During the last decades, chemotherapy with cytotoxic drugs has played a significant role in cancer therapy. It’s important to develop new anticancer drugs, and drug sensitivity testing in vitro can be used to find the right diagnosis for the newly developed substances. The aim of this study was to investigate the cytotoxic activity of the new signal transduction modulators bortezomib, gefitinib and PKC412. The well-established substances cisplatin, cytarabine, doxorubicin and vincristin were investigated for comparison. The activity of the cytotoxic drugs was analysed in human tumor samples from patients with ovarian carcinoma (n=16) and lymphoma (n=15) by using the Fluorometric Microculture Cytotoxicity Assay (FMCA). The testing of cellular drug resistance by FMCA was accomplished successfully in 33 out of the 34 samples (97%). The results of this study indicated that the activity of cytotoxic drugs in tumor cells obtained from patients with ovarian carcinoma and lymphoma may be detected by the FMCA. It also suggested that bortezomib and gefitinib could represent promising agents for treatment of ovarian carcinoma and that PKC412 might be of less use for patients with this diagnose.

An ideal drug delivery system should contain an appropriate therapeutic agent and biocompatible carrier. In this study, we investigated the ability of the all-complementary self-assembling peptide AC8 in stabilizing the anticancer compound and determined the in-vitro therapeutic efficacy of the peptide-mediated anticancer drug delivery. The all-complementary peptide AC8 was designed based on the amino acid pairing principle (AAP), which contains hydrogen bonding, electrostatic, and hydrophobic interaction amino acid pairs. AAP interactions make the peptide capable of self-assembling into β-sheet structure in solution in a concentration dependent manner. Peptide solution concentration is a key parameter in controlling the nanoscale assembling of the peptide. The critical assembly concentration (CAC) of the peptide was found ~ 0.01 mg/ml by several techniques. The all-complementary peptide AC8 was found to be able to stabilize neutral state of hydrophobic anticancer compound ellipticine in aqueous solution. The formation of peptide-ellipticine complex was monitored by fluorescence spectroscopy at different mass ratios of peptide-to-ellipticine. The anticancer activity of the complexes with neutral state of ellipticine was found to show great anticancer activity against two cancer cells lines, A-549 and MCF-7. This peptide-mediated anticancer delivery system showed the induction of apoptosis on cancer cells in vitro by flow Cytometry.

An ideal drug delivery system should contain an appropriate therapeutic agent and biocompatible carrier. In this study, we investigated the ability of the all-complementary self-assembling peptide AC8 in stabilizing the anticancer compound and determined the in-vitro therapeutic efficacy of the peptide-mediated anticancer drug delivery. The all-complementary peptide AC8 was designed based on the amino acid pairing principle (AAP), which contains hydrogen bonding, electrostatic, and hydrophobic interaction amino acid pairs. AAP interactions make the peptide capable of self-assembling into β-sheet structure in solution in a concentration dependent manner. Peptide solution concentration is a key parameter in controlling the nanoscale assembling of the peptide. The critical assembly concentration (CAC) of the peptide was found ~ 0.01 mg/ml by several techniques. The all-complementary peptide AC8 was found to be able to stabilize neutral state of hydrophobic anticancer compound ellipticine in aqueous solution. The formation of peptide-ellipticine complex was monitored by fluorescence spectroscopy at different mass ratios of peptide-to-ellipticine. The anticancer activity of the complexes with neutral state of ellipticine was found to show great anticancer activity against two cancer cells lines, A-549 and MCF-7. This peptide-mediated anticancer delivery system showed the induction of apoptosis on cancer cells in vitro by flow Cytometry.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lukáš Slatinský Supervisor: Assoc. prof. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Interactions of selected anticancer drugs of the MAPK/ERK signaling pathway inhibitors group with the ABC drug transporters ABCB1 (Pgp, P-glycoprotein) and ABCG2 (BCRP, breast cancer resistance protein) are members of a transmembrane efflux ATP dependent transporter family, so called ATP-binding cassettes (ABC). Physiologicaly they are expressed in the cellular membrane and protect body tissues against potentially toxic xenobiotics including drugs. They represent also one of the tumor defense mechanisms when being able to efflux a wide variety of cytotoxic drugs out of the cancer cells leading to treatment failure. BRAF protein plays an important regulatory and signal role in MAPK/ERK pathway affecting cell division, differentiation and secretion. Mutations of BRAF lead to overactivity in MAPK/ERK pathway in many cancer cells and can be therefore targeted by anticancer therapy. Cobimetinib and dabrafenib are relatively new anticancer therapeutics inhibiting the signal pathway mentioned above and they are used in treatment of melanoma carrying the BRAF mutation. The aims of this project were to...

