A smartphone-integrated portable platform based on polychromatic ratiometric fluorescent paper sensors for visual quantitative determination of norfloxacin.

The emergence of "superbugs" due to antibiotics overuse poses a significant threat to human health and security. The development of sensitive and effective antibiotics detection is undoubtedly a prerequisite for addressing antibiotics overuse-associated issues. However, current techniques for monitoring antibiotics typically require costly equipment and well-trained professionals. Hence, we developed herein a rapid, instrument-free, and on-site detection method for antibiotic residues such as norfloxacin (NOR) based on a ratiometric sensing platform utilizing "on-off-on" response properties of polychromatic fluorescence for direct visual quantitative NOR analysis. Specifically, this platform integrated iron ions (Fe3+)-chelated blue carbon dots (BCDs) for signal sensing and red carbon dots (RCDs) as an internal reference. The sensor mechanism is selective quenching of BCDs' blue fluorescence by Fe3+ via an inner filter effect with unaffected RCDs' red fluorescence. Further NOR addition led to competitive binding with BCDs due to Fe3+ shedding from the BCDs' surface for a recovered blue fluorescence signal. Notably, the ratiometric fluorescence sensor demonstrated rapid and highly sensitive NOR detection in a concentration range of 1-70 µM with an impressive detection limit of 6.84 nM. The ratiometric fluorescence sensing platform was constructed by integrating smartphone and paper-based strategies, which exhibited exceptional sensitivity, selectivity, and rapid response for portable, instrument-free, visual quantification of NOR in real samples.

A Sodium Alginate-Based Multifunctional Nanoplatform for Synergistic Chemo-Immunotherapy of Hepatocellular Carcinoma.

Efficient hepatocellular carcinoma (HCC) treatment remains a significant challenge due to the inherent limitations of traditional strategies. The exploration of polysaccharides' natural immunity for HCC immunotherapy is rarely explored. For this purpose, facile construction of a multifunctional nanoplatform, biotinylated aldehyde alginate-doxorubicin nano micelle (BEACNDOXM) is reported in this study for synergistic chemo-immunotherapy by using constant ß-D-mannuronic acid (M) units and modulated α-L-guluronic acid (G) units in the alginate (ALG) structure. The M units show natural immunity and specific binding ability with mannose receptors (MRs) via strong receptor-ligand interactions, and the G units serve as highly reactive conjugation sites for biotin (Bio) and DOX. Therefore, this formulation not only integrates the natural immunity of ALG and the immunogenic cell death (ICD) triggering function of DOX, but also shows dual targeting properties to HCC cells via MRs and Bio receptors (BRs)-mediated endocytosis. Notably, BEACNDOXM mediates a tumor inhibitory efficiency 12.10% and 4.70% higher than free DOX and single targeting aldehyde alginate-doxorubicin nano micelle controls, respectively, at an equivalent DOX dose of 3 mg kg-1 in Hepa1-6 tumor-bearing mice. This study reports the first example of integrating the natural immunity of ALG and the ICD effect of anticancer drugs for enhanced chemo-immunotherapy of HCC.

Promotion of ICD via Nanotechnology.

Immunotherapy represents the most promising treatment strategy for cancer, but suffers from compromised therapeutic efficiency due to low immune activity of tumor cells and an immunosuppressive microenvironment, which significantly hampers the clinical translations of this treatment strategy. To promote immunotherapy with desired therapeutic efficiency, immunogenic cell death (ICD), a particular type of death capable of reshaping body's antitumor immune activity, has drawn considerable attention due to the potential to stimulate a potent immune response. Still, the potential of ICD effect remains unsatisfactory because of the intricate tumor microenvironment and multiple drawbacks of the used inducing agents. ICD has been thoroughly reviewed so far with a general classification of ICD as a kind of immunotherapy strategy and repeated discussion of the related mechanism. However, there are no published reviews, to the authors' knowledge, providing a systematic summarization on the enhancement of ICD via nanotechnology. For this purpose, this review first discusses the four stages of ICD according to the development mechanisms, followed by a comprehensive description on the use of nanotechnology to enhance ICD in the corresponding four stages. The challenges of ICD inducers and possible solutions are finally summarized for future ICD-based enhanced immunotherapy.