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.