Metal-nucleic acid interaction studies have been gaining attention due to their biological and chemical importance. Nucleic acids are negatively charged bio-polymers and neutralization of their negative charge is essential for the stability and function. In the cells, organic positive ions (positively charged amino acids and polyamines) and some of the metal ions (e.g. Na+, K+, Mg2+...etc) neutralize the charge of nucleic acids. Whereas, interactions of some metal ions (e.g. Cd2+, Hg2+…etc) with nucleic acids destabilize the structure. The stability and conformation of nucleic acids alter due to metal interactions. Further, metal interactions with nucleic acids can bring changes in conformation of ribose, H-bonding and π-π stacking interactions. To understand the metal interactions with nucleic acids, various spectroscopic techniques are being used. However, X-ray crystallographic technique is advantageous over all other spectroscopic techniques since it gives thorough detail of coordination mode and structure. However, crystallization of large molecules like nucleic acids with metals is associated with great difficulty. In order to simplify the problem, nucleic acid constituents and derivatives have been used as model systems for metal-nucleic acid interactions. Nucleic acid constituents and derivatives are multidentate ligands. Moreover, binding mode of metal with nucleic acid constituents and derivatives depends on various factors include pH, temperature, type of metal…etc. Further, understanding of metal nucleic acid interactions can aid to develop new anticancer drugs targeting nucleic acids. For example, cisplatin is a platinum based anticancer drug, which coordinates to N(7) of guanine in DNA brings cell death. There have been several reports in literature on the complexes of metal nucleic acid constituents. However, much more research is warranted for thorough understanding of metal-nucleic acid interactions. On the other hand, nucleic acid constituents and derivatives are used extensively in anticancer drug development. Some of nucleic acid constituent derivatives, 5-Fluro uracil and 6-Mercaptopurine, are currently in use for the treatment of colorectal cancer and leukemia, respectively. Moreover, cisplatin is a platinum based anticancer drug used in the treatment of various types of cancers. However, use of these drugs for long time poses severe side effects and drug resistance. Most of the side effects are due to non bio-compatibility of drugs. To overcome problems associated with present anticancer drugs, bio-compatible metal based anticancer drug development could be an attractive and alternative strategy. To address this, in this study, we report synthesis of a number of new metal complexes of nucleic acid constituents and their derivatives and characterization by various spectroscopic techniques. Also, the interactions of Ni, Cu and Zn ions with various nucleic acid constituents and their derivatives have been elucidated by single crystal X-ray crystallography. Interestingly, Ni, Cu and Zn ions showed various coordination modes to nucleic acid constituents and their derivatives. Further, anticancer studies were carried out for all these complexes in various cancer cell lines. Several complexes showed better cytotoxicity than the well-known drug cisplatin. My thesis work is divided into five parts based on the nature of molecules. I. Synthesis, X-ray crystallographic and anticancer studies on metal (Zn/Ni) complexes of guanine (G) based nucleic acid constituents In order to understand (Zn/Ni) interactions with guanine based nucleic acid constituents and their anticancer activity, several (Zn/Ni) complexes of 5′-GMP, 5′-IMP and hypoxanthine complexes were prepared. The synthesized complexes are (1) [Zn (5′-GMP)]n.11H2O, (2) [Ni (5′-GMP)2 Na2 (μ-OH2)3 (H2O)8].2H2O, (3) [Ni (5′-IMP)2Na2 (H2O)12]n.5H2O and (4) [Ni (hx)2 (H2O)4] Cl2 [Here 5′-GMP = 5′-Guanosine Mono Phosphate, 5′-IMP = 5′-Inosine Mono Phosphate and hx = Hypoxanthine). These complexes were characterized by various spectroscopic and X-ray crystallography techniques. Complex 1: The X-ray structure revealed that zinc is coordinated to 5′-GMP through N(7) position of purine and phosphate moieties, the uncoordinated water molecules are making interesting complicated network of hydrogen bonds in the unit cell. The geometry of zinc coordination centre is distorted tetrahedral. Fascinatingly, zinc exhibited two different coordination environments. In one case, all phosphate oxygens participated in coordination with zinc. In second case, N(7) position of purine and phosphate oxygens participated in coordination with zinc. Moreover, zinc formed a coordination polymer with 5′-GMP. The conformation of ribose changed upon zinc interaction with 5′-GMP from C(3′)-endo to C(2′)-endo, these results suggest that zinc interaction with nucleic acids may change their conformation. Complex 1 is stabilized in solid state by H-bonding and π-π stacking interactions. Complex 2: In complex 2, 5′-GMP is coordinated to nickel through N(7) position of purine but phosphate moiety did not take place in coordination. Two molecules of 5′-GMP and four water molecules coordinated to nickel and formed distorted octahedral geometry. The charge of complex 2 is balanced by sodium coordination to sugar hydroxyl groups and nickel coordinated water molecules. The geometry of sodium coordination centre is distorted octahedral. The conformation of 5′-GMP is altered due to nickel interaction. Moreover, complex 2 is stabilized in solid state by H-bonding and π-π stacking interactions. Complex 3: Nucleotide 5′-IMP also showed similar coordination modes like 5′-GMP towards nickel, where N(7) position of purine participated in coordination with nickel and phosphate moieties did not coordinate to nickel. Two molecules of 5′-IMP and four water molecules participated in coordination with nickel and formed distorted octahedral geometry. Interestingly, the charge of complex 3 is balanced by sodium coordination to sugar hydroxyl moieties. The geometry of sodium coordination centre is distorted octahedral. Moreover, nickel is forming coordination polymer with 5′-IMP. Further, nickel interactions with 5′-IMP brought changes in the conformation of ribose moiety. These results suggest that nickel interactions with nucleic acids may bring changes in their conformation. Interestingly, right hand helical structure formation is observed for complex 3 in