NPC1L1-Targeted Cholesterol-Grafted Poly(β-Amino Ester)/pDNA Complexes for Oral Gene Delivery

Abstract

Gene vectors for oral delivery encounter harsh conditions throughout the gastrointestinal tract, and the continuous peristaltic activity can quickly remove the vectors, leading to inefficient intestinal permeation. Therefore, vectors have demanding property requirements, such as stability under various pH and, more importantly, efficient uptake in different intestinal segments. In this study, a functional polymer, cholesterol-grafted poly(β-amino ester) (poly[hexamethylene diacrylate-β-(5-amino-1-pentanol)] (CH-PHP)), is synthesized and electrostatically interacted with plasmid DNA to form a CH-PHP/DNA complex (CPNC). This complex is designed to target the Niemann-Pick C1-like receptor, a cholesterol receptor, to improve oral gene delivery efficacy. With the presence of cholesterol, CH-PHP shows mitigated cytotoxicity, enhanced enzyme resistance, and improved gene condensing ability. CPNC further contributes to ≈43.1- and 2.3-fold increases in luciferase expression in Caco-2 cells compared with PNC and Lipo 2000/DNA complexes, respectively. In addition, the in vivo transfection efficacy of CPNC is ≈4.1-, 2.1-, and 1.6-fold higher than that of Lipo 2000/DNA complexes in rat duodenum, jejunum, and ileum, respectively. Therefore, CPNC may be a promising delivery vector for gene delivery, and using a cholesterol-specific endocytic pathway can be a novel approach to achieve efficient oral gene transfection.

Keywords: NPC1L1; cellular uptake; cholesterol; oral gene delivery; transfection efficiency.