Ahmad S*
YMCA University of Science & Technology, India
*Corresponding author: Ahmad S, YMCA University of Science & Technology, Faridabad, Haryana, India
Submission: April 05, 2021;Published: May 20, 2021
ISSN: 2576-9170 Volume3 Issue3
Recent publications have very often emphasized that the human population with
unequal socioeconomic backgrounds do pollute the environment causing diverse human
health problems in general. The study also recommended for linking these inequalities
via the environment to the prevailing human health issues for finding out the pathways of
effective interventions. The glaring example of the adverse effect of this inequality can be
seen in human health care management und er the supervision of the WHO, in totality, before
initiating various health related programs to run and to be monitored subsequently Cushing
et al. [1].
Out of all human health related issues encountered globally, WHO could identify the area
of ‘Neglected Tropical Diseases (NTDs)’ that put a burden of 47.9 million disability-adjusted
life years throughout the World, particularly affecting the disadvantaged groups of people.
Realizing the criticality of NTDs in jeopardizing the overall sustainable development goals,
the WHO has been striving hard by making numerous positive efforts in this context as these
diseases continue to attract lower priority at the global level. It requires more intensive efforts
in implementing the well thought out action-plans by enhancing their priority first. This
requires not only for sustaining the commitment of the current agencies, but also engaging
the newer ones for paying more attention towards developing effective treatments of the
prevalent tool-deficient diseases Pastrana et al. [2].
According to the WHO, a list of 20 diseases, classified under NTD-category, are found
affecting >1 billion people in 149 countries. Most of the drugs used against these diseases are
rather old having several undesired side-effects. Noting lack of interest from the pharmaceutical
companies in developing more novel drugs or vaccines for NTDs manufactures, it is still worse
as the target population belongs to those countries with a serious affordability problem. In
this context of handling these deadly diseases, metal complexes have systematically been
studied to offer better treatments shown by numerous clinical studies carried out using their
unique physicochemical properties. It has also been noted that the metal complexes of arsenic,
mercury, bismuth, platinum, antimony, gold, iron, gadolinium, samarium, technetium, and
palladium, are certainly emerging as effective treatment strategies of these deadly diseases, as
reviewed recently. Undoubtedly, there is a dire need of discovering newer drugs using simpler
protocols scalable for commercial productions. Distributions of these drugs that are free from
drug resistance to the affected populations at affordable costs would be a necessary giant step
in this direction Ong et al. [3].
The success of metal-based complexes in treating these NTDs are now being presented
as the future medicine for NTDs, as they act via more than one biochemical-interaction
pathways to inhibit more than one target enzymes. For instance, a gold salt (e.g., ‘Auranofin’) is
worth mentioning as it is noted to suppress the inflammations via stimulating cell-mediated
immunity. WHO has authenticated this ‘Auranofin’ based treatment as it induces heme
oxygenase 1 (HO-1) mRNA with anti-inflammatory properties? ‘Auranofin’ has been found
effective in diseases like rheumatoid arthritis, leishmaniasis, and schistosomiasis Ong et al.
[3].
With the advances made in preparing nanomaterials for
biomedical applications with much better efficacies in treating a
large number of diseases during last few decades, the evolutions
of nanomedicines are currently advanced using reduced dimension
nanostructured material species of organic, inorganic, and
biomaterials nature. The enhanced physico-chemico-biological
features of these bio-medicinal nano formulations are finding
growing applications in targeted drug delivery, imaging and
theranostic applications in general. More recent developments of
two-dimensional (2D) lamellar materials are showing even better
promises in offering solutions appropriate for biomedicine. The
current developments of monoelemental material nanosheets
(NSs), called Xenes, are noted to offer smart features controlled by
external stimuli that are highly effective in theranostic applications
in nanomedicine. Theoretical and experimental investigations,
made so far, in case of Xene-NSs of borophene, silicene, germanene,
stanene, phosphorene, arsenene, antimonene, bismuthene, and
tellurene have reached a stage where a number of highly sensitive and
selective nano biosensors, and theranostic platforms are available
for targeted drug delivery, including simultaneous tracking of the
biochemical interaction pathways by advanced imaging techniques,
along with the desired drug release and excretion profiles during
their clinical trials. Xene-NSs are currently being investigated for
their practical applications in biosensors, bioimaging, therapeutic
delivery, and theranostics required in developing a smart platform
Ahmad [4-7]; Kumar [8] and Tao et al. [9].
