Feasibility of chemohyperthermia with docetaxel-embedded magnetoliposomes as minimally invasive local treatment for cancer

Liposomes for Tumor Targeted Therapy: A Review

Liposomes, the most widely studied nano-drug carriers in drug delivery, are sphere-shaped vesicles consisting of one or more phospholipid bilayers. Compared with traditional drug delivery systems, liposomes exhibit prominent properties that include targeted delivery, high biocompatibility, biodegradability, easy functionalization, low toxicity, improvements in the sustained release of the drug it carries and improved therapeutic indices. In the wake of the rapid development of nanotechnology, the studies of liposome composition have become increasingly extensive. The molecular diversity of liposome composition, which includes long-circulating PEGylated liposomes, ligand-functionalized liposomes, stimuli-responsive liposomes, and advanced cell membrane-coated biomimetic nanocarriers, endows their drug delivery with unique physiological functions. This review describes the composition, types and preparation methods of liposomes, and discusses their targeting strategies in cancer therapy.

The Therapeutic Potential of Chemo/Thermotherapy with Magnetoliposomes for Cancer Treatment

Cancer represents a very grave and quickly growing public health problem worldwide. Despite the breakthroughs in treatment and early detection of the disease, an increase is projected in the incidence rate and mortality during the next 30 years. Thus, it is important to develop new treatment strategies and diagnostic tools. One alternative is magnetic hyperthermia, a therapeutic approach that has shown promising results, both as monotherapy and in combination with chemo- and radiotherapy. However, there are still certain limitations and questions with respect to the safety of the systemic administration of magnetic nanoparticles. To deal with these issues, magnetoliposomes were conceived as a new generation of liposomes that incorporate superparamagnetic nanoparticles and oncological pharmaceuticals within their structure. They have the advantage of targeted and selective drug delivery to the diseased organs and tissues. Some of them can avoid the immune response of the host. When exposed to a magnetic field of alternating current, magnetoliposomes produce hyperthermia, which acts synergistically with the released drug. The aim of the present review is to describe the most recent advances in the use of magnetoliposomes and point out what research remains to be done for their application to chemo-thermal therapy in cancer patients.

Iron Oxide Nanoparticle-Based Hyperthermia as a Treatment Option in Various Gastrointestinal Malignancies

Iron oxide nanoparticle-based hyperthermia is an emerging field in cancer treatment. The hyperthermia is primarily achieved by two differing methods: magnetic fluid hyperthermia and photothermal therapy. In magnetic fluid hyperthermia, the iron oxide nanoparticles are heated by an alternating magnetic field through Brownian and Néel relaxation. In photothermal therapy, the hyperthermia is mainly generated by absorption of light, thereby converting electromagnetic waves into thermal energy. By use of iron oxide nanoparticles, this effect can be enhanced. Both methods are promising tools in cancer treatment and are, therefore, also explored for gastrointestinal malignancies. Here, we provide an extensive literature research on both therapy options for the most common gastrointestinal malignancies (esophageal, gastric and colorectal cancer, colorectal liver metastases, hepatocellular carcinoma, cholangiocellular carcinoma and pancreatic cancer). As many of these rank in the top ten of cancer-related deaths, novel treatment strategies are urgently needed. This review describes the efforts undertaken in vitro and in vivo.

Recent Advancements in Stimuli Responsive Drug Delivery Platforms for Active and Passive Cancer Targeting

The tumor-specific targeting of chemotherapeutic agents for specific necrosis of cancer cells without affecting the normal cells poses a great challenge for researchers and scientists. Though extensive research has been carried out to investigate chemotherapy-based targeted drug delivery, the identification of the most promising strategy capable of bypassing non-specific cytotoxicity is still a major concern. Recent advancements in the arena of onco-targeted therapies have enabled safe and effective tumor-specific localization through stimuli-responsive drug delivery systems. Owing to their promising characteristic features, stimuli-responsive drug delivery platforms have revolutionized the chemotherapy-based treatments with added benefits of enhanced bioavailability and selective cytotoxicity of cancer cells compared to the conventional modalities. The insensitivity of stimuli-responsive drug delivery platforms when exposed to normal cells prevents the release of cytotoxic drugs into the normal cells and therefore alleviates the off-target events associated with chemotherapy. Contrastingly, they showed amplified sensitivity and triggered release of chemotherapeutic payload when internalized into the tumor microenvironment causing maximum cytotoxic responses and the induction of cancer cell necrosis. This review focuses on the physical stimuli-responsive drug delivery systems and chemical stimuli-responsive drug delivery systems for triggered cancer chemotherapy through active and/or passive targeting. Moreover, the review also provided a brief insight into the molecular dynamic simulations associated with stimuli-based tumor targeting.

