EPPTB: Difference between revisions

Latest revision as of 03:33, 13 February 2025

Enhanced Permeability and Retention Effect[edit]

Diagram illustrating the Enhanced Permeability and Retention Effect

The Enhanced Permeability and Retention (EPR) Effect is a phenomenon observed in tumor biology, where macromolecular drugs and nanoparticles preferentially accumulate in tumor tissue. This effect is primarily due to the unique characteristics of tumor vasculature and the impaired lymphatic drainage in tumors.

Mechanism[edit]

The EPR effect is driven by two main factors:

Enhanced Permeability: Tumor blood vessels are often irregular, disorganized, and have wide fenestrations. This allows macromolecules and nanoparticles to pass through the vessel walls more easily than in normal tissues.

Retention: Tumors typically have poor lymphatic drainage, which means that once macromolecules and nanoparticles enter the tumor tissue, they are retained for longer periods.

These factors together enable the selective accumulation of therapeutic agents in tumor tissues, which can enhance the efficacy of cancer treatments while minimizing systemic side effects.

Applications[edit]

The EPR effect is exploited in the design of nanomedicines and drug delivery systems. By engineering drugs to be of a certain size and composition, researchers can increase the likelihood that these drugs will accumulate in tumor tissues via the EPR effect. This has led to the development of various nanoparticle-based therapies and liposome-encapsulated drugs.

Challenges[edit]

Despite its potential, the EPR effect is not uniformly effective across all tumor types or patients. Factors such as tumor type, size, location, and the presence of hypoxia can influence the extent of the EPR effect. Additionally, the heterogeneity of tumor vasculature can lead to variable drug delivery and efficacy.

Future Directions[edit]

Research is ongoing to better understand the EPR effect and to develop strategies to enhance its effectiveness. Approaches include the use of vascular normalization agents, hyperthermia, and ultrasound to improve drug delivery to tumors.

Related pages[edit]

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-'''Extrapulmonary Tuberculosis (EPPTB)''' is a form of [[tuberculosis]] that occurs outside the [[lungs]]. Although the lungs are the most common site for tuberculosis, the disease can also affect other parts of the body, hence the term "extrapulmonary".
+{{DISPLAYTITLE:Enhanced Permeability and Retention Effect}}
-==Overview==
+== Enhanced Permeability and Retention Effect ==
-[[Tuberculosis]] is a disease caused by the bacterium ''[[Mycobacterium tuberculosis]]''. While it primarily affects the lungs, it can also affect other parts of the body, such as the [[lymph nodes]], [[abdomen]], [[genitourinary system]], [[skin]], [[bones and joints]], and the [[central nervous system]]. When it affects these other parts, it is referred to as '''Extrapulmonary Tuberculosis (EPPTB)'''.
-==Symptoms==
+[[File:EPPTB2DCSD.svg|thumb|right|Diagram illustrating the Enhanced Permeability and Retention Effect]]
-The symptoms of EPPTB depend on the organ system involved but generally include [[fever]], [[weight loss]], and [[night sweats]]. For example, tuberculosis of the spine may result in back pain, while tuberculosis of the kidneys may cause blood in the urine.
-==Diagnosis==
+The '''Enhanced Permeability and Retention (EPR) Effect''' is a phenomenon observed in [[tumor]] biology, where macromolecular drugs and nanoparticles preferentially accumulate in tumor tissue. This effect is primarily due to the unique characteristics of tumor vasculature and the impaired lymphatic drainage in tumors.
-Diagnosis of EPPTB can be challenging as the symptoms are often non-specific and can mimic other diseases. It often involves a combination of [[medical history]], [[physical examination]], [[imaging studies]], and laboratory tests. The definitive diagnosis is made by isolating ''Mycobacterium tuberculosis'' from a sample of tissue or fluid from the affected site.
-==Treatment==
+== Mechanism ==
-Treatment for EPPTB is similar to that for pulmonary tuberculosis and involves a combination of [[antituberculous drugs]]. The duration of treatment may be longer, especially for forms of the disease that are more difficult to treat, such as tuberculosis of the bones and joints.
-==Epidemiology==
+The EPR effect is driven by two main factors:
-EPPTB accounts for approximately 15-20% of all cases of tuberculosis in immunocompetent individuals and up to 50% in those with [[HIV/AIDS]]. It is more common in children and in individuals with a weakened immune system.
-==See Also==
+* '''Enhanced Permeability''': Tumor blood vessels are often irregular, disorganized, and have wide fenestrations. This allows macromolecules and nanoparticles to pass through the vessel walls more easily than in normal tissues.
-* [[Tuberculosis]]
-* [[Pulmonary Tuberculosis]]
-* [[Mycobacterium tuberculosis]]
-* [[Antituberculous drugs]]
-[[Category:Tuberculosis]]
+* '''Retention''': Tumors typically have poor lymphatic drainage, which means that once macromolecules and nanoparticles enter the tumor tissue, they are retained for longer periods.
-[[Category:Infectious diseases]]
-[[Category:Bacterial diseases]]
-{{medicine-stub}}
+These factors together enable the selective accumulation of therapeutic agents in tumor tissues, which can enhance the efficacy of [[cancer]] treatments while minimizing systemic side effects.
+== Applications ==
+The EPR effect is exploited in the design of [[nanomedicine]]s and drug delivery systems. By engineering drugs to be of a certain size and composition, researchers can increase the likelihood that these drugs will accumulate in tumor tissues via the EPR effect. This has led to the development of various [[nanoparticle]]-based therapies and [[liposome]]-encapsulated drugs.
+== Challenges ==
+Despite its potential, the EPR effect is not uniformly effective across all tumor types or patients. Factors such as tumor type, size, location, and the presence of [[hypoxia]] can influence the extent of the EPR effect. Additionally, the heterogeneity of tumor vasculature can lead to variable drug delivery and efficacy.
+== Future Directions ==
+Research is ongoing to better understand the EPR effect and to develop strategies to enhance its effectiveness. Approaches include the use of [[vascular normalization]] agents, [[hyperthermia]], and [[ultrasound]] to improve drug delivery to tumors.
+== Related pages ==
+* [[Tumor microenvironment]]
+* [[Nanoparticle]]
+* [[Drug delivery]]
+* [[Cancer therapy]]
+[[Category:Oncology]]
+[[Category:Pharmacology]]