Page 604 - Book Hosokawa Nanoparticle Technology Handbook

APPLICATIONS 37 PINPOINT DRUG AND GENE DELIVERY

Calcein and Calcein capsulated Calcein-capsulated containing FIX expression gene only once to the tail
Bio-nanocapsule M-particle Bio-nanocapsule vein intravenously, expression of FIX was detected in
5 the blood of the mouse. This was a promising
expressed level that is expected to show a therapeutic
effect in patients with advanced hemophilia B.
In addition, although adenovirus vector is used in
4
ordinary gene treatment and excluded by immunity in
a few days, a few weeks of successive expression was
confirmed in the administration of BNC.
These results show that BNC has great potential
1 × 10 6 RFU tissues.
3
as a gene delivery system targeting liver cells and
2 (3) Retargeting of BNC
We attempted to deliver the altered BNC to tissues
other than liver (Fig. 37.3). Using epidermal growth
factor; EGF as a model, EGF-displaying BNC replac-
1 ing the liver cell binding site within the pre-S1 region
was prepared. The calcein was introduced into the cell
expressing EGF receptor on its cell surface A431 with
the calcein encapsulated EGF-displaying BNC but
0 was not introduced to the liver cell that had originally
HepG2 NuE WiDr HepG2 NuE WiDr HepG2 NuE WiDr been transfected [4].
By presenting various cytokines and antibodies on
the surface, many substances have been successfully
Figure 37.2 delivered with its specificity. Research on the single-
Pinpoint delivery of BNC encapsulated with calcein to the chain peptide, which enables high-level transfection
human liver cell. to tissue inside a living body is advancing and is
likely to widen the range of BNC application range.
In addition, by integrating the protein at the C termi-
intravenously from the tail vein. Fluorescence was nal of the HBsAg L protein forming the BNC, the
observed in the implanted human hepatoma – derived delivery of BNC containing protein in a living body
tumor tissue but not in internal organs or human colon succeeded.
cancer-derived tumor tissue in the mouse. Kupffer Therefore, responding to various targeting mecha-
cells in the liver usually phagocytize xenobiotics, nisms, BNC is expected to be the ultimate carrier to
however, BNC was not recognized as a xenobiotic. enable the pinpoint delivery of drugs, proteins and
Therefore, with low-molecular compounds, BNC
has great potential for drug delivery specific to the genes within a living body.
human liver cells and tissues.
2. Potential applications of BNC
(2) Gene delivery
Gene delivery by BNC was conduced by BNC with Example applications of BNC are shown below.
the expression vector for Aequorea coerulescens-
derived green fluorescence protein (GFP). BNC (1) Treatment for hepatic disease by BNC
encapsulated with GFP expressed gene was added to As the original target of BNC is human liver, it is a
the human normal liver cell and human hepatoma- natural flow to use BNC for the treatment of hepatic
deprived cell line by electroporation as described in disease.
the previous section, and fluorescence expressed by It is possible for BNC to deliver a treatment gene
GFP was observed. However, expression of GFP was (tumor suppressor gene, apoptosis-inducing gene,
not observed in the non-hepatoma cell line. In a etc.) to liver cancer, and more accurate targeting will
tumor-bearing mouse that had been implanted human be possible by presenting a molecule that recognizes
hepatoma-deprived cell line, GFP expression vector the antigen specific to the hepatic cancer cell
was delivered only in human hepatoma-derived solid selectively.
cancer. Expression of GFP was not observed in other Interferon is administered for the treatment of
tissues [4]. Hepatitis virus, but serious systemic side effects and
Therefore as a model of gene therapy, an experi- the production of neutralizing antibodies are major
ment to verify the treatment of hemophilia B with problems. Specifically administering interferon
blood clotting factor IX, FIX expression gene was genes or protein to liver using BNC may provide a
conducted. Consequently, by administering BNC safe treatment of Hepatitis virus.

576