Title of Invention

A BIOACTIVE CATIONIC AMPHIPHILE FOR INTRACELLULAR DELIVERY OF THERAPEUTIC MOLECULES AND A PROCESS FOR THE PREPARATION THEREOF

Abstract A BIOACT1VE CATIONIC AMPH1PHILE The present invention provides novel cationic amphiphiles capable of facilitating transport of biologically active molecules into cells wherein the said amphiphiles contain cyclic head group having polar functional groups and pharmaceutical composition useful for delivering biologically active therapeutic molecules into body cells.
Full Text CATIONIC AMPHIPHILES FOR INTRACELLULAR DELIVERY OF
THERAPEUTIC MOLECULES ITS COMPOSITION, PROCESS AND USE
THEREOF
TECHNICAL FIELD
The present invention relates to novel cationic amphiphiles containing cyclic head
group. The present invention also relates to a pharmaceutical composition comprising
said cationic amphiphiles, useful for the delivery of biologically active therapeutic
molecules into body cells/tissues of mammals.
BACKGROUND ART
Although many defective genes associated with numerous genetic diseases have been
identified and characterized, because of the selective permeability of biological cell
membranes, delivering required amounts of therapeutically important genes into the
target body cells is often a daunting^hailenge.
Thus, success of gene therapy approach in treating genetic diseases depends, in a
major way, on the development of efficient and safe gene delivery reagents that will
facilitate the intracellular delivery of therapeutic genes into the particular body cells
of a patient. Accordingly, development of safe and efficient gene delivery reagents
and methods that can facilitate entry of functional genes into body cells are of great
medical importance.
Amphiphilic molecules containing both polar and non-polar regions in their molecular
architecture have been used in delivering therapeutically important molecules into
cells. This makes sense given the existence of both polar and non-polar segments in
biological cell membranes. Cationic amphiphiles are the particularly important class
of amphiphilic compounds used most extensively for enhancing intracellular delivery
of many biologically active therapeutic compounds. Broadly speaking, at'
physiological pH the polar segment of cationic amphiphile interacts with the
therapeutically important molecules including polyanionic macromolecular DNA,
RNA, proteins etc. while the non-polar region of the cationic amphiphiles facilitate
the passage of the therapeutic compounds through the non-polar part of the cell
membranes.
The following references are examples of cationic amphiphiles that are known in the
art to be useful for enhancing the intracellular delivery of therapeutically important
molecules. In addition to the molecular structures, these prior arts contain useful
information and discussion on the properties of the cationic amphiphiles those are
believed to be responsible for their carrier properties.
Feigner et al., Proc.Natl.Acad.Sci. U.S.A., 84, 7413-7417 (1987), reported the first use
of a highly efficient cationic lipid N-[l-(2,3-dioleyloxy)propyl]-N,N,N-trimethyl
ammonium chloride(DOTMA) as the DNA transfection vector.
U.S. Pat.Nos. 4,897,355 and 4,946,787 (1990) reported the synthesis and use of N-
[.omega..(.omega.-l)-dialkyloxy]-and N-[..omega..(.omega.-l)-dialkenyloxy]-alk-lyl-
N,N,N-tetrasubstituted ammonium amphiphiles and their pharmaceutical
formulation as efficient transfection vectors.
Leventis, R.and Silvius, J.R Biochim. Biophys. Acta. 1023, 124-132, (1990) reported
the interactions of mammalian cells with lipid dispersions containing novel
metabolizable cationic amphiphiles.
U.S. Pat.Nos.5,264,618 (1993) reported the synthesis and use of additional series of
highly efficient cationic lipids for intracellular delivery of biologically active_
molecules.
Feigner et al. J.Biol.Chem. 269, 2550-2561 (1994) reported enhanced gene delivery
and mechanistic studies with a novel series of cationic lipid formulations.
U.S.Pat.No. 5,283,185 (1994) reported the synthesis and use of 3p[N-(N',N'-
dimethylaminoethane)carbamoyl]cholesterol, termed as "DC-Chol"for delivery of a
plasmid carrying a gene for chloramphenicol acetyl transferase into cultured
mammalian cells.
U.S. Pat. No. 5,283,185 (1994) reported the use of N-[2-[[2,5-bis[(3-
aminopropyl)amino]-l-Oxopentyl]aminoethyl]-N,N-dimethyl-2,3-bis-(9-
octadecenyloxy)-l-Propanaminium tetra(trifluoroacetate), one of the most widely
used cationic lipids in gene delivery. The pharmaceutical formulation containing this
cationic lipid is sold commercially under the trade name "Lipofectamine".
