One step closer to cancer nanomedicine

A multicomponent nanosystem for capturing circulating tumor cells from cancer patients with PD-L1 as an immunotherapy oncotarget

Capturing circulating tumor cells (CTCs) from the peripheral blood of cancer patients, where they are disseminated among billions of other blood cells, is one of the most daunting challenge. We report OncoDiscover®, a multicomponent nano-system consisting of iron oxide (Fe3O4) nanoparticles (NPs), polyamidoamine generation 4 dendrimers (PAMAM-G4-NH2), graphene oxide (GO) sheets and an anti-epithelial cell adhesion molecule (anti-EpCAM) antibody (Fe-GSH-PAMAM-GO-EpCAM) for the selective and precise capture of CTCs. We further evaluated this system for therapeutically important oncotargets, exemplifying overexpression of the programmed death ligand 1 (PD-L1) as a functional assay on CTCs in cancer patients. We retrospectively evaluated 134 cancer patients for the presence of CTCs and 113 (84%) showed the presence of CTCs. About 62 (55%) of the CTC +ve patients showed CTCs with PD-L1 expression. The personalized cancer detection demonstrated by the OncoDiscover® CTC analysis tool is highly relevant for cancer monitoring and treatment outcomes.

Modulating Elasticity of Liposome for Enhanced Cancer Immunotherapy

Cancer immunotherapy has emerged as a promising approach to cancer treatment in recent years. The physical and chemical properties of nanocarriers are critical factors that regulate the immune activation of antigen-presenting cells (APCs) in the tumor microenvironment (TME). Herein, we extensively investigated the behavior of liposome nanoparticles (Lipo-NPs) with different elasticities, focusing on their interaction with immune cells and their transport mechanisms from tumors to tumor-draining lymph nodes (tdLNs). Successfully preparing Lipo-NPs with distinct elastic properties, their varied behaviors were observed, concerning immune cell interaction. Soft Lipo-NPs exhibited an affinity to cell membranes, while those with medium elasticity facilitated the cargo delivery to macrophages through membrane fusion. Conversely, hard Lipo-NPs enter macrophages via classical cellular uptake pathways. Additionally, it was noted that softer Lipo-NPs displayed superior transport to tdLNs in vivo, attributed to their deformable nature with lower elasticity. As a result, the medium elastic Lipo-NPs with agonists (cGAMP), by activating the STING pathway and enhancing transport to tdLNs, promoted abundant infiltration of tumor-infiltrating lymphocytes (TILs), leading to notable antitumor effects and extended survival in a melanoma mouse model. Furthermore, this study highlighted the potential synergistic effect of medium elasticity Lipo-NPs with immune checkpoint blockade (ICB) therapy in preventing tumor immune evasion. These findings hold promise for guiding immune-targeted delivery systems in cancer immunotherapy, particularly in vaccine design for tdLNs targeting and eradicating metastasis within tdLNs.

Tumor Microenvironment ROS/pH Cascade-Responsive Supramolecular Nanoplatform with ROS Regeneration Property for Enhanced Hepatocellular Carcinoma Therapy

The low targeted drug delivery efficiency, including poor tumor accumulation and penetration and uncontrolled drug release, leads to the failure of cancer therapy. Herein, a multifunctional supramolecular nanoplatform loading triptolide (TPL/PBAETK@GA NPs) was fabricated via the host-guest interaction between glycyrrhetinic-acid-modified poly(ethylene glycol)-adamantanecarboxylic acid moiety and reactive oxygen species (ROS)/pH cascade-responsive copolymer poly(β-amino esters)-thioketal (TK)-β-cyclodextrin. TPL/PBAETK@GA NPs could accumulate in hepatocellular carcinoma (HCC) tissue effectively, mediated by nanoscale advantage and GA' recognition to specific receptors. The elevated concentration of ROS in tumor microenvironment (TME) quickly breaks the TK linkages, causing the detachment of shell (cyclodextrin) CD layer. Then, the accompanying negative-to-positive charge-reversal of NPs was realized via the PBAE moiety protonation under the slightly acidic TME, significantly enhancing the NPs' cellular internalization. Remarkably, the pH-responsive endo/lysosome escape of PBAE core triggered intracellular TPL burst release, promoting the cancer cell apoptosis, autophagy, and intracellular ROS generation, leading to the self-amplification of ROS in TME. Afterward, the ROS positive-feedback loop was generated to further promote size-shrinkage and charge-reversal of NPs. Both in vitro and in vivo tests verified that TPL/PBAETK@GA NPs produced a satisfactory anti-HCC therapy outcome. Collectively, this study offers a potential appealing paradigm to enhance TPL-based HCC therapy outcomes via multifunctionalized supramolecular nanodrugs.

