Photo-induced crosslinked and anti-PD-L1 peptide incorporated liposomes to promote PD-L1 multivalent binding for effective immune checkpoint blockade therapy.

Immune checkpoint blockade (ICB) therapy targeting PD-L1 monoclonal antibody (mAb) has shown extensive clinical benefits in the diverse types of advanced malignancies. However, most patients are completely refractory to ICB therapy owing to the PD-L1 recycling mechanism. Herein, we propose photo-induced crosslinked and anti-PD-L1 peptide incorporated liposomes (immune checkpoint blockade liposomes; ICB-LPs) to promote PD-L1 multivalent binding for inducing lysosomal degradation of PD-L1 in tumor cells.

All-in-one glycol chitosan nanoparticles for co-delivery of doxorubicin and anti-PD-L1 peptide in cancer immunotherapy.

Synergistic immunotherapy of immune checkpoint blockade (ICB) and immunogenic cell death (ICD) has shown remarkable therapeutic efficacy in various cancers. However, patients show low response rates and undesirable outcomes to these combination therapies owing to the recycling mechanism of programmed death-ligand 1 (PD-L1) and the systemic toxicity of ICD-inducing chemotherapeutic drugs. Herein, we propose all-in-one glycol chitosan nanoparticles (CNPs) that can deliver anti-PD-L1 peptide (PP) and doxorubicin (DOX) to targeted tumor tissues for a safe and more effective synergistic immunotherapy.

Implantable micro-scale LED device guided photodynamic therapy to potentiate antitumor immunity with mild visible light.

Background: Photodynamic therapy (PDT) is a promising strategy to promote antitumor immunity by inducing immunogenic cell death (ICD) in tumor cells. However, practical PDT uses an intense visible light owing to the shallow penetration depth of the light, resulting in immunosuppression at the tumor tissues.

Methods: Herein, we propose an implantable micro-scale light-emitting diode device (micro-LED) guided PDT that enables the on-demand light activation of photosensitizers deep in the body to potentiate antitumor immunity with mild visible light.

Mesenchymal Stem Cell-Mediated Deep Tumor Delivery of Gold Nanorod for Photothermal Therapy.

Gold nanoparticles (AuNPs) with various sizes and morphologies have been extensively investigated for effective photothermal therapy (PTT) against multiple cancer types. However, a highly dynamic and complex tumor microenvironment (TME) considerably reduces the efficacy of PTT by limiting deep tumor penetration of AuNPs. Herein, we propose a mesenchymal stem cell (MSC)-mediated deep tumor delivery of gold nanorod (AuNR) for a potent PTT.

Liposome-mediated PD-L1 multivalent binding promotes the lysosomal degradation of PD-L1 for T cell-mediated antitumor immunity.

Immune checkpoint blockade (ICB) has shown remarkable therapeutic efficacy in a variety of cancers. However, patients exhibit unexpectedly low response rates to ICB therapy owing to the unwanted recycling and cellular abundance of PD-L1. Herein, rational design of PD-L1 multivalent binding liposome is investigated through PEGylated liposomes incorporating different ratios of PD-L1 binding peptide.

Preclinical development of carrier-free prodrug nanoparticles for enhanced antitumor therapeutic potential with less toxicity.

Background: Nanomedicine has emerged as a promising strategy for cancer treatment. The most representative nanomedicine used in clinic is PEGylated liposomal doxorubicin DOXIL, which is first FDA-approved nanomedicine. However, several shortcomings, such as low drug loading capacity, low tumor targeting, difficulty in mass production and potential toxicity of carrier materials, have hindered the successful clinical translation of nanomedicines.

Comparative study of cathepsin B-cleavable linkers for the optimal design of cathepsin B-specific doxorubicin prodrug nanoparticles for targeted cancer therapy.

A carrier-free prodrug nanoparticle has emerged as a potential approach to cancer therapy. It plays a vital role in enhancing the tumor targeting and therapeutic efficacy of the anticancer agent at sites of intention wherein the prodrug nanoparticle is potentially activated. Herein, five derivatives of cathepsin B-cleavable prodrugs are synthesized via chemically conjugating different cathepsin B-cleavable peptides (Phe-Arg-Arg-Gly, Phe-Arg-Arg-Leu, Phe-Arg-Arg-Leu-Gly, Phe-Leu-Arg-Arg-Gly) to doxorubicin (DOX).

