Vascular-targeted Drug Research Articles

Organ-on-a-Chip Approach for Accelerating Blood-Brain Barrier Nanoshuttle Discovery.

Organ-on-a-chip, which recapitulates the dynamics of in vivo vasculature, has emerged as a promising platform for studying organ-specific vascular beds. However, its practical advantages in identifying vascular-targeted drug delivery systems (DDS) over traditional in vitro models remain underexplored. This study demonstrates the reliability and efficacy of the organ-on-a-chip in screening efficient DDS by comparing its performance with that of a conventional transwell, both designed to simulate the blood-brain barrier (BBB). The BBB nanoshuttles discovered through BBB Chip-based screening demonstrated superior functionality in vivo compared to those identified using transwell methods. This enhanced effectiveness is attributed to the BBB Chip's accurate replication of the structure and dynamics of the endothelial glycocalyx, a crucial protective layer within blood vessels, especially under shear stress. This capability of the BBB Chip has enabled the identification of molecular shuttles that efficiently exploit the endothelial glycocalyx, thereby enhancing transendothelial transport efficacy. Our findings suggest that organ-on-a-chip technology holds considerable promise for advancing research in vascular-targeted DDS due to its accurate simulation of molecular transport within endothelial systems.

Antiangiogenic therapy: how far is it to upgrade?

AbstractEarly vascular-targeted drugs represented by VEGF single-pathway inhibitors pioneered the idea of regulating the tumor growth microenvironment and enhanced the chemotherapy effect in a variety of tumors. However, their shortcomings of “only winning PFS but not OS” have gradually revealed and warned that drug-resistant growth of tumors is unavoidable after long-term use. The activation of intracellular bypass signaling after inhibiting a single target may be an important reason. In order to eliminate this problem, attempts have been made to expand the combination of drug types and increase the intensity of drug treatment. The possibility of replacing single-target anti-angiogenic therapeutic drugs with multiple targets has also be explored. A new generation of “dual-dimension, multi-pathway” drugs that simultaneously inhibit multiple targets both in tumors and microvascular endothelial cells can be used either as single drugs in multiple tumor types, or in combination with chemotherapy, EGFR-TKI, or even immunological drugs. It demonstrates good efficacy and great potential and hope for upgrading vascular targeted therapy. It also enlightens us that future treatment and new drug development strategies cannot rely solely on the most precise target inhibition, but should have a “dual-dimension, multi-pathway” integration concept that looks at the overall situation from one corner.

Comparison between different treatment regimens of vascular targeting drug to malignant pleural effusion in patients with lung cancer: A Bayesian network meta-analysis.

The presence of malignant pleural effusion in lung cancer patients often suggests a poor prognosis. We plan to investigate which regimen of vascular targeting drug is preferable to control the malignant pleural effusion in such patients. Two investigators dependently searched and screened for randomized controlled trials in PubMed, Embase, Web of Science and China National Knowledge Infrastructure from the database inception to August 2022. R software was applied to build a network model in Bayesian method. Objective response rate of malignant pleural effusion is the primary outcome measure. Besides, the incidence of 3 adverse events were compared, including gastrointestinal reaction, leukopenia and hypertension. Due to the disconnection of network, we analysis and discuss the short-term treatment (3-4 weeks) and long-term treatment (6-12 weeks) respectively. 31 studies with 2093 patients were identified. Four targeting drugs contain bevacizumab (Bev), anlotinib, apatinib and Endostar. Two administration routes include intracavity perfusion (icp) and intravenous injection. Based on the current evidence, for short-term treatments, compared with single-agent chemotherapy (CT), Bev_icp + CT, anlotinib + CT, Bev_icp and anlotinib + endorstar_icp present better objective response, and no statistical significance was found in objective response between Bev_icp + CT, anlotinib + CT and Bev_icp. For long-term treatments, compared with doublet or triplet chemotherapy (2CT or 3CT), Bev_icp + 2CT, apatinib + 2CT, Bev_icp + 3CT, and Bev_intravenous injection + 2CT are more effective option, but no statistical significance was found in objective response between the 4 combination regimens with chemotherapy. Our findings suggest that no statistical significance between above vascular targeting regimens. Pathological type of lung cancer may affect the effect of bevacizumab intracavity infusion plus chemotherapy. The influence of different administration routes of vascular targeting drugs on efficacy remains to be investigated. There are some concerns with the quality of the studies, and some limitations should be considered when interpreting these results, which includes limited geographical region and sample size of studies. Despite these limitations, this study may inform vascular targeting therapy choice in such a patient population.