Molecular targeted treatment and drug delivery system for gastric cancer

Gastric cancer is still a major cancer worldwide. The early diagnosis rate of gastric cancer in most high incidence countries is low. At present, the overall treatment effect of gastric cancer is poor, and the median overall survival remains low. Most of the patients with gastric cancer are in an advanced stage when diagnosed, and drug treatment has become the main means. Thus, new targeted drugs and therapeutic strategies are the hope of improving the therapeutic effect of gastric cancer. In this review, we summarize the new methods and advances of targeted therapy for gastric cancer, including novel molecular targeted therapeutic agents and drug delivery systems, with a major focus on the development of drug delivery systems (drug carriers and targeting peptides). Elaborating these new methods and advances will contribute to the management of gastric cancer.

Nanoparticles guided drug delivery and imaging in gastric cancer

Gastric cancer represents a deadly malignancy worldwide, yet current therapeutic regimens remain ineffective. Nanoparticle (NP) -based solutions could allow the design of novel therapeutic methods to eliminate this fatal disease. NPs typically carry out a significant role in multifunctional, multimodal imaging, and drug delivery carriers. In the recent decade, they have emerged as candidate approaches for the design of novel treatment strategies. Tumor nanotherapeutics characteristically possess various distinct advantages compared to conventional anti-cancer medications, which suffer from nonspecific bio-distribution, low solubility, and poor bioavailability. In this review, we will discuss the application of NPs in diagnosis and controlled drug delivery in gastric cancer (GC). We will focus on various NPs-based strategies employed against GC.

Triggering antitumoural drug release and gene expression by magnetic hyperthermia

Magnetic nanoparticles (MNPs) are promising tools for a wide array of biomedical applications. One of their most outstanding properties is the ability to generate heat when exposed to alternating magnetic fields, usually exploited in magnetic hyperthermia therapy of cancer. In this contribution, we provide a critical review of the use of MNPs and magnetic hyperthermia as drug release and gene expression triggers for cancer therapy. Several strategies for the release of chemotherapeutic drugs from thermo-responsive matrices are discussed, providing representative examples of their application at different levels (from proof of concept to in vivo applications). The potential of magnetic hyperthermia to promote in situ expression of therapeutic genes using vectors that contain heat-responsive promoters is also reviewed in the context of cancer gene therapy.

Liposomes Loaded with Cisplatin and Magnetic Nanoparticles: Physicochemical Characterization, Pharmacokinetics, and In-Vitro Efficacy

With the aim improving drug delivery, liposomes have been employed as carriers for chemotherapeutics achieving promising results; their co-encapsulation with magnetic nanoparticles is evaluated in this work. The objective of this study was to examine the physicochemical characteristics, the pharmacokinetic behaviour, and the efficacy of pegylated liposomes loaded with cisplatin and magnetic nanoparticles (magnetite) (Cis-MLs). Cis-MLs were prepared by a modified reverse-phase evaporation method. To characterize their physicochemical properties, an evaluation was made of particle size, ζ-potential, phospholipid and cholesterol concentration, phase transition temperature (T_m), the encapsulation efficiency of cisplatin and magnetite, and drug release profiles. Additionally, pharmacokinetic studies were conducted on normal Wistar rats, while apoptosis and the cytotoxic effect were assessed with HeLa cells. We present a method for simultaneously encapsulating cisplatin at the core and also embedding magnetite nanoparticles on the membrane of liposomes with a mean vesicular size of 104.4 ± 11.5 nm and a ζ-potential of −40.5 ± 0.8 mV, affording a stable formulation with a safe pharmacokinetic profile. These liposomes elicited a significant effect on cell viability and triggered apoptosis in HeLa cells.

