Key words
Nanomedicines - Nanotechnology - Bioavailability - Drug Delivery - Toxicity - Nanomaterials
Introduction
Nanoparticles as drug delivery structures are being increasingly used to improve
therapeutic efficacy and patient response to medication by turning them into
advanced systems of therapeutic and diagnostic drugs by manipulating their size,
surface properties, dosage, and reduced side effects. Linking the idea of a drug
working as a “magic bullet” by Paul Ehrlich proposed centuries ago,
tremendous progression have been made in this arena to widen the scope for targeted
delivery of drugs since then, that could selectively eliminate diseased cells
without damaging the neighbouring normal cells [1]
[2]
[3]. Targeted nano drug delivery using
nanocarriers is one such concept that can transfer drugs at the location because of
their altered features with enhanced capability to transmit beneficial molecules of
drugs at the desired location more effectively. The nano-carrier and the drug
molecule organized together with each other encapsulating or adsorbing the drug on
its surface, and then binding to a cell surface-specific receptor thereby achieving
targeted delivery of drugs in a cell- or tissue-specific manner is an effective way
of drug development medicinal chemistry today. The review centres on the
integration, appropriate features for effective minute particulate assisted drug
administration and their forms as well and the different uses in which these
nano-particulate structure have shown possibility. To sum up, we have discussed the
tremendous possibilities of rising novel particle approach in field of
pharmaceutical sector.
Target nanocarrier molecules offer the benefits like shielding the molecule from
untimely metabolic breakdown, increase infiltration of the drug into the cell,
regulate pharmacokinetic, pharmacodynamic properties, drug distribution and augment
absorption of the drug molecule in the targeted organ etc. They upsurge
bioavailability, shield and alleviate more subtle agents, curtail side effects, and
offer resources for active targeting. It enables delivery less water-soluble drugs
and can provide means of bypassing the liver, thereby preventing the first pass
metabolism. The hydrophobic drugs may also be encapsulated inside the central space
of the nanocarriers and delivered at the site effectively. They offer to regulate
physicochemical properties of the drug molecule and can control the rate at which a
drug is made available in the body where it is released by increasing the properties
like stability, water solubility of drugs, prolong the cycle time, increase the
uptake rate of target cells or tissues, and reduce enzyme degradation, expand impact
and effectiveness of drugs [4]
[5].
The drug delivery system not only has an objective of delivery therapeutics to the
target diseased part of body in controlled manner but also to maintain the drug
level in the body. Recently, nano level technique has found its means of
revolutionizing science and has a range of applications in biomolecular detection
and diagnostics, therapeutics, catalysis, thermionics, genetic analysis, oculus,
electro optical, medicaments, light, and scavengers and many more. Nanotechnology
applications in drug delivery is a key research area for the pharmaceutical and
biotechnology industries in the future, due to its unique ability to tackle the
shortcomings and downsides of conventional medications [6].
Nanomaterials are being used as drug delivery systems as they are supramolecular
structures made up of polymers with exceptionally small size varying from
10 nm to<1000 nm and greater surface area to volume
proportion and highly stable too, there are various categories of nanomaterials as
shown in [Table 1]. They are pH- labile
chemically steady structures that can be constructed with different biochemical way
that are eco-friendly and economical [7]
[8]. These are significantly utilized in
remedial and diagnostic treatment along with the development of drug delivery
playing an essential field in the nanotechnology.
Table 1 Different Types of Nanomaterials used in drug delivery
[7].
|
S. No.
|
Types
|
Examples
|
|
1
|
Inorganic-based nanomaterials
|
Different metal and metal oxide nanomaterials like silver (Ag),
gold (Au), aluminum (Al), cadmium (Cd), copper (Cu), iron (Fe),
zinc (Zn), and lead (Pb) nanomaterials, whereas examples of
metal oxide-based inorganic nanomaterials are zinc oxide (ZnO),
copper oxide (CuO), magnesium aluminum oxide
(MgAl2O4), titanium dioxide
(TiO2), cerium oxide (CeO2), iron
oxide (Fe2O3), silica (SiO2),
and iron oxide (Fe3O4), etc.
|
|
2
|
Organic based nanomaterials
|
Organic-based nanomaterials are formed from organic materials
excluding carbon materials like dendrimers, cyclodextrin,
liposome, and micelle.
|
|
3
|
Carbon-based nanomaterials
|
Graphene, fullerene, single-walled carbon nanotube, multiwalled
carbon nanotube, carbon fiber, an activated carbon, and carbon
black,
|
|
4
|
Composite-based nanomaterials
|
Combination of metal-based, metal oxide-based, carbon-based,
and/or organic-based nanomaterials, and these
nanomaterials have complicated structures like a metal-organic
framework like Chitosan nHA and nano-silver particles (nAg),
Alginate Nano-silica (nSiO2)
|
The dimension of the nano-carrier plays significant role in drug delivery systems.