Anlotinib plus PD-1 inhibitors as chemo-free therapy in advanced or metastatic esophageal cancer: Updated results from a retrospective real-world study.

310 Background: Compared to standard chemotherapy, immune checkpoint inhibitors monotherapy and combined with chemotherapy regimens have been shown significant benefits for patients with advanced or metastatic esophageal cancer in both second-line and first-line treatment, respectively. Anlotinib was an effective second-line monotherapy for esophageal squamous cell carcinoma in China and the combination of anlotinib and immunotherapy might be a promising strategy. The study aimed to investigate the efficacy and safety of anlotinib plus PD-1 inhibitors during the treatment of esophageal cancer in the real world setting. Methods: This is a multicenter real-world study in patients with unresectable locally advanced, recurrent or metastatic esophageal cancer, who would benefit from anlotinib plus a PD-1 inhibitor under the doctor's evaluation. The enrolled patients received treatment according to physicians. The primary endpoint was PFS, and secondary endpoints included ORR, DCR and OS. The response to treatment was evaluated according to RECIST version 1.1. In addition, adverse events were evaluated by CTCAE v5.0. Results: Between May 2020 and Sep 2022, 207 pts were enrolled. 109 comprised the evaluable population. In the full analysis set, 203 patients were squamous cell and 4 were adenocarcinoma histology. 137 of 207 (66.2%) pts were male. 44(21.3%) had an ECOG performance status of 0, 136 (65.7%) status of 1 and 27 (13.0%) status of ≥2. 47 pts had previously used anti-PD-1/PD-L1 antibody or vascular targeting drugs, of which 8 cases had combined anti-PD-1/PD-L1 antibody and vascular targeting drugs. Among the 109 evaluable pts, 17 (15.6%) pts received first-line therapy, 64 (58.7%) second-line and 28(25.7%) third & above line. Of which, 5 patients achieved complete response (CR), 32 pts partial response (PR), 62 pts stable disease (SD), illustrating an ORR of 34.0% (95%CI 25.1-43.6) and a DCR of 90.8%(95%CI 83.8-95.5). In the first line therapy, ORR was 47.1% and DCR was 88.2%. In the second line therapy, ORR was 32.8% and DCR was 96.9%. In the third & above line, ORR with 28.6% and DCR with 78.6% were observed. Median PFS was not reached, 6m-PFS rate was 87.9%. Treatment related adverse events (TRAEs) were reported in 55 pts (50.5%). 6 patients had grade 3 or more TRAEs. Conclusions: Anlotinib plus PD-1 inhibitors for advanced or metastatic esophageal cancer demonstrated a promising clinical benefit and a manageable safety profile. Further investigation in larger cohorts and even randomized controlled studies is warranted. Clinical trial information: NCT04966611 .

Shear stress regulation of nanoparticle uptake in vascular endothelial cells.

Nanoparticles (NPs) hold tremendous targeting potential in cardiovascular disease and regenerative medicine, and exciting clinical applications are coming into light. Vascular endothelial cells (ECs) exposure to different magnitudes and patterns of shear stress (SS) generated by blood flow could engulf NPs in the blood. However, an unclear understanding of the role of SS on NP uptake is hindering the progress in improving the targeting of NP therapies. Here, the temporal and spatial distribution of SS in vascular ECs and the effect of different SS on NP uptake in ECs are highlighted. The mechanism of SS affecting NP uptake through regulating the cellular ROS level, endothelial glycocalyx and membrane fluidity is summarized, and the molecules containing clathrin and caveolin in the engulfment process are elucidated. SS targeting NPs are expected to overcome the current bottlenecks and change the field of targeting nanomedicine. This assessment on how SS affects the cell uptake of NPs and the marginalization of NPs in blood vessels could guide future research in cell biology and vascular targeting drugs.

