The thesis entitled “Evolution of New Lipids and Molecular Gelators: Syntheses, Aggregation Properties and Applications” elucidates the design, synthesis, aggregation properties and application of new lipids based on α-tocopheryl backbone and also with triazacyclononane (TACN) moiety. This thesis also elucidates the synthesis and aggregation properties of molecular gelators based on pyrene-pentapeptide and naphthalene diimide (NDI) moiety. The work has been divided into five chapters. Chapter 1: Introduction: Self-assembled Molecular Aggregates and their Potential Applications This chapter describes the importance of different self-assemble mainly lipids and molecular gelator. Lipids mediated gene delivery, drug delivery and metal ion induced interaction are discussed. For liposomal gene delivery here we mainly describe example of cationic gemini lipids. This chapter also gives a comprehensive account of the research towards the development of novel liposomal drug delivery containing tocopheryl backbone. It also includes the utilization of liposome which could coordinate with metal ions and their interaction with different biological analyte. Here we also discuss a wide range of molecular gelator mainly based on NDI and amino acid or peptide. Chapter 2A: Physicochemical Characterization of Bilayer Membranes Derived from (±) α-Tocopherol Based Gemini Lipids and their Interaction with plasmid-DNA and Phosphatidylcholine Bilayers In this sub-chapter we discuss the membrane formation and aggregation properties of a series of (±) α-tocopherol based cationic gemini lipids (Figure 1) varying polymethylene spacer length (TnS; n = 3, 4, 5, 6, 8 and 12) are studied extensively while comparing with corresponding properties of monomeric counterpart (TM). Liposomal suspensions of all cationic lipids are characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential measurements and small angle x-ray diffraction studies. Aggregation properties of the gemini lipids are highly dependent on the spacer length and were significantly distinct from that of monomeric lipid (TM). Figure 1. Molecular structures of (±) α-tocopherol based cationic monomeric and six gemini lipids that differ in polymethylene spacer length. Stable monolayer formation at air water interface formation of each amphiphile is studied by Langmuir film balance technique. Interaction of liposome with plasmid DNA is studied by ethidium bromide (EB) intercalation assay. Micellar sodium dodecyl sulphate (SDS) mediated release of the plasmid DNA from various pre-formed lipoplex is also studied. Structural transformation of pDNA upon complexation with liposome is characterized by circular dichroism (CD) spectroscopy. Interaction of all tocopheryl lipids with a model phospholipid, L-α-dipalmitoyl phosphatidylcholine (DPPC) derived vesicles is thoroughly examined by differential scanning calorimetry (DSC) and DPH fluorescence anisotropy measurements. Succinctly, we perform a detailed physicochemical characterization on cationic monomeric and gemini lipids bearing tocopherol as their hydrophobic backbone. Chapter 2B: Physicochemical Characterization of Bilayer Membranes Derived from (±) α-Tocopherol Based Gemini Lipids Containing Hydroxyethyl Functionality in the Headgroups and their Interaction with plasmid-DNA and Phosphatidylcholine Bilayers This sub-chapter describes the synthesis and aggregation properties of series of tocopheryl-based monomeric and gemini cationic lipids with hydroxyethyl functionality (Figure 2) in the headgroup region. Gemini lipids of this given series differ in their polymethylene spacer -(CH2)n- chain lengths between cationic headgroups. All monomeric and gemini lipids are found to generate stable suspensions in aqueous media. Average hydrodynamic diameter and surface charge of liposome are characterized by DLS and zeta potential measurements. Atomic force microscopy and transmission electron microscopic studies show that all lipids form vesicular Figure 2. Molecular structures of (±) α-tocopherol based cationic monomeric and five new lipids with hydroxyethyl functionality in the headgroups that differ in polymethylene spacer length aggregates in aqueous media. XRD studies with the cast films of lipids reveal interdigitated bilayer arrangement of liposome. pDNA binding and release studies show that the interactions between gemini lipids and DNA depend upon the nature of head group as well as the length of the spacer between cationic head groups. Circular Dichroism (CD) spectra of lipoplex are measured to characterize structural transformation of pDNA upon complexation with liposome. DPH anisotropy and DSC studies of the DPPC-cationic lipid co-aggregates show that ~20 mol-% of of the tocopheryl gemini lipids is enough to abolish phase transition of DPPC membranes whereas more than 20 mol-% is required in case of their monomeric counterparts. Furthermore thermotropic properties of co-aggregates depend upon the length of the spacer of gemini lipid included in the mixture. Chapter 2C: Transfection Efficacies of α-Tocopherol Based Cationic Gemini Lipids with Hydroxyethyl Containing Headgroups. In this sub-chapter, we