Suitable appropriate size and large surface area of the nanoparticles shows rise in
solubility. Hence, enhances the ability of nano-carrier to cross the blood brain
barrier (BBB) and get absorbed through the solid junction of endothelial cells of
the skin after entering the pulmonary system [9]. Traditional drugs which are taken orally or via injection are not
always produced as the most favourable formulation for each product. A product needs
more advance and novel approach like targeted drug delivery to enhance the efficacy.
The basic functions of the nanoparticles are to have enough concentration of drug in
targeted sites and to decrease the side effects by controlling the pharmacokinetics
of the drug. These have gained popularity because they offer controlled drug release
at a single dose. In addition, with help of adaptation, the nanosystem could inhibit
the endogenous enzymes from degrading the compound [10].
Basics of Nanotechnology based techniques in designing nanomaterial
Basics of Nanotechnology based techniques in designing nanomaterial
Nanotechnology is the science that forms the basis of utilization of nanomedicines in
prevention and curing different diseases by means of suitable nanoparticles and
nanobots which are utilized in a wide range of applications including diagnosis,
drug delivery, and activating targets in a living system [11]
[12]
[13]. The past decade studies
interpreted that the biological response and nano interaction significantly plays an
important role in designing the nanoparticles for effective drug delivery. Poorly
soluble drugs have different biopharmaceutical concerns such as less diffusion
capacity, enough for intravenous intake, and adverse effects. The limitations of
such drugs can be overcome by developing nano-materials in drug delivery systems
[14]
[15].
The designing of nanoparticles for drug delivery has been widely studied to possess
several advantages like drug solubility, drug release, diffusivity, and eliciting
immune response [16]. It can also lead to the
enhancement and advancement of efficient directive routes, decrease virulence
factor, less side effects, proper targeted drug delivery with better distribution
and increased biotransformation of drug as shown in the [Fig 1]. The designed drug delivery mechanisms
are targeted to the specific receptor sites or carry the moderate release of the
therapeutic compounds to the specific sites [17]. This requires the ability to overcome the resistance such as
opsonisation by the macrophage system. Two approaches by which nanoparticles
transports drugs are passive and self-delivery. In passive delivery the
incorporation of the drugs into hollow space of the nanostructure by means of
water-resistant effect which further plays an important role in drug release to
target sites due to the low consistency of medicament present in hydrophobic region.
Similarly, self -delivery shows that delivery of the drug imported on the
nanocarrier to target location. The duration of drug release plays critical role as
the drug can dissociate anytime from carrier leading to inappropriate site. So,
nano-based drug delivery mechanism leads to the significant approach in treatment of
cancer in recent times [18]
[19]
[20]
[21].
Fig. 1 Several parameters for the consideration for designing the
nanostructures.
Synthesis of nanomaterials
Synthesis of nanomaterials
Nanomaterial is synthesised mainly by two approaches classified as constructive and
destructive techniques. As seen in [Fig 2]
[22]
[23], Constructive technique is also known as the bottom-up approaches that
depicts the formation of nanomaterials from atom and crystals in sequential manner.
Several examples of bottom-up techniques for production of nanomaterials are
depolymerisation, chemical solution deposition, and biosynthesis [22]. Destructive technique is known as top-down
approaches, defines the decrease in particle size of a mass substance to nano-scale.
Examples include mechanical machining, electroplating, nanolithography, thermal
decomposition, along with physical vapour deposition are techniques involved in
synthesis of nanoparticles [23]
[24]
[25].
Fig. 2 Top-down and Bottom approach for the synthesis of the
nanomaterial.