crystal structure. Further, the chirality of complex 3 was confirmed by circular dichroism studies. Complex 3 is stabilized by both H-bonding and π-π stacking interactions in solid state. Complex 4: Surprisingly, nickel is coordinated to hypoxanthine through N(9) position of purine in acidic conditions and not through N(7) or N(3). The coordination mode of nickel with hypoxanthine is different from complexes 2 and 3. Two hypoxanthine moieties are coordinated to nickel in axial manner. The geometry of nickel coordination centre is distorted octahedral. Further, complex 4 is stabilized by H-bonding and π-π stacking interactions in solid state. Cytotoxicity studies of complexes 1-4 on various cancer cell lines revealed that complex 1 is better cytotoxic than complexes 2-4. Moreover, complex 1 exhibited comparable cytotoxicity with cisplatin on various cells lines and induced apoptotic cell death. II. Synthesis, structure elucidation and anticancer activity of copper-adeninyl complexes In order to understand copper-adenine interactions and anticancer activity, several copper complexes of adenine derivatives were prepared. Here, most of adenine derivatives used in complex preparation is known as cycline dependent kinase inhibitors. Prepared copper complexes are 1) [Cu (N6-benzyl adenineH)2Cl3 ].Cl.2H2O, 2) [Cu (2-amino-N6-benzyladenineH)2Cl3].(2-amino-N6-benzyl adenineH)2.3Cl.5H2O, 3) [Cu (α-(Purin-6-ylamino)-p-toluenesulfonamide H)2Cl4], 4) [Cu (kinetinH)2 Cl3].Cl.2H2O, 5) [Cu (N-1H-purine-6-yl-alanineH) (H2O) Cl3].H2O, 6) [(Cu (N-1H-purine-6-yl-alanineH)2Cl3).(Cu(N-1H-purine-6-yl-alanineH)Cl)2(μ-Cl)2].Cl.4H2O. All these complexes were characterized by X-ray crystallography and various spectroscopic techniques. Complex 1: Synthesis and X-ray structures of complex 1 were reported in literature. However, anticancer activity of complex 1 is not known. Therefore, it was prepared based on the reported lines to assess the anticancer activity. The anticancer activity of complex 1 was studied on various cell lines. Interestingly, complex 1 exhibited better cytotoxicity than cisplatin in MCF-7 and MDA-MB-231 cell lines. Complex 2: Ligand 2-amino-N6-benzyl adenine is coordinated to copper through N(9) of purine. In addition, two uncoordinated 2-amino-N6-benzyl adenine, three chloride and five water molecules are making it as a co-complex with uncoordinated ligands. The copper coordination centre adopted distorted trigonal bipyramidal geometry [3+2] with τ = 0.671 (α-β/60, where α, β are two greatest valence angles of coordination centre). Further, complex 2 is stabilized in solid state by both H-bonding and π-π stacking interactions. H-bonding is observed between N-H···Cl. Uncoordinated water molecules formed six-member rings with H-bonding network. The π-π stacking interactions are observed between phenyl and purine moieties. Complex 2 exhibited better cytotoxicity than 2-amino-N6-benzyl adenine and copper salt. Complex 3: Ligand α-(2-Amino purin-6-ylamino)-p-toluene sulfonamide is coordinated to copper through N(9) position and protonation is observed at N(3) position. Two molecules of α-(2-Amino purin-6-ylamino)-p-toluene sulfonamide and four chloride ions are forming a distorted octahedral geometry with copper. Complex 3 is stabilized by N-H···Cl and N-H···O H-bonding. Further, complex 3 exhibited better cytotoxicity than cisplatin in U251 cells. Complex 4: Kinetin is coordinated to copper through N(9) position of purine. Protonation is observed on N(3) position and balanced the charge of complex 4. Two molecules of kinetin and three chloride moieties are coordinated to copper and forming distorted trigonal bipyramidal geometry [3+2] with τ = 0.431. Moreover, complex 4 is stabilized by both H-bonding interactions and π-π stacking interactions. The H-bonding of complex 4 is observed between N-H···Cl and C-H···Cl. The π-π stacking interactions are observed between furanyl aromatic ring and imidazole ring of purine. Complex 4 exhibited better cytotoxicity than kinetin and copper salt. Complex 5: The N-1H-purine-6-yl-alanine is coordinated to copper through N(9) position of purine. Complex 5 crystallizes in the monoclinic space group P21 with Z=4. One molecule of N-1H-purine-6-yl-alanine, two chloride ions and one water molecule coordinated to copper. The geometry of copper coordination centre is distorted trigonal bipyramidal [3+2] with Cu(1) τ1 = 0.613 and Cu(2) τ2= 0.671. Protonation is observed on N(3) position. Complex 5 is stabilized by both H-bonding and π-π stacking interactions. The H-bonding of complex 5 is observed between N-H···Cl and C-H···Cl. The π-π stacking interactions are observed between imidazole moieties. Moreover, complex 5 exhibited better cytotoxicity than N-1H-purine-6-yl-alanine and copper salt. Complex 6: Complex 6 is a co-complex, where two different complexes are co-crystallized. The crystal structure of complex 6 indicate that geometry of Cu(1) and Cu(2) coordination centre are distorted trigonal bipyramidal [3+2] with τ1 = 0.3261 and τ2 = 0.8, respectively. Two molecules of N-1H-purine-6-yl-alanineH are coordinated to Cu(2) through N(9) position of purine. The N-1H-purine-6-yl-alanineH ligands are arranged in geometry in trans manner with respect to axis passing through the N(9) atom and copper. Whereas, in second co-complex two N-1H-purine-6-yl-alanineH are coordinated to Cu(1) through N(9) and N(3) position of purine. Both Cl(1) and Cl(3) coordinated to copper are forming a bridge between copper. In addition, one uncoordinated chloride and two water molecules are present in the unit cell. Complex 6 is stabilized in crystalline state by both H-bonding and π-π stacking interactions. Complex 6 exhibited better cytotoxicity than complex 5, N-1H-purine-6-yl-alanine and copper salt on various cell lines. III. Synthesis, structure and anticancer activity of zinc complexes of adenine derivatives In order to understand zinc interaction with adenine and their anticancer activity, several zinc complexes of adenine derivatives were prepared. The prepared complexes are (1) [Zn (N6-benzyladenineH).Cl3].2H2O, (2) [Zn2 (μ -N6-benzyladenine)2( μ-H2O)2(H2O)4].