All Publications

Pazit Bar-Yosef Ofir, Ruti Govrin-Lippman, Nissim Garti, and Helga. Fueredi-Milhofer. 2004. “The Influence of Polyelectrolytes on the Formation and Phase Transformation of Amorphous Calcium Phosphate.” Crystal Growth & Design, 4, 1, Pp. 177–183. Abstract
A promising route to the fabrication of biomimetic coatings for artificial implants is the deposition of org./inorg. composite materials consisting of polyelectrolyte multilayers alternating with layers of "in situ" grown calcium phosphate crystals. To facilitate understanding of the underlying mechanisms, in this paper we discuss the influence of polyelectrolytes (PEs), polystyrene sulfonate (PSS), poly-L-lysine (PLL), and poly-L-glutamic acid (PGA) on the formation and properties of amorphous calcium phosphate (ACP) and on the nucleation and growth morphol. of the cryst. phase. PH vs. time curves revealed three distinct pptn. events, i.e., (I) pptn. of ACP, (II) secondary pptn. of a cryst. phase upon the amorphous precursor, and (III) soln.-mediated phase transformation and crystal growth. Finally, cryst. mixts. with low Ca/P molar ratios (1.39), consisting of octacalcium phosphate crystals and small amts. of apatite, were obtained. From the pH vs. time curves, the induction time, ti, preceding crystal nucleation was detd. All PEs at low concns. induced and at high concns. inhibited nucleation. The efficiency of induction increased in the order: LMw PGA equiv. HMw PGA \textless LMw PLL \textless HMw PLL \textless PSS, while the inhibition efficiency increased as LMw PLL equiv. HMw PLL \textless PSS \textless LMw PGA \textless HMw PGA. ACP particles formed in the presence of PE were smaller and less aggregated and had a higher surface charge than in the controls. All investigated PEs also inhibited growth of the cryst. phase in a nonspecific way. [on SciFinder(R)]
Eli Pinthus, Nissim Garti, Mordechai Kerzner, Yoram Sela, and Chanoch. Kotev. 2004. “Apparatus for bench scale tablet-making.”. Abstract
A tablet-making apparatus comprising die supports and guide supports fixed upon a base, plunger guides supported by the guide supports, a die having an opening through which powder may be charged, two plunger rods with opposing faces, the rods being horizontally disposed and reciprocally received within the die, and a means for activating the reciprocal movement of the plungers whereby, a tablet may be formed within the die and between the opposing plunger rod faces and then moved to a position to be gravitationally discharged. [on SciFinder(R)]
M Shevachman, A Shani, and N Garti. 2004. “Formation and investigation of microemulsions based on jojoba oil and nonionic surfactants.” Journal of the American Oil Chemists' Society, 82, 12, Pp. 79. Abstract
The properties of jojoba oil make it uniquely suited as a raw material for the cosmetics industry. Water-based, thermodynamically stable prepns. of jojoba oil are essential in many formulations. New microemulsions were prepd. based on jojoba oil and different nonionic surfactants, namely polyoxyethylene-(ethylene oxide)10-oleyl alc. (brij 96V) and ethoxylated sorbitan esters (Tweens). The effects of the surfactants and of primary alcs. as cosurfactants on the isotropic regions of the phase diagram were elucidated. It was found that, up to a certain cosurfactant chain length, the isotropic region expanded considerably as chain length increased. The size of the isotropic region also increased as a function of the ethylene glycol content of the aq. phase in microemulsions based on ethoxylated alc. but shrank when ethylene glycol was included in microemulsions prepd. with ethoxylated sorbitan esters. Secondary structural phase transitions from water-in-oil to bicontinuous and to oil-in-water structures (as detd. by measuring cond. and viscosity) were found to be related to jojoba oil content. Dynamic light scattering and small angle X-ray scattering studies established that incorporation of jojoba oil into Brij 96V micelles caused micellar transformation from elongated to spherical droplets and a decrease in the aggregation no. [on SciFinder(R)]