Pregnancy outcomes in women with pulmonary hypertension: a retrospective study in China

BackgroundIn recent years, with the development of monitoring conditions and the application of pulmonary vascular-targeted drugs, pregnancy outcomes in women with pulmonary hypertension (PH) have improved, but the maternal mortality rate is still high. The purpose of this study was to describe the maternal-foetal outcomes in pregnant women with PH.MethodsThe clinical data of 154 pregnant women with PH who were admitted to the Third Affiliated Hospital of Guangzhou Medical University from January 2011 to December 2020 were collected and descriptively analysed.ResultsAmong the 154 pregnant women with PH, 6 (3.9%) had idiopathic pulmonary arterial hypertension (iPAH), 41 (26.6%) had pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD-PAH), 45 (29.2%) had PAH related to other diseases (oPAH), and 62 (40.3%) had PH related to left heart disease (LHD-PH). The systolic pulmonary artery pressure (sPAP) was 36–49 mmHg in 53.2% of the patients, 50–69 mmHg in 22.1% of the patients and ≥ 70 mmHg in 24.7% of the patients. Five (3.2%) pregnant women died within 1 week after delivery; iPAH patients had the highest mortality rate (3/6, 50%). Fifty-four patients (35.1%) were admitted to the intensive care unit (ICU), and the incidence of heart failure during pregnancy was 14.9%. A total of 70.1% of the patients underwent caesarean section; 42.9% had premature infants; 28.6% had low-birth-weight (LBW) infants; 13.0% had very-low-birth-weight (VLBW) infants; 3.2% had extremely-low-birth-weight (ELBW) infants; 61% had small for gestational age (SGA) infants; and 1.9% experienced neonatal mortality.ConclusionThere were significant differences in the maternal-foetal outcomes in the iPAH, CHD-PAH, oPAH and LHD-PH groups. Maternal mortality was highest in the iPAH group; therefore, iPAH patients should be advised to prevent pregnancy. Standardized and multidiscipline-assisted maternal management is the key to improving maternal-foetal outcomes.

Clinical effect of vascular targeting drugs combined with chemotherapy in advanced liver cancer

Clinical effect of vascular targeting drugs combined with chemotherapy in advanced liver cancer

Real-world effectiveness of anlotinib plus PD-1 inhibitors as chemo-free therapy in advanced or metastatic esophageal cancer.

e16052 Background: Immunotherapy, particularly with anti-PD-1/PD-L1 antibodies, has shown therapeutic efficacy in various malignancies. Compared with chemotherapy, anti-PD-1 antibody monotherapy improved the median overall survival in advanced or metastatic esophageal cancer. The combination of an anti-PD-1/PD-L1 antibody with an angiogenesis inhibitor has shown efficacy in many cancers which including esophageal cancer. The purpose of this study is to investigate the efficacy and safety of anlotinib plus PD-1 inhibitors as chemo-free therapy during the treatment of esophageal cancer in the real world setting. Methods: This prospective, multicenter real-world study (NCT04966611) evaluated the efficacy and safety of anlotinib plus PD-1 inhibitors in the chemo-free therapy setting for advanced or metastatic esophageal cancer patients (pts). Primary endpoint was evaluation of PFS (progression-free survival), and secondary endpoints included ORR (objective response rate), DCR (disease control rate) and OS (overall survival). The response to treatment was evaluated according to RECIST version 1.1. In addition, adverse events were evaluated by CTCAE v5.0. Results: Between May 2020 and Dec 2021, 50 pts were enrolled. 45 comprised the evaluable population. In the full analysis set, 44 had squamous cell and 1 patient had adenocarcinoma histology. 29 (64.4%) of 45 pts were male. 10 (22.2%) had an ECOG performance status of 0, 32 (71.1%) status of 1 and 3 (6.7%) status of 2. Twenty (44.4%) pts had distant metastases and 29(64.4%) pts had comorbidities. 15 pts had previously used anti-PD-1/PD-L1 antibody or vascular targeting drugs, of which 5 cases had combined the two drugs. Among all evaluable pts, 5(11.1%) pts received first-line, 27(60.0%) second-line and 13(28.9%) third & above line therapy. Among all pts, 1 patient achieved complete response (CR), 16 pts partial response (PR), 25 pts stable disease (SD), illustrating an ORR of 37.8% and a DCR of 93.3%. In the first line therapy, ORR was 60.0%, DCR was 100%.In the second line therapy, ORR was 37.0%, DCR was 96.3%. In the third & above line, ORR with 30.8%, DCR with 84.6% was observed. Median PFS was not reached. Treatment related adverse events (trAEs) were reported in 24 pts(53.3%). No patient had grade 3 or more trAEs. Conclusions: Anlotinib plus PD-1 inhibitors in chemo-free therapy for advanced or metastatic esophageal cancer was active and showed excellent tumor response and was generally well tolerated. Further investigation is required in a larger real-world cohort to validate the benefit of anlotinib plus PD-1 inhibitor in esophageal cancer. Clinical trial information: NCT04966611.

