Self-Assembly of an Aptamer-Decorated, DNA–Protein Hybrid Nanogel: A Biocompatible Nanocarrier for Targeted Cancer Therapy

Nanocarrier-based chemotherapy is one of the most efficient approaches for the treatment of cancer, and hence, the design of new nanocarriers is very important. Herein, the design of a new class of physically cross-linked nanoparticles (nanogel) solely made of biomolecules including DNA, protein, and biotin as a nanocarrier for the targeted cancer therapy is reported. A specific molecular recognition interaction between biotin and streptavidin is explored for the cross-linking of a DNA nanostructure for the crafting of a nanogel. The most unique structural features of nanogels include the following: (i) excellent biocompatibility, (ii) decoration of the nanogel surface with biotin and streptavidin randomly that allowed the integration of aptamer DNA onto the surface of the nanostructure through the biotin–streptavidin interaction, (iii) high doxorubicin encapsulation efficacy through the intercalation of doxorubicin inside the DNA duplex, and (iv) stimuli responsiveness. The selective uptake of a doxorubicin-loaded nanogel by aptamer-receptor-positive cell lines (CCRF-CEM and HeLa) and its delivery inside the target cells are demonstrated. The selective uptake of the nanogel by CCRF-CEM and HeLa cells is attributed to the specific interaction between the aptamer DNA decorated on the surface of the nanogel with the PTK7 receptor overexpressed on CCRF-CEM and HeLa cell lines. These results imply that the nanogel obtained from the self-assembly of biomolecules would be ideal for the crafting of nanocarriers for targeted cargo delivery applications.