Photosensitive hydrogels: from structure, mechanisms, design to bioapplications.

Hydrogel is a smart material with a three-dimensional network structure and has been widely used in various fields due to its good biodegradability, biocompatibility, and modification. Photosensitive hydrogel is a smart hydrogel, and its amenability to remote, precise control, and flexible and convenient regulation of stimulating factors make it an ideal candidate for use in fields such as biological materials, drug carriers, and sensors. In this review, we discuss the structure, mechanisms, design principles, and bioapplications of photosensitive hydrogels as developed in recent years. Finally, their potential for development and potential future challenges are outlined.

Specifically immobilizing His-tagged allergens to magnetic nanoparticles for fast and quantitative detection of allergen-specific IgE in serum samples.

Fast and accurate detection of specific IgE (sIgE) is essential for diagnosis of allergic diseases. In this study, we developed a nano-capturer Fe3O4@SiO2-NTA based on magnetic nanoparticles with surface modification of Ni-NTA moieties. Results showed that our immunosensor based on the specifically immobilization of recombinant allergen protein on the Fe3O4@SiO2-NTA could realize fast, high efficiency and low-cost detection of sIgEs in serum samples. In vitro experiments demonstrated that the chemiluminescence (CL) response of the immunosensor to sIgEs showed an obviously discrimination between positive and negative serum samples. The CL intensity values were proportional to the sIgE concentrations in the range of 2.52-14.02 ng/mL with detection limit of 0.35 ng/mL, which offered a promising platform for fast and quantitative determination of sIgEs. Furthermore, our method was successfully utilized for allergic disease diagnosis in 46 serum samples and satisfied results were achieved in comparison with the commercial ELISA kit. In particular, by simply changing various recombinant allergen proteins immobilized on the surface of Fe3O4@SiO2-NTA, our strategy showed great potential for high-throughput analysis of allergen screening.

A paper-based chemiluminescence immunoassay device for rapid and high-throughput detection of allergen-specific IgE.

The fast and precise detection of potential allergen-specific immunoglobulin E (sIgE) is imperative for the diagnosis and appropriate treatment of allergic diseases. In this study, we have successfully fabricated a novel paper-based immunoassay device for the detection of sIgE in allergic diseases. We used Can f 1, one of the main dog allergens, as a model allergen to detect sIgE in human sera. To achieve excellent performance, the experimental parameters were optimized. Further, we extended this device for potential applications in the clinical diagnosis of allergic diseases: worthwhile clinical performance in the detection of allergens was achieved as compared to that achieved by commercial enzyme-linked immunosorbent assay (ELISA) kit. Therefore, it was proven that this strategy has the advantages of high-throughput, rapid, sensitive, and highly accurate detection of trace amounts of sIgEs. Furthermore, by simply changing the antigen and antibody, this device could be used for the high-throughput detection of other allergens, so as to achieve multiallergen detection and appropriate desensitization therapy, thereby making it promising in the determination of allergic diseases in clinics.

Fast-Response Fluorogenic Probe for Visualizing Hypochlorite in Living Cells and in Zebrafish.

A fast-response fluorogenic probe-compound D1-for monitoring hypochlorite (ClO- ), based on specific ClO- cleavage of a C=N bond and producing results observable to the naked eye, has been developed. The response of the probe to ClO- increases linearly, and the fluorescence intensity was heightened by a factor of about 25. D1 responses to ClO- , with high selectivity and sensitivity, were observable by naked eye within 10 s. D1 can not only detect levels of hypochlorite in vitro, such as in urine, but is also capable of monitoring hypochlorite content under extremely cold conditions, as low as -78 °C. Meanwhile, its good biocompatibility permitted the use of D1 to detect intracellular ClO- by confocal microscopy. Moreover, D1 was successfully applied to monitor exogenous and endogenous ClO- in zebrafish through fluorescence imaging.

Non-viral nanocarriers for intracellular delivery of microRNA therapeutics.

MicroRNAs are small regulatory noncoding RNAs that regulate various biological processes associated with neurological disorders, cardiovascular diseases, cancer and viral infection. MiRNA-based therapeutics have broad applications including cancer immunotherapy, genomic engineering and protein replacement therapy. Until now, a variety of materials have been proved to be promising as non-viral nanocarriers for intracellular delivery of miRNAs, such as polymeric nanoparticles, lipid nanocapsules, and inorganic nanoparticles, etc. In this review, we will present the strategies for intracellular miRNA delivery, and specially focus on rationally designed routes, their mechanisms of action, and potential therapeutics used in the host cells or in vivo studies. Futhermore, we will also make a conclusion based on the current development. The perspective on the new generation of delivery systems toward the emerging area of miRNA-based therapeutics will be discussed as well.