Objective:To explore the clinical application value of a combined model based on the radiomics features of magnetic resonance imaging(MRI)and MRI signs in predicting recurrence after radical resection for hepatocellular carcinoma(HCC).Methods:A retrospective analysis was conducted on the imaging data of 100 patients with radical resection for HCC who admitted to Zibo 148 Hospital from May 2016 to May 2020.All patients underwent abdominal enhanced MRI examination before surgery,and they were followed up for at least 2 years after the surgery.They were randomly divided into training group(70 cases)and verification group(30 cases)as a ratio of 7:3.According to the postoperative follow-up results,the training group existed 12 cases of recurrence and 58 cases without recurrence,and the verification group existed 5 cases of recurrence and 25 cases without recurrence.The 3D-slicer software was used to extract radiomics features of preoperative MRI images of each HCC patient.The intra-group correlation coefficient(ICC)of the extracted imaging features of the observers was calculated.The maximum related minimum redundancy(mRMR)algorithm and LASSO regression were selected to analyze the established radiomics labels after dimensionality reduction and screening.Univariate and multivariate logistic regression analysis were used to screen the independent risk factors of predicting recurrence in MRI signs,and they were used respectively to construct radiomics models with the radiomics labels of plain scan,arterial phase,portal phase and hepatobiliary phase.The receiver operating characteristic(ROC)curve was used to assess the diagnostic efficacy of each radiomics model in predicting recurrence.Results:The ICC range of two physicians in selecting radiomics features from the MRI images of all patients were between 0.903 and 0.957,which consistency was favorable(ICC≥0.9).Compared with other predictive models,the highest area under curve(AUC)values of ROC curve of the radiomics model of plain scan of training group[0.951(95%CI:0.901-1.000)]and verification group[0.968(95%CI:0.917-1.000)]were respectively 0.951 and 0.968 in predicting recurrence after radical resection for liver cancer.Conclusion:The combined model that is constructed on the basis of MRI radiomics features has favorable predictive value for the recurrence of patients after radical resection for HCC.Among of them,the radiomics model of plain scan has a certain guiding role in the clinical implementation of personalized treatment plans under the absence of enhancement,and in underdeveloped areas.

OBJECTIVE To investigate the impact of lysosomal associated membrane protein 2b(Lamp2b)modification on the mucosal immune efficacy of engineered exosome-based vaccines.METHODS In vitro experiments:The murine dendritic cell line DC2.4 was transfected with a plasmid encoding the Lamp2b-RBD fusion protein.Real-time quantitative PCR and Western blotting were employed to assess Lamp2b-RBD expressions,flow cytometry was used to evaluate the proportion of Lamp2b-RBD-positive cells,and immunofluorescence staining was performed to determine their membrane localization.Exosomes were isolated via ultracentrifugation,and their morphology and particle size distribution were examined using transmission electron microscopy and nanoparticle tracking analysis.Western blotting was applied to confirm exosomal marker proteins[cluster of differentiation 9(CD9),CD63,ALG-2-interacting protein X(Alix),and Golgi marker GM130]and Lamp2b-RBD expression.In vivo experiments:① Female BALB/c mice were divided into the Lamp2b-RBD-Exo group and the lipid nanoparticle(LNP)group,and administered intratracheally for mucosal immunization.Pulmonary reten-tion was assessed by immunofluorescence staining.② Female BALB/c mice were divided into three groups:placebo group(PBS group),Lamp2b-RBD-Exo intratracheal administration group,and Lamp2b-RBD-Exo intramuscular injection group(im).Immunizations were performed on days 0 and 14,and on days 7 and 21.The titers of RBD-specific immunoglobulin G(IgG)in serum and RBD-specific IgA and IgG antibodies in bronchoalveolar lavage fluid were determined by enzyme-linked immunosor-bent assay(ELISA).RESULTS In vitro experiments:Lamp2b-RBD-positive cells accounted for 71.16％.Lamp2b-RBD mRNA levels were upregulated 1 979-fold compared with controls,with Lamp2b-RBD proteins localized on the cell membrane.Purified engineered exosomes displayed regular morphology,expressed CD9,CD63,and Alix but not GM130,had an average diameter of approximately 124 nm,and carried 3 009 pg of RBD protein per 1×109 exosomes.In vivo experiments:At 4 h after administra-tion,fluorescence signals were observed in the lung tissues of both the Lamp2b-RBD-Exo and LNPs groups.At 24 h,the fluorescence signal in the LNPs group shifted to the liver,while in the Lamp2b-RBD-Exo group,the fluorescence expanded from the trachea to the bronchioles and lung tissue,showing significantly better distribution and retention capacity than the LNPs group.Seven days after immuniza-tion,both the Lamp2b-RBD-Exo and Lamp2b-RBD-Exo(im)groups induced RBD-specific IgG antibody titers.At 21 days after immunization,Lamp2b-RBD-Exo elicited a higher level of RBD-specific immune response,with serum IgG titers reaching 1∶8 100 and bronchoalveolar lavage fluid(BALF)IgA titers reaching 1∶300.No RBD-specific IgA antibody titers were detected in the BALF of the Lamp2b-RBD-Exo(im)group.CONCLUSION Lamp2b-RBD modification enables efficient RBD protein loading and enhances pulmonary retention of engineered exosomes,thereby inducing potent antigen-specific mucosal immune responses.

