1
|
Sabir F, Farooq RK, Asim.ur.Rehman, Ahmed N. Monocyte as an Emerging Tool for Targeted Drug Delivery: A Review. Curr Pharm Des 2019; 24:5296-5312. [DOI: 10.2174/1381612825666190102104642] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 12/21/2018] [Indexed: 12/30/2022]
Abstract
Monocytes are leading component of the mononuclear phagocytic system that play a key role in phagocytosis and removal of several kinds of microbes from the body. Monocytes are bone marrow precursor cells that stay in the blood for a few days and migrate towards tissues where they differentiate into macrophages. Monocytes can be used as a carrier for delivery of active agents into tissues, where other carriers have no significant access. Targeting monocytes is possible both through passive and active targeting, the former one is simply achieved by enhanced permeation and retention effect while the later one by attachment of ligands on the surface of the lipid-based particulate system. Monocytes have many receptors e.g., mannose, scavenger, integrins, cluster of differentiation 14 (CD14) and cluster of differentiation 36 (CD36). The ligands used against these receptors are peptides, lectins, antibodies, glycolipids, and glycoproteins. This review encloses extensive introduction of monocytes as a suitable carrier system for drug delivery, the design of lipid-based carrier system, possible ways for delivery of therapeutics to monocytes, and the role of monocytes in the treatment of life compromising diseases such as cancer, inflammation, stroke, etc.
Collapse
Affiliation(s)
- Fakhara Sabir
- Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Rai K. Farooq
- Department of Neuroscience Research, Institute of Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, P.O Box 1982, Dammam 31441, Saudi Arabia
| | - Asim.ur.Rehman
- Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Naveed Ahmed
- Department of Pharmacy, Quaid-i-Azam University, Islamabad 45320, Pakistan
| |
Collapse
|
2
|
Ríos-Marco P, Marco C, Gálvez X, Jiménez-López JM, Carrasco MP. Alkylphospholipids: An update on molecular mechanisms and clinical relevance. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1657-1667. [PMID: 28238819 DOI: 10.1016/j.bbamem.2017.02.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 11/16/2022]
Abstract
Alkylphospholipids (APLs) represent a new class of drugs which do not interact directly with DNA but act on the cell membrane where they accumulate and interfere with lipid metabolism and signalling pathways. This review summarizes the mode of action at the molecular level of these compounds. In this sense, a diversity of mechanisms has been suggested to explain the actions of clinically-relevant APLs, in particular, in cancer treatment. One consistently reported finding is that APLs reduce the biosynthesis of phosphatidylcholine (PC) by inhibiting the rate-limiting enzyme CTP:phosphocholine cytidylyltransferase (CT). APLs also alter intracellular cholesterol traffic and metabolism in human tumour-cell lines, leading to an accumulation of cholesterol inside the cell. An increase in cholesterol biosynthesis associated with a decrease in the synthesis of choline-containing phospholipids and cholesterol esterification leads to a change in the free-cholesterol:PC ratio in cells exposed to APLs. Akt phosphorylation status after APL exposure shows that this critical regulator for cell survival is modulated by changes in cholesterol levels induced in the plasma membrane by these lipid analogues. Furthermore, APLs produce cell ultrastructural alterations with an abundant autophagic vesicles and autolysosomes in treated cells, indicating an interference of autophagy process after APL exposure. Thus, antitumoural APLs interfere with the proliferation of tumour cells via a complex mechanism involving phospholipid and cholesterol metabolism, interfere with lipid-dependent survival-signalling pathways and autophagy. Although APLs also exert antiparasitic, antibacterial, and antifungal effects, in this review we provide a summary of the antileishmanial activity of these lipid analogues. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
Collapse
Affiliation(s)
- Pablo Ríos-Marco
- Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, Granada 18001, Spain
| | - Carmen Marco
- Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, Granada 18001, Spain
| | - Xiomara Gálvez
- Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, Granada 18001, Spain
| | - José M Jiménez-López
- Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, Granada 18001, Spain.
| | - María P Carrasco
- Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, Granada 18001, Spain.