Anti-PD-L1 peptide-conjugated prodrug nanoparticles for targeted cancer immunotherapy combining PD-L1 blockade with immunogenic cell death.

Cancer immunotherapy combining immune checkpoint blockade (ICB) with chemotherapeutic drugs has provided significant clinical advances. However, such combination therapeutic regimen has suffered from severe toxicity of both drugs and low response rate of patients. In this study, we propose anti-PD-L1 peptide-conjugated prodrug nanoparticles (PD-NPs) to overcome these obstacles of current cancer immunotherapy.

Tumor-activated carrier-free prodrug nanoparticles for targeted cancer Immunotherapy: Preclinical evidence for safe and effective drug delivery.

As immunogenic cell death (ICD) inducers initiating antitumor immune responses, certain chemotherapeutic drugs have shown considerable potential to reverse the immunosuppressive tumor microenvironment (ITM) into immune-responsive tumors. The application of these drugs in nanomedicine provides a more enhanced therapeutic index by improving unfavorable pharmacokinetic (PK) profiles and inefficient tumor targeting. However, the clinical translation of conventional nanoparticles is restricted by fundamental problems, such as risks of immunogenicity and potential toxicity by carrier materials, premature drug leakage in off-target sites during circulation, low drug loading contents, and complex structure and synthetic processes that hinder quality control (QC) and scale-up industrial production.

Cathepsin B-Overexpressed Tumor Cell Activatable Albumin-Binding Doxorubicin Prodrug for Cancer-Targeted Therapy.

Prodrugs are bioreversible medications that should undergo an enzymatic or chemical transformation in the tumor microenvironment to release active drugs, which improve cancer selectivity to reduce toxicities of anticancer drugs. However, such approaches have been challenged by poor therapeutic efficacy attributed to a short half-life and low tumor targeting. Herein, we propose cathepsin B-overexpressed tumor cell activatable albumin-binding doxorubicin prodrug, Al-ProD, that consists of a albumin-binding maleimide group, cathepsin B-cleavable peptide (FRRG), and doxorubicin.

Visible-Light-Triggered Prodrug Nanoparticles Combine Chemotherapy and Photodynamic Therapy to Potentiate Checkpoint Blockade Cancer Immunotherapy.

Immune checkpoint blockade is a promising approach for cancer immunotherapy, but many patients do not respond due to the immunosuppressive tumor microenvironment (ITM). Herein, we propose visible-light-triggered prodrug nanoparticles (LT-NPs) for reversing ITM into high immunogenic tumors to potentiate checkpoint blockade immunotherapy. The photosensitizer (verteporfin; VPF), cathepin B-specific cleavable peptide (FRRG), and doxorubicin (DOX) conjugates are self-assembled into LT-NPs without any additional carrier material.

Rediscovery of nanoparticle-based therapeutics: boosting immunogenic cell death for potential application in cancer immunotherapy.

Immunogenic cell death (ICD) occurring by chemical and physical stimuli has shown the potential to activate an adaptive immune response in the immune-competent living body through the release of danger-associated molecular patterns (DAMPs) into the tumor microenvironment (TME). However, limitations to the long-term immune responses and systemic toxicity of conventional ICD inducers have led to unsatisfactory therapeutic efficacy in ICD-based cancer immunotherapy. Until now, various nanoparticle-based ICD-inducers have been developed to induce an antitumor immune response without severe toxicity, and to efficiently elicit an anticancer immune response against target cancer cells.

Cancer-activated doxorubicin prodrug nanoparticles induce preferential immune response with minimal doxorubicin-related toxicity.

The effective chemotherapeutic drug, doxorubicin (DOX), elicits immunogenic cell death (ICD) and additional anticancer immune responses during chemotherapy. However, it also induces severe side effects and systemic immunosuppression, hampering its wide clinical application. Herein, we constructed cancer-activated DOX prodrug by conjugating the cathepsin B-cleavable peptide (Phe-Arg-Arg-Gly, FRRG) to a doxorubicin (DOX), resulting in FRRG-DOX that self-assembled into cancer-activated DOX prodrug nanoparticles (CAP-NPs).

Doxorubicin-Loaded PLGA Nanoparticles for Cancer Therapy: Molecular Weight Effect of PLGA in Doxorubicin Release for Controlling Immunogenic Cell Death.

