Hyaluronic Acid-modified Organic Fluorescent Nanoparticles For Imaging Cancer Cells

Nanoprobes with biocompatibility and strong fluorescence properties have unique advantages in tumor detection and diagnosis.Fluorescent nanoparticles,due to their better light stability and multi-functional applicability,are outstanding in cell imaging and biomolecular response.In this paper,two types of nanoparticles based on aggregation-induced emission properties are prepared for the detecting and imaging of tumor cells.They are coated nanoparticles HA-Pha@F-NO₂with dual fluorescence properties and cross-linked nanoparticles HA-Ac-Pha-C formed by UV light.The outer layer of HA-Pha@F-NO₂is a hyaluronic acid-modified molecule with aggregation-induced emission properties,and the boron dipyrromethene derivative molecule with near-infrared emission is coated.The nanoparticle has low critical micelle concentration,small size and high fluorescence intensity.Cytotoxicity experiments showed that when the particle concentration is 80?g/m L,more than 83%of the cells still survived well.Nanoparticle cell imaging experiments demonstrated that it can maintain stable dual red and blue fluorescence in response to cancer cells,and the red fluorescence was further verified by in vitro experiments due to the reduction of the fluorophore by nitroreductase.To improve the fluorescence intensity and stability of the nanoparticles,a new nanoparticle HA-Ac-Pha-C was prepared through a photochemical crosslinking reaction by combining the aggregation-induced emission fluorophore and methacrylic anhydride-modified hyaluronic acid.The fluorescence spectra and Zeta potential experiments determined that the better cross-linking reaction time is 30 s,and the fluorescence intensity and size of the nanoparticle were also characterized in different ways.The photobleaching resistance experiments showed that the crosslinked nanoparticle not only have stronger fluorescence,but also have better photostability and can maintain 85.9%of the original light intensity after 7 days.In addition,cell and zebrafish imaging experiments have also demonstrated that nanoparticles have a specific fluorescent labeling for He La cells and excellent biocompatibility in living organisms.