Photoacoustic and Colorimetric Visualization of Latent Fingerprints

There is a high demand on a simple, rapid, accurate, user-friendly, cost-effective, and nondestructive universal method for latent fingerprint (LFP) detection. Herein, we describe a combination imaging strategy for LFP visualization with high resolution using poly(styrene-<i>alt</i>-maleic anhydride)-<i>b</i>-polystyrene (PSMA-<i>b</i>-PS) functionalized gold nanoparticles (GNPs). This general approach integrates the merits of both colorimetric imaging and photoacoustic imaging. In comparison with the previous methods, our strategy is single-step and does not require the signal amplification by silver staining. The PSMA-<i>b</i>-PS functionalized GNPs have good stability, tunable color, and high affinity for universal secretions (proteins/polypeptides/amino acids), which makes our approach general and flexible for visualizing LFPs on different substrates (presumably with different colors) and from different people. Moreover, the unique optical property of GNPs enables the photoacoustic imaging of GNPs-deposited LFPs with high resolution. This allows observation of level 3 hyperfine features of LFPs such as the pores and ridge contours by photoacoustic imaging. This technique can potentially be used to identify chemicals within LFP residues. We believe that this dual-modality imaging of LFPs will find widespread use in forensic investigations and medical diagnostics

Tumor-Homing and Immune-Reprogramming Cellular Nanovesicles for Photoacoustic Imaging-Guided Phototriggered Precise Chemoimmunotherapy

Many studies have focused on developing effective therapeutic strategies to selectively destroy primary tumors, eliminate metastatic lesions, and prevent tumor recurrence with minimal side effects on normal tissues. In this work, we synthesized engineered cellular nanovesicles (ECNVs) with tumor-homing and immune-reprogramming functions for photoacoustic (PA) imaging-guided precision chemoimmunotherapy. M1-macrophage-derived cellular nanovesicles (CNVs) were loaded with gold nanorods (GNRs), gemcitabine (GEM), CpG ODN, and PD-L1 aptamer. The good histocompatibility and tumor-homing effect of CNVs improved drug retention in the bloodstream and led to their enrichment in tumor tissues. Furthermore, the photothermal ability of GNRs enabled PA imaging-guided drug release. GEM induced tumor immunogenic cell death (ICD), and CpG ODN promoted an immune response to the antigens released by ICD, leading to long-term specific antitumor immunity. In addition, the PD-L1 aptamer relieved the inhibitory effect of the PD1/PD-L1 checkpoint on CD8+ T-cells and augmented the immunotherapeutic effect. The synergistic innate and adaptive immune responses enhanced the antitumor effect of ECNVs. In summary, this nanoplatform integrates local targeted photothermal therapy with extensive progressive chemotherapy and uses ICD to reshape the immune microenvironment for tumor ablation

Gold Nanoparticle Coated Carbon Nanotube Ring with Enhanced Raman Scattering and Photothermal Conversion Property for Theranostic Applications

We report a new type of carbon nanotube ring (CNTR) coated with gold nanoparticles (CNTR@AuNPs) using CNTR as a template and surface attached redox-active polymer as a reducing agent. This nanostructure of CNTR bundle embedded in the gap of closely attached AuNPs can play multiple roles as a Raman probe to detect cancer cells and a photoacoustic (PA) contrast agent for imaging-guided cancer therapy. The CNTR@AuNP exhibits substantially higher Raman and optical signals than CNTR coated with a complete Au shell (CNTR@AuNS) and straight CNT@AuNP. The extinction intensity of CNTR@AuNP is about 120-fold higher than that of CNTR at 808 nm, and the surface enhanced Raman scattering (SERS) signal of CNTR@AuNP is about 110 times stronger than that of CNTR, presumably due to the combined effects of enhanced coupling between the embedded CNTR and the plasmon mode of the closely attached AuNPs, and the strong electromagnetic field in the cavity of the AuNP shell originated from the intercoupling of AuNPs. The greatly enhanced PA signal and photothermal conversion property of CNTR@AuNP were successfully employed for imaging and imaging-guided cancer therapy in two tumor xenograft models. Experimental observations were further supported by numerical simulations and perturbation theory analysis