Image-guided, targeted and triggered drug delivery to tumors using polymer-based microbubbles

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Microbubbles (MB) are established ultrasound contrast agents.
• Current phospholipid-based MB have limitations for stable drug incorporation.
• Polymer-based MB offer potential for enhanced drug delivery applications.

Purpose of the Study:

• To investigate poly(butyl cyanoacrylate) (PBCA)-based hard-shell MB for drug delivery.
• To evaluate drug loading capacity, acoustic properties, and targeted delivery capabilities.
• To assess triggered drug release using ultrasound.

Main Methods:

• Entrapment of hydrophilic and hydrophobic model drugs within PBCA MB shells.
• Characterization of MB acoustic properties post-drug loading.
• Surface functionalization of MB with anti-VEGFR2 antibodies for targeted delivery.
• In vitro and in vivo evaluation of ultrasound-triggered drug release.

Main Results:

• PBCA MB efficiently and stably entrapped both hydrophilic and hydrophobic model drugs.
• Drug loading did not compromise the acoustic properties of the MB.
• Targeted delivery to tumor vasculature was achieved using VEGFR2-functionalized MB.
• High levels of model drug release were observed upon ultrasound disintegration of targeted MB.

Conclusions:

• Polymer-based (PBCA) MB are suitable for stable drug entrapment and controlled release.
• These MB facilitate image-guided, targeted, and triggered drug delivery to tumors.
• PBCA MB represent a promising platform for advanced cancer therapy.