Tumor-penetrating peptide enhances transcytosis of silicasome-based chemotherapy for pancreatic cancer

Enhanced delivery of camptothecin to colorectal carcinoma using a tumor-penetrating peptide targeting p32

Camptothesome, a sphingomyelin (SM)-conjugated camptothecin (CPT) vesicular nanotherapeutic, addresses the poor solubility and lactone instability of CPT while enhancing drug loading, pharmacokinetics, and tumor distribution compared to CPT physically entrapped in conventional liposomes. Despite these improvements, the tumor uptake remains limited. To further enhance the tumor delivery efficiency and minimize the off-target distribution, we functionalize Camptothesome with the LinTT1 peptide, a CendR motif, which binds to overexpressed p32 proteins on tumor cell surface, initiating effective transcytosis for deep tumor penetration. Via systematic screening, the optimal peptide ratio on Camptothesome is identified. LinTT1/Camptothesome significantly increases cancer cell uptake without affecting normal cell internalization, resulting in enhanced anti-colorectal cancer cells activity. Additionally, decorating Camptothesome with the LinTT1 cell-penetrating peptide enables effective transcytosis via a Golgi-dependent intracellular trafficking mechanism, significantly improving the intratumoral delivery while reducing distribution to normal tissues. In a human HCT116 xenograft colorectal cancer (CRC) mouse model, LinTT1/Camptothesome demonstrates superior antitumor efficacy compared to both Camptothesome and Onivyde by upregulating cleaved caspase-3 and γH2AX. Our study substantiates the potential of leveraging a tumor-penetrating peptide to enhance the tumor delivery efficiency of Camptothesome, maximizing its therapeutic index for improved treatment of human CRC. STATEMENT OF SIGNIFICANCE: Despite the improved tumor delivery achieved by Camptothesome, its tumor distribution and penetration remain limited. This is because the enhanced permeability and retention effect only facilitates nanotherapeutic distribution to tumor periphery through leaky vasculature. The C-end Rule (CendR) motif-neuropilin receptor system enhances tumor-homing peptides by binding to cellular surface receptors, triggering transcytosis. Herein, LinTT1, the most potent CendR peptide that binds to the overexpressed p32 receptor on cancer cells, was effectively engineered onto Camptothesome using thiol-maleimide lipid chemistry. The LinTT1/Camptothesome significantly enhanced tumor uptake and penetration while minimizing accumulation in normal tissues, demonstrating remarkable anticancer efficacy in a human xenograft colorectal cancer model. Our findings highlight the critical role of tumor-homing peptides in unlocking the full therapeutic potential of Camptothesome.

Biomimetic nanosystems for pancreatic cancer therapy: A review

Pancreatic cancer (PC) is a highly lethal and aggressive malignancy, currently one of the leading causes of cancer-related deaths worldwide, in both women and men. PC is highly resistant to standard chemotherapy (CT) because its immunosuppressive and hypoxic tumor microenvironment and a dense desmoplastic stroma compartment extensively limit drug accessibility and perfusion. Although CT is one of the main therapeutic strategies for PC management contributing to tumor eradication through a cytotoxic effect, CT is associated with a poor pharmacokinetic profile and provokes deleterious systemic toxicity. This low efficacy-poor safety scenario urgently calls for innovative and highly specific therapeutic strategies to counteract this urgent clinical challenge. Nanotechnology-based precision materials for cancer may help improve drug stability and minimize the systemic cytotoxic effects by increasing drug tumor accumulation and also enabling controlled release, but several drawbacks still persist, such as the poor targeting efficiency. In the last few years increased attention has been paid to bioinspired nanosystems that can mimic either partially or totally biological systems, including lipid layers as suitable stealth coatings resembling the composition of cell membranes, lipoprotein- and blood protein-based nanosystems, and cell membrane-derived systems, such as extracellular vesicles, cell membrane nanovesicles and cell membrane-coated nanosystems, which display intrinsic cancer-targeting abilities, enhanced biocompatibility, decreased immunogenicity, and prolonged blood circulation profile. This review covers the recent breakthroughs on advanced biomimetic PC-targeted nanosystems, focusing on their design, properties and applications as innovative, multifunctional and versatile tools paving the way to improved PC diagnosis and treatment.

Beyond the EPR effect: Intravital microscopy analysis of nanoparticle drug delivery to tumors

Delivery of nanoparticles (NPs) to solid tumors has long relied on enhanced permeability and retention (EPR) effect, involving permeation of NPs through a leaky vasculature with prolonged retention by reduced lymphatic drainage in tumor. Recent research studies and clinical data challenge EPR concept, revealing alternative pathways and approaches of NP delivery. The area was significantly impacted by the implementation of intravital optical microscopy, unraveling delivery mechanisms at cellular level in vivo. This review presents analysis of the reasons for EPR heterogeneity in tumors and describes non-EPR based concepts for drug delivery, which can supplement the current paradigm. One of the approaches is targeting tumor endothelium by NPs with subsequent intravascular drug release and gradient-driven drug transport to tumor interstitium. Others exploit various immune cells for tumor infiltration and breaking endothelial barriers. Finally, we discuss the involvement of active transcytosis through endothelial cells in NP delivery. This review aims to inspire further understanding of the process of NP extravasation in tumors and provide insights for developing next-generation nanomedicines with improved delivery.

LRPPRC confers enhanced oxidative phosphorylation metabolism in triple-negative breast cancer and represents a therapeutic target

BACKGROUND

Triple-negative breast cancer (TNBC) is a highly malignant tumor that requires effective therapeutic targets and drugs. Oxidative phosphorylation (OXPHOS) is a metabolic vulnerability of TNBC, but the molecular mechanism responsible for the enhanced OXPHOS remains unclear. The current strategies that target the electronic transfer function of OXPHOS cannot distinguish tumor cells from normal cells. Investigating the mechanism underlying OXPHOS regulation and developing corresponding therapy strategies for TNBC is of great significance.

METHODS

Immunohistochemistry and sequencing data reanalysis were used to investigate LRPPRC expression in TNBC. In vitro and in vivo assays were applied to investigate the roles of LRPPRC in TNBC progression. RT-qPCR, immunoblotting, and Seahorse XF assay were used to examine LRPPRC's functions in the expression of OXPHOS subunits and energy metabolism. In vitro and in vivo functional assays were used to test the therapeutic effect of gossypol acetate (GAA), a traditional gynecological drug, on LRPPRC suppression and OXPOHS inhibition.

RESULTS

LRPPRC was specifically overexpressed in TNBC. LRPPRC knockdown suppressed the proliferation, metastasis, and tumor formation of TNBC cells. LRPPRC enhanced OXPHOS metabolism by increasing the expression of OXPHOS complex subunits encoded by the mitochondrial genome. GAA inhibited OXPHOS metabolism by directly binding LRPPRC, causing LRPPRC degradation, and downregulating the expression of OXPHOS complex subunits encoded by the mitochondrial genome. GAA administration suppressed TNBC cell proliferation, metastasis in vitro, and tumor formation in vivo.

CONCLUSIONS

This work demonstrated a new regulatory pathway of TNBC to promote the expression of mitochondrial genes by upregulating the nuclear gene LRPPRC, resulting in increased OXPHOS. We also suggested a promising therapeutic target LRPPRC for TNBC, and its inhibitor, the traditional gynecological medicine GAA, presented significant antitumor activity.

Silicasomes in Oncology: From Conventional Chemotherapy to Combined Immunotherapy

The use of nanoparticles as drug carriers in oncology has evolved from their traditional role as chemotherapy carriers to their application in immunotherapy, exploiting not only their passive accumulation in solid tumors but also their ability to interact with immune cells. Silicasomes are highly versatile nanoplatforms composed of a mesoporous silica core whose external surface is coated with a lipid bilayer that allows the co-delivery of therapeutic agents having different chemical natures (small molecules, proteins, enzymes, or oligonucleotides, among others). Herein, cutting-edge advances carried out in the development and application of silicasomes are presented, providing a general description of the performance of these nanotransporters. Additionally, the specific load of chemotherapeutic drugs is explored, followed by a discussion of the immunotherapeutic application of silicasomes and the combination of different therapeutic strategies, including theragnosis, in a single silicasome platform, highlighting the enormous potential of these nanosystems.