Solodin et al. Biochemistry 34,13537-13544, (1995) reported a novel series of
amphilic imidazolinium compounds for in vitro and in vivo gene delivery.
Wheeler et al. Proc. Natl. AcadSci. U.S.A 93, 11454-11459, (1996) reported a novel
cationic lipid that greatly enhances plasmid DNA delivery and expression in mouse
lung.
U.S.Pat No. 5,527,928 (1996) reported the synthesis and the use of N,N,N,Ntetramethyl-
N,N-bis (hydroxy ethyl)-2,3-di(oleolyoxy)-l,4-butanediammonim iodide
i.e pharmaceutical formulation as transfection vector.
U.S.Pat.No. 5.698,721 (1997) reported the synthesis and use of alkyl O-phosphate
esters cf diacylphosphate compounds such as phosphatidylcholine or
posphatidylethanolamine for intracellular delivery of macromolecules.
U.S.Pat.Nos. 5,661,018; 5,686,620and 5,688,958 (1997) disclosed a novel class of
cationic phospholipids containing phosphotriester derivatives of
phosphoglycerides and sphingolipids efficient in the lipofection of nucleic acids.
U.S.Pat.No. 5,614,503 (1997) reported the synthesis and use of an amphiphatic
transporter for delivery of nucleic acid into cells, comprising an essentially nontoxic,
biodegradable cationic compound having a cationic polyamine head group capable of
binding a nucleic acid and a cholesterol lipid tail capable of associating with a cellular
membrane.
U.S.Pat.No. 5,705,693 (1998) disclosed the method of preparation and use of new
cationic lipids and intermediates in their synthesis that are useful for transfecting
nucleic acids or peptides into prokaryotic or eukaryotic cells. These lipids comprise
one or two substituted arginine, lysine or ornithine residues, or derivatives thereof,
linked to a lipophilic moiety.
U.S.Pat. No.5, 719,131 (1998) has reported the synthesis of a series of novel cationic
amphiphiles that facilitate transport of genes into cells. The amphiphiles contain
lipophilic groups derived from steroids, from mono or dialkylamines, alkylamines or
polyalkylamines.
US. Patent No. 5,527,928, (1996) reported on the synthesis and transfection biology
of a novel cationic lipid namely, N, N, N', N'-tetramethyl-N, N'-bis (2-
hydroxyethyl)-2,3-di(oleoyloxy)-l,4-butaneammonium iodide.
OTHER PUBLICATIONS
Behr, J.P., Demeneix, B., Loeffler, J.P. and Perex-Mutul, J. Proc. Natl. Acad. Sci.
USA,1989,86, 124-132.
Levantis, R., and Silvius, J.R. Biochim. Biophys. Acta., 1990,1023, 124-132.
Gao, X. and Huang, L. Biochim. Biophys. Res. Commun., 1991, 779, 280-285.
Akao, T., Nakayama, T., Takeshia, K. and Ito, A., Biochem. Mol. Biol. Int., 1994, 34,
915-920.
Feigner, J. H.; Kumar, R.; Sridhar, C. N.; Wheeler, C. J.; Tsai, Y-J.; Border, R.;
Ramsey, P.; Martin, M; Feigner, P. L. J. Biol. Chem., 1994, 269, 2550-2561.
Wheeler, C.J.; Feigner, P.L.; Tsai, Y.J.; Marshall, J.; Sukhu, L.; Doh, S.G.; Hartikka,
J.; Nietupski, J.; Manthorpe. M.; Nichols, M. Proc. Natl. Acad. Sci. USA. 1996, 93,
11454-11459.
Bennett, M. J.; Aberle, A. M.; Balasubramaniam, R. P.; Malone, J. G.; Malone, R.
W.; Nantz, M. H. J. Med Chem. 1997, 40, 4069-4078.
Blessing, T.; Remy, J.-S.; Behr, J.-P.; J. Am. Chem. Soc., 1998,120, 8519-8520.
Wang, J.; Guo, X.; Xu, Y.; Barren, L.; Szoka, F.C., J. Med Chem, 1998, 41, 2207-
2215
Lim, Y.; Choi, Y. H.; Park, J. J. Am. Chem. Soc., 1999,121, 5633-5639.
Lim, Y.; Kim, C.; Kim, K.; Kim, S. W.; Park, J. J. Am. Chem. Soc., 2000,122, 6524-
6525.
Zhu, J.; Munn, R. J.; Naritz, M. H. J. Am. Chem. Soc., 2000, 722, 2645-2646.
Vandenburg, Y. R.; Smith, B. D.; Perez-Payan, N.; Davis, A. P.; J. Am. Chem. Soc.,
2000, 722, 3252-3253.
