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Oral Delivery (Focus Group – OrD)

ROS-Responsive, Macrophage-Targeted Microparticles for Colon-Specific 5-ASA Delivery

Maria Fernanda Pollini – PhD student, São Paulo State University (UNESP); Augusto Oliveira – Undergraduate student, São Paulo State University (UNESP)
Introduction:

Inflammatory bowel disease requires site-specific delivery of 5-aminosalicylic acid to inflamed colonic tissue. This can be achieved using retrograded starch (RS) and pectin (P), polysaccharides selectively degraded by colonic enzymes (1). Activated macrophages overexpress class A scavenger receptors, enabling dextran sulfate (DS) to direct carriers to inflamed regions (2). Likewise, elevated ROS levels can be exploited to trigger drug release via the ROS-sensitive crosslinker 1,4-phenylenediboronic acid (PDA) (3). This study aimed to develop dual-crosslinked (Al³⁺/PDBA) RS/P/DS microparticles for preferential colonic release of 5-ASA and inflammation-targeted delivery.

Learning Objectives:

  • 1. Explain how dual crosslinking enables gastric protection and ROS-responsive, colon-targeted 5-ASA release.
  • Interpret mucoadhesion, enzyme/ROS-modulated release, and Caco-2 data for site-specific delivery.
  • Describe dextran sulfate-mediated SR-A1 targeting of activated macrophages in inflamed colon.