Determination of the effectiveness of polymeric nanoparticles loaded with mRNA encoding TIMP-3 released from a thermosensitive Poloxamer hydrogel matrix for melanoma treatment

Melanoma, an aggressive neoplasm with a propensity for metastasis, remains challenging to treat because of its rapid progression, high heterogeneity, and resistance to conventional chemotherapeutic agents. In this context, tissue inhibitor of metalloproteinases-3 (TIMP-3) has been shown to exert multifaceted anti-tumor activities through the induction of apoptosis, inhibition of matrix metalloproteinases (MMPs), suppression of angiogenesis, and a marked reduction in melanoma invasiveness, thereby representing a promising molecular target for therapeutic intervention. Previous studies have demonstrated that adenoviral-mediated delivery of TIMP-3 can effectively inhibit tumor formation and growth in vivo through mechanisms that include stabilization of death receptors, thereby sensitizing melanoma cells to apoptotic signals and impairing angiogenesis. Considering the drawbacks of viral vectors, this study employed polymeric nanoparticles (NPs) engineered to encapsulate mRNA encoding TIMP-3, based on cationic poly (beta-amino esters) (PBAEs). Although PBAE NPs have been widely investigated for gene and drug delivery, their integration into a thermosensitive hydrogel matrix has not been reported. The rationale for this combinational approach lies in the complementary functions of the two systems: while the nanoparticles offer robust protection and intracellular delivery of the mRNA encoding TIMP-3, the Poloxamer hydrogel serves as a depot that provides sustained, controlled release at the target site, reduces the frequency of administration, and minimizes systemic exposure and off-target effects. This work not only demonstrates the therapeutic potential of TIMP-3 in melanoma but also provides a novel, modular platform for the localized delivery of mRNA-based therapeutics, with significant implications for advancing personalized cancer treatment.