Animal cells have complicated dynamics of cell membrane structures which require desirable dyes for in vivo imaging. Here, an asymmetric amphiphilic zwitterionic perylenediimide (ZP) derivative has been constructed by introducing an octyl chain and a zwitterionic head to each imide position of perylenediimide chromophore. ZP could self-assemble into vesicles in aqueous solution. The aggregated ZP vesicles have been explored to image cell inner or surface membrane structures by a controlled disassembly process. After being taken up into cells, ZP vesicles disassemble into monomers and then incorporate into cell inner membranes. The vesicles can also disassemble in acid food and incorporate into cell surface membrane of gut cells. The research provides a new tool to label the complicated cell membrane structures with up to 3 days long-term labeling for life science applications.Keywords: amphiphilic; assembly; cell membrane; perylenediimide; zwitterionic;

Biopesticides are widely utilized for organic and green food production. One representative case is Helicoverpa armigera nucleopolyhedrovirus (HaNPV), which has strong pesticidal effects on its only host, cotton bollworm. HaNPV cannot infect and kill other pests, probably due to the lack of virus receptors in the intestinal cells of other pests. The narrow infection range of pests is a main restriction factor in the field application of insect viruses. Herein, we have utilized two types of perylenediimide-cored cationic nanocarriers to efficiently deliver HaNPV deoxyribonucleic acid (DNA) in vitro and in vivo and to kill non-host pests. Both fluorescent nanocarriers can condense HaNPV DNA into stable complexes. Non-host insect cells treated with the complexes show severe cell death. In vivo tests on two non-host insect species demonstrate that the nanocarrier delivery system can efficiently broaden the host range of virus DNA. Our work paves a novel way to extend the application range of insecticidal viruses via nanocarrier delivery systems.

We report the delivery of a hydrophobic pesticide, thiamethoxam, by water-soluble nanosized cationic dendrimers that contain hydrophobic dendritic polyesters and peripheral amines, demonstrated by DLS, spectral analysis and ITC. The dendrimer-based nanocarrier can efficiently deliver the pesticide into the live cells and largely increase the cytotoxicity of the drug.

A novel amphiphilic squarylium indocyanine (LysoCy) is reported for remarkable lysosome tracking in live cells. LysoCy performs as a promising lysosome tracker with low cytotoxicity, a strong binding affinity and clear subcellular labelling. The long-term dynamics of lysosomes can be revealed by LysoCy for up to 2 days of culture, while the working duration of commercial dye is no longer than 1 hour. Our work provides a good alternative tool for long-term live cell imaging.

The molecular properties concerning size, shape, and electric charges of the planar aromatic DNA intercalators are still poorly understood. Herein, a series of water-soluble perylene bisimide (PBI) derivatives containing a rigid and planar aromatic nanoscaffold with different size, shape, and electric charges were synthesized. Using histochemistry and cell viability assays on animal tissues and cancer cells, we revealed the molecular properties required for successful DNA intercalators to localize in cell nuclei and inhibit cancer cells. Small molecular size and the strong polarity of hydrophilic substituents are prerequisites for PBI-based DNA intercalators. A large number of charges facilitate the nucleic accumulation of these DNA intercalators, while fewer charges and planar aromatic nanoscaffold more efficiently inhibit cancer cell growth.Keywords: anticancer activity; cell imaging; DNA intercalator; nucleic accumulation; perylene bisimide; planar aromatic nanoscaffold;

A cationic fluorescence nanoparticle efficiently enters plants with high transfection efficacy. Applying a mixture of G2/dsRNA to the model plant, Arabidopsis root, leads to significant reduction in the expression of important developmental genes and results in apparent phenotypes. This study reports a non-viral gene nanocarrier which triggers gene silencing in plants and leads to systemic phenotypes.

A water-soluble cationic dendrimer with a central fluorescent perylenediimide (PDI) chromophore and many peripheral amines can rapidly penetrate into live hemocytes, gut and fat body. By double fluorescence tracing, the dendrimer is demonstrated to have a high gene-transfection capacity. The synthesized dsRNA targeting at serpin-3, a key immune gene, is systemically delivered by the dendrimer to insect fat bodies and hemocytes outside of midgut. Biological assays, including PCR and immunoblotting, show that the expressions of the target gene and its downstream immunity-related genes are largely suppressed. This study demonstrates for the first time that a PDI-cored, cationic, dendrimer-mediated dsRNA systemically interferes with the immune response in insects. This work provides an insect model for immunology research and a novel strategy for potential pest control.

A highly water-soluble perylenediimide-core poly(amido amine) (PDI-PAmAm) with peripheral amine groups has been synthesized. The central PDI chromophore allows optical monitoring of relevant cellular experiments by fluorescence microscopy. The PAmAm shell provides the steric bulk that notably suppresses the aggregation of the central PDI chromophore in aqueous solution. The peripheral amines provide water solubility and positive charges, and also serve as active sites for the further growth of PAmAm. PDI-PAmAm can be rapidly internalized into live cells with high efficacy of gene delivery and low cytotoxicity. Both in vitro and in vivo experiments demonstrate the high gene transfection efficacy of PDI-PAmAm.