Lynn. D. M.; Langer, R.; J. Am. Chem. Soc., 2000, 722, 10761-10768.
Ferrari, M. E.; Rusalov, D.; Enas, J.; Wheeler, C. J.; Nuc. Acid Res. 2001, 29, 1539-
1548.
Banerjee, R.; Das, P. K.; Srilakshmi, G.V.; Chaudhuri, A.; Rao, N. M. J. Med
Chem. 1999, 42, 4292-4299.
Banerjee, R.; Mahidhar, Y. V.; Chaudhuri, A.; Gopal, V.; Rao, N. M.
J. Med Chem. 2001, 44,4176-4185.
Singh, S. R.; Mukherjee, K.; Banerjee, R.; Chaudhuri, A.; Hait, S. K.; Moulik, S. P.;
Ramadas, Y.; Vijayalakshmi, A.; Rao, N. M. Chem. Eur. J. (in press).
Floch, V.; Bolc'h, G. Le.; Gable-Guillaume, C.; Bris, N. Le.; Yaouanc, J-J.; Abbayes,
H. Des.; Fe'rec, C.; Cle'ment, J-C. Eur. J. Med. Chem., 1998, 33, 923-934.
Solodin, I.; Brown, C.; Bruno, M.; Chow, C.; Jang, E-H.; Debs, R.; Heath, T.
Biochemistry, 1995, 34, 13537-13544.
OBJECTS OF THE INVENTION
The main object of the invention is to provide novel cationic amphiphilic compounds
containing polar cyclic head group.
Another object of the invention is to provide novel cationic amphiphilic compounds,
which are useful for delivering therapeutically effective amounts of biologically
active molecules into cells/tissues of mammals.
Yet another object of the invention is to provide cas f ic amphiphilic compounds in
which a hydrophobic group is directly linked to the -j .itively charged Nitrogen atom,
which is itself in the cyclic ring containing two hydr ^yl groups.
Still another object of the invention is to pr -ide novel cationic amphiphilic
compounds without any glycerol backbone in the structure.
Another object of the invention is to pro ide novel therapeutic formulation
comprising one or more of the cationic amphif die compounds of the invention.
It is a further object of the invention to prov; e therapeutic formulation useful in gene
therapy and delivery of biologically active olecules into cells/tissues of mammals.
SUMMARY OF THE INVENTION
The present invention relates to novel itionic amphiphilic compounds that facilitate
the intracellular delivery of biologic? ,y active (therapeutic) molecules. The present
invention also relates to pharmr jutical compositions comprising such cationic
amphiphiles those are useful for .divering biologically active therapeutic molecules
into body cells. The novel c .ic-nic lipids of the present invention are particularly
uc al to combat genetic dis RETAILED DESCRIPT >N OF THE INVENTION
The present invention jrovides for a bioactive cationic amphiphile represented by a
general formula (I).
(Figure Removed)
wherein;
R1 and R2 independently represent hydrogen atom or lipophilic moiety
excluding the possible definition for R1 and R2 being simultaneously as
hydrogen atom;
R3 and R4 independently represent hydrogen or a polar group;
n= 1,2 or 3;
X = an inorganic or organic anion.
The present invention also provides a bioactive cationic amphiphile as represented by
general formula (II)
(Figure Removed)
Wherein RI, Ra, R3 and R4 independently or in combination represented as described
below:
n=l
R, = R2 = CH3-(CH2)10CH2-, CH3-(CH2)12CH2-, CH3-(CH2)14 CH2-, CH3-(CH2)16CH2-
aiid/'or CH3-(CH2)7-CH-CK(CH2)7CH2.
R3 = R4 = hydroxyl group.
An embodiment of the present invention, wherein X is selected from halogen atom,
tosyl group and acetate group.
Yet another embodiment of the present invention, wherein R1 is hydrogen and R2 is
Cg.22 saturated alkyl group or an unsaturated alkyl group having one to three
unsaturation.
Still another embodiment of the present invention, wherein R1 is Cg.22 alkyl group
saturated or unsaturated alkyl group having one to three unsaturation and R2 is
hydrogen atom or C8-22 saturated or unsaturated alkyl group having one to three
double unsaturation.
Further embodiment of the present invention, wherein R3 and R4 are independently
represented by any combination of groups selected from hydrogen, hydroxy, hydroxy
alkyl, and amino or primary amine.
Still another embodiment of the present inver ', vherein hydroxy alkyl and primary
amine consists of 1-5-carbon atoms.
Yet another embodiment of the present invention, wherein R1 independently
represents a hydrogen atom and R2 is represented by Cg.22 carbon atoms selected from
saturated alkyl or unsaturated alkyl chain having one to three double bonds.
