A simple synthetic route for the preparation of functional nanoscale graphene oxide (NGO), a novel nanocarrier for the loading and targeted delivery of anticancer drugs, is reported. The NGO is functionalized with sulfonic acid groups, which render it stable in physiological solution, followed by covalent binding of folic acid (FA) molecules to the NGO, thus allowing it to specifically target MCF-7 cells, human breast cancer cells with FA receptors. Furthermore, controlled loading of two anticancer drugs, doxorubicin (DOX) and camptothecin (CPT), onto the FA-conjugated NGO (FA-NGO) via pi-pi stacking and hydrophobic interactions is investigated. It is demonstrated that FA-NGO loaded with the two anticancer drugs shows specific targeting to MCF-7 cells, and remarkably high cytotoxicity compared to NGO loaded with either DOX or CPT only. Considering that the combined use of two or more drugs, a widely adopted clinical practice, often displays much better therapeutic efficacy than that of a single drug, the controlled loading and targeted delivery of mixed anticancer drugs using these graphene-based nanocarriers may find widespread application in biomedicine.

Loading and delivery of Bcl‐2‐targeted short interfering RNA (siRNA) and anticancer drug doxorubicin (DOX) by polyethylenimine (PEI)‐conjugated graphene oxide (PEI‐GO) is studied. A higher knockdown efficiency of siRNA delivered by PEI‐GO than by PEI is achieved. Sequential delivery of siRNA and DOX by the PEI‐GO nanocarrier shows a synergistic effect, which leads to significantly improved chemotherapy efficacy.

Single stranded ribonucleic acid (ssRNA) acts as a probe, antisense (AS), miRNA analog and inhibitor, and is promising for gene therapy and molecular diagnosis. However, free ssRNA exhibits poor cellular uptake due to its negative charges, and enzyme instability, which have largely limited the practical applications of ssRNA in biomedicine. To address these issues, we have developed a PEGylated reduced graphene oxide (PEG-RGO) nanovector for efficient delivery of ssRNA. We have demonstrated that PEG-RGO exhibits superior ssRNA loading and delivery capability, compared to the widely studied PEGylated graphene oxide (PEG-GO). Computational simulation further suggested that PEG-RGO binds ssRNA much stronger than PEG-GO, consistent with the experimental results. These results will have implications in designing RGO-based biocompatible and efficient ssRNA delivery systems.

Proteins of viral capsid may self-assemble into virus-like particles (VLPs) that can find many biomedical applications such as platform for drug delivery. In this paper, we describe preparation of VLPs by self-assembly of VP6, a rotavirus capsid protein that was chemically conjugated with doxorubicin (DOX), an anticancer drug. VP6 was first highly expressed in E. Coli, followed by purification and renaturation. DOX was then covalently attached to VP6 to form DOX-VP6 (DVP6) conjugates, which were subsequently self-assembled into VLPs under appropriate condition. Next, lactobionic acid (LA) was chemically linked to the surface of the VLPs. We demonstrated that the aforementioned nanosystem shows specific targeting to hepatoma cell line HepG2. The chemically functionalized VLPs, a kind of biological nanoparticles with excellent biocompatibility and biodegradability, can be prepared in large scale from E. Coli through our method, which may find practical applications in biomedicine.