Characteristics of nanoparticles
Characteristics of nanoparticles
The potential and applications of nanoparticles is greatly influenced by the
characteristics they possess. Nanoparticle characterization is determined by various
measurement techniques:
Particle size
The novel improvements in the formulation of existing drugs by pharmaceutical
companies are driven by an innovative approach of drug delivery to cure
diseases. These new formulations will be valuable to patients, and they will
also create an influential market force to drive the development of even more
upgraded delivery methods. The dimension and distribution of the nanoparticles
are mostly calculated with the help of electron microscopy [26]. The toxicity, distribution, and
targeting delivery are mostly dependent on particle size. The particle size is
inversely proportional to the ratio of surface area and volume of an entity. The
closeness of the drug to the surface of the nanoparticles will determine the
proximity of drug release to the target site [27]. The evaluation of particulates and units is done by examining
the pictures of scanning electron microscopy (SEM) and transmission electron
microscopy (TEM), although the bulk samples in fixed stages are estimated with
the support of laser diffraction methods. In the fluid phase, small pieces are
assessed using photon spectroscopy and centrifugation. In the same manner, the
minute pieces in the gaseous phase are measured by scanning mobility particle
size (SMPS), which provides exact through rapid value compared to other
methods.
External charge of nanoparticles
The surface charge on the nanocarrier determines its ability to interact to the
drug of interest. The surface charge along with the distribution stability in
mixture were measured a zeta potentiometer, whereas differential mobility
analyser (DMA), were utilized to determine the surface charge of nanocarrier in
gaseous [28].
Surface area
The surface area of the nanoparticles is an important factor as it directly
determines the performance of the carrier. It has different shapes like
sphere-shaped, plane, cylindrical, narrowed, and irregular forms with
crystalline or amorphous surfaces that helps importantly in determining the
properties of nanoparticles [29]. Brunauer
Emmett–Teller (BET) analysis determines the measurement of solid
surface area whereas, nuclear magnetic resonance (NMR) spectroscopy and
differential mobility analyzer (DMA) are utilized to measure the exterior area
of nanocarrier in liquid and the gaseous phase respectively [30].
Constitution
Normally synthetic mixture in the nanoparticles regulates its purity and proper
functioning. The presence of undesired elements in nanoparticles may lead to the
secondary reactions, reducing their efficiency. The measurement of the
composition is usually carried out with the help of electron spectroscopy for
chemical analysis (ESCA). There are several techniques that involve atomic
emission spectroscopy, ion chromatography and mass spectrometry, are involved in
chemical metabolism of the carriers along with wet chemical analysis [31].
Drug Liberation
The drug is liberated from the nanoparticles by depending on various components
such as temperature, drug desorption, drug distribution, pH, nanoparticles
matrix swelling and erosion [32]. Variety
of nanoparticles determines the drug liberation process. There are two types of
polymeric nanomaterials: nanocapsules and nanospheres. The chemical compound is
physically dispersed and released from the nanoparticles by eroding of the
template in nanospheres. Nanospheres are a uniform system in which the polymer
chains are arranged in uniformity to surfactants in micelle formation [33]. There is a rapid burst of drug release
due to the weak interaction to the large surface area of the nanoparticles
followed by a sustained release. On the other hand, nanocapsules are a
heterogeneous system in which the drug is located inside a reservoir composed of
the polymer. In nanocapsules, the diffusion of drug through the polymer is the
determining factor of drug delivery due to the release controlled by drug
diffusion through the polymeric layer [34]. The ionic interaction between the drug and polymer complexes which
inhibit the release of drug from the capsules is avoided by simply adding other
auxiliary agents such as polyethylene oxide-propylene oxide. This lowers the
interaction resulting into the greater efficiency of the drug- release to target
tissues [12]
[35].
Targeted drug delivery
The purpose of nanoparticles medicament administration is to bind and administer
its constituents to group of cells and reduce drug triggered poisonous effect to
healthy tissues. Therefore, to coat specific ligands such as antibodies,
peptides, designed proteins or nucleic acid on the surface of the nanoparticles
for its delivery to the targeted sites is significant [36]. The small molecules are the most
prominent targeting agents due to their advantages such as ease of preparation,
solidity, and chemical phenomenon [37].
However, nano-particulates can enter the human body via nebulizing, parental and
direct administered intake. Furthermore, lymphatic system distributes and
eliminates the particles due to the uptake from the blood stream vein [38]. As fluid regains, many foreign
materials and chemicals from the tissues are also picked up and as the fluid is
filtered back into the blood, the lymph nodes detect foreign matter passing
through and macrophages engulf and clear it from the body [39]
[40].