Still another embodiment of the present invention, wherein R1 represents Cg.22 carbon
atoms selected from saturated alkyl or unsaturated alkyl chain having one to three
double bonds and R2 independently represents a hydrogen atom.
Yet another embodiment of the present invention, wherein both R1 and R2 are
represented by Cg.22 carbon atoms selected from saturated alkyl or unsaturated alkyl
chain having one to three double bonds.
Still another embodiment of the present invention, wherein said compound having a
hydrophobic group is directly linked to the positively charged Nitrogen atom, which
by itself is a part of cyclic ring containing polar substituted groups.
The present invention also provides for a pharmaceutical composition for intracellular
delivery of biologically active molecules, said composition comprising:
at least a cationic amphiphile;
a bioactive molecule;
a colipid; and
optionally an additive.
An embodiment of the present invention, a pharmaceutical composition wherein the
bioactive cationic amphiphile used to facilitate the intracellular delivery of bioactive
molecules having the following structural formula:
(Figure Removed)
wherein;
R1 and R2 independently represent hydrogen atom or lipophilic moiety
excluding the possible definition for R1 and R2 being simultaneously a
hydrogen atom;
R3 and R4 independently represent hydrogen or a polar group;
n = 1, 2 or 3;
X = an inorganic or organic anion.
Yet another embodiment of the present invention, a pharmaceutical composition
wherein the bioactive molecule is selected from the group consisting of ribosomal
RNA, antisense polynucleotide of DNA or RNA, polynucleotide of genomic DNA,
cDNA or mRNA that encodes for therapeutically important protein, nucleic acid, an
i
oligonucleotide and a peptide.
Still another embodiment of the present invention, a pharmaceutical composition
wherein the nucleic acid is circular, lineal plasmid or RNA.
Further embodiment of the present invention, a pharmaceutical composition wherein
the colipid is selected from the group consisting of cholesterol,
phosphatidylethanolamine, phosphatidylglycerol.
Still another embodiment of the present invention, a pharmaceutical composition
according to claim 10 wherein the preferred range of cationic amphiphile and colipid is in
the ratio of 1:0-1:2.5.
Yet another embodiment of the present invention, a pharmaceutical composition
wherein said composition administered comprises an effective amount of DNA in the
range of 0.1-0.5 ug with regard to 50.000 cells of an in vitro system.
Still another embodiment of the present invention, a pharmaceutical composition
wherein said composition can be administered intravenously, intramuscularly and
intraperitonially.
Yet another embodiment of the present invention, a pharmaceutical composition
wherein said additives are selected from physiologically acceptable additives.
Further embodiment of the present invention, a pharmaceutical composition wherein said
additives are used to stabilize the formulation and for the effective delivery of bio active
molecule.
Still another embodiment of the present invention, a pharmaceutical composition
wherein said composition can be formulated with lipophilic therapeutic anti cancer
agents selected from doxorubicin, paclitaxel, docetaxel and 5-fluorouracil
Yet another embodiment of the present invention, a pharmaceutical composition
wherein said composition is formulated with viral agents selected from Acyclovir.
Still another embodiment of the present invention, a pharmaceutical composition
wherein said composition is formulated with antibiotics selected from amphotericin
B.
Further embodiment of the present invention, a pharmaceutical composition wherein
said composition is formulated with an anti-influenza agent to deliver to the lung, the
primary site of the infection.
The present invention also provides a process for the preparation of bioactive cationic
amphiphiles of formulae (I-II) said process comprising the steps of:
(a) coupling an appropriate saturated or unsaturated lipophilic aliphatic bromide
with saturated or unsaturated lipophilic aliphatic alkyl amine in polar aprotic
solvents in presence of base to obtain the corresponding aliphatic
hydrophobic secondary amine;
(b) protecting both the terminal primary alcohol groups of an aliphatic
alcohols containing additional polar functionalities with suitable protecting
groups in polar aprotic solvent;
(c) reacting the secondary amine obtained in step (a) with the primary
hydroxyl protected aliphatic polar intermediate obtained in step (b) in
polar aprotic solvents in presence of an organic base to obtain quaternized
amphiphile compound;
(d) passing the quaternized amphiphilic compound obtained in step (c)
through anion-exchange column chromatography and eluting with a
mixture of polar organic solvent to obtain the required cationic
amphiphile.
An embodiment of the present invention, a process wherein the aliphatic saturated
alkyl bromide is selected from the group consisting of 10-30 carbon atoms.
Yet another embodiment of the present invention, a process wherein the aliphatic
saturated alkyl amine is selected from the group consisting of 10-30 carbon atoms.