demonstrate transfection efficiency of five α-tocopheryl gemini lipid with hydroxyethyl containing headgroups (Figure 3). Co-liposomal formulations with helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) form highly stable formulations in water. Co-liposomal formulations with high molar ratio of DOPE (1.5:1 and 2:1) show higher transfection efficiency than liposome with low DOPE content liposome. Co-liposome of gemini lipids with longer spacer (n = 8 and 12) have higher level of luciferase expression in HepG2 cell line. In A549 and MCF-7 cell lines also co-liposomes of TH8S (2:1) are proved to be better than other co-liposome. N/P ratios of highest transfection are 1-1.5. These formulations are more potent than L2K in all three cancer cell line. The comparison with gemini lipid (T8T) without Figure 3. Molecular structures of (±) α-tocopherol based cationic gemini lipids that differ in polymethylene spacer length and helper lipid DOPE. hydroxylethyl group also proves the importance of hydroxyethyl functionalities. High serum stability of DOPE-gemini lipid formulation is attributed to tocopherol backbone and also hydroxyethyl functionalities. Circular dichroism data also show that lipoplex of DOPE-TH8S (2:1) have different conformation than the other. Relatively moderate binding efficiency and easy release of pDNA is also observed with DOPE-TH8S (2:1) in the EB-displacement assay which could be plausible reason for high transfection efficiency. Chapter 2D: Reduction Responsive Nanoliposomes of α-Tocopheryl-Lipoic Acid Conjugate for Efficacious Drug Delivery to Sensitive and Resistant Cancer Cells In this sub-chapter, we present lipid conjugates derived from biologically relevant molecules, i.e., tocopherol and lipoic acid (Figure 4). These conjugates (TL1 and TL2) are able to form stable nanoliposomes (~100 nm) that respond to the reducing environment of cells as shown by the treatments of 1,4-Dithiothreitol (DTT) and Glutathione (GSH). Figure 4. Molecular structures of tocopheryl-lipoic acid conjugates, TL1 and TL2 Nanoliposomes could efficiently load the drug (DOX) molecules and release them in response to the stimulus. Nanoliposomes are stable enough in the presence of serum and could deliver DOX inside drug sensitive and drug resistant cells in an efficient manner that is even better than the drug alone treatments as shown by means of flow cytometry and confocal microscopy analysis. DOX loaded nanoliposomal formulations show relatively less cell viability counts than those drug alone treatments. Chapter 3A: Interaction of Nickel (II) and mida ole it Triazacyclononane Modified Chelator Amphiphiles: A Potential Substrate for Immobilization of His-tag Protein on Hydrophilic Surface This sub-chapter describes two chelator amphiphiles based on 1, 4, 7-traiazaclonone (TACN) (Figure 5). These compounds could bind efficiently Ni2+ ion. Self-assemble of these amphiphiles form vesicular aggregates. Their packing properties of these amphiphiles are influence by Ni2+ and imidazole. Also influence of Ni2+ and imidazole in Langmuir monolayer isotherm of these amphiphiles at air-water interface are also studied. Figure 5. Molecular structures of TACNA chelator amphiphiles. These studies show the newly synthesized amphiphiles could immobilize histidine tagged protein on both bilayer and monolayer surface. One of these compounds with Ni2+ (C16TACNA-Ni2+) is used to transfer a His-tagged protein nucleolin on hydrophilicobic glass surface by Langmuir-Blodgett transfer technique. So, these compounds with Ni2+ could be very useful to attach different His-tagged protein or polypeptide of interest on the bilayer (liposome) or monolayer surface. Chapter 3B: Supramolecular Hosts for Enhancing the Selectivity of TACN Based Probes towards Copper (II): Differential Output Signals for Cysteine and Histidine In this sub-chapter, we have developed a new amphipathic probe compound 1 having TACN as the binding site and dansyl as signaling moiety (Figure 6). As TACN is known for its’ unspecific interaction with multiple ions, the probe shows response with most of the transition metal ions. However, incorporation into different supramolecular hosts (like micelle and vesicles) drastically improves the selectivity of compound 1 towards Cu2+ (diminution of bright green fluorescence) in water. Then we Figure 6. Molecular structures of dansylated TACN chelator amphiphiles. have also employed the Cu2+ complex of compound 1 for selective estimation of amino acids. Addition of cysteine regains the green emission of compound while histidine exhibits blue intense emission upon formation of ternary conjugate. Chapter 4: Transforming a β-Sheet Pyrenylated-VPGKG Sequence into pH Tolerent, Thixotropic Hydrogel by Arene-Perfluoroarene Interactions and Visualized Sensing of Calcium (II) Ion In this chapter we discuss self-assembly studies of a novel thermoresponsive, lipidated, pyrene-appended peptide, PyP (Figure 7). Size of the vesicular aggregates of the β-sheet forming peptide, PyP, strongly depends on the temperature of the solution in water. Further pyrene-octafluoronaphthalene (OFN) pair has been used as supramolecular