3-D Super-Resolution Ultrasound Imaging for Monitoring Early Changes in Breast Cancer after Treatment with a Vascular-Disrupting Agent.

The purpose of this research project was to evaluate the use of 3-dimensional (3-D) super-resolution ultrasound (SR-US) imaging to assess any early changes in breast cancer after treatment with a vascular-disrupting agent (VDA). A Vevo 3100 ultrasound system (FUJIFILM VisualSonics Inc) equipped with an MX 201 transducer was used for image acquisition. A total of 2.5 × 107 microbubbles (MBs) were injected into the tail vein of anesthetized breast cancer-bearing mice using repeat bolus injections every 5 min. A total of 10 stacks of ultrasound images were collected as the transducer was mechanically moved across the tumor at 0.6 mm intervals yielding a 6-mm thick volume. At each tumor location, a stack contained 1 × 104 frames of ultrasound data that were acquired at 463 frames/sec and stored as in-phase/quadrature (IQ) format. After motion correction, each temporal stack of ultrasound images was processed separately for clutter signal removal, which was followed by MB localization and enumeration before generation of the final SR-US image. After reconstruction of the 3-D SR-US volume dataset, the tumor microvasculature was enhanced using a multiscale vessel enhancement filter. Vessels from the resultant microvascular network were then segmented using an adaptive thresholding method. Finally, mean microvascular density (MVD) measurements from each tumor volume were computed as a summarizing statistic. While no differences were found between baseline SR-US image-derived measures of MVD (p = 0.76), these same measurements were significantly lower at 24 h after VDA treatment (p < 0.001). Overall, 3-D SR-US imaging detected early tumor changes following treatment with a vascular-targeted drug.

Abstract 2797: Changes in the phenotype of macrophages and CD8+ T Cells in the perivascular niche of prostate tumours following androgen deprivation

