Liposomes schematic representation

Fig. 11 Schematic representation of liposome interactions at a membrane surface.

Figure 1.1. Schematic representation of four major liposome types. Conventional liposomes are either neutral or negatively charged. Stealth liposomes are sterically stabilized and carry a polymer coating to obtain a prolonged circulation time in the body. Immunoliposomes are antibody targeted liposomes and can consist of either conventional or sterically stabilized liposomes. Positive charge on cationic liposomes can be created in various ways. Reproduced from reference [112] with permission.

Figure 8.3 Schematic representation of the effects of liposome and nanoparticle PEGylation.

FIGURE 9.5 Schematic representation of phospholipids distribution in lipid emulsions and liposomes. Both drug carrier systems show similar surface. The main differences between liposomes and lipid droplets are related to the mean diameter and nature of the inner contents. (From dos Santos, 2005.)... 

There is a wide variety of vectors used to deliver DNA or oligonucleotides into mammalian cells, either in vitro or in vivo. The most common vector systems are based on viral [retroviruses (9, 10), adeno-associated virus (AAV) (11), adenovirus (12, 13), herpes simplex virus (HSV) (14)] andnonviral [cationic liposomes (15,16), polymers and receptor-mediated polylysine-DNA] complexes (17). Other viral vectors that are currently under development are based on lentiviruses (18), human cytomegalovirus (CMV) (19), Epstein-Barr virus (EBV) (20), poxviruses (21), negative-strand RNA viruses (influenza virus), alphaviruses and herpesvirus saimiri (22). Also a hybrid adenoviral/retroviral vector has successfully been used for in vivo gene transduction (23). A simplified schematic representation of basic human gene therapy methods is described in Figure 13.1. 

Fig. 53. Schematic representation of possible routes to stabilize liposomes via surface coating with polymers...

Figure 18-5 Schematic representation of (a) a membrane lipid, (b) a bilayer structure formed by lipid molecules in polar media the interior of the bilayer is nonpolar, and (c) a continuous bilayer structure (liposome) with polar interior and exterior...

Fig. 25. Schematic representation of the transport experiment in which aqueous NaCl solution is added to a preparation of liposomes containing bouquet molecules in the membrane in aqueous LiCl solution, creating opposing gradients in Na+ and Li+ ion concentrations. The entry of Na+ ions, initially found only in the external volume, into liposomes is followed by 23Na NMR spectroscopy the exit of Li+ may also be followed by 7Li NMR spectroscopy.

FIGURE 7.38. Computer generated model of a liposome-streptavidin conjugate (a), a schematic representation of a liposome-streptavidin (Sav)-concanavalin A (Con A)-streptavidin multilayer (b) and of streptavidin crosslinked vesicles (c). 

Fig. 10.8 Schematic representation of the formation of pectin-liposome nanocomplexes (PLNs) (taken from Sriamornsak et al. 2008)...

Fig. 2. A Interaction of biotin with the tetrameric protein streptavidin. B Schematic representation of the aggregation of biotinylated liposomes induced by the tetrameric streptavidin protein (taken from [16])...

Fig. 3. Schematic representation of interacting PEG-coated liposome bilayers bearing the recognizable biotin group with avidin molecules dissolved in water...

Fig. 4. Schematic representation of the aggregation of liposome bilayers induced by complementary dendrimers...

Fig. 11. Schematic representation of molecular recognition of phosphatidylcholine-cholesterol based liposomes bearing the complementary guanidinium and phosphate moieties...

Fig. (9). Schematic representation some of the possible structures assumed by phospholipids in presence of aqueous phase (a) lipid billayer, (b) micelle, (c) liposome.

Figure 14. Schematic representation of amino acid transport by spirobenzopyran 23 across liposomal bilayers.

Fig. 9. (A) Schematic representation of photophosphoryiation in a reconstituted iiposome containing photosystem-l reaction centers and CFo Fi ATP synthase, both purified from spinach chloroplasts, using PMS as the electron donor/acoeptor system. (B) Rate of photophosphoryiation as a function of light intensity (left) and time dependence of reconstituted photophosphoryiation (right). Figure source (B) Hauska, Samoray, Orlich and Nelson (1980) Reconstitution of photosynthetic energy conservation. II. Photophosphoryiation in liposomes containing photosystem-l reaction center and chloroplast coupling-factor complex. Eur J Biochem 111 540.

Fig. 14. (A) Schematic representation of the steps for the creation of an artificiai electrochemioai-potentiai difference, across the thylakoid membrane in a chioropiast suspension (B) Piot of ATP yieid in mmoi ATP/moi Chi vs. reaction time at a fixed ApH of 3.2 and three A t values of 5, 44 and 60 mV the initial slopes representing ATP synthesis rates in mmol ATP/mol Chl s (C) Rate of ATP synthesis in ATP/CFg F, per sec plotted for reconstituted CF -F,-liposomes energized by ApH and A F. Figure source (B) GrSber, Junesch and Schatz (1984) Kinetics of proton-transport-coupied ATP synthesis in chioropiasts Activities oftheATPase by an artifi-ciaiiy generated ApH and A F. Ber Bunsenges Phys Chem 88 601 (C) Schmidt and Graber (1987) The rate of ATP synthesis cataiyzed by reconstituted CF -F -iiposome dependence on ApH and A F. Biochim Biophys Acta 890 393.

