A mechanical HSA biosensor based on multi-field-coupling-mediated magnetic sensitization strategy.

The conventional mechanical biosensor based on stress and electrical conversion can be an effective method to detect key human biomarkers for clinical diagnosis and early disease prevention. However, the applications of this type of biosensor are greatly limited due to their unsatisfactory sensitivity. In this work, a magnetic-sensitized (MS) mechanical biosensor based on multi-field coupling was developed for higher sensitivity, giving access to detect human serum albumin (HSA). Via introducing secondary magnetic antibodies labeled with magnetized Fe2O3 nanoparticles to the stress and electrical conversion element of the MS-biosensor, the multi-field coupling was realized based on stress, electricity, and magnetism. Under the action of the magnetic field, the magnetic force of the secondary magnetic antibody and the stress of antigen-antibody binding jointly drove and enhanced the deformation of the MS-biosensor, amplifying the electrical signal, and realizing magnetic sensitization. The HSA was detected by the MS-biosensor at a range of 0-80 µg/mL with a limit of detection (LOD) of 0.14 µg/mL, demonstrating the high performance of the MS-biosensor. Moreover, the MS-biosensor showed high selectivity, specificity, and stability, indicating that the magnetic sensitization strategy of the MS-biosensor was significant for the clinical application of mechanical biosensors.

Adenovirus vaccine therapy with CD137L promotes CD8+ DCs-mediated multifunctional CD8+ T cell immunity and elicits potent anti-tumor activity.

Renal carcinoma progresses aggressively in patients with metastatic disease while curative strategies are limited. Here, we constructed a recombinant non-replicating adenovirus (Ad) vaccine encoding an immune activator, CD137L, and a tumor antigen, CAIX, for treating renal carcinoma. In a subcutaneous tumor model, tumor growth was significantly suppressed in the Ad-CD137L/CAIX vaccine group compared with the single vaccine group. The induction and maturity of CD11C+ and CD8+CD11C+ dendritic cell (DC) subsets were promoted in Ad-CD137L/CAIX co-immunized mice. Furthermore, the Ad-CD137L/CAIX vaccine elicited stronger tumor-specific multifunctional CD8+ T cell immune responses as demonstrated by increased proliferation and cytolytic function of CD8+ T cells. Notably, depletion of CD8+ T cells greatly compromised the effective protection provided by Ad-CD137L/CAIX vaccine, suggesting an irreplaceable role of CD8+ T cells for the immunopotency of the vaccine. In both lung metastatic and orthotopic models, Ad-CD137L/CAIX vaccine treatment significantly decreased tumor metastasis and progression and increased the induction of tumor-specific multifunctional CD8+ T cells, in contrast to treatment with the Ad-CAIX vaccine alone. The Ad-CD137L/CAIX vaccine also augmented the tumor-specific multifunctional CD8+ T cell immune response in both orthotopic and metastatic models. These results indicated that Ad-CD137L/CAIX vaccine elicited a potent anti-tumor activity by inducing CD8+DC-mediated multifunctional CD8+ T cell immune responses. The potential strategy of CD137L-based vaccine might be served as a novel treatment for renal carcinoma or other malignant tumors.

Magneto-Mechanical Coupling Study of Magnetorheological Elastomer Thin Films for Sensitivity Enhancement.

Magnetorheological elastomer thin films (MREFs) exhibit remarkable deformability and an adjustable modulus under magnetic fields, rendering them promising in fields such as robotics, flexible sensors, and biomedical engineering. Here, we fabricated MREF by introducing magnetostrictive particles (MSPs) and evaluated the magneto-mechanical coupling effect on the enhancement of sensitivity. The saturation magnetization (Ms) in a parallel anisotropic TbDyFe-PDMS MREF was 5.8 emu/g, and the initial tensile modulus was 55% greater than that of an Iso MREF. We propose a nonlinear magnetorheological formula on the magnetostriction effect, incorporating magnetic dipole interactions and the nonlinear prestress of magnetic particles. This formula highlights the complex nonlinear relationship between the external magnetic field (H) and the key parameters that affect the enhanced MR effect of MSPs-MREF, such as saturation magnetization, remanence (Mr), magnetostriction constant (λs) and stress deviator in ferromagnetic particles (Sed) in the magnetic chain structure. Furthermore, we validate the influence of the key parameters of the rectified magnetorheological formula on a nonlinear magneto-mechanical behavior of MSPs-MREF in PDMS-based MSPs-MREF models by using finite-element simulations. Finally, we developed a biosensor based on MSPs-MREF to detect human serum albumin at low concentrations in human urine samples. There is a 4-fold increase in sensitivity, a lower detection of limit (0.442 µg/mL), and a faster response time (15 min) than traditional biosensors, which in the future might provide an effective way of detecting biomolecules of low concentrations.

Multilayer Heterogeneous Membrane Biosensor Based on Multiphysical Field Coupling for Human Serum Albumin Detection.

