Dynamic nanoassemblies derived from small-molecule homodimeric prodrugs for in situ drug activation and safe osteosarcoma treatment

A comprehensive review on the latest advances of dimeric anticancer prodrugs

The advancement of targeted drug delivery systems has opened up a wide array of opportunities in cancer therapy, leading to the exploration of various strategies. Among these, the use of prodrugs stands out as a particularly promising approach in targeted cancer treatment, aimed at enhancing the selectivity and effectiveness of cytotoxic agents. In the last few years, there has been considerable progress in the area of dimeric-based prodrugs aimed at cancer therapy. The advantages presented by dimeric-based prodrugs have significantly improved the efficiency of delivering anticancer drugs, characterized by a high drug loading capacity, advantageous pharmacokinetics, and drug release that responds to tumor stimuli. With respect to the importance of drug dimerization in the field of prodrug development, herein we review the latest reports covering research in dimeric prodrugs. We have categorized the article according to the reported anticancer agents. We have also spent a great deal of attention on different types of used linkers and methods of the dissociation of dimeric prodrugs into free monomeric drugs. Readers will easily be able to compare between the reported research using the same drugs with different linkers or different dissociation methods as well as different cancer cell lines targeted in the studies.

Revealing the impact of modified modules flexibility on gemcitabine prodrug nanoassemblies for effective cancer therapy

Prodrug nanoassemblies combine the advantages of prodrug strategies and nanotechnology have been widely utilized for delivering antitumor drugs. These prodrugs typically comprise active drug modules, response modules, and modification modules. Among them, the modification modules play a critical factor in improving the self-assembly ability of the parent drug. However, the impact of the specific structure of the modification modules on prodrug self-assembly remains elusive. In this study, two gemcitabine (GEM) prodrugs are developed using 2-octyl-1-dodecanol (OD) as flexible modification modules and cholesterol (CLS) as rigid modification modules. Interestingly, the differences in the chemical structure of modification modules significantly affect the assembly performance, drug release, cytotoxicity, tumor accumulation, and antitumor efficacy of prodrug nanoassemblies. It is noteworthy that the prodrug nanoassemblies constructed with flexible modifying chains (OD) exhibit improved stability, faster drug release, and enhanced antitumor effects. Our findings elucidate the significant impact of modification modules on the construction of prodrug nanoassemblies.

Advancements in osteosarcoma management: integrating immune microenvironment insights with immunotherapeutic strategies

Osteosarcoma, a malignant bone tumor predominantly affecting children and adolescents, presents significant therapeutic challenges, particularly in metastatic or recurrent cases. Conventional surgical and chemotherapeutic approaches have achieved partial therapeutic efficacy; however, the prognosis for long-term survival remains bleak. Recent studies have highlighted the imperative for a comprehensive exploration of the osteosarcoma immune microenvironment, focusing on the integration of diverse immunotherapeutic strategies-including immune checkpoint inhibitors, tumor microenvironment modulators, cytokine therapies, tumor antigen-specific interventions, cancer vaccines, cellular therapies, and antibody-based treatments-that are directly pertinent to modulating this intricate microenvironment. By targeting tumor cells, modulating the tumor microenvironment, and activating host immune responses, these innovative approaches have demonstrated substantial potential in enhancing the effectiveness of osteosarcoma treatments. Although most of these novel strategies are still in research or clinical trial phases, they have already demonstrated significant potential for individuals with osteosarcoma, suggesting the possibility of developing new, more personalized and effective treatment options. This review aims to provide a comprehensive overview of the current advancements in osteosarcoma immunotherapy, emphasizing the significance of integrating various immunotherapeutic methods to optimize therapeutic outcomes. Additionally, it underscores the imperative for subsequent research to further investigate the intricate interactions between the tumor microenvironment and the immune system, aiming to devise more effective treatment strategies. The present review comprehensively addresses the landscape of osteosarcoma immunotherapy, delineating crucial scientific concerns and clinical challenges, thereby outlining potential research directions.

Amicis Omnia Sunt Communia: NF-κB Inhibition as an Alternative to Overcome Osteosarcoma Heterogeneity

Tumor heterogeneity poses a significant challenge in osteosarcoma (OS) treatment. In this regard, the "omics" era has constantly expanded our understanding of biomarkers and altered signaling pathways (i.e., PI3K/AKT/mTOR, WNT/β-catenin, NOTCH, SHH/GLI, among others) involved in OS pathophysiology. Despite different players and complexities, many commonalities have been described, among which the nuclear factor kappa B (NF-κB) stands out. Its altered activation is pervasive in cancer, with pleiotropic action on many disease-relevant traits. Thus, in the scope of this article, we highlight the evidence of NF-κB dysregulation in OS and its integration with other cancer-related pathways while we summarize the repertoire of compounds that have been described to interfere with its action. In silico strategies were used to demonstrate that NF-κB is closely coordinated with other commonly dysregulated signaling pathways not only by functionally interacting with several of their members but also by actively participating in the regulation of their transcription. While existing inhibitors lack selectivity or act indirectly, the therapeutic potential of targeting NF-κB is indisputable, first for its multifunctionality on most cancer hallmarks, and secondly, because, as a common downstream effector of the many dysregulated pathways influencing OS aggressiveness, it turns complex regulatory networks into a simpler picture underneath molecular heterogeneity.

Tetrasulfide bond boosts the anti-tumor efficacy of dimeric prodrug nanoassemblies

Dimeric prodrug nanoassemblies (DPNAs) stand out as promising strategies for improving the efficiency and safety of chemotherapeutic drugs. The success of trisulfide bonds (-SSS-) in DPNAs makes polysulfide bonds a worthwhile focus. Here, we explore the comprehensive role of tetrasulfide bonds (-SSSS-) in constructing superior DPNAs. Compared to trisulfide and disulfide bonds, tetrasulfide bonds endow DPNAs with superlative self-assembly stability, prolonged blood circulation, and high tumor accumulation. Notably, the ultra-high reduction responsivity of tetrasulfide bonds make DPNAs a highly selective "tumor bomb" that can be ignited by endogenous reducing agents in tumor cells. Furthermore, we present an "add fuel to the flames" strategy to intensify the reductive stress at tumor sites by replenishing exogenous reducing agents, making considerable progress in selective tumor inhibition. This work elucidates the crucial role of tetrasulfide bonds in establishing intelligent DPNAs, alongside the combination methodology, propelling DPNAs to new heights in potent cancer therapy.