Palmitic acid induces intestinal lipid metabolism disorder, endoplasmic reticulum stress and inflammation by affecting phosphatidylethanolamine content in large yellow croaker Larimichthys crocea.

In the 21st century, intestinal homeostatic imbalance has emerged as a growing health challenge worldwide. Accumulating evidence reveals that excessive intake of saturated fatty acid (SFA) induces intestinal homeostatic imbalance. However, the potential molecular mechanism is still unclear. In the present study, we found that palm oil or palmitic acid (PA) treatment disturbed lipid metabolism homeostasis and triggered endoplasmic reticulum (ER) stress and inflammation in the intestine or intestinal cells of large yellow croaker (Larimichthys crocea). Interestingly, PA treatment significantly decreased phosphatidylethanolamine (PE) content in the intestinal cells. PE supplementation decreased triglyceride content in the intestinal cells induced by PA treatment by inhibiting fatty acid uptake and lipogenesis. PE supplementation suppressed ER stress. Meanwhile, PE supplementation alleviated inflammatory response through p38 MAPK-p65 pathway, reducing the damage of intestinal cells caused by PA treatment to some extent. Our work revealed that intestinal homeostatic imbalance caused by PA treatment was partly due to the decrease of PE content. PE consumption might be a nutritional strategy to regulate intestinal homeostasis in fish and even human beings.

Effectiveness and safety of 1L PEG-ASC preparation for colonoscopy in patients with inflammatory bowel diseases.

INTRODUCTION: The effectiveness of bowel cleansing is a key element for high-quality colonoscopy. Recently, a 1 L polyethylene glycol plus ascorbate (PEG-ASC) solution has been introduced, but effectiveness and safety of this preparation have not been assessed in IBD patients. This study aims to evaluate effectiveness and safety of 1 L PEG-ASC solution in patients with IBD compared to controls. METHODS: We retrospectively analysed prospectively collected data on a cohort of 411 patients performing a colonoscopy after preparation with 1 L PEG-ASC, consecutively enrolled in 5 Italian centres. RESULTS: Overall, 185/411 (45%) were patients with IBD and 226/411 (55%) served as controls. A significantly higher cleansing success was achieved in IBD patients (92.9% vs 85.4%, p = 0.02). The multiple regression model showed that presence of IBD (OR=2.514, 95%CI=1.165-5.426; P = 0.019), lower age (OR=0.981, 95%CI=0.967-0.996; P = 0.014), split preparation (OR=2.430, 95%CI=1.076-5.492; P = 0.033), absence of diabetes (OR=2.848, 95%CI=1.228-6.605; P = 0.015), and of chronic constipation (OR=3.350, 95%CI=1.429-7.852; P = 0.005), were independently associated with cleansing success. The number of treatment-emergent adverse events (TEAEs) (51 vs 62%, p = 0.821), and of patients with TEAEs (22.2% vs 21.2%, p = 0.821), were similar in IBD patients and in controls, respectively. CONCLUSIONS: Results from this study support the effectiveness and safety of 1 L PEG-ASC solution in IBD patients, which may improve the definition of endoscopic outcomes both in Crohn's disease and ulcerative colitis.

Muramyl Tripeptide Plus Chemotherapy Reduces Metastasis in Non-Metastatic Osteosarcoma: A Single-Center Experience.

BACKGROUND: The immunomodulator mifamurtide plus a chemotherapy regimen has been shown to significantly improve the outcome in non-metastatic osteosarcoma patients. We report the results of the addition of mifamurtide to chemotherapy in newly diagnosed patients with osteosarcoma. METHODS: A total of 36 children with osteosarcoma without detectable metastasis were treated between November 2010 and April 2018 at the Ankara University Department of Pediatric Oncology. Mifamurtide was added to the chemotherapy regimen in 17 patients while the remaining 19 did not receive mifamurtide. The probabilities of metastasis and overall survival were compared between the groups. RESULTS: The 43-month survival rate was 87.5% and 89.9% in the patients who received and did not receive mifamurtide, respectively (p=0.65). Common side effects of mifamurtide were chills and fever. The addition of mifamurtide in the high-risk group with ≤95% necrosis tended to decrease the probability of distant metastasis (36.4% vs. 58.3%) (p=0.39). The time to metastasis in the group with positive surgical margins (4 months in one patient in the non-mifamurtide group, 7 and 20 months in the mifamurtide group) was also longer in the mifamurtide group. During the 43-month follow up period, median time to metastasis was longer in the mifamurtide group (20 vs. 5 months). In addition, mifamurtide plus chemotherapy decreased the risk of metastasis in the cases with primary site relapse. CONCLUSIONS: The addition of mifamurtide to chemotherapy might improve event-free survival by decreasing the probability of distant metastasis in bad histologic responders, and also by increasing the time to distant metastasis in the surgical margin positive group. Additional clinical studies are necessary to determine the long-term effects of mifamurtide on metastatic disease.
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Gadolinium labelled nanoliposomes as the platform for MRI theranostics: in vitro safety study in liver cells and macrophages.

