gel layer as inner shell, and a subsequent thin hydrophilic nonlinear PEG-based gel
layer as outer shell. The cell viability evaluation in mouse melanoma cells
(B16F10) demonstrated that curcumin-loaded hybrid nanogels maintain the high
anticancer potential of curcumin, resulting in 80–90% of cancer cell death. In the
hybrid nanogel system, the Ag/Au core NPs emit strong fluorescence for imaging
and also exhibit strong absorption in the near-infrared (NIR) region for
photothermal conversion. The inner polystyrene gel layer is introduced to provide
strong hydrophobic interactions with curcumin for high drug loading yields,
whereas the external nontoxic and thermoresponsive PEG analog gel layer is
designed to trigger release of the pre-loaded curcumin, either by variation of
surrounding temperature or by exogenous irradiation with NIR light. The
curcumin-loaded hybrid nanogels exhibit potent cytotoxicity against B16F10 cells
by combined chemo- and photothermal treatment, thus providing higher therapeutic
efficacy than chemo- and photothermal treatments alone or their additive efficacy
[146]. Sabitha et al. developed biodegradable pH-sensitive chitin nanogels loaded
with curcumin (CCNGs) and used them for the transdermal delivery of curcumin to
melanoma. They reported that the CCNGs possess excellent skin penetration and
retention properties. Due to their efficiency of skin penetration, these nanogels
would be a novel approach for trafficking of curcumin through the different layers
of skin (Fig. 6); they also showed selective toxicity towards melanoma cell lines
A375 [147].
Table 1 shows different polymers used as nanocarriers for curcumin and the
cancer cell lines that are affected by the formulations. The nanoencapsulation of
curcumin within polymeric nanoparticles improves its therapeutic effect by
overcoming the problems of low aqueous solubility and poor bioavailability. Due
to its better therapeutic potential, nanocurcumin could be effectively used as a
modality for cancer treatment.
4.2 Epigallocatechin-3-gallate
The potential health benefits of tea consumption are attributed to the sensitive
water-soluble nutraceutical compound EGCG. But, EGCG faces the issue of instability in neutral and alkaline pH and fast degradation with oxygen, temperature, and
pH changes [148]. This necessitates a suitable vehicle for the controlled release of
EGCG, thereby enabling it to carry out its therapeutic activities.
The possibility of using thermally modified b-lactoglobulin to form coassembled nanovehicles (50 nm) for the protected delivery of EGCG against
oxidation and degradation has been studied [149]. The study suggested that the
approach could be used for encapsulating important polyphenolic nutraceutical
compounds and could be used as a preventive medicine. Shao et al. [150] reported
electrospinning of the biodegradable polymer PCL with multi-walled carbon
nanotubes (MWCNTs) and green tea polyphenol (GTP), as a model drug resulting
in the formation of nanofiber meshes. This process imparted controlled release
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S. Maya et al.
layer as outer shell. The cell viability evaluation in mouse melanoma cells
(B16F10) demonstrated that curcumin-loaded hybrid nanogels maintain the high
anticancer potential of curcumin, resulting in 80–90% of cancer cell death. In the
hybrid nanogel system, the Ag/Au core NPs emit strong fluorescence for imaging
and also exhibit strong absorption in the near-infrared (NIR) region for
photothermal conversion. The inner polystyrene gel layer is introduced to provide
strong hydrophobic interactions with curcumin for high drug loading yields,
whereas the external nontoxic and thermoresponsive PEG analog gel layer is
designed to trigger release of the pre-loaded curcumin, either by variation of
surrounding temperature or by exogenous irradiation with NIR light. The
curcumin-loaded hybrid nanogels exhibit potent cytotoxicity against B16F10 cells
by combined chemo- and photothermal treatment, thus providing higher therapeutic
efficacy than chemo- and photothermal treatments alone or their additive efficacy
[146]. Sabitha et al. developed biodegradable pH-sensitive chitin nanogels loaded
with curcumin (CCNGs) and used them for the transdermal delivery of curcumin to
melanoma. They reported that the CCNGs possess excellent skin penetration and
retention properties. Due to their efficiency of skin penetration, these nanogels
would be a novel approach for trafficking of curcumin through the different layers
of skin (Fig. 6); they also showed selective toxicity towards melanoma cell lines
A375 [147].
Table 1 shows different polymers used as nanocarriers for curcumin and the
cancer cell lines that are affected by the formulations. The nanoencapsulation of
curcumin within polymeric nanoparticles improves its therapeutic effect by
overcoming the problems of low aqueous solubility and poor bioavailability. Due
to its better therapeutic potential, nanocurcumin could be effectively used as a
modality for cancer treatment.
4.2 Epigallocatechin-3-gallate
The potential health benefits of tea consumption are attributed to the sensitive
water-soluble nutraceutical compound EGCG. But, EGCG faces the issue of instability in neutral and alkaline pH and fast degradation with oxygen, temperature, and
pH changes [148]. This necessitates a suitable vehicle for the controlled release of
EGCG, thereby enabling it to carry out its therapeutic activities.
The possibility of using thermally modified b-lactoglobulin to form coassembled nanovehicles (50 nm) for the protected delivery of EGCG against
oxidation and degradation has been studied [149]. The study suggested that the
approach could be used for encapsulating important polyphenolic nutraceutical
compounds and could be used as a preventive medicine. Shao et al. [150] reported
electrospinning of the biodegradable polymer PCL with multi-walled carbon
nanotubes (MWCNTs) and green tea polyphenol (GTP), as a model drug resulting
in the formation of nanofiber meshes. This process imparted controlled release
222
S. Maya et al.