Fig. 24. A schematic representation of light-induced proton translocation and ATP synthesis in liposomes reconstituted by incorporating bacteriorhodopsin and ATP synthase.

Figure 1 Principle of LTD. Schematic representation of heat and dye distribution during laser-targeted drug delivery following a laser pulse in an eye with CNV. The energy deposited in the tissues causes heating, as illustrated by the oval. The bolus of dye released in the CNV vessels is retained longer than that in the choriocapillaris because of slower flow within the CNV. The CNV and the tissues in its immediate vicinity reach the releasing temperature of the liposomes, but the retinal vessels do not. Abbreviations. LTD, laser-targeted delivery CNV, choroidal neovascularization. Source From Ref. 4, Figure 1.

Fig. 6.35. Schematic representation of possibie modes of interaction of iiposomes with ceiis that iead to intraceiiuiar deiivery. Liposomes can enter the ceii by iocai destabiiization of piasma membrane or fusion (a) or endocytosis (b). The reieases of DNA by fusion is stiii not ciear (c or d). The reieased DNA or cationic iiposome-DNA compiexes reach into the nucieus (e), and gene expression occurs (f). (Adapted from Singhai A, Huang L.Gene transfer in mammaiian ceiis using iiposomes as carriers. In Wolff JA, ed. Gene Therapeutics. Boston Birkhauser, 1994 118 with permission.)...

FIGURE 58.4 Schematic representation of the mechanisms of liposome formation (a) film-forming method and (b) organic solvent injection method. (From Zhang, K. et al., Powder TechnoL, 190(3), 39355, 2009.)... 

Fig. 19 Left) Schematic representation of the proposed mechanism for topological changes in dioleoyl phosphoethanolamine (DOPE) based liposomal membranes upon ultrasound irradiation. Right) (a) Giant DOPE-based unilamellar vesicle, before sonication, which shows an inhomogeneous membrane DOPE-rich domains of negative curvature are marked in red, embedded in zones rich in dioleoyl phosphocholine (DOPC) of zero mean curvature, (b) Illustration of shape changes upon ultrasound stimuli. Reproduced with permission from [99]. Copyright 2014 The Royal Society of Chemistry...

Some surfactants self-assemble into closed bilayers called vesicles (or liposomes when formed from phospholipids). Vesicles are often spherical but can take other shapes and can be unilamellar or multilamellar. In contradistinction to micelles, vesicles may not be thermodynamically stable. Another important difference between vesicles and micelles is that vesicles have an inside that encloses some of the aqueous phase and an outside. The existence of a critical vesiculation concentration, above which some surfactants would form vesicles, is sometimes mentioned. This is probably incorrect. At very low concentrations, surfactants always start forming micelles that may turn into vesicles ct higher concentrations. Given in Fig. I are schematic representations of a micelle and a vesicle, both o f spherical shape. 

Fig. 2 Schematic of liposome loaded with a tri-fusion reporter gene (TF). (A) Schematic representation of the tri-fusion reporter gene (TF) containing Renila luciferase (Rluc), red fluorescent protein (RFP) and HSV-ttk driven by a CMV promoter. (B) Schematic representation of liposome nanoparticle and liposome-DNA coupling reaction. Therapeutic liposomes were loaded with Rluc-RFP-ttk gene. (C) The expression of TF transgene was tracked and analyzed by imaging and immunofluorescence. Imaging of Renilla luciferase intensity from one representative BALB/c mouse [39].

Ci8Na/200 and PNIPAM-Ci8Py/200 in water (left) and with liposomes of DMPC (right) and schematic representations of the interactions 25°C, Xexc = 290 nm. 

Figure n 38. Schematic representation of a multilamellar vesicle (MLV) or liposome and an unilamellar vesicle (ULV). 

Figure 23.9 Schematic representation of the operation of a liposomal immuno-diagnostic assay for the detection of folic acid.

Strength O.6., as well as the schematic representation of the liposome at each time. First, liposomes condensed into a non-spherical shape at 24 min after exchange, and then showed an outward protrusion of the liposome membrane at 30 min. This deformation is due to an osmotic pressure difference across the liposome membrane because of a difference in the MES concentration through the semipermeability liposome membrane. 

Figure 46.2 Schematic representation of various types of targeted nanoparticle platforms proposed for multimodal molecular imaging applications, (a) CLIO, (b) MCIO, (c) SPIO, (d) micelle, (e) liposome, (f) emulsion, (g) Qdot micelle, and (h) microbubble. Reproduced from Reference 40 with permission fiom the publisher.

Fig. 5.1 Schematic representation of the simplicity of a PC/cholesterol liposome (a) in comparison to a complex biological membrane (b)...

Fig.8 Schematic representation of unilamellar liposomes (i.e. consisting of one bilayer).

Fig. 20 Schematic representation of ATP synthetase incorporated into a partially polymerized liposome.

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