synthon to induce hydrogelation of PyP in presence of equimolar amount of OFN via complementary quadrupole-quadrupole interactions. The gel shows excellent pH tolerant as well as thixotropic behavior. Detailed studies suggested the lamellar packing of the gelator in a right-handed helical fashion yielded vesicular aggregates. The sticky vesicles form gel via inter- Figure 7. Molecular structure of the Pyrenylated-VPGKG peptide (PyP) and octafluoronapthalene (OFN). Ca2+ ion reinforces the mechanical strength and also reduces the critical gelator concentration of the native gel through coordination with the free -COO- group of the gelator. Therefore, this present system could be used as a visualized sensor of Ca2+ ion. Chapter 5: First Report of Naphthalenediimide Based Metallo(organo)gel In this chapter, we have demonstrated synthesis of a novel asymmetric bolaamphiphilic (Figure 8). NDI derivative is capable of self assemble into stable gel in EtOH. Detailed studies reveal the gelator molecule of 1 adopt a parallel alignment in the lamellae during self-aggregation as nanoscopic spherical assemblies. In addition, dried gel of 1 shows nematic liquid crystalline phase. Further, we synthesize a novel metal-ligand discrete complex 2 in a nearly quantitative yield by reacting equimolar amount of 1 and PdCl2(PhCN)2. Figure 8. NDI derivative, 1, and its discrete metal complex 2. Complex 2 has been found to yield stable gel in dichloromethane (DCM) or chloroform (CHCl3) through the formation of high aspect ratio fibers. ROESY NMR experiment of Complex 2 has been found to yield stable gel in dichloromethane (DCM) or chloroform (CHCl3) through the formation of high aspect ratio fibers. ROESY NMR experiment of

À cause du renforcement des réglementations et de l'évolution de l'opinion publique, les tensioactifs issus de la biomasse sont de plus en plus étudiés. À l'heure actuelle, la diversité structurelle de ces composés reste faible et est bien loin de concurrencer les produits issus des ressources fossiles. Pour enrichir les structures disponibles, nous nous sommes intéressés aux composés furaniques, comme le 2,5-diformylfurane (DFF), synthétisés à partir des sucres. Dans cette optique, nous avons tout d'abord généralisé et optimisé une méthode de synthèse originale du DFF. Ce procédé permet de s'affranchir de l'usage des métaux de transition ou des liquides ioniques. Le système utilisé pour convertir des substrats complexes, comme les amidons, repose sur l'action combinée d'acide borique, de bromure de sodium et d'acide formique dans le diméthylsulfoxyde (DMSO). L'acide borique joue un rôle majeur dans ce système puisqu'il est impliqué dans les étapes de déconstruction de la biomasse, d'isomérisation des unités glucose en fructose et dans la formation du HMF. Le bromure de sodium dans le DMSO permet l'oxydation sélective en DFF alors que l'acide formique accélère cette étape. Dans ces conditions, nous avons été capables de produire du DFF à une échelle de plusieurs dizaines de grammes avec des rendements de l'ordre de 20 %. Après l'optimisation de la synthèse, nous avons également étudié le mécanisme d'oxydation impliqué dans cette transformation. La seconde partie de l'étude a été la transformation du DFF en composés tensioactifs. Au terme d'une synthèse de cinq étapes, nous avons obtenu des produits zwitterioniques originaux avec des rendements d'environ 50 %. Ces composés de type gemini issus de la transformation des sucres montrent de bonnes propriétés comme des concentrations micellaires critiques très faibles comparables aux autres tensioactifs gemini déjà étudiés. / Due to stricter reglementations and the development of public opinion, surfactants synthesized from biomass are becoming increasingly interesting. However, the structural diversity of these compounds is still too low to compete with the products synthesized from fossil resources. In order to increase the diversity of available structures, we focused on common furanic building blocks, such as 2,5-diformylfuran (DFF), which are synthesized form carbohydrates. Firstly, we optimized a new and innovative synthesis of DFF. This method allowed us to use neither transition metal catalysts nor ionic liquids. The system we used to convert complex substrates, such as starch, relies on boric acid, sodium bromide and formic acid in dimethylsulfoxide (DMSO). Boric acid plays a key role in this system. It is involved in the biomass deconstruction, glucose to fructose isomerization and HMF formation. Sodium bromide in DMSO promotes the oxidation to DFF and formic acid increases the rate of this step. By using this system, we were able to synthesized DFF from glucose at multigram scale with 20% yield. After optimization of the synthesis, we investigated the oxidation mechanism. The second part of this work was focused on the conversion of DFF into new gemini surfactants. At the end of a five steps transformation, zwitterionic products were obtained with 50% yield. These gemini type compounds shows interesting properties such as very low critical micellar concentration which are similar to these measured for already reported gemini surfactants.