| |
Collapse
|
3
|
A pH-sensitive stearoyl-PEG-poly(methacryloyl sulfadimethoxine)-decorated liposome system for protein delivery: An application for bladder cancer treatment. J Control Release 2016; 238:31-42. [PMID: 27444816 DOI: 10.1016/j.jconrel.2016.07.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 07/05/2016] [Accepted: 07/15/2016] [Indexed: 01/19/2023]
Abstract
Stealth pH-responsive liposomes for the delivery of therapeutic proteins to the bladder epithelium were prepared using methoxy-poly(ethylene glycol)5kDa-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (mPEG5kDa-DSPE) and stearoyl-poly(ethylene glycol)-poly(methacryloyl sulfadimethoxine) copolymer (stearoyl-PEG-polySDM), which possesses an apparent pKa of 7.2. Liposomes of 0.2:0.6:100, 0.5:1.5:100 and 1:3:100 mPEG5kDa-DSPE/stearoyl-PEG-polySDM/(soybean phosphatidylcholine+cholesterol) molar ratios were loaded with bovine serum albumin (BSA) as a protein model. The loading capacity was 1.3% w/w BSA/lipid. At pH7.4, all liposome formulations displayed a negative zeta-potential and were stable for several days. By pH decrease or addition to mouse urine, the zeta potential strongly decreased, and the liposomes underwent a rapid size increase and aggregation. Photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM) analyses showed that the extent of the aggregation depended on the stearoyl-PEG-polySDM/lipid molar ratio. Cytofluorimetric analysis and confocal microscopy showed that at pH6.5, the incubation of MB49 mouse bladder cancer cells and macrophages with fluorescein isothiocyanate-labelled-BSA (FITC-BSA) loaded and N-(Lissamine Rhodamine B sulfonyl)-1, 2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (rhodamine-DHPE) labelled 1:3:100 mPEG5kDa-DSPE/stearoyl-PEG-polySDM/lipid molar ratio liposomes resulted in a time-dependent liposome association with the cells. At pH7.4, the association of BSA-loaded liposomes with the MB49 cells and macrophages was remarkably lower than at pH6.5. Confocal images of bladder sections revealed that 2h after the instillation, liposomes at pH7.4 and control non-responsive liposomes at pH7.4 or 6.5 did not associate nor delivered FITC-BSA to the bladder epithelium. On the contrary, the pH-responsive liposome formulation set at pH6.5 and soon administered to mice by bladder instillation showed that, 2h after administration, the pH-responsive liposomes efficiently delivered the loaded FITC-BSA to the bladder epithelium.
Collapse
|
4
|
Transfecting Human Monocytes with RNA. Methods Mol Biol 2016. [PMID: 27236800 DOI: 10.1007/978-1-4939-3625-0_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Targeting monocytes as a delivery system for drugs or nucleic acids, and thereby harnessing their natural tissue-infiltrating capacity, has become an area of intense investigation in both basic and clinical research. Herein we describe an efficient method to deliver mRNA (messenger RNA) or siRNA (small interfering RNA) into human monocytes by electroporation. This method can be applied in the laboratory to monocytes isolated via magnetic bead-based techniques, or in a clinical setting using monocytes that were collected via counterflow centrifugation elutriation using the Elutra(®) Cell Separation System. We further demonstrate that electroporation of monocytes with RNA represents a robust and highly relevant approach to modify monocytes for cell-based therapies. Last, the procedure described can readily be adapted to monocytes from different species, hence facilitating research in animal models.
Collapse
|
5
|
Patel B, Gupta N, Ahsan F. Particle engineering to enhance or lessen particle uptake by alveolar macrophages and to influence the therapeutic outcome. Eur J Pharm Biopharm 2015; 89:163-74. [DOI: 10.1016/j.ejpb.2014.12.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 11/26/2014] [Accepted: 12/02/2014] [Indexed: 12/23/2022]
|
6
|
Momen-Heravi F, Bala S, Bukong T, Szabo G. Exosome-mediated delivery of functionally active miRNA-155 inhibitor to macrophages. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2014; 10:1517-27. [PMID: 24685946 DOI: 10.1016/j.nano.2014.03.014] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/04/2014] [Accepted: 03/19/2014] [Indexed: 12/13/2022]
Abstract
Exosomes, membranous nanovesicles, naturally carry bio-macromolecules and play pivotal roles in both physiological intercellular crosstalk and disease pathogenesis. Here, we showed that B cell-derived exosomes can function as vehicles to deliver exogenous miRNA-155 mimic or inhibitor into hepatocytes or macrophages, respectively. Stimulation of B cells significantly increased exosome production. Unlike in parental cells, baseline level of miRNA-155 was very low in exosomes derived from stimulated B cells. Exosomes loaded with a miRNA-155 mimic significantly increased miRNA-155 levels in primary mouse hepatocytes and the liver of miRNA-155 knockout mice. Treatment of RAW macrophages with miRNA-155 inhibitor loaded exosomes resulted in statistically significant reduction in LPS-induced TNFα production and partially prevented LPS-induced decrease in SOCS1 mRNA levels. Furthermore, exosome-mediated miRNA-155 inhibitor delivery resulted in functionally more efficient inhibition and less cellular toxicity compared to conventional transfection methods. Similar approaches could be useful in modification of target biomolecules in vitro and in vivo. From the clinical editor: In this study, exosome-based delivery of miRNA-155 mimicker or inhibitor was found to have significant biological response in hepatocytes and macrophages. Exosome-based approaches may be useful in the modification of other target biomolecules.
