The clinical prospects of cancer nanomedicines depend on effective patient stratification. Here we report the identification of predictive biomarkers of the accumulation of nanomedicines in tumour tissue. By using supervised machine learning on data of the accumulation of nanomedicines in tumour models in mice, we identified the densities of blood vessels and of tumour-associated macrophages as key predictive features. On the basis of these two features, we derived a biomarker score correlating with the concentration of liposomal doxorubicin in tumours and validated it in three syngeneic tumour models in immunocompetent mice and in four cell-line-derived and six patient-derived tumour xenografts in mice. The score effectively discriminated tumours according to the accumulation of nanomedicines (high versus low), with an area under the receiver operating characteristic curve of 0.91. Histopathological assessment of 30 tumour specimens from patients and of 28 corresponding primary tumour biopsies confirmed the score’s effectiveness in predicting the tumour accumulation of liposomal doxorubicin. Biomarkers of the tumour accumulation of nanomedicines may aid the stratification of patients in clinical trials of cancer nanomedicines.

Hepatocellular carcinoma (HCC) constitutes a devastating health burden. Recently, tumor microenvironment-directed interventions have profoundly changed the landscape of HCC therapy. In the present study, the function of the chemokine CXCL10 during fibrosis-associated hepatocarcinogenesis was analyzed with specific focus on its impact in shaping the tumor microenvironment. C57BL/6J wild type (WT) and Cxcl10 knockout mice (Cxcl10^−/−) were treated with diethylnitrosamine (DEN) and tetrachloromethane (CCl₄) to induce fibrosis-associated HCCs. Cxcl10 deficiency attenuated hepatocarcinogenesis by decreasing tumor cell proliferation as well as tumor vascularization and modulated tumor-associated extracellular matrix composition. Furthermore, the genetic inactivation of Cxcl10 mediated an alteration of the tumor-associated immune response and modified chemokine/chemokine receptor networks. The DEN/CCl₄-treated Cxcl10^−/− mice presented with a pro-inflammatory tumor microenvironment and an accumulation of anti-tumoral immune cells in the tissue. The most striking alteration in the Cxcl10^−/− tumor immune microenvironment was a vast accumulation of anti-tumoral T cells in the invasive tumor margin. In summary, our results demonstrate that CXCL10 exerts a non-redundant impact on several hallmarks of the tumor microenvironment and especially modulates the infiltration of anti-tumorigenic immune cells in HCC. In the era of microenvironment-targeted HCC therapies, interfering with CXCL10 defines a novel asset for further improvement of therapeutic strategies.

Immature and hyperpermeable vessels and active transport through endothelial cells, combined with impaired lymphatic clearance and uptake by tumor-associated macrophages, contribute to the accumulation of anticancer drugs in tumors. These so-called "Enhanced Permeability and Retention" (EPR) and "Active Transport and Retention" (ATR) effects are pronounced for nanomedicines. However, while little is known about ATR, EPR is heterogeneous within tumors and patients, limiting the therapeutic efficacy of EPR-based drug delivery systems (DDS). This review discusses strategies to refine and complement EPR-based drug delivery. One possibility is to better stratify patients for therapy using histological and omics biomarkers as well as via companion diagnostics and theranostics. Active targeting of DDS could be used to improve retention and internalization by tumor cells. In addition, active targeting of endothelial cells is increasingly being discussed to promote drug accumulation in tumors by transcytosis. Other strategies include pharmacological or (image-guided) physical priming of the tumor microenvironment. Pharmacological priming has been successfully demonstrated with angiogenic factors to increase vascular maturity, erythropoietin to increase perfusion, and corticosteroids to remodel vessels and the associated extracellular matrix (ECM). Physical priming has been carried out using heat, radiation and ultrasound. The latter is often used in combination with microbubbles that oscillate or burst upon stimulation, mechanically untightening the vessel walls and adjacent ECM. Clinically, this strategy is being evaluated in particular for brain tumors. Thus, EPR-dependent drugs may greatly benefit from patient pre-selection strategies and complementary interventions targeting biological barriers between the injection site and the target.