Types of nanostructures used for drug delivery
Types of nanostructures used for drug delivery
Organic Nanoparticles
Information of several natural compounds face concerns associated with the
clinical trial phases as the use of large-sized materials in drug delivery
possesses key challenges of in-vivo instability, poor absorption, solubility,
bioavailability, toxic effect of drug and lack of target-specific delivery.
Therefore, using a new method of drug delivery with target specificity is an
important approach for solving the critical problems faced by natural compounds.
The nanoparticles like dendrimers, micelles, liposomes, and ferritin are
polymers used in drug delivery system. These types of nanoparticles are
biodegradable and non-toxic which makes them suitable for drug delivery without
side effects [21]
[41]. Some of the organic nanoparticles
possess void core known to be as nanocapsules as represented in [Fig. 3]
[42]. The nanoparticles such as micelles
and liposomes are sensitive towards electromagnetic emission. Their applications
and competency are determined through their carrying capacity, stability and
drug delivery system [43]. The organic
nanoparticles are broadly used for drug deliverance because of their high
efficiency [44].
Fig. 3 Organic nanoparticles prominently used for drug
delivery.
Carbon based Nanoparticles
In 1991, Carbon based nanoparticles structures were discovered mainly constituted
of carbon nanotubes and fullerenes [45]. A
carbon nanotube comes with cylindrical framework and is distributed as single
walled carbon nanotube (SWCNT) and multi walled carbon nanotube (MWCNT) [46]. A carbon nanotube has distinctive
properties like thermal conductivity lengthwise and non-conductivity diagonally
of the tube along with mechanical strength, optical properties and electrical
conductivity which have biomedical application. Moreover, Carbon nanotubes could
be customized chemically into specific groups, molecules, or polymers to justify
the properties suited for biological application. For instance, carbon nanotubes
are developed for drug application. However, cytotoxicity is an area which has
showcased the interest of research because of its inadequacy [47]
[48].
Fullerenes
Fullerenes are the carbon allotropes having a dimension of approximately
7 m in diameter with sixty carbon atoms structures of hollow cage called
as shortened icosahedrons as shown in [Fig.
4]. Due to the various properties like high strength, heat resistance,
electrical conductivity, structure, and electron affinity it has wide commercial
applications [49].
Fig. 4 Structural representation of Fullerene – an
allotrope of carbon.
Fullerenes are extensively studied nanoparticles because of its uses in medicinal
field such as in binding particular antibodies to the system to point resistant
bacteria. Few researchers have carried ample amount of study on fullerene
toxicity that indicated carbon nanoparticles were most efficient to use for drug
administration. Moreover, other carbon-based nanoparticles such as graphene,
carbon nanofiber, carbon black, etc have unique properties like large breaking
strength, soft, springy, temperature and power conductivity, resistance to UV
degradation and due to the mechanical properties, they can be modified to use in
delivery system [50].
Inorganic Nanoparticles
An inorganic nanoparticle includes metal and metal oxide-based nanoparticles.
Metal-based nanoparticles consist of several metals like aluminium, cadmium,
copper, gold, iron, lead, silver, zinc, etc. which are mostly employed for
production of nanoparticles shown in [Fig
5]
[51]. These are synthesized into nano-size
particles with the help of either constructive or destructive methods. Moreover,
all metals can be synthesized into nanoparticles [52]. They have unique properties like sizes
as low as 10 – 100 nm, shapes like spherical and cylindrical,
surface properties like surface charge, crystalline and amorphous structure,
cross reactivity, and delicacy to environmental factors such as air, moisture,
heat and sunlight etc [53]. Similarly,
Metal oxides-based nanoparticles are type of nanoparticles which are produced to
modify the properties such as increased reactivity and efficiency as compared to
metal-based nanoparticles [54 ]
[Fig. 6].
Fig. 5 Examples of Inorganic Nanoparticles.
Fig. 6 Lipid Nano-particle is used as drug delivery vehicles.
Lipid based Nanoparticles
Lipid based nanoparticles consist of lipid and an array containing rigid
fat-soluble molecules and similarly their outside core is stabilized by
surfactants and emulsifier [55]. Fat
containing molecule is normally spherical in shape with a diameter ranging from
10 – 100 nm. These nanoparticles have a wide range of
applications especially in the biopharmaceutical field as drug carriers,
delivery, and RNA release in tumour therapy. Hence, the field of nanotechnology
is on verge of exponential growth [56].
