Search

Serum lipid metabolites have been emerging as ideal biomarkers for disease diagnosis and prediction. In the current stage, nontargeted or targeted lipidomic research mainly relies on a liquid chromatography-mass spectrometry (LC-MS) platform, but future clinical applications need more robust and high-speed platforms. Surface-assisted laser desorption ionization mass spectrometry (SALDI-MS) has shown excellent advantages in the high-speed analysis of lipid metabolites. However, the platform in the positive ion mode is more inclined to target a certain class of lipids, leading to the low coverage of lipid detection and limiting its practical translation to clinical applications. Herein, we proposed a dual-mechanism-driven strategy for high-coverage detection of serum lipids on a novel SALDI-MS target, which is a composite nanostructure comprising vertical silicon nanowires (VSiNWs) decorated with AuNPs and polydopamine (VSiNW-Au-PDA). The performance of laser desorption and ionization on the target can be enhanced by charge-driven desorption coupled with thermal-driven desorption. Simultaneous detection of 236 serum lipids (S/N ≥ 5) including neutral and polar lipids can be achieved in the positive ion mode. Among these, 107 lipid peaks were successfully identified. When combined with VSiNW-Au-PDA and VSiNW chips, 479 lipid peaks can be detected in serum samples in positive and negative ion modes, respectively. Based on the platform, serum samples from 57 hepatocellular carcinoma (HCC) patients and 76 healthy controls were analyzed. After data mining, 14 lipids containing different lipid types (TAG, CE, PC) were selected as potential lipidomic biomarkers. With the assistance of an artificial neural network, a diagnostic model with a sensitivity of 92.7% and a specificity of 96% was constructed for HCC diagnosis.

Spatially resolved tissue lipidomics is essential for accurate intraoperative and postoperative cancer diagnosis by revealing molecular information in the tumor microenvironment. Matrix-free laser desorption ionization mass spectrometry imaging (LDI-MSI) is an emerging attractive technology for label-free visualization of metabolites distributions in biological specimens. However, the development of LDI-MSI technology that could conveniently and authentically reveal molecular distribution on tissue samples is still a challenge. Herein, we present a tissue imprinting technology by retaining tissue lipids on 2D nanoflakes-capped silicon nanowires (SiNWs) for further mass spectrometry imaging and cancer diagnosis. The 2D nanoflakes were prepared by liquid exfoliation of molybdenum disulfide (MoS

Elevated hydrogen sulfide (H2S) level is closely associated with various diseases. So the sensing of H2S is noteworthy for divulging its role in diagnosing these diseases. Herein, we proposed poly(acrylic acid)-modified upconversion nanoparticles assembled with cationic near-infrared cyanine chromophores (Cy7-Cl) as the nanoprobe (Cy7-UCNPs) for monitoring H2S based on thiolation reactions. The presence of H2S resulted into about five-fold enhancement in the luminescence intensity of Cy7-UCNPs and the nanoprobe showed a good linearity (R2 =0.9952) over the range of 1.0 − 90 μM. Furthermore, Cy7-UCNPs were successfully employed in sensing and imaging of exogenous and endogenous H2S in live cells and zebrafish. The system shows great potential in the field of nanobiomedicine because of the many excellent properties including high sensitivity, good selectivity, and low cytotoxicity.

Nanoassemblies for bioimaging in living cells have attracted much attention. In this work, an efficient and sensitive turn-on fluorescent detection platform for reactive oxygen species (ROS) in living cells has been constructed using the nanoassemblies of upconversion nanoparticles (UCNPs)-MoS2 nanoflakes. In this nanostructure, the positively charged UCNPs could assemble with negatively charged poly(acrylic acid) modified MoS2 nanoflakes by electrostatic force, which led to the remarkable fluorescence quenching of UCNPs owing to the excellent quenching ability of MoS2 nanoflakes. In contrast, in the presence of ROS, the fluorescence recovery of UCNPs is successfully realized owing to the decomposition of MoS2 nanoflakes through the chemical reaction with ROS. The ROS-mediated disassembly of the nanoarchitecture display excellent fluorescent response toward ROS. Furthermore, the disassembly of UCNPs-MoS2 nanoflakes has been successfully used for ROS bioimaging in cells and zebrafish.

Due to the abuse of antibiotics, antimicrobial resistance is rapidly emerging and becoming a major global risk for public health. Thus, there is an urgent need for reducing the use of antibiotics, finding novel treatment approaches, and developing controllable release systems. In this work, a dual synergistic antibacterial platform with on-demand release ability based on silver nanoparticles (AgNPs) and antimicrobial peptide (AMP) coloaded porous silicon (PSi) was developed. The combination of AgNPs and AMPs (Tet-213, KRWWKWWRRC) exhibited an excellent synergistic antibacterial effect. As a carrier, porous silicon can efficiently load AgNPs and AMP under mild conditions and give the platform an on-demand release ability and a synergistic release effect. The AgNPs and AMP coloaded porous silicon microparticles (AgNPs-AMP@PSiMPs) exhibited an acid pH and reactive oxygen species (ROS)-stimulated release of silver ions (Ag+) and AMPs under bacterial infection conditions because of oxidation and desorption effects. Moreover, the release of the bactericide could be promoted by each other due to the interplay between AgNPs and Tet-213. In vitro antibacterial tests demonstrated that AgNPs-AMP@PSiMPs inherited the intrinsic properties and synergistic antibacterial efficiency of both bactericides. In addition, wound dressing loaded with AgNPs-AMP@PSiMPs showed outstanding in vivo bacteria-killing activity, accelerating wound-healing, and low biotoxicity in aStaphylococcus aureus-infected rat wound model. The present work demonstrated that PSiMPS might be an efficient platform for loading the antibiotic-free bactericide, which could synergistically and on-demand release to fight wound infection and promote wound healing.

High heterogeneity of hepatocellular carcinoma (HCC) tumor has become an obstacle to select effective therapy for the treatment of HCC patients. Methods that can guide the decision on therapy choice for HCC treatment are highly demanded. Evaluating the drug response of heterogeneous tumor cells at the molecular level can help to reveal the toxicity mechanism of anticancer drugs and provide more information than current cell-based chemosensitivity assays. In the present work, nanostructure-assisted laser desorption/ionization mass spectrometry (NALDI-MS) was used to investigate the lipid response of HCC cells to anticancer drugs. Three types of HCC cells (LM3, Hep G2, Huh7) were treated with sorafenib, doxorubicin hydro-chloride, and cisplatin. We found that the lipid profiles of HCC cells changed a lot after the drug treatment, and the degree of lipid changes was related to the cell viability. Two pairs of fatty acids C16:1/C16:0 and C18:1/C18:0 were found to be strongly related to the viability of HCC cells after drug treatment, and were more sensitive than Methyl-thiazolyl tetrazolium (MTT) assay. Accordingly, they can act as sensitive and comprehensive indexes to evaluate the drug susceptibility of HCC cells. In addition, the peak ratio of several neighboring phospholipids displayed high correlation with drug response of specific cell subtype to specific drug. The ratio of neighboring lipids may be traced back to the activity of enzyme and gene expression which regulate the lipidomic pathway. This method provides drug response of heterogenous tumor cells at molecular level and could be a potential candidate to precise tumor chemosensitivity assay.

Elevated hydrogen sulfide (H