Pluronic-Chitosan-Folate nano-micelles incorporated with quantum dots for anti-cancer drug therapy

<p>Background</p><p>Compared to traditional fluorescent molecules, quantum dots (QDs) have better luminous intensity and optical stability and is getting great attention in the field of bioimaging and nanoprobe technology/application. But its hydrophobic surface and strong cell toxicity limits its application.</p><p>Methods </p><p>Two kinds of QDs were used in this study for comparison, one is water-dispersed ZnO QD which was prepared by chemical sedimentation method, the other is commercialized water-soluble CdTe QD. The Pluronic nano-micelles containing QDs and anti-cancer drug were prepared. Then, the surface of Pluronic micelles containing QDs and anti-cancer drug were modified by folate-conjugated chitosan to obtain anti-cancer drug-loaded QD-Pluronic-Chitosan-folate nano-carriers. </p><p>Results</p><p>The particle size of ZnO prepared in this experiment is about 4.3 nm, which is larger than its theoretical Bohr radius (2.34 nm), but is closer to the size prepared by chenical synthesis method (2-4 nm). The size of commercized CdTe is 5.0 nm which falls under quantum size category; its theoretical Bohr radius is 5 nm. The particle size of micelles obtained after surface modification from 0.1% and 0.3 % chitosan is less than 100 nm, hence it can be used as tumor target drug delivery carrier. Based on the release profiles, it is evident that the release rate of Dox-loaded nano-micelles with surface modification by folate-chitosan is much slower than that without surface modification. Therefore, the binding affinity of Dox to the folate-chitosan conjugate is the primary factor influencing drug release response. The nano-micelle prepared in this experiment has good specificity to the cancer cell, able to increase the cytotoxic effect of drugs and reduces the side effects while improving the therapeutic effect. After 30 min of injection, nano-micelle reached the liver, lungs and abdominal cavity via blood circulation and with good luminous intensity.</p><p>Conclusions</p><p>Based on the results, the prepared drug-loaded QD nano-micelles could be successfully applied to the target therapy and bioimaging.</p>