Cell-based Relay Delivery Strategy in Biomedical Applications

Neutrophil-Camouflaged Stealth Liposomes for Photothermal-Induced Tumor Immunotherapy Through Intratumoral Bacterial Activation

Objective: F. nucleatum, a tumor-resident bacterium colonizing breast cancer (BC), results in an immunosuppressive microenvironment and facilitates tumor growth and metastasis. This study aimed to develop a neutrophil-based liposome delivery system designed for dual-targeted elimination of tumor cells and F. nucleatum, while simultaneously upregulating pathogen-associated molecular patterns and damage-associated molecular patterns to potentiate tumor immunotherapy. Methods: The liposomes (PD/GA-LPs) loaded with the perylene diimide complex (PD) and gambogic acid (GA) were fabricated via the extrusion method. Subsequently, comprehensive evaluations including physicochemical characteristics, antibacterial activity, antitumor effect, and immunomodulatory effect evaluation were systematically conducted to validate the feasibility of this delivery system. Results: The resulting PD/GA-LPs exhibited a dynamic size (121.3 nm, zeta potential -44.1 mV) and a high encapsulation efficiency of approximately 78.1% (PD) and 91.8% (GA). In addition, the optimized PD/GA-LPs exhibited excellent photothermal performance and antibacterial efficacy. In vitro cellular experiments revealed that PD/GA-LPs exhibited enhanced internalization by neutrophils, followed by extracellular trap-mediated release, ultimately significantly inhibiting tumor cell proliferation and inducing immunogenic cell death. During in vivo treatment, PD/GA-LPs exhibited targeted tumor accumulation, where F. nucleatum-driven PD reduction activated near-infrared-responsive photothermal ablation. When combined with GA, this delivery system effectively eliminated tumor cells and F. nucleatum, while facilitating the subsequent T-cell infiltration. Conclusions: This strategy amplified the antitumor immune response, thus leading to effective treatment of BC and prevention of metastasis. In summary, this approach, grounded in the distinct microecology of tumor and normal tissues, offers novel insights into the development of precise and potent immunotherapies for BC.

Reprogramming monocytes into M2 macrophages as living drug depots to enhance treatment of myocardial ischemia-reperfusion injury

Delivering therapeutic agents efficiently to inflamed regions remains an intractable challenge following myocardial ischemia-reperfusion injury (MI/RI) due to the transient nature of the enhanced permeability and retention effect, which disappears after 24 h. Leveraging the inflammation-homing and plasticity properties of circulating monocytes (MN) as hitchhiking carriers and further inducing their polarization into anti-inflammatory phenotype macrophages upon reaching the inflamed sites is beneficial for MI/RI therapy. Herein, DSS/PB@BSP nanoparticles capable of clearing reactive oxygen species and inhibiting inflammation were developed by employing hollow Prussian blue nanoparticles (PB) as carriers to encapsulate betamethasone sodium phosphate (BSP) and further modified with dextran sulfate sodium (DSS), a targeting ligand for the scavenger receptor on MN. This formulation was internalized into MN as living cell drug depots, reprogramming them into anti-inflammation type macrophages to inhibit inflammation. In vitro assessments revealed the successful construction of the nanoparticle. In a murine MI/RI model, circulating MN laden with these nanoparticles significantly enhanced drug delivery and accumulation at the cardiac injury site, exhibiting favorable therapeutic ability and promoting M2-biased differentiation. Our study provides an effective approach with minimally invasion and biosecurity that makes this nanoplatform as a promising candidate for immunotherapy and clinical translation in the treatment of MI/RI.

AI-powered omics-based drug pair discovery for pyroptosis therapy targeting triple-negative breast cancer

Due to low success rates and long cycles of traditional drug development, the clinical tendency is to apply omics techniques to reveal patient-level disease characteristics and individualized responses to treatment. However, the heterogeneous form of data and uneven distribution of targets make drug discovery and precision medicine a non-trivial task. This study takes pyroptosis therapy for triple-negative breast cancer (TNBC) as a paradigm and uses data mining of a large TNBC cohort and drug databases to establish a biofactor-regulated neural network for rapidly screening and optimizing compound pyroptosis drug pairs. Subsequently, biomimetic nanococrystals are prepared using the preferred combination of mitoxantrone and gambogic acid for rational drug delivery. The unique mechanism of obtained nanococrystals regulating pyroptosis genes through ribosomal stress and triggering pyroptosis cascade immune effects are revealed in TNBC models. In this work, a target omics-based intelligent compound drug discovery framework explores an innovative drug development paradigm, which repurposes existing drugs and enables precise treatment of refractory diseases.

Dendritic Nanomedicine with Boronate Bonds for Augmented Chemo-Immunotherapy via Synergistic Modulation of Tumor Immune Microenvironment

Unsatisfied tumor accumulation of chemotherapeutic drugs and a complicated immunosuppressive microenvironment diminish the immune response rate and the therapeutic effect. Surface modification of these drugs with target ligands can promote their cellular internalization, but the modified drugs may be subjected to unexpected immune recognition and clearance. Herein, a phenylboronic acid (PBA) group-shieldable dendritic nanomedicine that integrates an immunogenic cell death (ICD)-inducing agent (epirubicin, Epi) and an indoleamine 2,3-dioxgenase 1 (IDO1) inhibitor (NLG919) is reported for tumor chemo-immunotherapy. This NLG919-loaded Epi-conjugated PEGylated dendrimers bridged with boronate bonds (NLG919@Epi-DBP) maintains a stable nanostructure during circulation. Under a moderate acidic condition, the PBA group exposes to the sialic acid residue on the tumor cell membrane to enhance the internalization and penetration of NLG919@Epi-DBP. At pH 5.0, NLG919@Epi-DBP rapidly disassembles to release the incorporated Epi and NLG919. Epi triggers robust ICD of tumor cells that evokes strong immune response. In addition, inhibition of the IDO1 activity downregulates the metabolism of L-tryptophan to kynurenine, leading to a reduction in the recruitment of immunosuppressive cells and modulation of the tumor immune microenvironment. Collectively, this promising strategy has been demonstrated to evoke robust immune response as well as remodel the immunosuppressive microenvironment for an enhanced chemo-immunotherapeutic effect.

In situ cellular hitchhiking of nanoparticles for drug delivery

Since the inception of the concept of "magic bullet", nanoparticles have evolved to be one of the most effective carriers in drug delivery. Nanoparticles improve the therapeutic efficacy of drugs offering benefits to treating various diseases. Unlike free drugs which freely diffuse and distribute through the body, nanoparticles protect the body from the drug by reducing non-specific interactions while also improving the drug's pharmacokinetics. Despite acquiring some FDA approvals, further clinical application of nanoparticles is majorly hindered by its limited ability to overcome biological barriers resulting in uncontrolled biodistribution and high clearance. The use of cell-inspired systems has emerged as a promising approach to overcome this challenge as cells are biocompatible and have improved access to tissues and organs. One of such is the hitchhiking of nanoparticles to circulating cells such that they are recognized as 'self' components evading clearance and resulting in site-specific drug delivery. In this review, we discuss the concept of nanoparticle cellular hitchhiking, highlighting its advantages, the principles governing the process and the challenges currently limiting its clinical translation. We also discuss in situ hitchhiking as a tool for overcoming these challenges and the considerations to be taken to guide research efforts in advancing this promising technology.