Abstract Men with intermediate/high-risk, localized prostate cancer usually receive neoadjuvant androgen deprivation therapy (ADT). Although this markedly reduces tumor burden, it may not be curative and over time cancer cells develop resistance to ADT causing the tumor to regrow and spreads to other sites like the bones. Tumors are then termed ‘castration resistant' (CR) and require more aggressive forms of treatment like radical prostatectomy (RP) and chemotherapy. These can have unpleasant side effects so preventing the development of castration resistance and subsequent tumor regrowth/metastasis, would be highly beneficial for patients. A distinct subset of perivascular (PV) tumor-associated macrophages (TAMs) expressing the cell-surface receptor, MRC1, has been shown to be proangiogenic, immunosuppressive and to stimulate tumor regrowth after chemotherapy, irradiation or vascular targeting drugs. In the current study, we have examined the density and phenotype of TAMs in PV vs non-PV areas of localized, human prostate tumors and orthotopic mouse (Myc-CaP) tumors following neoadjuvant ADT or castration respectively. In human tumors, MRC1+ TAMs accumulated at highest density around stromal blood vessels, and were abundant in these sites following ADT. In mice, castration markedly reduced primary tumor growth and changed the distribution and phenotype of TAMs and cytotoxic CD8+ T lymphocytes (CTLs) just prior to the development of CR. In PV areas of tumors in sham-castrated (i.e. control) mice there were significantly more TAMs expressing MRC1 and the broad-spectrum negative checkpoint regulator, VISTA than in non-PV areas. This was accompanied by the preferential accumulation of CTLs around blood vessels (contrasting with the even distribution of CD4+ (helper) cells and CD4+FOXP3+ Tregs across PV and non-PV areas). Following castration, the PV density of MRC1+ and VISTA+ TAMs was markedly increased, along with that of CTLs expressing the cytotoxic protease, granzyme B - a marker of active CTLs. Although these cells may cross the vasculature into tumors in an active state, passing through a PV niche enriched in VISTA+ TAMs would likely suppress their cytotoxic function before they progressed into the tumor mass. An interesting picture is, therefore, emerging of tumor-promoting TAMs accumulating around blood vessels after various forms of treatment, where they regulate a number of important events including the extravasation and function of various immune effectors. Citation Format: Haider Al-janabi, Xuan Pu, Munitta Muthana, Ning Wang, Mateus Crespo, Bora Gurel, Johann De Bono, Janet E. Brown, Claire E. Lewis. Changes in the phenotype of macrophages and CD8+ T Cells in the perivascular niche of prostate tumours following androgen deprivation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2797.

Deformable microparticles for shuttling nanoparticles to the vascular wall.

Vascular-targeted drug carriers must localize to the wall (i.e., marginate) and adhere to a diseased endothelium to achieve clinical utility. The particle size has been reported as a critical physical property prescribing particle margination in vitro and in vivo blood flows. Different transport process steps yield conflicting requirements-microparticles are optimal for margination, but nanoparticles are better for intracellular or tissue delivery. Here, we evaluate deformable hydrogel microparticles as carriers for transporting nanoparticles to a diseased vascular wall. Depending on microparticle modulus, nanoparticle-loaded poly(ethylene glycol)-based hydrogel microparticles delivered significantly more 50-nm nanoparticles to the vessel wall than freely injected nanoparticles alone, resulting in >3000% delivery increase. This work demonstrates the benefit of optimizing microparticles' efficient margination to enhance nanocarriers' transport to the vascular wall.

Development and Characterization of PLGA-Based Multistage Delivery System for Enhanced Payload Delivery to Targeted Vascular Endothelium.

Vascular-targeted drug delivery remains an attractive platform for therapeutic and diagnostic interventions in human diseases. This work focuses on the development of a poly-lactic-co-glycolic-acid (PLGA)-based multistage delivery system (MDS). MDS consists of two stages: a micron-sized PLGA outer shell and encapsulated drug-loaded PLGA nanoparticles. Nanoparticles with average diameters of 76, 119, and 193nm are successfully encapsulated into 3-6µm MDS. Sustained in vitro release of nanoparticles from MDS is observed for up to 7 days. Both MDS and nanoparticles arebiocompatible with human endothelial cells. Sialyl-Lewis-A (sLeA ) is successfully immobilized on the MDS and nanoparticle surfaces to enable specific targeting of inflamed endothelium. Functionalized MDS demonstrates a 2.7-fold improvement in endothelial binding compared to PLGA nanoparticles from human blood laminar flow. Overall, the presented results demonstrate successful development and characterization of MDS and suggest that MDS can serve as an effective drug carrier, which can enhance the margination of nanoparticles to the targeted vascular wall.

The Tumor Vessel Targeting Strategy: A Double-Edged Sword in Tumor Metastasis.

Tumor vessels provide essential paths for tumor cells to escape from the primary tumor and form metastatic foci in distant organs. The vessel targeting strategy has been widely used as an important clinical cancer chemotherapeutic strategy for patients with metastatic tumors. Our review introduces the contribution of angiogenesis to tumor metastasis and summarizes the application of Food and Drug Administration (FDA)-approved vessel targeting drugs for metastatic tumors. We recommend the application and mechanisms of vascular targeting drugs for inhibiting tumor metastasis and discuss the risk and corresponding countermeasures after vessel targeting treatment.

