Biosensing Applications Of Hyaluronic Acid And Water-soluble Conjugated Polymer

In recent years, the unique optoelectronic properties of water soluble conjugated polymer haveshown extensive applications in OLED, organic solar cells, organic storage materials, field effecttransistor and chemical and biological sensors. In the field of chemical and biological sensing,water-soluble conjugated polymers are environment-friendly due to their water solubility. Throughelectrostatic interactions between the polymer and quenchers with opposite charges, tumor markerscan recognized, or trace substances in the surrounding environment can be detected by electron orenergy transfer. Hyaluronic acid, as a good biological compatib le substance, is easy to bechemically modified, and target tumor cells mediated by receptors CD44, and thus realize diseasediagnosis and treatment. In this paper, taking advantage of the water-soluble conjugated polymersand the characteristics of hyaluronic acid at the same time, we modified the hyaluronic acid withfluorescent molecule, or conjugated it with drug molecules, and conducted some novel studies influorescent sensor. The main research work includes the following aspects:1. We established a new method to detect CD44using a probe based on cationic conjugatedpolymers/fluorescein modified hyaluronic acid. Cationic conjugated polymers combined withfluorescein modified hyaluronic acid through electrostatic attraction, and fluorescence resonanceenergy transfer occurred between them. When adding CD44, it can bind specifically withhyaluronic acid, the distance between cationic conjugated polymer and fluorescein groupincreased, thus energy transfer efficiency was reduced. The results showed that the decreases ofenergy transfer efficiency were associated with the concentration of CD44. This method was time-saving, exhibit low prices and fast response speed, and the detection limit of the CD44can reach2.3310-8g/mL. This method can also be extended to the detection of other substances of specificreceptor of HA. This paper also used TEM, DLS, Zeta Potential to explore the mechanism ofdetection, and applied the materials in cell imaging.2. We conjugated hyaluronic acid with antitumor doxorubicin. Cationic conjugated polymerscombined with doxorubicin-hyaluronic acid through electrostatic attraction, electron transferoccurred between them, and the fluorescene of polymer was quenched. Hyaluronidaseoverexpressed in tumor cells together, it can degrade hyaluronic acid, thus doxorubicin was released,and the fluorescence of polymer recovered. Since hyaluronic acid targeting CD44molecule on thecell membrane, this nano-material can also be used in targeted therapy.