Gadolinium (Gd)-based contrast agents are extensively used for magnetic resonance imaging (MRI). Liposomes are potential nanocarrier-based biocompatible platforms for development of new generations of MRI diagnostics. Liposomes with Gd-complexes (Gd-lip) co-encapsulated with thrombolytic agents can serve both for imaging and treatment of various pathological states including stroke. In this study, we evaluated nanosafety of Gd-lip containing PE-DTPA chelating Gd+3 prepared by lipid film hydration method. We detected no cytotoxicity of Gd-lip in human liver cells including cancer HepG2, progenitor (non-differentiated) HepaRG, and differentiated HepaRG cells. Furthermore, no potential side effects of Gd-lip were found using a complex system including general biomarkers of toxicity, such as induction of early response genes, oxidative, heat shock and endoplasmic reticulum stress, DNA damage responses, induction of xenobiotic metabolizing enzymes, and changes in sphingolipid metabolism in differentiated HepaRG. Moreover, Gd-lip did not show pro-inflammatory effects, as assessed in an assay based on activation of inflammasome NLRP3 in a model of human macrophages, and release of eicosanoids from HepaRG cells. In conclusion, this in vitro study indicates potential in vivo safety of Gd-lip with respect to hepatotoxicity and immunopathology caused by inflammation.

3,5,4'-trimethoxy-trans-stilbene loaded PEG-PE micelles for the treatment of colon cancer.

BACKGROUND: 3,5,4'-trimethoxy-trans-stilbene (BTM) is a methylated derivative of resveratrol. To improve the pharmaceutical properties of BTM, BTM loaded PEG-PE micelles (BTM@PEG-PE) were fabricated and its anti-cancer efficacy against colon cancer was evaluated. METHODS: BTM@PEG-PE micelles were prepared by the solvent evaporation method and were characterized by nuclear magnetic resonance (NMR), size, zeta potential, polymer disperse index (PDI) and transmission electron microscopy (TEM). Cellular uptake, cell viability assay, caspase-3 activity assay and flow cytometry were performed to evaluate the cell internalization and anti-cancer efficacy of BTM@PEG-PE micelles in vitro. Pharmacokinetic profiles of BTM and BTM@PEG-PE micelles were compared and in vivo anti-cancer therapeutic efficacy and safety of BTM@PEG-PE micelles on CT26 xenograft mice were evaluated. RESULTS: BTM was successfully embedded in the core of PEG-PE micelles, with a drug loading capacity of 5.62±0.80%. PEG-PE micelles facilitated BTM entering to the CT26 cells and BTM@PEG-PE micelles exerted enhanced anti-cancer efficacy against CT26 cells. BTM@PEG-PE micelles showed prolonged half-life and increased bioavailability. More importantly, BTM@PEG-PE micelles treatment suppressed tumor growth in tumor-bearing mice and prolonged survival with minimal damage to normal tissues. CONCLUSION: Altogether, the BTM@PEG-PE micelles might be a promising strategy to enhance the pharmacokinetic and pharmacodynamic potentials of BTM for colon cancer therapy.

The Efficiency and Toxicity of Mifamurtide in Childhood Osteosarcoma.