The thesis entitled “Novel Cationic Gemini Lipids, Click Chemistry Based Adducts and Amphiphile-Capped Silver Nanostructures: Synthesis, Aggregation and Biological Properties” elucidates the design, synthesis, aggregation and gene transfection properties of novel gemini cationic lipids based on cholesterol and pseudoglyceryl backbone, and click chemistry based adducts. This thesis also elucidates the synthesis and aggregation properties of silver nanoparticles loaded cationic liposomes and silver nanorods stabilized by micellar solutions of gemini surfactants. The work has been divided into six chapters. Chapter 1: Introduction: Membrane Formation from Cholesterol-based Cationic Lipids and their use as Non-Viral Gene Delivery Agents This chapter describes the importance of cholesterol in biological membranes, the aggregation properties of cholesterol-based cationic lipids and their interactions with phospholipid membranes. This chapter also gives a comprehensive account of the research towards the development of novel cationic cholesterol-based monomeric and gemini lipids. It also reviews the utilization of cholesterol-based cationic monomeric and gemini lipids in gene transfection properties. Chapter 2A: Effect of Hydroxyl group on the Cationic Headgroups of Cholesterol-based Gemini Lipids on their Aggregation, DNA Binding Properties and Interaction with Phospholipid Membranes This chapter describes the syntheses and aggregation properties of two series of cholesterol-based monomeric and gemini cationic lipids with and without hydroxyl functionality (Figure 1). The gemini lipids of a given series differ in their spacer polymethylene -(CH2)n- chain lengths between the cationic headgroups. Figure 1. Molecular structures of non-hydroxylated and hydroxylated cationic cholesterol-based gemini lipids and their monomeric counterparts. All monomeric and gemini lipids were found to generate stable suspensions in aqueous media. Electron microscopic studies showed that all the lipids form vesicular aggregates in aqueous media. The structures seen under TEM for the non-hydroxylated series of monomeric (C-M) and gemini lipids are of variable sizes, they appeared like separated vesicular aggregates. For the hydroxylated series of lipids, however, both the monomeric lipid aggregates (CH-M) and aggregates of their gemini counterparts were found to be ‘connected’ with each other to form elongated chain of aggregates of different length scales. XRD studies with the cast films of lipids revealed that the monomeric lipids of either series have higher bilayer width than the corresponding gemini lipids. Incorporation of the -(CH2)n- spacer units at the head group level joining the two monomeric units lowered the bilayer thicknesses of both series of the lipid aggregates. Thus the monomeric lipids (C-M and CH-M) appear to form nearly regular bilayer type arrangements whereas gemini lipids form interdigited and tilted bilayer arrangements in their aggregates. Calorimetry studies of the coaggregates showed that ~10 mol-% of most of the cholesterol gemini lipids is enough to abolish the phase transition of DPPC membranes whereas more than 10 mol-% is required in case of their monomeric counterparts. Further these thermotropic properties depend upon the length of the spacer of the gemini lipid included in the mixture. We have observed greater quenching of the thermal phase transition of DPPC membranes with 10 mol-% of C-M as compared to CH-M doped liposomes. At 10 mol-% of all the cationic lipid doped DPPC covesicles, only CG-3 doped liposomes showed an observable transition temperature. Maximum broadening of the DPPC transition peak was observed in the case of the gemini lipids, CHG-6 and CHG-12. DNA binding and release studies show that the interactions between gemini lipids and DNA depend upon the nature of the head group as well as the length of the spacer between the cationic head groups. For the non-hydroxylated cholesterol-based cationic lipid series, the monomeric liposomes of C-M facilitates the dissociation of EB from the EB-DNA complex to an extent of 93% at a maximum lipid:DNA ratio of 3.0 whereas the liposomes of CG-4 and CG-12 showed the lowest extent of maximum EB exclusion (~74%) from the EB-DNA complex at lipid:DNA ratio of 3.0. For hydroxylated cholesterol-based cationic lipid series, the monomeric liposomes of CH-M facilitate the dissociation of EB from the intercalated EB-DNA complex to an extent of 81 % whereas the liposomes of CHG-3 showed the minimum binding to DNA. Thus the two monomeric liposomes C-M and CH-M were the more efficient formulations that allow dissociation of DNA from the corresponding lipoplexes. These findings have important being in their gene transfection activity compared their respective gemini lipid counterparts. Chapter 2B: Novel Cholesterol-based Cationic Gemini Lipids possessing Hydroxyethyl group on the Headgroup: Transfection Efficacy and Cell Toxicity Properties This chapter describes the transfection efficacy and cell toxicity properties of five cholesterol based gemini cationic lipids possessing hydroxyethyl functionality on each head group, which differ in the length of the polymethylene spacer [-(CH2)n-] chain (Figure 2). These gemini lipids are important to gene delivery processes as they possess pre-optimized molecular features, e.g., cholesterol backbone, ether linkage and a variable spacer chain between both the headgroups of the gemini lipids. Cationic liposomes were prepared from each of these lipids individually and as a mixture of individual cationic gemini lipid and 1,2-dioleoylphosphatidylethanolamine (DOPE). The gemini lipid with a hydroxyethylated headgroup and a -(CH2)5- spacer, CHG-5 showed the highest transfection activity at N/P (lipid/DNA) ratio of 0.5 and lipid:DOPE molar ratio of 2. Upon comparison of the relevant parameters, e.g., % transfected cells, the amount of DNA transfected to each cell and % cell viability all together against LipofectAMINE 