Enhanced Permeability And Retention Research Articles

Bioinspired Adaptive Microdrugs Enhance the Chemotherapy of Malignant Glioma: Beyond Their Nanodrugs.

Solid nanoparticle-mediated drug delivery systems are usually confined to nanoscale due to the enhanced permeability and retention (EPR) effect. However, they remain a great challenge for malignant glioma chemotherapy because of poor drug delivery efficiency and insufficient tumor penetration resulting from the blood-brain barrier/blood-brain tumor barrier (BBB/BBTB). Inspired by biological microparticles (e.g., cells) with excellent adaptive deformation, we demonstrate that the adaptive microdrugs (even up to 3.0μm in size) are more efficient than their nanodrugs (less than 200nm in size) to cross BBB/BBTB and penetrate into tumor tissues, achieving highly efficient chemotherapy of malignant glioma. The distinct delivery of the adaptive microdrugs is mainly attributed to the enhanced interfacial binding and endocytosis via adaptive deformation. As expected, the obtained adaptive microdrugs exhibited enhanced accumulation, deep penetration, and cellular internalization into tumor tissues in comparison with nanodrugs, significantly improving the survival rate of glioblastoma mice. We believe that the bioinspired adaptive microdrugs enable them to efficiently cross physiological barriers and deeply penetrate tumor tissues for drug delivery, providing an avenue for the treatment of solid tumors. This article is protected by copyright. All rights reserved.

Receptor Ligand-Free Mesoporous Silica Nanoparticles: A Streamlined Strategy for Targeted Drug Delivery across the Blood-Brain Barrier.

Mesoporous silica nanoparticles (MSNs) represent a promising avenue for targeted brain tumor therapy. However, the blood-brain barrier (BBB) often presents a formidable obstacle to efficient drug delivery. This study introduces a ligand-free PEGylated MSN variant (RMSN25-PEG-TA) with a 25 nm size and a slight positive charge, which exhibits superior BBB penetration. Utilizing two-photon imaging, RMSN25-PEG-TA particles remained in circulation for over 24 h, indicating significant traversal beyond the cerebrovascular realm. Importantly, DOX@RMSN25-PEG-TA, our MSN loaded with doxorubicin (DOX), harnessed the enhanced permeability and retention (EPR) effect to achieve a 6-fold increase in brain accumulation compared to free DOX. In vivo evaluations confirmed the potent inhibition of orthotopic glioma growth by DOX@RMSN25-PEG-TA, extending survival rates in spontaneous brain tumor models by over 28% and offering an improved biosafety profile. Advanced LC-MS/MS investigations unveiled a distinctive protein corona surrounding RMSN25-PEG-TA, suggesting proteins such as apolipoprotein E and albumin could play pivotal roles in enabling its BBB penetration. Our results underscore the potential of ligand-free MSNs in treating brain tumors, which supports the development of future drug-nanoparticle design paradigms.

Prostate-Specific Membrane Antigen Targeted StarPEG Nanocarrier for Imaging and Therapy of Prostate Cancer.