Biocompatibility and therapeutic evaluation of magnetic liposomes designed for self-controlled cancer hyperthermia and chemotherapy

Magnetic liposome-mediated combined chemotherapy and hyperthermia is gaining importance as an effective therapeutic modality for cancer. However, control and maintenance of optimum hyperthermia are major challenges in clinical settings due to the overheating of tissues. To overcome this problem, we developed a novel magnetic liposomes formulation co-entrapping a dextran coated biphasic suspension of La_0.75Sr_0.25MnO₃ (LSMO) and iron oxide (Fe₃O₄) nanoparticles for self-controlled hyperthermia and chemotherapy. However, the general apprehension about biocompatibility and safety of the newly developed formulation needs to be addressed. In this work, in vitro and in vivo biocompatibility and therapeutic evaluation studies of the novel magnetic liposomes are reported. Biocompatibility study of the magnetic liposomes formulation was carried out to evaluate the signs of preliminary systemic toxicity, if any, following intravenous administration of the magnetic liposomes in Swiss mice. Therapeutic efficacy of the magnetic liposomes formulation was evaluated in the fibrosarcoma tumour bearing mouse model. Fibrosarcoma tumour-bearing mice were subjected to hyperthermia following intratumoral injection of single or double doses of the magnetic liposomes with or without chemotherapeutic drug paclitaxel. Hyperthermia (three spurts, each at 3 days interval) with drug loaded magnetic liposomes following single dose administration reduced the growth of tumours by 2.5 fold (mean tumour volume 2356 ± 550 mm³) whereas the double dose treatment reduced the tumour growth by 3.6 fold (mean tumour volume 1045 ± 440 mm³) compared to their corresponding control (mean tumour volume 3782 ± 515 mm³). At the end of the tumour efficacy studies, the presence of MNPs was studied in the remnant tumour tissues and vital organs of the mice. No significant leaching or drainage of the magnetic liposomes during the study was observed from the tumour site to the other vital organs of the body, suggesting again the potential of the novel magnetic liposomes formulation for possibility of developing as an effective modality for treatment of drug resistant or physiologically vulnerable cancer.

Drug releasing nanoplatforms activated by alternating magnetic fields

The use of an alternating magnetic field (AMF) to generate non-invasively and spatially a localized heating from a magnetic nano-mediator has become very popular these last years to develop magnetic hyperthermia (MH) as a promising therapeutic modality already used in the clinics. AMF has become highly attractive this last decade over others radiations, as AMF allows a deeper penetration in the body and a less harmful ionizing effect. In addition to pure MH which induces tumor cell death through local T elevation, this AMF-generated magneto-thermal effect can also be exploited as a relevant external stimulus to trigger a drug release from drug-loaded magnetic nanocarriers, temporally and spatially. This review article is focused especially on this concept of AMF induced drug release, possibly combined with MH. The design of such magnetically responsive drug delivery nanoplatforms requires two key and complementary components: a magnetic mediator which collects and turns the magnetic energy into local heat, and a thermoresponsive carrier ensuring thermo-induced drug release, as a consequence of magnetic stimulus. A wide panel of magnetic nanomaterials/chemistries and processes are currently developed to achieve such nanoplatforms. This review article presents a broad overview about the fundamental concepts of drug releasing nanoplatforms activated by AMF, their formulations, and their efficiency in vitro and in vivo. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editors: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.

Integrin α3 is overexpressed in glioma stem-like cells and promotes invasion

Background:

Glioma stem-like cell (GSC) properties are responsible for gliomagenesis and recurrence. GSCs are invasive but its mechanism remains to be elucidated. Here, we attempted to identify the molecules that promote invasion in GSCs.

Methods:

Neurospheres and CD133⁺ cells were collected from glioblastoma (GBM) specimens and glioma cell lines by sphere-formation method and magnetic affinity cell sorting, respectively. Differential expression of gene candidates, its role in invasion and its signaling pathway were evaluated in glioma cell lines.

