This document discusses tumor targeting drug delivery. It describes passive targeting, where nanoparticles accumulate in tumors through leaky vasculature, and active targeting, where nanoparticles are conjugated to a drug to target a specific tumor site. The document also outlines several targeted cancer therapies, including hormone therapy, signal transduction inhibitors, gene expression modulators, angiogenesis inhibitors, immunotherapies, and toxin delivery molecules. It discusses limitations such as drug resistance and side effects like diarrhea, liver problems, and skin issues. Finally, it proposes future targeted delivery systems could aim at multiple targets simultaneously.
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Tumor Targeting Drug Delivery Methods
1. tumor targeting drug delivery
By Tushar Chavan
M Pharmacy 2018-2019
K.Y.D.S.C.T.College of Pharmacy, Sakegaon
NMU, Jalgaon
Updated April 30, 2019
Email: tusharchavantsc@gmail.com
01. Tumor
īˇ It is an abnormal mass of tissue which is a
classic sign of inflammation.
īˇ 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.
īˇ The term cancer 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.
02. Drug targeting to tumor
Drug targeting to tumor have been divided into
categories of âpassiveâ and âactiveâ.
PASSIVE TARGETING:
īˇ Passive targeting can differentiate between
2. normal and tumor tissues and has the
advantage of direct permeation to tumor tissue.
īˇ Drug administered passively in the form of
prodrug or inactive form, when exposed to tumor
tissue, becomes highly active.
īˇ Nanoparticles follow the biological mechanisms
such as ERS (Enhanced Retention System).
īˇ Size should be below 100 nanometers in
diameter and drug accumulates around the
tumors with leaky vasculature. 5
Active targeting:
īˇ By conjugating the nano particles with a drug to
desired target site, an active targeting may be
achieved.
īˇ Active targeting allows the increased
accumulation of the drug in cancer tissue.
03. Targeted Therapies available in tumor
treatment
īˇ Many different targeted therapies have been
approved for use in cancer treatment. These are:
īˇ Hormone therapies,
3. īˇ Signal transduction inhibitors,
īˇ Gene expression modulator,
īˇ Apoptosis inducer,
īˇ Angiogenesis inhibitor,
īˇ Immunotherapies, and
īˇ Toxin delivery molecules
04. Treatment with targeted molecular
therapy
īˇ It is a type of personalized medical therapy
designed to treat cancer by interrupting unique
molecular abnormalities that drive cancer
growth.
īˇ 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.
05. Treatment with immunotherapy
īˇ Immunotherapy is designed to repair, stimulate,
or enhance the immune system's responses
using patientsâ own immune systems to fight
4. cancer. It uses the body's own immune system
to:
īˇ Target specific cancer cells, thereby potentially
avoiding damage to normal cells.
īˇ Make cancer cells easier for the immune system
to recognize and destroy.
īˇ Prevent or slow tumor growth and spread of
cancer cells. Example: vaccine therapy.
06. Treatment with Gene therapy
īˇ Cancer is caused by changes in our genes.
īˇ Gene therapy is designed to modify cancer cells
at the molecular level and replace a missing or
bad gene with a healthy one.
īˇ The new gene is delivered to the target cell via
a âvector,â which is usually an inactive virus or
liposome, a tiny fat bubble.
07. Antibody directed enzyme prodrug therapy
Stimuli Responsive drug release
īˇ The tumor microenvironment differs from the
normal cells microenvironment
īˇ Advantage of the difference in pH, temperature
5. and presence of enzymes is used to release the
drug in tumor microenvironment.
īˇ The rapid release of drug from its carrier is key
to the therapeutic efficacy of dosage form.
08. Limitations of tumor targeting Cancer
cells can become resistant to them.
*Resistance can occur in two ways
īˇ The target itself changes through mutation so
that the targeted therapy no longer interacts
well with it.
īˇ The tumor finds a new pathway to achieve
tumor growth that does not depend on the
target.
09. SIDE EFFECTS
The most common side effects seen with
targeted therapies are :
īˇ Diarrhea and liver problems, such as
hepatitis and elevated liver enzymes.
īˇ Skin problems (rash, dry skin, nail
changes, hair depigmentation)
6. īˇ Problems with blood clotting and wound
healing
īˇ High blood pressure.
10. Future perspectives
īˇ For cancer therapies, the ideal targeted drug
delivery system is the one that delivers the drug
only to the target tumor.
īˇ 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 âmagic shotgunâ
strategies that deliver multiple drugs, and/or
deliver the drug to multiple targets.