Epirubicin-loaded porous wollastonite nanoparticles for colorectal cancer therapy: synthesis, characterization, and in vivo study

Epirubicin is an effective anthracycline chemotherapeutic agent, yet its clinical utility is restricted by dose-dependent toxicity and poor tumor selectivity. To address these limitations, this study investigates porous wollastonite nanoparticles (PWNs) as nanocarriers for Epirubicin delivery in colorectal cancer therapy. porous wollastonite nanoparticles with tailored pore architectures—microporous (W1), mesoporous (W2), and micro-mesoporous (W3)—were synthesized and characterized for morphology, surface charge, particle size, and drug loading efficiency. Drug release behavior was assessed under physiological (pH 7.4) and acidic (pH 5.5) conditions. In vitro cytotoxicity, cellular uptake, and IC₅₀ values were evaluated in C26 colon carcinoma cells. In vivo efficacy, biodistribution, and biocompatibility were assessed in Balb/c mice bearing C26 tumors. Epirubicin loading efficiency exceeded 98 % in all formulations. Epirubicin released at pH 5.5 was approximately 3.2–4.2 times greater than pH 7.4. Epi-W1 exhibited superior in vitro cytotoxicity and cellular uptake compared to other formulations. Among the formulations, Epi-W3 demonstrated the greatest tumor suppression, extended survival, and minimal systemic toxicity. This superior performance is attributed to its hierarchical micro–mesoporous architecture, which enabled both efficient drug loading and balanced pH-responsive release, thereby enhancing tumor accumulation and therapeutic efficacy. Biodistribution studies confirmed preferential tumor accumulation of Epi-W3 with reduced other organ exposure. Epirubicin-loaded porous wollastonite nanoparticles, especially the Epi-W3 formulation, offer a promising platform for passive-targeted colorectal cancer therapy. Their ability to enhance tumor delivery while minimizing systemic toxicity highlights their potential for clinical translation.