Abstract LB-136: Targeting perivascular macrophages to prevent castration resistance in men with high-risk, localized prostate cancer

Abstract Background: Men with intermediate/high-risk, localised prostate cancer are usually offered androgen deprivation therapy (ADT) and if this fails, radical prostatectomy. Men understandably prefer not to have the latter where possible as it often leads to unpleasant side effects like urinary incontinence and erectile dysfunction. So, maximising the efficacy of ADT and/or preventing subsequent castration resistance is of clinical importance. A distinct subset of macrophages in tumours - those that make intimate contact with the abluminal side of tumour blood vessels and express high levels of MRC1, TIE2, CXCR4 and VEGFA - have been shown to play a crucial role in tumour relapse after chemotherapy by stimulating tumour angiogenesis and regrowth, as well as the escape of metastasizing cancer cells into the circulation, and suppression of tumour-infiltrating T cells. These perivascular (PV) cells have also been shown to stimulate tumour regrowth after irradiation and treatment with vascular targeting drugs. In this project, we investigated the effects of castration (which mimics the effects of ADTs) on PV macrophages in a syngeneic, orthotopic model of localised prostate cancer. Methods: Mice bearing established, LUC-expressing Myc-CaP tumours were either castrated or sham-castrated at day 10 post-inoculation and tumour growth assessed using the IVIS Imaging system. Multicolour immunofluorescent analysis of tumour sections (for CD31, MRC1, F4/80 and DAPI) was then performed on sections of excised tumours to assess the accumulation of PV macrophage just before, and immediately after, the regrowth of tumours. Results: Castration caused a marked delay in tumour growth in this mouse model with castration resistance evident within 2 weeks when tumours started to grow vigorously. Both the number and proportion of MRC1+ macrophages making direct contact with the abluminal surface of CD31+ blood vessels increased markedly just prior to castration resistance, and was persisted in tumours that had regrown to the size of sham-castrated ones at the end of the experiment. Conclusion: Our data indicate that PV MRC1+ macrophages may play a role in the development of castration resistance and/or subsequent tumour regrowth in mouse Myc-CaP tumours. We are currently investigating this using MRC1-targeting liposomes to inhibit the tumour-promoting functions of PV TAMs in mouse prostate tumours. We are also examining the accumulation and function of PV macrophages in AADT-responsive versus castration resistant localised human prostate tumours. It is hoped that these studies will lead to the use of macrophage-targeting liposomes to enhance the efficacy of ADTs in men with localised prostate cancer. Citation Format: Xuan Pu, Haider AL-Janabi, Ning Wang, Munitta Muthana, Janet Brown, Claire Lewis. Targeting perivascular macrophages to prevent castration resistance in men with high-risk, localized prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-136.

Preparation of truncated tissue factor antineuropilin-1 monoclonal antibody conjugate and identification of its selective thrombosis in tumor blood vessels.

In recent decades, selectively inducing tumor vascular thrombosis, followed by necrosis of tumor tissues has been a promising and potential anticancer strategy. In this report, we prepared a kind of vascular targeting drug that consists of anti-neuropilin-1 monoclonal antibody (anti-NRP-1 mAb) and truncated tissue factor (tTF). Anti-NRP-1 mAb could guide tTF to the surface of tumor vascular endothelial cells and lead to subsequent vascular embolization. This vascular targeting drug, which is also one of the antibody drug conjugates, was generated using a coupling method with water-soluble 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccimide. Afterwards, in-vitro and in-vivo assays were performed to characterize its potential coagulation ability and antitumor activity. In-vitro experiments indicated that tTF-anti-NRP-1 monoclonal antibody (tTF-mAb) retained both the targeting activity of anti-NRP-1 mAb and the procoagulant activity of tTF. Live imaging system was used to assess its biodistribution and tumor-binding capability, which also yielded promising results. Furthermore, in-vivo studies showed that tTF-mAb was capable of significantly inducing tumor vascular thrombosis and inhibiting tumor growth in nude mice bearing subcutaneous xenografts, and histopathologic changes were rarely observed in normal organs.

