Biomedical Engineering Reference
In-Depth Information
(a)
(b)
(c)
(d)
(e)
(f )
FIGURE 7.9
SEM of scaffold surface. (a) Pure chitosan/collagen scaffold, (b) the scaffolds with pEGFP-
TGF-β1, (c) the scaffolds with AdTgf-β1, (d) HPLCs on pure chitosan/collagen scaffold after 2
days culture
in vitro
, (e) HPLCs on the scaffolds with pEGFP-TGF-β1 after 2 days culture
in vitro
,
and (f) HPLCs on the scaffolds with AdTgf-β1 after 2 days culture
in vitro
.
The surface functionalization of silicate nanoparticle has been popular
with an integrated organic molecule to expose amino groups. A kind of new
self-assembled amino-modified silica nanoparticle was established with a
diameter of 20 to 30 nm and positive surface charges of +11.3 mV (Xiao et al.
2009). Xiao et al. (2009) found that amino-modified silica nanoparticles could
tightly bind with plasmid DNA, and the resulting nanoconjugate could
transfer DNA to cells efficiently
in vitro
and
in vivo
, indicating the poten-
tial of gene therapy for hepatocellular carcinoma. The conjugated organics
have also been modified to adapt to the strict environmental requirement.
Chitosan is an N-deacetylation product of chitin, and it has been proved to
be biologically renewable, biodegradable, biocompatible, nonantigenic, non-
toxic, and biofunctional (Figure 7.9) (Zhang et al. 2006). Concerning its solu-
bility limitations in a fluid environment, quaternized chitosan hybrid with
rectorite exhibited better transfection efficiency (Wang et al. 2008).
For pursuing higher efficiency, the targeted gene delivery was explored
tentatively. It is well known that mannose receptors are abundantly
expressed on antigen presenting cells (APCs) such as macrophages (Singodia
et al. 2012). In this regard, mannosylated polyethylenimine coupled mesopo-
rous silica nanoparticles targeted macrophage cells with mannose receptors
selectively and enhanced transfection efficiency (Park et al. 2008). Similarly,
peptide-targeted mesoporous silica nanoparticle was fabricated to delivery
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