(OTf)4.H2O, (3) (N6-benzyl adenineH2) [ZnCl4].2H2O, (4) [Zn (2-Amino-N6-Benzylpurine)Cl3).2-Amino-N6-BenzylpurineH).EtOH, (5) (2-Amino-N6-(3-picoyl)purineH2)[ZnCl4].H2O, (6)(2-Amino-N6-(3-picoyl)purineH2)[ZnCl4].HCl, (7) (2-Chloro-N6-(3-picoyl) purineH2) [ZnCl4].H2O, (8) ((α-Purine-6-ylamino)-p-toluene sulfonamide H)2[ZnCl4].2HCl.2H2O. Complex 1: The N6-benzyl adenine is coordinated to zinc through nitrogen atom N(7) of purine. One molecule of N6-benzyl adenine and three chloride ions are coordinated to zinc and forming distorted tetrahedral geometry. Interestingly, the nitrogen atom N(1) of purine is protonated. Complex 1 exhibited strong H-bonding interactions between N-H···O, N-H···Cl and N-H···N. The complex 1 showed better cytotoxicity than N6-benzyl adenine and ZnCl2. Complex 2: The N6-benzyl adenine formed a dimeric complex with zinc at neutral pH. Complex 2 crystallizes in the triclinic space group P-1with Z=1. Two Zn metal centres are bridged by two molecules of N6-benzyl adenine through nitrogen atoms N(3) and N(9) of purine forming a di-nuclear complex, further two zinc centres is bridged by two water molecules and other two water molecules on the other side completing the octahedral coordination for the Zn. Complex 2 is stabilized in crystalline state by H-bonding interactions. The H-bonding of complex 2 is observed between O-H···O and N-H···O. Complex 2 exhibited better cytotoxicity than N6-benzyl adenine and ZnCl2 on various cell lines. Complex 3: The N6-benzyladenine is not coordinated to the Zn metal at acidic pH and forms an ion-pair complex. Ion-pair complex 3 crystallizes in the monoclinic space group Cc with Z=4. The protonation is observed at N(1) and N(9) atoms of N6-benzyl adenine. The positive charges on N6-benzyl adenine is neutralized by the presence of two chloride ions in [ZnCl4]2-. Alternative arrangement of cation and anion arrangement is observed in complex 3. Water channel formation is observed between cation and anion arrangement. Moreover, complex 3 is stabilized by H-bonding and π-π stacking interactions. H-bonding is observed in complex 3 between N-H···Cl, O-H···Cl and N-H···O. The π-π stacking interactions in complex 3 are observed between benzyl six-membered aromatic ring and purine six-membered rings. Complex 3 exhibited better cytotoxicity than N6-benzyl adenine and ZnCl2 in various cell lines. Complex 4: Ligand 2-amino-N6-benzyl adenine resulted in a different structure from N6-benzyl adenine with zinc. One molecule of 2-amino-N6-benzyl purine is coordinated to zinc through nitrogen atom N(7) of purine. Surprisingly, one uncoordinated positively charged 2-amino-N6-benzyl purineH is present in the asymmetric unit, which is balancing the charge of zinc complex 4. Protonation is observed on N(3A) atom. Interestingly, tautomeric proton is located on coordinated purine of N(9) atom and uncoordinated purine of N(7A) atom. Geometry of ‘Zn coordination centre’ is distorted tetrahedral. Complex 4 is stabilized by H-bonding and π-π stacking interactions. The H-bonding interaction in complex 4 is observed between N-H···O and N-H···Cl. The π-π stacking interactions are observed between five-member aromatic rings and six-membered aromatic rings. Complex 4 exhibited better cytotoxicity than 2-amino-N6-benzyl purine and ZnCl2 in various cell lines. Complex 5: 2-Amino-N6-(3-picoyl) purine forms an ion-paired complex with zinc at acidic pH. The protonation in 2-Amino-N6-(3-picoyl) purine is observed at N(3) of the purine and picolyl N(14). The positive charge of 2-Amino-N6-(3-picoyl) purine is neutralized by the presence of two chloride ions in [ZnCl4]2-. Moreover, complex 5 exhibited both H-bonding interactions and π-π stacking interactions. The H-bonding interactions are observed between N-H···Cl, N-H···N, O-H···Cl, N-H···O and C-H···N. One uncoordinated water molecule is present in unit cell, which is involved in H-bonding with both ions. The π-π stacking interactions are observed between purine five-membered rings and purine six-membered ring. Complex 5 exhibited better cytotoxicity than cisplatin in HeLa and MDA-MD-231 cells. Complex 6: 2-Amino-N6-(3-picoyl) purine formed similar structure of complex 5 in strong acidic conditions. Complex 6 exhibited both H-bonding and π-π stacking interactions. The H-bonding in complex 6 is observed between N-H···Cl and N-H···N. In complex 6, the π-π stacking interactions are observed between pyridyl six-membered rings and purine six-membered rings. Purine-Purine stacking interactions are observed between purine six-membered ring and five-membered rings. Complex 6 exhibited better cytotoxicity than cisplatin in HeLa, MCF-7, MDA-MB-231 and HeLa-Dox cells. Interestingly, complex 6 arrested (G2/M phase) cell cycle in HeLa and MCF-7 at higher concentration and induced apoptosis. Complex 7: 2-chloro-N6-(3-picoyl) purine formed ion-pair complex with zinc. The protonation in 2-chloro-N6-(3-picoyl) purine is observed on N(9) of purine and N(14) of picolyl atoms. The positive charge of 2-chloro-N6-(3-picoyl) purine is neutralized by the presence of two chloride ions in [ZnCl4]2-. Complex 7 is stabilized by both H-bonding and π-π stacking interactions. The H-bonding is observed between N-H···Cl, O-H···Cl and N-H···O in complex 7. The π-π stacking interactions are observed between pyridyl six-membered ring and six-membered ring of purine. Complex 7 exhibited better cytotoxicity than cisplatin in HeLa, MCF-7, U251 and HeLa-Dox cells. Complex 8: (α-Purine-6-ylamino)-p-toluene sulphonamide formed ion-pair complex with zinc. Ion-pair complex 8, crystallizes in the triclinic space group P-1 with Z=4. The protonation on (α-Purine-6-ylamino)-p-toluene sulfonamide is observed at N(9) and N(1) atoms of purine. The positive charge of the ligand is neutralized by two chloride ions present in [ZnCl4]2 -. The H-bonding is observed between N-H···Cl, O-H···N, N-H···O and O-H···Cl. The π-π stacking interactions are observed between benzyl rings of benzene sulfonamide moieties. Complex 8 exhibited better cytotoxicity than cisplatin in HeLa, MCF-7 and HeLa-Dox cells. Moreover, these complexes induced apoptotic cell death as revealed by Annexin V/PI assay, FACS and microscopy analysis. IV. Synthesis, structure and cytotoxicity studies of zinc complexes of uracil-1-acetic acid and N6-adeninebutyric acid To understand the zinc interactions with nucleic acid constituent derivatives and their anticancer activity, zinc complexes of uracil-1-acetic acid and N6-adeninebutyric acids were prepared. (1) [Zn (uracil-1-acetato)2 (H2O)4] and complex (2) [Zn (N6-adeninebutyric acid)2 (H2O)2]) were characterized by X-ray crystallography and various spectroscopic techniques. The X-ray structures showed acetate moiety coordination to zinc rather than purine