The uptake of large (>10nm) non-targeted nanocarriers by bulk tumors is thought to be dominated by passive extravasation through porous tumor vessels and limited lymphatic drainage, the enhanced permeability and retention (EPR) effect. Prior studies demonstrated radiolabeled tumor-targeted and non-targeted 4-arm 40kDa star polyethylene glycol (StarPEG) polymers for cancer imaging. By adding small molecule ligands targeting prostate-specific membrane antigen (PSMA) to the StarPEG polymer, marked increase in tumor uptake, penetration and retention in the tumor core was observed. These prior studies support the application of imaging surrogates for the evaluation of targeted delivery of chemotherapeutic nanomedicines and the potential for therapy using analogous β-emitting radiopharmaceuticals. To evaluate the delivery and therapeutic efficacy of PSMA-targeted StarPEG nanocarriers, StarPEG nanodrugs with or without three copies of PSMA-targeting, ACUPA, ligands were designed and synthesized. One copy of the radiometal chelator, DOTA, was conjugated to each nanocarrier for labelling with b-emitting 177Lu, providing non-targeted [177Lu]PEG-(DOTA)1 and PSMA targeting [177Lu]PEG-(DOTA)1(ACUPA)3, for SPECT imaging and therapy. The radiolabeled nanodrugs were evaluated in vitro and in vivo using PSMA+ PC3-Pip and/or PSMA- PC3-Flu cell lines, subcutaneous xenografts and disseminated metastatic models. The nanocarriers PEG-(DOTA)1 and PEG-(DOTA)1(ACUPA)3 were efficiently radiolabeled with 177Lu with molar activities of 10.8-15.8 MBq/nmol. Along with excellent in vitro PSMA binding affinity (kD = 51.7nM in PC3-Pip cells), the targeted nanocarrier [177Lu]PEG-(DOTA)1(ACUPA)3 demonstrated excellent in vivo single-photon emission computed tomography (SPECT) imaging contrast with 21.3% ID/g uptake in PC3-Pip tumors at 192h post injection. Single doses of 18.5 MBq [177Lu]PEG-(DOTA)1(ACUPA)3 showed complete resolution of the PC3-Pip xenografts, without any regrowth up to 138 days. The StarPEG nanocarriers demonstrated high PSMA-targeted delivery of the therapeutic isotope 177Lu with excellent imaging contrast. The targeted nanocarrier eliminated subcutaneous and metastatic PC3-Pip tumors. Overall, these preclinical results demonstrated high treatment efficacy of the PSMA-targeted nanocarrier [177Lu]PEG-(DOTA)1(ACUPA)3 for prostate cancer, with potential for clinical translation. This article is protected by copyright. All rights reserved.

A lava-inspired proteolytic enzyme therapy on cancer with a PEG-based hydrogel enhances tumor distribution and penetration of liposomes

The enhanced permeability and retention (EPR) effect has become the guiding principle for nanomedicine against cancer for a long time. However, several biological barriers severely resist therapeutic agents’ penetration and retention into the deep tumor tissues, resulting in poor EPR effect and high tumor mortality. Inspired by lava, we proposed a proteolytic enzyme therapy to improve the tumor distribution and penetration of nanomedicine. A trypsin-crosslinked hydrogel (Trypsin@PSA Gel) was developed to maintain trypsin’s activity. The hydrogel postponed trypsin’s self-degradation and sustained the release. Trypsin promoted the cellular uptake of nanoformulations in breast cancer cells, enhanced the penetration through endothelial cells, and degraded total and membrane proteins. Proteomic analysis reveals that trypsin affected ECM components and down-regulated multiple pathways associated with cancer progression. Intratumoral injection of Trypsin@PSA Gel significantly increased the distribution of liposomes in tumors and reduced tumor vasculature. Combination treatment with intravenous injection of gambogic acid-loaded liposomes and intratumoral injection of Trypsin@PSA Gel inhibited tumor growth. The current study provides one of the first investigations into the enhanced tumor distribution of liposomes induced by a novel proteolytic enzyme therapy.Graphic

Therapeutic Applications of Nanomedicine: Recent Developments and Future Perspectives.

The concept of nanomedicine has evolved significantly in recent decades, leveraging the unique phenomenon known as the enhanced permeability and retention (EPR) effect. This has facilitated major advancements in targeted drug delivery, imaging, and individualized therapy through the integration of nanotechnology principles into medicine. Numerous nanomedicines have been developed and applied for disease treatment, with a particular focus on cancer therapy. Recently, nanomedicine has been utilized in various advanced fields, including diagnosis, vaccines, immunotherapy, gene delivery, and tissue engineering. Multifunctional nanomedicines facilitate concurrent medication delivery, therapeutic monitoring, and imaging, allowing for immediate responses and personalized treatment plans. This review concerns the major advancement of nanomaterials and their potential applications in the biological and medical fields. Along with this, we also mention the various clinical translations of nanomedicine and the major challenges that nanomedicine is currently facing to overcome the clinical translation barrier.

Novel strategies for enhanced fluorescence visualization of glioblastoma tumors based on HPMA copolymers conjugated with tumor targeting and/or cell‐penetrating peptides

AbstractNano‐sized polymer systems are often used as carriers for drugs and contrast agents to increase circulation time and solubility and to reduce possible side effects. These nanomedicines usually accumulate in tumor tissue due to the enhanced permeability and retention (EPR) effect. However, a targeting group may be attached to the polymer carrier in addition to the active substance to further increase tumor accumulation and specificity. In this study, the oligopeptide sequence RGD was chosen to target αvβ3 integrins overexpressed in the tumor vasculature and on some tumor cells. A set of polymer conjugates bearing a fluorescent dye and RGD peptide of different structures (linear, cyclic, branched) was prepared for use in tumor diagnosis, with a potential future application in navigated surgery. The accumulation of the most promising candidate, a targeted fluorescent nanoprobe, increased by 35% in glioblastoma tumors compared to the non‐targeted control, which accumulated only due to the EPR effect. However, the administration of a polymer‐bound modified cilengitide as an antiangiogenic treatment did not show a beneficial effect in the suppression of angiogenesis.