Collapse
Affiliation(s)
- Fatemeh Momen-Heravi
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Shashi Bala
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Terence Bukong
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Gyongyi Szabo
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
| |
Collapse
|
7
|
Targeted liposomal drug delivery to monocytes and macrophages. JOURNAL OF DRUG DELIVERY 2010; 2011:727241. [PMID: 21512579 PMCID: PMC3065850 DOI: 10.1155/2011/727241] [Citation(s) in RCA: 241] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 09/27/2010] [Indexed: 01/27/2023]
Abstract
As the role of monocytes and macrophages in a range of diseases is better understood, strategies to target these cell types are of growing importance both scientifically and therapeutically. As particulate carriers, liposomes naturally target cells of the mononuclear phagocytic system (MPS), particularly macrophages. Loading drugs into liposomes can therefore offer an efficient means of drug targeting to MPS cells. Physicochemical properties including size, charge and lipid composition can have a very significant effect on the efficiency with which liposomes target MPS cells. MPS cells express a range of receptors including scavenger receptors, integrins, mannose receptors and Fc-receptors that can be targeted by the addition of ligands to liposome surfaces. These ligands include peptides, antibodies and lectins and have the advantages of increasing target specificity and avoiding the need for cationic lipids to trigger intracellular delivery. The goal for targeting monocytes/macrophages using liposomes includes not only drug delivery but also potentially a role in cell ablation and cell activation for the treatment of conditions including cancer, atherosclerosis, HIV, and chronic inflammation.
Collapse
|
8
|
Macrophage roles following myocardial infarction. Int J Cardiol 2008; 130:147-58. [PMID: 18656272 DOI: 10.1016/j.ijcard.2008.04.059] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Revised: 03/13/2008] [Accepted: 04/04/2008] [Indexed: 12/11/2022]
Abstract
Following myocardial infarction (MI), circulating blood monocytes respond to chemotactic factors, migrate into the infarcted myocardium, and differentiate into macrophages. At the injury site, macrophages remove necrotic cardiac myocytes and apoptotic neutrophils; secrete cytokines, chemokines, and growth factors; and modulate phases of the angiogenic response. As such, the macrophage is a primary responder cell type that is involved in the regulation of post-MI wound healing at multiple levels. This review summarizes what is currently known about macrophage functions post-MI and borrows literature from other injury and inflammatory models to speculate on additional roles. Basic science and clinical avenues that remain to be explored are also discussed.
Collapse
|
9
|
Affiliation(s)
- J E Dancey
- Investigational Drug Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Rockville, MD, USA
| |
Collapse
|
10
|
Andresen TL, Jensen SS, Jørgensen K. Advanced strategies in liposomal cancer therapy: problems and prospects of active and tumor specific drug release. Prog Lipid Res 2005; 44:68-97. [PMID: 15748655 DOI: 10.1016/j.plipres.2004.12.001] [Citation(s) in RCA: 400] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Tumor specific drug delivery has become increasingly interesting in cancer therapy, as the use of chemotherapeutics is often limited due to severe side effects. Conventional drug delivery systems have shown low efficiency and a continuous search for more advanced drug delivery principles is therefore of great importance. In the first part of this review, we present current strategies in the drug delivery field, focusing on site-specific triggered drug release from liposomes in cancerous tissue. Currently marketed drug delivery systems lack the ability to actively release the carried drug and rely on passive diffusion or slow non-specific degradation of the liposomal carrier. To obtain elevated tumor-to-normal tissue drug ratios, it is important to develop drug delivery strategies where the liposomal carriers are actively degraded specifically in the tumor tissue. Many promising strategies have emerged ranging from externally triggered light- and thermosensitive liposomes to receptor targeted, pH- and enzymatically triggered liposomes relying on an endogenous trigger mechanism in the cancerous tissue. However, even though several of these strategies were introduced three decades ago, none of them have yet led to marketed drugs and are still far from achieving this goal. The most advanced and prospective technologies are probably the prodrug strategies where non-toxic drugs are carried and activated specifically in the malignant tissue by overexpressed enzymes. In the second part of this paper, we review our own work, exploiting secretory phospholipase A2 as a site-specific trigger and prodrug activator in cancer therapy. We present novel prodrug lipids together with biophysical investigations of liposome systems, constituted by these new lipids and demonstrate their degradability by secretory phospholipase A2. We furthermore give examples of the biological performance of the enzymatically degradable liposomes as advanced drug delivery systems.