Further embodiment of the present invention, a process wherein the substituted
primary hydroxyl group as claimed in step (c) is selected from the group consisting of
hydroxyl, hydroxy alkyl, amino or. a primary amino and most preferably hydroxyl or
amino.
Further embodiment of the present invention, a process wherein the amino group is
protected with t-boc, f-moc or any other suitable protective agents.
Still another embodiment of the present invention, a process wherein the aliphatic
unsaturated alkyl amine used is selected from the group consisting of 10-30 carbon
atoms.
Yet another embodiment of the present invention, a process wherein the polar aprotic
solvents in which the reaction is carried out is selected from the group comprising
dimethyl formamide, dimethylsulphoxide, pyridine, triethyl amine.
Further embodiment of the present invention, a process wherein the reaction is carried
out in the presence of weak base selected from inorganic alkali metal carbonates.
Yet another embodiment of the present invention, a process wherein the primary
alcohol protection group is selected from tosyl chloride, mesyl chloride, and the like.
Stiil another embodiment of the present invention, a process wherein the polar aprotic
solvent used in step (a) is selected from dimethyl sulphoxide, N,N-dimethyl
formamide, ethyl acetate, tetrahydrofuran and the like.
Yet another embodiment of the present invention, a process wherein the reaction of
step (a) is carried out at a temperature between 50° C to 100° C.
Still another embodiment of the present invention, a process wherein the protection of
terminal primary hydroxyl groups of step (b) is carried out at a temperature between -
10°Cto50°C.
Further embodiment of the present invention, a process wherein primary alcohol is
selected from erythrytol or its homologues.
Yet another embodiment of the present invention, a process wherein the polar aprotic
solvent used in step (c) is selected from dimethyl sulphoxide, N,N-dimethyl
formamide, ethyl acetate, tetrahydrofuran.
Further embodiment of the present invention a process wherein the organic base used
in step (c) is selected from triethyl amine, pyridine, piperidine.
Yet another embodiment of the present inv -.a process wherein the reaction of
step (c) is carried out at a temperature betwec;. i«j'C to 100°C.
Still another embodiment of the present invention, a process wherein the anionexchange
resin used in step (d) is selected from resin having chloride or bromide ion
available for exchange.
Yet another embodiment of the present invention, a process wherein the organic
solvent used as ingredients of the polar eluent in step (d) is selected from methanol,
ethanol, chloroform, dichloro methane, ethyl acetate.
The present invention further provides for a use for intracellular delivery of
biologically active molecules said use comprising administering to a subject at least
one biologically active compound represented by the following structural formula:
(Figure Removed)
wherein;
R1 and R2 independently represent hydrogen atom or lipophilic moiety
excluding the definition of R1 and R2 being simultaneously represented as
hydrogen atom;
R3 and R4 independently represent hydrogen or a polar group;
n= 1,2, 3 or 4;
X = an inorganic or organic anion.
An embodiment of the present invention, a use wherein the subject is selected from
humans and other species including murine, feline, bovine, equine and ovine or nonhuman
primate species.
Another embodiment of the present invention, a use wherein said use is used to
CL -.ibat genetic diseases by non-viral gen; therapy.
Still another embodiment of the present invention, a use wherein said composition can
be administered intravenously, intramuscularly and intraperitonially.
Yet another embodiment of the present invention, a use wherein cytotoxicities are
minimal and the cell viability more than 80%.
Yet another embodiment of the present invention, wherein said use is used to
construct cell lines for gene therapy applications in said subjects.
The present invention is also further explained in the form of preferred embodiments.
The distinctive novel structural features common to the cationic amphiphiles
disclosed in the present invention include:
(1) The presence of hydrophobic groups which are directly linked to the positively
charged nitrogen atom;
(2) The positively charged nitrogen atom is part of the cyclic head group; and
(3) Unlike many other, commercially available iglycerol-backbone based cationic
amphiphiles used in delivering genes into cells, the presently disclosed cationic
lipids do not have any glycerol-backbone in their molecular architectures. It is
believed that these unique structural features contribute significantly to the
increased gene delivery efficiencies of the cationic amphiphiles disclosed herein.
According to the practice of the present invention, "cationic" means the positive
charge is either on quaternized nitrogen and/or on a protonated substituent of the
cyclic head group. The cationic characters of the present amphiphiles may contribute
to the enhanced interaction of the amphiphiles with biologically active molecules such
as nucleic acids and/or with cell constituents such as plasma membrane glycoproteins.
Such enhanced interaction between the cationic amphiphiles and therapeutically
active biological macromolecules and/or cell membrane constituents may play a key
role in successfully transporting the therapeutic molecules into the cells.