Multifunctional dithioacetal-modified perylenediimide (DTPDI) is synthesized as a highly sensitive and selective fluorescent chemosensor for recyclable Hg2+ detection and an effective DNA carrier. The central PDI chromophore allows the tracing of cell uptake by fluorescence microscopy, dithioacetals enable the detection of Hg2+, and peripheral amine hydrochloride salts increase the water solubility and also serve as positive charges for noncovalent binding of negatively charged DNA. In addition to serve as a recyclable fluorescent probe for Hg2+ detection, DTPDI can be rapidly internalized into live cells with low cytotoxicity and high DNA delivery efficacy.

Two star polycations, poly(2-aminoethyl methacrylate) (PAEMA, P1) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA, P2), have been synthesized with perylene diimide (PDI) as the central fluorophore. 1H NMR and 13C NMR are used to confirm the successful synthesis of a macromolecular initiator. Using ATRP strategy, P1 and P2 are obtained with narrow molecular weight distribution. The star polymers have good fluorescence properties in aqueous solution, which provides fluorescent tracing and imaging during gene delivery. Both P1 and P2 can efficiently condense DNA into stable nanoparticles. Transfection studies demonstrate that P1 and P2 deliver DNA into live cells with higher efficiency and lower cytotoxicity than polyethylenimine (PEI, 25 kDa). P2 shows higher capacity for gene delivery than P1 due to its better buffering and faster rate of cellular internalization.Keywords: bioimaging; fluorescence; gene vector; star polymer

•omb and Iro-C are complementary expressed along the H/N fold of wing discs.•Dpp-Omb signaling unidirectionally restricts the Iro-C expression domain.•Asymmetric Omb and Iro-C patterns are necessary for H/N fold formation.Animal morphogenesis requires folds or clefts to separate populations of cells which are often associated with different cell affinities. In the Drosophila wing imaginal disc, the regional expression of the Iroquois complex (Iro-C) in the notum leads to the formation of the hinge/notum (H/N) fold that separates the wing hinge and notum territories. Although Decapentaplegic (Dpp) signaling has been revealed as essential for the hinge/notum subdivision through the restriction of Iro-C toward the notum region, the mechanism by which the H/N border develops into a fold is unknown. Here, we report that a Dpp target gene, optomotor-blind (omb), mediates the role of Dpp signaling in Iro-C inhibition. omb is complementarily expressed on the dorsal hinge side, abutting the Iro-C domain along the H/N border. Ectopic omb expression inhibits Iro-C in the notum territory, independent of known Iro-C regulators Msh and Stat92E. Uniform manipulation of either omb or Iro-C genes spanning the presumptive H/N border significantly suppresses H/N fold formation via inhibition of the apical microtubule enrichment. Ectopically sharp border or discontinuity in level of Iro-C or Omb is enough to generate ectopic fold formation. These results reveal that omb and Iro-C not only are complementarily expressed but also cooperate to promote H/N fold formation. Our data help to understand how Dpp signaling is interpreted region-specifically during tissue subdivision.

A water-soluble cationic dendrimer with a central fluorescent perylenediimide (PDI) chromophore and many peripheral amines can rapidly penetrate into live hemocytes, gut and fat body. By double fluorescence tracing, the dendrimer is demonstrated to have a high gene-transfection capacity. The synthesized dsRNA targeting at serpin-3, a key immune gene, is systemically delivered by the dendrimer to insect fat bodies and hemocytes outside of midgut. Biological assays, including PCR and immunoblotting, show that the expressions of the target gene and its downstream immunity-related genes are largely suppressed. This study demonstrates for the first time that a PDI-cored, cationic, dendrimer-mediated dsRNA systemically interferes with the immune response in insects. This work provides an insect model for immunology research and a novel strategy for potential pest control.

Multifunctional dithioacetal-modified perylenediimide (DTPDI) is synthesized as a highly sensitive and selective fluorescent chemosensor for recyclable Hg2+ detection and an effective DNA carrier. The central PDI chromophore allows the tracing of cell uptake by fluorescence microscopy, dithioacetals enable the detection of Hg2+, and peripheral amine hydrochloride salts increase the water solubility and also serve as positive charges for noncovalent binding of negatively charged DNA. In addition to serve as a recyclable fluorescent probe for Hg2+ detection, DTPDI can be rapidly internalized into live cells with low cytotoxicity and high DNA delivery efficacy.

A highly water-soluble perylenediimide-core poly(amido amine) (PDI-PAmAm) with peripheral amine groups has been synthesized. The central PDI chromophore allows optical monitoring of relevant cellular experiments by fluorescence microscopy. The PAmAm shell provides the steric bulk that notably suppresses the aggregation of the central PDI chromophore in aqueous solution. The peripheral amines provide water solubility and positive charges, and also serve as active sites for the further growth of PAmAm. PDI-PAmAm can be rapidly internalized into live cells with high efficacy of gene delivery and low cytotoxicity. Both in vitro and in vivo experiments demonstrate the high gene transfection efficacy of PDI-PAmAm.

A novel amphiphilic squarylium indocyanine (LysoCy) is reported for remarkable lysosome tracking in live cells. LysoCy performs as a promising lysosome tracker with low cytotoxicity, a strong binding affinity and clear subcellular labelling. The long-term dynamics of lysosomes can be revealed by LysoCy for up to 2 days of culture, while the working duration of commercial dye is no longer than 1 hour. Our work provides a good alternative tool for long-term live cell imaging.