Facile and Rapid Microcontact Printing of Additive-Free Polydimethylsiloxane for Biological Patterning Diversity.

The development and application of micropatterning technology play a promising role in the manipulation of biological substances and the exploration of life sciences at the microscale. However, the universally adaptable micropatterning method with user-friendly properties for acceptance in routine laboratories remains scarce. Herein, a green, facile, and rapid microcontact printing method is reported for upgrading popularization and diversification of biological patterning. The three-step printing can achieve high simplicity and fidelity of additive-free polydimethylsiloxane (PDMS) micropatterning and chip fabrication within 8 min as well as keep their high stability and diversity. A detailed experimental report is provided to support the advanced microcontact printing method. Furthermore, the applications of easy-to-operate PDMS-patterned chips are extensively validated to complete microdroplet array assembly with spatial control, cell pattern formation with high efficiency and geometry customization, and microtissue assembly and biomimetic tumor construction on a large scale. This straightforward method promotes diverse micropatternings with minimal time, effort, and expertise and maximal biocompatibility, which might broaden its applications in interdisciplinary scientific communities. This work also offers an insight into the establishment of popularized and market-oriented microtools for biomedical purposes such as biosensing, organs on a chip, cancer research, and bioscreening.

Butylphthalide protects against ischemia-reperfusion injury in rats via reducing neuron ferroptosis and oxidative stress.

Local ischemia in the cerebra leads to vascular injury and necrosis. Ferroptosis is involved in the pathophysiological process of many diseases and widely exists when ischemia-reperfusion injury occurs in many organs. The aim of this study was to evaluate the effect of Butylphthalide (NBP) on middle cerebral artery occlusion (MCAO) rats model-caused neuron injury. Sprague Dawley Rats were randomly allocated to receive sham and MCAO operation. NBP low-dose (40 mg/kg b.w), and high-dose (80 mg/kg b.w) were administrated in MACO rats. Results showed NBP improves infarct volume, attenuates neuronal apoptosis in the brain tissue of MCAO rats. The tumor necrosis factor (TNF-α), IL-6, and malondialdehyde (MDA) levels decreased after NBP administration, while the activity of superoxide dismutase (SOD) and the ratio of GSH/GSSG in MACO rats increased. MACO caused non-heme iron accumulation in the brain tissue and Perl's staining confirmed NBP attenuates ferroptosis in MACO rats. The protein expressions of SCL7A11 and glutathione peroxidase 4 (GPX4) decreased following MCAO, and NBP treatment subsequently increased the expression of SCL7A11 and GPX4. In vitro analysis in cortical neuron cells indicated that the GPX4 inhibitor reverses the inhibition of ferroptosis by NBP, which suggested that the SCL7A11/GPX4 pathway majorly contributed to the NBP ferroptosis protection effect.

Facile construction of a 3D tumor model with multiple biomimetic characteristics using a micropatterned chip for large-scale chemotherapy investigation.

The establishment and application of biomimetic preclinical tumor models for generalizable and high-throughput antitumor screening play a promising role in drug discovery and cancer therapeutics. Herein, a facile and robust microengineering-assisted methodology for highly biomimetic three-dimensional (3D) tumor construction for dynamic and large-scale antitumor investigation is developed using micropatterned array chips. The high fidelity, simplicity, and stability of chip fabrication are guaranteed by improved polydimethylsiloxane (PDMS) microcontact printing. The employment of a PDMS-micropatterned chip permits microscale, simple, biocompatible, and reproducible cell localization with quantity uniformity and 3D tumor array formation with geometric homogeneity. Array-like 3D tumor models possessing complex multilayer cell arrangements, diverse phenotypic gradients, and biochemical gradients were prepared based on the use of easy-to-operate chips. The applicability of the established biomimetic models in temporal and massive investigations of tumor responses to antitumor chemotherapy is also verified experimentally. The results support the importance of the dimensional geometry and biomimetic degree of 3D tumors when conducting antitumor screening to explore drug susceptibility and resistance. This work provides a facile and reliable strategy to perform highly biomimetic tumor manipulation and analysis, which holds great potential for applications in oncology, pharmacology, precision medicine, and tissue microengineering.

Combinatorial Drug Screening Based on Massive 3D Tumor Cultures Using Micropatterned Array Chips.

The establishment and application of a generalizable three-dimensional (3D) tumor device for high-throughput screening plays an important role in drug discovery and cancer therapeutics. In this study, we introduce a facile microplatform for considerable 3D tumor generation and combinatorial drug screening evaluation. High fidelity of chip fabrication was achieved depending on the simple and well-improved microcontact printing. We demonstrated the high stability and repeatability of the established tumor-on-a-chip system for controllable and massive production of 3D tumors with high size uniformity. Importantly, we accomplished the screening-like chemotherapy investigation involving individual and combinatorial drugs and validated the high accessibility and applicability of the system in 3D tumor-based manipulation and analysis on a large scale. This achievement in tumor-on-a-chip has potential applications in plenty of biomedical fields such as tumor biology, pharmacology, and tissue microengineering. It offers an insight into the development of the popularized microplatform with easy-to-fabricate and easy-to-operate properties for cancer exploration and therapy.

Parallel and large-scale antitumor investigation using stable chemical gradient and heterotypic three-dimensional tumor coculture in a multi-layered microfluidic device.