Results:

Neurospheres from surgical specimens attached to fibronectin and laminin, the receptors of which belong to the integrin family. Integrin α3 was overexpressed in CD133⁺ cells compared with CD133⁻ cells in all the glioma cell lines (4 out of 4). Immunohistochemistry demonstrated the localisation of integrin α3 in GBM cells, including invading cells, and in the tumour cells around the vessels, which is believed to be a stem cell niche. The expression of integrin α3 was correlated with migration and invasion. The invasion activity of glioma cells was linked to the phosphorylation of extracellular signal–regulated kinase (ERK) 1/2.

Conclusion:

Our results suggest that integrin α3 contributes to the invasive nature of GSCs via ERK1/2, which renders integrin α3 a prime candidate for anti-invasion therapy for GBM.

Application of liposomes in drug development--focus on gastroenterological targets

Over the past decade, liposomes became a focal point in developing drug delivery systems. New liposomes, with novel lipid molecules or conjugates, and new formulations opened possibilities for safely and efficiently treating many diseases including cancers. New types of liposomes can prolong circulation time or specifically deliver drugs to therapeutic targets. This article concentrates on current developments in liposome based drug delivery systems for treating diseases of the gastrointestinal tract. We will review different types and uses of liposomes in the development of therapeutics for gastrointestinal diseases including inflammatory bowel diseases and colorectal cancer.

Dual effects of daily FTY720 on human astrocytes in vitro: relevance for neuroinflammation

Background

FTY720 (fingolimod, Gilenya™) is a daily oral therapy for multiple sclerosis that readily accesses the central nervous system (CNS). FTY720 is a structural analog to the sphingolipid sphingosine-1-phosphate (S1P) and is a cognate ligand for the S1P G-protein coupled receptors (S1PR). Studies in experimental autoimmune encephalomyelitis using mice with conditionally deleted S1P₁R from astrocytes indicate that one beneficial effect of FTY720 in this model is via downregulating external receptors, which inhibits responses induced by the natural ligand. Another proposed effect of FTY720 on neuroinflammation is its ability to maintain persistent signaling in cells via internalized S1P₁R resulting in functional responses that include suppressing intracellular calcium release. We used human fetal astrocytes to investigate potential dual inhibitory- and function-inducing effects of daily FTY720 on responses relevant to neuroinflammation. For the inhibitory effects, we used signaling and proliferation induced by the natural ligand S1P. For the function-inducing responses, we measured inhibition of intracellular calcium release stimulated by the proinflammatory cytokine, interleukin (IL)-1β.

Methods

Astrocytes derived from human fetal CNS specimens and maintained in dissociated cultures were exposed to 100 nM of the biologically active form of FTY720 over a dosing regimen that ranged from a single exposure (with or without washout after 1 h) to daily exposures up to 5 days. Responses measured include: phosphorylation of extracellular-signal-regulated kinases (pERK1/2) by Western blotting, Ki-67 immunolabeling for cell proliferation, IL-1β-induced calcium release by ratiometric fluorescence, and cytokine/chemokine (IL-6, CXCL10) secretions by ELISA.

Results

We observed that a single addition of FTY720 inhibited subsequent S1PR ligand-induced pERK1/2 signaling for >24 h. Daily FTY720 treatments (3-5 days) maintained this effect together with a loss of proliferative responses to the natural ligand S1P. Repeated FTY720 dosing concurrently maintained a functional cell response as measured by the inhibition of intracellular calcium release when stimulated by the cytokine IL-1β. Recurrent FTY720 treatments did not inhibit serum- or IL-1β-induced pERK1/2. The secretions of IL-6 and CXCL10 in response to IL-1β were unaffected by FTY720 treatment(s).

Conclusion

Our results indicate that daily FTY720 exposures may regulate specific neuroinflammatory responses by desensitizing astrocytes to external S1PR stimuli while sustaining cellular influences that are independent of new surface S1PR activation.

Tumor local chemohyperthermia using docetaxel-embedded magnetoliposomes: Interaction of chemotherapy and hyperthermia

BACKGROUND AND AIM

We have studied and reported the usefulness of tumor local chemohyperthermia at a low-grade temperature below 43°C with docetaxel-embedded magnetoliposome (DML) and an applied alternating current magnetic field. However, the mechanisms of this treatment and the dynamics of the injected docetaxel were not investigated in our previous study. Thus, we investigated the interaction of chemotherapy and hyperthermia in the treated tumor.