Codelivery of CPT and siPHB1 with GSH/ROS Dual-Responsive Hybrid Nanoparticles Based on a [12]aneN3-Derived Lipid for Synergistic Lung Cancer Therapy.

The combination of small-interfering RNA (siRNA)-mediated gene silencing and chemotherapeutic agents for lung cancer treatment has attracted widespread attention in terms of a greater therapeutic effect, minimization of systemic toxicity, and inhibition of multiple drug resistance (MDR). In this work, three amphiphiles, CBN1-CBN3, were first designed and synthesized as a camptothecin (CPT) conjugate and gene condensation agents by the combination of CPT prodrugs and di(triazole-[12]aneN3) through the ROS-responsive phenylborate ester and different lengths of alkyl chains (with 6, 9, 12 carbon chains for CBN1-CBN3, respectively). CBN1-CBN3 were able to be self-assembled into liposomes with an average diameter in the range of 320-240 nm, showing the ability to effectively condense siRNA. Among them, CBN2, with a nine-carbon alkyl chain, displayed the best anticancer efficiency in A549 cells. In order to give nanomedicines a stealth property and PEGylation/dePEGylation transition, a GSH-responsive PEGylated TPE derivative containing a disulfide linkage (TSP) was further designed and prepared. A combination of CBN2/siRNA complexes and DOPE with TSP resulted in GSH/ROS dual-responsive lipid-polymer hybrid nanoparticles (CBN2-DP/siRNA NPs). In present GSH and H2O2, CBN2-DP/siRNA NPs were decomposed, resulting in the controlled release of CPT drug and siRNA. In vitro, CBN2-DP/siPHB1 NPs showed the best anticancer activity for suppression of about 75% of A549 cell proliferation in a serum medium. The stability of CBN2-DP/siRNA NPs was significantly prolonged in blood circulation, and they showed effective accumulation in the A549 tumor site through an enhanced permeability and retention (EPR) effect. In vivo, CBN2-DP/siPHB1 NPs demonstrated enhanced synergistic cancer therapy efficacy and tumor inhibition as high as 71.2%. This work provided a strategy for preparing lipid-polymer hybrid NPs with GSH/ROS dual-responsive properties and an intriguing method for lung cancer therapy.

Self-Assembled Matrine-PROTAC Encapsulating Zinc(II) Phthalocyanine with GSH-Depletion-Enhanced ROS Generation for Cancer Therapy.

The integration of a multidimensional treatment dominated by active ingredients of traditional Chinese medicine (TCM), including enhanced chemotherapy and synergistically amplification of oxidative damage, into a nanoplatform would be of great significance for furthering accurate and effective cancer treatment with the active ingredients of TCM. Herein, in this study, we designed and synthesized four matrine-proteolysis-targeting chimeras (PROTACs) (depending on different lengths of the chains named LST-1, LST-2, LST-3, and LST-4) based on PROTAC technology to overcome the limitations of matrine. LST-4, with better anti-tumor activity than matrine, still degrades p-Erk and p-Akt proteins. Moreover, LST-4 NPs formed via LST-4 self-assembly with stronger anti-tumor activity and glutathione (GSH) depletion ability could be enriched in lysosomes through their outstanding enhanced permeability and retention (EPR) effect. Then, we synthesized LST-4@ZnPc NPs with a low-pH-triggered drug release property that could release zinc(II) phthalocyanine (ZnPc) in tumor sites. LST-4@ZnPc NPs combine the application of chemotherapy and phototherapy, including both enhanced chemotherapy from LST-4 NPs and the synergistic amplification of oxidative damage, through increasing the reactive oxygen species (ROS) by photodynamic therapy (PDT), causing an GSH decrease via LST-4 mediation to effectively kill tumor cells. Therefore, multifunctional LST-4@ZnPc NPs are a promising method for killing cancer cells, which also provides a new paradigm for using natural products to kill tumors.