A number of precautions are found mandatory to take into
account before developing such ‘Smart Drug Delivery Platforms’
involving significant advantages of better control of drug loading,
targeting, release, and excretion related to 2D-NMs in comparison
to traditional polymer-based drug delivery platforms. Possessing
larger specific surface areas providing more effective loading
of fluorescent dyes, targeting molecules and therapeutic drugs
as discussed by Zhang et al., involve many 2D-NMs exhibiting
capabilities of combined nano therapies. Such features were
confirmed in case of graphene quantum dots (G-QDs) loaded with
cisplatin (~ 50% at neutral conditions), exhibiting reduced toxicity
along with pH-dependent slow release. Cell experiments confirmed
their lower cytotoxicity, higher selective uptake rate and good
targeting capability features. The toxicity of targeted cisplatinloaded
nanocarriers against MDA-MB-231 cells was found higher
than non-targeted ones. Similarly, adding 2D-GO-nanopletlets in a
thermosensitive matrix produce a hybrid photothermally sensitive
nanogel exhibiting good stability Zhang et al. [10].
While exploring these advanced nanomedicines, one has to
keep in view the negative features of 2D-NMs as their enhanced
interactions with biological systems including tissues, organs,
cells and biomolecules, might cause acute and chronic toxicity.
The advantage of high drug-loading capacity of 2D-NMs could also
result in precipitate formations with serum proteins or red blood
cells after in vivo administration. Graphene nanosheets (G-NSs)
are known to cause side-effects affecting growth factor-β-related
signalling pathways and inducing apoptosis of mitogen-activated
protein kinases. G-NSs increase the intracellular ROS generation
and destroy the mitochondrial membrane, potential resulting
in cytotoxicity and its derivatives showing dose-dependent
haemolytic activity. Few layer thick graphene and high dose and
long exposure of GO-NSs might lead to mitochondrial dysfunction.
These observations do demand extra care in designing the smart
drug delivery and imaging platforms by taking care of the additional
side effects introduced along with their positive impacts Zhang et
al. [10].
Based on the brief background information described here,
it seems quite imperative to deploy 2D-NSs of metal species and
their functionalized derivatives for fabricating ‘Targeted Drug
Delivery and Imaging Platforms’ for treating a number of NTDs
already listed. It is worth noting that the metallicity of these
2D-NSs can be engineered using their unique physicochemical
properties derived from mono/multiple layered-NSs along with
their surface functionalized derivatives in a controlled manner.
Their colloidal suspensions in different liquid media as well as gel
preparations are indicated to offer stable formulations necessary
for Smart Drug Delivery and Imaging Platform. There are ample
number of successfully reported experimental results that confirm
the feasibility of this route in the near future. A somewhat similar
indications are from age-old experience of using metal species
based medicinal formulations in alternate system of ‘Unani’
and ‘Ayurvedic’ medicines of India to further corroborate these
speculations. Deploying lamellar 2D-NSs of metal species based
on improved formulations with significantly improved efficacies
would also be made to contain they are in-vivo toxicity at acceptable
level via several routes. Once, the physicochemical propertiesbased
Structure-Activity-Relationship (SAR) data is compiled,
in-silico models of drug-discovery would enable finding optimal
formulations via artificial intelligence and machine learning
techniques already in vogue for modern molecular medicines.
Taking into account the quantum effects associated with the mono/
multiple layered metal-NSs and their functionalized derivatives to
incorporate stimuli-responsive smart features will not be complete
without taking into account the spin-orbit coupling for realizing
topological insulators along with highly conducting surface and
edge states.
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