2000, one of the most potent commercially available transfecting agents, the optimized lipid formulation based on CHG-5/DOPE was found to be comparable. In terms of its ability to induce gene-transfer in presence of serum and shelf-life CHG-5/DOPE liposome was found to be better than its commercial counterpart. Recording of confocal images confirmed that in presence of 10% serum using 1.2 µg DNA per well and lipid:DOPE ratio of 1:4 and N/P charge ratio of 0.75, CHG-5 is better than LipofectAMINE 2000. These properties render them to be reagents of practical value for various gene delivery applications. Figure 2. Molecular structures of cholesterol-based cationic monomeric lipid and gemini lipids possessing hydroxyethyl group on the headgroup synthesized. Chapter 3: Bilayer Membrane and Stable Monolayer Forming Properties of Cationic Pseudoglyceryl Gemini Lipids having Polymethylene Spacers and Oxyethylene Linkages This chapter describes the synthesis of five new cationic pseudoglyceryl gemini lipid versions of their monomeric counterpart (Figure 3). Each cationic lipid aggregate in aqueous media was found to form vesicular structures as evidenced from the negatively stained TEM experiments and DLS measurements. XRD experiments with their cast films of aqueous dispersions revealed that introduction of the polymethylene -(CH2)n-spacer chain joining the two monomers decreased the bilayer widths of the gemini lipid aggregates. The inter-lipidic packing and the hydration of the lipid vesicles were examined using fluorescence anisotropy and generalized polarization measurements using membrane-soluble probes, DPH and Paldan respectively. Fluorescence anisotropy measurements showed that the aggregates of lipid 2c with -(CH2)5- spacer chain were highly packed and ordered in the vesicular aggregates than that of the other cationic lipid aggregates in the series. Paldan hydration studies showed that incorporation of the polymethylene -(CH2)n- spacer chains joining two monomeric units lowered the hydration of the gemini lipid aggregates in the solid gel state. Each of these cationic lipid aggregates showed sharp transition temperatures (Tm) as observed from differential scanning calorimetric studies. DSC studies further revealed that the incorporation of oxyethylene group at the linker region of cationic pseudoglyceryl gemini lipid 2a with (CH2)3- spacer chain length lowered the thermotropic phase transition temperature (Tm) of the aggregates in aqueous media when compared with the corresponding gemini analogue without oxyethylene linkages. Langmuir film balance studies showed that each cationic gemini lipid and their monomeric counterpart were able to form stable monolayers at the air-water interphase. We observed that the mean molecular area (collapse area) of each of the cationic lipid obtained from the Langmuir monolayer studies increased with increase in the spacer chain lengths. Figure 3. Molecular structures of the cationic pseudoglyceryl gemini lipids and their monomeric counterpart. Chapter 4: Vesicle and Stable Monolayer Formation from Simple ‘Click’ Chemistry Adducts in Water This chapter describes successful use of Cu(I) catalyzed “Click Chemistry” for the syntheses of a series of hitherto unknown amphiphilic adducts (M1, M2, D1 and T1) which on dispersal in water afforded vesicular aggregates as evidenced from dye entrapment, TEM, SEM, AFM and DLS studies (Figure 4). Figure 4. Molecular structures of triazole based adducts. XRD experiments with their cast films of aqueous suspensions indicate the formation of a tilted bilayer arrangement for the aggregates of M1 whereas regular bilayer structures are predominant for the aggregates derived from M2, D1 and T1. Measurement of pKa values using UV-Vis spectroscopy showed that the aggregates of monomeric click adducts (M1 and M2) possess less pKa value than that of the aggregates of dimeric (D1) and tetrameric (T1) analogues and the values lie within the range of 2.8-3.2. The hydrodynamic diameter of the aggregates of each click adduct increased with decrease in the pH of the media. Thus, the protonation of the triazole groups in the aggregates of each click adduct increased the hydrodynamic diameter. Dye entrapment studies showed that each click chemistry based adduct formed closed vesicular aggregates with inner aqueous compartment in aqueous media. The temperature induced order-to-disorder transitions of the aggregates and the accompanying changes in hydration were examined using high sensitive DSC, fluorescence anisotropy and generalized polarization measurements using a membranesoluble probe, DPH and Paldan respectively. In the solid state, M1 remains as the most hydrated species whereas in the fluidized phase, D1 maintains as the most hydrated aggregate. Clearly simple variation in the adduct molecular architecture bring about significant changes in their packing in aggregates and also the hydration of the resulting vesicles. Langmuir monolayer studies confirmed that these click adducts do form stable monolayers as well on water subphase at the air-water interface. We also calculated the mean molecular areas from the Langmuir monolayer studies and as perhaps expected the adduct T1 has the highest head group area. Thus click chemistry based simple triazole adducts, which can be very easily prepared, are good candidates for further investigations involving syntheses of novel self-assembling structures. Chapter 5: Lipid Mediated Synthesis of Silver Nanoparticles, their Physical Characterizations and DNA Binding Abilities In this chapter, work on the Ag-NP (silver nanoparticle) loaded liposomes preparation using four cationic lipids (1-4) in which the Ag-NPs were entrapped within lipid bilayer has been described. A novel method was developed to synthesize the Ag-NPs where the lipid itself capped and stabilized the Ag-NPs. Consequently there was no need of inclusion of any other capping agents like citrate. Confocal microscopy confirmed