Direct local delivery of immunogenic cell death (ICD) inducers to a tumor site is an attractive approach for leading ICD effectively, due to enabling the concentrated delivery of ICD inducers to the tumor site. Herein, we prepared doxorubicin (DOX)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) using different molecular weight PLGA (7000 g/mol and 12,000 g/mol), showing different drug release kinetics. The different release kinetics of DOX might differently stimulate a tumor cell-specific immune response by releasing damage-associated molecular patterns (DAMPs), resulting in showing a different antitumor response in the living body.

Combination of cancer-specific prodrug nanoparticle with Bcl-2 inhibitor to overcome acquired drug resistance.

Multiple combination therapies with chemotherapeutic drugs and inhibitors of drug resistance have been effective in the clinical cases, but concerns have been raised about the severe toxicity of these chemotherapeutic drugs. Herein, we report a potent and safe combination strategy of cancer-specific doxorubicin (DOX) prodrug nanoparticles (PNPs) and B-cell lymphoma-2 (Bcl-2) anti-apoptotic inhibitor, Navitoclax, to overcome acquired drug resistance during chemotherapy. The cancer-specific PNPs were constructed by conjugating cathepsin B-specific cleavable peptide (Phe-Arg-Arg-Gly; FRRG) to DOX, resulting in FRRG-DOX that self-assembled into nanoparticles and the FRRG-DOX nanoparticles were further stabilized with the FDA-approved pharmaceutical excipient, Pluronic F68.

Predicting in vivo therapeutic efficacy of bioorthogonally labeled endothelial progenitor cells in hind limb ischemia models via non-invasive fluorescence molecular tomography.

Human embryonic stem cells-derived endothelial progenitor cells (hEPCs) were utilized as cell therapeutics for the treatment of ischemic diseases. However, in vivo tracking of hEPCs for predicting their therapeutic efficacy is very difficult. Herein, we developed bioorthogonal labeling strategy of hEPCs that could non-invasively track them after transplantation in hind limb ischemia models.

Cancer-specific drug-drug nanoparticles of pro-apoptotic and cathepsin B-cleavable peptide-conjugated doxorubicin for drug-resistant cancer therapy.

Chemotherapy has shown remarkable therapeutic efficacy for various types of cancer. However, drug resistance reduces the effectiveness and sensitivity of chemotherapy, leading treatment failure and cancer relapse in many clinical indications. Herein, we propose cancer-specific drug-drug nanoparticles (DD-NPs) that improve the therapeutic efficacy of chemotherapy against drug-resistant cancer.

Epidermal growth factor (EGF)-based activatable probe for predicting therapeutic outcome of an EGF-based doxorubicin prodrug.

One of the most promising approaches for the treatment of colorectal cancer is targeting epidermal growth factor receptor (EGFR). Comprehensive research has led to significant clinical outcomes using EGFR-targeted anticancer drugs; however, the response to these drugs still largely varies among individuals. The current diagnostic platform provides limited information that does not enable successful prediction of the anticancer performance of EGFR-targeted drugs.

In Situ One-Step Fluorescence Labeling Strategy of Exosomes via Bioorthogonal Click Chemistry for Real-Time Exosome Tracking In Vitro and In Vivo.

Exosomes are cellular components with promising uses in cancer diagnostics and therapeutics, and their imaging and tracking are essential to study their biological properties. Herein, we report on an in situ one-step fluorescence labeling strategy for exosomes via bioorthogonal click chemistry. First, exosome donor cancer cells were treated with tetraacetylated -azidoacetyl-d-mannosamine (AcManNAz) to generate unnatural azide groups (-N) on their surface via metabolic glycoengineering.

Necroptosis-Inducible Polymeric Nanobubbles for Enhanced Cancer Sonoimmunotherapy.

Necroptosis, caspase-independent programmed necrosis, has emerged as a therapeutic target to make dying cancer cells stimulants for antitumor immune responses. The clinical translations exploiting necroptosis, however, have been limited since most cancer cells downregulate receptor-interacting protein kinase 3 (RIPK3) as a key enzyme for necroptosis. Herein, nanobubbles (NBs) that can trigger RIPK3-independent necroptosis, facilitating cell-membrane rupture via the acoustic cavitation effect are reported.