A factor closely associated with renal disease status in clinical diagnosis is abnormal human serum albumin (HSA) concentration levels in human body fluids urine, serum, etc. The surface stress biosensor was developed as a new type of biosensor to detect protein molecule concentration and has a wide range of clinical applications. However, further sensitivity improvement is required to achieve higher detection performance. Herein, MXene/PDMS/Fe3O4/PDMS of the multilayer heterogeneous membrane biosensor (MHBios) based on the coupling of the magnetic field, electric field, and surface stress field was successfully developed to achieve high sensitivity HSA detection through magnetic sensitization. The modified antibody specifically binds to HSA at the AuNP layer, allowing the biosensor to convert the surface stress caused by PDMS film deformation into an electrical signal. When the biosensor was exposed to a uniform magnetic field, the conductive path of the conductive layer was reshaped further as the magnetic force amplified the deformation of the PDMS film, enhancing the conversion of biological signals to electrical signals. The results exhibited that the detection limit (LOD) of the MHBios was 78 ng/mL when HSA concentration was 0-50 µg/mL, which was markedly lower than the minimum diagnostic limit of microalbuminuria. Furthermore, the MHBios detected HSA in actual samples, confirming the potential for early disease screening.

A mechanical biosensor based on membrane-mediated magneto-stress-electric coupled sensitization for human serum albumin detection.

Recently, mechanical biosensors have attracted more attention on single molecule detection due to its high accuracy, low cost, and convenience. However, the sensitivity of the mechanical biosensors restricted their clinical application. Herein, a mechanical biosensor based on membrane-mediated magneto-stress-electric coupled sensitization (MSEC-MMB) was developed to enhance performance. Through introducing Fe3O4 nanoparticles (MNPs) to traditional stress-electric biosensors and applying a magnetic field, a magneto-stress-electric coupled biosensing system was constructed. The sensitivity of the MSEC-MMB was improved via enhancing the deformation of the mechanical membrane, which was demonstrated by detecting HSA. The optimal limit of detection (LOD) was 24 pg mL-1 under a magnetic field of 50 mT. The LOD was significantly 1 order of magnitude lower than that without the magnetic field. Besides, the MSEC-MMB showed a high specificity, selectivity, and stability. The clinical proteinuria samples were accurately detected, suggesting a good practicability of the MSEC-MMB. All these results proved the high sensitivity and practicality of the MSEC-MMB and provide a platform for early nephropathy diagnosis.

Dual-targeting vaccine of FGL1/CAIX exhibits potent anti-tumor activity by activating DC-mediated multi-functional CD8 T cell immunity.

Tumor DNA vaccine as an effective therapeutic approach can induce systemic immunity against malignant tumors, but its therapeutic effect is still not satisfactory in advanced renal cancer. Herein, a novel DNA vaccine containing dual antigens of fibrinogen-like protein 1 (FGL1) and carbonic anhydrase IX (CAIX) was developed and intramuscularly delivered by PLGA/PEI nanoparticles for renal cancer therapy. Compared with PLGA/PEI-pCAIX immunization, PLGA/PEI-pFGL1/pCAIX co-immunization significantly inhibited the subcutaneous tumor growth and promoted the differentiation and maturation of CD11c+ DCs and CD11c+CD11b+ DCs subset. Likewise, the increased capabilities of CD8 T cell proliferation, CTL responses, and multi-functional CD8+ T cell immune responses were observed in PLGA/PEI-pFGL1/pCAIX vaccine group. Interestingly, depletion of CD8+ T cells by using CD8 mAb resulted in a loss of anti-tumor function of PLGA/PEI-pFGL1/pCAIX vaccine, suggesting that the anti-tumor activity of the vaccine was dependent on CD8+ T cell immune responses. Furthermore, PLGA/PEI-pFGL1/pCAIX co-immunization also suppressed the lung metastasis of tumor mice by enhancing the multi-functional CD8+ T cell responses. Therefore, these results indicate that PLGA/PEI-pFGL1/pCAIX vaccine could provide an effective protective effect for renal cancer by enhanced DC-mediated multi-functional CD8+ T cell immune responses. This vaccine strategy offers a potential approach for solid or metastatic tumor treatment.

[Correlation of the CTD structural domain of hepatitis B virus core protein with the encapsulation effect of indocyanine green].

Hepatitis B virus core protein (HBc) has become a hot spot in drug carrier protein research due to its natural particle self-assembly ability and ease of modification. The truncation of the C-terminal polyarginine domain (CTD, aa 151-183) of HBc does not affect the self-assembly of the particles. However, it does affect the internal and external charges of the particles, which may subsequently affect drug encapsulation. Thus, the truncated C-terminal polyarginine domain (CTD) of HBc and the inserted RGD peptide were selected to construct and express three HBc variants (RH) encapsulated with ICG (RH/ICG) with different C-terminal lengths to compare the stability and drug activity of their nanoformulations. RH160/ICG was found to have a great advantages in encapsulation efficiency and biological imaging. Compared with other HBc variants, RH160/ICG significantly improved encapsulation efficiency, up to 32.77%±1.23%. Cytotoxicity and hemolysis assays further demonstrated the good biocompatibility of RH160/ICG. Cell uptake and in vivo imaging experiments in mice showed that RH160/ICG could efficiently deliver ICG in tumor cells and tumor sites with good imaging effect. This research provides a new direction for further expanding the diagnosis and treatment application of ICG and development of HBc-based nanoparticle drug carrier platform.

