ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Octa-aminopropyl polyhedral oligomeric silsesquioxane-functionalized magnetic dextran nanoparticles via dynamic Schiff-base imine bonds for sustained doxorubicin release

Ramezan Ali Taheri, Ali Mohammadzadeh, Reza Mohammadi, Ramin Karimian, and Mohammad Reza Khodabakhshi

Nanobiotechnology Research Center, New Health Technologies Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran

E-mail: Khodabakhshi@bmsu.ac.ir

Received: 14 April 2026  Accepted: 10 June 2026

Abstract:

In this study, a pH-responsive drug delivery system (DDS) based on octa-aminopropyl polyhedral oligomeric silsesquioxane (OA-POSS), dextran (Dex), and magnetic nanoparticles (MNPs) was developed for potential cancer therapy applications. Fe₃O₄ NPs were initially synthesized and subsequently functionalized with dextran dialdehyde (Dex-DA) and OA-POSS through a Schiff-base imine reaction, yielding the Fe₃O₄@SiO₂@Dex-DA@OA-POSS nanocarrier (NC). Doxorubicin (DOX), used as a model anticancer agent, was successfully loaded onto the NC via noncovalent physical interactions, achieving a high drug encapsulation efficiency (DEE) of approximately 95%. The synthesized NCs were characterized using FT-IR, FE-SEM, DLS, XRD, and VSM techniques. In vitro drug release studies demonstrated pronounced pH-responsive behavior. At physiological pH (7.4), less than 15% of DOX was released, whereas under acidic conditions (pH 5), approximately 81% of the drug was released over a period 6 days. Cytotoxicity assessments revealed that the blank Fe₃O₄@SiO₂@Dex-DA@OA-POSS NCs were biocompatible with cell viability above 85%. In contrast, DOX-loaded NCs exhibited strong anticancer activity against A549 cells, with an IC₅₀ value of around 1 µg/mL, attributed to the controlled release of DOX. Overall, the Fe₃O₄@SiO₂@Dex-DA@OA-POSS/DOX NC shows promising potential as a targeted and stimuli-responsive drug delivery platform for cancer treatment.

Keywords: Octa-aminopropyl polyhedral oligomeric silsesquioxane; Schiff-base imine reaction; Dextran dialdehyde; pH-sensitive system

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05198-2

Chemical Papers 80 (11) 13563–13578 (2026)