced M1-polarized RAW264.7 macrophages were employed to assess inflammatory modulation, while oxygen glucose deprivation/reperfusion (OGD/R)-induced BV2 microglial cells and SH-SY5Y neuronal cells were utilized to investigate neuroinflammatory regulation and neuronal protection. For in vivo validation, a transient middle cerebral artery occlusion (tMCAO) mouse model was established to mimic ischemia-reperfusion injury. The spatiotemporal biodistribution and lesion-targeting capability of the PLP were monitored through live fluorescence imaging. Therapeutic efficacy was comprehensively evaluated by triphenyltetrazolium chloride (TTC) staining, glial fibrillary acidic protein (GFAP) immunofluorescence analysis, body weight monitoring, and neurological severity score (NSS) assessment. ResultsPLP nanoparticles displayed a uniform spherical morphology, nanoscale particle size distribution, and stable negative surface charge, indicating favorable colloidal stability and circulation potential. SDS-PAGE results confirmed the effective retention of key platelet membrane proteins associated with endothelial adhesion, immune evasion, and inflammatory regulation, demonstrating the successful biomimetic construction. Optimal therapeutic concentrations were determined in OGD/R-induced BV2 cells, where PLP exhibited excellent cytocompatibility and anti-inflammatory activity.In vitro experiments demonstrated that PLP significantly inhibited the polarization of RAW264.7 macrophages toward the pro-inflammatory M1 phenotype and markedly reduced neuronal apoptosis under ischemia-reperfusion conditions. In vivo fluorescence imaging revealed that PLP rapidly accumulated in the ischemic brain hemisphere and maintained prolonged retention for up to 7 d, suggesting enhanced lesion-specific targeting and sustained drug release. Compared with control group, PLP treatment significantly reduced cerebral infarct volume, attenuated reactive astrogliosis, improved weight recovery, and accelerated neurological functional restoration, as reflected by significantly improved NSS scores. ConclusionThis study establishes a multifunctional biomimetic nanoplatform that integrates platelet membrane-mediated active targeting with the anti-inflammatory, antioxidative, and neuroprotective properties of TGF-β1. The PLP system enables rapid lesion homing and long-term retention while synergistically regulating the post-stroke inflammatory microenvironment by suppressing pro-inflammatory immune activation, reducing neuronal apoptosis, and limiting excessive astrocyte reactivity. Importantly, this study proposes a conceptually therapeutic paradigm that combines targeted delivery with immune microenvironment remodeling to achieve comprehensive neurovascular protection. These findings provide strong experimental evidence supporting the translational potential of biomimetic nanotherapeutics as next-generation precision interventions for ischemic stroke.
2.Research on The Genealogical Inference Efficiency of High-density SNPs
Jing LI ; Yi-Jie SUN ; Wen-Ting ZHAO ; Zi-Chen TANG ; Jing LIU ; Cai-Xia LI
Progress in Biochemistry and Biophysics 2026;53(3):740-753
ObjectiveThis study aims to explore the potential of different orders of magnitude single-nucleotide polymorphism (SNP) locus combinations for predicting distant kinship relationships. A high-density SNP locus set was constructed, and a comprehensive assessment of its inference capability was conducted. MethodsFirstly, we selected three commercial chip panels, CGA (Chinese genotyping array, Illumina), GSA (Global screening array, Illumina), Affy (23MF_V2 high-density SNP array, Affymetrix) and merged them after quality control, forming a high-density SNP locus panel(1 180 k). Secondly, we selected 161 samples and collected their peripheral blood samples by using whole-genome sequencing technology. Within this sample population, the levels of kinship relationships fully covered the range from level 1 to level 9, and the number of kinship pairs at each level was consistently maintained at over 50 pairs. From 161 samples data of whole-genome sequencing, the 1 180 k locus set was extracted, which is referred to as the high-density SNP locus set in the following text. The kinship inference was conducted using the identity-by-descent (IBD) algorithm with the selected optimal parameters. To comprehensively evaluate the performance of the high-density SNP locus set in kinship inference, we compared it with the three commercial chip panels, the intersection of these three chip loci, and the control sets