Population Pharmacokinetic Modeling of Certepetide in Human Subjects With Metastatic Pancreatic Ductal Adenocarcinoma

Certepetide (aka LSTA1 and CEND-1) is a novel cyclic tumor-targeting internalizing arginyl glycylaspartic acid peptide being developed to treat solid tumors. Certepetide is designed to overcome existing challenges in treating solid tumors by delivering co-administered anticancer drugs into the tumor while selectively depleting immunosuppressive T cells, enhancing cytotoxic T cells in the tumor microenvironment, and inhibiting the metastatic cascade. A population pharmacokinetic (PK) analysis was conducted to characterize the concentration-time profile of patients with metastatic exocrine pancreatic cancer receiving certepetide in combination with nab-paclitaxel and gemcitabine, and to investigate the effects of clinically relevant covariates on PK parameters. The PK of certepetide was characterized by a 2-compartment model with linear elimination and a proportional residual error structure. Body weight and baseline creatinine clearance (CrCL) were found to have statistically significant effects on central and peripheral volume (Vc and Vp) and clearance (CL) parameters, respectively, during model development and were included as covariate effects in the final PK model. Forest plots demonstrated a potentially clinically meaningful impact of high body weight (100 kg) on certepetide exposure (steady-state maximum concentration [Cmax,ss] and area under the concentration-time curve [AUCss]), as well as low and high CrCL (50 and 150 mL/min) on AUCss. Exposure predictions illustrated a relationship between certepetide exposure (AUCss) and renal function, with increasing exposure and decreasing CL of certepetide observed with worsening renal function. Modeling will strengthen the understanding of certepetide's PKs and will inform dose optimization in ongoing drug development activities.

Transcytosis: an effective mechanism to enhance nanoparticle extravasation and infiltration through biological barriers

Nanoparticles (NPs)1have been explored as drugs carriers for treating tumors and central nervous system (CNS)2diseases and for oral administration. However, they lack satisfactory clinical efficacy due to poor extravasation and infiltration through biological barriers to target tissues. Most clinical antitumor NPs have been designed based on enhanced permeability and retention effects which are insufficient and heterogeneous in human tumors. The tight junctions33TJs: tight junctionsof the blood-brain barrier44BBB: blood-brain barrierand the small intestinal epithelium severely impede NPs from being transported into the CNS and blood circulation, respectively. By contrast, transcytosis enables NPs to bypass these physiological barriers and enhances their infiltration into target tissues by active transport. Here, we systematically review the mechanisms and putative application of NP transcytosis for targeting tumor and CNS tissues, explore oral NP administration, and propose future research directions in the field of NP transcytosis.

iRGD-Targeted Biosynthetic Nanobubbles for Ultrasound Molecular Imaging of Osteosarcoma

Purpose

Osteosarcoma is the most common primary malignant tumor of the bone. However, there is a lack of effective means for early diagnosis due to the heterogeneity of tumors and the complexity of tumor microenvironment. αvβ3 integrin, a crucial role in the growth and spread of tumors, is not only an effective biomarker for cancer angiogenesis, but also highly expressed in many tumor cells. Here, we selected it as the imaging target and fabricated iRGD-sGVs acoustic probe for the early-stage diagnosis of osteosarcoma.

Materials and Methods

Biological nanoscale gas vesicles (sGVs) were extracted from Serratia 39006. Their morphology was analyzed with phase contrast and transmission electron microscopes. Particle size and zeta potential were measured by a Zetasizer. iRGD-targeted molecular probes (iRGD-sGVs) were prepared by coupling iRGD to sGVs via Mal-PEG2000-NHS. Targeting efficiency of iRGD-sGVs was evaluated using flow cytometry and confocal microscopy on endothelial and K7M2 osteosarcoma cells. In vivo contrast-enhanced ultrasound imaging of iRGD-sGVs was performed in osteosarcoma-bearing mice, and the expression of avβ3 in osteosarcoma was detected through immunofluorescence staining assay. Biocompatibility of sGVs was assessed by hemolysis tests, CCK8 cytotoxicity assays, blood biochemical tests, and HE staining.

Results

sGVs from Serratia.39006 have smaller particle size (about 160 nm). Our in vitro and in vivo experiments showed the specifically binding ability of iRGD-sGVs to both vascular endothelial cells and tumor cells, producing the stronger and longer acoustic signals in tumors in comparison with the control probe. Immunofluorescence staining results indicated iRGD-sGVs were co-localized with highly expressed αvβ3 in tumor vasculature and osteosarcoma cells. Biocompatibility analysis showed no significant cytotoxicity of iRGD-sGVs to mice.

Conclusion

Our study provides a new strategy for early diagnosis of osteosarcoma.

Fixation alters the physical properties of tumor tissue that regulate nanomedicine transport

To have the desired therapeutic effect, nanomedicines and macromolecular medications must move from the site of injection to the site of action, without having adverse effects. Transvascular transport is a critical step of this navigation, as exemplified by the Enhanced Permeability and Retention (EPR) effect in solid tumors, not found in normal organs. Numerous studies have concluded that passive, diffusion- and convection-based transport predominates over active, cellular mechanisms in this effect. However, recent work using a new approach reevaluated this principle by comparing tumors with or without fixation and concluded the opposite. Here, we address the controversy generated by this new approach by reporting evidence from experimental investigations and computer simulations that separate the contributions of active and passive transport. Our findings indicate that tissue fixation reduces passive transport as well as active transport, indicating the need for new methods to distinguish the relative contributions of passive and active transport.

Research Progress on Cyclic-Peptide Functionalized Nanoparticles for Tumor-Penetrating Delivery

A key challenge in cancer treatment is the effective delivery of drugs into deep regions of tumor tissues, which are impermeable due to abnormal vascular network, increased interstitial fluid pressure (IFP), abundant extra cellular matrix (ECM), and heterogeneity of tumor cells. Cyclic peptides have been used for the surface engineering of nanoparticles to enhance the tumor-penetrating efficacy of drugs. Compared with other surface ligands, cyclic peptides are more easily produced by automated chemical synthesis, and they are featured by their higher binding affinity with their targets, tumor selectivity, stability against degradation, and low toxicity. In this review, different types of cyclic peptides, their physicochemical properties and their in vivo pharmacokinetics are introduced. Next, the progress of cyclic peptide-functionalized drug delivery nanodevices is updated, and the mechanism underlying the tumor-penetrating properties of cyclic peptide-functionalized drug delivery nanodevices is discussed.

My scientific journey to and through extracellular matrix

This article recounts my journey as a scientist in the early days of extracellular matrix research through the discovery of fibronectin, the RGD sequence as a key recognition motif in fibronectin and other adhesion proteins, and isolation and cloning of integrins. I also discuss more recent work on identification of molecular "zip codes" by in vivo screening of peptide libraries expressed on phage, which led us right back to RGD and integrins. Many disease-specific zip codes have turned out to be based on altered expression of extracellular matrix molecules and integrins. Homing peptides and antibodies recognizing zip code molecules are being used in drug delivery applications, some of which have advanced into clinical trials.

A smart tablet-phone-based high-performance pancreatic cancer cell biosensing system for drug screening

Exploring more efficient pancreatic cancer drug screening platforms is of significant importance for accelerating the drug development process. In this study, we developed a high-sensitivity bioluminescence system based on smartphones and smart tablets, and constructed a pancreatic cancer drug screening platform (PCDSP) by combining the pancreatic cancer cell sensing model (PCCSM) on the multiwell plates (MTP). A smart tablet was used as the light source and a smartphone as the colorimetric sensing device. The smartphone dynamically controls the color and brightness displayed on the smart tablet to achieve lower LOD and wider detection ranges. We constructed PCCSM for 24 h, 48 h, and 72 h , and performed colorimetric experiments using both PCDSP and a commercial plate reader (CPR). The results showed that the PCDSP had a lower LOD than that of CPR. Moreover, PCDSP even exhibited a lower LOD for 24 h PCCSM testing compared to CPR for 48 h PCCSM testing, effectively shortening the drug evaluation process. Additionally, the PCDSP offers higher portability and efficiency compared with CPR, making it a promising platform for efficient pancreatic cancer drug screening.

