Minimalist Nanocomplex with Dual Regulation of Endothelial Function and Inflammation for Targeted Therapy of Inflammatory Vascular Diseases.

Vascular disorders, characterized by vascular endothelial dysfunction combined with inflammation, are correlated with numerous fatal diseases, such as coronavirus disease-19 and atherosclerosis. Achieving vascular normalization is an urgent problem that must be solved when treating inflammatory vascular diseases. Inspired by the vascular regulatory versatility of nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) catalyzing l-arginine (l-Arg), the eNOS-activating effects of l-Arg, and the powerful anti-inflammatory and eNOS-replenishing effects of budesonide (BUD), we constructed a bi-prodrug minimalist nanoplatform co-loaded with BUD and l-Arg via polysialic acid (PSA) to form BUD-l-Arg@PSA. This promoted vascular normalization by simultaneously regulating vascular endothelial dysfunction and inflammation. Mediated by the special affinity between PSA and E-selectin, which is highly expressed on the surface of activated endothelial cells (ECs), BUD-l-Arg@PSA selectively accumulated in activated ECs, targeted eNOS expression and activation, and promoted NO production. Consequently, the binary synergistic regulation of the NO/eNOS signaling pathway occurred and improved vascular endothelial function. NO-induced nuclear factor-kappa B alpha inhibitor (IκBα) stabilization and BUD-induced nuclear factor-kappa B (NF-κB) response gene site occupancy achieved dual-site blockade of the NF-κB signaling pathway, thereby reducing the inflammatory response and inhibiting the infiltration of inflammation-related immune cells. In a renal ischemia-reperfusion injury mouse model, BUD-l-Arg@PSA reduced acute injury. In an atherosclerosis mouse model, BUD-l-Arg@PSA decreased atherosclerotic plaque burden and improved vasodilation. This represents a revolutionary therapeutic strategy for inflammatory vascular diseases.

Polysialic Acid Self-assembled Nanocomplexes for Neutrophil-Based Immunotherapy to Suppress Lung Metastasis of Breast Cancer.

The role of neutrophils in tumor metastasis has recently attracted widespread interest. Neutrophils are the most abundant immune cells in human peripheral blood, and large numbers can spontaneously migrate to metastatic sites, where they form an immunosuppressive microenvironment. Polysialic acid (PSA) can target peripheral blood neutrophils (PBNs) mediated by L-selectin, and abemaciclib (ABE) and mitoxantrone (MIT) can treat immunosuppressive microenvironments. Here, we aimed to inhibit lung metastasis of breast cancer and improve chemoimmunotherapy by designing a PSA-modified ABE and MIT co-delivery system (AM-polyion complex (PIC)) to target PBNs in mice with metastatic tumors. We found that through electrostatic interactions between the strong negative charge of PSA and the positive charge of the drug can form stable nanocomplexes and that spontaneous migration of neutrophils can mediate the aggregation of these complexes in the lungs, induce antimetastatic immune responses, enhance the effectiveness of cytotoxic T lymphocytes (CTLs), and inhibit regulatory T cell (Treg) proliferation in vivo and in vitro. Pharmacodynamic results suggested that neutrophil-mediated AM-PIC chemoimmunotherapy inhibited tumor metastasis in mice with lung metastasis of 4T1 breast cancer. Overall, PSA-modified nanocomplexes offer promising neutrophil-mediated, targeted drug delivery systems to treat lung metastasis of breast cancer.

Neutrophils as emerging immunotherapeutic targets: Indirect treatment of tumors by regulating the tumor immune environment based on a sialic acid derivative-modified nanocomplex platform.

Tumor cells are dependent on their microenvironment; thus, targeting the non-cancerous components surrounding the tumor may be beneficial. Neutrophils are important inflammatory cells in the tumor microenvironment that significantly affect tumor cell proliferation, metastasis, and immune regulation. Targeted regulation of tumor-associated neutrophil-related pathways is expected to become a new therapeutic approach. Colchicine compounds are powerful anti-inflammatory drugs that strongly inhibit the chemotaxis of neutrophils to the inflammatory site. We attempted to achieve anticancer effects by utilizing its ability to inhibit neutrophil recruitment rather than killing tumor cells. As such drugs are likely to cause non-specific damages due to the lack of selectivity, we synthesized and used sialic acid and cholesterol derivatives (SA-CH) for surface modification of the newly synthesized low-toxic colchicine derivative (BCS) nanocomposite to improve neutrophil targeting. In vivo and in vitro experiments have shown that SA-CH-modified BCS preparations are effectively absorbed by neutrophils, inhibit cell migration, reduce infiltration of tumor-associated neutrophils, enhance T lymphocyte function, and exhibit good anti-S180 early tumor effect. In addition, in a triple-negative breast cancer model, the agent could strongly inhibit tumor metastasis to the lungs.

Dual targeting single arrow: Neutrophil-targeted sialic acid-modified nanoplatform for treating comorbid tumors and rheumatoid arthritis.