constructed by randomly reducing the number of the high-density SNP locus set. Based on the changes in the IBD lengths, as well as the dynamic trends in prediction accuracy, we conducted a scientific assessment of the kinship inference capability of the high-density SNP locus set. ResultsAfter screening, a set of 1 184 334 autosomal SNPs was obtained. During the process of screening the optimal IBD length threshold, the result revealed that 0 cM, 1 cM, and 2 cM all demonstrated good applicability. However, to avoid the issue of a large amount of redundant information caused by setting a too low IBD length threshold, this study ultimately selected 2 cM as the optimal threshold. Compared with the average results of three chip panels, the high-density SNP locus set increased the total IBD length and the average IBD length across levels 1-9; the accuracy of the confidence interval for level 8 was 70.97%, which represented a 3.50% improvement; the average confidence interval accuracy for levels 1-8 was 91.39%, representing a 1.00% increase; and the false negative rates at levels 8 and 9 were reduced by 2.42% and 6.76%, respectively. The system efficacy of the high-density SNP locus set for kinship inference of first to eighth degree relationships reached 98.91%. Through random reduction of the high-density SNP locus set results, it is found that increasing the number of SNPs with the panel, the detection efficiency of IBD length showed a significant upward trend. At the same time, the overall trend in the accuracy of kinship relationship prediction as well as the confidence interval accuracy also indicated that both metrics steadily increased with the addition of more loci. ConclusionThe results show that the high-density SNPs panel significantly enhances the efficacy of distant kinship inference, accurately covering kinship degrees, with the average confidence interval accuracy for first to eighth degree relationships stably above 90%. The study finds that increasing the number of SNPs panel can improve the ability to predict distant kinship.
3.Pathological changes and macrophage polarization in the liver and spleen of mice infected with Angiostrongylus cantonensis
Xiaoyu QIN ; Yuchun CAI ; Yang HONG ; Fanna WEI ; Yahong HU ; Yumeng CAI ; Yuan HU ; Ting ZHANG ; Xiaojin MO ; Bin XU ; Yan LU ; Jiahui SUN ; Yan ZHOU ; Zelin ZHU ; Muxin CHEN
Chinese Journal of Schistosomiasis Control 2026;38(2):169-183
Objective To investigate the temporal changes in pathological damage and macrophage polarization in liver and spleen tissues of mice infected with Angiostrongylus cantonensis, and to preliminarily unravel the peripheral immune responses during the early stage of A. cantonensis infection. Methods Forty female BALB/c mice at ages of 6 to 8 weeks were randomly divided into four groups, including the control group and 7-, 14-, and 21-day infection groups, with 10 mice in each group. Each mouse in the infection groups was inoculated with 30 third-stage (L3) larvae of A. cantonensis by oral gavage, and five mice were randomly selected from each infection group on days 7, 14, and 21 post-infection, while mice in the control group were given the same volume of physiological saline and five mice were randomly selected from the control group on the day of oral gavage. Mouse liver and spleen tissues were sampled. The histopathological changes of mouse liver and spleen tissues were observed using hematoxylin and eosin (HE) staining, and the percentage of positive staining area and the co-localization positive rates of the macrophage surface antigens F4/80, CD86, and CD206 were quantified in mouse liver and spleen tissues using immunohistochemical and immunofluorescence staining. In addition, five mice were collected from each infection group on days 7, 14, and 21 post-infection, and five mice were collected from the control group on the day of oral gavage. Mouse liver and spleen tissues were sampled for detection of macrophage markers CD86 and CD206 and macrophage phenotyping using flow cytometry, and the expression of M1 macrophage markers, including inducible nitric oxide synthase (Nos2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and M2 markers, including arginase 1 (Arg1), mannose receptor C-type 1 (Mrc1) and chitinase-like protein 3 (Chil3) was quantified in mouse liver and spleen tissues using real-time quantitative PCR (RT-qPCR) assay. Results Proliferative lesions of the hepatocyte were observed in mouse liver tissues and the follicular structures of the mouse spleen white pulp were disrupted 21 days