Abstract 5737: Enhancing cancer treatment Via a nanostructured chemoimmunotherapy gel facilitating interleukin-2 delivery and immunogenic cell death induction

Abstract Background: The landscape of immunotherapy, employing recombinant cytokines like interleukin-2 (IL-2), confronts challenges marked by its short half-life, systemic toxicity, and constrained tumor accumulation. These hurdles are particularly evident in the context of the immunosuppressive milieu characterizing pancreatic ductal adenocarcinoma (PDAC). Chemo-immuno-therapeutic synergies, notably those provoking immunogenic cell death (ICD), have demonstrated superior efficacy. This investigation delves into Pt-NHC as a type II ICD inducer to surmount immunosuppression and amplify antitumor immunity within a highly tumor-accumulated liposomal drug delivery system. Additionally, the co-administration of the angiotensin receptor blocker, losartan, mitigates desmoplasia in PDAC, further augmenting the efficacy of immunotherapy. Methods: To address the constraints of IL-2, a lipid-coated nanogel, IL2-Pt@Nanogel, was innovated, amalgamating silk fibroin-loaded IL-2 with Pt-NHC. The nanogel aimed to enhance IL-2 pharmacokinetics and optimize tumor targeting. Concurrently, losartan was employed to alleviate desmoplasia within the tumor microenvironment. Result: The chemoimmunotherapy nanogel, when coupled with losartan, showcased therapeutic potential in murine models of desmoplastic PDAC. Pt-NHC induced ER-localized reactive oxygen species (ROS) and DAMP release, reshaping the immunosuppressive microenvironment by repolarizing M2-type macrophages to M1 and diminishing the regulatory T-cell population. Co-delivery of IL-2 and Pt-NHC in the nanogel enhanced T-cell infiltration and activation, curbing tumor progression in primary and liver metastasized PDAC models. Importantly, the addition of losartan reduced collagen accumulation within tumors, resulting in heightened infiltration of effector T cells and more pronounced suppression of tumor growth in PDAC and metastasized liver. Conclusion: This study introduces an innovative nanogel delivery system (IL2-Pt@Nanogel) for chemoimmunotherapy, effectively addressing the challenges associated with IL-2 therapy. Leveraging the enhanced permeability and retention (EPR) effect, the nanogel improves IL-2 stability and tumor delivery. Pt-NHC incorporation induces ICD, reshaping the tumor microenvironment, and in synergy with losartan, elicits robust anticancer immunity. This strategy holds promise for clinical translation as a secure and efficient treatment for immunosuppressive and desmoplastic cancers, such as PDAC, presenting a distinctive therapeutic avenue. Citation Format: Hsuan Yu Mu, Yen-Nhi Ngoc Ta, Jing Rui Max Tham, Fu-Fei Hsu, Yu-Chieh Lin, Hsi-Chien Huang, Yun-Chieh Sung, Chih-I Huang, Ching-Ling Wu, Chao-Hung Chang, Sheng Yang, Tsung-Ying Lee, Jane Wang, Dan G. Duda, Yves Boucher, Jen-Huang Huang, Wee Han Ang, Yunching Chen. Enhancing cancer treatment Via a nanostructured chemoimmunotherapy gel facilitating interleukin-2 delivery and immunogenic cell death induction [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5737.

A quantitative MRI-based approach to estimate the permeation and retention of nanomedicines in tumors

Despite the potential of the enhanced permeability and retention (EPR) effect in tumor passive targeting, many nanotherapeutics have failed to produce meaningful clinical outcomes due to the variable and challenging nature of the tumor microenvironment (TME) and EPR effect. This EPR variability across tumors and inconsistent translation of nanomedicines from preclinical to clinical settings necessitates a reliable method to assess its presence in individual tumors. This study aimed to develop a reliable and non-invasive approach to estimate the EPR effect in tumors using a clinically compatible quantitative magnetic resonance imaging (qMRI) technique combined with a nano-sized MRI contrast agent. A quantitative MR imaging was developed using a dynamic contrast-enhanced (DCE) MRI protocol. Then, the permeability and retention of the nano-sized MRI contrast agent were evaluated in three different ovarian xenograft tumor models. Results showed significant differences in EPR effects among the tumor models, with tumor growth influencing the calculated parameters of permeability (Ktrans) and retention (Ve) based on Tofts pharmacokinetic (PK) modeling. Our data indicate that the developed quantitative DCE-MRI method, combined with the Tofts PK modeling, provides a robust and non-invasive approach to screen tumors for their responsiveness to nanotherapeutics. These results imply that the developed qMRI method can be beneficial for personalized cancer treatments by ensuring that nanotherapeutics are administered only to patients with tumors showing sufficient EPR levels.