Immunological properties of silica nanoparticles: a structure-activity relationship study

Silica nanoparticles are increasingly considered for drug delivery applications. These applications require an understanding of their biocompatibility, including their interactions with the immune system. However, systematic studies for silica nanoparticle immunological safety profiles are lacking. To fill this gap, we conducted an in vitro study investigating various aspects of silica nanoparticles' interactions with blood and immune cells. Four types of silica nanoparticles with variations in size and porosity were studied. These included nonporous Stöber silica nanoparticles with average diameters of approximately 50 and 100 nm (SNP50 and SNP100), mesoporous silica nanoparticles of approximately 100 nm (Meso100), and hollow mesoporous silica nanoparticles of approximately 100 nm (HMSNP100) in diameter, respectively. The hematological compatibility was assessed using hemolysis, complement activation, platelet aggregation, and plasma coagulation assays. The effects of nanoparticles on immune cell function were studied using in vitro phagocytosis, chemotaxis, natural killer cell cytotoxicity, leukocyte proliferation, human lymphocyte activation, colony-forming unit granulocyte-macrophage, and leukocyte procoagulant activity assays. The in vitro findings suggest that at high concentrations, corresponding to the in vivo human dose of 40 mg/kg, silica nanoparticles demonstrated an array of immunotoxic effects that depended on their physicochemical properties. However, all types of silica nanoparticles studied were not immunotoxic at concentrations corresponding to lower doses (≤ 8 mg/kg) comparable to that of nanocarriers in other nanomedicines currently used in the clinic. These findings are promising for using silica nanoparticles for the systemic delivery of bioactive and imaging agents.

Polyester nanoparticles delivering chemotherapeutics: Learning from the past and looking to the future to enhance their clinical impact in tumor therapy

Polymeric nanoparticles (NPs), specifically those comprised of biodegradable and biocompatible polyesters, have been heralded as a game-changing drug delivery platform. In fact, poly(α-hydroxy acids) such as polylactide (PLA), poly(lactide-co-glycolide) (PLGA), and poly(ε-caprolactone) (PCL) have been heavily researched in the past three decades as the material basis of polymeric NPs for drug delivery applications. As materials, these polymers have found success in resorbable sutures, biodegradable implants, and even monolithic, biodegradable platforms for sustained release of therapeutics (e.g., proteins and small molecules) and diagnostics. Few fields have gained more attention in drug delivery through polymeric NPs than cancer therapy. However, the clinical translational of polymeric nanomedicines for treating solid tumors has not been congruent with the fervor or funding in this particular field of research. Here, we attempt to provide a comprehensive snapshot of polyester NPs in the context of chemotherapeutic delivery. This includes a preliminary exploration of the polymeric nanomedicine in the cancer research space. We examine the various processes for producing polyester NPs, including methods for surface-functionalization, and related challenges. After a detailed overview of the multiple factors involved with the delivery of NPs to solid tumors, the crosstalk between particle design and interactions with biological systems is discussed. Finally, we report state-of-the-art approaches toward effective delivery of NPs to tumors, aiming at identifying new research areas and re-evaluating the reasons why some research avenues have underdelivered. We hope our effort will contribute to a better understanding of the gap to fill and delineate the future research work needed to bring polyester-based NPs closer to clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Intertumoral and intratumoral barriers as approaches for drug delivery and theranostics to solid tumors using stimuli-responsive materials

The solid tumors provide a series of biological barriers in cellular microenvironment for designing drug delivery methods based on advanced stimuli-responsive materials. These intertumoral and intratumoral barriers consist of perforated endotheliums, tumor cell crowding, vascularity, lymphatic drainage blocking effect, extracellular matrix (ECM) proteins, hypoxia, and acidosis. Triggering opportunities have been drawn for solid tumor therapies based on single and dual stimuli-responsive drug delivery systems (DDSs) that not only improved drug targeting in deeper sites of the tumor microenvironments, but also facilitated the antitumor drug release efficiency. Single and dual stimuli-responsive materials which are known for their lowest side effects can be categorized in 17 main groups which involve to internal and external stimuli anticancer drug carriers in proportion to microenvironments of targeted solid tumors. Development of such drug carriers can circumvent barriers in clinical trial studies based on their superior capabilities in penetrating into more inaccessible sites of the tumor tissues. In recent designs, key characteristics of these DDSs such as fast response to intracellular and extracellular factors, effective cytotoxicity with minimum side effect, efficient permeability, and rate and location of drug release have been discussed as core concerns of designing paradigms of these materials.

Tumour-specific activation of a tumour-blood transport improves the diagnostic accuracy of blood tumour markers in mice

BACKGROUND

The accuracy of blood-based early tumour recognition is compromised by signal production at non-tumoral sites, low amount of signal produced by small tumours, and variable tumour production. Here we examined whether tumour-specific enhancement of vascular permeability by the particular tumour homing peptide, iRGD, which carries dual function of binding to integrin receptors overexpressed in the tumour vasculature and is known to promote extravasation via neuropilin-1 receptor upon site-specific cleavage, might be useful to improve blood-based tumour detection by inducing a yet unrecognised vice versa tumour-to-blood transport.

METHODS

To detect an iRGD-induced tumour-to-blood transport, we examined the effect of intravenously injected iRGD on blood levels of α-fetoprotein (AFP) and autotaxin in several mouse models of hepatocellular carcinoma (HCC) or in mice with chronic liver injury without HCC, and on prostate-specific antigen (PSA) levels in mice with prostate cancer.

FINDINGS

Intravenously injected iRGD rapidly and robustly elevated the blood levels of AFP in several mouse models of HCC, but not in mice with chronic liver injury. The effect was primarily seen in mice with small tumours and normal basal blood AFP levels, was attenuated by an anti-neuropilin-1 antibody, and depended on the concentration gradient between tumour and blood. iRGD treatment was also able to increase blood levels of autotaxin in HCC mice, and of PSA in mice with prostate cancer.

INTERPRETATION

We conclude that iRGD induces a tumour-to-blood transport in a tumour-specific fashion that has potential of improving diagnosis of early stage cancer.

FUNDING

Deutsche Krebshilfe, DKTK, LOEWE-Frankfurt Cancer Institute.

Injectable hybrid hydrogels enable enhanced combination chemotherapy and roused anti-tumor immunity in the synergistic treatment of pancreatic ductal adenocarcinoma

Chemotherapy and immunotherapy have shown no significant outcome for unresectable pancreatic ductal adenocarcinoma (PDAC). Multi-drug combination therapy has become a consensus in clinical trials to explore how to arouse anti-tumor immunity and meanwhile overcome the poorly tumoricidal effect and the stroma barrier that greatly hinders drug penetration. To address this challenge, a comprehensive strategy is proposed to fully utilize both the ferroptotic vulnerability of PDAC to potently irritate anti-tumor immunity and the desmoplasia-associated focal adhesion kinase (FAK) to wholly improve the immunosuppressive microenvironment via sustained release of drugs in an injectable hydrogel for increasing drug penetration in tumor location and averting systematic toxicity. The injectable hydrogel ED-M@CS/MC is hybridized with micelles loaded with erastin that exclusively induces ferroptosis and a FAK inhibitor defactinib for inhibiting stroma formation, and achieves sustained release of the drugs for up to 12 days. With only a single intratumoral injection, the combination treatment with erastin and defactinib produces further anti-tumor performance both in xenograft and KrasG12D-engineered primary PDAC mice and synergistically promotes the infiltration of CD8+ cytotoxic T cells and the reduction of type II macrophages. The findings may provide a novel promising strategy for the clinical treatment of PDAC.

Tumor-penetrating iRGD facilitates penetration of poly(floxuridine-ketal)-based nanomedicine for enhanced pancreatic cancer therapy

Efficient intratumoral penetration is essential for nanomedicine to eradicate pancreatic tumors. Although nanomedicine can enter the perivascular space of pancreatic tumors, their access to distal tumor cells, aloof from the vessels, remains a formidable challenge. Here, we synthesized an acid-activatable macromolecular prodrug of floxuridine (FUDR)-poly(FUDR-ketal), engineered a micellar nanomedicine of FUDR, and intravenously co-administered the nanomedicine with the tumor-penetrating peptide iRGD for enhanced treatment of pancreatic tumor. A FUDR-derived mono-isopropenyl ether was synthesized and underwent self-addition polymerization to afford the hydrophobic poly(FUDR-ketal), which was subsequently co-assembled with amphiphilic DSPE-mPEG into the micellar nanomedicine with size of 12 nm and drug content of 56.8 wt% using nanoprecipitation technique. The acetone-based ketal-linked poly(FUDR-ketal) was triggered by acid to release FUDR to inhibit cell proliferation. In an orthotopic pancreatic tumor model derived from KPC (KrasLSL-G12D/+; Trp53LSL-R172H/+; Pdx1-Cre) cells that overexpress neuropilin-1 (NRP-1) receptor, iRGD improved penetration of FUDR nanomedicine into tumor parenchyma and potentiated the therapeutic efficacy. Our nanoplatform, along with iRGD, thus appears to be promising for efficient penetration and activation of acid-responsive nanomedicines for enhanced pancreatic cancer therapy.