and pyrinidine moities. The geometry of zinc coordination centre is distorted octahedral. Complexes 1 and 2 are stabilized by non-covalent interactions. Anticancer studies of these complexes showed better cytotoxicity than cisplatin in MDA-MB-231cells. V. Copper (II) complexes of 6-mercaptopurine, hypoxanthine and uracil-1-acetic acid: Synthesis, structures, antioxidant and potent anticancer activity To delineate copper interactions with purine and pyrimidine derivatives and anticancer activity, several copper complexes of 6-mercaptopurine, hypoxanthine and uracil-1-acetic acid were prepared. The prepared complexes are (1) [Cu (6-MP) (bpy) Cl2], (2) [Cu (hx) (phen) Cl2].H2O and (3) [Cu (bpy)2 (uracil-1-acetato)].6H2O)] (bpy = 2, 2′-bipyridine, phen = 1, 10-phenanthroline, 6-MP = 6-Mercapto Purine and hx = hypoxanthine). All these complexes were chracterized by various spectroscopic and X-ray diffraction techniques. Complexes 1 and 2 crystallize in the monoclinic space groups Cc and C2/c, respectively with eight molecules in the unit cell. All the complexes 1-3 adopt distorted trigonal bipyramidal geometry. Surprisingly, most potent coordination sites of sulfur in 6-MP and acetato in uracil-1-acetato did not participate in coordination with copper. In complexes 1 and 2, the N(7) position of purine and the N(3) position of pyrimidine in complex 3 are coordinated with copper. All these complexes 1-3 are stabilized by non-covalent interactions in solidstate. Anticancer studies showed better cytotoxicity for copper complexes than cisplatin, 6-meracptopurine and temozolomide in various cell lines. Interestingly, copper complexes of 6-MP and hypoxanthine showed antioxidant activity and reduced ROS level in cells. In contrast, copper complex of uracil-1-acetic acid produced ROS in cells. In contrast, copper hypoxanthine showed better cytotoxicity than cisplatin in HeLa-Dox cells. All these complexes induced apoptotic cell death. In summary, we studied the interaction of metal-nucleic acid constituents and derivatives by X-ray crystallography. We found new coordination modes for Ni, Cu and Zn towards various nucleic acid constituents and derivatives. Some of these complexes showed better cytotoxicity than well known anticncer drugs cisplatin, 6-meracptopurine and temozolomide. Complex [Cu (hx) (phen) Cl2].H2O showed better cytotoxicity than cisplatin in doxorubicin resistant (HeLa-Dox) cells. These complexes induced apoptotic cell death in various cancer cells. All in all, the results of present studies/findings could form a potential lead for the development of newer anticancer therapeutics.

Les traitements existants des métastases hépatiques du cancer colorectal montrent une efficacité insuffisante. Le projet GR5FU visait à améliorer cette efficacité et consistait à délivrer le 5-fluorouracile (5FU) dans le foie via son encapsulation dans des globules rouges (GR). Dans ce contexte, la modélisation visait à prédire la quantité de 5FU à encapsuler dans les GR pour atteindre une efficacité équivalente à celle du 5FU standard. Dans cette thèse, nous avons construit et implémenté un modèle mathématique multi-échelle qui relie l’injection du 5FU à son efficacité sur la croissance tumorale en intégrant sa pharmacocinétique et son mécanisme d’action intracellulaire. Des simulations de population de ce modèle, s’appuyant sur des paramètres de la littérature, nous ont permis (i) de reproduire des résultats cliniques montrant le pouvoir prédictif de l’enzyme Thymidylate Synthase (TS) et (ii) d’identifier deux prédicteurs potentiels de la réponse au 5FU à l’échelle d’une population virtuelle, en complément du niveau de TS : la vitesse de croissance tumorale et le métabolisme intracellulaire des pyrimidines. Nous avons également analysé, à l’aide de modèles à effets mixtes, (i) la croissance in vivo de la tumeur intra-hépatique VX2 sans traitement, tenant lieu de modèle animal de métastase hépatique, et (ii) la distribution plasmatique et hépatique du 5FU chez l’animal. Cette modélisation statistique nous a permis d’identifier les modèles décrivant des données expérimentales, d’estimer les paramètres de ces modèles et leur variabilité, et de générer une meilleure connaissance de la croissance de la tumeur VX2 et de la pharmacocinétique animale du 5FU, en particulier hépatique. Dans cette thèse, nous avons illustré comment l’intégration du métabolisme d’un médicament et de son mécanisme d’action dans un modèle global et la simulation de ce modèle à l’échelle d’une population virtuelle, constituent une approche prometteuse pour optimiser le développement d’hypothèses thérapeutiques innovantes en collaboration avec des expérimentateurs. / Existing treatments for liver metastases of colorectal cancer show a lack of efficacy. In order to improve the prognosis of patients, the GR5FU project has been implemented. It consisted in delivering the drug 5-fluorouracil (5FU) in the liver via its encapsulation in red blood cells (RBC) to increase its efficacy / toxicity ratio. In this context, the modeling aimed at predicting the amount of 5FU to encapsulate in RBC to achieve an efficacy equivalent to standard 5FU. In this thesis, we have created and implemented a multiscale mathematical model that links the injection of 5FU to its efficacy on tumor growth by integrating its pharmacokinetics and mechanism of intracellular action. Population simulations of this model, using parameters from the literature, allowed us (i) to reproduce clinical results showing the predictive power of TS enzyme level and (ii) to identify two potential predictors of response to 5FU at the level of a population of virtual patients, in addition to TS level. We also analyzed, using mixed effects models, (i) the in vivo growth of intrahepatic VX2 tumor without treatment, serving as an animal model of liver metastasis, and (ii) the distribution of 5FU in the animal’s organism. This statistical modelization enabled us to identify the models describing experimental data, to estimate the parameters of these models and their variability, and generate a better knowledge of VX2 tumor growth and animal 5FU pharmacokinetics. In this thesis, we illustrated how the integration of drug metabolism and its mechanism of action in a global model and the simulation of this model at the scale of a virtual population, form a promising approach to optimize the development of innovative therapeutic hypotheses in collaboration with experimentalists.

