3.2.3 Serum Albumin
Serum albumin has also been tested as NPs for gene delivery. Mo et al. [88]
encapsulated the DNA into human serum albumin (HSA) by a desolvationcrosslinking method to produce DNA–HSA NPs having a mean size of 120 nm
and zeta potential of À44 mV. The DNA–HSA NPs were easily taken up by the
cells via receptor-mediated endocytosis that involved primarily caveolae pathways.
Within the cells, DNA–HSA NPs protected the DNA against nuclease attack and
showed sustained release of DNA over 6 days without significant cytotoxicity. The
overall transfection rate was found to be fivefold higher than obtained with
Lipofectamine.
3.2.4 Dendrimers
Dendrimers are polymeric molecules composed of multiple branched monomers
radially emanating from a central core. Dendrimers based on polymers such as
polyamidoamines (PAMAMs) and poly(propylene imine) can form compact
polycations under physiological conditions and, therefore, have been of interest to
researchers for use in gene delivery both in vivo and in vitro [78, 89, 90]. They can
also be functionalized with other molecules such as a-cyclodextrin [91], PEG [92],
etc. to enhance gene integration and expression. However, the use of dendrimers for
in vitro gene delivery into somatic and stem cells has not yet been demonstrated.
3.3 Composite NPs and Other NPs
Composite NPs such as calcium phosphate NPs have also gained interest for nonviral gene delivery. Cao et al. [93] used calcium phosphate (CP) nanocomposite
particles to encapsulate DNA for their delivery into MSCs. The CP–DNA NPs
(~100 nm) were reported to be less cytotoxic and more efficient in gene delivery
into MSCs than those of Lipofectamine or a standard calcium phosphate transfection kit.
4 Application of NPs in Stem Cells
NP-based gene delivery has plethora of applications in: (1) cellular reprogramming of somatic cells to derive induced pleuripotent stem (iPS) cells, (2) genetic
engineering for clinical application of stem cells, (3) creating a three-dimensional
(3D) in vitro niche for in vitro culture and/or directed differentiation of stem
cells, (4) tracking the transplanted stem cells in vivo and (5) investigation of gene
64
P. Pushp et al.
Serum albumin has also been tested as NPs for gene delivery. Mo et al. [88]
encapsulated the DNA into human serum albumin (HSA) by a desolvationcrosslinking method to produce DNA–HSA NPs having a mean size of 120 nm
and zeta potential of À44 mV. The DNA–HSA NPs were easily taken up by the
cells via receptor-mediated endocytosis that involved primarily caveolae pathways.
Within the cells, DNA–HSA NPs protected the DNA against nuclease attack and
showed sustained release of DNA over 6 days without significant cytotoxicity. The
overall transfection rate was found to be fivefold higher than obtained with
Lipofectamine.
3.2.4 Dendrimers
Dendrimers are polymeric molecules composed of multiple branched monomers
radially emanating from a central core. Dendrimers based on polymers such as
polyamidoamines (PAMAMs) and poly(propylene imine) can form compact
polycations under physiological conditions and, therefore, have been of interest to
researchers for use in gene delivery both in vivo and in vitro [78, 89, 90]. They can
also be functionalized with other molecules such as a-cyclodextrin [91], PEG [92],
etc. to enhance gene integration and expression. However, the use of dendrimers for
in vitro gene delivery into somatic and stem cells has not yet been demonstrated.
3.3 Composite NPs and Other NPs
Composite NPs such as calcium phosphate NPs have also gained interest for nonviral gene delivery. Cao et al. [93] used calcium phosphate (CP) nanocomposite
particles to encapsulate DNA for their delivery into MSCs. The CP–DNA NPs
(~100 nm) were reported to be less cytotoxic and more efficient in gene delivery
into MSCs than those of Lipofectamine or a standard calcium phosphate transfection kit.
4 Application of NPs in Stem Cells
NP-based gene delivery has plethora of applications in: (1) cellular reprogramming of somatic cells to derive induced pleuripotent stem (iPS) cells, (2) genetic
engineering for clinical application of stem cells, (3) creating a three-dimensional
(3D) in vitro niche for in vitro culture and/or directed differentiation of stem
cells, (4) tracking the transplanted stem cells in vivo and (5) investigation of gene
64
P. Pushp et al.