Polymeric based Drug Delivery system
Polymeric materials have already revolutionized the world of biomaterials. An
efficient amount of work has already been done to integrate polymeric
nanomaterial with drug delivery systems due to the promising advantages.
Polymeric materials are associated with several characteristics which make
polymeric material ideal for biological purposes particularly in medicament
administration. Some of the favourable properties of these materials include
excellent biocompatibility and biometric behaviour, in addition to being
relatively easy to design and prepare. When incorporated into drug delivery
systems, polymers have demonstrated their unique capacity to release therapeutic
agents to specified target bunch of cells effectively [57].
Quantum Dots
Semiconductors are promising nano-sized crystal with dimension of around
2–10 nm and are used as fluorescent labels [58]. It consists of inorganic core which
indicates about the colour emitted and an aqueous organic coated covering to
improve optical properties. The biomolecular junction of the quantum dots can be
modified according to the targeted biomarkers [59]. Quantum dots centres are produced by cadmium selenide, or
cadmium sulphide. Similarly, the outer core is produced on the middle with the
highest bandwidth to impart power insulant protection of the florescence
characteristics. Their physical size shows great deal of importance and owning
to the narrow size, high photo-stability, broad UV excitation and high
fluorescence, quantum dots are used for tracking intracellular process for
longer duration, to invite bio-imaging and real time monitoring [60]. The applications of quantum dots are
in wide areas such as immunoassay, diagnostic tools, DNA hybridisation,
fluorescence imaging of tissue, Genetic therapy, marking of cells, remedial
tools and as a carrier of agents [61].
Below [Table 2] represents different kind
of nano carrier functional along with its characteristics, advantages, and
applications in drug delivery system [62].
Table 2 Different kind of nano-carrier functional in drug
delivery system [63].
|
Name of Nanoparticle
|
Characteristics
|
Advantages
|
Application
|
Reference
|
|
Liposomes
|
Biocompatible, offer easy entrapment, phospholipid
vesicles
|
Offer active and passive delivery of various agents such as
gene, protein, peptides etc.
|
Enhanced solubility, Controlled targeted drug delivery
|
[63]
|
|
Carbon nanotubes
|
Unique strength, electrical properties such as semiconducting
conducting, insulating,
|
Cell specificity, reduced toxicity and increases drug
efficacy.
|
Gene and DNA delivery.
|
[63]
|
|
Fullerenes
|
Composed of 60 Carbon atoms with dimension around 7 Å
in diameter.
|
Free radical scavenger and stimulate host immune response and
production of antibodies.
|
Diagnostic, Drug transport, Photosensitizer etc.
|
[63]
|
|
Dendrimers
|
Complex Branching
|
It has a size of >10 nm therefore can easily
penetrate through cells carrying drugs.
|
Uniform size distribution and controlled drug delivery to the
targeted tissues.
|
[63]
|
|
Polymeric nanoparticles
|
Biocompatible with drug protection and biodegradable.
|
Effortless design and different structures
|
Efficient carrier for controlled drug delivery.
|
[63]
|
Drug Targeting Approaches
Drug Targeting Approaches
Drug targeting strategies are categorised into two approaches namely passive and
active targeting as shown in the below [Fig
7]
[63].
Fig. 7 Active and Passive approach of drug delivery by nanoparticles
to the targeted tumour cells.
Passive Targeting
In passive targeting, the nanocarrier carrying the drug compound doesn’t
release through body mechanisms such as excretion, phagocytosis, or
opsonisation. One such highly used approach of nano-level techniques is
nanomedicines which helps in diagnosing, treating, and preventing from further
complications by increasing the localisation of drugs to target infected tissues
by passive targeting mechanism called as Enhance Permeability and Retention
(EPR) effect. The flow of the carrier remains continuous in the blood stream
until it binds to the target receptor by properties like size, temperature, pH,
or shape. Sudden gathering of the drug at specific areas with leaky vasculature
commonly known as Enhanced Permeation and Retention (EPR) effect is based on
passive targeting [64]. Nanomedicines
should be large enough to resist the speedy blood flow but also small enough to
get around easily from the capture by macrophages fixed in the
reticule-endothelial system like liver and spleen. Moreover, the hydrophilic
surface attained by coating the surface of nanoparticles with polyethylene
glycol (PEG) also helps from capture by macrophages. Direct drug injection,
catheterization and gathering of chemotherapeutic agents in solid tumor are few
common examples of passive targeting [65].
