— WHAT IS EXOSOME? —
Extracellular vesicles (EVs) are phospholipid bilayer-enclosed vesicles that are released virtually by all cells. According to the mechanism of their formation EVs can be exosomes or microvesicles. Exosomes are the smaller vesicles (40-120 nm), created by the inward budding of the endosomal membrane. The resulting multivesicular body by the fusion with the cell membrane can relase the exosomes. Microsomes are created by the outward budding of the cell membrane.
Once discharged into the extracellular space, EVs can convey its cargo to reach neighboring or distant cells. When EVs are taken up by the recipient cells, their cargo is believed to alter the physiological and pathological processes of the recipient cells.

Schematic figure of the generation and fate of EVs.
EVs possess several attributes that make them well-suited for direct therapeutic use or as a drug delivery system. EVs exhibit a natural resilience in the circulation which makes them capable to carry a diverse range of molecules, ensuring their delivery to the recipient cells.
Recently we discovered a new mechanism of EVs which makes them capable to treat life-threatening disease. Throughout extensive experiments we proved that instead of delivering proteins to neighboring cells, EVs rather bind and neutralize the effects of some proteins. Nem biztos, hogy akár csak ennyit is le kéne írni.
Such a diseases are the fibroproliferative diseases (FDs) characterised by the activation of fibroblasts and the excessive deposition of extracellular matrix (ECM) in the affected organ leading to the deterioration of its functions. The prevalence FDs is on the rise, posing a significant health concern and accounting for nearly half of all deaths in developed world. Despite the urgent medical demand, the treatment of FDs is significantly limited.
- EXAMPLES FOR FIBROPROLIFERATIVE DISEASES -
Idiopathic pulmonary fibrosis (IPF) is the most aggressive form of interstitial pneumonias resulting in severe respiratory failure and high mortality rate. IPF affects 3 million people worldwide. The aetiology of IPF is unknown, however smoking, infections and genetic variants has been described as risk factors. The progression of IPF is very rapid, even a five-year survival rate can only be reached by lung transplantation. IPF is the only fibroproliferative disease that can be treated with FDA-approved antifibrotic drugs. Although nintedanib or pirfenidone are able to slow down the disease progression, their beneficial effect on long term organ/lung function and survival is insufficient.
The prevalence of chronic kidney disease (CKD) is estimated to be 8-16% worldwide, and is rapidly increasing. The key risk factors of CKD are the chronic "diseases of civilization" including hypertension, diabetes mellitus and autoimmune diseases, but acute kidney injury can also lead to long-term renal damage. CKD is characterized by the excessive deposition of extracellular matrix and gradual loss of kidney function over time. Severe CKD requires renal replacement therapies, like dialysis or kidney transplantation.
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract of genetically susceptible individuals. The main forms are colitis ulcerosa and Crohn's disease. IBD is characterized by impaired mucosal remodeling, leading to intestinal ulceration or fibrosis. The increased submucosal accumulation of extracellular matrix leads to decreased intestinal motility, malabsorption and in severe cases critical narrowing of the lumen. Half of the IBD patients need one or more surgical intervention over their lifetime.