Dual crosslinked interpenetrating polymer network (IPN) beads of sodium alginate reinforced with curdlan-grafted poly-N-isopropylacrylamide/montmorillonite [Cud-g-PNIPA-/MMT] nanocomposites were accomplished for effective delivery of erlotinib HCl (ERL) to triple-negative breast cancer (TNBC) cells. Different beads exhibited variable size (1.30–1.47 mm) and excellent drug entrapment efficiency (DEE, 49.35–93.01%), which were influenced by the contents of reinforcing clay (MMT) in the composites. The SEM photographs also displayed the spherical morphology of the beads, and the results of infrared, thermal, and X-ray diffraction studies conferred a compatible environment of ERL in the matrices. Moreover, the sustained drug release profiles (Q_8h, 73.79–84.24%) of various matrices were best fitted in the Korsmeyer-Peppas kinetic model with Fickian diffusion-driven mechanism. Furthermore, the beads demonstrated temperature-responsive swelling behavior and their molar masses between crosslinks (\(\bar{M}\)_c) estimated by Flory-Rehner equation were enhanced with temperature. The beads containing 20% MMT (F-3) displayed a faster biodegradability than the control matrices (F-1, 0% MMT). The mucin adsorption ability of F-1 and F-3 followed Freundlich isotherm and Langmuir isotherm, respectively. As compared to pristine drug, F-3 bestowed an increased sensitivity on MDA-MB-231 cells. Thus, the Cud/alginate IPN beads could be employed as efficient drug carriers for TNBC therapy.