Development and evaluation of an isolated limb infusion model for investigation of drug delivery kinetics to solid tumors by thermosensitive liposomes and hyperthermia.

The combined administration of thermosensitive liposomes (TSLs) and hyperthermia (HT) has been increasingly shown to be a powerful tool for the treatment of solid tumors. At present, it is hypothesized that the circulation of TSLs through the vasculature of a heated tumor results in the rapid release of the entrapped drug, followed by its uptake and distribution within the tumor microenvironment. However, simple questions on the transport kinetics of TSLs through the heated tumor and how much drug is retained upon passage of TSLs through the tumor microcirculation have not been investigated in an experimental setting to-date.

Comparing the therapeutic potential of thermosensitive liposomes and hyperthermia in two distinct subtypes of breast cancer.

Local drug delivery of Doxorubicin (Dox) with thermosensitive liposomes (TSL) and hyperthermia (HT) has shown preclinically to achieve high local drug concentrations with good therapeutic efficacy. Currently, this is clinically studied for treatment of chest wall recurrence of breast cancer, however with various outcomes. This study examines the potency of neoadjuvant TSL HT combination therapy in two orthotopic mouse models of human breast cancer, MDA-MB-231 and T-47D, which morphologically correlate to mesenchymal and epithelial phenotypes, respectively.

Melanomas prevent endothelial cell death under restrictive culture conditions by signaling through AKT and p38 MAPK/ ERK-1/2 cascades.

Although melanoma progression and staging is clinically well characterized, a large variation is observed in pathogenesis, progression, and therapeutic responses. Clearly, intrinsic characteristics of melanoma cells contribute to this variety. An important factor, in both progression of the disease and response to therapy, is the tumor-associated vasculature.

Investigation of Particle Accumulation, Chemosensitivity and Thermosensitivity for Effective Solid Tumor Therapy Using Thermosensitive Liposomes and Hyperthermia.

Doxorubicin (Dox) loaded thermosensitive liposomes (TSLs) have shown promising results for hyperthermia-induced local drug delivery to solid tumors. Typically, the tumor is heated to hyperthermic temperatures (41-42 °C), which induced intravascular drug release from TSLs within the tumor tissue leading to high local drug concentrations (1-step delivery protocol). Next to providing a trigger for drug release, hyperthermia (HT) has been shown to be cytotoxic to tumor tissue, to enhance chemosensitivity and to increase particle extravasation from the vasculature into the tumor interstitial space.

EGFR targeted thermosensitive liposomes: A novel multifunctional platform for simultaneous tumor targeted and stimulus responsive drug delivery.

The epidermal growth factor receptor (EGFR) is a promising target for anti-cancer therapy. The aim of this study was to design thermosensitive liposomes (TSL), functionalized with anti-EGFR ligands for targeted delivery and localized triggered release of chemotherapy. For targeting, EGFR specific peptide (GE11) and Fab' fragments of cetuximab were used and the effect of ligand density on in vitro tumor targeting was investigated.

A Novel Combined Approach of Short-Chain Sphingolipids and Thermosensitive Liposomes for Improved Drug Delivery to Tumor Cells.

Despite the advantages of liposomal drug delivery, the bioavailability of the chemotherapeutic drugs to tumor cells is limited by their slow release from nanocarriers and low drug permeability across cell membranes. Drug encapsulation into stealth thermosensitive liposomes can improve drug delivery to tumors by combining efficient accumulation at tumors and the active release of the payload following remote heat triggering. Short-chain sphingolipids are known to enhance cellular uptake of amphiphilic drugs.

Targeting melanoma with immunoliposomes coupled to anti-MAGE A1 TCR-like single-chain antibody.

Therapy of melanoma using T-cells with genetically introduced T-cell receptors (TCRs) directed against a tumor-selective cancer testis antigen (CTA) NY-ESO1 demonstrated clear antitumor responses in patients without side effects. Here, we exploited the concept of TCR-mediated targeting through introduction of single-chain variable fragment (scFv) antibodies that mimic TCRs in binding major histocompatibility complex-restricted CTA. We produced scFv antibodies directed against Melanoma AntiGEn A1 (MAGE A1) presented by human leukocyte antigen A1 (HLA-A1), in short M1/A1, and coupled these TCR-like antibodies to liposomes to achieve specific melanoma targeting.

EGF-liposomes promote efficient EGFR targeting in xenograft colocarcinoma model.

Aim: Development of EGF-liposomes (LP-EGF) for selective molecules delivery in tumors expressing EGFR.

Material & Methods: In vitro cellular interaction of EGF-LP and nontargeted liposomes (LP-N) was assayed at 37 and 4 °C in cells expressing different EGFR levels. Receptor-mediated uptake was investigated by competition with a monoclonal antibody anti-EGFR.

In depth study on thermosensitive liposomes: Optimizing formulations for tumor specific therapy and in vitro to in vivo relations.

