Polymorphic strategies for encapsulating polyindole@nido-carborane fluorescent polymeric nanocapsules: Their release, imaging, and biological evaluation in the gastrointestinal microenvironment

Abstract

In this experiment, by combining water-soluble nido-carborane with indole dyes, and used non-toxic and non-irritating sodium alginate and acrylic resin as coating materials to obtain four fluorescent complexes, indol-nido-carborane-sodium alginate- Polymer-A (INS-A) 、indol-nido-carborane-sodium alginate-Polymer-B (INS-B)、indol-nido-carborane-sodium alginate-Polymer-C (INS-C) and indol-nido-carborane-sodium alginate-Polymer-D (INS-D).The transmission electron microscopy (TEM) results showed that the four complexes have different morphologies, with INS-A showing irregular clusters, INS-B being uniformly spherical, INS-C demonstrating a cashew-nut shape and INS-D manifesting a semi-encapsulated state. The spectroscopic properties and in vitro release experiments of the four complexes were performed in different simulated gastrointestinal environments. The results indicated that INS-A and INS-C had excellent photophysical properties and high cumulative release, so INS-A and INS-C were selected for subsequent experiments. Atomic Force Microscope (AFM) test manifested that the surfaces of INS-A and INS-C were relatively smooth. Imaging of HeLa cells with different channels was performed, the Pearson correlation coefficients of both INS-A and INS-C could be calculated to be distributed between 0.21 and 0.60, indicating that the complexes exhibited good imaging performance and could enter the cell and distribute around the nucleus. The results of cell proliferation toxicity (CCK8) experiments showed that at the concentration of 125 μg/mL, the inhibition rates of INS-A and INS-C on HCT-116 and HeLa cells were 47.15 %, 36.70 % and 42.81 %, 35.52 %, respectively, demonstrating that the complexes had an inhibitory effect on cancer cells. In summary, the fluorescent complexes prepared in this paper have good imaging ability and tumor targeting, and are potential fluorescent anticancer reagent.