that these Ag-nanoparticles are fluorescent in character. It was also demonstrated that silver nanoparticles are indeed entrapped in lipid bilayer with transmission electron microscopy (TEM). DLS experiments provided information about the hydrodynamic diameter of the lipid vesicles which increased with the increase in Ag concentrations. This could be due to the ‘loosening’ of the lipid packing in vesicles. Zeta potential measurements showed that the zeta potential value decreased with the increase in the concentration of Ag-NPs in the cationic lipid vesicles. XRD studies with the cast films of the lipid or Ag-NP loaded lipid suspensions revealed that when the Ag-NPs get entrapped into the bilayer of the multilamellar vesicles of the lipid in the aqueous media, the unit bilayer thickness of the aggregates increased. Paldan experiments showed that with the incorporation of Ag-NPs in the lipid vesicles, the hydration of the lipid vesicles increased to a significant extent but the phase transition temperatures remained practically unaltered for all the lipids. Fluorescence anisotropy experiments revealed that the hydrocarbon chain packing of the lipid vesicles ‘loosens’ with the incorporation of Ag-NPs. Ag-NP loaded liposomes showed enhanced DNA binding ability and also the presence of Ag-NPs in cationic liposomes induced the release of DNA from silver nanoparticle-loaded lipoplexes more effectively. Figure 5. Molecular structures of the cationic lipids mentioned in the present chapter. Chapter 6: Dependence of Spacer Chain Lengths in the Synthesis of Ag-Nanorods in Gemini Cationic Surfactant Micelles Figure 6. Chemical structures of cationic gemini surfactants. This chapter describes the synthesis of Ag-nanospecies by seed-mediated wet synthesis method using four gemini surfactants (16-2-16, 16-4-16, 16-5-16 and 16-1216) as the capping agents (Figure 6). For this, we first synthesized Ag-nanoseeds of diameter ~7 nm stabilized by trisodium citrate (as capping agent). Then the solution containing Ag-nanoseeds was used to synthesize Ag-nanorods of different aspect ratios. It was that with decreasing Ag-nanoseed concentration, the aspect ratios of Agnanorods stabilized by gemini surfactants (16-2-16 and 16-4-16) increased gradually as evidenced from TEM images. These Ag-nanoseeds and Ag-nanorods were further characterized using UV-Vis spectroscopy (to know the surface plasmon bands), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD). It was observed that when gemini surfactant 164-16 was used to stabilize Ag-nanorods, the λmax of the longitudinal band shifted more towards the red region (red-shift) as observed by UV-Vis spectroscopy when compared to that of gemini surfactant with shortest spacer, 16-2-16. Thus the gemini surfactants with shorter -(CH2)2- and -(CH2)4- spacer chains promoted the growth of Ag-nanorods in their micellar solutions whereas -(CH2)5- and -(CH2)12- spacer chains of gemini surfactants did not. So, the growth of Ag-nanorods in micellar solutions is found to be highly spacer-chain length specific. TEM micrographs revealed that the aspect ratios of Ag-nanorods stabilized by gemini surfactants 16-4-16 are larger than those compared to the Ag-nanorods stabilized by gemini surfactants 16-2-16 at a particular amount of Agnanoseed solution. TEM images of the samples containing micellar solutions of gemini surfactants 16-5-16 and 16-12-16 showed that the formation of only Ag-nanoparticles of larger sizes (compared to Ag-nanoseeds stabilized by trisodium citrate) and Agnanoprisms irrespective of the amount of Ag-nanoseed solution added. No Ag-nanorod formation in the micellar solutions of gemini surfactants 16-5-16 and 16-12-16 was observed. Gemini surfactants (16-2-16 and 16-4-16) formed bilayer arrangements to facilitate the growth and stabilization of Ag-nanorods in aqueous media where the inner layer is attached to the Ag-nanorod surface through the gemini surfactant ammonium headgroups. X-ray diffraction (XRD) studies showed that these Ag-nanorods stabilized by gemini surfactants 16-2-16 and 16-4-16 crystallized in the aqueous media via (111), (220) and (222) lattice faces. Thus this study demonstrated the way one can control structures and shapes of the silver nanoobjects using gemini surfactant micelles. (For structural formula pl refer the thesis)

This architectural study offers a solution of the Gemini High School‘s new bulding, /Brno Lesná, the bulding site number 202/9, Vaculíkova street/, and shows a new building of a house of culture with a commercial area instead of today’s school /the bulding site number 253/. The new way of car parking and strenghtened areas of this street are included. The building and pulling down of today’s houses and buildings are devided into 2 phases. In the first phase a new barrier – free school building with a possibility of accommodation and flats is designed /building site number 202/9. This bulding has got two entrances. One from the northern part is for a school and the second one in the west is for the tenants. The school area is spread among the first and the third floor (classrooms, canteen, offfices). The fourh floor is used for students‘ accommodation and for a terrace entrance. There are some flats (2+1, 3+ small kitchen, max. area 120 m) from the fifth to the tenth floors. In the underground the are some tenants‘ cellars and technological rooms for school. The renewed car parking for all the tenants, school visitors and others is provided in Vaculíkova street. After the firt phase of building the new school project will go into the second part. In that time the old school will be pulled down and a new house of culture is designed in this place. There will be restaurant, commercial area, cinema, library – café and gym – fitness. On the first floor there are a restaurant, a library – café a cinema. On the second floor there are a gym – fitness and a commercial area. Car parking for the visitors is provided in the underground - 52 cars + 4 handicapped people. The green roof of this house is designed to be comfortable to watch it from the neighbourhood and do not damage the look of this new building. To finish all this project means to create the public area between the two new buildings. A nice place for meeting people and a cultural events will be bo

