Oxygen plays a crucial role in microbial growth and metabolism. However, the detailed bacterial responses and regulatory mechanisms toward the change of oxygen are still not completely understood partly due to the lack of real-time measurement and control of dissolved oxygen (DO). Here, we present a novel platform for spatiotemporal and real-time controls of oxygen concentrations by a simple microfluidic design in bacteria suspension culture on chip. The DO concentrations are precisely controlled or flexibly tuned in bioreactor arrays in nanoliter scale. Multiple bioreactor groups with diverse DO control strategies are integrated on a single chip. With our platform, adequate oxygen existed in the microfluidic culture channels and may be the critical factor for the fast growth during bacteria suspension culture. Notably, we extend our platform to mimic the DO oscillation environment and monitor the growth of bulk and single bacterium for many generations. This microfluidic platform exhibits the unique capability of spatiotemporal gas control and detection for microbial suspension culture in nanoliter scale, which can be applied for screening, studying, and culturing the industrial or niche-specific environmental microbiome, at bulk, single cell, or consortia level, responding to oxygen or other gas environment, such as carbon dioxide, ammonia, etc.

The trans-cleavage property of CRISPR-Cas12a system makes it an excellent tool for disease diagnosis. Nevertheless, most methods based on CRISPR-Cas system still require pre-amplification of the target to achieve the desired detection sensitivity. Here we generate Framework-Hotspot reporters (FHRs) with different local densities to investigate their effect on trans-cleavage activity of Cas12a. We find that the cleavage efficiency increases and the cleavage rate accelerates with increasing reporter density. We further construct a modular sensing platform with CRISPR-Cas12a-based target recognition and FHR-based signal transduction. Encouragingly, this modular platform enables sensitive (100 fM) and rapid (<15 min) detection of pathogen nucleic acids without pre-amplification, as well as detection of tumor protein markers in clinical samples. The design provides a facile strategy for enhanced trans cleavage of Cas12a, which accelerates and broadens its applications in biosensing.

Point-of-care testing (POCT) can be the method of choice for detecting infectious pathogens; these pathogens are responsible for not only infectious diseases such as COVID-19, but also for certain types of cancers. For example, infections by human papillomavirus (HPV) or Helicobacter pylori (H. pylori) are the main cause of cervical and stomach cancers, respectively. COVID-19 and many cancers are treatable with early diagnoses using POCT. A variety of nucleic acid testing have been developed for use in resource-limited environments. However, questions like unintegrated nucleic acid extraction, open detection systems increase the risk of cross-contamination, and dependence on expensive equipment and alternating current (AC) power supply, significantly limit the application of POCT, especially for on-site testing. In this paper, a simple portable platform is reported capable of rapid sample-to-answer testing within 30 min based on recombinase polymerase amplification (RPA) at a lower temperature, to detect SARS-CoV-2 virus and H. pylori bacteria with a limit of detection as low as 4 × 102 copies mL-1 . The platform used a battery-powered portable reader for on-chip one-pot amplification and fluorescence detection, and can test for multiple (up to four) infectious pathogens simultaneously. This platform can provide an alternative method for fast and reliable on-site diagnostic testing.

Renal cell carcinoma (RCC) is the most common type of kidney cancer. Owing to the high morbidity rate of RCC, there is an urgent need for intensive research on robust materials to diagnose and treat RCC. Nanomaterials have been developed largely in the last three decades because of their numerous advantages, such as high specific surface area, simple surface functionalization, rapid onset of therapeutic action, superior biological activity, and other unique physical–chemical characteristics. Herein, first, various types of nanomaterials used in RCC treatment are introduced, including inorganic nanomaterials, lipid nanomaterials, synthetic polymer nanomaterials, and natural nanomaterials. Second, the different diagnosis and therapeutic mechanisms of nanomaterials in the kidneys are reviewed and these advantages of nanomaterials are highlighted. Furthermore, nanomaterials are investigated for the preclinical and clinical detection and treatment of RCC. Finally, the challenges and outlook of various nanomaterials for RCC diagnostic and treatment are discussed.

目的:构建一种快速简单的高危型人乳头瘤病毒(high-risk human papillomavirus,hr-HPV)现场诊断方法,以期加强对hr-HPV感染的监测及其相关癌症的预防和早期筛查.方法:以重组酶聚合酶扩增(recombinase polymerase amplifcation,RPA)反应为基础,建立一种快速且准确的可视化hr-HPV检测方法.采用纸基富集法提取样本中的HPV-DNA,构建恒温孵育与结果读取一体化的充电式便携阅读器,并且使用hr-HPV模拟病毒样本评估本方法的性能.结果:该方法实现了30 min内的样本进-结果出的免仪器检测,并且能够输出可视化结果.对hr-HPV模拟病毒样本的检测灵敏度可达104 copies/mL,并且稳定性和特异度均表现良好.结论:该方法使用简单且性能优越,可以根据需要广泛部署于靠近患者的护理点以及社区医院、诊所和药房等基层卫生服务设施,有助于加强对hr-HPV感染的监测及其相关癌症的预防和早期筛查.

Immune and targeted therapy are becoming the first-line treatment for renal cell carcinoma (RCC). However, therapeutic outcomes are limited due to the low efficiency and side effect. Here, it is found that helicenes are able to exhibit an anticancer capability through changing the molecular structure from planar to nonplanar. Furthermore, the cytotoxicity in vitro and cancer inhibition ability of nonplanar helicenes increase with its aromatic rings' number. It is further demonstrated that benzo[4]helicenium shows the specific killing efficiency against the RCC cancer as compared to normal kidney cells. This is majorly originated from a more selective damage of benzo[4]helicenium for mitochondria and DNA in RCC cancer cells, not the normal kidney. The selective killing ability of benzo[4]helicenium makes it have potential to be used as a targeted drug for the precise treatment of RCC.

Front Cover In article number 2100770, Dai, Qiu, Liu and co-workers demonstrate the water-soluble benzo[4]helicenium has selective killing effects of renal cell carcinoma through inducing DNA damage. Compared with normal cells, it can more easily enter the tumor cells and further affect the biological functions of DNA because of the rapid mitosis. Benzo[4]helicenium is expected to be a novel drug for the precise therapy of renal cell carcinoma.