The aim of the present study was to evaluate the efficiency and side effects of mifamurtide in childhood osteosarcoma (OS). In total, 477 doses of 2 mg/m intravenous (IV) mifamurtide, along with paracetamol as a premedication, were given to 15 patients with primary nonmetastatic OS after complete surgical resection and to 3 patients with progressive OS. The most common side effects encountered in the patients were chills and fever (17/18). These reactions were observed in 4 patients during the administration of each dose, in a single patient during the last administration, and in the remaining 12 patients during the first or initial 2 administrations. Headache, myalgia, and arthralgia were observed in 2 patients during each infusion. Headache was observed in 1 patient with additional hearing loss during the first 2 infusions. One patient had back pain occuring within the first infusion. Of the 15 patients with primary nonmetastatic OS and treated with the addition of mifamurtide to chemotherapy, 13 showed a complete remission, and 2 patients were still under treatment with a complete remission. Of 3 patients with progressive disease, 2 died while the disease progressed further in the third case over a 51-month period. The 3-year overall survival and event-free survival distributions were 87.5% (mean follow-up time, 46.12; 95% confidence interval, 37.79-52.45 mo) and 75.6% (mean follow-up time, 31.30; 95% confidence interval, 26.54-36.06 mo), respectively. We consider that mifamurtide therapy is a safe and well-tolerated agent in childhood OS.

Investigations on clonazepam-loaded polymeric micelle-like nanoparticles for safe drug administration during pregnancy.

Medication during pregnancy is often a necessity for women to treat their acute or chronic diseases. The goal of this study is to evaluate the potential of micelle-like nanoparticles (MNP) for providing safe drug usage in pregnancy and protect both foetus and mother from medication side effects. Clonazepam-loaded MNP were prepared from copolymers [polystyrene-poly(acrylic acid) (PS-PAA), poly(ethylene glycol)-b-poly(lactic acid) (PEG-PLA) and distearyl-sn-glycero-3-phosphoethanolamine-N-[methoxy-poly(ethylene glycol) (PEG-DSPE)] with varying monomer ratios and their drug-loading efficiency, drug release ratio, particle size, surface charge and morphology were characterised. The cellular transport and cytotoxicity experiments were conducted on clonazepam and MNP formulations using placenta-choriocarcinoma-BeWo and brain-endothelial-bEnd3 cells. Clonazepam-loaded PEG5000-PLA4500 MNP reduced the drug transport through BeWo cells demonstrating that MNP may lower foetal drug exposure, thus reduce the drug side effects. However, lipofectamine modified MNP improved the transport of clonazepam and found to be promising for brain and in-utero-specific drug treatment.

Preclinical Pharmacology and Pharmacokinetics of Inhaled Hexadecyl-Treprostinil (C16TR), a Pulmonary Vasodilator Prodrug.

This article describes the preclinical pharmacology and pharmacokinetics (PK) of hexadecyl-treprostinil (C16TR), a prodrug of treprostinil (TRE), formulated in a lipid nanoparticle (LNP) for inhalation as a pulmonary vasodilator. C16TR showed no activity (>10 µM) in receptor binding and enzyme inhibition assays, including binding to prostaglandin E2 receptor 2, prostaglandin D2 receptor 1, prostaglandin I2 receptor, and prostaglandin E2 receptor 4; TRE potently bound to each of these prostanoid receptors. C16TR had no effect (up to 200 nM) on platelet aggregation induced by ADP in rat blood. In hypoxia-challenged rats, inhaled C16TR-LNP produced dose-dependent (0.06-6 µg/kg), sustained pulmonary vasodilation over 3 hours; inhaled TRE (6 µg/kg) was active at earlier times but lost its effect by 3 hours. Single- and multiple-dose PK studies of inhaled C16TR-LNP in rats showed proportionate dose-dependent increases in TRE Cmax and area under the curve (AUC) for both plasma and lung; similar results were observed for dog plasma levels in single-dose PK studies. In both species, inhaled C16TR-LNP yielded prolonged plasma TRE levels and a lower plasma TRE Cmax compared with inhaled TRE. Inhaled C16TR-LNP was well tolerated in rats and dogs; TRE-related side effects included cough, respiratory tract irritation, and emesis and were seen only after high inhaled doses of C16TR-LNP in dogs. In guinea pigs, inhaled TRE (30 µg/ml) consistently produced cough, but C16TR-LNP (30 µg/ml) elicited no effect. These results demonstrate that C16TR-LNP provides long-acting pulmonary vasodilation, is well tolerated in animal studies, and may necessitate less frequent dosing than inhaled TRE with possibly fewer side effects.

Mannosylated solid lipid nanoparticles for lung-targeted delivery of Paclitaxel.

