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Abstract
Biomimetic nanoparticles are hybrid nanostructures in which the uppermost layer is similar to a cell membrane. In these nanoparticles, lipids and biopolymers can be organized to improve drug incorporation and delivery. This report provides instructions for the preparation and physical characterization of four different biomimetic nanoparticles: (1) polystyrene sulphate (PSS) nanoparticles covered with one cationic dioctadecyl dimethylammonium bromide bilayer (DODAB), which incorporates dimeric channels of the antimicrobial peptide Gramicidin D; (2) silica nanoparticles covered with one single bilayer of the antimicrobial cationic lipid DODAB; (3) hybrid lipid/polymer indomethacin (IND) nanoparticles from injection of IND/DODAB ethanolic solution in a water solution of carboxymethyl cellulose (CMC); (4) bactericidal and fungicidal nanoparticles from DODAB bilayer fragments (BF) covered consecutively by a CMC and a poly(diallyl dimethyl ammonium chloride) (PDDA) layer. These examples provide the basis for the preparation and characterization of novel biomimetic nanoparticles with lipids and/or biopolymers in their composition. The polymers and lipids in the hybrid nanoparticle composition may impart stability and/or bioactivity and/or provide adequate microenvironments for carrying bioactive drugs and biomolecules.
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Affiliation(s)
- Ana Maria Carmona-Ribeiro
- Biocolloids Laboratory, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil.
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Carmona-Ribeiro AM, Pérez-Betancourt Y. Cationic Nanostructures for Vaccines Design. Biomimetics (Basel) 2020; 5:biomimetics5030032. [PMID: 32645946 PMCID: PMC7560170 DOI: 10.3390/biomimetics5030032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 12/20/2022] Open
Abstract
Subunit vaccines rely on adjuvants carrying one or a few molecular antigens from the pathogen in order to guarantee an improved immune response. However, to be effective, the vaccine formulation usually consists of several components: an antigen carrier, the antigen, a stimulator of cellular immunity such as a Toll-like Receptors (TLRs) ligand, and a stimulator of humoral response such as an inflammasome activator. Most antigens are negatively charged and combine well with oppositely charged adjuvants. This explains the paramount importance of studying a variety of cationic supramolecular assemblies aiming at the optimal activity in vivo associated with adjuvant simplicity, positive charge, nanometric size, and colloidal stability. In this review, we discuss the use of several antigen/adjuvant cationic combinations. The discussion involves antigen assembled to 1) cationic lipids, 2) cationic polymers, 3) cationic lipid/polymer nanostructures, and 4) cationic polymer/biocompatible polymer nanostructures. Some of these cationic assemblies revealed good yet poorly explored perspectives as general adjuvants for vaccine design.
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Ribeiro RT, Braga VHA, Carmona-Ribeiro AM. Biomimetic Cationic Nanoparticles Based on Silica: Optimizing Bilayer Deposition from Lipid Films. Biomimetics (Basel) 2017; 2:E20. [PMID: 31105181 PMCID: PMC6352667 DOI: 10.3390/biomimetics2040020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/16/2017] [Accepted: 10/18/2017] [Indexed: 11/17/2022] Open
Abstract
The optimization of bilayer coverage on particles is important for a variety of biomedical applications, such as drug, vaccine, and genetic material delivery. This work aims at optimizing the deposition of cationic bilayers on silica over a range of experimental conditions for the intervening medium and two different assemblies for the cationic lipid, namely, lipid films or pre-formed lipid bilayer fragments. The lipid adsorption on silica in situ over a range of added lipid concentrations was determined from elemental analysis of carbon, hydrogen, and nitrogen and related to the colloidal stability, sizing, zeta potential, and polydispersity of the silica/lipid nanoparticles. Superior bilayer deposition took place from lipid films, whereas adsorption from pre-formed bilayer fragments yielded limiting adsorption below the levels expected for bilayer adsorption.
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Affiliation(s)
- Rodrigo T Ribeiro
- Biocolloids Laboratory, Instituto de Química, Universidade de São Paulo, Av. Lineu Prestes 748, São Paulo 05508-000, SP, Brazil.
| | - Victor H A Braga
- Biocolloids Laboratory, Instituto de Química, Universidade de São Paulo, Av. Lineu Prestes 748, São Paulo 05508-000, SP, Brazil.
| | - Ana M Carmona-Ribeiro
- Biocolloids Laboratory, Instituto de Química, Universidade de São Paulo, Av. Lineu Prestes 748, São Paulo 05508-000, SP, Brazil.