Collapse
Affiliation(s)
- Thomas L Andresen
- Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Lyngby, Denmark.
| | | | | |
Collapse
|
11
|
Jensen SS, Andresen TL, Davidsen J, Høyrup P, Shnyder SD, Bibby MC, Gill JH, Jørgensen K. Secretory phospholipase A2 as a tumor-specific trigger for targeted delivery of a novel class of liposomal prodrug anticancer etherlipids. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1451.3.11] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The use of many common clinically relevant chemotherapeutics is often limited due to insufficient delivery to the tumor and dose-limiting systemic toxicities. Therefore, therapeutics that specifically target tumor cells and are nontoxic to normal cells are required. Here, we report the development of a novel class of liposomes composed of lipid prodrugs, which use the increased secretory phospholipase A2 type IIA (sPLA2) activity of the tumor microenvironment as a trigger for the release of anticancer etherlipids (AEL). Treatment of sPLA2-secreting tumor cells in vitro with liposomes consisting of proAELs resulted in growth inhibition comparable with addition of the AELs alone. Using a specific sPLA2 inhibitor, we showed the low cytotoxicity of the nonhydrolyzed proAEL liposomes and have proven the sPLA2 dependency of the activation of proAELs to cytotoxic AELs. In addition, we showed that our proAEL liposomes circumvent the inherent hemolytic toxicities associated with the use of etherlipids, thereby allowing i.v. administration of such therapeutics as nontoxic prodrug liposomes. Furthermore, using a sPLA2-secreting human colon cancer xenograft model, we showed that the proAEL liposomes are capable of inducing a tumor growth delay in vivo. Taken together, these data support the validity of this novel tumor-selective liposomal prodrug delivery strategy. This new approach also provides a promising system for tumor-selective delivery and release of conventional chemotherapeutics encapsulated in the sPLA2-degradable prodrug liposomes.
Collapse
Affiliation(s)
| | - Thomas L. Andresen
- 1LiPlasome Pharma A/S and
- 2Department of Chemistry, Technical University of Denmark, Lyngby, Denmark and
| | | | | | - Steven D. Shnyder
- 3Cancer Research Unit, Tom Connors Cancer Research Centre, University of Bradford, Bradford, United Kingdom
| | - Michael C. Bibby
- 3Cancer Research Unit, Tom Connors Cancer Research Centre, University of Bradford, Bradford, United Kingdom
| | - Jason H. Gill
- 3Cancer Research Unit, Tom Connors Cancer Research Centre, University of Bradford, Bradford, United Kingdom
| | | |
Collapse
|
12
|
Duijsings D, Houweling M, Vaandrager AB, Mol JA, Teerds KJ. Hexadecylphosphocholine causes rapid cell death in canine mammary tumour cells. Eur J Pharmacol 2004; 502:185-93. [PMID: 15476744 DOI: 10.1016/j.ejphar.2004.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Accepted: 09/01/2004] [Indexed: 01/31/2023]
Abstract
Hexadecylphosphocholine (HePC, Miltefosine) is an antitumour phospholipid and known inducer of apoptosis in human breast cancer cells. The mechanism underlying the induction of cell death by HePC, however, is not clear yet. In this study, we have investigated the cytotoxic effects of HePC on canine mammary tumour cells (CMTs) in vitro. Upon addition of HePC, CMTs rapidly exhibited several features that resembled apoptotic cell death. Cells showed externalization of phosphatidylserine, a hallmark of apoptosis, within 5 min after addition of HePC at concentrations as low as 10 microM. Furthermore, rapid swelling of mitochondria was observed. Rounding and detachment of cells followed within 30 min. However, fragmentation of nuclear DNA could not be observed. Overall, HePC was shown to induce a type of cell death in CMTs that in some aspects resembles apoptosis, though the process proceeds much more rapidly than reported for other tumour cell lines.