A Yaghmur, L de Campo, A Aserin, N Garti, and O Glatter. 2004. “Structural characterization of five-component food grade oil-in-water nonionic microemulsions.” Physical Chemistry Chemical Physics, 6, 7, Pp. 1524–1533. Abstract
The microstructure of a multi-component oil-in-water (O/W) microemulsion, to serve as a microreactor or a solubilization vehicle for food applications, has been studied using small angle scattering X-rays (SAXS) and neutron (SANS) techniques. Significant structural changes along selected aq. diln. lines in the O/W microemulsions were detd. It was found that the droplets' size is affected by increasing the water content, the oleic phase concn. and content (mixt. of R(+)-limonene and ethanol), and the nature of the surfactant (Brij 96v and Tween 60). The micellar size increases with increasing the aq. phase content in both, Brij 96v-based and Tween 60-based systems. Replacing Brij 96v by Tween 60 at const. wt. leads to larger microemulsion droplets. The increase in the surfactant concn. of these systems, as expected, leads to smaller interaction radii and to higher values of the no. particle d. Increasing ethanol content in the oleic phase (R(+)-limonene plus ethanol) decreases the effective vol. fraction, and causes redn. in the micellar size at decreasing surfactant aggregation no. as a result of its redistribution between the interfacial film and the continuous aq. phase. The SANS investigations allowed a focus on the main effects of propylene glycol (PG) and ethanol (EtOH). Both hydrophilic mols. have similar tuning properties on the microstructure. Both decrease the droplet size, render them more globular, and increase the no. of micelles. It was concluded from these results that both alcs. are partially incorporated into the interface (most of it stays in the aq. phase). The only obsd. difference in the investigated samples was that upon replacing the aq. phase partially with PG, the effective vol. fractions of the dispersed phase was decreased, while it remained unchanged when it was partially replaced by EtOH. PG and EtOH seem to influence the microstructure independently. [on SciFinder(R)]
Idit Amar, Abraham Aserin, and Nissim. Garti. 2003. “Solubilization Patterns of Lutein and Lutein Esters in Food Grade Nonionic Microemulsions.” Journal of Agricultural and Food Chemistry, 51, 16, Pp. 4775–4781. Abstract
To improve its soly. and bioavailability, lutein was solubilized in U-type food grade microemulsions based on ethoxylated sorbitan fatty acid esters, glycerol, R-(+)-limonene, and ethanol. Reverse micellar and W/O compns. solubilized both lutein and lutein ester better than an O/W microemulsion, and max. solubilization was obtained within the bicontinuous phase. Free lutein was solubilized better than the esterified lutein in the W/O microemulsions, whereas the esterified lutein was better accommodated within the O/W microemulsion. Vegetable oils decreased the solubilization of free lutein. Glycerol and alc. enhanced the solubilization of both luteins. Solubilization was surfactant-dependent in all mesophase structures, but its strongest effect was in the bicontinuous phase. [on SciFinder(R)]
Ortal Alpert, Nissim Garti, Elena Panitkova, Andrew Shipway, and Thierry. Wasserman. 2003. “Polymer-bound donor-acceptor-donor compounds and their use in a 3-dimensional optical memory.”. Abstract
The present invention is directed to a 3-dimensional optical memory comprising as an active medium a compd. capable of interconverting from one isomeric form to another by interaction of light. The compds. comprise stilbene derivs. bound to, e.g., PMMA. The compd. is bound to a polymer for achieving a uniform memory unit. [on SciFinder(R)]
Patent application expired
Shmaryahu Ezrahi, Abraham Aserin, and Nissim. Garti. 2003. “Investigation of amphiphilic systems by subzero temperature differential scanning calorimetry.Edited by K.L. Mittal Dinesh O. & Shah. Surfactant Science Series,Marcel Dekker, Inc, 109, Adsorption and Aggregation of Surfactants in Solution, Pp. 105–131. Abstract