post-infection with A. cantonensis. Immunohistochemical staining showed that there were significant differences in the percentages of F4/80, CD86 and CD206 positive staining areas in the liver and spleen tissues among the four groups of mice (F = 242.40, 197.14, 183.19, 157.65, 242.35 and 146.24; all P values < 0.001), and the percentages of positive staining in the liver and spleen tissues of mice in the 14-day infection group [(4.45 ± 0.51)%, (3.74 ± 0.67)%, (8.32 ± 0.72)%, (16.56 ± 1.14)%, (11.62 ± 0.52)%, and (8.29 ± 0.72)%, respectively] and the 21-day infection group [(3.70 ± 0.11)%, (3.22 ± 0.43)%, (11.53 ± 1.03)%, (12.59 ± 1.05)%, (9.02 ± 0.83)%, and (11.67 ± 1.10)%, respectively] were higher than in the control group [(0.35 ± 0.16)%, (0.40 ± 0.02)%, (0.93 ± 0.05)%, (2.78 ± 0.26)%, (2.33 ± 0.20)%, and (1.85 ± 0.20)%, respectively] (all P values < 0.05). Immunofluorescence staining showed significant differences in the positive rates of F4/80 co-localization with CD86 and CD206 in mouse liver and spleen tissues among the four groups (F = 24.42, 25.28, 54.51 and 130.55; all P values < 0.001). Flow cytometry detected significant differences in the proportions of CD86+ and CD206+ macrophages in mouse liver and spleen tissues among the four groups (F = 67.98, 18.41, 29.77, 172.80; all P values < 0.001), and the proportions of CD206+ macrophages in the liver and spleen of the 21-day infection group were significantly higher than those in the control group [(9.25 ± 2.55)% vs (3.83 ± 0.72)%, and (4.22 ± 0.56)% vs (0.47 ± 0.18)%, respectively] (both P values < 0.05). In addition, RT-qPCR assay quantified significant differences in the relative mRNA expression of M1 macrophage markers (IL-1β, TNF-α and Nos2) and M2 macrophage markers (Arg1, Chil3 and Mrc1) in mouse liver and spleen tissues among the four groups (F = 41.30, 31.82, 199.33, 19.96, 62.01, 119.76, 23.67, 95.90, 72.27, 82.59, 123.41 and 29.75; all P values < 0.05). Conclusions A. cantonensis infection may cause progressive pathological damage in mouse liver and spleen tissues, accompanied by dynamic temporal changes in macrophage polarization. M1 macrophage polarization predominates at the early stage of A. cantonensis infection and shifts towards M2 polarization at the later stages, suggesting that M2 polarization may participate in immune regulation at late stages of A. cantonensis infection by suppressing excessive inflammatory responses and promoting tissue repair.
4.Central nervous system infection:Expert consensus on imaging examination standards(2024 edition)
Chen QIAO ; Ting LIU ; Jianming CAI ; Qing LU ; Weijun SITU ; Meng ZHENG ; Zhenying XIA ; Yuan QU ; Ting LIANG ; Guangping ZHENG ; Hongkai ZHANG ; Shengyuan LAI ; Hongjun LI
Chinese Journal of Medical Imaging Technology 2025;41(6):857-860
Imaging examination is a crucial part in diagnosis and treatment of central nervous system infection(CNSI),involving complex imaging sequences and parameters.This consensus was jointly written by multiple CNSI imaging experts in China,aimed to standardize imaging examination of CNSI.
5.Construction of predictive model for continuous renal replacement therapy in early stage of sepsis children
Xin YE ; Qiyin CAI ; Jiali HUANG ; Qin LIU ; Guanghui CHEN ; Chaofu QIN ; Ting LIANG
China Modern Doctor 2025;63(32):12-16
Objective To screen the predictors of early initiation of continuous renal replacement therapy(CRRT)in children with sepsis and construct a linear model,based on LASSO regression analysis.Methods A total of 55 children diagnosed with sepsis at Jiangmen Maternity and Child Health Care Hospital from April 2023 to February 2025.They were divided into CRRT group(n=17)and non-CRRT group(n=38)based on CRRT treatment usage.Using LASSO regression screening,predictive factors were identified and a Logistic regression model was established.The model's performance was evaluated using receiver operating characteristic(ROC)curve and calibration curve.Results There were significant differences in age,respiratory rate,body temperature,and mechanical ventilation between two groups(P<0.05).Through LASSO regression analysis,four independent predictors of respiratory rate,body temperature,blood glucose,and C-reactive protein were identified.The constructed model demonstrated an area under the ROC curve of 0.94(95%CI:0.87-1.00),indicating good calibration accuracy.Conclusion The column line model based on body temperature,respiratory rate,blood glucose and C-reactive protein can effectively predict the need for early initiation of CRRT in sepsis children.
