Intravital microscopic research of microembolization with degradable starch microspheres

Area of Science:

• Biomedical Engineering
• Oncology
• Pharmacology

Background:

• Systemic cytostatic drug efficacy in cancer is limited by cytotoxic side effects, necessitating localized delivery methods.
• Transarterial chemoembolization (TACE) aims to increase drug concentration at the tumor site while minimizing systemic exposure.
• Effective embolization materials are crucial for successful TACE, requiring controlled drug release and minimal adverse effects.

Purpose of the Study:

• To evaluate the efficacy of degradable starch microspheres (DSM) as an embolization material for enhancing 5-fluorouracil (5-FU) accumulation in liver tumors.
• To assess the hemorheological effects and degradation profile of DSM in the context of liver cancer treatment.
• To compare the safety and tolerability of DSM-mediated TACE with other embolization materials, focusing on the incidence of postembolization syndrome.

Main Methods:

• In vivo studies using experimental liver cancer induced in rats.
• Application of 5-FU loaded DSM into the feeding blood vessels of liver tumors.
• Intravital microscopy to observe immediate changes in blood flow dynamics.
• Monitoring the degradation of DSM and its impact on vascular patency over time.
• Assessment of adverse effects, including postembolization syndrome.

Main Results:

• DSM application led to rapid deceleration of blood flow into the target liver tumor.
• Significant accumulation and enhanced concentration of 5-FU within the liver tumor tissue were observed.
• DSM exhibited stepwise degradation, completely dissolving within 25 minutes.
• Temporary and reciprocal blood flow through side-arms occurred during DSM degradation.
• TACE using DSM resulted in a rare occurrence of severe adverse effects like postembolization syndrome compared to other materials.

Conclusions:

• Degradable starch microspheres are a highly effective embolization material for TACE, significantly enhancing drug delivery to liver tumors.
• The controlled degradation and temporary vascular occlusion by DSM minimize adverse effects, offering a safer alternative to conventional embolization agents.
• The short-lasting vascular occlusion allows for repeat TACE applications, potentially improving long-term treatment outcomes in liver cancer.