The invention cationic lipids have a lipophilic domain that facilitates the formation of
lipid complexes or aggregates in aqueous solutions. The lipophilicity of the
hydrophobic domains and the hydrophilicity of the polar head group domains are such
that when the cationic lipids are confronted with aqueous solutions, lipid aggregates
are formed in the presence or absence of a second compound. Exemplary lipophilic
RI and R2 groups include (1) saturated Cg-C22 alkyl groups and (2) unsaturated Cg-C22
alkyl groups containing one to three unsaturation.
In one preferred embodiment of the presently disclosed cationic lipids where n = 1,
both RI and R2 are selected from Cg-C22 saturated alkyl groups, both RS and R4 are
independently represented in any combination of groups selected from hydrogen,
hydroxyl, hydroxy alkyl, amino or primary amine and X" is selected from chloride or
bromide ions.
Syntheses of the cationic lipids
Scheme I outlines the synthetic strategy employed for preparing the cationic lipids of
the present invention containing a five member cyclic head groups (n = 1 in generic
Structure of formula (I). The same synthetic scheme is employed to synthesize
cationic lipids with seven and nine member cyclic head groups (n = 2 and 3
respectively, in generic Structure of formula (I).
(Figure Removed)
the primary hydroxyl groups of the starting alcohol is first converted to their
tosyl derivative by reacting them with p-toluenesulfonyl chloride in presence of
pyridine as a base. The resulting di-tosyl derivative (the intermediate II in Scheme I)
is then subjected to reaction with the appropriate secondary amine in polar aprotic
solvent like N.N-dimethyl formamide to form the cationic amphiphile (III), a tosylate
counterion containing analog of the present cationic lipids. A final treatment of the
intermediate III with chloride ion-exchange resins affords the target cationic
amphiphile (I) of the present invention. As sh in Scheme I, to synthesize cationic
lipids with two hydroxyl functionalities in ..^ cyclic head group, protecting the
secondary hydroxyl group of the starting material is not necessary. However, to
prepare cationic amphiphiles with two amino functionalities in the cyclic head group,
execution of Scheme I requires protection of both the primary amino group of the
starting material and a later deprotection step.
Formulations
The invention also provides novel therapeutic formulation comprising therapeutically
effective amounts of the cationic amphiphilic compounds disclosed herein,
biologically active molecules and co-lipids. One or more additional physiologically
acceptable substances may be included in the pharmaceutical formulation of the
invention to stabilize the formulation for storage or to facilitate successful
intracellular delivery of the biologically active molecules. Co-lipids according to the
practice of the present invention are useful in mixing with one or more cationic
amphiphiles. Cholesterol is an excellent co-lipid for use in combination with the
presently described cationic lipids to facilitate successful intracellular delivery of the
biologically active molecules. A preferred range of molar ratio of cationic amphiphile
to co-lipid is 1:0 to 1:2.5. As such, it is within the art to vary the said range to a
considerably wide extent.
Biologically active molecules that can be administered intracellularly in therapeutic
amounts using the cationic amphiphilic compound of the present invention include
ribosomal RNA, antisense polynucleotide of RNA or DNA, polynucleotide of
genomic DNA, cDNA or mRNA that encodes for a therapeutically important protein.
The cationic amphiphiles of the present invention may be blended such that one or
more of the representatives thereof are used in a combination to facilitate entry of the
said biologically active molecules into cells/tissues.
According to the present invention, the amphiphiles are used either in pure form or in
combination with other lipids or helper lipids such as cholesterol,
phosphatidylethanolamine, phosphatidylglycerol, etc. The said therapeutic
formulation can be stored at 0°C-4°C until complexed with the biologically active
therapeutic molecules. Agents that prevent bacterial growth and increase the shelf life
may be included along with reagents that stabilize the preparation, e.g., low
concentrations of glycerol. It is specifically warned that freezing and thawing cycles
could cause loss in efficiency of the formulation.
The present invention also provides for various formulations that facilitate
intracellular delivery of biologically active molecules.
The present invention also provides for a formulation of cationic amphiphiles and
nucleic acid may be administered intravenously besides other routes such as
intramuscular and intra peritonial. Further, the said formulation of amphiphiles may
be administered to cells at a ratio of 0.1-0.5 microgram of DNA to 50,000 cells in an
in vitro system. The amount of amphiphile could be varied from a lipid to DNA
charge ratio of 0.1 to 10, considering one positive charge for one amphiphile molecule
to one negative charge of a nucleotide base.