6.Assay for detection of toxigenic Clostridioides difficile with combined microfluidic chip and immunochromatography technology
Hong-rui CHENG ; Xiao-jun SONG ; Yu CHEN ; Meng ZHANG ; Meng-ting CAI ; Kun ZHU ; Yu-lei TAI ; Shi-bo YING ; Da-zhi JIN
Chinese Journal of Zoonoses 2025;41(2):142-149
An assay was established for detection of toxigenic Clostridioides difficile by combining microfluidic chip analysis with immunochromatography,and its performance was evaluated and compared with those of the Xpert C.difficile/Epi and VIDAS CD AB tests.Primer pairs were designed according to the tcdB and tpi genes in C.difficile.The specificity,limit of detection,reproducibility,and stability were evaluated.A total of 215 stool samples from patients with diarrhea were collected and tested in parallel with the Xpert C.difficile/Epi,VIDAS CDAB,and our assay.C.difficile was isolated from samples,and the tcdB gene was identified when discrepant results were obtained from the three above assays.Our assay showed no cross-reaction with other diarrhea-associated pathogens.Its reproducibility was 100%in testing of two standard plasmids containing tcdB and tpi genes at two concentrations(105 and 102 copies/μL).Two standard plasmids were detected after the PCR and immunochromatography reagents had been stored for 3,6,9,and 12 months,and all the results were posi-tive.The limit of detection was 10 copies/μL for toxigenic C.difficile.Testing of 33 samples positive for C.difficile with our assay(33/215,15.3%)yielded findings statistically coherent with those of the Xpert C.difficile/Epi test(kappa value=0.965).The sensitivity,specificity,positive predictive value,and negative predictive value of our assay,with respect to Xpert C.difficile/Epi as the standard,were 94.3%,100.0%,100.0%,and 98.9%;these values were significantly higher than those of VIDAS CDAB(60.0%,98.9%,91.3%,and 92.7%)(Kappa=0.714,OR=157.50,95%CI:62.03-847.28,P=0.013).In conclusion,our newly developed assay is specific,stable,and reproducible,and may be used for rapid and accu-rate detection of toxigenic C.difficile.The assay could be used for C.difficile infection screening in outpatient and emergen-cy,community medical service center,and epidemiological settings.
7.Clinical Study on Guhong Injection in the Treatment of Coronary Microvascular Dysfunction
Haobo ZHANG ; Qihua WU ; Ting LAI ; Shufen WANG ; Hairong CAI ; Li CHEN ; Bojun CHEN ; Qingmin LI
Journal of Guangzhou University of Traditional Chinese Medicine 2025;42(1):44-50
Objective To investigate the clinical efficacy of Guhong Injection for the treatment of patients with coronary microvascular dysfunction(CMD)of qi stagnation and blood stasis syndrome.Methods Sixty cases of patients with CMD of qi stagnation and blood stasis syndrome who were admitted to Guangdong Provincial Hospital of Chinese Medicine from June 2021 to August 2022 were randomly divided into the control group and the trial group according to the random number table method,with 30 cases in each group.The control group was treated with conventional western medicine,and the trial group was treated with Guhong Injection on the basis of treatment for the control group.The course of treatment for the two groups covered 10 days.The changes in traditional Chinese medicine(TCM)syndrome scores,and levels of lipid indicators,serum inflammatory factors and endothelial factors in the two groups were observed before and after treatment.After treatment,the clinical efficacy of the two groups was evaluated.Results(1)During the trial,three cases in the control group and two cases in the trial group fell off and a total of 55 cases were finally included in the statistical analysis of efficacy,including 27 cases in the control group and 28 cases in the trial group.(2)After 10 days of treatment,the total effective rate of the trial group was 89.29%(25/28),and that of the control group was 40.74%(11/27),and the intergroup comparison(tested by chi-square test)showed that the therapeutic efficacy of the trial group was significantly superior to that of the control group(P<0.01).(3)After treatment,the TCM syndrome scores of patients in both groups were decreased compared with those before treatment(P<0.05),and the decrease in the trial group was significantly superior to that in the control group(P<0.01).(4)After treatment,the levels of lipid indicators triglyceride(TG),total cholesterol(TC),and low-density lipoprotein cholesterol(LDL-C)in the two groups of patients were decreased compared with those before treatment(P<0.05),and the level of high-density lipoprotein cholesterol(HDL-C)was increased compared with that before treatment(P<0.05).The intergroup comparison showed that the decrease of TG,TC,and LDL-C levels as well as the increase of HDL-C level in the trial group was significantly superior to that in the control group(P<0.05 or P<0.01).(5)After treatment,the serum levels of inflammatory factors high-sensitivity C-reactive protein(hs-CRP),interleukin 6(IL-6)and tumor necrosis factor α(TNF-α)in the two groups of patients were decreased compared with those before treatment(P<0.05),and the decrease in the trial group was significantly superior to that in the control group(P<0.01).(6)After treatment,the serum level of endothelial factor nitric oxide(NO)in the two groups of patients was increased(P<0.05)and the serum endothelin 1(ET-1)level was decreased compared with that before treatment(P<0.05),and the increase of serum NO level,as well as the decrease of serum ET-1 level in the trial group was significantly superior to that in the control group(P<0.05 or P<0.01).Conclusion Based on the conventional treatment in western medicine,the application of Guhong Injection in the treatment of patients with CMD of qi stagnation and blood stasis syndrome exerts remarkable efficacy,which can effectively alleviate the symptoms,regulate the levels of blood lipids,reduce the inflammatory response,and improve the endothelial function.
