Topics in Current Chemistry (2020) 378:8
1 3
More recently, Fratoddi et al. [78] analyzed the effects of AuNPs functionalized
with 3-mercapto-1-propansulfonate (AuNPs-3MPS) and loading MTX topically
administered in vitro on a skin model and in vivo on an imiquimod-induced psoriasis-like mice model. The showed that treatment with this system was able to induce
a reduction in keratinocyte hyperproliferation, epidermal thickness and also the volume of inflammatory infiltrate in the in vivo model used. Hernández-Martínez et al.
[79] synthetized and evaluated a nanocomposite of AuNPs functionalized with calreticulin. Using in vitro and in vivo wound healing mice models of diabetes, they
assessed the ability of the nanocomposite to promote proliferation and migration.
Their results confirmed the utility of this bioconjugated plasmonic NPs (AuNPscalreticulin) as potential treatment for wound healing of diabetic ulcers.
In the case of AgNPs-based bioconjugates, Mandal and co-workers [80] fabricated a nanocomposite hydrogel comprised of in situ formed Ag nanowires
(AgNWs) deposited with chemically cross-linked carboxymethyl cellulose (CMC),
which demonstrated superior efficacy as a transdermal anticancer drug-curcumin
carrier. This plasmonic bioconjugate had the capacity to encapsulate both hydrophobic/hydrophilic transdermal drugs. In vitro experiments suggested that the presence
of AgNWs on cross-linked CMC enhanced both the penetration power of nanocomposite hydrogel and drug release in a sustained manner. Whilst ex vivo rat skin permeation analysis confirmed that drug delivery through the nanocomposite hydrogel
was permeable through the rat skin in controlled fashion, efficiently killing the MG
63 cancer cells.
Table 1 summarizes the bioconjugated plasmonic NPs cited in this review, indicating both the loaded active molecule and the potential application.
4 Conclusions
Bioconjugated plasmonic NPs are a promising approach for topical administration
of different cargos for several diseases. The excellent biocompatibility and readily adjustable physical and chemical features of plasmonic NPs are highly attractive options for purposefully designed nanomaterials aimed at biomedical applications. Several examples have been presented herein, illustrating the wide range of
cargoes and functionalization strategies that might be included when designing a
bioconjugated plasmonic NPs. Different physical and chemical parameters should
be taken into account when analyzing the effect of plasmonic NPs on human skin.
While chemical routes for obtaining on-demand plasmonic NPs are relatively wellestablished, and a large number of simple and reproducible experimental protocols
are available, the main frontier for mass usage is still a correct assessment of the toxicity of the NPs. Providing a relevant model for human skin, the experimental conditions for studying location and local concentration of plasmonic NPs differ greatly
from those found in synthesis laboratories. Therefore, this fruitful field of research
requires more efforts to fully understand the penetration mechanisms of these bioconjugated plasmonic NPs, enabling a decrease in associated toxicity and potential
long-term environmental impacts. In view of the latest contribution to the field, we
speculate that a reliable framework will be available in the short term, enabling a
230
Reprinted from the journal
1 3
More recently, Fratoddi et al. [78] analyzed the effects of AuNPs functionalized
with 3-mercapto-1-propansulfonate (AuNPs-3MPS) and loading MTX topically
administered in vitro on a skin model and in vivo on an imiquimod-induced psoriasis-like mice model. The showed that treatment with this system was able to induce
a reduction in keratinocyte hyperproliferation, epidermal thickness and also the volume of inflammatory infiltrate in the in vivo model used. Hernández-Martínez et al.
[79] synthetized and evaluated a nanocomposite of AuNPs functionalized with calreticulin. Using in vitro and in vivo wound healing mice models of diabetes, they
assessed the ability of the nanocomposite to promote proliferation and migration.
Their results confirmed the utility of this bioconjugated plasmonic NPs (AuNPscalreticulin) as potential treatment for wound healing of diabetic ulcers.
In the case of AgNPs-based bioconjugates, Mandal and co-workers [80] fabricated a nanocomposite hydrogel comprised of in situ formed Ag nanowires
(AgNWs) deposited with chemically cross-linked carboxymethyl cellulose (CMC),
which demonstrated superior efficacy as a transdermal anticancer drug-curcumin
carrier. This plasmonic bioconjugate had the capacity to encapsulate both hydrophobic/hydrophilic transdermal drugs. In vitro experiments suggested that the presence
of AgNWs on cross-linked CMC enhanced both the penetration power of nanocomposite hydrogel and drug release in a sustained manner. Whilst ex vivo rat skin permeation analysis confirmed that drug delivery through the nanocomposite hydrogel
was permeable through the rat skin in controlled fashion, efficiently killing the MG
63 cancer cells.
Table 1 summarizes the bioconjugated plasmonic NPs cited in this review, indicating both the loaded active molecule and the potential application.
4 Conclusions
Bioconjugated plasmonic NPs are a promising approach for topical administration
of different cargos for several diseases. The excellent biocompatibility and readily adjustable physical and chemical features of plasmonic NPs are highly attractive options for purposefully designed nanomaterials aimed at biomedical applications. Several examples have been presented herein, illustrating the wide range of
cargoes and functionalization strategies that might be included when designing a
bioconjugated plasmonic NPs. Different physical and chemical parameters should
be taken into account when analyzing the effect of plasmonic NPs on human skin.
While chemical routes for obtaining on-demand plasmonic NPs are relatively wellestablished, and a large number of simple and reproducible experimental protocols
are available, the main frontier for mass usage is still a correct assessment of the toxicity of the NPs. Providing a relevant model for human skin, the experimental conditions for studying location and local concentration of plasmonic NPs differ greatly
from those found in synthesis laboratories. Therefore, this fruitful field of research
requires more efforts to fully understand the penetration mechanisms of these bioconjugated plasmonic NPs, enabling a decrease in associated toxicity and potential
long-term environmental impacts. In view of the latest contribution to the field, we
speculate that a reliable framework will be available in the short term, enabling a
230
Reprinted from the journal