Preparation Of PYM Gelatin Microspheres And Related Experimental Studies On Biological Characteristics

The incidence of head and neck tumors is about 5% of the total rate of tumors in our country. It is for a long time that the therapy of the head and neck tumors maily depenes on the surgery operations. The blood supply of oral and maxilliofcial part is flourish and the anatomic stucture is complicated, so the conventional surgery has some problems such as high risk,heavy trauma,high relapse rate.et al. Besides the features deformation after operations and malfunction has badly affects on patients life value.Transcatheter Arterial Embolization(TCAE) offers a new approach for therapy of the oral and maxillofacial malignant tumors. TCAE has many advantages including good targeting,high therapeautic effects and light trauma.Now TCAE has become a main part of the tumors' complex therapy and been put more and more attentions on.In the past years embolizations and chemotherapy have been combined to treat the malignant tumors.A few articles reported embolic agents enraping-5-chemopeautic medicine is applied to the lingual carcinoma.A successful application of TCAE must have three elements:good embolic agents, strict indications and proficient catheter manipulation.But now there is still no optimic embolic agents that can be successfully used clinically.In order to improve the effect of chemoemoblization therapy.this study aims to prepare a new kind agent of microsperes-Pingyangmycin gelatin microspheres(PYM-GMS) for the interventional chemoemoblization therapy. In this study we apply gelatin to enwrap PYM.the most useful chemotherapy medicine by improved emulsified cold-condensation method.In order to test the biological characteristics and embolizational effect of PYM-GMS we did some related experiments.This study is divided into three parts: 1. Preparation of a sustained-release PYM-GMS for use of chemoembolization therapy, 2. Physical, chemical and biological characteristics examinations, 3. Experimental study on drug release characteristics in vivo. 1. Preparation of a sustained-release PYM-GMS for use of chemoembolization therapyOn the basis of gelatin's self-crosslinking and its solidification by aldehyde, PYM-GMS were prepared. The PYM-GMS which enwrap pingyangmycin , is spheral with glossy surface,and is stable with good fluidity when stored in refrigerator or at room temprature. The roundness of PYM-GMS is 1.02 ?0.005,The mean diametre is 85.6 ji m, 78 % of them ranging from 50 ~ 200 M m, which fit the use of embolization. 2. Physical, chemical and biological characteristics examinations-6-To study physical, chemical and biological characteristics of PYM-GMS then we can estimate its value. Through uv-spectrophotometer drug content and encapsulation rate was measured, they were 6.8% and 91.3% respectively. The characteristics of drug release was in vitro tested byHigh performance liquid chromogram. 70% of the drug was released in 3 hours in the simulated environment in vivo and total drug was released for more than 6 hours. So PYM-GMS prepared by this method were stable and the velocity of gelatin decomposition and drug release were proper for clinical use. The sterilization of PYM-GMS was processed and they were proved to be of asepsis. 3. Experimental study on drug release characteristics in vivoStudies were conducted in rabbits to evaluate the release characteristics of PYM gelatin microsphere(PYM-GMS) by the analysis of different employment methods of PYM. PYM-GMS was perfused into the external carotid artery of rabbits by selective artery embolization under the supervision of X-ray, PYM solution was infused into the external carotid artery and femoral vein as control, blood samples were tested at different time and analyzed statistically. The embolized tissue was investigated histologically. Results: A transient higher blood drug concentration(BDC) was produced by artery perfusion. BDC was kept a longer time by vein drop, while there was no significant difference between circulating and local drug concentration. Small dosage of PYM-GMS by method of artery embolization could produ...