A review. In this chapter some problems connected with the utilization of subzero temp. differential scanning calorimetry (SZT-DSC) are discussed. Among them are the detn. of hydration nos. of surfactants and org. compds., the detn. of the hydration shell thickness, the effect of alc. on the distribution of water between free and bound states in nonionic surfactant-based systems, and some considerations regarding the problem of phase sepn. of such systems in subzero temps. The significance of SZT-DSC for some novel applications is also discussed. [on SciFinder(R)]
H Furedi-Milhofer, P Bar-Yosef, R Govrin-Lippman, and N Garti. 2003. “The influence of polyelectrolytes on the formation and phase transformation of amorphous calcium phosphate.” Key Engineering Materials, 240-242, Bioceramics, Pp. 453–456. Abstract
The formation of amorphous calcium phosphate (ACP) and its transformation into octacalcium phosphate (OCP) in the presence of poly-L-glutamic acid (PGA, Mw 3000 Da and 50,000 Da), poly-L-lysine (Mw 50,000 Da) and polystyrene sulfonate (MW 70,000 Da) has been investigated. All polyelectrolytes at low concns. induced and at high concns. retarded nucleation of the cryst. ppt. In addn., the polyelectrolytes inhibited aggregation of ACP particles and growth of the cryst. phase. The intensity of the effects depended on the charge, mol. mass, and concn. of the specific polymer. [on SciFinder(R)]
H Furedi-Milhofer, Alexey Kamishny, Junko Yano, Abraham Aserin, Nissim. Garti, Helga Fueredi-Milhofer, Alexey Kamishny, Junko Yano, Abraham Aserin, and Nissim. Garti. 2003. “Crystallization of organic compounds in reversed micelles. III. Solubilization of aspartame.” Langmuir, 19, 15, Pp. 5984–5990. Abstract
The artificial sweetener, aspartame, is a dipeptide, consisting of a hydrophobic phenylalanine methyl ester entity and a hydrophilic aspartyl residue. In this work, its solubilization in five different types of water in oil (w/o) microemulsions (MEs) was investigated. The stabilizing surfactants and cosurfactants of the MEs were ME1, sodium di-2-ethylhexyl sulfosuccinate (ACT) and no cosurfactant; ME2, maleic anhydride alpha-olefin copolymer and dimethyl amino ethanol; ME 3, sucrose ester monostearate and n-butanol; ME 4, L-alpha-phosphatidylcholine and n-butanol; and ME 5, mono- and diglycerides of fatty acids and L-alpha-phosphatidylcholine. The maximum amount that could be dissolved (boundary concentration) was determined by adding powdered aspartame to a heated ME and cooling to a specified temperature under controlled conditions. The solutions that remained clear for at least 4 days were regarded as stable, and those of the stable solutions with the highest aspartame concentrations were taken as having the boundary concentrations. From the solubility data, the distribution of the aspartame molecules between the w/o interface and the water pools was calculated, and the results were correlated with the molecular structure and ionic state of the surfactant. The results show that aspartame can be solubilized in all the investigated MEs to an extent, exceeding by far its solubility in pure water, and that overall solubilization is most efficient in water/isooctane MEs stabilized with ACT (ME1). While the aspartame solubility in the water pools was comparable in all the investigated MEs, the aspartame/surfactant molar ratio at the w/o interface was found to decrease with decreasing polarity of the stabilizing surfactant at the interface. In addition to the solubilization studies, the effect of aspartame on some properties of ME1 was investigated. It was found that aspartame lowers the interfacial tension at the water/isooctane/AOT interface and, under certain conditions, stabilizes unstable mixtures of water, isooctane, and ACT. The results of small-angle X-ray scattering measurements show that the ME droplet sizes increase in the presence of aspartame molecules and their shapes change from near spherical to ellipsoidal. It was concluded that aspartame acts as a cosurfactant in water/isooctane MEs stabilized with ACT.
