Encapsulating Materials within VNPs - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 128

polymers as artificial cargo (Ren ., 2006). Attempts to encapsulate

neutral molecules such as fluorescein-labeled dextran failed, demonstrating
that encapsulation is based on electrostatic interactions between the
negatively charged polymers and the positively charged interior of the
capsid proteins (Ren

et al

., 2006).
In a follow-up study, the concept of encapsulating foreign polymers was
exploited to encapsulate a complex of PSA and the cytotoxic drug doxorubicin.
The positively charged drug was mixed with PSA and the resulting PSA-

et al

Figure 5.3 Schematic illustration of the preparation of doxorubicin-loaded HCSRV

viral protein cage without (PC-Dox) and with folic acid conjugation (fPC-Dox).
Steps A1 and B2 are indicative of the removal of viral RNA from the plant virus
and purification of coat proteins. Steps A2 and B3 involve the encapsulation of
polyacid and doxorubicin during the re-assembly of protein cage. Step B1 refers to
the conjugation of folic acid onto the viral protein coat. Reproduced with permission
from Ren, Y., Wong, S. M., and Lim, L. Y. (2007) Folic acid-conjugated protein cages
of a plant virus: a novel delivery platform for doxorubicin, Bioconjug. Chem. , 18 (3),

836-843.