A tactical nanomissile mobilizing antitumor immunity enables neoadjuvant chemo-immunotherapy to minimize postsurgical tumor metastasis and recurrence

Polyphenol-mediated assembly of toll-like receptor 7/8 agonist nanoparticles for effective tumor immunotherapy

Toll-like receptor (TLR) 7/8 agonists have shown significant potential in tumor immunotherapy. However, the limited pharmacokinetic properties and systemic toxicity resulting from off-target effects limits their biomedical applications. We here report the polyphenol-mediated assembly of resiquimod (R848, a TLR7/8 agonist) nanoparticles (RTP NPs) to achieve tumor-selective immunotherapy while avoiding systemic adverse effects. Upon intravenous administration, the prepared RTP NPs are effectively accumulated at tumor sites, which increase their bioavailability and reduce systemic inflammation. RTP NPs can trigger a potent antitumor immune response in a mouse tumor model to inhibit tumor growth. Additionally, after subcutaneous injection at the tail base, RTP NPs efficiently migrate to the lymph nodes, where they elicit immune memory to prevent tumorigenesis. This study underscores the potential application of polyphenol-mediated assembly in developing nanomedicines with reduced toxicity for tumor-specific immunotherapy. STATEMENT OF SIGNIFICANCE: Toll-like receptor agonist (R848) nanoparticles for tumor-selective immunotherapy were synthesized through polyphenol-mediated assembly, a method that simplifies preparation process and minimizes potential side effects. Intravenously administered these nanoparticles effectively extended circulation time, enhanced tumor enrichment, and reduced systemic inflammation, thus augmenting the bioavailability and minimizing the side effects of R848. The nanoparticles significantly inhibited tumor growth by triggering a potent antitumor immune response, including dendritic cell maturation, macrophage polarization, T-cell infiltration, and cytokine secretion. Moreover, after subcutaneous injection at the tail base, they can elicit immune memory to prevent tumorigenesis.

A hierarchically acidity-unlocking nanoSTING stimulant enables cascaded STING activation for potent innate and adaptive antitumor immunity

Rationale: Neoadjuvant chemotherapy (NAC) has been recognized as an indispensable strategy for advanced malignancies. Nevertheless, the enhancement of overall patient survival in NAC recipients has encountered challenges due to the limited sustainability of its efficacy and the inability to prevent postoperative tumor recurrence and metastasis. Methods: We devise a hierarchically unlocking nanoSTING stimulant liposome (AUG) as a neoadjuvant chemoimmunotherapy agent in the debulking of tumors prior to surgery and prevention of postoperative tumor recurrence and metastasis by simultaneously activating innate and adaptive antitumor immune responses. In the weakly acidic tumor microenvironment, the hydrazone bond within AUG is initially cleaved, leading to the release of a cyclic seven-membered ring containing tertiary amine that serve to activate the stimulator of interferon genes (STING) pathway. Following this, AUG undergoes degradation within lysosomes, facilitating the release of doxorubicin and ultimately inducing immunogenic cell death along with leakage of double-stranded DNA into the cytoplasm. Results: The hierarchically acidity-unlocking pattern enables cascaded STING activation, achieving over 90% tumor growth inhibition in subcutaneous xenograft model and preventing 75% of mice from postsurgical metastasis or recurrence when combined with immune checkpoint inhibitors. Conclusion: Our strategy highlights the potency of AUG as a neoadjuvant paradigm for presurgical tumor debulking and as a preventive measure against postoperative tumor recurrence and metastasis.

GSH-responsive polymeric micelles-based augmented photoimmunotherapy synergized with PD-1 blockade for eliciting robust antitumor immunity against colon tumor

Phototherapy is a promising antitumor modality, which consists of photothermal therapy (PTT) and photodynamic therapy (PDT). However, the efficacy of phototherapy is dramatically hampered by local hypoxia in tumors, overexpression of indoleamine 2,3-dioxygenase (IDO) and programmed cell death ligand-1 (PD-L1) on tumor cells. To address these issues, self-assembled multifunctional polymeric micelles (RIMNA) were developed to co-deliver photosensitizer indocyanine green (ICG), oxygenator MnO2, IDO inhibitor NLG919, and toll-like receptor 4 agonist monophosphoryl lipid A (MPLA). It is worth noting that RIMNA polymeric micelles had good stability, uniform morphology, superior biocompatibility, and intensified PTT/PDT effect. What's more, RIMNA-mediated IDO inhibition combined with programmed death receptor-1 (PD-1)/PD-L1 blockade considerably improved immunosuppression and promoted immune activation. RIMNA-based photoimmunotherapy synergized with PD-1 antibody could remarkably inhibit primary tumor proliferation, as well as stimulate the immunity to greatly suppress lung metastasis and distant tumor growth. This study offers an efficient method to reinforce the efficacy of phototherapy and alleviate immunosuppression, thereby bringing clinical benefits to cancer treatment.