8.An outbreak of influenza A H1N1 in a specialized psychiatric hospital
Junting XIAO ; Paihan CHEN ; Ting HU ; Ying ZHOU ; Weinan LI ; Yebin CHEN ; Zixi CAI ; Gengna CHEN
Chinese Journal of Infection Control 2025;24(7):1001-1005
Objective To analyze the epidemiological characteristics and risk factors of an outbreak of influenza A H1N1 in a specialized psychiatric hospital in Shantou City,Guangdong Province,provide scientific basis for the pre-vention and control of respiratory infectious diseases in psychiatric health institutions.Methods Data of infection cases in this hospital in May 1-27,2024 were collected with on-site epidemiological investigation method,and were analyzed with descriptive epidemiological methods.The specimens of the cases were performed nucleic acid testing by reverse transcription polymerase chain reaction(RT-PCR)method.Results A total of 43 influenza-like cases in this outbreak have been reported,with an incidence of 16.67%,including 42 hospitalized patients and 1 healthcare worker.Among the 42 hospitalized patients,there were 41 males,with an incidence of 35.04%and 1 female with an incidence of 2.22%,there was a statistically significant difference in incidence between hospitalized patients of different genders(x2=18.23,P<0.001).The epidemic curve shows that after the first case appeared on May 8,2024,the number of cases increased significantly from May 13,and reached its peak on May 17(n=17).31 pa-tients' throat swab specimens were collected,out of which 29(93.55%)were positive for influenza A H1N1 virus nucleic acid and 2(6.45%)were negative.Conclusion This epidemic is an outbreak of influenza A H1N1 in a psy-chiatric health institution,the epidemic curve shows a point source human-to-human transmission mode.Failure to effectively identify and isolate cases in the early stage can lead to the spread of the epidemic across floors and wards.It is necessary to regularly organize hospitalized patients and healthcare workers to receive influenza vaccines,strict-ly implement the health monitoring system,strengthen the control of external personnel,and enhance the early de-tection and emergency response capabilities for infectious disease outbreaks.
