Biomedical Engineering Reference
In-Depth Information
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Figure 12.2
The transfection efficiency of nonviral vectors using different transfection
methods: (A) PEI; (B) spermine-pullulan. For the reverse transfection,
the reverse gene transfection system was composed of anionic gelatin,
Pronectin, and gene complexes, all of which were coated on the surface of
culture substrate before the introduction of the MSCs. The level of gene
expression was compared with that of cells transfected in the medium
containing the gene complexes (conventional transfection method) either
in the presence or absence of serum.
and the sensitivity of the carriers to gene uptake, as well as the condition of
carriers in the serum.
32
Up to now, the reverse transfection approach, which is
different from the conventional approach, has been demonstrated to be able to
protect the carriers from the inhibiting effects of the serum. In our studies, it
was shown that using the reverse method, a high transfection efficiency of
MSCs was observed even in the presence of serum. For the conventional
method, in which the complex is added to the culture medium, the presence of
serum reduced the transfection level to 25 ¡ 1.5% and 1.25 ¡ 0.5% using PEI
and spermine-pullulan as the vectors, respectively (Figure 12.2). Also, the
reverse method employing biodegradable or nonbiodegradable 3D scaffolds
has been reported.
31,36,37
12.3
MSCs as a Promising Targeted-Delivery Vehicle
in Cancer Gene Therapy
12.3.1 Rationale for Using MSCs as a Vehicle for Gene Delivery
In 1987, Friedenstein et al.
38
found that the bone marrow single-cell can
differentiate into bone and cartilage-forming adipocyte cells under certain
conditions. These cells retain the ability of forming bone and cartilage after
being transplanted in diffusion chambers after 20-30 cell doublings in vitro,
and were called mesenchymal stem cells (MSCs) or bone marrow stromal cells.
MSCs could also be isolated from other tissues, such as adipose tissue
39
and
placenta.
40
It was reported
38
that human MSCs derived from adult marrow
had been thought to be multipotent cells, which have the potential to
differentiate to lineages of mesenchymal tissues, including bone, cartilage, fat,
tendon, muscle, and marrow stroma. Stem cells, which have the characteristics
of human MSCs, were isolated from marrow aspirates of volunteer donors. It