OBJECTIVE: The present study discusses paclitaxel (PTX)-loaded mannosylated-DSPE (Distearoyl-phosphatidyl-ethanolamine) solid lipid nanoparticles (M-SLNs) using mannose as a lectin receptor ligand conjugate for lung cancer targeting and to increase the anticancer activity of PTX against A549 lung's epithelial cancer cells. MATERIALS AND METHODS: The PTX-SLNs were prepared by solvent injection method and mannose was conjugated to the free amine group of stearylamine. The M-SLNs obtained were characterized for their particle size, polydispersity index, zeta potential and morphology by transmission electron microscope. RESULTS: The M-SLNs were spherical in shape with 254 ± 2.3 nm average size, positive zeta potential (3.27 mV), 79.4 ± 1.6 drug entrapment efficiency and showed the lower extent of drug release 40% over 48 h in vitro. Cytotoxicity study on A549 cell lines and biodistrubtion study of drug revealed that M-SLNs deliver a higher concentration of PTX as compared to PTX-SLNs in an alveolar cell site. DISCUSSION AND CONCLUSION: These results suggested that mannosylated M-SLNs are safe and potential vector for lung cancer targeting.

Pharmacokinetics and pharmacodynamics of liposomal mifamurtide in adult volunteers with mild or moderate hepatic impairment.

AIMS: To evaluate the pharmacokinetics and pharmacodynamics after a single dose of liposomal mifamurtide (liposomal muramyl tripeptide phospatidyl ethanolamine; MEPACT(®)) in adult subjects with mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment in comparison with age-, weight- and sex-matched healthy subjects with normal hepatic function. METHODS: Subjects received a 4 mg dose of liposomal mifamurtide via 1 h intravenous infusion. Blood samples were collected over 72 h for pharmacokinetic and pharmacodynamic assessments (changes in serum interleukin-6, tumour necrosis factor-α and C-reactive protein). RESULTS: Thirty-seven subjects were enrolled: nine with mild hepatic impairment, eight with moderate hepatic impairment and 20 matched healthy subjects. Geometric least-square mean ratios of total mifamurtide AUCinf for the mild hepatic impairment and moderate hepatic impairment groups vs. matched healthy subjects were 105% (90% confidence interval, 83.6-132%) and 119% (90% confidence interval, 94.1-151%), respectively, which are below the protocol-specified threshold (150%) to require development of dose-modification recommendations. Pharmacodynamic parameters for changes in serum interleukin-6 and tumour necrosis factor-α concentrations were generally similar across hepatic function groups. Mifamurtide-induced increases in serum C-reactive protein were attenuated in the moderate hepatic impairment group, consistent with the liver being the major organ of C-reactive protein synthesis. No grade ≥3 adverse events were seen in subjects administered mifamurtide (4 mg). CONCLUSIONS: These results support the conclusion that mild or moderate hepatic impairment does not produce clinically meaningful effects on the clinical pharmacokinetics or pharmacodynamics of mifamurtide; no dose modifications are needed in these special patient populations based on clinical pharmacological considerations.

A dengue DNA vaccine formulated with Vaxfectin® is well tolerated, and elicits strong neutralizing antibody responses to all four dengue serotypes in New Zealand white rabbits.

A tetravalent DNA vaccine formulated with Vaxfectin adjuvant was shown to elicit high levels of neutralizing antibody against all four dengue virus serotypes (Porter et al., ( 16) ), warranting further testing in humans. In preparation for a phase 1 clinical testing, the vaccine and the adjuvant were manufactured under current good manufacturing practice guidelines. The formulated vaccine and the adjuvant were tested for safety and/or immunogenicity in New Zealand white rabbits using a repeat dose toxicology study. The formulated vaccine and the adjuvant were found to be well tolerated by the animals. Animals injected with formulated vaccine produced strong neutralizing antibody response to all four dengue serotypes.

A pharmacokinetic, pharmacodynamic, and electrocardiographic study of liposomal mifamurtide (L-MTP-PE) in healthy adult volunteers.