Ligand receptor complex can be greatly selective in this type of targeting by
giving the accurate way to targeted site delivery. Moreover, nanoparticles face
numerous resistances such as mucosal barriers, non-specific drug accumulation
and delivery due to uncontrolled drug release [66].
Active Targeting
In active targeting, ligands like small molecules, antibodies, aptamers and [67] interact with the drugs and delivery
system to facilitate the targeting on the surface of the specific cell. Drug
targeting via magnetic field and ultrasonic energy are also considered as active
targeting. This approach has significant and wider opportunities and
alternatives for drug delivery [68]. The
two general important attributes of nano-based drug delivery system are:
Target specificity by nanocarrier
Proper dimension and interaction of ligands provide efficient means of drug
delivery along with concentrated non-specific toxicity [69]. The biological ligand present on
the surface of nanoparticles interacts with receptors located on the
diseased tissue. Association with antibodies will give suitable binding to
the target sites and the endocytosis will be improved with properly adjusted
binding affinities [70].
Drug released time
To avoid non-specific toxicity, the nanocarrier moving in the blood stream
should not remove the drug encapsulated in it and remain attached until it
reaches the target site for release. To overcome it, engineered nanocarrier
with several layers is synthesized where every layer will have one drug and
their release will be determined in conformity of suitable timing in
sequential order for combination therapy [71].
Drug Targets in the Body
A target in the living organism to which the entity like ligand or a drug bind
resulting into the change in function of body is an important aspect in drug
delivery. The main targets in the living system are discussed as below:
Receptor
Receptors are generally located on cell membrane which allows specific drug
carrier interaction with cells ingested by means of receptor mediated
endocytosis (RME) [72]. The folate
receptors in the cancer cells which are overly expressed are useful for drug
delivery in cancer including malignancies in lung, brain, ovary, and breast
[73]. Moreover, peptide receptor is
expressed in high amount in some tumor cells which results into the conjugation
of a peptide to drug carriers, thus allowing precise targeting of cytotoxic
substance with decent interaction with the receptors [74].
Lipids
Lipids located on the cell membrane are emerging as novel approach as drug
targets. Signal transduction mechanisms are affected inducing apoptosis due to
the interaction of phospholipids with cell membrane results into altering the
composition, membrane permeability and flexibility of the lipid components [75]
Proteins/Antigens
The proteins/antigens are located on cell surface and expression of
various proteins/antigens on cell surface shows significance in
biochemical activity of cells which can be interpreted by using monoclonal
antibodies against these proteins/antigens [76]. In drug targeting, tumor specific
antigen can be used on all cells located in the tumor and similarly on tumor
cells itself [77]. The growth factor known
as erythroblastic oncogene B (erbB2) is over expressed on tumor cell surface in
20–30% human breast adenocarcinomas [78]. It is used for immunotherapy with
liposomal doxorubicin formulation attached to anti-growth factor antibody.
Moreover, the growth factor shows efficient accessibility, consistent
distribution on the infected cell with low expression on healthy cells [79].
Applications
Cancer treatment
The most widely recommended therapies offered to cancer patients typically
involve chemotherapy, radiation and/or surgery [80]. However, these options are associated
with several limitations for example chemotherapeutic agents, while highly
effective in their ability to kill rapidly dividing cancer cells, are associated
with severe cytotoxic effects to normal cells. Due to these challenges,
nanotechnology-based targeted drug delivery systems have been widely
investigated for their potential to not only reduce the adverse effects
associated with traditional antineoplastic drugs, but also provide enhanced
therapeutic efficacy. The [Fig. 8]
depicts the active targeted drug delivering by the nanoparticles to inhibit the
effect of active tumor [81]
[82]
[83].
Fig. 8 Active tumor targeting by Nanoparticle drug delivery.
Among the various nanotechnology-based systems that have been investigated;
polymeric nanocarrier have attracted a considerable amount of attention.
Scientists have successfully manipulated the core-shell structure of polymeric
nanocarrier to both encapsulate and conjugate drugs to this core [84]. As well as providing a protective
barrier between healthy tissues and the encapsulated drug, polymeric nanocarrier
have improved drug pharmacokinetics and enhanced the accumulation of
encapsulated drugs directly into tumours [85].