9.Clinical phenotype and pathogenic variation analysis of an autosomal dominant deafness family
Mengfei CAI ; Ting ZHANG ; Wanli HE ; Mengli ZHANG ; Xiaosai ZHANG ; Hongen XU ; Bei CHEN
Journal of Audiology and Speech Pathology 2025;33(6):520-524
Objectiv To investigate an autosomal dominant non-syndromic hearing loss family pedigree com-prehensively,aiming to precisely define its clinical phenotypes and uncover the underlying molecular genetic etiolo-gy.Methods A detailed interrogation of the proband's medical history and family history was conducted.Physical examinations,audiological assessments and temporal bone CT scans were performed.Genomic DNA was extracted from the peripheral blood of the proband(Ⅳ-8)for whole-exome sequencing(WES).Subsequently,candidate vari-ants identified through WES were validated among family members using Sanger sequencing.Results There were 36 individuals in 4 generations in this family pedigree,showing autosomal dominant inheritance.Among them,16 individuals presented with progressive hearing loss.Audiological examinations were completed for 13 of them,re-vealing normal hearing in three individuals(Ⅲ-1,Ⅲ-1 1,Ⅳ-4)and bilateral symmetric hearing loss of varying se-verity in the remaining ten(Ⅱ-2,Ⅱ-4,Ⅱ-10,Ⅲ-4,Ⅲ-10,Ⅲ-13,Ⅲ-14,Ⅳ-1,Ⅳ-7,Ⅳ-8),and the degree of hearing loss was related to age.WES of Ⅳ-8 revealed that she carried the variant NM_199330.2(HOMER2):c.1064 A>G(p.Ter354Trpext10),and Sanger sequencing verified the variation at this site.Peripheral blood samples of 18 individuals in this family were collected in total.All affected individuals(Ⅱ-2,Ⅱ-4,Ⅱ-10,Ⅲ-4,Ⅲ-9,Ⅲ-10,Ⅲ-13,Ⅲ-14,Ⅳ-1,Ⅳ-7,Ⅳ-8)carried the HOMER2 c.1064 A>G variant,except for one young member(Ⅳ-6)who had not yet developed hearing loss.Unaffected individuals(Ⅱ-5,Ⅲ-1,Ⅲ-5,Ⅲ-11,Ⅳ-2,Ⅳ-4)lacked the variant,demonstrating complete cosegregation of genotype and phenotype.According to ACMG guide-lines,this variant was classified as likely pathogenic(PM2+PP1+PM4).Conclusion The c.1064 A>G(p.Ter354Trpext10)variant of the HOMER2 gene is the molecular genetic etiology of this hereditary deafness family pedigree.
10.Finite element analysis of treatment for Sanders type IIB intra-articular calcaneal fracture by percutaneous screws
Yixuan CHEN ; Jiachen WU ; Chang LIU ; Tianyi WU ; Shang GUO ; Jiangyu CAI ; Ting WANG ; Mingjie TANG ; Zhongmin SHI ; Xin MA
Chinese Journal of Orthopaedics 2025;45(19):1241-1250
Objective:To evaluate the stability of percutaneous screw fixation for minimally invasive treatment of intra-articular calcaneal fractures using three-dimensional finite element analysis.Methods:CT scan was performed on the calcaneus of a normal adult for three-dimensional reconstruction. The DICOM data were imported into Mimics software to establish a model of a Sanders type IIB intra-articular calcaneal fracture. Based on the Essex-Lopresti classification of posterior facet morphology, the model was subdivided into two subtypes: tongue-type and depression-type. The calcaneus was divided into four fragments: sustentaculum tali, posterior tuberosity, anterior process (three points), and posterior articular surface (one surface). Two types of fixation methods, classical lateral anatomical plates and combinations of percutaneous screws, were simulated and performed. A three-dimensional finite element analysis was conducted by applying a stress combination of 420 N on the posterior subtalar articular surface, 200 N on the middle subtalar articular surface, and 300 N at the Achilles tendon insertion point. The maximum displacement and von Mises stress values of each bone fragment and implant were recorded to evaluate the biomechanical stability. For clinical validation, 34 patients with Sanders type IIB calcaneal fractures from Orthopedics Department of the Sixth Affiliated People's Hospital of Shanghai Jiao Tong University were treated with percutaneous reduction and screw fixation using the following configurations.Results:Under simulated stress, the A4 group with medial support screws in the tongue-type fracture subgroup demonstrated minimal overall calcaneal displacement (0.22 mm) and internal fixation displacement (0.14 mm). For the depression-type, the B2 group with medial support screws showed lower maximum stress in the calcaneus and internal fixation, at 22.04 MPa and 41.14 MPa, respectively, along with the lowest overall displacement (0.14 mm). The peak stress of all groups of implants remained below the material yield strength. The A4 and B2 protocols were applied to 15 cases of tongue-type calcaneal fractures and 19 cases of collapse-type calcaneal fractures. At the final follow-up The American Orthopaedic Foot & Ankle Society ankle-hindfoot score scale was 86.1±5.82 and 87.2±5.18, respectively, while the visual analog scale for pain was 1.60±1.24 and 1.58±1.02, respectively.Conclusions:Percutaneous screw fixation provided reliable stability for Sanders type IIB calcaneal fractures. The fixation configuration incorporating a medial support screw offers superior biomechanical performance in both tongue-type and depression-type fractures, representing an optimized minimally invasive technique with strong clinical applicability.

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