Aveneu Park, Starling, Australia

NANOTECHNOLOGY . . . . . .

 

NANOTECHNOLOGY AS A DRUG DELIVERY
SYSTEM

 

 

 

 

 

 

 

                 

                           source: Scientific
India

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

 

 

 

 

 

 

 

 

 

 

Prepared for

Katharine Ferguson, Seneca College

 

Prepared By

David Kazek

 

 

 

 

 

 

 

 

 

                                                                                                 

 

 

TABLE OF CONTENTS
1.0        INTRODUCTION.. 3
2.0        NANOTECHNOLOGY FOR DRUG DELIVERY.. 4
2.1 Controlled Delivery. 4
2.2 Polymer-drug conjugates. 5
3.0        NANOPARTICLES-BASED
DRUG DELIVERY SYSTEM… 6
3.1 Types of Nanoparticles. 7
3.2 Liposomes. 7
3.3 Nanotubes. 7
3.4 Inorganic Nanoparticles. 8
4.0        USAGE FOR TREATMENTS OF AILMENTS. 8
4.1 Cancer Treatment. 9
4.2 Treatment of Neurological Disorders. 10
5.0        SAFETY AND ENVIRONMENTAL ISSUES. 11
 

 

 

 

 

 

 

 

LIST OF TABLES AND FIGURES

 

TABLES

Table 1: Comparison of
Nanoparticle Drug Delivery Systems . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . .  6

FIGURES

Figure 1: Artist image of
a liposome used as a drug delivery system . . . . . . . . . . . . . . . . . . .
. . . . . . . 7

Figure 2: Cells with carbon
nanotubes coated in protein . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . 8

Figure 3: Nanoparticle
used for cancer treatment . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . 9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.0             
INTRODUCTION

 

Nanotechnology
is the study and application of microscopic machines on the molecular scale. These
kinds of machines are smaller than 100 nanometers, or one billionth of a meter.
At this small size, the properties of materials and objects physically react
differently to their environment than their larger counterparts. Nanotechnology
is a relatively new kind of technology, dating back the to 1980’s with one of
it’s first applications being the invention of the scanning tunneling microscope
in 1981 (Bai). There are many applications for nanotechnology, including but
not limited to: medicine, information technology, robotics, military equipment
and so on. One specific branch of the use of nanotechnology in the medicine
field is the use of it to deliver drugs to the human body.

The
current methods of drug delivery to the human body come with many challenges,
the main factor being the large size of materials used. The result of this can
leads to poor bioavailability, as well as absorption through the intestines.
Another problem is that sometimes the drugs do not reach their intended target,
and fail in providing the support to the afflicted area as needed. New
advancements in this field of technology allow the drugs to have a protective
coating, which is called a nanostructure. This structure protects the drugs
from degradation in the body as the drugs make their way to the intended
target. This development allows delivery of drugs with poor water solubility
the means to bypass the liver, which prevents the drugs from being metabolized
by the body. Almost 50% of drugs are delivered to the human body via the mouth,
and “these methods provide more advantages due to patient acceptance and ease
of administering the necessary drugs” (Haghi, 1). The microscopic size of these
machines allows them to pass through tissues, giving easier and more efficient
access of the drugs to cells. The use of nanotechnology can help improve the
bodies acceptance of drugs intended to help it, as well as this type of system
being more effective and safe. These types of applications can serve as the
carrier for drugs that are used in the treatment of chronic diseases, such as
cancer, HIV, diabetes, and asthma.

 

 

The
contents of the report will be the science behind this kind of technology,
followed by the specific ways that nanotechnology can be used as an effective
drug delivery system, and why is should be further researched. At the end of
the report there will be a conclusion of the main points of the report, as well
as a recommendation of if this type of technology should be further researched.

 

2.0             
NANOTECHNOLOGY FOR DRUG DELIVERY

2.1 Controlled Delivery

 