An exosomal strategy for targeting cancer-associated fibroblasts mediated tumors desmoplastic microenvironments

Tumors desmoplastic microenvironments are characterized by abundant stromal cells and extracellular matrix (ECM) deposition. Cancer-associated fibroblasts (CAFs), as the most abundant of all stromal cells, play significant role in mediating microenvironments, which not only remodel ECM to establish unique pathological barriers to hinder drug delivery in desmoplastic tumors, but also talk with immune cells and cancer cells to promote immunosuppression and cancer stem cells-mediated drug resistance. Thus, CAFs mediated desmoplastic microenvironments will be emerging as promising strategy to treat desmoplastic tumors. However, due to the complexity of microenvironments and the heterogeneity of CAFs in such tumors, an effective deliver system should be fully considered when designing the strategy of targeting CAFs mediated microenvironments. Engineered exosomes own powerful intercellular communication, cargoes delivery, penetration and targeted property of desired sites, which endow them with powerful theranostic potential in desmoplastic tumors. Here, we illustrate the significance of CAFs in tumors desmoplastic microenvironments and the theranostic potential of engineered exosomes targeting CAFs mediated desmoplastic microenvironments in next generation personalized nano-drugs development.

Biomimetic nanotechnology for cancer immunotherapy: State of the art and future perspective

Cancer continues to be a significant worldwide cause of mortality. This underscores the urgent need for novel strategies to complement and overcome the limitations of conventional therapies, such as imprecise targeting and drug resistance. Cancer Immunotherapy utilizes the body's immune system to target malignant cells, reducing harm to healthy tissue. Nevertheless, the efficacy of immunotherapy exhibits variation across individuals and has the potential to induce autoimmune responses. Biomimetic nanoparticles (bNPs) have transformative potential in cancer immunotherapy, promising improved accurate targeting, immune system activation, and resistance mechanisms, while also reducing the occurrence of systemic autoimmune side effects. This integration offers opportunities for personalized medicine and better therapeutic outcomes. Despite considerable potential, bNPs face barriers like insufficient targeting, restricted biological stability, and interactions within the tumor microenvironment. The resolution of these concerns is crucial in order to expedite the integration of bNPs from the research setting into clinical therapeutic uses. In addition, optimizing manufacturing processes and reducing bNP-related costs are essential for practical implementation. The present research introduces comprehensive classifications of bNPs as well as recent achievements in their application in cancer immunotherapies, emphasizing the need to address barriers for swift clinical integration.

Nanocarriers address intracellular barriers for efficient drug delivery, overcoming drug resistance, subcellular targeting and controlled release

The cellular barriers are major bottlenecks for bioactive compounds entering into cells to accomplish their biological functions, which limits their biomedical applications. Nanocarriers have demonstrated high potential and benefits for encapsulating bioactive compounds and efficiently delivering them into target cells by overcoming a cascade of intracellular barriers to achieve desirable therapeutic and diagnostic effects. In this review, we introduce the cellular barriers ahead of drug delivery and nanocarriers, as well as summarize recent advances and strategies of nanocarriers for increasing internalization with cells, promoting intracellular trafficking, overcoming drug resistance, targeting subcellular locations and controlled drug release. Lastly, the future perspectives of nanocarriers for intracellular drug delivery are discussed, which mainly focus on potential challenges and future directions. Our review presents an overview of intracellular drug delivery by nanocarriers, which may encourage the future development of nanocarriers for efficient and precision drug delivery into a wide range of cells and subcellular targets.

Revealing neuropilin expression patterns in pancreatic cancer: From single‑cell to therapeutic opportunities (Review)

Pancreatic cancer, one of the most fatal types of human cancers, includes several non-epithelial and stromal components, such as activated fibroblasts, vascular cells, neural cells and immune cells, that are involved in different cancers. Vascular endothelial cell growth factor 165 receptors 1 [neuropilin-1 (NRP-1)] and 2 (NRP-2) play a role in the biological behaviors of pancreatic cancer and may appear as potential therapeutic targets. The NRP family of proteins serve as co-receptors for vascular endothelial growth factor, transforming growth factor β, hepatocyte growth factor, fibroblast growth factor, semaphorin 3, epidermal growth factor, insulin-like growth factor and platelet-derived growth factor. Investigations of mechanisms that involve the NRP family of proteins may help develop novel approaches for overcoming therapy resistance in pancreatic cancer. The present review aimed to provide an in-depth exploration of the multifaceted roles of the NRP family of proteins in pancreatic cancer, including recent findings from single-cell analysis conducted within the context of pancreatic adenocarcinoma, which revealed the intricate involvement of NRP proteins at the cellular level. Through these efforts, the present study endeavored to further reveal their relationships with different biological processes and their potential as therapeutic targets in various treatment modalities, offering novel perspectives and directions for the treatment of pancreatic cancer.

Tumor-homing peptide iRGD-conjugate enhances tumor accumulation of camptothecin for colon cancer therapy

Poor intracellular uptake of therapeutics in the tumor parenchyma is a key issue in cancer therapy. We describe a novel approach to enhance tumor targeting and achieve targeted delivery of camptothecin (CPT) based on a tumor-homing internalizing RGD peptide (iRGD). We synthesized an iRGD-camptothecin conjugate (iRGD-CPT) covalently coupled by a heterobifunctional linker and evaluated its in vitro and in vivo activity in human colon cancer cells. In vitro studies revealed that iRGD-CPT penetrated cells efficiently and reduced colon cancer cell viability to a significantly greater extent at micromolar concentrations than did the parent drug. Furthermore, iRGD-CPT showed high distribution toward tumor tissue, effectively suppressed tumor progression, and showed enhanced antitumor effects relative to the parent drug in a mouse model, demonstrating that iRGD-CPT is effective in vivo cancer treatment. These results suggest that intracellular delivery of CPT via the iRGD peptide is a promising drug delivery strategy that will facilitate the development of CPT derivatives and prodrugs with improved efficacy.

Reprogramming the pancreatic cancer stroma and immune landscape by a silicasome nanocarrier delivering nintedanib, a protein tyrosine kinase inhibitor

The prevailing desmoplastic stroma and immunosuppressive microenvironment within pancreatic ductal adenocarcinoma (PDAC) pose substantial challenges to therapeutic intervention. Despite the potential of protein tyrosine kinase (PTK) inhibitors in mitigating the desmoplastic stromal response and enhancing the immune milieu, their efficacy is curtailed by suboptimal pharmacokinetics (PK) and insufficient tumor penetration. To surmount these hurdles, we have pioneered a novel strategy, employing lipid bilayer-coated mesoporous silica nanoparticles (termed "silicasomes") as a carrier for the delivery of Nintedanib. Nintedanib, a triple PTK inhibitor that targets vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor receptors, was encapsulated in the pores of silicasomes via a remote loading mechanism for weak bases. This innovative approach not only enhanced pharmacokinetics and intratumor drug concentrations but also orchestrated a transformative shift in the desmoplastic and immune landscape in a robust orthotopic KRAS-mediated pancreatic carcinoma (KPC) model. Our results demonstrate attenuation of vascular density and collagen content through encapsulated Nintedanib treatment, concomitant with significant augmentation of the CD8+/FoxP3+ T-cell ratio. This remodeling was notably correlated with tumor regression in the KPC model. Strikingly, the synergy between encapsulated Nintedanib and anti-PD-1 immunotherapy further potentiated the antitumor effect. Both free and encapsulated Nintedanib induced a transcriptional upregulation of PD-L1 via the extracellular signal-regulated kinase (ERK) pathway. In summary, our pioneering approach involving the silicasome carrier not only improved antitumor angiogenesis but also profoundly reshaped the desmoplastic stromal and immune landscape within PDAC. These insights hold excellent promise for the development of innovative combinatorial strategies in PDAC therapy.