A comparison of CD105 and CD31 expression in tumor vessels of hepatocellular carcinoma by tissue microarray and flow cytometry.

Tumor endothelial cells (TECs) have been isolated from solid tumors by using immunological magnetic beads and magnetic active cell sorting, and lead to a more precise way to investigate tumor angiogenesis as well as screening of vascular targeting drugs. However, the question of which endothelial marker is a stable molecular signature in TECs and can be used for the isolation of TECs from tumor tissues remains unclear. In this study, we investigated the endothelial markers CD105 and CD31 in the tumor vessels from 90 patients with hepatocellular carcinoma (HCC) by tissue microarray, in addition to their expression in TECs isolated from fresh tissues resected from 11 patients with HCC by flow cytometry and confocal microscopy. The results revealed that among 90 cases of TMA, all tumor vessels were CD31 positive whereas 39 cases (43.3%) had little or no CD105 expression in tumors and their vessels but not peritumoral tissue spots, and that among these 39, 29 cases (74.4%) were poor-differentiated HCC. These findings were further verified by flow cytometry and confocal analysis of TECs isolated from HCC. Overall, the results suggested that CD105 may not be expressed in TECs derived from poor-differentiated HCC cases. In addition, combined with previous studies in which CD105 is not only expressed in TECs, but also in tumor cells, the results indicated a high risk of contamination with CD105+ tumor cells. Thus, there is a limitation to the use CD105 as an endothelial marker for the isolation of TECs.

NGR-hTNF in combination with best investigator choice in previously treated malignant pleural mesothelioma (NGR015): a randomised, double-blind, placebo-controlled phase 3 trial

Malignant pleural mesothelioma is an aggressive cancer with highly vascularised tumours. It has poor prognosis and few treatment options after failure of first-line chemotherapy. NGR-hTNF is a vascular-targeting drug that increases penetration of intratumoral chemotherapy and T-cell infiltration by modifying the tumour microenvironment. In this trial, we aimed to investigate the efficacy and safety of NGR-hTNF in patients with malignant pleural mesothelioma who had progressed during or after a first-line treatment. NGR015 was a randomised, double-blind, placebo-controlled phase 3 trial done in 41 centres in 12 countries. Eligible participants had malignant pleural mesothelioma of any histological subtype (epithelial, sarcomatoid, or mixed), were aged 18 years or older, and had an Eastern Cooperative Oncology Group performance status of 0-2 and radiologically documented progressive disease after one pemetrexed-based chemotherapy regimen. Participants were randomly assigned to receive weekly NGR-hTNF 0·8 μg/m2 intravenously plus best investigator choice (n=200), or placebo plus best investigator choice (n=200). Best investigator choice was decided before random assignment and could be single-agent gemcitabine (1000-1250 mg/m2 intravenously), vinorelbine (25 mg/m2 intravenously or 60 mg/m2 orally), doxorubicin (60-75 mg/m2 intravenously), or best supportive care only. Patients were randomised (1:1) with a block size of four after stratification for performance status and best investigator choice. The primary study endpoint was overall survival in the intention-to-treat population. The trial is closed to new participants and is registered with ClinicalTrials.gov (NCT01098266). Between April 12, 2010 and Jan 21, 2013, we enrolled 400 eligible participants. 381 (95%) of 400 patients were selected to receive chemotherapy before all participants were randomly assigned to receive NGF-hTNF plus best investigator choice (n=200) or placebo plus best investigator choice (n=200). At the cutoff date (April 29, 2014), the median follow-up was 18·7 months (IQR 15·1-24·4), and overall survival did not differ between the two treatment groups (median 8·5 months [95% CI 7·2-9·9] in the NGR-hTNF group vs 8·0 months [6·6-8·9] in the placebo group; hazard ratio 0·94, 95% CI 0·75-1·18; p=0·58). Grade 3 or worse study-emergent adverse events occurred in 136 (70%) of patients receiving NGR-hTNF versus 118 (61%) of patients receiving placebo, with the most common being neutropenia (35 [18%] of 193 patients vs 36 [19%] of 193 patients), pain (11 [6%] vs 16 [8%]), dyspnoea (nine [5%] vs seven [4%]), and chills (nine [5%] vs none). 50 (26%) patients in the NGR-hTNF group had a serious adverse event, compared with 47 (24%) in the placebo group. Treatment-related serious adverse events occurred in 17 (9%) patients in the NGR-hTNF group and 20 patients (10%) in the placebo group. There were 12 deaths in the NGR-hTNF group and 13 deaths in the placebo group, but none were treatment related. The study did not meet its primary endpoint. The hypothesis-generating findings from the subgroup analyses deserve a confirmatory randomised trial because patients who rapidly progress after first-line treatment have a poor prognosis. MolMed.

