Gold Nanorods and Polymer Micelles Mediated Dual TLR Stimulators Delivery System CPG@Au NRs/M-R848 Regulate Macrophages Reprogramming and DC Maturation for Enhanced Photothermal Immunotherapy of Melanoma

Synergistic photothermal immunotherapy has emerged as a favorable therapeutic approach to fight cancer. However, design of an effective photothermal immunotherapy system to suppress tumor growth and simultaneously inhibit tumor metastases continues to be a challenge. Here a dual toll-like receptor agonists delivery system CPG@Au NRs/m-R848 for combined photothermal immunotherapy of melanoma is developed. CPG@Au NRs/m-R848 displays strong antitumor effects by promoting maturation of dendritic cells (DCs) and reprogramming of M2 macrophages into M1 phenotype. Moreover, immunogenic cell death (ICD) induced by photothermal ablation of Au NRs could synergistically produce in situ vaccination effect with CPG ODN and R848, generating systemic and lasting antitumor immunity. It is further proved that CPG@Au NRs/m-R848 treatment inhibits tumor growth in bilateral B16F10 tumors model by eliciting CD8+ T cell response. Overall, this work suggests that this strategy hold great potential in tumor immunotherapy by regulating tumor-associated macrophage polarization, triggering DCs maturation and inducing ICD.

Ethanol-extraction SERS strategy for highly sensitive detection of poisons in oily matrix

The sensitive detection and identification of toxicants in oily matrices have suffered from difficulty in poisoning incidents, therefore it is necessary to develop the rapid and efficient analytical method to realize the on-site screening and analyzing. In this report, the surface-enhanced Raman spectroscopy (SERS) method was used to detect paraquat and diquat poisons in various oily matrix coupled with solvent extraction. The solvent extraction not only remove interfering impurities of oily substrates, but also can enrich and separate the poisons from oily matrix. It was demonstrated that the ethanol as the extractant was suitable for the rapid separation of poisons such as paraquat (PQ) and diquat (DQ) in oily matrix (soy sauce, pasta sauce, sesame oil, chili oil). Moreover, combined with a handheld Raman spectrometer, the entire detection process was completed within 8 min with the level of 10 ppb PQ and 100 ppb DQ. Furthermore, double-blind experiments verify the reliability of this method. The results demonstrate that this rapid and convenient method could be used for the effective enrichment and sensitive detection of poisons in several oily matrix and has the grate potential application in emergency response and public safety.

Droplet array for open-channel high-throughput SERS biosensing

Open-channel and high throughput are two important aspects of clinical diagnosis, correlation biochemical analysis, cell culture techniques and food safety. Here, we propose the mini-pillar based array for open-channel and high-throughput SERS detection of miRNA. The polydimethylsiloxane (PDMS) mini-pillars are used as a high-throughput platform, which have good anchoring and aggregation effects on microdroplets, greatly reducing the amount of analytical solution and facilitate the homogeneous sample distribution after evaporation. The deposited gold nanorods (Au NRs) on the pillars with optimized diameter served as SERS-active substrate, can greatly improve the sensitivity of SERS signal compared to other planar substrates. On the open-channel biological chip, sensitive, simultaneous, and specific detection of breast cancer marker miRNA-1246 can be performed. In this mini-pillar array SERS system, the limit of detection (LOD) is 10^-12 M. The mini-pillar array shows enormous potential for open channel, high-throughput biomolecular detection, providing an opportunity for biomedical point-of-care testing (POCT) and drug screening.

Nitroxide-radicals-modified gold nanorods for in vivo CT/MRI-guided photothermal cancer therapy

Purpose

This article presents a report of the synthesis, characterization, and biomedical application of nitroxide-radicals-modified gold nanorods (Au-TEMPO NRs) for imaging-guided photothermal cancer therapy.

Patients and methods

Au nanorods were synthesized through seed-mediated growth method, 4-Amino-TEMPO was added and the reaction proceeded under magnetic stirring.

Results

With a mean length of 39.2 nm and an average aspect ratio of approximately 3.85, Au-TEMPO NRs showed good photothermal ability when they were irradiated by 808-nm laser. Au-TEMPO NRs could be stored in PBS for more than 1 month, showed no cytotoxicity against both tumor and normal cells at a concentration of up to 3 mg/mL, and functioned as a dual-mode contrast agent for CT/magnetic resonance (MR) imaging in vitro and in vivo, due to their high X-ray attenuation of Au and good r1 relaxivity of nitroxide radicals. Further, they had a long retention time (~4 hours) in the main organs, which enabled a long CT/MR imaging time window for diagnosis. Bio-distribution results revealed that these Au-TEMPO NRs passively aggregated in the liver and spleen. After irradiation by 808-nm laser, Au-TEMPO NRs could ablate the solid tumor in 4T1 tumor-bearing mice, which implied they were a potential theranostic agent for dual-mode imaging and photothermal cancer therapy.

Conclusion

This type of Au-TEMPO NRs with the abilities of CT/MR imaging and photothermal therapy, can play an active role in imaging-guided photothermal cancer therapy.