Aim: To improve the treatment efficacy of anti-tumor drug mitoxantrone, the conjugation of mitoxantrone-loaded nanospheres and anti-C-erbB-2 monoclonal antibodies were prepared.
Methods: Mitoxantrone-loaded nanospheres were prepared with emulsion-heating solidification technique. A heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP), was used as the crosslinker of mitoxantrone-loaded nanospheres and anti-C-erbB-2 monoclonal antibodies; pharmaceutical properties of immunonanocapsuls were studied; the conjugates of nanospheres and monoclonal antibodies was confirmed with immunological methods such as slide agglutination test, fluorescent immunossay and rosset formation test, fluorescent staining and scanning electron microscope.
Results: Mitoxantrone-loaded nanospheres were spherical, with smooth surface and median diameter of 0.665 micron. When stored at 3-5, 20-25 and 37 degrees C, RH 75% for three months, the appearance, morphology, size distribution, drug loading and in vitro release characteristics showed no significant change and the stability was satisfactory. The size analysis demonstrated that there was no obvious increase in the particle size of nanoparticles after conjugation. Immunological tests indicate highly selective binding of antibody-targeted nanospheres to C-erbB-2-overexpressing cells SK-BR-3.
Conclusion: The conjugation of mitoxantrone-loaded nanospheres and anti-C-erbB-2 monoclonal antibodies can keep the activity of anti-C-erbB-2 and increase the therapeutic efficacy of anti-mammary cancer drugs.