Co-immunizing with PD-L1 induces CD8+ DCs-mediated anti-tumor immunity in multiple myeloma.

Tumor therapeutic vaccines have faced a challenge for effective protection against malignant tumors by inducing tumor-specific CD8+ T cell responses. Here, we designed a DNA vaccine containing a tumor-specific antigen of Dickkopf-1 (DKK-1) and an immune checkpoint of programmed death ligand 1 (PD-L1) delivered by PLGA/PEI nanoparticle-mediated delivery system for multiple myeloma therapy. Murine subcutaneous tumor model established with human DKK1 (hDKK-1)-SP2/0 cells were intramuscularly immunized with PLGA/PEI-pPD-L1/pDDK-1 vaccine and equal amount of control 3 times at 10 day-intervals. Compared with PLGA/PEI-pDKK1 immunization group, PLGA/PEI-pPD-L1/pDKK-1 co-immunization enhanced the induction and mature of CD11c+ DCs and CD8+CD11c+ DCs, and promoted antigen-specific Th1 responses and cytotoxic T lymphocyte (CTL) responses. The reduced tumor volume and weight as well as increased tumor inhibition rate were observed in PLGA/PEI-pPD-L1/pDKK-1 vaccine co-immunization group, indicated that the vaccine could effectively inhibit the tumor growth of multiple myeloma. The anti-tumor activity of PLGA/PEI-pPD-L1/pDKK-1 vaccine was abrogated by CD8 cell depletion accompanied with the reduced percentages of CD8+CD11c+ DCs and CD8+ T cells in the spleen and TILs. These results indicated that the anti-tumor efficacy of PLGA/PEI-pPD-L1/pDKK-1 vaccine was required for CD8+CD11c+ DCs-mediated CD8+ T cell immunity responses. This vaccine strategy may represent a potential and promising approach for hematological malignancy treatment.

MiRNA-Sequence Indicates That Mesenchymal Stem Cells and Exosomes Have Similar Mechanism to Enhance Cardiac Repair.

Mesenchymal stem cells (MSCs) repair infarcted heart through paracrine mechanism. We sought to compare the effectiveness of MSCs and MSC-derived exosomes (MSC-Exo) in repairing infarcted hearts and to identify how MSC-Exo mediated cardiac repair is regulated. In a rat myocardial infarction model, we found that MSC-Exo inhibited cardiac fibrosis, inflammation, and improved cardiac function. The beneficial effects of MSC-Exo were significantly superior compared to that of MSCs. To explore the potential mechanisms underlying MSC-Exo's effects, we performed several in vitro experiments and miRNA-sequence analysis. MSC-Exo stimulated cardiomyocyte H9C2 cell proliferation, inhibited apoptosis induced by H2O2, and inhibited TGF-ß induced transformation of fibroblast cell into myofibroblast. Importantly, novel miRNA sequencing results indicated that MSC-Exo and MSCs have similar miRNA expression profile, which could be one of the reasons that MSC-Exo can replace MSCs for cardiac repair. In addition, the expression of several miRNAs from MSC-Exo was significantly different from that of MSCs, which may explain why MSC-Exo has better therapeutic effect than MSCs. In conclusion, this study demonstrates that MSC-Exo could be used alone to promote cardiac repair and are superior to MSCs in repairing injured myocardium.

Dynamic expression of microRNAs in M2b polarized macrophages associated with systemic lupus erythematosus.

Macrophage polarization contributes to the initiation and perpetuation of systemic lupus erythematosus (SLE). Our previous study demonstrated that M2b polarized macrophages induced by activated lymphocyte-derived DNA (ALD-DNA) have a crucial function in the initiation and progress of SLE disease. Accumulated data suggest that microRNAs (miRNAs) serve as critical regulators to control macrophage polarization. To investigate miRNA regulation during macrophage M2b polarization of SLE, miRNA microarrays of murine bone marrow derived macrophages (BMDMs) were performed following stimulation with ALD-DNA for 6 and 36 h. Over 11% of the 1111 analyzed miRNAs appeared differentially expressed during ALD-DNA triggered macrophage M2b polarization. Cluster analysis revealed certain patterns in miRNA expression that are closely linked to ALD-DNA induced macrophage M2b polarization. Analysis of the network structure showed that the predicted functions of the differentially regulated miRNAs at 6h are significantly associated with inflammatory response and disease. Differentially regulated miRNAs identified at 36 h were determined to be significantly related to cell proliferation by biological network analysis. In this study, dynamic miRNA expression patterns and network analysis are described for the first time during ALD-DNA induced macrophage M2b polarization. The data not only provide a better understanding of miRNA-mediated macrophage polarization but also demonstrate the future therapeutic potential of targeting miRNAs in SLE patients.