Collapse
Affiliation(s)
- Daniël Duijsings
- Department of Biochemistry and Cell biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
13
|
Samdani AF, Kuchner EB, Rhines L, Adamson DC, Lawson C, Tyler B, Brem H, Dawson VL, Dawson TM. Astroglia Induce Cytotoxic Effects on Brain Tumors via a Nitric Oxide-Dependent Pathway Both in Vitro and in Vivo. Neurosurgery 2004; 54:1231-7; discussion 1237-8. [PMID: 15113479 DOI: 10.1227/01.neu.0000119576.76193.b8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2003] [Accepted: 01/14/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE In the central nervous system, astroglia produce nitric oxide (NO) in response to cytokines. We investigated whether cytokine stimulation of astroglia could inhibit brain tumor cell growth in vitro and prolong survival in vivo via an NO-dependent pathway. METHODS Astroglia cultures were stimulated with the cytokines lipopolysaccharide and interferon-gamma and subsequently seeded with tumor cell lines. Wild-type mice and inducible NO synthase-knockout mice received in vivo cytokine stimulation followed by B16F10 murine melanoma challenge. RESULTS Our in vitro studies demonstrate that astroglia stimulated to produce NO by the addition of cytokines dose-dependently inhibit the growth of one primary rat brain tumor cell line (9L) and three primary human brain tumor cell lines (H80, U87, and U373). This inhibition of tumor cell growth is also observed in metastatic cell lines (B16F10 melanoma, Lewis lung carcinoma, and CT26 colon). Cultured astrocytes from inducible NO synthase-knockout mice, which are incapable of induction of NO, are without the enhanced tumoricidal effect. Furthermore, when C57BL/6 mice are primed to produce NO through stereotactic intracranial administration of lipopolysaccharide plus interferon-gamma and subsequently challenged with B16F10 murine melanoma, survival is significantly prolonged, with a median survival of 26 days versus 16 days in the control group (P < 0.001). The addition of an NO synthase inhibitor (N(G)-nitro-l-arginine methyl ester) decreases this beneficial effect (median survival, 21 d). CONCLUSION These findings suggest that NO may have an important role as a defense mechanism molecule against brain tumors; stimulation or modification of this mechanism may represent a new approach to the treatment of primary and metastatic brain tumors.
Collapse
Affiliation(s)
- Amer F Samdani
- Department of Neurological Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Moghimi SM, Szebeni J. Stealth liposomes and long circulating nanoparticles: critical issues in pharmacokinetics, opsonization and protein-binding properties. Prog Lipid Res 2004; 42:463-78. [PMID: 14559067 DOI: 10.1016/s0163-7827(03)00033-x] [Citation(s) in RCA: 794] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This article critically examines and evaluates the likely mechanisms that contribute to prolonged circulation times of sterically protected nanoparticles and liposomes. It is generally assumed that the macrophage-resistant property of sterically protected particles is due to suppression in surface opsonization and protein adsorption. However, recent evidence shows that sterically stabilized particles are prone to opsonization particularly by the opsonic components of the complement system. We have evaluated these phenomena and discussed theories that reconcile complement activation and opsonization with prolonged circulation times. With respect to particle longevity, the physiological state of macrophages also plays a critical role. For example, stimulated or newly recruited macrophages can recognize and rapidly internalize sterically protected nanoparticles by opsonic-independent mechanisms. These concepts are also examined.
Collapse
Affiliation(s)
- S M Moghimi
- Molecular Targeting and Polymer Toxicology Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, BN2 4GJ, Brighton, UK.
