TITLE:
Preclinical Validation of ZF-148-2 Nanodrug for Breast Cancer: Antitumor Efficacy, Survival Benefit, and Histopathological Safety in the 4T1 Murine Model
AUTHORS:
Zahra Fakhroueian, Marzieh Eghtedardoost, Alireza Massiha, Fereshteh Abbasvandi
KEYWORDS:
Preclinical Study, Breast Cancer, 4T1 Murine Model, BALB/c Mice, ZF-148-2 Nanodrug, ZnO Quantum Dots, Antitumor Efficacy, Tumor Growth Inhibition, Survival, Histopathology, Nanomedicine, Clinical Development
JOURNAL NAME:
Advances in Nanoparticles,
Vol.15 No.4,
November
6,
2026
ABSTRACT: Background: Triple-negative breast cancer (TNBC) is characterized by aggressive growth, early metastasis, and limited targeted therapeutic options. Our research on the ZnO quantum dot-based nanodrug was initially conducted using the first formulation, ZF-148, which was evaluated both in vitro in the 4T1 breast cancer cell line and in vivo in animal models using both oral and injectable administration approaches. The initial preclinical findings were published in 2022, and the formulation was subsequently protected by a patent. Following these initial findings, the preclinical investigation was continued through additional animal studies designed to obtain further evidence of antitumor activity, survival benefit, and histopathological effects. In the subsequent stage of this research program, the formulation was designated ZF-148-2 for the current series of preclinical studies. Thus, ZF-148 and ZF-148-2 refer to the same underlying therapeutic formulation and represent successive stages of its preclinical investigation rather than different drug formulations. The present study reports recent findings obtained with ZF-148-2, particularly in the 4T1 murine breast cancer model, with the aim of further expanding the preclinical evidence base and supporting the continued translational development of this nanodrug toward clinical evaluation for breast cancer. Methods: The cytotoxic effect of ZF-148-2 was assessed in MCF-7 breast cancer cells using the MTT assay after 48 h of treatment. For the in vivo study, 1 × 106 4T1 cells were inoculated subcutaneously into the flank of female BALB/c mice. Tumor-bearing animals were allocated to a vehicle control group (n = 4) or a ZF-148-2 treatment group receiving 70 mg/kg by intratumoral injection every other day (n = 6). Tumor dimensions, clinical condition, and survival were monitored throughout the study. Tumors and major organs were subsequently examined histopathologically using hematoxylin and eosin staining. Results: In the recent preclinical studies of ZF-148-2, the nanodrug demonstrated concentration-dependent cytotoxic activity against breast cancer cells, with an estimated IC₅₀ of approximately 4.0 mg/L. Tumor growth was markedly suppressed in treated mice. The mean individual tumor growth rate decreased from 0.491 ± 0.043 mm2/day in the control group to 0.040 ± 0.068 mm2/day in the treatment group (P Conclusion: Intratumoral administration of ZF-148-2 produced a pronounced antitumor effect in the 4T1 murine breast cancer model, as demonstrated by a highly significant reduction in tumor growth rate and a substantial extension of survival. The marked architectural destruction and extensive necrotic changes observed in treated tumors, together with the preservation of normal histological architecture in the examined major organs, provide complementary evidence of therapeutic activity without detectable major-organ toxicity under the conditions of this study. These findings demonstrate a favorable therapeutic profile of ZF-148-2 in this aggressive breast cancer model and substantially strengthen the current preclinical evidence supporting its continued development. Further adequately powered studies addressing dose-response relationships, pharmacokinetics, biodistribution, direct mechanistic validation, and local injection-site safety will be important to define the translational profile of the nanodrug and support its progression toward clinical evaluation for breast cancer.