Cancer cell-specific and pro-apoptotic SMAC peptide-doxorubicin conjugated prodrug encapsulated aposomes for synergistic cancer immunotherapy

BackgroundImmunogenic cell death (ICD) is a crucial approach to turn immunosuppressive tumor microenvironment (ITM) into immune-responsive milieu and improve the response rate of immune checkpoint blockade (ICB) therapy. However, cancer cells show resistance to ICD-inducing chemotherapeutic drugs, and non-specific toxicity of those drugs against immune cells reduce the immunotherapy efficiency.MethodsHerein, we propose cancer cell-specific and pro-apoptotic liposomes (Aposomes) encapsulating second mitochondria-derived activator of caspases mimetic peptide (SMAC-P)-doxorubicin (DOX) conjugated prodrug to potentiate combinational ICB therapy with ICD. The SMAC-P (AVPIAQ) with cathepsin B-cleavable peptide (FRRG) was directly conjugated to DOX, and the resulting SMAC-P-FRRG-DOX prodrug was encapsulated into PEGylated liposomes.ResultsThe SMAC-P-FRRG-DOX encapsulated PEGylated liposomes (Aposomes) form a stable nanostructure with an average diameter of 109.1 ± 5.14 nm and promote the apoptotic cell death mainly in cathepsin B-overexpressed cancer cells. Therefore, Aposomes induce a potent ICD in targeted cancer cells in synergy of SMAC-P with DOX in cultured cells. In colon tumor models, Aposomes efficiently accumulate in targeted tumor tissues via enhanced permeability and retention (EPR) effect and release the encapsulated prodrug of SMAC-P-FRRG-DOX, which is subsequently cleaved to SMAC-P and DOX in cancer cells. Importantly, the synergistic activity of inhibitors of apoptosis proteins (IAPs)-inhibitory SMAC-P sensitizing the effects of DOX induces a potent ICD in the cancer cells to promote dendritic cell (DC) maturation and stimulate T cell proliferation and activation, turning ITM into immune-responsive milieu.ConclusionsEventually, the combination of Aposomes with anti-PD-L1 antibody results in a high rate of complete tumor regression (CR: 80%) and also prevent the tumor recurrence by immunological memory established during treatments.Graphical

Light-activated NIR-II imaging-guided tumor therapy with enhanced HPTT/starvation cycle

Establishing a phototheranostic platform constructed by the second near-infrared (NIR-II) region has proved a revolutionary and promising strategy for cancer treatment. However, the antitumor effectiveness is severely limited by the monotonicity of the NIR-photothermal therapy (HPTT) modality and tumor thermotolerance caused by the production of heat shock proteins (HSPs). Here, a minimalistic approach is used to construct an organic nanoplatform (IFT@PEG-GOX NPs) with the reciprocal cyclic promotion of hypothermia and starvation treatments for NIR-II imaging-guided tumor therapy. After the enhanced permeability and retention (EPR) effect causes IFT@PEG-GOX NPs to accumulate in tumors, glucose oxidase (GOx)-mediated tumor starvation may obstruct the production of adenosine triphosphate (ATP) and downregulation heat shock proteins (HSPs), thereby reducing the thermotolerance of cells. After that, sensitized HPTT was activated and GOx's catalytic activity was increased by NIR laser irradiation. Then, there would be a subsequent, intensified inhibition of HSP along with an additional amplification of the GOx-mediated tumor starvation. As a consequence, the HPTT/Starvation therapy (ST) bidirectional cycle method is initiated, leading to a bidirectional cyclic enhancing impact of HPTT and ST and significantly better tumor suppression.

Nanoparticle drug delivery systems responsive to tumor microenvironment: Promising alternatives in the treatment of triple-negative breast cancer.