BACKGROUND: Cancer has been responsible for a large number of human deaths in the 21st century. Establishing a controllable, biomimetic, and large-scale analytical platform to investigate the tumor-associated pathophysiological and preclinical events, such as oncogenesis and chemotherapy, is necessary. METHODS AND RESULTS: This study presents antitumor investigation in a parallel, large-scale, and tissue-mimicking manner based on well-constructed chemical gradients and heterotypic three-dimensional (3D) tumor cocultures using a multifunction-integrated device. The integrated microfluidic device was engineered to produce a controllable and steady chemical gradient by manipulative optimization. Array-like and size-homogeneous production of heterotypic 3D tumor cocultures with in vivo-like features, including similar tumor-stromal composition and functional phenotypic gradients of metabolic activity and viability, was successfully established. Furthermore, temporal, parallel, and high-throughput analyses of tumor behaviors in different antitumor stimulations were performed in a device based on the integrated operations involving gradient generation and coculture. CONCLUSION: This achievement holds great potential for applications in the establishment of multifunctional tumor platforms to perform tissue-biomimetic neoplastic research and therapy assessment in the fields of oncology, bioengineering, and drug discovery.

An integrated microfluidic 3D tumor system for parallel and high-throughput chemotherapy evaluation.

The development of a microplatform with multifunctional integration allowing the dynamic and high-throughput exploration of three-dimensional (3D) cultures is promising for biomedical research. Here, we introduce an integrated microfluidic 3D tumor system with pneumatic manipulation and chemical gradient generation to investigate anticancer therapy in a parallel, controllable, dynamic, and high-throughput manner. The stability of the microfluidic system to realize precise and long-term chemical gradient production was developed. Serial manipulations including active cell trapping, array-like tumor self-assembly and formation, reliable gradient generation, parallel multi-concentration drug stimulation, and real-time tumor analysis were achieved in a single microfluidic device. The microfluidic platform was demonstrated to be stable for high-throughput cell trapping and 3D tumor formation with uniform quantities. On-chip analysis of phenotypic tumor responses to diverse chemotherapies with different concentrations can be conducted in this device. The microfluidic advancement holds great potential for applications in the development of high-performance and multi-functional biomimetic tumor systems and in the fields of cancer research and pharmaceutical development.

Large-Scale Antitumor Screening Based on Heterotypic 3D Tumors Using an Integrated Microfluidic Platform.

Chemotherapy screening plays a crucial role in cancer drug discovery and clinical medicine. Although conventional methods have contributed greatly to macromanipulation of cell populations, profounder insights related to the tumor microenvironment require approaches for completing integrated cell-3D tumor micromanipulation, massive tumor simulation and production, and dynamic and high-throughput tumor analysis. In this study, we introduced an integrated microfluidic platform with multiparallel components for heterotypic 3D tumor reconstruction and antitumor screening. Sequential microfluidic manipulations including sample loading, precise localization, 3D tumor formation, chemical stimulation, on-chip analysis, and tumor recovery for off-chip assessment were permitted and experimentally confirmed in the device on the basis of facile and efficient pneumatic control. Heterotypic 3D tumors with tissue-biomimetic phenotypes can be produced in massive and size-uniform manners. Notably, we accomplished a screening-like chemotherapy assessment involving different heterotypic 3D tumors and antitumor drugs and demonstrated the versatility of the platform in large-scale tumor manipulation and analysis. This advancement in microfluidics has potential applications in the fields of oncology, pharmacology, and tissue engineering and provides insight into the construction of high-performance microsystems for drug development and cancer research.

Antitumor activity of cobrotoxin in human lung adenocarcinoma A549 cells and following transplantation in nude mice.

The aim of the present study was to investigate cobra neurotoxin (cobrotoxin) activity in A549 cell lines transplanted into nude mice, and to explore its molecular mechanism. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to detect the growth inhibition rate of cobrotoxin in human lung A549 adenocarcinoma cells and HFL1 lung fibroblasts. Cell colony formation assays were performed to determine the effect of cobrotoxin on A549 cell colony formation, and transmission electron microscopy was used to detect cobrotoxin autophagy. In addition, western blot analysis was performed to determine the effect of 3-methyl adenine (3-MA) activity on the inhibition of autophagy, SB203580 inhibition of the p38-mitogen-activated protein kinase (MAPK) pathway, and Beclin 1, LC3, p62, p38 and phosphorylated (p)-p38 protein expression. Nude mice were injected with human lung A549 cells, and intervention and control groups were compared with regard to tumor suppression. The MTT assay revealed that various concentrations of cobrotoxin inhibited growth of A549 cells, but not HFL1 cells. A549 cell colony formation decreased and autophagosome activity was significantly increased compared with the controls. Following 3-MA administration, SB203580 autophagosome activity decreased, and following cobrotoxin administration, Beclin 1, p-p38, and LC3-II protein expression significantly increased, whereas p62 expression significantly decreased. Following 3-MA inhibition of autophagy, Beclin 1, LC3-II and p62 expression increased. Furthermore, following SB203580 inhibition of the p38-MAPK pathway, Beclin 1, p-p38, LC3-II and p62 protein expression increased. Cobrotoxin exhibited inhibitory activity on the human lung cancer A549 cells transplanted into the nude mice, suppressing the tumor growth rate by 43.4% (cobrotoxin 40 µg/kg group). However, following the addition of 3-MA (10 mmol/kg) and SB203580 (5 mg/kg), the suppression of the tumor growth rate decreased significantly. Cobrotoxin inhibits the growth of human lung cancer A549 cells in vitro and A549 cells transplanted into nude mice. Furthermore, the induction of autophagy may be associated with the activation of the p38-MAPK pathway.