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Critical point for membrane bilayer formation

Unilamellar liposomes often are employed in investigations of lipid-protein interactions and the delivery of drugs in therapies for disease. Also, related lipid-containing nanoparticles have been developed as elements of a new class of mRNA vaccines. We show that only unilamellar films form in equilibrium lipid dispersions, at temperature values {T*} that depend on the identities of the lipids (e.g., T* ≈ 29 °C for DMPC). Thermodynamic analysis confirms that films at air-water surfaces can be used to monitor the properties of the lipid vesicles that form in the dispersion. When T > T*, critical exponents describing film properties as T approaches T* are μ ≈ 1.4 and ν ≈ 0.7, which are close to values for the interfacial tension and the correlation length of density fluctuations at fluid interfaces. These results, and observations that within the bilayer the lateral diffusion of fluorescent lipid probes demonstrates increases at T*, suggest that unilamellar vesicles at T* are a transition state between two different multilamellar structures. We generalize the thermodynamic arguments to explain the linkage between lipid structures in the surface and bulk dispersion within more complex samples, showing that dispersions containing total lipid extracts of cell membranes have properties similar to those in dispersions containing single lipids. Information from various independent studies indicates that T* noted for bilayer membranes of a population of cells is identical to the temperature at which the growth or gestation of the cells occurs in vivo. Examples include whole-cell lipid extracts obtained from bacteria, and poikilothermic and homeothermic animals.

Improving crossing of multiple bio-delivery barriers by a novel bio-interface design based on hydrophobic nanoparticle surfaces

Biological delivery remains a major challenge in biotechnology, partly because it is often not enough to overcome a single delivery barrier. It is highly desirable, yet rarely available, to design delivery carriers with both simple structures and the ability to cross multiple delivery barriers with high efficiency. Herein, we describe a distinct design (dubbed 'SDot') of delivery carriers with a single structural feature that can enhance the crossing of multiple delivery barriers. The bio-interface (the interface with a biological environment) of an SDot nanoparticle is highly hydrophobic, thus enhancing its interactions with lipid membranes, which are the primary components of many bio-delivery barriers. We used quantum dots (QDs) as the model core material of SDots and conjugated them with a RGD peptide. Thus-formed SDots-RGD demonstrated greatly improved abilities of cellular uptake and transcytosis in a brain tumor cell line, U87MG, compared with the conventional nanoparticle counterpart with a hydrophilic bio-interface (wQDs-RGD). Further, after loading a microtubule-binding anticancer drug, paclitaxel (PTX), onto the nanoparticle surface of SDots-RGD, the resulting drug formulation PTX@SDots-RGD displayed excellent ability of intracellular targeting to microtubules in U87MG cells. In a small animal cancer model, PTX@SDots-RGD exhibited significantly higher ability to slow down brain tumor growth than that of PTX@wQDs-RGD and free PTX. Taken together, these experimental results indicated the significant potential of SDots-RGD for bio-delivery, although the possible long-term toxicity of QDs used as the core material needs to be addressed in future work by replacing QDs with clinically approved materials.

Covalent Organic Framework Nanobowls as Activatable Nanosensitizers for Tumor-Specific and Ferroptosis-Augmented Sonodynamic Therapy

Covalent organic frameworks (COFs) have attracted increasing attention for biomedical applications. COFs-based nanosensitizers with uniform nanoscale morphology and tumor-specific curative effects are in high demand; however, their synthesis is yet challenging. In this study, distinct COF nanobowls are synthesized in a controlled manner and engineered as activatable nanosensitizers with tumor-specific sonodynamic activity. High crystallinity ensures an ordered porous structure of COF nanobowls for the efficient loading of the small-molecule sonosensitizer rose bengal (RB). To circumvent non-specific damage to normal tissues, the sonosensitization effect is specifically inhibited by the in situ growth of manganese oxide (MnOx ) on RB-loaded COFs. Upon reaction with tumor-overexpressed glutathione (GSH), the "gatekeeper" MnOx is rapidly decomposed to recover the reactive oxygen species (ROS) generation capability of the COF nanosensitizers under ultrasound irradiation. Increased intracellular ROS stress and GSH consumption concomitantly induce ferroptosis to improve sonodynamic efficacy. Additionally, the unconventional bowl-shaped morphology renders the nanosensitizers with enhanced tumor accumulation and retention. The combination of tumor-specific sonodynamic therapy and ferroptosis achieves high efficacy in killing cancer cells and inhibiting tumor growth. This study paves the way for the development of COF nanosensitizers with unconventional morphologies for biomedicine, offering a paradigm to realize activatable and ferroptosis-augmented sonodynamic tumor therapy.

Fluorination Effects on the Drug Delivery Property of Cylindrical Polymer Brushes

Fluorination has been widely applied to improving the properties of small-molecule drugs. However, relatively little is known about the effects of fluorination on the drug delivery property of nanomaterials. In this paper, we synthesized a fluoroalkane-modified cylindrical polymer brush (CPB) BCPB-F and an alkane-modified analogue BCPB-H. Doxorubicin (DOX) was used as a model drug and was loaded onto the CPBs through a pH-responsive acylhydrazone linkage. High drug loading and good water solubility were achieved. The in vitro and in vivo experiments suggested that fluorination played an important role in improving the cellular uptake, blood circulation, tissue permeability, and tumor targeting ability of CPBs. Due to these superiorities, the DOX-loaded BCPB-F exhibited excellent antitumor efficacy and eradicated the tumors of mice after five-dose treatments. The well-defined structures of the drug-free and drug-loaded CPBs guaranteed the accuracy of the results. This work demonstrates that fluorination is a promising strategy to improve the overall properties of nanomedicines.