Polymeric nanoparticles that can stably load anticancer drugs and release them in response to a specific trigger such as glutathione are of great interest in cancer therapy. In the present study, dendrimer-encapsulated gold nanoparticles (DEGNPs) were synthesized and used as carriers of thiolated anticancer drugs. Thiol-containing drugs such as captopril and 6-mercaptopurine loaded within DEGNPs showed an "Off−On" release behavior in the presence of thiol-reducing agents such as glutathione and dithiothreitol. Thiolated doxorubicin and cisplatin, loaded within the nanoparticle, showed much reduced cytotoxicity as compared to the free anticancer compounds. The toxicity of drug-loaded DEGNPs can be enhanced by improving the intracellular glutathione. Glutathione-triggered release of thiolated doxorubicin within cancer cells is further confirmed by flow cytometry and confocal laser scan microscopy studies. In addition, DEGNPs showed excellent biocompatibility on several cell lines. This study provides a new insight into biomedical applications of dendrimers and dendrimer-encapsulated nanoparticles.

No abstract

No abstract

No abstract

In this study, G5 PAMAM dendrimer and α-, β-, γ-cyclodextrin (CD) conjugates were synthesized. Host-guest behaviors of the conjugates toward five guest molecules including sodium methotrexate (MTX), amantadine hydrochloride (ADH), sulfamethoxazole (SMZ), sodium deoxycholate (SDC), and sodium dodecyl sulfate (SDS) were analyzed by NOE NMR techniques. Among the five guest molecules, ADH only binds with β-CD in G5-β-CD, SDC shows higher priority to localize within the cavity of γ-CD in G5-γ-CD, while MTX exhibits selective encapsulation within the cavities of G5 dendrimer in G5-α-CD. SDS has high binding affinity with α-CD in G5-α-CD but forms a precipitate in the complex solution. SMZ shows simultaneous encapsulation within CDs (α-, β-, and γ-CD) or G5 in the presence of the three conjugates. The host behavior of G5-CD conjugates depends on CD cavity size, guest size, and hydrophobicity. The results obtained in this study are helpful in the optimization of dendrimer-CD conjugate-based drug delivery systems.