The conventional therapeutic treatment of triple-negative breast cancer (TNBC) is negatively influenced by the development of tumor cell drug resistant, and systemic toxicity of therapeutic agents due to off-target activity. In accordance with research findings, nanoparticles (NPs) responsive to the tumor microenvironment (TME) have been discovered for providing opportunities to selectively target tumor cells via active targeting or Enhanced Permeability and Retention (EPR) effect. The combination of the TME control and therapeutic NPs offers promising solutions for improving the prognosis of the TNBC because the TME actively participates in tumor growth, metastasis, and drug resistance. The NP-based systems leverage stimulus-responsive mechanisms, such as low pH value, hypoxic, excessive secretion enzyme, concentration of glutathione (GSH)/reactive oxygen species (ROS), and high concentration of Adenosine triphosphate (ATP) to combat TNBC progression. Concurrently, NP-based stimulus-responsive introduces a novel approach for drug dosage design, administration, and modification of the pharmacokinetics of conventional chemotherapy and immunotherapy drugs. This review provides a comprehensive examination of the strengths, limitations, applications, perspectives, and future expectations of both novel and traditional stimulus-responsive NP-based drug delivery systems for improving outcomes in the medical practice of TNBC. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Modulation of the Tumor Stroma and Associated Novel Nanoparticle Strategies to Enhance Tumor Targeting

Growth of malignant cells in solid tumors induces changes to the tumor microenvironment (TME). These changes result in promotion of tumor growth, invasion, and metastasis, but also in tumor resistance to drugs and radiotherapy. The enhanced permeability and retention (EPR) effect in neo-angiogenic tumor tissue enables the transport of therapeutic molecules from the circulation into the tumor, but studies show that further diffusion of these agents is often not sufficient for efficient tumor eradication. Despite the hyperpermeable vasculature facilitating the delivery of drugs and tracers, the high density of stromal cells and matrix proteins, in combination with the elevated interstitial fluid pressure in the microenvironment of solid tumors, presents a barrier which limits the delivery of compounds to the core of the tumor. Reversing the cancer-cell-induced changes to the microenvironment as well as novel nanoparticle strategies to circumvent tumor-induced stromal changes have therefore been suggested as potential methods to improve the delivery of therapeutic molecules and drug efficacy. Strategies to modulate the TME, i.e., normalization of tumor vasculature and depletion of excessive stromal proteins and cells, show promising results in enhancing delivery of therapeutic compounds. Modulation of the TME may therefore enhance the efficacy of current cancer treatments and facilitate the development of novel treatment methods as an alternative for invasive resection procedures.

Biogenic Synthesis and Characterization of Ethyl Ferulate Gold Nanoparticle and its Efficacy against Triple-Negative Breast Cancer Cells

Background: Triple-Negative Breast Cancer (TNBC) presents a significant challenge due to its aggressive nature and lack of responsive hormone receptors, predominantly affecting younger premenopausal women. Ethyl ferulate (EF), a notable phytochemical, has demonstrated promising anti-cancer properties. This study aimed to enhance the efficacy of EF by synthesizing and characterizing ethyl ferulate gold nanoparticles (EF-AuNps) to passively target TNBC cells via the enhanced permeability and retention (EPR) effect. Methods: We synthesized EF-AuNps using a direct reduction method and characterized the NPs by employing various techniques, including UV-visible spectroscopy, DLS, XRD, EDX, TEM, and FT-IR. The anti-proliferative activity against MDA-MB-231 cells was assessed using MTT and colony formation assays, alongside evaluating cell viability with PI-FACS and live/dead assays. Furthermore, a Western blot was performed to determine the mechanism of action of EFAuNps in TNBC cells. Result: We successfully synthesized triangular EF-AuNps (<100nm) and observed a substantial inhibition of cell proliferation (IC50 18μg/ml). Compared to EF alone, EF-AuNps significantly enhanced cell death in TNBC cells, as confirmed by flow cytometry and viability assays. Besides, Western blot analysis verified that the expression of apoptotic-related signal proteins, such as survivin, caspase 3, and caspase 9, were modulated by EF-AuNps. Conclusion: EF-AuNps showed higher anti-cancer efficacy than EF in the MDA-MB-231 cell line. These findings suggest the therapeutic potential of EF-AuNps for TNBC treatment, advocating for further preclinical and clinical investigations into this promising anti-cancer formulation.

An Efficient Strategy for Constructing Fluorescent Nanoprobes for Prolonged and Accurate Tumor Imaging.

