Compared with traditional chemotherapeutics, vascular disruption agents (VDAs) have the advantages of rapidly blocking the supply of nutrients and starving tumors to death. Although the VDAs are effective under certain scenarios, this treatment triggers angiogenesis in the later stage of therapy that frequently leads to tumor recurrence and treatment failure. Additionally, the nonspecific tumor targeting and considerable side effects also impede the clinical applications of VDAs. Here we develop a customized strategy that combines a VDA with an anti-angiogenic drug (AAD) using mesoporous silica nanoparticles (MSNs) coated with platelet membrane for the self-assembled tumor targeting accumulation. The tailor-made nanoparticles accumulate in tumor tissues through the targeted adhesion of platelet membrane surface to damaged vessel sites, resulting in significant vascular disruption and efficient anti-angiogenesis in animal models. This study demonstrates the promising potential of combining VDA and AAD in a single nanoplatform for tumor eradication.

Nanoparticle (NP) delivery to solid tumors remains an actively studied field, where several recent studies have shed new insights into the underlying mechanisms and the still overall poor efficacy. In the present study, Au NPs of different sizes were used as model systems to address this topic, where delivery of the systemically administered NPs to the tumor as a whole or to tumor cells specifically was examined in view of a broad range of tumor-associated parameters. Using non-invasive imaging combined with histology, immunohistochemistry, single-cell spatial RNA expression and image-based single cell cytometry revealed a size-dependent complex interaction of multiple parameters that promoted tumor and tumor-cell specific NP delivery. Interestingly, the data show that most NPs are sequestered by tumor-associated macrophages and cancer-associated fibroblasts, while only few NPs reach the actual tumor cells. While perfusion is important, leaky blood vessels were found not to promote NP delivery, but rather that delivery efficacy correlated with the maturity level of tumor-associated blood vessels. In line with recent studies, we found that the presence of specialized endothelial cells, expressing high levels of CD276 and Plvap promoted both tumor delivery and tumor cell-specific delivery of NPs. This study identifies several parameters that can be used to determine the suitability of NP delivery to the tumor region or to tumor cells specifically, and enables personalized approaches for maximal delivery of nanoformulations to the targeted tumor. Graphical Abstract

Overproduction of reactive oxygen species (ROS), a key characteristic of inflammatory bowel disease (IBD), is responsible for dysregulation of signal transduction, inflammatory response, and DNA damage, which ultimately leads to disease progression and deterioration. Thus, ROS scavenging has become a promising strategy to navigate IBD. Inspired by the targeting capability of hyaluronic acid (HA) to CD44-overexpressed inflammatory cells together with the redox regulation capacity of diselenide compounds, we developed an oral nanoformulation, i.e., diselenide-bridged hyaluronic acid nanogel (SeNG), with a view to treat colitis through a ROS scavenging mechanism. Our data demonstrated that SeNG specifically accumulated in colitis tissue that was mediated by highly efficient CD44–HA interaction. This has allowed us to demonstrate a significant anti-inflammatory effect in an acute colitis mouse model induced by dextran sulfate sodium and trinitrobenzenesulfonic acid. Mechanistically, we continued to show SeNG reduced the ROS level via both direct elimination and up-regulation of the Nrf2/HO-1 signal pathway. Collectively, our work provides proof-of-principle evidence for a SeNG-mediated nano-antioxidant strategy, by which colitis could be effectively managed.