Margination of Fluorescent Polylactic Acid–Polyaspartamide based Nanoparticles in Microcapillaries In Vitro: the Effect of Hematocrit and Pressure

The last decade has seen the emergence of vascular-targeted drug delivery systems as a promising approach for the treatment of many diseases, such as cardiovascular diseases and cancer. In this field, one of the major challenges is carrier margination propensity (i.e., particle migration from blood flow to vessel walls); indeed, binding of these particles to targeted cells and tissues is only possible if there is direct carrier–wall interaction. Here, a microfluidic system mimicking the hydrodynamic conditions of human microcirculation in vitro is used to investigate the effect of red blood cells (RBCs) on a carrier margination in relation to RBC concentration (hematocrit) and pressure drop. As model drug carriers, fluorescent polymeric nanoparticles (FNPs) were chosen, which were obtained by using as starting material a pegylated polylactic acid–polyaspartamide copolymer. The latter was synthesized by derivatization of α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) with Rhodamine (RhB), polylactic acid (PLA) and then poly(ethyleneglycol) (PEG) chains. It was found that the carrier concentration near the wall increases with increasing pressure drop, independently of RBC concentration, and that the tendency for FNP margination decreases with increasing hematocrit. This work highlights the importance of taking into account RBC–drug carrier interactions and physiological conditions in microcirculation when planning a drug delivery strategy based on systemically administered carriers.

Exploring deformable particles in vascular-targeted drug delivery: Softer is only sometimes better.

The ability of vascular-targeted drug carriers (VTCs) to localize and bind to a targeted, diseased endothelium determines their overall clinical utility. Here, we investigate how particle modulus and size determine adhesion of VTCs to the vascular wall under physiological blood flow conditions. In general, deformable microparticles (MPs) outperformed nanoparticles (NPs) in all experimental conditions tested. Our results indicate that MP modulus enhances particle adhesion in a shear-dependent manner. In low shear human blood flow profiles invitro, low modulus particles showed favorable adhesion, while at high shear, rigid particles showed superior adhesion. This was confirmed invivo by studying particle adhesion under venous shear profiles in a mouse model of mesenteric inflammation, where MP adhesion was 127% greater (p<0.0001) for low modulus particles compared to more rigid ones. Mechanistically, we establish that particle collisions with leukocytes drive these trends, rather than differences in particle deformation, localization, or detachment. Overall, this work demonstrates the importance of VTC modulus as a design parameter for enhanced VTC interaction with vascular walls, and thus, contributes important knowledge for development of successful clinical theranostics with applications for many diseases.

Effect of anticoagulants on the protein corona-induced reduced drug carrier adhesion efficiency in human blood flow.

This study addresses the impact of anticoagulant on altering the extent of the previously observed protein corona-induced adhesion reduction of vascular-targeted drug carriers in human blood flows. Specifically, serum blood flow (no anticoagulant) magnifies the negative effect of the plasma protein corona on drug carrier adhesion relative to citrated or heparinized blood flows. Overall, the results from this work suggest that serum better predicts targeted drug carrier adhesion efficiency in vivo compared to anticoagulant containing plasma. Furthermore, this study offers critical insight into the importance of how the choice of anticoagulant can greatly affect drug delivery-related processes in vitro.