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Intact deposition of cationic vesicles on anionic cellulose fibers: Role of vesicle size, polydispersity, and substrate roughness studied via streaming potential measurements. J Colloid Interface Sci 2016; 473:152-61. [DOI: 10.1016/j.jcis.2016.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 11/17/2022]
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Voisin H, Aimé C, Coradin T. Understanding and Tuning Bioinorganic Interfaces for the Design of Bionanocomposites. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Wu FG, Wu RG, Sun HY, Zheng YZ, Yu ZW. Demixing and crystallization of DODAB in DPPC-DODAB binary mixtures. Phys Chem Chem Phys 2014; 16:15307-18. [PMID: 24943895 DOI: 10.1039/c4cp01707b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The crystallization mechanism of one lipid component within multicomponent lipid mixtures remains unclear. To shed light on this issue, we studied the demixing and crystallization behaviors of a binary lipid system using neutral dipalmitoylphosphatidylcholine (DPPC) and cationic dioctadecyldimethylammonium bromide (DODAB) as model molecules. The results indicate that when DODAB is no more than equimolar (e.g., DPPC/DODAB = 2/1 and 1/1), DPPC is miscible with DODAB and hinders the crystallization of DODAB, and the samples undergo reversible gel-fluid phase transitions upon heating and cooling. However, when DODAB is dominant in the mixture (DPPC/DODAB = 1/2), cooling of the mixed fluid phase results in the formation of a DODAB-rich gel domain and a DPPC-DODAB mixed gel domain. Such phase-separated mixed gels can undergo further demixing and crystallization, producing a DODAB-rich crystalline domain and a DPPC-rich tilted gel domain upon prolonged (or plus low-temperature) incubation. Besides, evidence has been given that the crystallized DODAB-rich domain remains in the same lipid bilayer as the DPPC-rich domain. All the three binary lipid mixtures can hold large amounts of water in the lipid interlamellar regions, allowing the incorporation of a large number of water-soluble substances such as DNA or proteins, which can be used for the fabrication of functional biofilms and biomaterials. Influences of water content and salt concentration on the phase structures (e.g., repeat distances) of the binary mixtures have also been studied.
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Affiliation(s)
- Fu-Gen Wu
- Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
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Sorkin R, Dror Y, Kampf N, Klein J. Mechanical stability and lubrication by phosphatidylcholine boundary layers in the vesicular and in the extended lamellar phases. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5005-5014. [PMID: 24708462 DOI: 10.1021/la500420u] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The lubrication properties of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) extended supported bilayers were studied and compared to those of surface-attached DSPC small unilamellar vesicles (liposomes) in order to elucidate the effect of phospholipid geometrical packaging on the lubrication and mechanical properties of these boundary layers. The topography and response to the nanoindentation of bilayer- and liposome-covered surfaces were studied by an atomic force microscope (AFM). In parallel, normal and shear (frictional) forces between two opposing surfaces bearing DSPC vesicles/bilayers across water were studied with the surface force balance (SFB). A correlation between nanomechanical performance in the AFM and stability and lubrication in the SFB was observed. Bilayers were readily punctured by the AFM tip and exhibited substantial hysteresis between approach and retraction curves, whereas liposomes were not punctured and exhibited purely elastic behavior. At the same time, SFB measurements showed that bilayers are less stable and less efficient lubricants compared to liposomes. Bilayers provided efficient lubrication with very low friction coefficients, 0.002-0.008 up to pressures of more then 50 atm. However, bilayers were less robust and tended to detach from the surface as a result of shear, leading to high friction for subsequent approaches at the same contact position. In contrast, liposomes showed reversible and reproducible behavior under shear and compression, exhibiting ultralow friction coefficients of μ ≈ 10(-4) for pressures as high as 180 atm. This is attributed to the increased mechanical stability of the self-closed, closely packed liposomes, which we believe results from the more defect-free nature of the finitely sized vesicles.
