Recent updates in alginate as a promising biopolymer in cancer therapy: A review

Alginate-based hydrogels, nanoparticles, and composite delivery systems have emerged as adaptable platforms for cancer therapy when their efficacy is led by rational management of polymer structure and modification technique, according to recent research conducted between 2020 and 2025. To customize drug loading capacity, release kinetics, tumor-responsive behavior, and biological activity, this review focuses exclusively on the intentional tuning of alginate block composition (M/G ratio and block distribution), molecular weight, and physical, chemical, or biological modifications. The review critically investigates the structure-property-function linkages that control therapeutic results across localized and systemic delivery platforms, as opposed to offering a solely descriptive summary of formulation types. The development of multifunctional systems that combine chemotherapy with photothermal, antiangiogenic, or immunomodulatory effects while reducing off-target toxicity, improved solubility and stability of hydrophobic anticancer agents, and pH- and redox-responsive drug release in tumor-like microenvironments are all discussed in relation to alginate-based carriers. Across recent studies, alginate-based carriers consistently achieve high drug encapsulation efficiencies (typically 60-95%), pH- or stimulus-responsive release with up to 65-90% drug liberation under tumor-like conditions and marked biological gains, including 2-12-fold reductions in IC₅₀ values compared to free drugs. These improvements are mechanistically associated with enhanced apoptotic signaling (e.g., Bax, p53, caspase-3/9 activation) and suppression of proliferative and metastatic pathways, underscoring the functional advantages of rational alginate design. Beyond identifying critical limitations, this review frames batch variability, long-term safety, and translational barriers through a structure-property-performance lens, highlighting design parameters and evaluation strategies that support reproducibility, scalability, and regulatory readiness. By integrating comparative metrics and mechanistic insights, the review guides rational optimization of alginate-based systems to accelerate their progression toward clinical application.