Biomedical Engineering Reference
In-Depth Information
mediate high levels of gene expression into hMSCs.
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By polyplexing with
PEI, the cell-uptake ability of the nanoparticles was enhanced for both in vitro
and in vivo culture systems, so that transfection efficiency into hMSCs was
enhanced.
Wang et al. designed and manufactured a bioactive construct of poly(lac-
tide-co-glycolide) (PLGA), fibrin gel, bone marrow mesenchymal stem cells
(BMSCs), and N,N,N-trimethylchitosan chloride (TMC)/pDNA encoding
transforming growth factor-b1 (pDNA-TGF-b1) for osteochondral restora-
tion, whose biological performance was evaluated in a rabbit model.
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The
TMC/DNA complexes had a transfection efficiency of 9% to BMSCs and
showed TGF-b1 expression in vitro. In vivo culture of the composite constructs
was performed by implantation into full-thickness cartilage defects of rabbit
joints. After implantation for 12 weeks, the cartilage defects were successfully
repaired by the composite constructs of the experimental group, and the neo-
cartilage integrated well with its surrounding tissue and subchondral bone.
To enhance the level and prolong the duration of gene expression for gene-
engineered rat mesenchymal stem cells (MSCs) using a nonviral vector, He
et al. developed a novel transfection system based on the reverse transfection
method and 3D scaffold.
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Collagen sponge and poly(ethylene terephthalate)
nonwoven fabric were introduced as scaffolds to perform 3D culture with
reverse transfection. pDNA coding transforming growth factor b-1 (TGFb-1)
was delivered to MSCs to assess its ability in inducing chondrogenesis with the
3D nonviral reverse transfection system. The electric charge of the anionic
gelatin played an important role in this system by affecting the release pattern
of the gene complexes and through the adsorption of serum protein to the
substrate. Also, the 3D scaffold provided a good environment for cell
proliferation and showed enhanced gene expression compared with the 2D
system. Therefore, TGFb-1 gene-engineered MSCs using a nonviral vector and
the 3D reverse transfection system are promising in the treatment of cartilage-
related disease.
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4.7.2 Combinatorial Vectors
Gene vectors with different structures, properties, and transfection mechan-
isms could be combined together to obtain multifunctional combinatorial
vectors. For example, viral vectors can combine with nonviral vectors, and
polymeric vectors can conjugate with inorganic nanoparticles. Adenoviral
vectors offer many advantages for cancer gene therapy, including high
transduction efficiency, but safety concerns related to severe immunogenicity
and other side effects have led to careful reconsideration of their use in human
clinical trials. To overcome these issues, a strategy of generating hybrid vectors
that combine viral and nonviral elements as more intelligent gene carriers has
been employed. Kim et al. coated an adenovirus (Ad) with an arginine-grafted
bioreducible
(Figure 4.13).
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polymer
(ABP)
via
electrostatic
interaction
Enhanced
transduction
efficiency
was
observed
in
cells
treated
with
the