The plasmid used is a construct of an Cyto Megalo Virus promoter linked to a
reporter gene p-galactosidase as supplied by Gibco BRL Life Technologies, USA (cat
no.!0586-014)The plasmid could be of any construction and the example given is
merely to demonstrate* the efficiency of the amphiphilic formulation. Similar
examples of plasmid include PGL-2 and PGL-3 of Promega and others.
The invention further provides a process for the preparation of the said formulation
comprising the steps of preparing a dispersion of a cationic amphiphile disclosed in
the present invention; contacting said dispersion with a biologically active molecule
to form a complex between said amphiphiles and said molecules and contacting cells
with said complex thereby facilitating transfer of said biologically active molecules
into the cells.
Cellular Cytotoxicities of the Amphiphiles Disclosed in the Invention
The viabilities of cells in presence of various cationic amphiphiles disclosed herein
were checked according to the standard protocol described in "Animal Cell Culture,
2nd Edition. Ed. I. R. L. Press, Oxford University Press (1977)". The transfection
efficiencies of the cationic lipids were studied in the range of 0-10 nmole and within
this limit, the cell cytotoxicities were observed to be minimal and the cell viabilities
were determined to be more than 80%. The cationic amphiphiles were used with
varying mole ratios of lipid to DNA using cholesterol as the neutral co-lipid.
Applications
The process of the present invention can be exploited for preparing cationic
transfection lipids with polar cyclic head groups. The invention lipids are useful for
delivering polyanions, polypeptides or nucleopolymers into cells. The cationic lipids
disclosed herein can be used to deliver an expression vector into a cell for
manufacturing or therapeutic use. The expression vectors can be used in gene therapy
protocols to deliver a therapeutically useful protein to a cell or for delivering nucleic
acids encoding therapeutically useful protein molecules that can generate an immune
response in a host for vaccine or other immunomodulatory purposes according to the
known uses. The vector-transformed cell can be used to produce commercially useful
cell lines, such as a cell line for producing therapeutic proteins or enzymes (e.g.
erythropoietin), growth factors (e.g. human growth hormone, G-CSF or interleukins)
or other proteins.
The invention lipid-nucleic acid complexes can be used to construct cell lines for gene
therapy applications in subjects such as humans or other species including murine,
feline, bovine, equine, ovine or non-human primate species. The invention lipids can
be used in presence of serum and will thus deliver polyanions into cells in tissue
culture medium containing serum in vitro or in animal in vivo.
The invention lipids complexed with nucleopolymers can be used in antisense
inhibition of gene expression in a cell by delivering an antisense oligonucleotide into
the cell. A cell that is blocked for expression of a specific gene(s) is useful for
manufacturing and therapeutic applications. Exemplary manufacturing uses include
inhibiting protease synthesis in a cell to increase production (i.e., reduce target protein
degradation caused by the protease) of a protein for a therapeutic or diagnostic
application. Exemplary therapeutic applications include inhibiting synthesis of cell
surface antigens (histocompatibility antigens, such as MHC class II genes, and the
like) to reduce rejection and/or to induce immunologic tolerance of the cell after it is
implanted into a subject or when the cell is transfected in vivo.
The invention lipids can be formulated with anionic, zwitterionic and lipophilic
therapeutic agents including anticancer agents such as doxorubicin, a lipophilic
compound, to obtain complexes comprising the invention lipids and a therapeutic
agent(s). The invention lipids can be formulated with known antiviral agents such as
HPMPC (9-(3 -hydroxy-2-phosphonylmethoxy)propyl)cytosine), PMEA(9-(2-
phosphonylmethoxy)ethyl)adenine), PMEG PMEA (9-(2-phosphonylmethoxy) ethyl)
guanine), PMPA (9-(2-phosphonylmethoxy)propyl)adenine), AZT, 3TC, and their
derivatives to obtain lipid complexes with antiviral agents. The invention lipids can
be formulated with polyene antibiotics such as amphotericin B. Such
formulations are useful for delivering the therapeutic agents into the cytoplasm of
cells in vitro or in vivo. Complexes consisting of an invention cationic lipid and an
anti-influenza agent can be used to deliver the antiviral agent to the lung, the primary
site of infection. These complexes can be prepared by any of the techniques now
known or subsequently developed for preparing lipid complexes containing
therapeutic agents.
Brief Description of the Accompanying Drawings
Figure 1 summarizes the in vitro gene delivery efficiencies for the cationic
amphiphiles 1-5 disclosed in the present invention and that of DMRIE, one of the
most widely used commercially available transfection lipids under certain conditions
and
Figure 2 shows some representative lipid:DNA interactions for cationic amphiphiles
1-5 disclosed in the present invention.
