Biomedical Engineering Reference
In-Depth Information
transfer of the adhering cells (Wang, Oyane, et al. 2011). In contrast, nano-
hydroxyapatite acted as a gene-activated matrix (GAM) for BMP2 delivery
conjugated with bioactive and biodegradable collagen (Curtin et al. 2012).
To decrease the toxicity of polymeric gene carriers, strategies of PEGylation
and complexes formed via nonelectrostatic interactions, and such hydrogen
bonding was proposed to combine medication with HAp using high hydro-
static pressurization technology (Kimura et al. 2011).
On the strength of these mechanism studies, CaP-based hybrid materials are
qualified vectors
in vitro
and
in vivo
. Various cell lines such as human embry-
onic kidney 293 cell (Tang et al. 2012), C3H10T1/2 cells (Luong et al. 2009),
human umbilical vein endothelial cell (Zohra et al. 2009), and COS-7 cells
(Kimura et al. 2011) have been coverage initiated. Also, ectopic bone formation
(Wang, Oyane, et al. 2011) and stem cell-mediated bone formation (Curtin et al.
2012) exhibited a promising gene delivery system for bone regeneration.
7.3.2 Hybrid Materials Integrated with Gold
Nanoparticles (GNPs) for Gene Delivery
Gold nanoparticles (GNPs) have gained particular interest for widespread
use as delivery platforms because of their advantageous characteristics that
are easily surface functionalized with chemical and biological molecules,
photothermal properties, and apparently low toxicity. One of the most
promising applications is for gene delivery and transfection as a functioned
vector. Moreover, modified with organic molecules containing thiols, phos-
phates, and amines make their application more efficient.
Various organic materials including peptides, cationic polymers, and cat-
ionic lipids have been extensively investigated as gene delivery vehicles.
Among them, PEI has been widely exploited to form polyelectrolyte com-
plexes with nucleic acid, and its excellent performance is becoming the
standard for polymer-mediated gene delivery by reducing enzymatic deg-
radation, enhancing cellular uptake, and endosome escape. Song et al. (2010)
have conjugated PEI-capped AuNPs to siRNA targeting endogenous cell-
cycle kinase displaying significant gene silence and enhanced cell apoptosis.
The influence of particle size on cell transfection was investigated by two
sets of PEI-coated Au NPs having particle size about 6 nm (<10 nm Au-PEI
NPs) or 70 nm (<100 nm Au-PEI NPs), respectively (Cebrián et al. 2011). The
smaller Au-PEI NPs led to higher efficiency owing to their lower agglom-
eration state inside cells and quicker endosomal escape of DNA. However,
4 and 100 nm AuNPs showed similar biological effects
in vivo
by applying
PEG-coated AuNPs as vector (Cho et al. 2009). In order to offer support for
potential further clinical application, PEI-conjugated gold nanoparticles
were applied to corneal tissues exhibiting appreciable gold uptake and mod-
erate toxicity (Sharma et al. 2011).
Target-specific hybrid material is regarded as one of the most important
platforms for the development of gene delivery. Hyaluronic acid (HAp) as a
Search WWH ::
Custom Search