AbstractRoom-temperature phosphorescent (RTP) materials have great potential for in vivo imaging because they can circumvent the autofluorescence of biological tissues. In this study, a class of organic-doped long-wavelength (≈600 nm) RTP materials with benzo[c][1,2,5] thiadiazole as a guest was constructed. Both host and guest molecules have simple structures and can be directly purchased commercially at a low cost. Owing to the long phosphorescence wavelength of the doping system, it exhibited good tissue penetration (10 mm). Notably, these RTP nanoparticles were successfully used to image atherosclerotic plaques, with a signal-to-background ratio (SBR) of 44.52. This study provides a new approach for constructing inexpensive red organic phosphorescent materials and a new method for imaging cardiovascular diseases using these materials.

Development of the powerful building block is of great significance to construct materials with advanced properties. Herein, for the first time, a triazole-based luminescent core with balanced twist and conjugation is reported, which is explored to construct a D-A near-infrared (NIR) aggregation-induced emission luminogens (TPT-DCM) with high molar extinction coefficient, good brightness and excellent reactive oxygen species generation rate. These features enable it to function as a nanoprobe with ultralong NIR afterglow luminescence (up to 20 days) and ultrahigh tumor-to-liver signal ratio (up to 187) for in vivo deep-tissue afterglow imaging (with depth reaching 1.6 cm), in combination with chemiluminescence resonance energy transfer aided by active Schaap's dioxetane. Moreover, thanks to the excellent properties of the nanoprobe, the afterglow imaging-guided surgery navigation can be successfully conduced to remove the tumors especially with tiny size of < 1 mm. This is particularly useful to eliminate tumor residuals and prevent the cancer recurrence after surgery.

AbstractAdjuvants play an important role in enhancing vaccine-induced immune protection. Adequate cellular uptake, robust lysosomal escape, and subsequent antigen cross-presentation are critical steps for vaccine adjuvants to effectively elicit cellular immunity. Here, a fluorinated supramolecular strategy to generate a series of peptide adjuvants by using arginine (R) and fluorinated diphenylalanine peptide (DP) is adopted. It is found that the self-assembly ability and antigen-binding affinity of these adjuvants increase with the number of fluorine (F) and can be regulated by R. By comparison, 4RDP(F5) shows the strongest binding affinity with model antigen ovalbumin (OVA) and the best performance in dendritic cells maturation and antigen's lysosomal escape, which contributes to the subsequent antigen cross-presentation. As a consequence, 4RDP(F5)-OVA nanovaccine generates a strong cellular immunity in a prophylactic OVA-expressing EG7-OVA lymphoma model, leading to long-term immune memory for resisting tumor challenge. What's more, 4RDP(F5)-OVA nanovaccine in combination with anti-programmed cell death ligand-1 (anti-PD-L1) checkpoint blockade could effectively elicit anti-tumor immune responses and inhibit tumor growth in a therapeutic EG7-OVA lymphoma model. Overall, this study demonstrates the simplicity and effectiveness of fluorinated supramolecular strategies for constructing adjuvants and might provide an attractive vaccine adjuvant candidate for cancer immunotherapy.