Enhanced Tumor Targeting and Penetration of Proteolysis-Targeting Chimeras through iRGD Peptide Conjugation: A Strategy for Precise Protein Degradation in Breast Cancer

Proteolysis-targeting chimeras (PROTACs) have recently emerged as a promising technology for drug development. However, poor water solubility, limited tissue selectivity, and inadequate tumor penetration pose significant challenges for PROTAC-based therapies in cancer treatment. Herein, we developed an iRGD-PROTAC conjugation strategy utilizing tumor-penetrating cyclic peptide iRGD (CRGDK/RGPD/EC) to deliver PROTACs deep into breast cancer tissues. As a conceptual validation study, iRGD peptides were conjugated with a bromodomain-containing protein 4 (BRD4) PROTAC through a GSH-responsive linker. The resulting iRGD-PROTAC conjugate iPR showed enhanced water solubility, tumor-targeting capability, and penetration within tumor tissues, resulting in increased antibreast cancer efficacy in animal models and patient-derived organoids. This study demonstrates the advantages of combining iRGD and PROTACs in improving drug delivery and highlights the importance of tissue selectivity and penetration ability in PROTAC-based therapeutics.

Combination of irinotecan silicasome nanoparticles with radiation therapy sensitizes immunotherapy by modulating the activation of the cGAS/STING pathway for colorectal cancer

Our previous clinical trial (Identifier: NCT02605265) revealed that addition of irinotecan (IRIN) to neoadjuvant chemoradiotherapy for rectal cancer could improve the curative effect. However, the adverse effects caused by IRIN limited the wide application of IRIN chemoradiotherapy. This study aimed to explore the mechanism under the synergistic effects of IRIN plus radiation therapy in colorectal cancer (CRC) cells and optimization of IRIN delivery via a silicasome nanocarrier in vivo. Our results revealed that compared with single IRIN or radiation treatment, IRIN combined with radiation therapy remarkably activated the intracellular cGAS/STING pathway, and promoted the expression levels of major histocompatibility complex class I (MHC-I) and programmed death ligand 1 (PD-L1). Further, a silicasome (mesoporous silica nanoparticle coated with lipid bilayer) nanocarrier was utilized to improve the delivery of IRIN with enhanced efficacy and reduced side effects. In the MC38 CRC syngeneic tumor model, IRIN silicasome combined with radiation therapy demonstrated a greater antitumor efficacy than free IRIN plus radiation therapy. Flow cytometry showed the increased number of CD4+ T cells, CD8+ T cells, and dendritic cells (DCs) in tumor in the IRIN silicasome plus radiation group. The immunofluorescence staining further confirmed the activated immune microenvironment with the elevated interferon-γ (IFN-γ) deposition. Besides, the antitumor effect of IRIN silicasome plus radiation therapy was synergistically enhanced by anti-PD-1 immunotherapy. These findings indicated that the combination of IRIN silicasome with radiation therapy could sensitize immunotherapy by manipulating the cGAS/STING pathway serving as a new strategy for CRC treatment.

Mind the (guidance) signals! Translational relevance of semaphorins, plexins, and neuropilins in pancreatic cancer

Pancreatic cancer is a major cause of demise worldwide. Although key associated genetic changes have been discovered, disease progression is sustained by pathogenic mechanisms that are poorly understood at the molecular level. In particular, the tissue microenvironment of pancreatic adenocarcinoma (PDAC) is usually characterized by high stromal content, scarce recruitment of immune cells, and the presence of neuronal fibers. Semaphorins and their receptors, plexins and neuropilins, comprise a wide family of regulatory signals that control neurons, endothelial and immune cells, embryo development, and normal tissue homeostasis, as well as the microenvironment of human tumors. We focus on the role of these molecular signals in pancreatic cancer progression, as revealed by experimental research and clinical studies, including novel approaches for cancer treatment.

Tumor Abnormality-Oriented Nanomedicine Design

Anticancer nanomedicines have been proven effective in mitigating the side effects of chemotherapeutic drugs. However, challenges remain in augmenting their therapeutic efficacy. Nanomedicines responsive to the pathological abnormalities in the tumor microenvironment (TME) are expected to overcome the biological limitations of conventional nanomedicines, enhance the therapeutic efficacies, and further reduce the side effects. This Review aims to quantitate the various pathological abnormalities in the TME, which may serve as unique endogenous stimuli for the design of stimuli-responsive nanomedicines, and to provide a broad and objective perspective on the current understanding of stimuli-responsive nanomedicines for cancer treatment. We dissect the typical transport process and barriers of cancer drug delivery, highlight the key design principles of stimuli-responsive nanomedicines designed to tackle the series of barriers in the typical drug delivery process, and discuss the "all-into-one" and "one-for-all" strategies for integrating the needed properties for nanomedicines. Ultimately, we provide insight into the challenges and future perspectives toward the clinical translation of stimuli-responsive nanomedicines.

Extracellular Vesicles Facilitate the Transportation of Nanoparticles within and between Cells for Enhanced Tumor Therapy

The interaction between nanoparticles and cells is closely associated with the therapeutic effects of nanomedicine. Nanoparticles could be transported among cells, but the process-related mechanism remains to be further explored. In this study, it was found that endocytosed cationic polymer nanoparticles (cNPs) could be excreted in an extracellular vesicle (EV)-coated form (cNP@EVs). It was deduced that cNPs may pass through early endosomes, multivesicular bodies (MVBs), and autophagic MVBs within cells. Moreover, a high level of autophagy facilitated the exocytosis process. Since EVs were the effective vehicles for conveying biological information and substances, cNP@EVs were proved to be efficient forms for the intercellular transportation of nanoparticles and have the potential as efficient biomimetic drug delivery systems. These properties endowed cNP@EVs with deep penetration and enhanced antitumor activity. Our findings provided a proof-of-concept for understanding the transfer process of nanoparticles among cells and may help us to further utilize EV-mediated transportation of nanoparticles, therefore, expanding its clinical application.

The Efficacy of Nanoparticle Delivery to Hypoxic Solid Tumors by ciRGD Co-Administration Depends on Neuropilin-1 and Neutrophil Levels

The ability to improve nanoparticle delivery to solid tumors is an actively studied domain, where various mechanisms are looked into. In previous work, the authors have looked into nanoparticle size, tumor vessel normalization, and disintegration, and here it is aimed to continue this work by performing an in-depth mechanistic study on the use of ciRGD peptide co-administration. Using a multiparametric approach, it is observed that ciRGD can improve nanoparticle delivery to the tumor itself, but also to tumor cells specifically better than vessel normalization strategies. The effect depends on the level of tumor perfusion, hypoxia, neutrophil levels, and vessel permeability. This work shows that upon characterizing tumors for these parameters, conditions can be selected that can optimally benefit from ciRGD co-administration as a means to improve NP delivery to solid tumors.

Nanoparticles systemically biodistribute to regenerating skeletal muscle in DMD

Skeletal muscle disease severity can often progress asymmetrically across muscle groups and heterogeneously within tissues. An example is Duchenne Muscular Dystrophy (DMD) in which lack of dystrophin results in devastating skeletal muscle wasting in some muscles whereas others are spared or undergo hypertrophy. An efficient, non-invasive approach to identify sites of asymmetry and degenerative lesions could enable better patient monitoring and therapeutic targeting of disease. In this study, we utilized a versatile intravenously injectable mesoporous silica nanoparticle (MSNP) based nanocarrier system to explore mechanisms of biodistribution in skeletal muscle of mdx mouse models of DMD including wildtype, dystrophic, and severely dystrophic mice. Moreover, MSNPs could be imaged in live mice and whole muscle tissues enabling investigation of how biodistribution is altered by different types of muscle pathology such as inflammation or fibrosis. We found MSNPs were tenfold more likely to aggregate within select mdx muscles relative to wild type, such as gastrocnemius and quadriceps. This was accompanied by decreased biodistribution in off-target organs. We found the greatest factor affecting preferential delivery was the regenerative state of the dystrophic skeletal muscle with the highest MSNP abundance coinciding with the regions showing the highest level of embryonic myosin staining and intramuscular macrophage uptake. To demonstrate, muscle regeneration regulated MSNP distribution, we experimentally induced regeneration using barium chloride which resulted in a threefold increase of intravenously injected MSNPs to sites of regeneration 7 days after injury. These discoveries provide the first evidence that nanoparticles have selective biodistribution to skeletal muscle in DMD to areas of active regeneration and that nanoparticles could enable diagnostic and selective drug delivery in DMD skeletal muscle.