Nissim Garti, Idit Amar, Anan Yaghmur, Aviram Spernath, and Abraham. Aserin. 2003. “Interfacial modification and structural transitions induced by guest molecules solubilized in U-type nonionic microemulsions.” Journal of Dispersion Science and Technology, 24, 3 & 4, Pp. 397–410. Abstract
Alcs. and polyols are essential components (in addn. to the surfactant, H2O, and oil) in the formation of U-type self-assembled nano-structures, (sometimes called L-phases or U-type microemulsions). These microemulsions are characterized by large isotropic regions ranging from the oil side of the phase diagram up to the aq. corner. The isotropic oily solns. of reverse micelles (the concs.) can be dild. along some diln. lines with aq. phase to the direct micelles corner via a bicontinuous mesophases (i.e., 2 structural transitions). This diln. takes place with no phase sepns. or occurrence of liq. cryst. phases. The structural transitions were detd. by viscosity, cond., and pulsed gradient spin echo NMR (PGSE NMR), and are not visible to the eye. Two guest nutraceutical mols. (lutein and phytosterols) were solubilized, at their max. solubilization capacity, in the reversed micellar solns. (L2 phase) and were further dild. with the aq. phase to the aq. micellar corner (L1 phase). Structural transitions (for the 2 types of mol.) from H2O-in-oil to bicontinuous microstructures were induced by the guest mols. The transitions occurred at an earlier stage of diln., at a lower H2O content (20% aq. phase), than in the empty (blank) microemulsions (transitions at 30% aq. phase). The transitions from the bicontinuous microstructure to the oil-in-H2O microemulsions were retarded by the solubilizates and occurred at later diln. stage at higher aq. phase contents (50% aq. region for empty microemulsion and \textgreater60% for solubilized microemulsion). As a result, the bicontinuous isotropic region, in the presence of the guest mols., becomes much broader. It seems that the main reason for such guest-induced structural transitions is related to a significant flattening and enhanced rigidity of the interface. The guest mols. of the high mol. vol. are occupying high vol. fraction of the interface (when the solubilization is maximal). [on SciFinder(R)]
Nissim Garti, Abraham Aserin, Aviram Spernath, and Idit. Amar. 2003. “Nano-sized self-assembled structured liquids as carriers.” United States of America PCT/IL03/00498 (US20030232095A1). Abstract
The present invention relates to nano-sized self-assembled structured concs. and their use as effective suitable carriers for transferring active components into the human body. The nano-sized self-assembled concs. are composed of an aq. phase, an oil phase, a surfactant a co-solvent and co-surfactant. The formed nano-sized self-assembled structured concs. may be in the form of an aq. continuous phase, an oil continuous phase or a bicontinuous phase, and may thus be dild. to any desired extent in either oil or water maintaining their structure and the active material comprised within the nano-sized self-assembled structured concs. A micellar conc. contained lycopene, R-(+)-limonene, ethanol, and Tween 80. [on SciFinder(R)]
The patent describes novel self assembled nanostructures fully dilutable in water and with high solubilization capacity of bioactives .
Nissim Garti, Lewis G Jacobs, Branin Lane, and Imad. Zakharia. 2003. “Isotropic transparent aqueous compositions containing fat soluble vitamins, an alc. and a surfactant.” United States of America (WO2003063617A1). Abstract
Disclosed are compns. for dispersion of a fat-sol. vitamin to give a clear, stable soln. of the vitamin, the compns. comprising the vitamin, an alc., a surfactant, and water. Also disclosed are dried powder compns. comprising a fat-sol. vitamin which upon mixing with an aq. soln. form an isotropic transparent soln., said compns. comprising the vitamin, an oil, a surfactant, and a sugar alc. [on SciFinder(R)]