Redox imbalance and epigenetic dysregulation, which both contribute to tumor initiation, survival, and resistance to therapy, are intimately linked to the progression of cancer. Reactive oxygen species (ROS) have two contrasting effects: at moderate concentrations, they promote angiogenesis and oncogenic signaling, whereas at high concentrations, they trigger apoptosis. Oxidative stress alters histone modifications, DNA methylation, and non-coding RNA (ncRNA) expression, reshaping the epigenetic landscape and supporting malignant phenotypes. Plant-derived antioxidants, including flavonoids, polyphenols, alkaloids, and terpenoids, act as dual modulators of cancer biology. They scavenge or regulate reactive oxygen species (ROS), restore redox balance, activate tumor suppressor pathways, inhibit oncogenic mechanisms, and reverse abnormal epigenetic marks. Compounds such as resveratrol, curcumin, epigallocatechin gallate (EGCG), quercetin, and sulforaphane modulate DNA methyltransferases (DNMTs), histone deacetylases (HDACs), and non-coding RNA networks, and can enhance chemotherapy and radiation therapy. Despite promising mechanisms, challenges remain in translational efficacy, optimal dosing, and bioavailability. This review emphasizes the potential of plant-derived antioxidants as precision oncology adjuncts and highlights the need for biomarker-guided strategies, nano-delivery systems, and clinical validation to fully realize their therapeutic benefits. Plant-derived antioxidants mitigate ROS-induced oncogenic signaling, as evidenced by in vitro and clinical models.

Three-dimensional (3D) bioprinting has rapidly evolved into a controlling platform for the fabrication of patient-specific biomedical implants, with growing importance in advanced drug delivery systems. Beyond structural tissue engineering, bioprinted constructs now function as programmable therapeutic depots capable of localized, sustained, and stimuli-responsive drug release. This review focuses on recent biomaterial design strategies that enable precise control over drug encapsulation, retention, and release kinetics within 3D bioprinted architectures. The physicochemical and mechanical properties of bioinks, including crosslinking density, porosity, degradation behavior, viscoelasticity, and swelling characteristics, directly influence drug loading efficiency and release dynamics under physiological conditions. The rational tuning of these parameters allows the development of constructs that provide spatially controlled and temporally regulated therapeutic delivery. Recent advances in predictive modeling, such as finite element modeling (FEM), data-driven machine learning approaches, and ML, have significantly improved the ability to correlate material composition, printing parameters, and structural geometry with drug diffusion and degradation-mediated release mechanisms. These tools facilitate the optimization of printing variables including extrusion pressure, nozzle diameter, and layer resolution to ensure structural fidelity while maintaining therapeutic functionality. Emerging strategies incorporating multi-material printing, gradient architectures, and stimuli-responsive biomaterials have expanded the potential of 3D bioprinting for combination therapies and personalized medicine. This review discusses key challenges in translating bioprinted drug delivery systems into clinical applications, including the standardization of drug release characterization methods, and long-term stability assessment.