As
medicine advances, increasingly more drugs are being created to treat specific
diseases and ailments. Treatment of these diseases and ailments depends on the
type that is being treated, and the severity of the ailment. For most ailments,
treatments are available in the form of pills or capsules; almost 50% of the
drugs people take are orally. The method that is used to deliver the drug to
the body can significantly affect its potency and efficiency. This method of
introducing drugs to the body can have both positive and negative side effects,
as some drugs have concentration ranges. These ranges vary from drug to drug,
however if the concentration of drugs is too strong, it can have negative side
effects, such as increased toxicity or no benefit whatsoever. Taking drugs
orally is a slower way of introducing drugs to the body, and as such scientists
are looking for new ways to improve the delivery of drugs to the human body.
The most conventional was to deliver drugs are orally, transdermal (through the
skin), injection and implants. These methods, however, are not the most
efficient are delivering their drugs to their intended target. A new type of
drug delivery system is the use of nanotechnology, which would provide a more
efficient and beneficial deliverance of drugs to the human body. This new kind
of technology focuses on the minimalization of harmful size effects to the
body, as well as minimizing degradation of the drug as it travels through the
body. There are new strategies that are being developed that will aid in
“controlling the pharmacokinetics, pharmacodynamics, nonspecific toxicity,
immunogenicity, bio-recognition, and efficacy of drugs” (Kumar, 2.1). The
strategies that are being developed are known as drug delivery systems (DDS),
and the base of them is on “interdisciplinary
approaches that combine polymer science, pharmaceutics, bioconjugated
chemistry, and molecular biology” (Kumar, 2.1). There are many drug carriers
being developed, and each has a different purpose. They include soluble
polymers, microcapsules, cells, liposomes, and lipoproteins. Each different
carrier can be altered to respond to its environment differently, such as
changes in temperature or acidity levels, and they can be targeted at specific
parts of the body to deliver the proper dosages of the drug. There are two main
ways for distribution of the drug to be controlled, which are: passive
targeting and active targeting.

These types of targeting are designed to avoid
the release of the drugs to areas of the body where it is not needed. The
benefit of controlling the distribution of the drug minimizes potential side
effects, and to improve the efficacy of the drug, when compared to the standard
way of distribution. The release of the drugs before they reach their intended
target can cause unwanted side effects, and a slow release can cause resistance
of the drug in the cells. Control over the delivery of the drugs is also
desirable in certain cases, such as in pain medication, where drugs would be
administered automatically on a set time.

2.2 Polymer-drug conjugates

 

Water-soluble
polymers are another option for drug delivery systems that are polymers
chemically combined with a drug. Drugs with small molecules have a low water
solubility, and they spread out in tissues well. However, due to their ability
to spread out over large amount of tissue this can lead to increased toxicity
in the body around the target area. These systems must be made to be
biocompatible and hydrophilic to increase their solubility and allow the drugs
to be spread out in a more controlled manner around the target area, decreasing
the risk of unwanted toxicity.

 

 

 

3.0             
NANOPARTICLES-BASED DRUG DELIVERY SYSTEM

As stated previously, there are many different types
of carriers that can be used for the delivery of drugs to the body. Below is a
comparison of some types of carriers (Table 3.1) which gives details on the
size, advantages, disadvantages as well as the drugs that they carry.

Table
3.1: Comparison of Nanoparticle Drug Delivery Systems (Yih, 2006)

 

 

3.1 Types of Nanoparticles

 

3.2 Liposomes

Liposomes
are a very versatile type of carrier that can be used for drug delivery. They
are usually round, and very small. They also have multiple aqueous parts that
are enclosed two types of molecules, giving it hydrophobic and hydrophilic
capabilities. Liposomes can be single or multilayered, and come in many
different sizes, depending on their payload. They are commonly used as carriers
for “various bioactive agents including drugs, vaccines, cosmetics and
nutaceuticals” (Emeje et al.). Liposomes are very effective at reducing the
excess toxicity of the drugs they are carrying, due to the ability to cover
them with polymers, such as polyethylene glycol (PEG). Liposomes, by design,
are made to attach to the membranes of cells to deliver the drugs, and can also
“transfer drugs following endocytosis” (Kumar, 2.2.1.4).

 

 

 

 

 

 

Figure 1: Artist rendition of a liposome used as a
carrier for drugs (Kosi Gramatikoff, 1999)

                                   

3.3 Nanotubes

 

This
type of carrier is made of carbon chains linked together, essentially forming a
tube, and as such they are strong and flexible. Two professors at Carnegie
University have researched a type of protein that would wrap itself around the
carbon nanotube and the drugs. The proteins are engineered to be easily
accessible by cells, and by wrapping the drugs in the protein the cells take in
the drugs much quicker. Since the nanotubes are made up of carbon, they are completely inert to the cell,
and as such they do not break down leading to a large amount of the drug being
administered before the cell start to be impacted (Durham).

 

 

 

 

 

 

 

 

 

Fig 2: Cells with nanotubes covered in proteins.
(Carnegie Mellon University Materials Science and Engineering)

 

3.4 Inorganic Nanoparticles

Inorganic
nanoparticles are usually made of materials such as alumina or silica. They can
also be made of metals, metal sulfides and metal oxides (Kumar, 2.2.1.1). These
nanoparticles vary in size, and they can be constructed to be porous, and can
provide shielding to protect its payload. These types of nanoparticles are
“relatively stable over broad ranges of temperature and pH” (Kumar, 2.2.1.1),
but they lack the ability to biodegrade and they dissolute slowly. The slow
degradation of the nanoparticles can lead to safety concerns of the long terms
effects that it may have on cells and the body.

