Composite gels are a type of soft matter, which contains a continuous three-dimensional crosslinked network and has been embedded with non-gel materials. Compared to pure gels, composite gels show high flexibility and tunability in properties and hence have attracted extensive interest in applications ranging from cancer therapy to tissue engineering. In this study, we incorporated triethylenetetramine (TETA)-functionalized cobalt ferrite nanoparticles (ANPs) into a hydrogel consisting of sodium alginate (SA) and methyl cellulose (MC), and examined the resulting composite gels for controlled drug release. The structural, thermal, and morphological aspects of the composite gels were characterized to confirm successful nanoparticle incorporation. Swelling and degradation data demonstrated the pH-responsiveness and enhanced stability of the composite gels. Along with their controlled drug release profiles and their ROS-generating capacity, our composite gels warrant further development as promising bioactive carriers for pharmaceutical applications.