| | | |
Collapse
|
15
|
Saraiva VB, Gibaldi D, Previato JO, Mendonça-Previato L, Bozza MT, Freire-De-Lima CG, Heise N. Proinflammatory and cytotoxic effects of hexadecylphosphocholine (miltefosine) against drug-resistant strains of Trypanosoma cruzi. Antimicrob Agents Chemother 2002; 46:3472-7. [PMID: 12384352 PMCID: PMC128733 DOI: 10.1128/aac.46.11.3472-3477.2002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The increased resistance of the protozoan parasite Trypanosoma cruzi to nitro derivatives is one of the major problems for the successful treatment of Chagas' disease. In the present study, we have tested the effects of 1-O-hexadecylphosphocholine (miltefosine) against strains of T. cruzi that are partially resistant (strain Y) and highly resistant (strain Colombiana) to the drugs in clinical use. As expected, epimastigotes of strain Colombiana showed higher levels of resistance to benznidazole than those of strain Y. However, the level of resistance to miltefosine was the same for both strains. This alkylphospholipid was also extremely toxic against intracellular amastigotes of both strains. This ether-lipid analogue induced in a dose-dependent manner the production of tumor necrosis factor alpha and nitric oxide (NO) radicals by infected and noninfected macrophages, suggesting that miltefosine may activate macrophages in vitro. Nevertheless, the cytotoxic effect of miltefosine against intracellular amastigotes was independent of the amount of NO produced by the infected macrophages since the same dose-response curves for miltefosine were observed when the NO production was blocked by the NO synthase inhibitor N(G)-monomethyl-L-arginine monoacetate. Preliminary in vivo studies with BALB/c mice infected with strain Y indicated that oral miltefosine promoted survival and reduced the parasitemia to levels comparable to those observed when benznidazole was used. Four months after treatment, no parasites were detected in the blood or spleen tissue sections maintained in culture. Together, these results support the hypothesis that miltefosine may be used for the treatment of Chagas' disease, including cases caused by resistant strains of T. cruzi.
Collapse
Affiliation(s)
- Victor B Saraiva
- Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro-RJ, 21944-970, Brazil
| | | | | | | | | | | | | |
Collapse
|
16
|
Eue I. Hexadecylphosphocholine selectively upregulates expression of intracellular adhesion molecule-1 and class I major histocompatibility complex antigen in human monocytes. JOURNAL OF EXPERIMENTAL THERAPEUTICS AND ONCOLOGY 2002; 2:333-6. [PMID: 12440224 DOI: 10.1046/j.1359-4117.2002.01048.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
U 937 cells are widely used as a model system to study human monocytes, since they express typical human monocyte markers and properties. Hexadecylphosphocholine (HPC) is the main representative of a class of synthetic phospholipids, the alkylphosphocholines (APCs), and is able to form stable multilamellar vesicles (MLVs = liposomes) to deliver HPC to monocytes/macrophages. Here we report the ability of both micellar and liposomal HPC (L-HPC) to interact with human monocytes and upregulate specific adhesion molecules. Whereas CD14 could neither be induced by HPC nor by L-HPC on U 937 cells, intracellular adhesion molecule-1 and class 1 major histocompatibility complex (MHC-1) antigen were upregulated by both HPC and L-HPC in a dose-dependent manner. These data support and complete previous studies on HPC-induced activation of U 937 cells and provide additional mechanistic information on the initial steps of HPC-mediated recruitment of macrophages and their antitumor activity.
Collapse
|
17
|
Jiménez-López JM, Carrasco MP, Segovia JL, Marco C. Hexadecylphosphocholine inhibits phosphatidylcholine biosynthesis and the proliferation of HepG2 cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:4649-55. [PMID: 12230578 DOI: 10.1046/j.1432-1033.2002.03169.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hexadecylphosphocholine (HePC) is a synthetic lipid representative of a new group of antiproliferative agents, alkylphosphocholines (APC), which are promising candidates in anticancer therapy. Thus we have studied the action of HePC on the human hepatoblastoma cell line HepG2, which is frequently used as a model for studies into hepatic lipid metabolism. Non-toxic, micromolar concentrations of HePC exerted an antiproliferative effect on this hepatoma cell line. The incorporation into phosphatidylcholine (PC) of the exogenous precursor [methyl-14C]choline was substantially reduced by HePC. This effect was not due to any alteration in choline uptake by the cells, the degradation rate of PC or the release of PC into the culture medium. As anaccumulation of soluble choline derivatives points to CTP:phosphocholine cytidylyltransferase (CT) as the target of HePC activity we examined its effects on the different enzymes involved in the biosynthesis of PC via CDP-choline. Treatment with HePC altered neither the activity of choline kinase (CK) nor that of diacylglycerol cholinephosphotransferase (CPT), but it did inhibit CT activity in HepG2 cells. In vitro HePC also inhibited the activity of cytosolic but not membrane-bound CT. Taken together our results suggest that HePC interferes specifically with the biosynthesis of PC in HepG2 cells by depressing CT translocation to the membrane, which may well impair their proliferation.
Collapse
Affiliation(s)
- José M Jiménez-López
- Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Granada, Spain
| | | | | | | |
Collapse
|