Activatable near-infrared (NIR) fluorescent probes possess advantages of high selectivity, sensitivity, and deep imaging depth, holding great potential in the early diagnosis and prognosis assessment of tumors. However, small-molecule fluorescent probes are largely limited due to the rapid diffusion and metabolic clearance of activated fluorophores in vivo. Herein, we propose an efficient and reproducible novel strategy to construct activatable fluorescent nanoprobes through bioorthogonal reactions and the strong gold-sulfur (Au-S) interactions to achieve an enhanced permeability and retention (EPR) effect, thereby achieving prolonged and high-contrast tumor imaging in vivo. To demonstrate the merits of this strategy, we prepared an activatable nanoprobe, hCy-ALP@AuNP, for imaging alkaline phosphatase (ALP) activity in vivo, whose nanoscale properties facilitate accumulation and long-term retention in tumor lesions. Tumor-overexpressed ALP significantly increased the fluorescence signal of hCy-ALP@AuNP in the NIR region. More importantly, compared with the small-molecule probe hCy-ALP-N3, the nanoprobe hCy-ALP@AuNP significantly improved the distribution and retention time in the tumor, thus improving the imaging window and accuracy. Therefore, this nanoprobe platform has great potential in the efficient construction of biomarker-responsive fluorescent nanoprobes to realize precise tumor diagnosis in vivo.

Novel Carrier-Free Nanodrug Enhances Photodynamic Effects by Blocking the Autophagy Pathway and Synergistically Triggers Immunogenic Cell Death for the Efficient Treatment of Breast Cancer.

Photosensitizers have been widely used to cause intratumoral generation of reactive oxygen species (ROS) for cancer therapy, but they are easily disturbed by the autophagy pathway, a self-protective mechanism by mitigating oxidative damage. Hereby, we reported a simple and effective strategy to construct a carrier-free nanodrug, Ce6@CQ namely, based on the self-assembly of the photosensitizer chlorin e6 (Ce6) and the autophagy inhibitor chloroquine (CQ). Specifically, Ce6@CQ avoided the unexpected toxicity caused by the regular nanocarrier and also ameliorated its stability in different conditions. Light-activated Ce6 generated cytotoxic ROS and elicited part of the immunogenic cell death (ICD). Moreover, CQ induced autophagy dysfunction, which hindered self-healing in tumor cells and enhanced photodynamic therapy (PDT) to exert a more potent killing effect and more efficient ICD. Also, Ce6@CQ could effectively accumulate in the xenograft breast tumor site in a mouse model through the enhanced permeability and retention (EPR) effect, and the growth of breast tumors was effectively inhibited by Ce6@CQ with light. Such a carrier-free nanodrug provided a new strategy to improve the efficacy of PDT via the suppression of autophagy to digest ROS-induced toxic substances.

Novel nanotherapeutics for cancer immunotherapy by albumin nanoparticles functionalized with PD-1 and PD-L1 aptamers

BackgroundPD-1/PD-L1 blockade plays a crucial role in cancer immunotherapy. Exploration of new technologies to further enhance the efficacy of PD-1/PD-L1 blockade is therefore of potential medical importance. Nanotherapeutics can accumulate in tumor tissues due to enhanced permeability and retention (EPR) effects. In this study, a novel nanotherapeutic for cancer immunotherapy was implemented with albumin nanoparticles functionalized by both PD-1 and PD-L1 aptamers.ResultsAlbumin nanoparticles (NP) were functionalized with either PD-1 aptamers (PD1-NP), PD-L1 aptamers (PDL1-NP), or both types of aptamers (PD1-NP-PDL1). Average sizes of PD1-NP, PDL1-NP, and PD1-NP-PDL1 were 141.8 nm, 141.8 nm, and 164.2 nm, respectively. PD1-NP had good affinity for activated T cells that expresses PD-1. Similarly, PDL1-NP could bind with MDA-MB-231 or CT26 tumor cells that express PD-L1. Moreover, the bispecific PD1-NP-PDL1 could bind with both the activated T cells and the PD-L1-expressing tumor cells, and tether the two type of cells together. Functionally, aptamer-modified nanoparticles exhibited stronger immune-stimulating effects vs. free aptamers. Specifically, PD1-NP or PDL1-NP induced stronger lymphocyte-mediated cytotoxicity against PD-L1-expressing tumor cells in vitro vs. free PD-1 or PD-L1 aptamers. Animal studies also showed that PD1-NP or PDL1-NP significantly improved antitumor efficacy against CT26 colon cancer in vivo vs. free PD-1 or PD-L1 aptamers. Importantly, the bispecific PD1-NP-PDL1 further boosted the in vivo antitumor efficacy compared with PD1-NP or PDL1-NP, without raising systemic toxicity.ConclusionThe results suggest that the bispecific PD1-NP-PDL1 is a promising nanotherapeutic to improve the efficacy of PD-1/PD-L1 blockade, and may have application potential in colon cancer treatment.

