Multi‐omics usually refers to the crossover application of multiple high‐throughput screening technologies represented by genomics, transcriptomics, single‐cell transcriptomics, proteomics and metabolomics, spatial transcriptomics, and so on, which play a great role in promoting the study of human diseases. Most of the current reviews focus on describing the development of multi‐omics technologies, data integration, and application to a particular disease; however, few of them provide a comprehensive and systematic introduction of multi‐omics. This review outlines the existing technical categories of multi‐omics, cautions for experimental design, focuses on the integrated analysis methods of multi‐omics, especially the approach of machine learning and deep learning in multi‐omics data integration and the corresponding tools, and the application of multi‐omics in medical researches (e.g., cancer, neurodegenerative diseases, aging, and drug target discovery) as well as the corresponding open‐source analysis tools and databases, and finally, discusses the challenges and future directions of multi‐omics integration and application in precision medicine. With the development of high‐throughput technologies and data integration algorithms, as important directions of multi‐omics for future disease research, single‐cell multi‐omics and spatial multi‐omics also provided a detailed introduction. This review will provide important guidance for researchers, especially who are just entering into multi‐omics medical research.

This tutorial review summarizes the common performances, featured properties and various state-of-the-art biomedical applications of liquid metals.

Depression is a heterogeneous disorder, with the exact neuronal mechanisms causing the disease yet to be discovered. Recent work suggests it is accompanied by neuro-inflammation, characterized, in particular, by microglial activation. However, microglial activation and its involvement in neuro-inflammation and stress-related depressive disorders are far from understood. We utilized multiple detection methods to detect the neuro-inflammation in the hippocampus of rats after exposure to chronic mild stress (CMS). Male Sprague Dawley (SD) rats were subjected to chronic mild stressors for 12 weeks. Microglial activation and hippocampal neuro-inflammation were detected by using a combinatory approach of in vivo [18F] DPA-714 positron emission computed tomography (PET) imaging, ionized calcium-binding adapter molecule 1 and translocator protein (TSPO) immunohistochemistry, and detection of NOD-like receptor protein 3 (NLRP3) inflammasome and some inflammatory mediators. Then, the rats were treated with minocycline during the last 4 weeks to observe its effect on hippocampal neuro-inflammation and depressive-like behavior induced by chronic mild stress. The results show that 12 weeks of chronic mild stress induced remarkable depressive- and anxiety-like behavior, simultaneously causing hippocampal microglial activation detected by PET, immunofluorescence staining, and western blotting. Likewise, activation of NLRP3 inflammasome and upregulation of inflammatory mediators, such as interleukin-1β (IL-1β), IL-6, and IL-18, were also observed in the hippocampus after exposure to chronic stress. Interestingly, the anti-inflammatory mediators, such as IL-4 and IL-10, were also increased in the hippocampus following chronic mild stress, which may hint that chronic stress activates different types of microglia, which produce pro-inflammatory cytokines or anti-inflammatory cytokines. Furthermore, chronic minocycline treatment alleviated the depressive-like behavior induced by chronic stress and significantly inhibited microglial activation. Similarly, the activation of NLRP3 inflammasome and the increase of inflammatory mediators were not exhibited or significantly less marked in the minocycline treatment group. These results together indicate that microglial activation mediates the chronic mild stress-induced depressive- and anxiety-like behavior and hippocampal neuro-inflammation.

Developing multifunctional and easily prepared nanoplatforms with integrated different modalities is highly challenging for molecular imaging. Here, we report the successful transfer of an important molecular target, melanin, into a novel multimodality imaging nanoplatform. Melanin is abundantly expressed in melanotic melanomas and thus has been actively studied as a target for melanoma imaging. In our work, the multifunctional biopolymer nanoplatform based on ultrasmall (<10 nm) water-soluble melanin nanoparticle (MNP) was developed and showed unique photoacoustic property and natural binding ability with metal ions (for example, ⁶⁴Cu²⁺, Fe³⁺). Therefore, MNP can serve not only as a photoacoustic contrast agent, but also as a nanoplatform for positron emission tomography (PET) and magnetic resonance imaging (MRI). Traditional passive nanoplatforms require complicated and time-consuming processes for prebuilding reporting moieties or chemical modifications using active groups to integrate different contrast properties into one entity. In comparison, utilizing functional biomarker melanin can greatly simplify the building process. We further conjugated α_vβ₃ integrins, cyclic c(RGDfC) peptide, to MNPs to allow for U87MG tumor accumulation due to its targeting property combined with the enhanced permeability and retention (EPR) effect. The multimodal properties of MNPs demonstrate the high potential of endogenous materials with multifunctions as nanoplatforms for molecular theranostics and clinical translation.