▎ 摘　　要

New composite microbeads were formulated as smart pH-sensitive vehicle for efficient delivery of ciprofloxacin (CIP) drug. Herein, carboxylated graphene oxide (CGO) was successfully impregnated into alginate (Alg) microbeads, which were then coated with aminated chitosan (AmCs) layer to form core-shell Alg/CGO@AmCs composite microbeads. Diverse analysis tools comprising FTIR, TGA, XRD and SEM were employed to characterize the developed carriers, while their swelling profiles and pH-sensitivity were examined under different pHs. The results clar-ified that increasing CGO and AmCs concentrations in microbeads matrix greatly protected Alg microbeads from fast disintegration at colon pH and prolonged their swelling time. Moreover, about 94.65 % of CIP drug was successfully loaded by Alg/CGO@AmCs composite microbeads compared to 61.95 % for Alg microbeads, confirming their reduced porosity. The in vitro CIP-release profiles were investigated in simulated gastrointestinal conditions. Furthermore, increasing AmCs concentration in the outer shell of composite microbeads clearly minimized the CIP burst release at the colon region and offered a sustained release performance. Besides, the CIP release mechanism was well-described by korsmeyer-peppas kinetic model. The cytotoxicity study con-firmed the potential safety of the Alg/CGO@AmCs composite microbeads with human cell viability reached 98.98 %, suggesting their applicability as smart carriers for oral delivery of antibiotics.(c) 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).