Site-specific controlled-release nanoparticles for immune reprogramming via dual metabolic inhibition against triple-negative breast cancer

Metabolic heterogeneity and the tumor immunosuppressive microenvironment (TIME) of triple-negative breast cancer (TNBC) hinder therapeutic effectiveness. Although emerging metabolic therapy and immunotherapy show promise, they are limited by off-target effects and immune escape. Here, a redox-activatable, sequentially-releasing nanoparticle (AMANC@M) for tumor-targeted delivery of anticancer agents and CRISPR/Cas9 has been developed. AMANC@M can reverse the TIME through dual metabolic inhibition, thereby enhancing TNBC therapy. AMANC@M demonstrates excellent biosafety and targets tumors precisely through biomimetic hybrid membrane-mediated homologous homing and the enhanced permeability and retention (EPR) effect. Once internalized into tumor cells, the CRISPR/Cas9 system (“energy nanolock”) is released through glutathione (GSH) cleavage and effectively knocks down the expression of lactate dehydrogenase A (LDHA) to suppress glycolysis. After peeling off of the gene editing shell, a newly synthesized targeted drug, CPI-Z2 (“nutrihijacker” and “energy nanolock”), is released in a controlled manner to block the mitochondrial tricarboxylic acid (TCA) cycle. Nitric oxide (NO) produced from loaded L-arginine enhances the efficiency of CPI-Z2 and reduces drug resistance. Combined with NO therapy, both blockades of nutrients and energy production transform the hypoxia and acidic TIME into an immunocompetent tumor microenvironment (TME) for tumor elimination. Furthermore, AMANC@M offers capabilities for photothermal (PT) therapy and provides clear imaging through PT, photoacoustic (PA), or computed tomography (CT) signals in tumor tissue. Thus, this study provides a new and promising sequentially stimuli-responsive targeting strategy for nanoparticle development, making it a potential treatment candidate for TNBC and other tumors.

A lipo-polymeric hybrid nanosystem with metal enhanced fluorescence for targeted imaging of metastatic breast cancer.

Cancer metastasis plays a major role in failure of therapeutic avenues against cancer. Owing to metastasis, nearly 70-80% of stage IV breast cancer patients lose their lives. Nanodrug delivery systems are playing a critical role in the therapy of metastatic cancer in the recent times. This paper reports the enhanced permeation and retention (EPR) based targeting of metastatic breast cancer using a novel nano lipo-polymeric system (PIR-Au NPs). The PIR-Au NPs demonstrated an increase in fluorescence by virtue of surface coating with gold, owing to the metal enhanced fluorescence phenomenon as reported in our earlier reports. Enhanced fluorescence of PIR-Au NPs was observed in murine mammary carcinoma cell line (4T1), as compared to free IR780 or IR780 loaded nanosystems (P-IR NPs), when incubated for same time at same concentrations, indicating its potential application for imaging and an enhanced bioavailability of IR780. Significant cell death was noted with photothermal mediated cytotoxicity in-vitro against breast cancer cells (MCF-7 and 4T1). An enhanced fluorescence was observed in the zebra fish embryos incubated with PIR-Au NPs. The enhanced permeation and retention (EPR) effect was seen with PIR-Au NPs in-vivo. A strong fluorescent signal was recorded in mice injected with PIR-Au NPs. The tumor tissue collected after 72 h, clearly showed a greater fluorescence as compared to other groups, indicating the plasmon enhanced fluorescence. We also demonstrated the EPR-based targeting of the PIR-Au NPs in-vivo by means of photothermal heat. This lipo-polymeric hybrid nanosystem could therefore be successfully applied for image-guided, passive-targeting to achieve maximum therapeutic benefits.