Seamless Integration of Rapid Separation and Ultrasensitive Detection for Complex Biological Samples Using Multistage Annular Functionalized Carbon Nanotube Arrays.

Efficient separation, enrichment, and detection of bacteria in diverse media are pivotal for identifying bacterial diseases and their transmission pathways. However, conventional bacterial detection methods that split the separation and detection steps are plagued by prolonged processing times. Herein, a multistage annular functionalized carbon nanotube array device designed for the seamless integration of complex biological sample separation and multimarker detection is introduced. This device resorts to the supersmooth fluidity of the liquid sample in the carbon nanotubes interstice through rotation assistance, achieving the ability to quickly separate impurities and capture biomarkers (1 mL sample cost time of 2.5 s). Fluid dynamics simulations show that the reduction of near-surface hydrodynamic resistance drives the capture of bacteria and related biomarkers on the functionalized surface of carbon nanotube in sufficient time. When further assembled as an even detection device, it exhibited fast detection (<30 min), robust linear correlation (101-107 colony-forming units [CFU] mL-1, R2 = 0.997), ultrasensitivity (limit of detection = 1.7 CFU mL-1), and multitarget detection (Staphylococcus aureus, extracellular vesicles, and enterotoxin proteins). Collectively, the material and system offer an expanded platform for real-time diagnostics, enabling integrated rapid separation and detection of various disease biomarkers.

Dual-Antigen-Loaded Hepatitis B Virus Core Antigen Virus-like Particles Stimulate Efficient Immunotherapy Against Melanoma.

Tumor cells are rich in antigens, which provide a reliable antigen library for the design of personalized vaccines. However, an effective tumor vaccine vector that can efficiently deliver antigens to lymphoid organs to stimulate strong CD8+ cytotoxic T-lymphocyte immune response is still lacking. Here we designed a dual-antigen delivery system based on hepatitis B virus core antigen virus-like particles (HBc VLPs). We first confirmed that different antigen-loaded HBc VLP monomers could be assembled into nanoparticles (hybrid VLPs). Hybrid VLPs could slightly enhance bone marrow-derived dendritic cell maturation in vitro. Strikingly, hybrid VLPs could generate antigen-specific antitumor immunity and innate immunity in vivo which could significantly inhibit tumor growth or metastatic formation in a subcutaneous tumor or lung metastatic tumor model, respectively. Moreover, dual-epitope vaccination generated enhanced T-cell responses that potently inhibited tumor growth and metastatic formation. Together, this study provides a new powerful concept for cancer immunotherapy and suggests a novel design for VLP-based personalized nanomedicine.

Upconversion nanoparticle and gold nanocage satellite assemblies for sensitive ctDNA detection in serum.

A rapid molecular diagnostic technique targeting circulating tumor DNA (ctDNA) has become one of the most clinically significant liquid biopsy methods for non-invasive and timely diagnosis of cancer. Herein, a sensitive detection system of ctDNA based on a fluorescence resonance energy transfer (FRET) system using upconversion nanoparticles (UCNPs) and gold nanocages (AuNCs) was constructed. Through the doping of Yb and Tm ions, the excitation and emission wavelengths of UCNPs were adjusted to 980 nm and 806 nm, respectively. Subsequently, UCNPs and AuNCs with the corresponding wavelength absorption were linked by complementary pairing of surface-modified DNA to form near-infrared fluorescent nanoprobes (NIR probes). Targeting DNA mutation recognition and signal transduction were realized by using NIR probes through the toehold-mediated strand displacement reaction. This method could detect a single point mutation of the KRAS gene with a wide detection range from 5 pM to 1000 pM and the limit of detection reached 6.30 pM. More importantly, the stable and highly specific NIR probes could be directly used in the serum environment without complicated pretreatment and amplification processes in advance. It could be envisioned that this specific and sensitive ctDNA detection strategy has great potential in clinical diagnosis and monitoring of diverse malignant tumors.