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Affiliation(s)
- Raya Sorkin
- Department of Materials and Interfaces, Weizmann Institute of Science , Rehovot 76100, Israel
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Mukhametshina AR, Mustafina AR, Davydov NA, Nizameev IR, Kadirov MK, Gorbatchuk VV, Konovalov AI. The energy transfer based fluorescent approach to detect the formation of silica supported phosphatidylcholine and phosphatidylserine containing bilayers. Colloids Surf B Biointerfaces 2014; 115:93-9. [DOI: 10.1016/j.colsurfb.2013.11.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/12/2013] [Accepted: 11/15/2013] [Indexed: 11/25/2022]
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Preparation and characterization of biomimetic nanoparticles for drug delivery. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2012; 906:283-94. [PMID: 22791441 DOI: 10.1007/978-1-61779-953-2_22] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Biomimetic nanoparticles are hybrid nanostructures in which the uppermost layer is similar to a cell membrane. This report provides instructions for the preparation and physical characterization of three different types of biomimetic nanoparticles: (1) polystyrene sulfate nanoparticles covered with one cationic dioctadecyldimethylammonium bilayer; (2) silica nanoparticles covered with one neutral phosphatidylcholine bilayer; (3) miconazole particles covered with one anionic dihexadecylphosphate (DHP) bilayer. These examples provide the basis for the preparation and characterization of novel nanoparticles from hydrophobic or hydrophilic and organic or inorganic nanoparticle cores covered with functional outer layers. The major concepts and technical details for obtaining the optimal lipid coverage of supporting cores and for nanoparticle characterization are discussed.
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Gong YK, Winnik FM. Strategies in biomimetic surface engineering of nanoparticles for biomedical applications. NANOSCALE 2012; 4:360-8. [PMID: 22134705 DOI: 10.1039/c1nr11297j] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Engineered nanoparticles (NPs) play an increasingly important role in biomedical sciences and in nanomedicine. Yet, in spite of significant advances, it remains difficult to construct drug-loaded NPs with precisely defined therapeutic effects, in terms of release time and spatial targeting. The body is a highly complex system that imposes multiple physiological and cellular barriers to foreign objects. Upon injection in the blood stream or following oral administation, NPs have to bypass numerous barriers prior to reaching their intended target. A particularly successful design strategy consists in masking the NP to the biological environment by covering it with an outer surface mimicking the composition and functionality of the cell's external membrane. This review describes this biomimetic approach. First, we outline key features of the composition and function of the cell membrane. Then, we present recent developments in the fabrication of molecules that mimic biomolecules present on the cell membrane, such as proteins, peptides, and carbohydrates. We present effective strategies to link such bioactive molecules to the NPs surface and we highlight the power of this approach by presenting some exciting examples of biomimetically engineered NPs useful for multimodal diagnostics and for target-specific drug/gene delivery applications. Finally, critical directions for future research and applications of biomimetic NPs are suggested to the readers.
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Affiliation(s)
- Yong-kuan Gong
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, PR China.
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Investigation of DPPC effect on SiO2 particles and in the presence of phospho(lipases) by zeta potential and effective diameter measurements. POWDER TECHNOL 2011. [DOI: 10.1016/j.powtec.2011.07.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Ross EE, Mok SW, Bugni SR. Assembly of lipid bilayers on silica and modified silica colloids by reconstitution of dried lipid films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:8634-8644. [PMID: 21634797 DOI: 10.1021/la200952c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A method is presented for the assembly of lipid bilayers on silica colloids via reconstitution of dried lipid films solvent-cast from chloroform within packed beds of colloids ranging from 100 nm to 10 μm in diameter. Rapid solvent evaporation from the packed bed void volume results in uniform distribution of dried lipid throughout the colloidal bed. Fluorescence measurements indicate that significant, if not quantitative, retention of DOPC or DPPC films cast between sub-bilayer and multilayer quantities occurs when the colloids are redispersed in aqueous solution. Phospholipid bilayers assembled in this manner are shown to effectively passivate the surface of 250 nm colloids to nonspecific adsorption of bovine serum albumin. The method is shown to be capable of preparing supported bilayers on colloid surfaces that do not generally support vesicle fusion such as poly(ethylene glycol) (PEG) modified silica colloids. Bilayers of lipids that have not been reported to self-assemble by vesicle fusion, including gel-phase lipids and single-chain diacetylene amphiphiles, can also be formed by this method. The utility of the solid-core support is demonstrated by the facile assembly of supported lipid bilayers within fused silica capillaries to generate materials that are potentially suitable for the analysis of membrane interactions in a microchannel format.