Nanomedicine in cancer therapy

Cancer remains a highly lethal disease in the world. Currently, either conventional cancer therapies or modern immunotherapies are non-tumor-targeted therapeutic approaches that cannot accurately distinguish malignant cells from healthy ones, giving rise to multiple undesired side effects. Recent advances in nanotechnology, accompanied by our growing understanding of cancer biology and nano-bio interactions, have led to the development of a series of nanocarriers, which aim to improve the therapeutic efficacy while reducing off-target toxicity of the encapsulated anticancer agents through tumor tissue-, cell-, or organelle-specific targeting. However, the vast majority of nanocarriers do not possess hierarchical targeting capability, and their therapeutic indices are often compromised by either poor tumor accumulation, inefficient cellular internalization, or inaccurate subcellular localization. This Review outlines current and prospective strategies in the design of tumor tissue-, cell-, and organelle-targeted cancer nanomedicines, and highlights the latest progress in hierarchical targeting technologies that can dynamically integrate these three different stages of static tumor targeting to maximize therapeutic outcomes. Finally, we briefly discuss the current challenges and future opportunities for the clinical translation of cancer nanomedicines.

iRGD-targeted Physalis Mottle Virus-like Nanoparticles for Targeted Cancer Delivery

Nanomedicine provides a promising platform for the molecular treatment of disease. An ongoing challenge in nanomedicine is the targeted delivery of intravenously administered nanoparticles to particular tissues, which is of special interest in cancer. In this study, we show that the conjugation of iRGD peptides, which specifically target tumor neovasculature, to the surface of Physalis mottle virus (PhMV)-like nanoparticles leads to rapid cellular uptake in vitro and tumor homing in vivo. We then show that iRGD-targeted PhMV loaded with the chemotherapeutic doxorubicin shows increased potency in a murine flank xenograft model of cancer. Our results validate that PhMV-like nanoparticles can be targeted to tumors through iRGD-peptide conjugation and suggest that iRGD-PhMV provides a promising platform for the targeted delivery of molecular cargo to tumors.

Multifunctional nanostructures: Intelligent design to overcome biological barriers

Over the past three decades, nanoscience has offered a unique solution for reducing the systemic toxicity of chemotherapy drugs and for increasing drug therapeutic efficiency. However, the poor accumulation and pharmacokinetics of nanoparticles are some of the key reasons for their slow translation into the clinic. The is intimately linked to the non-biological nature of nanoparticles and the aberrant features of solid cancer, which together significantly compromise nanoparticle delivery. New findings on the unique properties of tumors and their interactions with nanoparticles and the human body suggest that, contrary to what was long-believed, tumor features may be more mirage than miracle, as the enhanced permeability and retention based efficacy is estimated to be as low as 1%. In this review, we highlight the current barriers and available solutions to pave the way for approved nanoformulations. Furthermore, we aim to discuss the main solutions to solve inefficient drug delivery with the use of nanobioengineering of nanocarriers and the tumor environment. Finally, we will discuss the suggested strategies to overcome two or more biological barriers with one nanocarrier. The variety of design formats, applications and implications of each of these methods will also be evaluated.

Exploration of tumor penetrating peptide iRGD as a potential strategy to enhance tumor penetration of cancer nanotherapeutics

Cancer therapy continues to be a huge challenge as most chemotherapeutic agents exert serious adverse effects on healthy organs. Chemotherapeutic agents lack selective targeting and even the existing target specific therapies are failing due to poor distribution into the tumor microenvironment. Nanotechnology offers multiple advantages to address the limitations encountered by conventional therapy. However, the delivery of nanotherapeutics to tumor tissue has not improved over the years partly due to the poor and inadequate distribution of nanotherapeutics into deeper tumor regions resulting in resistance and relapse. To curb the penetration concerns, iRGD was explored and found to be highly effective in improving the delivery of cancer nanomedicine. The preclinical observations are highly encouraging; however, the clinical translation is at a nascent stage. Based on this, we have made an elaborative effort to give a detailed account of various promising applications of iRGD to increase anticancer and tumor imaging potential. Importantly, we have comprehensively discussed the shortcomings and uncertainties associated with the clinical translation of iRGD-based therapeutic approaches and future directions.

Engineered Design of a Mesoporous Silica Nanoparticle-Based Nanocarrier for Efficient mRNA Delivery in Vivo

We have developed tailor-designed mesoporous silica nanoparticles (MSNPs) specifically for delivering mRNA. Our unique assembly protocol involves premixing mRNA with a cationic polymer and then electrostatically binding it to the MSNP surface. Since the key physicochemical parameters of MSNPs could influence the biological outcome, we also investigated the roles of size, porosity, surface topology, and aspect ratio on the mRNA delivery. These efforts allow us to identify the best-performing carrier, which was able to achieve efficient cellular uptake and intracellular escape while delivering a luciferase mRNA in mice. The optimized carrier remained stable and active for at least 7 days after being stored at 4 °C and was able to enable tissue-specific mRNA expression, particularly in the pancreas and mesentery after intraperitoneal injection. The optimized carrier was further manufactured in a larger batch size and found to be equally efficient in delivering mRNA in mice and rats, without any obvious toxicity.

Assessment of the Pharmacokinetics, Disposition, and Duration of Action of the Tumour-Targeting Peptide CEND-1

CEND-1 (iRGD) is a bifunctional cyclic peptide that can modulate the solid tumour microenvironment, enhancing the delivery and therapeutic index of co-administered anti-cancer agents. This study explored CEND-1's pharmacokinetic (PK) properties pre-clinically and clinically, and assessed CEND-1 distribution, tumour selectivity and duration of action in pre-clinical tumour models. Its PK properties were assessed after intravenous infusion of CEND-1 at various doses in animals (mice, rats, dogs and monkeys) and patients with metastatic pancreatic cancer. To assess tissue disposition, [3H]-CEND-1 radioligand was administered intravenously to mice bearing orthotopic 4T1 mammary carcinoma, followed by tissue measurement using quantitative whole-body autoradiography or quantitative radioactivity analysis. The duration of the tumour-penetrating effect of CEND-1 was evaluated by assessing tumour accumulation of Evans blue and gadolinium-based contrast agents in hepatocellular carcinoma (HCC) mouse models. The plasma half-life was approximately 25 min in mice and 2 h in patients following intravenous administration of CEND-1. [3H]-CEND-1 localised to the tumour and several healthy tissues shortly after administration but was cleared from most healthy tissues by 3 h. Despite the rapid systemic clearance, tumours retained significant [3H]-CEND-1 several hours post-administration. In mice with HCC, the tumour penetration activity remained elevated for at least 24 h after the injection of a single dose of CEND-1. These results indicate a favourable in vivo PK profile of CEND-1 and a specific and sustained tumour homing and tumour penetrability. Taken together, these data suggest that even single injections of CEND-1 may elicit long-lasting tumour PK improvements for co-administered anti-cancer agents.

Nanoparticles of VAV1 siRNA combined with LL37 peptide for the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer-related death, and it is highly resistant to therapy owing to its unique extracellular matrix. VAV1 protein, overexpressed in several cancer diseases including pancreatic cancer (PC), increases tumor proliferation and enhances metastases formation, which are associated with decreased survival. We hypothesized that an additive anti-tumor effect could be obtained by co-encapsulating in PLGA nanoparticles (NPs), the negatively charged siRNA against VAV1 (siVAV1) with the positively charged anti-tumor LL37 peptide, as a counter-ion. Several types of NPs were formulated and were characterized for their physicochemical properties, cellular internalization, and bioactivity in vitro. NPs' biodistribution, toxicity, and bioactivity were examined in a mice PDAC model. An optimal siVAV1 formulation (siVAV1-LL37 NPs) was characterized with desirable physicochemical properties in terms of nano-size, low polydispersity index (PDI), neutral surface charge, high siVAV1 encapsulation efficiency, spherical shape, and long-term shelf-life stability. Cell assays demonstrated rapid engulfment by PC cells, a specific and significant dose-dependent proliferation inhibition, as well as knockdown of VAV1 mRNA levels and migration inhibition in VAV1⁺ cells. Treatment with siVAV1-LL37 NPs in the mice PDAC model revealed marked accumulation of NPs in the liver and in the tumor, resulting in an increased survival rate following suppression of tumor growth and metastases, mediated via the knockdown of both VAV1 mRNA and protein levels. This proof-of-concept study validates our hypothesis of an additive effect in the treatment of PC facilitated by co-encapsulating siVAV1 in NPs with LL37 serving a dual role as a counter ion as well as an anti-tumor agent.

