pH-responsive magnetic carboxymethyl cellulose/sodium alginate hydrogel beads for controlled release of tetracycline hydrochloride

The exploration of novel drug delivery systems that respond to environmental changes has been motivating researchers to design smart biomaterials. Herein, we synthesized novel CMC-SA-Fe 3 O 4 hydrogel beads with dual responsiveness (pH- and magnetic), which were composed of low-cost and biocompatible carboxymethyl cellulose (CMC), sodium alginate (SA), and Fe 3 O 4 nanoparticles (NPs), and could serve as a delivery platform for model drug (tetracycline hydrochloride, TCH). In vitro drug release profiles confirmed these beads exhibited exceptional stability at pH 1.8, with cumulative drug release reaching 50.5 % (pH 6.8) and 60.7 % (pH 7.8) in alkaline media following the Ritger-Peppas model, and notably, external magnetic field (EMF) significantly accelerated TCH release. Additionally, bacteriostatic assays demonstrated that the synthesized beads had sufficient antibacterial activity against both Gram-negative ( Escherichia coli, E. coli ) and Gram-positive ( Staphylococcus aureus, S. aureus ) bacteria. In vitro, cytotoxicity tests showed that the gel beads had no deleterious effects on normal liver cells (HL-7702) but showed significant cytotoxicity against hepatocellular carcinoma cells (HePG2). This work explores a rapid, simple, and economical method for preparing hydrogel beads without the use of any hazardous chemicals as reducing agents or stabilizers. In addition, this novel pH/magnetically responsive, biocompatible, antibacterial, and antitumor platform will play an important role in the biomedical field. • Novel pH-responsive magnetic carboxymethyl cellulose/sodium alginate hydrogel beads were prepared. • The tetracycline release kinetic obeyed the Ritger-Peppas model. • The beads showed sufficient antibacterial activity against both E. coli and S. aureus bacteria. • The beads had no adverse effects on normal liver cells (HL-7702), but exhibited significant cytotoxicity against liver cancer cells (HePG2).