PURPOSE: This study evaluated the pharmacokinetics (PK), pharmacodynamics (PD), safety/tolerability, and cardiac safety of liposomal muramyl tripeptide phosphatidyl-ethanolamine [mifamurtide (L-MTP-PE)] in healthy adults. METHODS: L-MTP-PE 4 mg was administered intravenously over 30 min. Study participants were monitored from 24 h preinfusion until 72 h postinfusion. Blood samples were drawn over 0-72 h postdose to determine serum MTP-PE, interleukin (IL)-6, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP) concentrations. Electrocardiograpic (ECG) data were collected via continuous Holter monitoring beginning 24 h predose through 24 h postdose. Changes from time-matched pretreatment baseline QTc and associated two-sided 90 % confidence intervals were calculated. RESULTS: Twenty-one participants received L-MTP-PE. Total serum MTP-PE declined rapidly with a terminal half-life of 2.05 ± 0.40 h. PK variability was low, with <30 % coefficient of variation in systemic exposure. Serum concentrations of IL-6, TNF-α, and CRP increased following L-MTP-PE infusion. Maximum observed increases in IL-6 and TNF-α occurred at 4 and 2 h, respectively, returning toward baseline by 8 h postdose. L-MTP-PE was generally well tolerated, with no adverse events greater than grade 3. Headache, chills, tachycardia, nausea, and pyrexia were the most frequent adverse events. L-MTP-PE infusion resulted in an increased heart rate without readily apparent QTc prolongation. CONCLUSIONS: MTP-PE PK following L-MTP-PE administration were characterized by a short serum half-life and low variability. Increases in IL-6, TNF-α, and CRP and the safety profile were consistent with the immunomodulatory mechanism of action. No clinically significant effect of L-MTP-PE on cardiovascular repolarization was observed based on analysis of ECG QTc intervals.

Liposomal topotecan formulation with a low polyethylene glycol grafting density: pharmacokinetics and antitumour activity.

OBJECTIVES: PEGylated liposomes could evade recognition by the reticulo-endothelial system and prolong the circulation time of vesicles, resulting in enhanced targeting efficiency and antitumour effect. Typically, vesicles are modified with distearoylphosphatidylethanolamine (DSPE)-polyethylene glycol (PEG) at a high PEG grafting density. However, long circulation time and slow drug release rate might induce severe hand-foot syndrome in clinical practice. In this study, a liposomal topotecan formulation with a low PEG grafting density was prepared and its pharmacokinetics, acute toxicity and antitumour effect were investigated. METHODS: Topotecan was loaded into liposomes using an ammonium sulfate gradient. The resulting formulation was injected to healthy Wistar rats at different dose levels to investigate whether its clearance followed linear kinetics. Biodistribution was performed in Lewis lung cancer-bearing mice. The acute toxicity was evaluated in healthy mice and beagle dogs. To compare the antitumour effects of different formulations and dose schedule, RM-1 prostate, Lewis lung, H446 and L1210 cancer models were used. KEY FINDINGS: Topotecan could be encapsulated into low DSPE-PEG liposomes with ∼100% loading efficiency. The clearance of the liposomal formulation followed linear kinetics at a dose level ranging from 0.5 to 4 mg/kg despite the fact that the vesicles were coated at a low PEG density. Compared with free topotecan the liposomal formulation preferentially accumulated into tumour zones instead of normal tissues. Both formulations could rapidly accumulate into liver and tumour, but the liposomal formulation was cleared from tissues at a slow rate relative to the conventional formulation. In rats and beagle dogs, liposomal formulations could not induce skin toxicity. In all the tumour models, smaller split doses were more therapeutically active than larger doses when the overall dose intensity was equivalent. CONCLUSIONS: This has been the first report that plasma kinetics of a liposomal formulation with a low PEG density followed linear kinetics. Moreover, due to its short circulation half-life, the formulation did not induce skin toxicity. Our data revealed that the dose schedule of liposomal drugs should be adjusted in accordance with the biophysical and biological properties of the formulations to achieve the optimal therapeutic efficacy.

Mifamurtide: osteosarcoma: ineffective and harmful.

The standard treatment for children and young adults with osteosarcoma consists of surgery, preceded and followed by methotrexate-based chemotherapy. Mifamurtide is an immunostimulant derived from a bacterial cell wall component. It is authorised in the European Union as an adjunct to combination chemotherapy after complete excision of non-metastatic osteosarcoma. Only one comparative, unblinded trial has been published, and its design was particularly complex. In a study population of 678 patients, adding mifamurtide to chemotherapy after tumour excision did not prolong the overall 6-year survival rate, which was about 75% with both treatments. Only serious adverse effects were collected, and they were not systematically recorded. Hypersensitivity reactions occurred in clinical trials, along with pleural and pericardial effusions, seizures, and muscle spasms. Severe hearing loss occurred in 12% of the patients treated with mifamurtide in the comparative trial, versus 7% of the other patients. In practice, given the lack of any survival benefit and the risk of serious adverse effects, it is better not to add mifamurtide to chemotherapy regimens used for treatment of osteosarcoma.

