Tissue-specific stem/progenitor cells are essential to mediate organogenesis and tissue homeostasis. In addition, these cells have attracted significant interest for their therapeutic potential. However, it remains challenging to expand most types of these cells in vitro. In this study we devised a screening strategy aimed at identifying growth factors and small molecules that can sustain self-renewal of mouse hepatoblasts. This approach began with a defined basal condition, on top of which collections of growth factors and bioactive small molecules were screened for maintaining self-renewal of primary hepatoblasts. The initially identified proteins and small molecules were then combined in the basal media for subsequent screening to identify additional molecules that can synergistically promote hepatoblast self-renewal. This strategy was performed iteratively to eventually define a small molecule and growth factor cocktail, including epidermal growth factor, glycogen synthase kinase 3 inhibitor, transforming growth factor b receptor inhibitor, lysophosphatidic acid, and sphingosine 1-phosphate, which was sufficient to sustain long-term self-renewal of the murine hepatoblasts under chemically defined conditions. These expanded hepatoblasts retain the ability to respond to liver developmental cues and produce functional hepatocytes and form bile duct-like structures. Conclusion: Our work established a chemically defined condition that allows long-term expansion of hepatoblasts, improved our understanding of hepatoblast self-renewal, and highlights the power of phenotypic screening to enable self-renewal of somatic stem/progenitor cells. (HEPATOLOGY 2015;61:337-347)

Somatic stem cells play crucial roles in organogenesis and tissue homeostasis and regeneration and may ultimately prove useful for cell therapy for a variety of degenerative diseases and injuries; however, isolation and expansion of most types of somatic stem cells from tissues are technically challenging. Human pluripotent stem cells are a renewable source for any adult cell types, including somatic stem cells. Generation of somatic stem cells from human pluripotent stem cells is a promising strategy to get these therapeutically valuable cells. Previously, we developed a chemically defined condition for mouse hepatoblast self-renewal through a reiterative screening strategy. In the present study, we efficiently generated hepatoblasts from human embryonic stem cells by a stepwise induction strategy. Importantly, these human embryonic stem cell-derived hepatoblasts can be captured and stably maintained using conditions previously established for mouse hepatoblast self-renewal, which includes basal media supplemented with insulin, transferrin, sodium selenite, epidermal growth factor, glycogen synthase kinase 3 inhibitor, transforming growth factor b receptor inhibitor, lysophosphatidic acid, and sphingosine 1-phosphate. The cells can stably retain hepatoblast phenotypes during prolonged culture and can differentiate into mature hepatocytes through in vitro provision of hepatocyte lineage developmental cues. After being embedded into three-dimensional Matrigel, these cells efficiently formed bile duct-like structures resembling native bile duct tissues. These human embryonic stem cell-derived hepatoblasts would be useful as a renewable source for cell therapy of liver diseases. STEM CELLS TRANSLATIONAL MEDICINE 2015;4:1275-1282 SIGNIFICANCE Somatic stem cells have been proposed as promising candidates for cell-based therapy; however, isolation of somatic stem cells from adult tissues is usually invasive and technically challenging. In the present study, hepatoblasts from human embryonic stem cells were efficiently generated. These human hepatoblasts were then stably captured and maintained by a growth factor and small molecule cocktail, which included epidermal growth factor, glycogen synthase kinase 3 inhibitor, transforming growth factor b receptor inhibitor, lysophosphatidic acid, and sphingosine 1-phosphate. These human embryonic stem cell-derived hepatoblasts would be useful as a renewable source for cell therapy of liver diseases.

Nonviral transposon piggyBac (PB) and lentiviral (LV) vectors have been used to deliver chimeric antigen receptor (CAR) to T cells. To understand the differences in the effects of PB and LV on CAR T-cell functions, a CAR targeting CD19 was cloned into PB and LV vectors, and the resulting pbCAR and lvCAR were delivered to T cells to generate CD19pbCAR and CD19lvCAR T cells. Both CD19CAR T-cell types were strongly cytotoxic and secreted high IFN-γ levels when incubated with Raji cells. TNF-α increased in CD19pbCAR T cells, whereas IL-10 increased in CD19lvCAR T cells. CD19pbCAR and CD19lvCAR T cells showed similar strong anti-tumor activity in Raji cell-induced mouse models, slightly reducing mouse weight while enhancing mouse survival. High, but not low or moderate, concentrations of CD19pbCAR T cells significantly inhibited Raji cell-induced tumor growth in vivo. These CD19pbCAR T cells were distributed mostly in mesenteric lymph nodes, bone marrow of the femur, spleen, kidneys, and lungs, specifically accumulating at CD19-rich sites and CD19-positive tumors, with CAR copy number being increased on day 7. These results indicate that pbCAR has its specific activities and functions in pbCAR T cells, making it a valuable tool for CAR T-cell immunotherapy.