Clinically, rheumatoid arthritis (RA) is frequently accompanied by multi-system diseases. Among them, the incidence of comorbid tumors in RA is relatively high, resulting in a gradual increase in mortality; this poses a considerable challenge to clinical treatment. To date, no effective treatment plan for simultaneous tumor and RA therapy is available. Accordingly, we reported a sialic acid-modified doxorubicin hydrochloride liposome (DOX-SAL) that targets peripheral blood neutrophils (PBNs), which play an important role in tumors and RA. Furthermore, the prepared liposome induced PBN apoptosis by binding to L-selectin, which is highly expressed on the surface of PBNs activated by inflammation. This liposome, in turn, reduced the accumulation of inflammatory neutrophils at the disease site. In the first successfully established mouse model of RA comorbidity, induced by employing S180 sarcoma cells and collagen, DOX-SAL effectively inhibited tumor growth while simultaneously alleviating systemic RA symptoms without side effects. Additionally, the animals demonstrated adequate growth during the 48 days of treatment. This treatment strategy encompasses the best of both worlds, breaking the deadlock that tumors and RA cannot be effectively treated in parallel, highlighting a new concept and reference for the clinical treatment of comorbid tumors and RA.

Sialic acid conjugate-modified liposomal platform modulates immunosuppressive tumor microenvironment in multiple ways for improved immune checkpoint blockade therapy.

Immune checkpoint blockade (ICB) treatment is promising for the clinical therapy of numerous malignancies. However, most cancer patients rarely benefit from such single-agent immunotherapies because of the complexity of both the tumor and tumor microenvironment. A tumor-specific liposomal vehicle (DOX-SAL) modified with a sialic acid-cholesterol conjugate (SA-CH) and remotely loaded with doxorubicin (DOX) is herein reported for improving chemoimmunotherapy. The intravenous administration of DOX-SAL dramatically downregulates tumor-associated macrophage (TAM)-mediated immunosuppression, inhibits immunoregulatory functions, and promotes intratumoral infiltration of CD8+ T cells. Compared to conventional liposomes, DOX-SAL-mediated combination therapy with a PD-1-blocking monoclonal antibody (aPD-1 mAb) almost completely eliminates B16F10 tumors and efficiently inhibits 4T1 tumors. Moreover, cancer stem cells exhibit efficient tumor-initiating, tumor-propagating, and immunosuppressive tumor microenvironment-shaping capabilities. To further improve the treatment efficacy of an immunologically "cold" tumor, metformin (MET), which selectively eradicates breast cancer tumor stem cells, is co-encapsulated with DOX into liposomes to develop DOX/MET-SAL. The combination therapy with DOX/MET-SAL and aPD-1 mAb in a 4T1 orthotopic mouse model indicates their synergetic benefit on primary tumor inhibition, metastasis suppression, and survival rate improvement. Thus, the multifunctional liposomal platform has potential value for ICB combination immunotherapy.

Targeted delivery of zoledronic acid through the sialic acid - Siglec axis for killing and reversal of M2 phenotypic tumor-associated macrophages - A promising cancer immunotherapy.

Immune checkpoint inhibitors (ICIs), like monoclonal antibodies of PD-1, CTLA-4, and their ligands, are effective only in some populations of patients with cancer, because the immunosuppressive state of the tumor microenvironment (TME) in some patients cannot be effectively reversed after ICI therapy. Sialic acid (SA) receptors in the Siglec family are highly expressed on the surface of tumor-associated macrophages (TAMs) and most have immunosuppressive effects. Therefore, targeting TAMs (the siglec axis) to reverse tumor immunosuppression may provide a new direction for the development of novel tumor immunotherapies. We designed a Zoledronic acid (ZA)-loaded liposome modified by a SA-octadecylamine conjugate (ZA-SL) to act as a novel nanomedicine delivery platform. This platform can efficiently deliver ZA to TAMs through the combination of SA and Siglec-1 and exerts specific cytotoxicity or phenotypic remodeling of M2-like TAMs depending on the drug concentration in TAMs. In vivo experiments showed that ZA-SL had good TAM targeting ability, and after treatment, the S180 tumors of mice were significantly inhibited, and the proportion of M1-like TAMs was significantly higher than that of M2-like TAMs with no significant adverse reactions in mice. Therefore, SA-modified ZA-loaded liposomes may provide a promising strategy for cancer immunotherapy.

Correlation between mouse age and human age in anti-tumor research: Significance and method establishment.

Age is closely related with the occurrence and development of tumors, and with treatment outcomes. To improve the accuracy and rigor of preclinical studies, and to enhance consistency between the preclinical research and the clinical reality, the age of experimental animals used in preclinical studies is important. The mouse genome is 99% identical to the human genome, and mice have similar patterns with respect to organs and systemic physiology. Thus, mice have been the most widely used animals in anti-tumor research. However, most mice used in such studies are 6 to 8 weeks old, ignoring the fact that different tumors may often occur in various periods, with a particular tendency to occur in later stages of life. The great difference in age limits the success rate of clinical transformation. Therefore, it is very important to choose mice of suitable age for preclinical studies and to correlate ages of human and mice. Only a few related studies have been reported and there is a lack of consistency in the findings. This review points out that age is one of the important factors in anti-tumor research, and establishes a new method for calculating the age correlation between humans and mice. The equations obtained from the method can help researchers conveniently determine suitable aged mouse for their research, which will improve the rigor of their experimental results. Furthermore, this method can be used beyond anti-tumor research, in studies on other diseases that use mouse as an animal model.