Nonclinical biodistribution, integration, and toxicology evaluations of an H5N1 pandemic influenza plasmid DNA vaccine formulated with Vaxfectin®.

Vaxfectin(®) is a lipid-based adjuvant initially developed for use with plasmid DNA (pDNA) vaccines. Here we present detailed nonclinical assessments performed prior to Vaxfectin(®)'s first-in-man use, as an adjuvant in the H5N1 influenza vaccine VCL-IPT1. Following IM delivery to rabbits, VCL-IPT1 pDNA localized primarily to injection sites, where levels steadily declined over the 2 months examined. Risk of pDNA integration into genomic DNA was negligible. Toxicology studies in rabbits revealed mild inflammatory/immune responses at injection sites characteristic of IM vaccine delivery; Vaxfectin(®) directly contributed to these responses. These data support clinical development of H5N1 pDNA vaccines, and also present an encouraging profile for further development of Vaxfectin(®) as an adjuvant for vaccines in general.

Mifamurtide for the treatment of nonmetastatic osteosarcoma.

INTRODUCTION: The standard treatment for osteosarcoma requires both macroscopic surgical wide resection and postoperative multi-drug chemotherapy in neoadjuvant and adjuvant settings. However, the 5-year event-free survival has remained at a plateau of 60-70% of patients with nonmetastatic osteosarcoma for more than 30 years. AREAS COVERED: Mifamurtide (liposomal muramyl tripeptide phosphatidylethanolamine; L-MTP-PE) is a new agent. L-MTP-PE is a nonspecific immunomodulator, which is a synthetic analog of a component of bacterial cell walls. L-MTP-PE activates macrophages and monocytes as a potent activator of immune response in addition to standard chemotherapy. It also improves the overall survival from 70 to 78% and results in a one-third reduction in the risk of death from osteosarcoma. This review summarizes the most recent findings about L-MTP-PE and its therapeutic application for nonmetastatic osteosarcoma. EXPERT OPINION: Recently, L-MTP-PE has been approved in Europe for the treatment of nonmetastatic osteosarcoma with chemotherapy. L-MTP-PE in combination with traditional treatment is expected to go mainstream and to be beneficial for patients with osteosarcoma. Information about potential benefit regarding mifamurtide use in the neoadjuvant setting (i.e., before surgery) and/or usefulness of L-MTP-PE in metastatic in relapsed and metastatic osteosarcoma requires analysis of expanded access and/or future clinical trials of L-MTP-PE in high-burden and low-burden situations.

Vaxfectin: a versatile adjuvant for plasmid DNA- and protein-based vaccines.

IMPORTANCE OF THE FIELD: Many vaccines require the use of an adjuvant to achieve immunity. So far, few adjuvants have advanced successfully through clinical trials to become part of licensed vaccines. Vaxfectin® (Vical, CA, USA) represents a next-generation adjuvant with promise as a platform technology, showing utility with both plasmid DNA (pDNA) and protein-based vaccines. AREAS COVERED IN THIS REVIEW: This review describes the chemical, physical, preclinical and clinical development of Vaxfectin for pDNA-based vaccines. Also included is the preclinical development of Vaxfectin-adjuvanted protein- and peptide-based vaccines. WHAT THE READER WILL GAIN: The reader will gain knowledge of vaccine adjuvant development from bench to bedside. TAKE HOME MESSAGE: Vaxfectin has effectively boosted the immune response against a range of pDNA-expressed pathogenic antigens in preclinical models extending from rodents to non-human primates. In the clinic, Vaxfectin-adjuvanted pDNA-based H5N1 influenza vaccines have been shown to be well tolerated and to result in durable immune responses within the predicted protective range reported for protein-based vaccines.

Mifamurtide in osteosarcoma--a practical review.