Recent Advances in Well-Designed Therapeutic Nanosystems for the Pancreatic Ductal Adenocarcinoma Treatment Dilemma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with an extremely poor prognosis and low survival rate. Due to its inconspicuous symptoms, PDAC is difficult to diagnose early. Most patients are diagnosed in the middle and late stages, losing the opportunity for surgery. Chemotherapy is the main treatment in clinical practice and improves the survival of patients to some extent. However, the improved prognosis is associated with higher side effects, and the overall prognosis is far from satisfactory. In addition to resistance to chemotherapy, PDAC is significantly resistant to targeted therapy and immunotherapy. The failure of multiple treatment modalities indicates great dilemmas in treating PDAC, including high molecular heterogeneity, high drug resistance, an immunosuppressive microenvironment, and a dense matrix. Nanomedicine shows great potential to overcome the therapeutic barriers of PDAC. Through the careful design and rational modification of nanomaterials, multifunctional intelligent nanosystems can be obtained. These nanosystems can adapt to the environment's needs and compensate for conventional treatments' shortcomings. This review is focused on recent advances in the use of well-designed nanosystems in different therapeutic modalities to overcome the PDAC treatment dilemma, including a variety of novel therapeutic modalities. Finally, these nanosystems' bottlenecks in treating PDAC and the prospect of future clinical translation are briefly discussed.

Liposome-based diagnostic and therapeutic applications for pancreatic cancer

Pancreatic cancer is one of the harshest and most challenging cancers to treat, often labeled as incurable. Chemotherapy continues to be the most popular treatment yet yields a very poor prognosis. The main barriers such as inefficient drug penetration and drug resistance, have led to the development of drug carrier systems. The benefits, ease of fabrication and modification of liposomes render them as ideal future drug delivery systems. This review delves into the versatility of liposomes to achieve various mechanisms of treatment for pancreatic cancer. Not only are there benefits of loading chemotherapy drugs and targeting agents onto liposomes, as well as mRNA combined therapy, but liposomes have also been exploited for immunotherapy and can be programmed to respond to photothermal therapy. Multifunctional liposomal formulations have demonstrated significant pre-clinical success. Functionalising drug-encapsulated liposomes has resulted in triggered drug release, specific targeting, and remodeling of the tumor environment. Suppressing tumor progression has been achieved, due to their ability to more efficiently and precisely deliver chemotherapy. Currently, no multifunctional surface-modified liposomes are clinically approved for pancreatic cancer thus we aim to shed light on the trials and tribulations and progress so far, with the hope for liposomal therapy in the future and improved patient outcomes. STATEMENT OF SIGNIFICANCE: Considering that conventional treatments for pancreatic cancer are highly associated with sub-optimal performance and systemic toxicity, the development of novel therapeutic strategies holds outmost relevance for pancreatic cancer management. Liposomes are being increasingly considered as promising nanocarriers for providing not only an early diagnosis but also effective, highly specific, and safer treatment, improving overall patient outcome. This manuscript is the first in the last 10 years that revises the advances in the application of liposome-based formulations in bioimaging, chemotherapy, phototherapy, immunotherapy, combination therapies, and emergent therapies for pancreatic cancer management. Prospective insights are provided regarding several advantages resulting from the use of liposome technology in precision strategies, fostering new ideas for next-generation diagnosis and targeted therapies of pancreatic cancer.

Identification of an ALK-2 inhibitor as an agonist for intercellular exchange and tumor delivery of nanomaterial

Inefficient extravasation and penetration in solid tissues hinder the clinical outcome of nanoparticles (NPs). Recent studies have shown that the extravasation and penetration of NPs in solid tumor was mostly achieved via an active transcellular route. For this transport process, numerous efforts have been devoted to elucidate the endocytosis and subcellular trafficking of NPs. However, how they exit from one cell and re-enter into neighboring ones (termed intercellular exchange) remains poorly understood. We previously developed cellular assays that exclusively quantify the intercellular exchange of NPs in vitro. Our study showed that a significant portion of NPs are transferred inside extracellular vesicles (EVs). Pharmacological inhibition of EV biogenesis significantly reduced the tumor accumulation and vascular penetration of both inorganic and organic NPs in vivo. Intrigued by this result, we performed here a manual chemical screen with our assay, which identified that LDN-214117 (an inhibitor for activin receptor-like kinase-2, ALK-2) is an agonist of NP intercellular exchange. We further showed that LDN-214117 regulates the intercellular exchange by increasing the EV biogenesis. Mechanistic investigation showed that LDN-214117 functions via BMP (bone morphogenetic protein)-MAPK (mitogen-activated protein kinase) signaling pathway to increase EV biogenesis. We further demonstrated that LDN-214117 treatment in vivo enhanced the tumor accumulation and vascular penetration of a variety of NPs in multiple tumor models, which improves their antitumor efficacy. Overall, we showcase here the identification of a novel chemical compound with our intercellular exchange assays to modulate EV biogenesis and EV-mediated transport, thus boosting up the delivery and therapeutic efficacy of nanomaterial.

Advances in nanomaterial-based targeted drug delivery systems

Nanomaterial-based drug delivery systems (NBDDS) are widely used to improve the safety and therapeutic efficacy of encapsulated drugs due to their unique physicochemical and biological properties. By combining therapeutic drugs with nanoparticles using rational targeting pathways, nano-targeted delivery systems were created to overcome the main drawbacks of conventional drug treatment, including insufficient stability and solubility, lack of transmembrane transport, short circulation time, and undesirable toxic effects. Herein, we reviewed the recent developments in different targeting design strategies and therapeutic approaches employing various nanomaterial-based systems. We also discussed the challenges and perspectives of smart systems in precisely targeting different intravascular and extravascular diseases.

Overcoming pancreatic cancer immune resistance by codelivery of CCR2 antagonist using a STING-activating gemcitabine-based nanocarrier

STING agonist has recently gained much attention for cancer treatment, but the therapeutic potential of STING agonist is hampered by STING-associated tumor immune resistance. In this work, guided by both bioinformatics and computer modeling, we rationally designed a "one stone hits two birds" nanoparticle-based strategy to simultaneously activate STING innate immune response while eliminating STING-associated immune resistance for the treatment of pancreatic ductal adenocarcinoma (PDAC). We discovered that the ultra-small sized micellar system based on gemcitabine-conjugated polymer (PGEM), which showed superior capacity of penetration in pancreatic tumor spheroid model and orthotopic tumor model, could serve as a novel "STING agonist". The activation of STING signaling in dendritic cells (DCs) by PGEM increased both innate nature killer (NK) and adaptive anti-tumor T cell response. However, activation of STING signaling by PGEM in tumor cells also drove the induction of chemokines CCL2 and CCL7, resulting in immune resistance by recruiting tumor associated macrophage (TAM) and myeloid-derived suppressor cells (MDSCs). Through the combination of computer modeling and experimental screening, we developed a dual delivery modality by incorporating a CCR2 (the receptor shared by both CCL2 and CCL7) antagonist PF-6309 (PF) into PGEM micellar system. Our studies demonstrated that PGEM/PF formulation significantly reduced pancreatic tumor burden and induced potent anti-tumor immunity through reversing the CCL2/CCL7-mediated immunosuppression. Moreover, PGEM/PF sensitized PDAC tumors to anti-PD-1 therapy, leading to complete suppression/eradication of the tumors. Our work has shed light to the multi-faceted role of STING activation and provided a novel immunotherapy regimen to maximize the benefit of STING activation for PDAC treatment. In addition, this work paved a new way for bioinformatics and computer modeling-guided rational design of nanomedicine.

Ultrasound Molecular Imaging of Neovascularization for Evaluation of Endometrial Receptivity Using Magnetic iRGD-Modified Lipid-Polymer Hybrid Microbubbles

BACKGROUND

Angiogenesis plays an important role in endometrial receptivity, determining the response of the endometrium to the blastocyst at the early stage of embryo implantation. During the application of assisted reproduction technologies, it is very important to evaluate the status of uterine angiogenesis before deciding on embryo implantation. Targeted microbubbles (MBs)-based ultrasound molecular imaging (UMI) can noninvasively detect the expression status of biomarkers at the molecular level, thereby being a potential diagnosis strategy for various diseases and their therapeutic evaluation.