METHODS

Human MKN45 gastric cancer cells were implanted in the hind limbs of Balb-c/nu/nu mice. DML, magnetite-loaded liposome, and docetaxel were injected into the tumors with or without being exposed to an alternating current magnetic field. Docetaxel and tumor necrosis factor-α concentrations, the cell cycle, and cell death rates in the tumor were examined.

RESULTS

Docetaxel concentrations were significantly higher in the DML-injected group than in the docetaxel-injected group 3 days after injection. A G2/M peak was observed 1 day after treatment in the DML-injected and exposed group and the docetaxel-injected group, while it was observed 3 days after treatment in the DML-injected without heating group and the magnetite-loaded liposome group. The tumor cell death rate gradually increased in the DML-injected group, with or without being exposed, while it gradually decreased after its peak in other groups. The tumor necrosis factor-α concentration in the tumor treated with DML with heating remained at a high level on the 7th day after treatment, while it decreased after its peak in other groups.

CONCLUSION

The antitumor effect of this treatment derives from a combination of hyperthermia and chemotherapy locally in the tumor.

Effects of lysophospholipids on tumor microenvironment

The effects of lysophospholipids (LPLs) on cancer microenvironment is a vast and growing field. These lipids are secreted physiologically by various cell types. They play highly important roles in the development, activation and regulation of the immune system. They are also secreted by cancerous cells and there is a strong association between LPLs and cancer. It is clear that these lipids and in particular sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) play major roles in regulating the growth of tumor cells, and in manipulating the immune system. These activities can be divided into two parts; the first involves the ability of S1P and LPA to either directly or through some of the enzymes that generate them such as sphingosine kinases or phospholipases, induce the motility and invasiveness of tumor cells. The second mechanism involves the recently discovered effects of these lipids on the anti-tumor effector natural killer (NK) cells. Whereas S1P and LPA induce the recruitment of these effector cells, they also inhibit their cytolysis of tumor cells. This may support the environment of cancer and the ability of cancer cells to grow, spread and metastasize. Consequently, LPLs or their receptors may be attractive targets for developing drugs in the treatment of cancer where LPLs or their receptors are up-regulated.

Epithelioid glioblastoma changed to typical glioblastoma: the methylation status of MGMT promoter and 5-ALA fluorescence

A 55-year-old man was admitted to our hospital complaining of left hemiparesis. Magnetic resonance imaging (MRI) showed a smooth ring-like enhanced cystic tumor in the right parietal lobe. He underwent gross total resection of the tumor under neuronavigation and 5-aminolevulinic acid (5-ALA) fluorescence guiding method. Histopathological examination of the tumor showed small cells formed epithelioid solid nests with some focus of duct-like structure. On the basis of the MRI and operative and histological findings, this tumor was diagnosed as a metastatic poorly differentiated carcinoma, although the primary cancer could not be detected by metastatic work-ups. Afterward, this tumor recurred repeatedly. Histopathological examination of specimen from the fourth surgery indicated that the tumor was a glioblastoma (GBM). In the review of the histology and immunohistochemistry of the first tumor, atypical fibrillary cells were seen between solid nests and positive for glial fibrillary acidic protein, therefore the tumor was retrospectively diagnosed as epithelioid GBM. We assessed whether the changes in histopathology were accompanied by changes in the methylation status of O6-methylguanine methyltransferase (MGMT) promoter and the status of 5-ALA fluorescence. The methylation status of the MGMT promoter was found to have changed from methylated to unmethylated and 5-ALA fluorescence became positive along with the histological change.

Sphingosine 1-phosphate and cancer

There is substantial evidence that sphingosine 1-phosphate (S1P) is involved in cancer. S1P regulates processes such as inflammation, which can drive tumorigenesis; neovascularization, which provides cancer cells with nutrients and oxygen; and cell growth and survival. This occurs at multiple levels and involves S1P receptors, sphingosine kinases, S1P phosphatases and S1P lyase. This Review summarizes current research findings and examines the potential for new therapeutics designed to alter S1P signalling and function in cancer.