The thesis entitled “The Role of Liposomal Hybrids and Gold Nanoparticles in the Efficacious Transport of Nucleic Acids and Small Molecular Drugs for Cancer Nanomedicine” elucidates the preparation of various liposomal formulations of cationic monomeric and gemini lipids where hydrophobic domains were consisted of tocopherol, cholesterol and pseudoglyceryl backbone for the cellular transport of nucleic acids. The thesis continues while elucidating the role of various pH sensitive molecules and gold nanoparticles in liposomes to improve the delivery efficacy levels. This thesis also elucidates the role of gold nanoparticles stabilized with natural pH sensitive molecules for efficacious drug delivery applications. Additionally, the role of such pH sensitive gold nanoparticles in association with liposomes for the co-delivery of drug and gene has been discussed. The work has been divided into six chapters. Chapter 1A: Dimeric Lipids Derived from α-Tocopherol as Efficient Gene Transfection Agents. Mechanistic Insights into Lipoplex Internalization and Therapeutic Induction of Apoptotic Activity In this chapter, we present cationic dimeric (gemini) lipids for significant plasmid DNA (pDNA) delivery to different cell lines without any marked toxicity in the presence of serum. The six gemini lipids possess α-tocopherol as their hydrophobic backbone and differ from each other in terms of their spacer chain lengths. Each of these gemini lipids mixed with a helper lipid 1, 2-dioleoyl phosphatidyl ethanolamine (DOPE), was capable of forming stable aqueous suspensions. These co-liposomal systems were examined for their potential to transfect pEGFP-C3 plasmid DNA in to nine cell lines of different origins. The transfection efficacies noticed in terms of EGFP expression levels using flow cytometry were well corroborated using independent fluorescence microscopy studies. Significant EGFP expression levels were reported using the gemini co-liposomes which counted significantly better than one well known commercial formulation lipofectamine 2000 (L2K). Transfection efficacies were also analyzed in terms of the degree of intracellular delivery of labeled plasmid DNA (pDNA) using confocal microscopy which revealed an efficient internalization in the presence of serum. The cell viability assays performed using optimized formulations demonstrated no significant toxicity towards any of the cell lines used in the study. We also had a look at the lipoplex internalization pathway to profile the uptake characteristics. A caveolae/lipid raft route was attributed to their excellent gene transfection capabilities. The study was further advanced by using a therapeutic p53-EGFP-C3 plasmid and the apoptotic activity was observed using FACS and growth inhibition assay. Figure 1. The co-liposomes of tocopheryl gemini lipids and DOPE for efficient delivery of p53-EGFP-C3 plasmid DNA that induces significant apoptotic response. Chapter 1B: Efficacious Gene Silencing in Serum and Significant Apoptotic Activity Induction by Survivin Downregulation Mediated by Cationic Gemini Tocopheryl Lipids Non-viral gene delivery offers cationic liposomes as promising instruments for the delivery of double-stranded RNA (ds RNA) molecules for successful sequence-specific gene silencing (RNA interference). The efficient delivery of siRNA (small interfering RNA) to cells while avoiding the unexpected side effects is an important prerequisite for the exploitation of the power of this excellent tool. We discuss in this chapter about six tocopherol based cationic gemini lipids, which induce substantial gene knockdown without any obvious cytotoxicity. All the efficient co-liposomal formulations derived from each of these geminis and a helper lipid, dioleoyl phosphatidyl ethanolamine (DOPE) were well characterized using physical methods such as atomic force microscopy (AFM) and dynamic light scattering (DLS). Zeta potential measurements were conducted to estimate the surface charge of these formulations. Flow cytometric analysis showed that the optimized co-liposomal formulations could transfect anti-GFP siRNA efficiently in three different GFP expressing cell lines, viz. HEK 293T, HeLa and Caco-2 significantly better than a potent commercial standard Lipofectamine 2000 (L2K) both in the absence and presence of serum (FBS). Notably, the knockdown activity of co-liposomes of gemini lipids was not affected even in the presence of serum (10% and 50% FBS) while it dropped down for L2K significantly. Observations under a fluorescence microscope, RT-PCR and western blot analysis substantiated the flow cytometry results. The efficient cellular entry of labeled siRNA in GFP expressing cells as evidenced from confocal microscopy put forward these gemini lipids among the potent lipidic carriers for siRNA. The efficient transfection capabilities were also profiled in a more relevant fashion while performing siRNA transfections against survivin (an anti-apoptotic protein) which induced substantial apoptosis. Furthermore, the survivin downregulation improved the therapeutic efficacy levels of an anticancer drug, doxorubicin significantly. In short, the new tocopherol based gemini lipids appear to be highly promising for achieving siRNA mediated gene knockdown in various cell lines. Figure 2. The co-liposomes of tocopheryl gemini lipids and DOPE for efficient delivery of siRNA against survivin that induces significant apoptotic response. Chapter 2: Efficacious in Vitro EGFP Expression and Silencing in Serum by Cationic Pseudoglyceryl Gemini Lipids To elicit the desirable efficacy levels in cationic liposome mediated nucleic acid therapeutics has been part of extensive scientific efforts. This chapter describes three cationic gemini lipids and application of their co-liposomes with DOPE as potent pDNA (plasmid DNA) and siRNA (small interfering RNA) cytofectins for remarkably advanced efficacy levels in numerous cell lines in the presence of serum. The hydrophobic structural lineament of cationic gemini lipids is made up of pseudoglyceryl backbone linked to the hydrocarbon chains via oligo-oxyethylene units. The