 

4.0       USAGE
FOR TREATMENTS OF AILMENTS

The
main purpose for the development of this kind of technology is for the ability
to be able to treat diseases and ailments easier and quicker that what current
medicine can provide. Many diseases, such as cancer, HIV, Aids etc. are very
hard to treat, and require multiple treatments, as well as the high cost that
comes with the treatments. The use of nanoparticles to be programmed and
deliver the drugs right to the source would greatly increase the success rate
of treatment, and it would lower the overall costs of the treatment.

4.1 Cancer Treatment

There
are many different types of cancer, and each type needs to be treated
differently. Certain types of cancer, such as brain tumors, are hard to treat
as anticancer drugs need to be gain access to the tumor cells. Many tumors have
a poor blood vascular system with poor blood flow, and this can lead to the
blood-brain barrier blocking the drugs from reaching the tumors. Nanoparticles,
however, can breach this barrier by acting as carriers and delivering the drugs
to the tumor and help in treating it.

 Traditionally, nanoparticles are used to
reduce the amount of toxins used in chemotherapy through selective targeting of
tumor cells and delivery of the drugs to the tumor tissues. The most common
method of administering anticancer drugs are through injection of infusion.
This leads to a high peak in the “maximum tolerable concentration of the drug
in the plasma and then fast excretion from the circulation system” (Mei et al).   Another type of cancer treatment is
radiation therapy, which uses high-energy radiation to kill cancer cells. In
the process of killing cancer cells, healthy cells can also be killed or
damaged, and this can lead to damage of the cells’ DNA. Due to the dangerous
nature of this form of cancer treatment, radiation levels must be kept low
enough to not be too toxic to the surrounding cells (Treatment and Therapy).
The most effective way to deliver anticancer drugs to the body is orally, as it
both allows patients to take the treatments by themselves and it reduces the
medical costs of the patient. One way the nanoparticles can be used is to have
them equipped with electromagnetic radiation modules, and have the
nanoparticles target the tumor cells, leaving the healthy cells untouched by
radiation. Essentially, this increases the efficacy while giving out the same
amount of radiation and toxicity to the surround cells.

 

 

 

 

 

                                  

 

 

 

 

 

Fig 3: Artists rendition of a nanobot targeting a
cancer cell (Shutterstock)

 

4.2 Treatment of Neurological Disorders

The two components
of the nervous system, the central nervous system (CNS) and the peripheral
nervous system (PNS) are what give a person part of their senses. The parts of
the CNS include the brain, optic nerves, and the spinal cord, while the PNS
makes up the rest of the nerves in the body. These nerves allow a person to
sense things, such as touch, and movement. There are many disorders that can
affect the CNS, and some are more severe than others. Disorders such as
mirages, epilepsy, depression, and even neurodegenerative disease like
Alzheimer’s are due to a part of the CNS not functioning properly. The basic
application of nanotechnology for neurological disorders would be the
nanomaterials interactions with neurons at the molecular level, and they “can
be used to influence and respond to cellular events” (Kumar, 3.6.2.1). Most
neurodegenerative diseases are linked to the loss of spinal cord and brain
cells. A strategy for treatment of these diseases it to use nanoparticles to
support and promote growth of neuritis and axonal by “implanting
nanometer-scale scaffolds using tissue-engineering approaches.” (Kumar,
3.6.2.1)

The most promising
materials for this kind of application are nanotubes and nanofibers, as these
materials mimic tube like structures. New techniques have been found which can
make nanotubes out of various materials, such as: DNA, proteins, silicon,
polymers and even glasses. The result of these new materials being used leads
to less toxicity and an increase in the biocompatibility of the nanotubes.

 

5.0 
      SAFETY AND ENVIRONMENTAL ISSUES

 While there are many benefits that can come
from the use of nanoparticles as a drug delivery system, there are comes also
disadvantages and risks. One of the main risks is that the engineered particles
can “form large aggregates that can alter the bioavailability and this the
toxicity of a material” (Nanowerk). Naturally forming nanoparticles are
structured randomly, and they diffuse in a distributed manner throughout the
environment. Engineered particles, on the other hand contain only nanomaterials
that are uniform in shape, size and structure, giving them unique properties.
Nanomaterials can undergo many chemical processes in the environment, such as
changes in pH, presence of light and organic or inorganic materials. The
stability of the nanoparticle out in the environment is a decisive feature in
its potential toxicity. As there is very little data available, the full
effects of what could happen are unknown. Nanoparticles come in many different
shapes and sizes, so it is difficult to determine exactly what they could do
out in the environment.

In the air, the
nanoparticles move rapidly, and they “tend to aggregate into larger structures”
(Nanowerk). Detection of the particles in the air is difficult because
measurements of these specific particles are hard to distinguish from natural
ones. The distribution of nanoparticles through the air is the slowest way to
deposit the particles due to the small diameter of them. When nanoparticles
come into contact with water, they spread out and are evenly distributed. They
become unstable due to rapid adherence from electrostatic forces and then sink
due to gravity. Bodies of water contain dissolved materials, which includes
nanomaterials. The addition of engineered nanomaterials binds the natural and
engineered particles together. Just like in the air, the engineered particles
are affected by acidity levels, as well organic material.