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In transient high-speed scenes such as chemical explosions, magnetic compression, electric explosion, and laser-driven flyer, the target object can accelerate from 0 to tens of km/s in a few nanoseconds. The time-stretched photon Doppler velocimetry uses the time-stretched interferometry to downscale the frequency of the Doppler shift signal in the optical domain, which breaks through the bandwidth limitations of photoelectric detectors and electrical digital to analog converters. A quasi-continuous time-stretched photon Doppler velocimetry (QT-PDV) is proposed in this paper, for the measurement of microsecond high-speed movement events. On the principle of hardware optical path, the velocity signal of the target object is encoded on multiple stretched chirp pulses, avoiding sampling interruptions and trigger condition limitations; in the signal demodulation methods, the error compensation algorithm is used to compensate for the frequency shift signal, which reduces the system error caused by the displacement and increases the effective recording time. This paper adopts the high-power nanosecond laser to drive the metal film to produce a high-speed target, where beat frequency was downscaled to 2.2 GHz from 4.4 GHz.

Background: Malignant pleural/peritoneal mesothelioma (MPM) is a rare, aggressive cancer with poor prognosis and high mortality of 65%-70% for pleural and 30% for peritoneal MPM. Patients who fail the standard therapy often survive less than 1 year, so it is urgent to develop new effective therapies for MPM patients. Chimeric antigen receptor (CAR)-T cells have been applied in MPM, but the efficacy was still limited due to immunosuppressive tumor microenvironment (TME). To overcome these obstacles, we developed armored CAR-T cells with nanobody targeting mesothelin (MSLN) and IFN-γ-activated secretion of PD-1 nanobody in a non-viral transposon system, named as BZDS1901. Preclinical studies have demonstrated cytotoxicity of the BZDS1901 in NCI-H226 lung/mesothelioma xenograft mouse model. To verify the safety and efficacy of BZDS1901, we conducted a single-arm, open label, dose-escalating clinical trials (NCT04503980, 05089266, 03615313) in solid tumors. Methods: Eligible patients were those who failed prior standard therapies with MSLN expression (≥50%) and PD-L1 positive in tumor specimen and voluntarily signed the informed consent. After apheresis and lymphodepletion with cyclophosphamide and fludarabine. BZDS1901 was administered intravenously in dose cohorts (1 × 106-2 × 107/kg) and the second infusion was given if no disease progression. After infusion, safety was evaluated during 28 days by the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0, efficacy was assessed by RECIST 1.1 or mRECIST with CT scan. Blood CAR copies were measured by qPCR, PD-1 nanobodies and cytokines by Meso Scale Discovery method, and T cell subtypes by flow cytometry. Patients’ progression-free survival (PFS) and overall survival (OS) were measured from the day of infusion to progression or death. Results: From July 20, 2020 to December 31, 2022, 11 MPM patients were enrolled and completed the assessment, while most patients received two infusions. BZDS1901 was safe, demonstrated by 54% grade 3 and 15% grade adverse events (AEs) that were hematological side effects due to lymphodepletion and reversible with supportive care. No on-target, off-tumor toxicity and dose-limiting toxicity were observed. All patients showed expansion of CAR-T cells and increased PD-1 nanobodies in circulation. CAR-T Cmax (cp/μg) copies number was 20062, and continually detectable in blood over 4 months. PD-1 Cmax (pg/ml) was 82841, and continually detectable in blood for up to 9 months. IFN- γ and IL-6 also increased at day 4 or Day 7. All patients obtained objective tumor response, one with complete response, six with partial response, and four with stable disease. The total objective response rate was 63.64%. All enrolled patients are still alive, and mPFS and mOS are not reached. The longest PFS was up to 26 months. Median follow-up was four months. Conclusions: PD-1 nanobody secreted and MSLN targeting CAR-T cells have demonstrated promising efficacy on MPM patients. Besides CAR-T direct tumor killing activity, secreted PD-1 nanobodies may provide additional clinical benefit by invigorating CAR-T from PD-L1 inhibition, activating TILs and relieving local immunosuppression. Citation Format: Zhuqing Liu, Yong Xia, Linlin Li, Yan Sun, Zhicai Lin, Lijie Rong, Zhongzheng Zhu, Zongchang Song, Hui Xue, Jianchun Duan, Shujing Shen, Jing Wang, Linjie Lv, Yaping Yang, Xue Tan, Liping Han, Wei Zhao, Jie Wang, Wenfeng Xu, Weimin Zhu, Zhong Li, Xingya Li, Jinxing Lou, Qing Xu, Qijun Qian. Non-viral mesothelin-targeted CAR-T cells armored with IFNg-induced secretion of PD-1 nanobody in treatment of malignant mesothelioma in phase I clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT134.

For blade tip clearance measurement, the optical measurement method has the characteristics of high precision, anti-electromagnetic interference, and non-contact measurement. A dynamic and high-speed blade tip clearance measurement system based on time stretch dispersive Fourier transform with the optical comb is proposed and demonstrated. The dynamic experiments are designed to verify the accuracy of the system. The results show that the measuring speed is up to 17.6 MHz and the measurement errors are less than 1 μm under dynamic conditions. The experiments prove that the system has the advantages of high measurement accuracy, high speed, and good repeatability. It can provide a new tool for engine health monitoring.

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