New strategies to decrease risk of relapse after surgery are needed for improving 5‐year survival rate of hepatocellular carcinoma (HCC). To address this need, a wound‐targeted nanodrug is developed, that contains an immune checkpoint inhibitor (anti‐PD‐L1)and an angiogenesis inhibitor (sorafenib)). These nanoparticles consist of highly biocompatible mesoporous silica (MSNP) that is surface‐coated with platelet membrane (PM) to achieve surgical site targeting in a self‐amplified accumulation manner. Sorafenib is introduced into the MSNP pores while covalently attaching anti‐PD‐L1 antibody on the PM surface. The resulting nano‐formulation, abbreviated as a‐PM‐S‐MSNP, can effectively target the surgical margin when intraperitoneally (IP) administered into an immune competent murine orthotopic HCC model. Multiple administrations of a‐PM‐S‐MSNP generate potent anti‐HCC effect and significantly prolong overall mice survival. Immunophenotyping and immunochemistry staining reveal the signatures of favorable anti‐HCC immunity and anti‐angiogenesis effect at tumor sites. More importantly, microscopic inspection of a‐PM‐S‐MSNP treated mice shows that 2 out 6 are histologically tumor‐free, which is in sharp contrast to the control mice where tumor foci can be easily identified. The data suggest that a‐PM‐S‐MSNP can efficiently inhibit post‐surgical HCC relapse without obvious side effects and holds considerable promise for clinical translation as a novel nanodrug.

Nanoparticle delivery to solid tumors is known to be an inefficient process and various studies have tried to increase efficacy, but mechanistic and comparative studies remain scarce. Here, we use pharmacological agents to study the effect of vessel normalization or vessel disintegration on nanoparticle delivery to solid tumors. Using a multiparametric approach, we find that vessel disintegration fails to improve nanoparticle delivery and instead seems to have a limiting effect. Vessel normalization, however, improves delivery efficacy for nanoparticles ranging from 20 to 60 nm diameter. The normalization of the tumor blood vessels results in reduced hypoxia, reduced necrosis and an increase in Plvap+ CD276+ endothelial cells, which have been linked with nanoparticle delivery. Interestingly, where vessel disintegration stimulated cancer cell intravasation and associated metastases, vessel normalization impeded these processes. Together, these data reveal that, vessel normalization may be a safer and more suited approach for improving nanoparticle delivery to solid tumors, but its efficacy is limited by nanoparticle diameter and tumor parameters.

Nanoparticles (NPs) spanning diverse materials and properties have the potential to encapsulate and protect a wide range of therapeutic cargos to increase bioavailability, prevent undesired degradation, and mitigate toxicity. Fulvestrant, a selective estrogen receptor degrader (SERD), is commonly used for treating estrogen receptor (ER)-positive breast cancer patients, but its broad and continual application is limited by poor solubility, invasive muscle administration, and drug resistance. Here, we developed an active targeting motif-modified, intravenously injectable, hydrophilic NP that encapsulates fulvestrant to facilitate its delivery via the bloodstream to tumors, improving bioavailability and systemic tolerability. Additionally, the NP was co-loaded with abemaciclib, an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), to prevent the development of drug resistance associated with long-term fulvestrant treatment. Targeting peptide modifications on the NP surface assisted in the site-specific release of the drugs to ensure specific toxicity in the tumor tissues and spare normal tissue. The NP formulation (PPFA-cRGD) exhibited efficient tumor cell killing in both in vitro organoid models and in vivo orthotopic ER-positive breast cancer models without apparent adverse effects, as verified in mouse and Bama miniature pig models. This NP-based therapeutic provides an opportunity for continual and extensive clinical application of fulvestrant, thus indicating its promise as a treatment option for patients with ER-positive breast cancer.

Inspired by the structure of eukaryotic cells, multicompartmental microcapsules have gained increasing attention. However, challenges remain in the fabrication of "all-aqueous" (i.e., oil-free) microcapsules composed of accurately adjustable hierarchical compartments. This study reports on multicompartmental microcapsules with an innovative architecture. While multicompartmental cores of the microcapsules were fabricated through gas shearing, a shell was applied on the cores through surface gelation of alginate. Different from traditional multicompartmental microcapsules, thus obtained microcapsules have well-segregated compartments while the universal nature of the surface-gelation method allows us to finely tune the shell thicknesses of the microcapsules. The microcapsules are highly stable and cytocompatible and allow repeated enzymatic cascade reactions, which might make them of interest for complex biocatalysis or for mimicking physiological processes.

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