Preparation method and application of hydroxycamptothecin-loaded colon cancer targeted drug delivery system

The invention discloses a preparation method and application of a hydroxycamptothecin-loaded colon cancer targeted drug delivery system. The drug delivery system is composed of HCPT and ferritin (Fn), the characteristic that HCPT is dissolved in an alkaline solution and is insoluble in a weak acid environment is utilized, open-ring-shaped HCPT is wrapped in Fn under the alkaline condition through a solvent evaporation method, the open-ring-shaped HCPT is converted into lactone-type hydroxycamptothecine under the weak acid condition, the solubility is reduced, and therefore HCPT is efficiently loaded into Fn (HCPT at Fn). The HCPT (at) Fn can be combined with transferrin receptor-1 highly expressed on the surface of a colon cancer cell to promote efficient accumulation of HCPT in the colon cancer cell, and lactone type HCPT is released in a lysosome acid environment to efficiently kill the colon cancer cell. 本发明公开了一种负载羟基喜树碱的结肠癌靶向递药系统的制备方法和应用。该递药系统的组成为HCPT和铁蛋白(Fn)，利用HCPT在碱性溶液中溶解，在弱酸性环境中难溶的特点，通过溶剂挥发法在碱性条件下将开环形HC