Targeted Magnetic Iron Oxide Nanoparticles for Tumor Imaging
Targeted drug delivery to tumor
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Transcript of Targeted drug delivery to tumor
Tasnim fariha noshin
Nazmul huda
Farzana naznin
Ariful islam
Noakhali Science & Technology
University, Pharmacy Dpt.
Tumors are a classic sign of inflammation. It
is a fluid-filled lesion that may or may not be
formed by an abnormal growth of neoplastic
cells that appears enlarged in size.
Tumor arises from-
Agents that damage genes: controlling cell
proliferation and that increase the tumor cell
migration.
Agents that do not damage genes: selectively
enhance the growth of tumor cell or their
precursors.
There are dozens of different types of tumors. They can be classified in two forms. These are-
Benign &
Malignant.
Benign: They are-
Slow growing
Capsulated
Non- invasive
Do not metastasize
Well differentiated
Suffix “oma”
Example : Fibroma, Adenoma, Emangioma, Ipoma, Eningioma
Malignant: They are-
Fast growing
Non-capsulated
Invasive & infiltrate
Metastasize
Poorly differtiated
Suffix “carcinoma” or “sarcoma”
The word cancer is derived from the Latin
word ‘for crab’ because cancers are often
very irregularly shaped, and because, like a
crab, they "grab on and don't let go." The
term cancer specifically refers to a new
growth which has the ability to invade
surrounding tissues, metastasize (spread to
other organs) and which may eventually lead
to the patient's death if untreated.
Cancer harms the body when damaged cells divide uncontrollably to form lumps or masses of tissue called tumors. Tumors can grow and interfere with the digestive, nervous, and circulatory systems, and they can release hormones that alter body function. Tumors that stay in one spot and demonstrate limited growth are generally considered to be benign.
More dangerous, or malignant, tumors form when two things occur:
a cancerous cell manages to move throughout the body using the blood or lymph systems, destroying healthy tissue in a process called invasion.
that cell manages to divide and grow, making new blood vessels to feed itself in a process called angiogenesis.
Cancers are caused by a series of mutations.
Each mutation alters the behavior of the cell
somewhat. Genes that regulate cell growth
and differentiation must be altered genetic
and epigenetic changes can occur at many
levels. These changes are shown below in a
simple mechanism:
Delivering a drug to a specific site in the
body where it has the greatest effect,
instead of allowing it to diffuse to various
sites, where it may cause damage or trigger
side effects.
Here specific interaction occurs between a
drug and its receptor at the molecular level.
Effective drug delivery system
Retain
Evade Target
Release
Drug targeting strategies have frequently been
divided into categories of “passive” and
“active”.
Passive targeting:
Passive targeting can differentiate
between normal and tumor tissues and has
the advantage of direct permeation to tumor
tissue. Drug administered passively in the
form of prodrug or inactive form, when
exposed to tumor tissue, becomes highly
active.
Nanoparticles follow the biological
mechanisms such as ERS (Enhanced Retention
System).
Size should be below 100 nanometers in
diameter and drug accumulates around the
tumors with leaky vasculature.
Active targeting:
By conjugating the nanoparticles with a drug
to desired target site, an active targeting
may be achieved.
Active targeting allows the increased
accumulation of the drug in cancer tissue.
Many different targeted therapies have been
approved for use in cancer treatment.These
are:
Hormone therapies,
Signal transduction inhibitors,
Gene expression modulator,
Apoptosis inducer,
Angiogenesis inhibitor,
Immunotherapies, and
Toxin delivery molecules.
It is a type of personalized medical therapy
designed to treat cancer by interrupting
unique molecular abnormalities that drive
cancer growth.
Targeted therapies are drugs that are
designed to interfere with a specific
biochemical pathway that is central to the
development, growth and spread of that
particular cancer.
Immunotherapy is designed to repair, stimulate, or enhance the immune system's responses using patients’ own immune systems to fight cancer.
It uses the body's own immune system to:
> Target specific cancer cells, thereby potentially avoiding damage to normal cells.
>Make cancer cells easier for the immune system to recognize and destroy.
>Prevent or slow tumor growth and spread of cancer cells.
Example: vaccine therapy.
Cancer is caused by changes in our genes.
Gene therapy is designed to modify cancer
cells at the molecular level and replace a
missing or bad gene with a healthy one. The
new gene is delivered to the target cell via a
‘vector,’ which is usually an inactive virus or
liposome, a tiny fat bubble.
1.Cancer cells can become resistant to them.
Resistance can occur in two ways—
the target itself changes through mutation so
that the targeted therapy no longer interacts
well with it.
the tumor finds a new pathway to achieve
tumor growth that does not depend on the
target.
2.Drugs for some identified targets are difficult
to develop because of the target’s structure
and/or the way its function is regulated in
the cell
The most common side effects seen with targeted therapies are diarrhea and liver problems, such as hepatitis and elevated liver enzymes.
Other side effects seen with targeted therapies include:
Skin problems (acneiform rash, dry skin, nail changes, hair depigmentation)
Problems with blood clotting and wound healing
High blood pressure.
Gastrointestinal perforation.
For cancer therapies, the ideal targeted drug
delivery system is the one that delivers the
drug only to the target tumor.
As tumors may not be eradicated by just
aiming at one target, it may also be
necessary to simultaneously aim at multiple
targets. Thus, it may be worthwhile to
develop “magic shotgun” strategies that
deliver multiple drugs, and/or deliver the
drug to multiple targets.