• Exosomes as drug carriers represent a promising approach in the treatment of metastatic cancer
  • Fatemeh Zaree,1,*


  • Introduction: Metastasis is accountable for the majority of cancer-related deaths, making anti-metastasis treatment a potential cornerstone of cancer therapy. Traditional cancer treatments, such as surgery, radiotherapy, and chemotherapy, have limitations, including lack of specific tumor targeting, high toxicity, drug resistance, and adverse physical and mental effects that can significantly impact a patient's quality of life. Consequently, researchers are actively seeking more effective solutions for cancer treatment. In recent years, drug delivery systems utilizing antiparticles, such as polymers and inorganic antiparticles, have been explored as tools for drug delivery, aiming to enhance drug and treatment efficacy while minimizing off-target side effects and drug-related toxicity in cancer. These systems have demonstrated a reduced risk of tumor metastasis compared to conventional treatments. However, they encounter several challenges, including targeting specific organs and addressing the chemical and physical properties linked to toxicity and adverse immune responses. To address these limitations, researchers have shifted their focus to innovative approaches. Exosomes are becoming popular as a potential technique in the field of nanomedicine among various new strategies. Cells secrete minuscule extracellular particles (30–100 nm in size) called exosomes and they are present in body fluids like blood, cerebrospinal fluid, urine, and saliva. They are composed of a lipid bilayer membrane and contain a diverse cargo, including proteins, nucleic acids, and lipids. Exosomes engage in intercellular interactions by exchanging bioactive molecules such as proteins, mRNAs, and miRNAs with recipient cells, thereby influencing cellular functions and signaling pathways. Moreover, the capacity of exosomes to cross the blood-brain barrier (BBB) improves neurological and motor function in the nervous system. This enables the repeated administration of drug-loaded exosomes via intravenous injections without adverse side effects. Exosomes act as vehicles for transferring biomolecules between cells. After being released from donor cells, they can be taken up by recipient cells, allowing proteins, nucleic acids, and lipids to be transferred between cells. This transfer enables the conveyance of signaling molecules and genetic information, which can impact the behavior and characteristics of the recipient cells. Through the activation of signaling pathways, modification of gene expression, and induction of phenotypic alterations, exosomes play a crucial role in modulating the functionality of the target. The increasing popularity of exosomes as a drug delivery strategy for treating cancer metastasis stems from their capacity to address the limitations of conventional therapies. Nevertheless, challenges remain in the clinical application of exosomes.
  • Methods: In recent years, the popularity of exosomes among clinical studies has caused a large number of articles and research works to study the various aspects of exosomes. The assistance of the latest and most beneficial articles on specialized sites such as Elsevier, PubMed, Springer, Nature, and Frontiers was utilized in this article. Our focus will be on the role of exosomes as drug delivery in the treatment of metastasis
  • Results: Recent advances in exosome isolation and analysis reveal their potential as a drug delivery system, creating a protective capsule that transports drugs to disease sites through body fluids. This capsule shields the cargo from degradation, improves stability, and reduces immune response. Engineered exosomes utilize their natural stability, biocompatibility, and low immunogenicity to traverse biological barriers, extending the half-life of chemical drugs compared to synthetic carriers. This method effectively targets metastatic cells, ensuring treatments reach their intended sites with minimal systemic impact.
  • Conclusion: However, exosomes have unique properties, including their small size, that enable them to escape phagocytosis by macrophages and easily pass through the vessel wall and extracellular matrices. Their biocompatibility and ability to target normal proliferation and migration in distant and nearby cells make them potential candidates for the management of metastasis, which involves the spread of cancer cells from the primary tumor site to distant sites. Important challenges remain to be addressed before using exosomes in clinical practice, especially the isolation of exosomes, which is a major obstacle in exosome-based drug delivery. Furthermore, the mechanisms by which exosomes target and enter recipient cells are poorly understood. These limitations have limited the widespread clinical use of exosomes. However, as research advances in understanding exosome function and their interaction with cancer biology, the potential for exosome-based applications in metastatic therapy is becoming increasingly promising, paving the way for more effective cancer therapies.
  • Keywords: Exosomes, drug carriers, Cancer, metastasis