[Angelica sinensis polysaccharide-chitosan nanosystem synergizes with radiotherapy to enhance anti-tumor immunity and suppress tumor growth].

To enhance the immunomodulatory effect of Angelica sinensis polysaccharide(ASP) on the tumor microenvironment, this study prepared ASP-chitosan nanoparticles(ASP-NPs) using a molecular self-assembly technique. The preparation process was optimized through single-factor investigation. The results from dynamic light scattering and transmission electron microscopy showed that ASP-NPs had a particle size of(313.1±23.3) nm, with uniform distribution and regular morphology. In the 4T1 breast cancer mouse model, ASP-NPs combined with radiotherapy(RT) significantly inhibited tumor growth through two administration routes(intratumoral injection and intravenous injection): the tumor inhibition rate reached 69% in the intratumoral injection group and 47% in the intravenous injection group, both significantly higher than that of the RT group(P