OBJECTIVE To investigate the impact of lysosomal associated membrane protein 2b(Lamp2b)modification on the mucosal immune efficacy of engineered exosome-based vaccines.METHODS In vitro experiments:The murine dendritic cell line DC2.4 was transfected with a plasmid encoding the Lamp2b-RBD fusion protein.Real-time quantitative PCR and Western blotting were employed to assess Lamp2b-RBD expressions,flow cytometry was used to evaluate the proportion of Lamp2b-RBD-positive cells,and immunofluorescence staining was performed to determine their membrane localization.Exosomes were isolated via ultracentrifugation,and their morphology and particle size distribution were examined using transmission electron microscopy and nanoparticle tracking analysis.Western blotting was applied to confirm exosomal marker proteins[cluster of differentiation 9(CD9),CD63,ALG-2-interacting protein X(Alix),and Golgi marker GM130]and Lamp2b-RBD expression.In vivo experiments:① Female BALB/c mice were divided into the Lamp2b-RBD-Exo group and the lipid nanoparticle(LNP)group,and administered intratracheally for mucosal immunization.Pulmonary reten-tion was assessed by immunofluorescence staining.② Female BALB/c mice were divided into three groups:placebo group(PBS group),Lamp2b-RBD-Exo intratracheal administration group,and Lamp2b-RBD-Exo intramuscular injection group(im).Immunizations were performed on days 0 and 14,and on days 7 and 21.The titers of RBD-specific immunoglobulin G(IgG)in serum and RBD-specific IgA and IgG antibodies in bronchoalveolar lavage fluid were determined by enzyme-linked immunosor-bent assay(ELISA).RESULTS In vitro experiments:Lamp2b-RBD-positive cells accounted for 71.16％.Lamp2b-RBD mRNA levels were upregulated 1 979-fold compared with controls,with Lamp2b-RBD proteins localized on the cell membrane.Purified engineered exosomes displayed regular morphology,expressed CD9,CD63,and Alix but not GM130,had an average diameter of approximately 124 nm,and carried 3 009 pg of RBD protein per 1×109 exosomes.In vivo experiments:At 4 h after administra-tion,fluorescence signals were observed in the lung tissues of both the Lamp2b-RBD-Exo and LNPs groups.At 24 h,the fluorescence signal in the LNPs group shifted to the liver,while in the Lamp2b-RBD-Exo group,the fluorescence expanded from the trachea to the bronchioles and lung tissue,showing significantly better distribution and retention capacity than the LNPs group.Seven days after immuniza-tion,both the Lamp2b-RBD-Exo and Lamp2b-RBD-Exo(im)groups induced RBD-specific IgG antibody titers.At 21 days after immunization,Lamp2b-RBD-Exo elicited a higher level of RBD-specific immune response,with serum IgG titers reaching 1∶8 100 and bronchoalveolar lavage fluid(BALF)IgA titers reaching 1∶300.No RBD-specific IgA antibody titers were detected in the BALF of the Lamp2b-RBD-Exo(im)group.CONCLUSION Lamp2b-RBD modification enables efficient RBD protein loading and enhances pulmonary retention of engineered exosomes,thereby inducing potent antigen-specific mucosal immune responses.

Objective:To explore the clinical application value of a combined model based on the radiomics features of magnetic resonance imaging(MRI)and MRI signs in predicting recurrence after radical resection for hepatocellular carcinoma(HCC).Methods:A retrospective analysis was conducted on the imaging data of 100 patients with radical resection for HCC who admitted to Zibo 148 Hospital from May 2016 to May 2020.All patients underwent abdominal enhanced MRI examination before surgery,and they were followed up for at least 2 years after the surgery.They were randomly divided into training group(70 cases)and verification group(30 cases)as a ratio of 7:3.According to the postoperative follow-up results,the training group existed 12 cases of recurrence and 58 cases without recurrence,and the verification group existed 5 cases of recurrence and 25 cases without recurrence.The 3D-slicer software was used to extract radiomics features of preoperative MRI images of each HCC patient.The intra-group correlation coefficient(ICC)of the extracted imaging features of the observers was calculated.The maximum related minimum redundancy(mRMR)algorithm and LASSO regression were selected to analyze the established radiomics labels after dimensionality reduction and screening.Univariate and multivariate logistic regression analysis were used to screen the independent risk factors of predicting recurrence in MRI signs,and they were used respectively to construct radiomics models with the radiomics labels of plain scan,arterial phase,portal phase and hepatobiliary phase.The receiver operating characteristic(ROC)curve was used to assess the diagnostic efficacy of each radiomics model in predicting recurrence.Results:The ICC range of two physicians in selecting radiomics features from the MRI images of all patients were between 0.903 and 0.957,which consistency was favorable(ICC≥0.9).Compared with other predictive models,the highest area under curve(AUC)values of ROC curve of the radiomics model of plain scan of training group[0.951(95%CI:0.901-1.000)]and verification group[0.968(95%CI:0.917-1.000)]were respectively 0.951 and 0.968 in predicting recurrence after radical resection for liver cancer.Conclusion:The combined model that is constructed on the basis of MRI radiomics features has favorable predictive value for the recurrence of patients after radical resection for HCC.Among of them,the radiomics model of plain scan has a certain guiding role in the clinical implementation of personalized treatment plans under the absence of enhancement,and in underdeveloped areas.