ABSTRACT
Surface polymer engineering was applied with a carrier of exosomes, namely, the amphiphilic cationic CHP (cCHP) nanogel, to improve the delivery of exosome content by forming complexes with the exosomes. Mouse macrophage cells were used to produce the exosomes, which were then mixed with the cCHP nanogel to form a hybrid. Transmission electron microscopy revealed that the surface of each exosome was coated with cCHP nanogel particles. Flow cytometry also showed a significant uptake of this exosome/nanogel hybrid by HeLa cells, with the main mechanism behind this internalization being endocytosis. A range of different molecules that inhibit different types of endocytosis were also applied to determine the particular pathway involved, with a caveolae-mediated endocytosis inhibitor being revealed to markedly affect the hybrid uptake. Next, we evaluated the fate of the internalized hybrid using fluorescent labeling, with the results suggesting fusion between endosomes and exosomes. Finally, revealing the functional efficacy of this approach, we showed that the nanogel system could successfully deliver functional exosomes into cells, as indicated by its ability to induce neuron-like differentiation in the recipient cells. Overall, our findings show the potential of using this hybrid nanocarrier system for transporting various contents in exosomes and ensuring their effective delivery in a functionally intact state.
Subject(s)
Bioengineering , Drug Delivery Systems , Endocytosis , Exosomes/metabolism , Nanogels/chemistry , Polymers/metabolism , Animals , Cells, Cultured , Exosomes/chemistry , Mice , Particle Size , Polymers/chemistry , RAW 264.7 Cells , Surface PropertiesABSTRACT
Four new alkylating N-methylpyrrole-N-methylimidazole (PI) polyamide conjugates (1-4) with seven-base-pair (bp) recognition ability were synthesized. Evaluation of their DNA-alkylating activity clearly showed accurate alkylation at match site(s). The cytotoxicities of conjugates 1-4 were determined against six human cancer cell lines, and the effect of these conjugates on the expression levels of the whole human genome in A549 cells were also investigated. A few genes among the top 20 genes were commonly downregulated by each conjugate, which reflects their sequence specificity. Conversely, many of the top 10 genes were commonly upregulated, which may have been caused by alkylation damage to DNA. Moreover, the antitumor activities of the PI polyamide conjugates 2 and 3 were investigated using nude mice transplanted with DU145 or A549. The intravenous administration of each liposomal conjugate in water yielded tumor-suppressing effects specifically toward DU145 cells and not A549 cells, which was pertinent to cytotoxicity.