METHODS

The iRGD-lipopeptide (DSPE-PEG2000-iRGD) conjugate was prepared with iRGD peptides and DSPE-PEG2000-maleimide through the Michael-type addition reaction. Then, the magnetic iRGD-modified lipid-polymer hybrid MBs (Mag-iLPMs) were prepared with the double-emulsification-solvent-evaporation method. Magnetic targeting of Mag-iLPMs was confirmed under the microscope, followed by a rectangular magnet. Next, the in vitro targeted binding of MBs to murine brain-derived endothelial cells.3 (bEnd.3) and human umbilical vein endothelial cells (HUVEC) were evaluated. The ratio of MBs binding to bEnd.3 and HUVEC at the same field was also compared. For in vivo studies, bolus injections of targeted or control MBs were randomly administrated to non-pregnant or pregnant rats on day 5. Then, the uteri were imaged using a VisualSonics Vevo 2100 ultrasound system (Fujifilm VisualSonics Inc., Ontario, Canada) equipped with a high-frequency transducer. Ultrasonic imaging signals were acquired from Mag-iLPMs, and compared with Mag-LPMs, iLPMs, and LPMs.

RESULTS

The Mag-iLPMs showed excellent performance in ultrasound contrast imaging and binding affinity to target cells. Using the magnetic field, 10.5- and 12.47-fold higher binding efficiency to bEnd.3 and HUVEC were achieved compared to non-magnetic iLPMs, respectively. Significantly enhanced UMI signals were also observed in the uteri of rats intravenously injected pregnant rats (6.58-fold higher than rats injected with iLPMs).

CONCLUSION

We provided a powerful ultrasonic molecular functional imaging tool for uterine angiogenesis evaluation before embryonic implantation.

Nano-drug delivery system for pancreatic cancer: A visualization and bibliometric analysis

Background: Nano drug delivery system (NDDS) can significantly improve the delivery and efficacy of drugs against pancreatic cancer (PC) in many ways. The purpose of this study is to explore the related research fields of NDDS for PC from the perspective of bibliometrics. Methods: Articles and reviews on NDDS for PC published between 2003 and 2022 were obtained from the Web of Science Core Collection. CiteSpace, VOSviewer, R-bibliometrix, and Microsoft Excel were comprehensively used for bibliometric and visual analysis. Results: A total of 1329 papers on NDDS for PC were included. The number of papers showed an upward trend over the past 20 years. The United States contributed the most papers, followed by China, and India. Also, the United States had the highest number of total citations and H-index. The institution with the most papers was Chinese Acad Sci, which was also the most important in international institutional cooperation. Professors Couvreur P and Kazuoka K made great achievements in this field. JOURNAL OF CONTROLLED RELEASE published the most papers and was cited the most. The topics related to the tumor microenvironment such as "tumor microenvironment", "tumor penetration", "hypoxia", "exosome", and "autophagy", PC treatment-related topics such as "immunotherapy", "combination therapy", "alternating magnetic field/magnetic hyperthermia", and "ultrasound", and gene therapy dominated by "siRNA" and "miRNA" were the research hotspots in the field of NDDS for PC. Conclusion: This study systematically uncovered a holistic picture of the performance of NDDS for PC-related literature over the past 20 years. We provided scholars to understand key information in this field with the perspective of bibliometrics, which we believe may greatly facilitate future research in this field.

Transcytosis-enabled active extravasation of tumor nanomedicine

Extravasation is the first step for nanomedicines in circulation to reach targeted solid tumors. Traditional nanomedicines have been designed to extravasate into tumor interstitium through the interendothelial gaps previously assumed rich in tumor blood vessels, i.e., the enhanced permeability and retention (EPR) effect. While the EPR effect has been validated in animal xenograft tumor models, accumulating evidence implies that the EPR effect is very limited and highly heterogeneous in human tumors, leading to highly unpredictable and inefficient extravasation and thus limited therapeutic efficacy of nanomedicines, including those approved in clinics. Enabling EPR-independent extravasation is the key to develop new generation of nanomedicine with enhanced efficacy. Transcytosis of tumor endothelial cells can confer nanomedicines to actively extravasate into solid tumors without relying on the EPR effect. Here, we review and prospectthe development of transcytosis-inducing nanomedicines, in hope of providing instructive insights for design of nanomedicines that can undergo selective transcellular transport across tumor endothelial cells, and thus inspiring the development of next-generation nanomedicines for clinical translation.

Dual αV-integrin and neuropilin-1 targeting peptide CEND-1 plus nab-paclitaxel and gemcitabine for the treatment of metastatic pancreatic ductal adenocarcinoma: a first-in-human, open-label, multicentre, phase 1 study

BACKGROUND

CEND-1 is a novel cyclic peptide that targets αV integrins and neuropilin-1 and enhances tumour delivery of co-administered anticancer drugs. We investigated the safety, tolerability, and biological activity of CEND-1 in patients with metastatic pancreatic ductal adenocarcinoma in combination with nab-paclitaxel and gemcitabine.

METHODS

This open-label, multicentre, phase 1 study, conducted at three hospitals in Australia, enrolled participants aged 18 years or older with histologically confirmed metastatic pancreatic ductal adenocarcinoma who had one or more lesions measurable on MRI or CT, an Eastern Cooperative Oncology Group performance status score of 0 or 1, and a life expectancy of at least 3 months. Exclusion criteria included previous chemotherapy and brain metastases or other malignancy (unless receiving curative intent). There was no randomisation or masking. CEND-1 monotherapy was given as an intravenous fluid bolus on day 1 of a run-in phase of 7 days (0·2-3·2 mg/kg) followed by CEND-1 plus intravenous gemcitabine (1000 mg/m2) and nab-paclitaxel (125 mg/m2) on days 1, 8, and 15 of 28-day treatment cycles until disease progression. The primary safety endpoints were incidence, severity, and duration of treatment-emergent and treatment-related adverse events; overall survival; and clinical laboratory results, which were all assessed in the safety population. This study is registered with ClinicalTrials.gov, NCT03517176, and the Australian New Zealand Clinical Trials Registry, ACTRN12618000804280.

FINDINGS

Between Aug 13, 2018, and Nov 30, 2019, 31 patients were enrolled (eight in the dose-escalation phase [cohort 1a] and 23 in the expansion phase [cohort 1b]). Two patients were excluded from the efficacy population. No CEND-1 dose-limiting toxicities were observed in the safety population (n=31). The most common grade 3 or 4 events were neutropenia (17 [55%] patients), anaemia (eight [26%]), leukopenia (five [16%]), and pulmonary embolism (four [13%]). Serious adverse events occurred in 22 (71%) patients, mostly related to disease progression. Ten deaths occurred during the study due to progression of metastatic pancreatic cancer (n=9) and a left middle cerebral artery stroke (n=1). In the efficacy population (n=29), 17 (59%) patients had an objective response, including one complete response and 16 partial responses. After a median follow-up of 26 months (IQR 24-30), median overall survival was 13·2 months (95% CI 9·7-22·5).

INTERPRETATION

CEND-1 with nab-paclitaxel and gemcitabine has an acceptable safety profile, with no dose-limiting toxicities and encouraging activity. Adverse events were generally consistent with those seen with nab-paclitaxel and gemcitabine. Further randomised trials to determine the efficacy of CEND-1 are warranted.

FUNDING

DrugCendR Australia Pty.

Novel Cocktail Therapy Based on a Nanocarrier with an Efficient Transcytosis Property Reverses the Dynamically Deteriorating Tumor Microenvironment for Enhanced Immunotherapy

The immune checkpoint blockade (ICB) faces a low response rate in clinical cancer treatment. Chemotherapy could enhance the response rate of the ICB, but patients would suffer from side effects. The off-target toxicity could be reduced by loading the chemotherapeutic agent through nanocarriers. Therefore, we developed a polymeric carrier for doxorubicin (DOX) loading to form DOX nanoparticles (DOX NPs), which were spatiotemporally responsive to the tumor microenvironment (TME). DOX NPs had an efficient transcytosis property for deep tumor infiltration and sustained drug release ability. Unfortunately, a binary therapy of DOX NPs and ICB induces tumor adaptive resistance and causes dynamic deterioration of the TME. We propose for the first time that TGF-β1 is a major cause of tumor adaptive resistance and developed an immune cocktail therapy containing DOX NPs, ICB, and TGF-β1 gene silencing nanoparticles. This therapy successfully overcame tumor adaptive resistance by reversing the immunosuppressive TME and achieved enhanced tumor treatment efficiency.