Dans ce travail, nous étudions la désexcitation des noyaux formés dans les réactions 78,82Kr+40Ca à 5,5 AMeV. Le détecteur INDRA est utilisé pour mesurer les particules légères, les résidus d'évaporation et les fragments de numéro atomique 3 ≤ Z ≥ 28.Pour les deux réactions, les caractéristiques des fragments sont compatibles avec un processus de fission. Des oscillations dans les sections efficaces des fragments légers (6 ≤ Z ≥ 11) signalent la persistance d'effets de structure. L'amplitude des oscillations ne dépend pas de manière significative du nombre de neutrons du système. Les coïncidences entre particules légères et fragments suggèrent que ces fragments légers sont excités à des énergies inférieures aux seuils d'émission. Pour le système pauvre en neutrons, la section efficace des résidus d'évaporation est légèrement plus élevée et la composante de fission est ~ 25% plus importante. Pour les deux réactions, le modèle de l'état transitoire décrit raisonnablement la distribution de charge autour de la symétrie, mais surestime fortement les sections efficaces des fragments légers et n'explique pas les oscillations associées. La forme de la distribution de charge et les effets pair-impair sont reproduits de manière satisfaisante dans le cadre du système dinucléaire qui associe principalement les fragments lourds à la quasi-fission alors que les fragments légers seraient majoritairement peuplés par fusion. Ces modèles n'expliquent pas les distributions d'énergie cinétique. Cela indiquerait la nécessité de mieux décrire les grandes déformations subies par le système lors de la phase de séparation.

Research on self-assembling gemini surfactants and other amphiphiles for potential gene delivery applications in research as well as in clinical practice, and as alternatives to viral gene delivery vectors, is beginning to focus more on structureactivity relationships to address the current low gene delivery efficiencies of amphiphiles. Some underlying structureactivity relations are beginning to emerge. But, as a better understanding of the factors that govern the transfection abilities of amphiphile molecules emerges, development of improved non-viral vectors with clinical potential may also emerge.<p> The research conducted for this thesis was aimed at the design, synthesis and in vitro investigation of gemini surfactants as one of a family of novel amphiphiles being investigated for gene therapeutic applications. The properties of these compounds can be controlled as well as allowed to vary naturally. Gemini surfactant-based gene delivery systems were prepared and characterized for transfer of Luciferase plasmid (pMASIA.Luc) to both COS-7 and PAM 212 cells. Characterization was accomplished using microscopy, dynamic light scattering (DLS) and zeta (ζ) potential analysis. In vitro gene expression and toxicities were evaluated in COS-7 cell and PAM 212 keratinocyte cultures.<p> The level of in vitro transfection in general was found to correlate strongly with the structure of the gemini surfactants. Among the 12-spacer-12 surfactants, incorporation of a pH-sensitive aza (N-CH3) group, which is also steric hindrance-imposing, in the spacer chain yielded increased transfection, particularly for the 12-7N-12 surfactant. In comparison, the incorporation of the more pH-sensitive imino (N-H) group in the 12-7NH-12 surfactant yielded the highest increase in transfection among the 12-spacer-12 surfactants. The deleterious effect of steric hindrance due to the aza group is more evident when comparing the transfection efficiency of 12-5N-12 (1 × aza, higher) vs. 12-8N-12 (2 × aza, lower transfection). Another highlighted structural feature is provided by the fact that both the 12-7NH-12 and 12-7N-12 surfactants had higher transfection efficiencies than 12-5N-12 and 12-8N-12 surfactants; the first pair has trimethylene spacing, which constitutes an optimal separation between nitrogen centres, while the second pair has shorter dimethylene spacings.<p> After expanding the structure of surfactants, transfection efficiencies were found to increase in response to increase in hydrocarbon tail length, but were much lower for surfactants with no amino functional groups, those that lacked the optimal trimethylene spacing, or those having both of these limitations in the gemini surfactant spacer. The 18-7NH-18 surfactant had the highest overall transfection in both COS-7 and PAM 212 cells. Gemini surfactant-based gene delivery systems capable of adopting both polymorphic structural phases and which could undergo pH-induced structural transition demonstrated high transfection efficiencies. Gemini surfactants with both characteristics (e.g., 12-7NH-12-based complexes are both polymorphic and pH-sensitive) had higher transfection than gemini surfactants with only one (e.g., 12-3-12-based complexes are only polymorphic).<p> Overall, the m-7NH-m surfactants, the most efficient surfactants studied, had transfection efficiencies similar to that of the commercial Lipofectamine Plus reagent and imposed no higher toxicity on cells relative to the less efficient surfactants. Thus, the design of the m-7NH-m surfactants to enhance their transfection abilities also ensured that their toxicity to cells were kept minimal. Overall, the design, synthesis and in vitro transfection screening of gemini surfactant candidates has revealed that the m-7NH-m surfactants have the highest transfection efficiencies; they have emerged as suitable candidates for non-viral gene delivery in vivo or at higher levels. Gene delivery investigations for six of the gemini surfactant candidates are being reported for the first time.