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Affiliation(s)
- Eric E Ross
- Department of Chemistry & Biochemistry, Gonzaga University, Spokane, Washington 99258, United States.
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Oleson TA, Sahai N, Pedersen JA. Electrostatic effects on deposition of multiple phospholipid bilayers at oxide surfaces. J Colloid Interface Sci 2010; 352:327-36. [DOI: 10.1016/j.jcis.2010.08.057] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 11/27/2022]
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Meyer R, Sonnen AFP, Nau WM. Phase-dependent lateral diffusion of α-tocopherol in DPPC liposomes monitored by fluorescence quenching. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14723-14729. [PMID: 20722430 DOI: 10.1021/la101915x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The temperature-dependent fluorescence quenching of an amphiphilic palmitoyl derivative of 2,3-diazabicyclo[2.2.2]oct-2-ene (Fluorazophore-L) by α-tocopherol (α-Toc) has been determined in liposomes composed of a saturated lipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). The mutual lateral diffusion coefficients (D(L)) were extracted according to a laterally diffusion-controlled dynamic quenching model. Three distinct temperature regimes were identified: one between 65 and 39 °C, where the lateral diffusion coefficients were in the range of 10(-7) cm(2) s(-1) and the lifetime of the probe was monoexponential in the absence of α-Toc, a second one between 39 and 30 °C, where the lateral diffusion coefficients were in the range of 10(-8) cm(2) s(-1) and the lifetime of the probe was biexponential in the absence of α-Toc, and a third one below 30 °C, in which no diffusion was detectable, suggesting D(L) < 10(-9) cm(2)s (-1). These temperature domains were assigned, supported by differential scanning calorimetry (DSC) measurements, to the liquid-crystalline, ripple, and solid-gel phases of DPPC liposomes in the presence of the two additives. The absolute values of the individual lateral diffusion coefficients (taken as (1)/(2) of the D(L) values) of the Fluorazophore-L/α-Toc (ca. 2.5 × 10(-7) cm(2) s(-1) at 52 °C) couple demonstrates that α-Toc does not diffuse at an unexpectedly high rate in comparison to the self-diffusion of DPPC (1.5 × 10(-7) cm(2) s(-1) at 52 °C). However, diffusion in DPPC liposomes is distinctly slower than that in POPC ones (e.g., D(L) = 4.9 × 10(-7) cm(2) s(-1) versus 6.4 × 10(-7) cm(2) s(-1) at 50 °C), with an activation energy of 49 ± 5 kJ mol(-1) (value for POPC: 47 ± 5 kJ mol(-1)), in the temperature range of the liquid-crystalline phase. Diffusion in the ripple phase, that is, below the main phase transition temperature, was found to be non-negligible, with an apparent activation energy of 175 ± 50 kJ mol(-1).
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Affiliation(s)
- Roland Meyer
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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Bucak S, Wang C, Laibinis PE, Hatton TA. Dynamics of supported lipid bilayer deposition from vesicle suspensions. J Colloid Interface Sci 2010; 348:608-14. [DOI: 10.1016/j.jcis.2010.04.087] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
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Savarala S, Ahmed S, Ilies MA, Wunder SL. Formation and colloidal stability of DMPC supported lipid bilayers on SiO2 nanobeads. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12081-12088. [PMID: 20527833 DOI: 10.1021/la101304v] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Supported lipid bilayers (SLBs) of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) were formed on 20-100 nm silica (SiO(2)) nanobeads, and the formation was accompanied by an 8 nm increase in diameter of the SiO(2), consistent with single nanobeads surrounded by a DMPC bilayer. Complete SLBs were formed when the nominal surface areas of the DMPC matched that of the silica, SA(DMPC)/SA(SiO2) = 1, and required increasing ionic strength and time to form on smaller size nanobeads, as shown by a combination of nano-differential scanning calorimetry (nano-DSC), dynamic light scattering (DLS), and zeta potential (zeta) measurements. For 5 nm SiO(2), where the nanoparticle and DMPC dimensions were comparable, DMPC fused and formed SLBs on the nanobeads, but it did not form single bilayers around them. Instead, stable agglomerates of 150-1000 nm were formed over a wide surface ratio range (0.25 < or = SA(DMPC)/SA(SiO2) < 2) in 0.75 mM NaCl. At ionic strengths > 1 mM NaCl, charge shielding, as measured by zeta potential measurements (zeta --> 0), resulted in precipitation of the SLBs.