stable aqueous co-liposomal suspensions of gemini lipids showed an efficient binding to pDNA or siRNA and their significant intracellular delivery in various cell lines. The transfection capabilities of different co-liposomal formulations were profiled based on EGFP expression (pEGFP-C3 pDNA transfection) and EGFP knockdown (anti-GFP siRNA transfections) in EGFP expressing cell lines. The cellular EGFP expression levels and intracellular delivery of labeled nucleic acids were thoroughly studied using flow cytometry (FACS), fluorescence and confocal microscopy. The MTT based cell viability assay revealed no loss in cell viabilities for all of the transfection optimized lipoplexes of siRNA or pDNA. The transfection profile of gemini co-liposomes was noted to be significantly much better than a commercial lipofection reagent, Lipofectamine 2000 used for pDNA and siRNA applications in each of the cell lines studied. The co-liposomes and their transfection optimized lipoplexes were physiochemically characterized extensively by means of zeta potential, dynamic light scattering (DLS) and atomic force microscopy (AFM). In brief, these new gemini co-liposomal formulations seem to offer a great opportunity for successful nucleic acid (DNA and siRNA) delivery in a practical scenario. Figure 3. Efficacious EGFP expression (pDNA transfection) and EGFP silencing (anti GFP siRNA transfection) mediated by co-liposomes of pseudoglyceryl gemini lipids and DOPE. Chapter 3: Efficient Elicitation of Liposomal Nucleic acid delivery through the Eminence of Gold Nanoparticles Stabilized with pH Responsive Short Tripeptide Derived from Tyrosine Kinase NGF Receptors The prerequisite in the area of gene therapy today is to serve transfection efficient formulations nullifying the enduring key issues. To this end, we discuss in this chapter, the role of hybrid liposomal formulations derived from structurally distinct cationic lipids, a neutral lipid (DOPE) and pH responsive short tripeptide (KFG, Lys-Phe-Gly) capped gold nanoparticles (PAuNPs). The hybrid liposomes are presented to be efficient enough to transfect pDNA leading to remarkably high gene expression levels in various cell lines of different origins in the presence of serum (FBS). Hybrid liposomes could deliver pDNA more effectively than the native liposomes and commercial standard lipofectamine 2000 (L2K) across the entire range of N/P ratios studied under the influence of intracellular pH response and gold nanoparticles prominence. The gene transfection capabilities are profiled based on transfections performed using two different plasmids (pGL3, luciferase activity and p-EGFP-C3, green fluorescent protein expression). pDNA cellular internalization and subsequent gene expression levels are studied using flow cytometry, fluorescence microscopy and confocal microscopic studies. The extensive physiochemical characterization of hybrid liposomal formulation and their complexes with pDNA in comparison with respective native liposomes was performed using AFM, TEM, Zeta, DLS, gel retardation assay, U.V. and fluorescence emission measurements. The hybrid liposomes are shown to possess significantly higher fusion activity at lowered pH of intracellular compartments. These hybrid liposomes are fairly biocompatible across the concentration range used in transfection experiments. Precisely, introduction of these pH responsive tripeptide capped gold nanoparticles in to liposomal formulations straightforwardly must be more advantageous for a practical application in biomedical scenario to achieve therapeutic levels. Figure 4. The hybrid of liposomes and tri-peptide capped gold nanoparticles for significantly improved gene expression levels. Chapter 4: RNA Aptamer Decorated pH Sensitive Liposomes for Active Transport of Nucleic Acids in Specific Cancer Cells This chapter describes the target specific transport of pH sensitive liposomes loaded with a RNA aptamer for promising nucleic acid therapeutics. The pH sensitive liposomes are constructed from a cationic cholesteryl gemini lipid (CGL), neutral helper lipid (DOPE) and gemini analog of a pH sensitive lipid, palmitoyl homocysteine (GPHC). The liposomes are shown to be significantly fusogenic that deliver the cargoes upon lowerin the pH (6.0). The fusogenic behaviour of the liposomes was thoroughly studied by means of dynamic light scattering (DLS), zeta potential, lipid mixing, calcein dequenching and atomic force microscopy (AFM). The facile integration of cholesterol conjugated RNA aptamer in liposomes derived from cholesteryl gemini lipids was exploited for their delivery to specific cancer cells. The RNA aptamer specifically binds to epithelial cell adhesion molecule (EpCAM) with high affinity which is a cell surface marker in various solid cancers such as colorectal and breast carcinoma. These aptamer decorated pH sensitive liposomes could efficiently enter the EpCAM expressing COLO-205, Caco-2, MCF-7 and MDA-MB-231 cell lines while no such noticeable liposome transport was observed in EpCAM negative HEK 293T cells as evidenced by flow cytometry and confocal microscopy. Additionally, the liposomes are shown to be actively transported inside the cells, i.e., receptor mediated endocytosis. These liposomes could complex the nucleic acids (pDNA) in an efficient manner. The MTT based cell viability assay accounted no noticeable loss in cell viabilities for liposome treatments. Concisely, we have formulated RNA aptamer loaded pH sensitive liposomes that would certainly be promising tool in target based cancer nanomedicine. Figure 5. (A) Cellular internalization of DY-647 labeled aptamer loaded pH sensitive liposomes. (B) The liposomes were actively internalized through receptor mediated endocytosis. Each panel (A and B) represents (from left to right) bright field image, aptamer fluorescence, DAPI stained nuclei and merge of previous three impressions. Chapter 5: Natural Tri-peptide Capped Gold Nanoparticles for Efficacious Doxorubicin Delivery in Vitro and in Vivo Nanotechnology has gained ever increasing interest for the successful implementation of chemotherapy based