Reversing cancer immunoediting phases with a tumor-activated and optically reinforced immunoscaffold

In situ vaccine (ISV) is a promising immunotherapeutic tactic due to its complete tumoral antigenic repertoire. However, its efficiency is limited by extrinsic inevitable immunosuppression and intrinsic immunogenicity scarcity. To break this plight, a tumor-activated and optically reinforced immunoscaffold (TURN) is exploited to trigger cancer immunoediting phases regression, thus levering potent systemic antitumor immune responses. Upon response to tumoral reactive oxygen species, TURN will first release RGX-104 to attenuate excessive immunosuppressive cells and cytokines, and thus immunosuppression falls and immunogenicity rises. Subsequently, intermittent laser irradiation-activated photothermal agents (PL) trigger abundant tumor antigens exposure, which causes immunogenicity springs and preliminary infiltration of T cells. Finally, CD137 agonists from TURN further promotes the proliferation, function, and survival of T cells for durable antitumor effects. Therefore, cancer immunoediting phases reverse and systemic antitumor immune responses occur. TURN achieves over 90 % tumor growth inhibition in both primary and secondary tumor lesions, induces potent systemic immune responses, and triggers superior long-term immune memory in vivo. Taken together, TURN provides a prospective sight for ISV from the perspective of immunoediting phases.

Antigenicity and adjuvanticity co-reinforced personalized cell vaccines based on self-adjuvanted hydrogel for post-surgical cancer vaccination

Cancer vaccine-based postsurgical immunotherapy is emerging as a promising approach in patients following surgical resection for inhibition of tumor recurrence. However, low immunogenicity and insufficient cancer antigens limit the widespread application of postoperative cancer vaccines. Here, we propose a "trash to treasure" cancer vaccine strategy to enhance postsurgical personalized immunotherapy, in which antigenicity and adjuvanticity of purified surgically exfoliated autologous tumors (with whole antigen repertoire) were co-reinforced. In the antigenicity and adjuvanticity co-reinforced personalized vaccine (Angel-Vax), polyriboinosinic: polyribocytidylic acid (pIC) and tumor cells that have undergone immunogenic death are encapsulated in a self-adjuvanted hydrogel formed by cross-linking of mannan and polyethyleneimine. Angel-Vax exhibits an enhanced capacity on antigen-presenting cells stimulation and maturation compared to its individual components in vitro. Immunization with Angel-Vax provokes an efficient systemic cytotoxic T-cell immune response, contributing to the satisfied prophylactic and therapeutic efficacy in mice. Furthermore, when combined with immune checkpoint inhibitors (ICI), Angel-Vax effectively prevented postsurgical tumor recurrence, as evidenced by an increase in median survival of approximately 35% compared with ICI alone. Unlike the cumbersome preparation process of postoperative cancer vaccines, the simple and feasible approach herein may represent a general strategy for various kinds of tumor cell-based antigens in the inhibition of postsurgical tumor relapse by reinforced immunogenicity.

Chemotherapy-induced metastasis: molecular mechanisms and clinical therapies

Chemotherapy, the most widely accepted treatment for malignant tumors, is dependent on cell death induced by various drugs including antimetabolites, alkylating agents, mitotic spindle inhibitors, antitumor antibiotics, and hormonal anticancer drugs. In addition to causing side effects due to non-selective cytotoxicity, chemotherapeutic drugs can initiate and promote metastasis, which greatly reduces their clinical efficacy. The knowledge of how they induce metastasis is essential for developing strategies that improve the outcomes of chemotherapy. Herein, we summarize the recent findings on chemotherapy-induced metastasis and discuss the underlying mechanisms including tumor-initiating cell expansion, the epithelial-mesenchymal transition, extracellular vesicle involvement, and tumor microenvironment alterations. In addition, the use of combination treatments to overcome chemotherapy-induced metastasis is also elaborated.

Cancer nanomedicine in preoperative therapeutics: Nanotechnology-enabled neoadjuvant chemotherapy, radiotherapy, immunotherapy, and phototherapy

Surgical resection remains a mainstay in the treatment of malignant solid tumors. However, the use of neoadjuvant treatments, including chemotherapy, radiotherapy, phototherapy, and immunotherapy, either alone or in combination, as a preoperative intervention regimen, have attracted increasing attention in the last decade. Early randomized, controlled trials in some tumor settings have not shown a significant difference between the survival rates in long-term neoadjuvant therapy and adjuvant therapy. However, this has not hampered the increasing use of neoadjuvant treatments in clinical practice, due to its evident downstaging of primary tumors to delineate the surgical margin, tailoring systemic therapy response as a clinical tool to optimize subsequent therapeutic regimens, and decreasing the need for surgery, with its potential for increased morbidity. The recent expansion of nanotechnology-based nanomedicine and related medical technologies provides a new approach to address the current challenges of neoadjuvant therapy for preoperative therapeutics. This review not only summarizes how nanomedicine plays an important role in a range of neoadjuvant therapeutic modalities, but also highlights the potential use of nanomedicine as neoadjuvant therapy in preclinical and clinic settings for tumor management.

Nanomaterial-Based Antivascular Therapy in the Multimodal Treatment of Cancer

Abnormal tumor vasculature and a hypoxic tumor microenvironment (TME) limit the effectiveness of conventional cancer treatment. Recent studies have shown that antivascular strategies that focus on antagonizing the hypoxic TME and promoting vessel normalization effectively synergize to increase the antitumor efficacy of conventional therapeutic regimens. By integrating multiple therapeutic agents, well-designed nanomaterials exhibit great advantages in achieving higher drug delivery efficiency and can be used as multimodal therapy with reduced systemic toxicity. In this review, strategies for the nanomaterial-based administration of antivascular therapy combined with other common tumor treatments, including immunotherapy, chemotherapy, phototherapy, radiotherapy, and interventional therapy, are summarized. In particular, the administration of intravascular therapy and other therapies with the use of versatile nanodrugs is also described. This review provides a reference for the development of multifunctional nanotheranostic platforms for effective antivascular therapy in combined anticancer treatments.