平阳霉素磁性微球靶向治疗的实验研究

本研究用自制的一种新型平阳霉素磁性微球对人粘液表皮样癌裸鼠模型进行了治疗实验。实验结果表明，在外磁场作用下治疗效果明显好于游离平阳霉素。平阳霉素磁性微球提高了药物在局部的浓度，减轻了平阳霉素的毒副作用，延长了裸鼠的存活期

INHIBITORY EFFECTS OF TARGETING OF PINGYANGMYCIN ASSOCIATED MAGNETIC ALBUMIN MICROSPHERES ON MUCOEPIDERMOID CARCINOMA IN VITRO AND IN NUDE MICE

The inhibitory effects of pingyangmycin-bearing microspheres on mucoepidermoid carcinoma in vitro and in nude mice were studied and the distribution of microspheres in mice in the presence of a magnetic field was investigated.A new process of producing magnetic drug-bearing microspheres was developed. The heat-stabilited microspheres composed of a denatured human serum albumin matrix serve as the vehicle in which ultrafine particles of magnetite (Fe 3O 4) are entrapped.Because the microspheres contain the magnetic material,they are susceptible to the effects of magnetic field.Pingyangmycin (PYM) was linked covalently to the human serum albumin of the microspheres via a dextran (DEX) bridge. The efficiency of inhibition of PYM-bearing microspheres against MEC-1 cell line was similar to that of free PYM (P>0.05) and the microspheres may release PYM slowly.With the action of a magnetic field,the concentration of the microspheres at target site was five times more than that at non-target site.the PYM-bearing microspheres was significantly more effective in inhibition of the growth of mucoepidermoid carcinoma in nude mice than free PYM (P<0.01). The novel magnetic drug-bearing microspheres have the following characteristics:①PYM was avoided being heated so that its activity was not deteriorated.②Because one molecule of dextran can link many molecules of PYM,the ability of carring drug of the microspheres was greatly increased.③Drug-dextran conjugation possesses higher antitumor efficacy and lower toxicity than free drug,in addition,the conjugation shows increased staility in vivo.④The magnetic drug-bearing microspheres are easily processed and will be utilized extensively.