There are many
potential environmental factors that can influence how the engineered particles
behave, such as dissolution, transformation, binding to other particles,
mineralization, diffusion, and resuspension. While nanoparticles are known to
be in the environment, there are “no ecotoxicological studies…that could
explain in detail the mechanisms of uptake, distribution, metabolization and
excretion of nanoparticles” (Handy, 320). There is “no quantitative data …
available for even a single nanomaterial” (Nanowerk). The assumption is that
these engineered nanoparticles that are tightly bound together post a very
small or no risk at all to the environment. Long term studies of the effects of
the engineered materials would need to be made, as currently there are no
concrete studies that prove how much damage the nanoparticles can do.

 

6.0       CONCLUSION

 

There
are many applications for the use of nanotechnology, and using it as an effective
drug delivery system would be beneficial to many people. There is still ongoing
research to find the best nanoparticle to use, as there are drawbacks and many factors
that would need to be researched to fully utilize the system properly. Having the
ability to deliver the drug to the target in a person’s body with incredible accuracy
and proper dosage can improve many people’s lives, as well as save people a lot
of money. There are still many tests that need to be done in this field before the
use of nanoparticles can be mainstream. The usage of nanoparticles also brings about
a risk, and unknown factors can cause the nanoparticles to be more harmful than
helpful. Using this kind of technology allows the deliverance of drug to areas where
conventional methods cannot reach, such as anticancer drugs to the brain in events
of a tumor, or using nanoparticles to repair parts of the nervous system to help
combat neurodegenerative diseases. All of this research is ongoing, and at it’s
current stage it is too expensive to produce these kinds of drugs and use them instead
of conventional methods of treatment. While the ability to have an all in one drug
would be amazing, the technology and research to fully utilize the nanoparticles
to their fullest extent and not have any factors of risk is still a long way off.

 

 

 

REFERENCES

Bai, Chunli. Scanning Tunneling Microscopy and Its
Application. 2nd ed., vol. 32, Springer, 2000.

Mei, Lin ; Zhang, Zhiping ; Zhao, Lingyun ; Huang, Laiqiang ;
Yang, Xiang-Liang ; Tang, Jintian ; Feng, Si-Shen. Advanced Drug Delivery
Reviews, 15 June 2013, Vol.65(6), pp.880-890Peer Reviewed Journal

 

Haghi, A. K., and E. A. Castro. Nanotechnology in Drug Delivery:
Strategies, Technologies and Applications. Nova Publishers, 2014.

 

Kumar, Narendra,
and Rajiv Kumar. Nanotechnology and Nanomaterials in the Treatment of
Life-threatening Diseases: Nanomedicine, Diagnostics and Drug Delivery. William
Andrew, © 2014. Books24x7. Web. Jan. 3, 2018. http://common.books24x7.com.libaccess.senecacollege.ca/toc.aspx?bookid=58847

Asmatulu,
Ramazan. Nanotechnology Safety. Elsevier Science and Technology Books, Inc., ©
2013. Books24x7. Web. Jan. 3, 2018. http://common.books24x7.com.libaccess.senecacollege.ca/toc.aspx?bookid=56560

 

TC Yih M
Al-Fandi Engineered nanoparticles as precise drug delivery systems J Cell
Biochem 15 2006 1184–1190

Torchilin, V.
(2006). Nanoparticulates as drug carriers. London: Imperial College Press.

Emeje , Martins
Ochubiojo, et al. “Nanotechnology in Drug Delivery.” Nanotechnology in Drug
Delivery, Recent Advances in Novel Drug Carrier Systems , InTech, 2012.

Durham, Emily.
“Using Carbon Nanotubes for Drug Delivery.” Phys.org – News and Articles on
Science and Technology, Phys.org, 17 May 2016,

“Treatment and
Therapy.” National Cancer Institute, www.cancer.gov/sites/ocnr/cancer-nanotechnology/treatment.

Mitra, A., Cholkar, K.,
& Mandal, A. (2017). Emerging nanotechnologies for diagnostics, drug
delivery and medical devices.

“Nanowerk.” Nanowerk
Nanotechnology Portal, www.nanowerk.com/spotlight/spotid=25937.php.

Handy, Richard D., et
al., 2008, The ecotoxicology of nanoparticles and nanomaterials: current
status, knowledge gaps, challenges, and future needs, Ecotoxicology 17,
315-325.

                                                                                                                                                             

x

Hi!
I'm Simon!

Would you like to get a custom essay? How about receiving a customized one?

Check it out