Modifying biological agents with polymers such as polyethylene glycol (PEG) has demonstrated clinical benefits; however, post-market surveillance of PEGylated derivatives has revealed PEG-associated toxicity issues, prompting the search for alternatives. We explore how conjugating a poly-l-glutamic acid (PGA) to an anti-insulin growth factor 1 receptor antibody (AVE1642) modulates the bio-nano interface and anti-tumor activity in preclinical prostate cancer models. Native and PGA-modified AVE1642 display similar anti-tumor activity in vitro; however, AVE1642 prompts IGF-1R internalization while PGA conjugation prompts higher affinity IGF-1R binding, thereby inhibiting IGF-1R internalization and altering cell trafficking. AVE1642 attenuates phosphoinositide 3-kinase signaling, while PGA-AVE1642 inhibits phosphoinositide 3-kinase and mitogen-activated protein kinase signaling. PGA conjugation also enhances AVE1642's anti-tumor activity in an orthotopic prostate cancer mouse model, while PGA-AVE1642 induces more significant suppression of cancer cell proliferation/angiogenesis than AVE1642. These findings demonstrate that PGA conjugation modulates an antibody's bio-nano interface, mechanism of action, and therapeutic activity.

Drug delivery to central nervous pathologies is compromised by the blood-brain barrier (BBB). A clinically explored strategy to promote drug delivery across the BBB is sonopermeation, which relies on the combined use of ultrasound (US) and microbubbles (MB) to induce temporally and spatially controlled opening of the BBB. We developed an advanced in vitro BBB model to study the impact of sonopermeation on the delivery of the prototypic polymeric drug carrier pHPMA as a larger molecule and the small molecule antiviral drug ribavirin. This was done under standard and under inflammatory conditions, employing both untargeted and RGD peptide-coated MB. The BBB model is based on human cerebral capillary endothelial cells and human placental pericytes, which are co-cultivated in transwell inserts and which present with proper transendothelial electrical resistance (TEER). Sonopermeation induced a significant decrease in TEER values and facilitated the trans-BBB delivery of fluorescently labeled pHPMA (Atto488-pHPMA). To study drug delivery under inflamed endothelial conditions, which are typical for e.g. tumors, neurodegenerative diseases and CNS infections, tumor necrosis factor (TNF) was employed to induce inflammation in the BBB model. RGD-coated MB bound to and permeabilized the inflamed endothelium-pericyte co-culture model, and potently improved Atto488-pHPMA and ribavirin delivery. Taken together, our work combines in vitro BBB bioengineering with MB-mediated drug delivery enhancement, thereby providing a framework for future studies on optimization of US-mediated drug delivery to the brain. Graphical abstract

Reproducibility is a significant concern in scientific research and complex methods like quantitative polymerase chain reaction (qPCR) demand stringent reporting standards to ensure that the methods are reproducible, data are sound, and conclusions are trustworthy. Although the MIQE (Minimum Information for Publication of Quantitative Real-Time PCR Experiments) guidelines were introduced in 2009 to improve qPCR reporting, a 2013 study identified ongoing deficiencies that hinder reproducibility. To further investigate the transparency and completeness of qPCR reporting, we systematically assessed articles published in the top 20 journals in genetics and heredity (n=186) and plant sciences (n=246) that used qPCR. Our analysis revealed frequent omissions and inadequate specification of critical information necessary for evaluating and replicating qPCR experiments. RNA integrity, along with assessment methods and instruments used to assess it, are seldom reported. Although primer sequences are often disclosed, names and accession numbers of housekeeping genes are frequently omitted. Additionally, essential details about RNA extraction, RNA-to-cDNA conversion, and qPCR, such as kit names, catalog numbers, and reagent information, are often missing. Our findings underscore the urgent need for improved reporting practices in qPCR experiments, emphasizing quality controls, detailed descriptions of reagents and materials, and greater analytical transparency. Addressing these reporting deficiencies is crucial for enhancing the reproducibility and evaluating the trustworthiness of qPCR research. Potential solutions include encouraging authors to cite protocols published in online repositories, providing reporting templates, or developing automated tools to check reporting compliance.