Mifamurtide, also known as liposomal muramyl tripeptide phosphatidyl ethanolamine (L-MTP-PE), has been approved for the treatment of osteosarcoma in Europe. Mifamurtide's rational drug design employs MTP-PE for macrophage activation in a multilamellar liposome drug carrier, containing the synthetic phospholipids 1-palmitoyl-2-oleoyl phosphatidyl choline (POPC) and 1,2-dioleoyl phosphatidyl serine (OOPS). Although the drug is not cytotoxic towards normal or tumor cells in vitro, immune activation against osteosarcoma lung metastases in vivo accounts for mifamurtide's antiosteosarcoma effects. Phosphatidyl serine-containing lipids signal macrophage cells that have "flipped phosphatidyl serine" to the outer membrane after apoptosis (e.g., after damage of tumor cells from chemotherapy); thus, both mifamurtide's active and inactive ingredients target immune cells in the lungs. Mifamurtide administration has resulted in 8% and 13% improvement in 6- and 5-year overall survivals, when added to chemotherapy in nonmetastatic and metastatic patients with osteosarcoma, respectively. The short-term toxicities of mifamurtide (fever, headache, flu-like symptoms and rigors) are reduced or eliminated using ibuprofen (200 mg) as premedication for the first infusion; an algorithm for pre- and postmedication is presented. To date, no long-term side effects of mifamurtide have been reported. Compassionate access programs based in two major cancer centers (MD Anderson and Memorial Sloan-Kettering), have recently provided this potentially life-saving drug in North America. The experience with mifamurtide provides an outstanding example of successful cooperation among regulatory bodies and agencies, the pharmaceutical industry and pediatric oncologists to improve cancer care and outcomes for children and young people with a rare sarcoma.

Mifamurtide: a review of its use in the treatment of osteosarcoma.

Mifamurtide (liposomal muramyl tripeptide phosphatidyl ethanolamine; Mepact) is an immunomodulator with antitumor effects that appear to be mediated via activation of monocytes and macrophages. In the EU, mifamurtide is indicated in children, adolescents, and young adults for the treatment of high-grade, resectable, non-metastatic osteosarcoma after macroscopically complete surgical resection; it is administered by intravenous infusion in conjunction with postoperative multiagent chemotherapy. In the US, mifamurtide is currently an investigational agent that holds orphan drug status for the treatment of osteosarcoma. In a large, randomized, open-label, multicenter, phase III trial, the addition of adjuvant (postoperative) mifamurtide to three- or four-drug combination chemotherapy (doxorubicin, cisplatin, and high-dose methotrexate with, or without, ifosfamide) was associated with a statistically significant improvement in overall survival in patients with newly diagnosed, high-grade, non-metastatic, resectable osteosarcoma. The pattern of outcome was generally similar in a small cohort of patients with metastatic disease who were enrolled in this trial. Mifamurtide is generally well tolerated; adverse events attributed to administration of the drug include chills, fever, headache, nausea, and myalgias. Based on the available data, mifamurtide can be considered for inclusion in treatment protocols for localized osteosarcoma.

Biotin-directed assembly of targeted modular lipoplexes and their transfection of human hepatoma cells in vitro.

The asialoglycoprotein receptor, which is abundantly and near exclusively expressed on hepatocytes, has received much attention in the design of non-viral hepatotropic DNA delivery systems. Thus, asialoglycoproteins and hexopyranosyl ligands have been coupled to DNA-binding cationic polymers and liposomes in the assembly of complexes intended for uptake by liver parenchymal cells. The aim of the study was to construct a hepatocyte-targeted multimodular liposome-based transfecting complex, in which the biotin-streptavidin interaction provides the cohesive force between the ligand asialorosomucoid and the liposome bilayer, and to evaluate its transfection capabilities in the hepatocyte-derived human transformed cell line HepG2. Dibiotinylated asialoorosomucoid was attached to cationic liposomes constructed from 3beta[N-(N',N'-dimethylaminopropane)-carbamoyl] cholesterol (Chol-T):dioleoylphosphatidylethanolamine:biotinylcholesterylformylhydrazide (MSB1) (48:50:2 mole ratio) through streptavidin interposition. Liposome-pGL3 DNA interactions were studied by gel band shift and ethidium displacement assays. The cytotoxicity of assemblies was evaluated in the HepG2 cell line and transfection capabilities determined by measuring the activity of the transgene luciferase. Binding assays showed that all DNA was liposome associated at a DNA (negative):liposome (positive) charge ratio of 1:1. Accommodation of a streptavidin dibiotinylated asialoorosomucoid assembly was achieved at a DNA:liposome:streptavidin dibiotinylated asialoorosomucoid ratio of 1:4:9 (weight basis). Complexes showed optimal transfection activity at this ratio, which was reduced 10-fold by the presence of the competing ligand asialofetuin. The streptavidin-biotin interaction has been applied for the first time to the assembly of hepatocyte-targeted lipoplexes that display asialoorosomucoid and that are well tolerated by a human hepatoma cell line in which transfection is demonstrably achieved by receptor mediation. Favorable size and charge ratio characteristics suggest that this system may be suitable for in vivo application.