CNS Disorders
The blood brain barrier (BBB) acts as a resistant which restrains and limits the
passage of substances into the brain. While BBB serves to protect the brain
against invading pathogens and potential neurotoxins, it also significantly
limits the passage of therapeutic agents into the brain to treat Central Nervous
System (CNS) conditions. Several kinds of nanoparticle carriers are investigated
to conquer these challenges, some of which include metallic, polymeric, lipid
and targeted nanoparticles carriers [86].
In comparison to metallic nanoparticles, polymeric nanoparticles are soft, more
flexible, and less dense, allowing for these particles to be more malleable for
therapeutic drug encapsulation [87].
Various properties of polymeric nanoparticles, such as their dimension, external
charge with aspect ratio could be altered to meet the demand of broad spectrum
of drugs [88]. Polymeric nanoparticles
undergo a process called endocytosis, which involves the engulfment of the
nanoparticles by the accepting cell’s membrane to cross the blood brain
barrier (BBB) [89]. Several studies have
also investigated different methods, such as the addition of endogenous
substances to functionalize the polymeric nanocarrier surface to further enhance
the site-specific delivery of encapsulated drugs into the brain [90].
HIV and AIDs treatment
Nanoparticles which transport antiretroviral drugs to the targeted sites are
emerging as promising tools in treatment [91]. Nanoparticulate could be augmented with vaccines to thwart HIV
infections more effectively. To achieve it, a mixture of various drugs which is
commonly called as Highly Active Antiretroviral Therapy (HAART) can be utilized
[92]. Nano-biotechnology plays
significant role in drug delivery to the targeted sites in the body and improves
flexibility. Antiretroviral drugs, when taken orally, should traverse the
epithelial resistance. Nanoparticles via endocytosis/phagocytosis
efficiently traverse Blood Brain Barrier (BBB) and many studies have been
reported depicting efficient release of anti HIV medication [93].
Future Prospects
Nanomedicines are a current fascinating field of exploration to detect harmful
diseases along with providing the cure to it by following proper parameters. The
design of Nano-based drug delivery system requires assistance from various fields of
people like mathematicians, biologist, chemists, and medical scientists. In near
future, detailed tracing and analysis is required in integrity, surface
characteristics, bio-distribution, pharmacokinetics, and immunological effects.
Advanced technologies are essential to explore the challenges more efficiently.
Also, there should be evaluation framework to analysis the nano-based drug delivery
system and animal-based representation should be recognized. The proper targeting,
target examination, protection of patient and commercial role of nano-based drug
delivery systems should be of beneficial guidance. Moreover, understanding the
biological nature and heterogeneity of the target will provide efficient help for
synthesis of nanoparticles for the treatment. Finally, more attention should be on
the synthesis of a structurally simple and reproducible drug delivery mechanism as
it possesses high potential to read the patients. However, regulatory mechanism and
safety evaluation of nano-based medicines will be valuable study for the further
improvement in the future. The nanomedicines research has now revolutionized the
drug delivery approach in human body.
Conclusion
Nanotechnology is a fast-growing interdisciplinary field that has important
application in health-based industry. Nano-based drug has prominent application in
drug delivery and development of techniques which have formed novel approach and
provided opportunities to customized and safe treatment options. Nanotechnology is
utilized for drug delivery with the help of nano-carrier for therapy and handling of
chronic disease such as cancer, hypertension, HIV, and diabetes. Drug loaded
nanomaterials have become one of the most important aspects in medicine due to
various advantages of nanoparticles in drug administration such as drug targeting,
controlled drug release, protection of therapeutic payload and improved
bioavailability. Development of new drug delivery systems is providing advantage for
pharmaceutical sectors as well.
Credit authorship contribution statement
Credit authorship contribution statement
Aditya Kate: Conceptualization, Investigation, Review of literature, Editing,
Correction and Writing – Original draft. Mohit Mishra: Review, Formal
analysis, Proof reading, Editing and Supervision. Bhairav Prasad: Proof Reading.
Jaya Pandey: Final Correction, Critical Revision and Editing. Ragini Dubey:
Finishing and Editing Arzoo Sinha: Preparation of figures.
All authors approved the manuscript.
Declaration of competing interest
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal
relationships that could have appeared to influence the work reported in this
paper.