In numerous studies, thermosensitive liposomes (TSLs) for local heat-triggered delivery of Doxorubicin (Dox) to tumors have been investigated, with TSLs having different lipid formulations, drug loading methodology and testing procedures. To gain more insight in these parameters, we investigated TSLs with four variable DSPC-DPPC lipid ratios (50, 60, 70 or 80% DPPC and 5 mol% of DSPE-PEG2000) using either ammonium sulfate or a citrate buffer for Dox loading. Ammonium sulfate loading of Dox yielded more stable TSLs than citrate loading.

Investigation of Factors Determining the Enhanced Permeability and Retention Effect in Subcutaneous Xenografts.

Liposomal chemotherapy offers several advantages over conventional therapies, including high intratumoral drug delivery, reduced side effects, prolonged circulation time, and the possibility to dose higher. The efficient delivery of liposomal chemotherapeutics relies, however, on the enhanced permeability and retention (EPR) effect, which refers to the ability of macromolecules to extravasate leaky tumor vessels and accumulate in the tumor tissue. Using a panel of human xenograft tumors, we evaluated the influence of the EPR effect on liposomal distribution in vivo by injection of pegylated liposomes radiolabeled with (111)In.

Method of hyperthermia and tumor size influence effectiveness of doxorubicin release from thermosensitive liposomes in experimental tumors.

Systemic chemotherapy of solid tumors could be enhanced by local hyperthermia (HT) in combination with thermosensitive liposomes (TSL) as drug carriers. In such an approach, effective HT of the tumor is considered essential for successful triggering local drug release and targeting of the drug to the tumor. To investigate the effect of HT method on the effectiveness of drug delivery, a novel laser-based HT device designed for the use in magnetic resonance imaging (MRI) was compared systematically with the frequently used cold light lamp and water bath HT.

Formulation and optimization of idarubicin thermosensitive liposomes provides ultrafast triggered release at mild hyperthermia and improves tumor response.

Drug delivery through thermosensitive liposomes (TSL) in combination with hyperthermia (HT) has shown great potential. HT can be applied locally forcing TSL to release their content in the heated tumor resulting in high peak concentrations. To perform optimally the drug is ideally released fast (seconds) and taken up rapidly by tumor cells.

Development of a novel cyclic RGD peptide for multiple targeting approaches of liposomes to tumor region.

Liposomes containing cytotoxic agents and targeted with Arg-Gly-Asp based peptides have frequently been used against αvβ3 integrin on tumor neovasculature. However, like many other ligand modified liposomes these preparations suffered from enhanced uptake by the reticulo endothelial system (RES) and off-targeted interaction with integrin receptors vastly expressed in normal organs causing poor biodistribution and toxic effects. Here we mainly focus on development of a RGD-modified liposomal delivery system to enhance both targeting selectivity and tumor uptake.

Pharmacokinetics, Tissue Distribution and Therapeutic Effect of Cationic Thermosensitive Liposomal Doxorubicin Upon Mild Hyperthermia.

Purpose: To evaluate pharmacokinetic profile, biodistribution and therapeutic effect of cationic thermosensitive liposomes (CTSL) encapsulating doxorubicin (Dox) upon mild hyperthermia (HT).

Methods: Non-targeted thermosensitive liposomes (TSL) and CTSL were developed, loaded with Dox and characterized. Blood kinetics and biodistribution of Dox-TSL and Dox-CTSL were followed in B16BL6 tumor bearing mice upon normothermia (NT) or initial hyperthermia conditions.

Enhanced Specificity and Drug Delivery in Tumors by cRGD-Anchoring Thermosensitive Liposomes.

Purpose: To develop RGD-targeted thermosensitive liposomes with increased tumor retention, improving drug release efficiency upon mild hyperthermia (HT) in both tumor and angiogenic endothelial cells.

Methods: Standard termosensitive liposomes (TSL) and TSL containing a cyclic Arg-Gly-Asp (cRGD) pentapeptide with the sequence Arg-Cys-D-Phe-Asp-Gly (RGDf[N-Met]C) were synthetized, loaded with Dox and characterized. Temperature- and time-dependent drug release profiles were assessed by fluorometry.

Cetuximab-oxaliplatin-liposomes for epidermal growth factor receptor targeted chemotherapy of colorectal cancer.

Oxaliplatin (L-OH), a platinum derivative with good tolerability is currently combined with Cetuximab (CTX), a monoclonal antibody (mAb), for the treatment of certain (wild-type KRAS) metastatic colorectal cancer (CRC) expressing epidermal growth factor receptor (EGFR). Improvement of L-OH pharmacokinetics (PK) can be provided by its encapsulation into liposomes, allowing a more selective accumulation and delivery to the tumor. Here, we aim to associate both agents in a novel liposomal targeted therapy by linking CTX to the drug-loaded liposomes.

Plasma membrane targeting by short chain sphingolipids inserted in liposomes improves anti-tumor activity of mitoxantrone in an orthotopic breast carcinoma xenograft model.

Mitoxantrone (MTO) is clinically used for treatment of various types of cancers providing an alternative for similarly active, but more toxic chemotherapeutic drugs such as anthracyclines. To further decrease its toxicity MTO was encapsulated into liposomes. Although liposomal drugs can accumulate in target tumor tissue, they still face the plasma membrane barrier for effective intracellular delivery.

