Research About Hollow Spherical HAP And Cancer Diagnosis And Treatment Drug

Hydroxyapatite (HAP) is a kind of carrier with good biocompatibility. Controlling its structure and size makes it get a high drug-loading, good release effect and passively targeted performance, which reducing toxic effects of traditional anti-cancer diagnosis and drugs by decreasing the drug dose.HAP particles of different particle size range with the hollow spherical structure were prepared by PO43- source and CaCO3 template. The V-CaCO3 template with controllable particle size (500-1000nm) was synthesized under the mild conditions with Ethylene glycol (EG)/water as the medium, Ca(CHCOO)2 and NaHCO3 as raw material. Then the hollow spherical HAP (HHA) with a surface area of 190m2/g was obtained through the reactivity between PO43" source and V-CaCO3. The shell thickness of HHA was depends on the amount of PO43- source. In the process of removing cores,1:500 acetic acid was necessary, it is ensure that the hollow ellipsoid shell is not destroyed when the concentration of acetic acid solution as low as possible. Changing CaCO3 template, it can also be successfully to prepare nano hollow spherical HAP (NHHA) through calcite CaCO3 with the particle size of about 50 nm.Research the loading performance of HHA taking tumor early diagnosis imaging contrast (Gd-DTPA) as the model. The results showed that the drug-loading of HHA was improved with Gd-DTPA concentration increases. The results of vitro release indicated that the release rate of Gd-DTPA can be slowed down after loaded by HHA, and the outer coating layer (sodium alginate, SA) not only be able to reduce the leakage of Gd-DTPA in the coating process, but also to avoid the burst release of Gd-DTPA from Gd-DTPA-HHA system.Study the loading performance of NHHA taking antitumor drugs doxorubicin (DOX) as the model. The results showed that the higher the concentration of DOX, the encapsulation efficiency and drug-loading of HAP higher. The vitro release studies showed that the the drug release rate was slow down significantly when the NHHA was coated by an outer layer of natural polymer carboxymethyl chitosan (CMCH). Evaluate the inhibition ratio of NHHA, DOX, CMCH and compounds to lung tumor cells (Bel-7402 assay) through MTT method. The results indicated that the synergy system of DOX-NHHA@CMCH have a better inhibitory effect than DOX to Bel-7402 tumor cells.