The heart is an extremely sophisticated organ with nanoscale anisotropic structure, contractility and electro-conductivity; however, few studies have addressed the influence of cardiac anisotropy on cell transplantation for myocardial repair. Here, we hypothesized that a graft's anisotropy of myofiber orientation determines the mechano-electrical characteristics and the therapeutic efficacy. We developed aligned- and random-orientated nanofibrous electrospun patches (aEP and rEP, respectively) with or without seeding of cardiomyocytes (CMs) and endothelial cells (ECs) to test this hypothesis. Atomic force microscopy showed a better beating frequency and amplitude of CMs when cultured on aEP than that from cells cultured on rEP. For the in vivo test, a total of 66 rats were divided into six groups: sham, myocardial infarction (MI), MI + aEP, MI + rEP, MI + CM-EC/aEP and MI + CM-EC/rEP (n ≥ 10 for each group). Implantation of aEP or rEP provided mechanical support and thus retarded functional aggravation at 56 days after MI. Importantly, CM-EC/aEP implantation further improved therapeutic outcomes, while cardiac deterioration occurred on the CM-EC/rEP group. Similar results were shown by hemodynamic and infarct size examination. Another independent in vivo study was performed and electrocardiography and optical mapping demonstrated that there were more ectopic activities and defective electro-coupling after CM-EC/rEP implantation, which worsened cardiac functions. Together these results provide comprehensive functional characterizations and demonstrate the therapeutic efficacy of a nanopatterned anisotropic cardiac patch. Importantly, the study confirms the significance of cardiac anisotropy recapitulation in myocardial tissue engineering, which is valuable for the future development of translational nanomedicine.

Background: Autologous chimeric antigen receptor (CAR) T cell therapy is a promising therapeutic strategy for treating hematologic malignancies. A spectrum of serious complications caused by CAR-T cells has caught great attention. We developed a novel CAR against CD19 namely UWC19, consisting anti-CD19 single-chain variable fragment (scFv) hinged with 4-1BB and CD3z signaling domains. In this study, preclinical assessments of UWC19 were conducted to evaluate the safety and efficacy in vitro and in vivo. Methods: To evaluate the binding activity of UWC19 cells to CD19, we measured the saturation degree of CAR with human CD19 molecules using flow cytometry in vitro. The antitumor efficacy of UWC19 cells was determined by in vitro cytotoxicity assay against CD19 positive cells and in vivo using a xenograft mouse model. Cross tissue reactivity of UWC19 cells was examined by co-culturing with cell lines from difference human tissues. Tumorigenicity was determined by subcutaneously injecting UWC19 in immunodeficient mice. Persistence was analyzed using quantitative PCR. Results: We showed that UWC19 CAR T cells exerted highly specific binding affinity and cytotoxicity against CD19+ cells in vitro. In vivo, UWC19 CAR T cells are able to fully control disease progression in a Raji-xenografted immunodeficient mouse model. UWC19 exerted no obvious effects on the mean body mass and graft versus host disease were observed in surviving mice. We showed that UWC19 cells specifically recognized and eliminated CD19 positive cells, whereas CD19 negative cells were much less affected. No tumorigenicity of UWC19 in immunodeficient mice was observed. Conclusions: UWC19 treatment effectively eliminated CD19 positive tumor cells with favorable toxicity profile. The findings suggest encouraging clinical prospects for its use in patients with CD19 positive B cell malignancies. Our study presented an alternative evaluation strategy for CAR-T cell products.