A Novel ¹¹¹In-Labeled Anti-Prostate-Specific Membrane Antigen Nanobody for Targeted SPECT/CT Imaging of Prostate Cancer.

Unlabelled: Prostate-specific membrane antigen (PSMA) is overexpressed in prostate cancer (PCa) and a promising target for molecular imaging and therapy. Nanobodies (single-domain antibodies, VHH) are the smallest antibody-based fragments possessing ideal molecular imaging properties, such as high target specificity and rapid background clearance. We developed a novel anti-PSMA Nanobody (JVZ-007) for targeted imaging and therapy of PCa.

C8-glycosphingolipids preferentially insert into tumor cell membranes and promote chemotherapeutic drug uptake.

Insufficient drug delivery into tumor cells limits the therapeutic efficacy of chemotherapy. Co-delivery of liposome-encapsulated drug and synthetic short-chain glycosphingolipids (SC-GSLs) significantly improved drug bioavailability by enhancing intracellular drug uptake. Investigating the mechanisms underlying this SC-GSL-mediated drug uptake enhancement is the aim of this study.

Short-chain glycoceramides promote intracellular mitoxantrone delivery from novel nanoliposomes into breast cancer cells.

Purpose: To improve therapeutic activity of mitoxantrone (MTO)-based chemotherapy by reducing toxicity through encapsulation in nanoliposomes and enhancing intracellular drug delivery using short-chain sphingolipid (SCS) mediated tumor cell membrane permeabilization.

Methods: Standard (MTOL) and nanoliposomes enriched with the SCS, C8-Glucosylceramide or C8-Galactosylceramide (SCS-MTOL) were loaded by a transmembrane ammonium sulphate gradient and characterized by DLS and cryo-TEM. Intracellular MTO delivery was measured by flow cytometry and imaged by fluorescence microscopy.

Targeted and heat-triggered doxorubicin delivery to tumors by dual targeted cationic thermosensitive liposomes.

Liposomal nanoparticles can circumvent toxicity of encapsulated chemotherapeutic drugs, but fall short in tumor-specific and efficient intracellular drug delivery. To overcome these shortcomings, we designed a multifunctional dual targeted, heat-responsive nanocarrier encapsulating doxorubicin (Dox) as a chemotherapeutic content. Dox-loaded cationic thermosensitive liposomes (Dox-CTSL) carry targeting functions addressing tumor cells and tumor vasculature and have a heat-responsive lipid bilayer.

[(111)In-DTPA]octreotide tumor uptake in GEPNET liver metastases after intra-arterial administration: an overview of preclinical and clinical observations and implications for tumor radiation dose after peptide radionuclide therapy.

Aims: With the aim to improve peptide receptor radionuclide therapy effects in patients with gastroenteropancreatic neuroendocrine tumor (GEPNET) liver metastases we explored the effect of intra-arterial (IA) administration of [(111)In-DTPA]octreotide ((111)In-DTPAOC) on tumor uptake in an animal model and in a patient study.

Methods: Preclinical study: After administering (111)In-DTPAOC intra-venously (IV) or IA, biodistribution studies were performed in rats with a hepatic somatostatin receptor subtype 2 (sst2)-positive tumor. Clinical study: 3 patients with neuroendocrine liver metastases were injected twice with (111)In-DTPAOC.

Targeted thermosensitive liposomes: an attractive novel approach for increased drug delivery to solid tumors.

Introduction: Currently available chemotherapy is hampered by a lack in tumor specificity and resulting toxicity. Small and long-circulating liposomes can preferentially deliver chemotherapeutic drugs to tumors upon extravasation from tumor vasculature. Although clinically used liposomal formulations demonstrated significant reduction in toxicity, enhancement of therapeutic activity has not fully met expectations.

A novel two-step mild hyperthermia for advanced liposomal chemotherapy.

Liposomal chemotherapy brings the advantage of minimizing systemic toxicity towards healthy organs and tissues, while has the drawbacks of limited nanoparticle accumulation and low drug bioavailability at targeted tumors. The aim of our study is to apply a clinically available mild hyperthermia (HT) treatment with thermosensitive liposomes (TSL) to tackle both issues. A two-step HT approach was combined with systemic administration of doxorubicin (Dox) TSL, in a first step to maximize nanoparticle accumulation in tumors and second step to actively trigger Dox release.

Differential TIMP3 expression affects tumor progression and angiogenesis in melanomas through regulation of directionally persistent endothelial cell migration.

The angiogenic potential of solid tumors, or the ability to initiate neovasculature development from pre-existing host vessels, is facilitated by soluble factors secreted by tumor cells and involves breaching of extracellular matrix barriers, endothelial cell (EC) proliferation, migration and reassembly. We evaluated the angiogenic potential of human melanoma cell lines differing in their degree of aggressiveness, based on their ability to regulate directionally persistent EC migration. We observed that conditioned-medium (CM) of the aggressive melanoma cell line BLM induced a high effective migratory response in ECs, while CMs of Mel57 and 1F6 had an inhibitory effect.