Research on self-assembling gemini surfactants and other amphiphiles for potential gene delivery applications in research as well as in clinical practice, and as alternatives to viral gene delivery vectors, is beginning to focus more on structureactivity relationships to address the current low gene delivery efficiencies of amphiphiles. Some underlying structureactivity relations are beginning to emerge. But, as a better understanding of the factors that govern the transfection abilities of amphiphile molecules emerges, development of improved non-viral vectors with clinical potential may also emerge.<p> The research conducted for this thesis was aimed at the design, synthesis and in vitro investigation of gemini surfactants as one of a family of novel amphiphiles being investigated for gene therapeutic applications. The properties of these compounds can be controlled as well as allowed to vary naturally. Gemini surfactant-based gene delivery systems were prepared and characterized for transfer of Luciferase plasmid (pMASIA.Luc) to both COS-7 and PAM 212 cells. Characterization was accomplished using microscopy, dynamic light scattering (DLS) and zeta (ζ) potential analysis. In vitro gene expression and toxicities were evaluated in COS-7 cell and PAM 212 keratinocyte cultures.<p> The level of in vitro transfection in general was found to correlate strongly with the structure of the gemini surfactants. Among the 12-spacer-12 surfactants, incorporation of a pH-sensitive aza (N-CH3) group, which is also steric hindrance-imposing, in the spacer chain yielded increased transfection, particularly for the 12-7N-12 surfactant. In comparison, the incorporation of the more pH-sensitive imino (N-H) group in the 12-7NH-12 surfactant yielded the highest increase in transfection among the 12-spacer-12 surfactants. The deleterious effect of steric hindrance due to the aza group is more evident when comparing the transfection efficiency of 12-5N-12 (1 × aza, higher) vs. 12-8N-12 (2 × aza, lower transfection). Another highlighted structural feature is provided by the fact that both the 12-7NH-12 and 12-7N-12 surfactants had higher transfection efficiencies than 12-5N-12 and 12-8N-12 surfactants; the first pair has trimethylene spacing, which constitutes an optimal separation between nitrogen centres, while the second pair has shorter dimethylene spacings.<p> After expanding the structure of surfactants, transfection efficiencies were found to increase in response to increase in hydrocarbon tail length, but were much lower for surfactants with no amino functional groups, those that lacked the optimal trimethylene spacing, or those having both of these limitations in the gemini surfactant spacer. The 18-7NH-18 surfactant had the highest overall transfection in both COS-7 and PAM 212 cells. Gemini surfactant-based gene delivery systems capable of adopting both polymorphic structural phases and which could undergo pH-induced structural transition demonstrated high transfection efficiencies. Gemini surfactants with both characteristics (e.g., 12-7NH-12-based complexes are both polymorphic and pH-sensitive) had higher transfection than gemini surfactants with only one (e.g., 12-3-12-based complexes are only polymorphic).<p> Overall, the m-7NH-m surfactants, the most efficient surfactants studied, had transfection efficiencies similar to that of the commercial Lipofectamine Plus reagent and imposed no higher toxicity on cells relative to the less efficient surfactants. Thus, the design of the m-7NH-m surfactants to enhance their transfection abilities also ensured that their toxicity to cells were kept minimal. Overall, the design, synthesis and in vitro transfection screening of gemini surfactant candidates has revealed that the m-7NH-m surfactants have the highest transfection efficiencies; they have emerged as suitable candidates for non-viral gene delivery in vivo or at higher levels. Gene delivery investigations for six of the gemini surfactant candidates are being reported for the first time.