treatment of cancer. This chapter describes the role of gold nanoparticles (AuNPs) capped with a natural pH responsive short tri-peptide (Lys-Phe–Gly or KFG) for significant intracellular delivery of an anti-cancer drug, doxorubicin (DOX). A significantly increased apoptotic response was noted for DOX treatments mediated by KFG-AuNPs in comparison with drug alone treatments in various cell lines (BT-474, HeLa, HEK 293T and U251) in vitro. Furthermore, KFG-AuNPs mediated DOX treatment significantly decreased cell proliferation and tumor growth in BT-474 cell xenograft model in nude mice. In addition, KFG-AuNPs showed efficacious drug delivery in DOX-resistant HeLa cells (HeLa-DOXR) in comparison with drug alone treatments. Figure 6. Representative images of excised tumors after doxorubicin treatment mediated by pH responsive tri-peptide capped gold nanoparticles (DOX-KFG-AuNPs) (C) in comparison with doxorubicin alone treatments (B) and untreated tumors (A). Extensive cell death as observed under Hematoxylin/eosin (H&E) (D) and TUNEL (E) staining of DOX-KFG-AuNPs treated tumor sections. Chapter 6: Significant Apoptotic Activity Induction by Efficacious Co-delivery of p53 Gene and Doxorubicin Mediated by the Combination of Co-liposomes of Cationic Gemini lipid and pH Responsive Tri-peptide Combining chemotherapy with gene therapy has appeared as an efficient tool to treat complex biological disorder like cancer. Herein, we show efficient co-delivery of DNA and an anti-cancer drug, doxorubicin (DOX) by means of gemini cationic liposome (GCL) based lipoplex nanoaggregates that are coated with DOX encapsulated pH responsive tripeptide nanovesicles. The lipoplex, tripeptide vesicles and their association was thoroughly studied using dynamic light scattering (DLS), zeta potential, atomic force microscopy (AFM). Flow cytometry, fluorescence and confocal microscopic analysis revealed that the GCL-tripeptide association could significantly co-deliver the p53 expression plasmid (p53-EGFP-C3) and DOX in HeLa and HEK 293T cells in the presence of serum. A synergistic increase in gene expression level and DOX internalization was observed in co-delivery which was even substantially higher than individual lipoplex transfection and DOX treatment. The apoptosis induced due to p53 expression and DOX was profiled with the help of annexin-V positivity analysis under flow cytometry and nuclear damage analysis by DAPI nuclei counterstaining under confocal microscopy which noted to be significantly higher in cells during co-delivery. The MTT based cell viability assay revealed a significantly increased loss in cell viability counts for co-delivery treatments. Such a system delivering synergistically increased significant efficacy levels in combinatorial drug and nucleic acid therapeutics would be certainly advantageous for practical biomedical applications. Figure 7. The co-delivery of pDNA and drug (doxorubicin) mediated by GCL-tripeptide association as observed under (A) confocal microscopy (pDNA; green and doxorubicin; red) and (B) flow cytometry.

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The past few years have witnessed significant work being directed towards drug delivery systems with layer-by layer (LbL) technique prominently featured as one of the most sought after approach. However, majority of the studies were focused on the fabrication of microcapsules which produced numerous drawbacks resulting in reduced applicability. This has spurred research into nanocapsules which has proved to overcome most of the drawbacks that plagued microcapsules by being able to evade the reticulo-endothelial system, exhibit enhanced permeability and retention in tumours etc. The capsules fabricated by the LbL technique requires a suitable combination of cationic and anionic polyelectrolytes which ensures that it is able to effectively protect the cargo it encapsulates as well as enhance its bio-applications. With numerous advantages such as biocompatibility and biodegradability to name a few, chitosan has proved to be an ideal cationic polyelectrolyte. Thus, this thesis focuses on the various therapeutic applications of LbL fabricated chitosan based nanocapsules. The first work focuses on the targeted delivery of the somatostatin analogue, Octreotide conjugated nanocapsules to over expressed somatostatin receptors. These LbL fabricated nanocapsules composed of chitosan and dextran sulfate (CD) encapsulate the anti cancer drug, doxorubicin and are found to attain site specificity as well as enhanced anti-proliferative activity. The results indicated that the nanocapsules were biocompatible and when conjugated with octreotide was found to have an enhanced internalization into SSTR expressing cells, thereby making it a viable strategy for the treatment of tumors that has an over expression of somatostatin receptors such as pancreatic carcinoma, breast carcinoma etc. The objective of the second work was to develop an efficient drug delivery system such as CD nanocapsules for encapsulation of Ciprofloxacin in order to combat infection by Salmonella, an intracellular and intra-phagosomal pathogen. In vitro and in vivo experiments showed that this delivery system can be used effectively to clear Salmonella infection. The increased retention of ciprofloxacin in tissues delivered by CD nanocapsules as compared to the conventional delivery proved that the same therapeutic effect was obtained with reduced dosage and frequency of Ciprofloxacin administration. The third work deals with the probiotic, Saccharomyces boulardii which is found to be effective against several gastrointestinal diseases but had limited clinical application due to its sensitivity to acidic environment. However, encapsulation of S. boulardii with chitosan and dextran sulfate ensured enhanced viability and selective permeability on exposure to acidic and alkaline conditions experienced during gastro intestinal transit. The final work involves the fabrication of novel pH responsive nanocapsules composed of chitosan-heparin which facilitate the intracellular delivery of a model anti-cancer drug, doxorubicin.