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Affiliation(s)
- Sushma Savarala
- Department of Chemistry, College of Science and Technology, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, USA
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Carmona-Ribeiro AM. Biomimetic nanoparticles: preparation, characterization and biomedical applications. Int J Nanomedicine 2010; 5:249-59. [PMID: 20463941 PMCID: PMC2865020 DOI: 10.2147/ijn.s9035] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Indexed: 11/23/2022] Open
Abstract
Mimicking nature is a powerful approach for developing novel lipid-based devices for drug and vaccine delivery. In this review, biomimetic assemblies based on natural or synthetic lipids by themselves or associated to silica, latex or drug particles will be discussed. In water, self-assembly of lipid molecules into supramolecular structures is fairly well understood. However, their self-assembly on a solid surface or at an interface remains poorly understood. In certain cases, hydrophobic drug granules can be dispersed in aqueous solution via lipid adsorption surrounding the drug particles as nanocapsules. In other instances, hydrophobic drug molecules attach as monomers to borders of lipid bilayer fragments providing drug formulations that are effective in vivo at low drug-to-lipid-molar ratio. Cationic biomimetic particles offer suitable interfacial environment for adsorption, presentation and targeting of biomolecules in vivo. Thereby antigens can effectively be presented by tailored biomimetic particles for development of vaccines over a range of defined and controllable particle sizes. Biomolecular recognition between receptor and ligand can be reconstituted by means of receptor immobilization into supported lipidic bilayers allowing isolation and characterization of signal transduction steps.
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Affiliation(s)
- Ana Maria Carmona-Ribeiro
- Biocolloids Lab, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
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Lincopan N, Santana MR, Faquim-Mauro E, da Costa MHB, Carmona-Ribeiro AM. Silica-based cationic bilayers as immunoadjuvants. BMC Biotechnol 2009; 9:5. [PMID: 19152701 PMCID: PMC2647919 DOI: 10.1186/1472-6750-9-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Accepted: 01/19/2009] [Indexed: 11/26/2022] Open
Abstract
Background Silica particles cationized by dioctadecyldimethylammonium bromide (DODAB) bilayer were previously described. This work shows the efficiency of these particulates for antigen adsorption and presentation to the immune system and proves the concept that silica-based cationic bilayers exhibit better performance than alum regarding colloid stability and cellular immune responses for vaccine design. Results Firstly, the silica/DODAB assembly was characterized at 1 mM NaCl, pH 6.3 or 5 mM Tris.HCl, pH 7.4 and 0.1 mg/ml silica over a range of DODAB concentrations (0.001–1 mM) by means of dynamic light scattering for particle sizing and zeta-potential analysis. 0.05 mM DODAB is enough to produce cationic bilayer-covered particles with good colloid stability. Secondly, conditions for maximal adsorption of bovine serum albumin (BSA) or a recombinant, heat-shock protein from Mycobacterium leprae (18 kDa-hsp) onto DODAB-covered or onto bare silica were determined. At maximal antigen adsorption, cellular immune responses in vivo from delayed-type hypersensitivity reactions determined by foot-pad swelling tests (DTH) and cytokines analysis evidenced the superior performance of the silica/DODAB adjuvant as compared to alum or antigens alone whereas humoral response from IgG in serum was equal to the one elicited by alum as adjuvant. Conclusion Cationized silica is a biocompatible, inexpensive, easily prepared and possibly general immunoadjuvant for antigen presentation which displays higher colloid stability than alum, better performance regarding cellular immune responses and employs very low, micromolar doses of cationic and toxic synthetic lipid.
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Affiliation(s)
- Nilton Lincopan
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Caixa Postal 26077, São Paulo-SP, Brazil
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Sobral CN, Soto MA, Carmona-Ribeiro AM. Characterization of DODAB/DPPC vesicles. Chem Phys Lipids 2008; 152:38-45. [DOI: 10.1016/j.chemphyslip.2007.12.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 11/23/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
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