Figure 3 provides the in vitro cellular toxicity data of the cationic amphiphiles 1-5
disclosed in the present invention.
EXAMPLES
The following examples are given by way of illustration of the present invention and
therefore should not be construed to limit the scope of the present invention.
Synthetic procedures for representative cationic amphiphiles 1-5 disclosed in the
present invention are described in the following examples 1-5. The structures of
cationic lipids 1-5 are shown below.
THE PROCESS OF PREPARATION OF BIOACTIVE CATIONIC
AMPHIPHILES HAS BEEN CLAIMED AND DISCLOSED IN OUR COPENDING
APPLICATION NO 366NF2003.
(Figure Removed)
Example 1:
Synthesis of N,N-di-n-dodecyl-3,4-dihydroxy pyrrolidinium chloride (amphiphile
1)
Step (a). To 5 g n-dodecyl amine (27 mmol) dissolved in 10 ml DMSO, 6.7 g of ndodecyl
bromide (27 mmol),and 3 7 g of potassium carbonate (27 mmol) were added.
The mixture was kept under stirring for 24 hours at 80° C. The reaction mixture was
taken in chloroform 100 ml and washed with water (2x 150 ml), the chloroform layer
was dried over anhydrous sodium sulfate and filtered. Chloroform was removed from
the filtrate on a rotary evaporator and column chromatographic purification (using 60-
120 mesh size silica) of the residue using 1-2% methanol in chloroform as an eluent
afforded (3.4g, yield 35%) of the desired intermediate secondary amine, namely, N,Ndi-
n-dodecylamine.
Step (b). To erythritol (4 g 33.9 mmol) dissolved in 100 ml dry pyridine, tosyl.
chloride (11.6 g, 61 mmol), a few crystals of DMAP were added. The mixture was
kept under stirring for 1 h at -5°C. Pyridine was removed on a rotary evaporator and
column chromatographic purification (using 60-120 mesh size silica) of the residue
using 25-30% ethyl acetate in pet-ether (v/v) as the eluent provided of crude title
compound 7 g. Pure ditosylate intermediate was obtained (4 g, 27.4% yield) by final
recrystallization of the crude product from chloroform : pet-ether (4:6,25ml).
Step (c). Reacting the purified ditosylate (0.5 g, 1.2 mmol) with 5 equivalent of
secondary amine of step (a) (2.0 g, 5.8 mmol) in triethyl amine 40 ml at 80°C. for 72
hours. Silica gel column chromatographic purification was performed using 60-120
mesh size silica and 10-15% methanol in chloroform as the eluent. Crude title
amphiphile No.l was obtained by subjecting the quaternized salt to repeated treatment
(3 times) with chloride ion-exchange resin, each time using a freshly generated
Amberlyst A-26 chloride ion exchange column and about methanol 75 ml as the
eluent. Finally, pure quaternized title amphiphile salt 1 (0.08 g, 14.5% yield) was
obtained by crystallizing the crude product using chloroform : pet-ether 10 ml 3:7. All
the isolated intermediates gave spectroscopic data in agreement with their assigned
structures.
'H-NMR of amphiphile 1 (200 MHz, CDCl3):8/ppm = 0.9 [6H, t, 2x-CHj]; 1.20-1.45
[36H, m, 18x- CHj]; 1.5-1.8 [4H, m, 2x- CHj,]; 3.4-3.6 [8H, m, -N- CH^]; 4.05-4.2
[2H, m, - CH-OH]; 4.75-4.8 [1H, m, -CH-OH]; 5.5-5.6 [1H, m, -CH-OH].
Example 2:
Procedure for the preparation of NJV-di-n-tetradecyl-3,4-dihydroxy
pyrrolidinium chloride (amphiphile No. 2).
Step (a). To 5 g n-tetradecyl amine (23.4 mmol) dissolved in 10 ml DMSO, 6.4 g of
n-tetradecyl bromide (23.4 mmol),and 3.2 g of potassium carbonate (23.4 mmol) were
added. The mixture was kept under stirring for 24 hours at 80° C. The reaction
mixture was taken in 100 ml chloroform and washed with water (2x 150 ml), the
chloroform layer was dried over anhydrous sodium sulfate and filtered. Chloroform
was removed from the filtrate on a rotary evaporator and column chromatographic
purification (using 60-120 mesh size silica) of the residue using l-2%methanol in
chloroform as the eluent afforded 3.4 g (35% yield) of the desired intermediate
secondary amine, namely, N,N-di-n-tetradecylamine.
Step (b). To 4 g of erythritol (33.9 mmol) dissolved in 100 ml dry pyridine, tosyl
chloride 11.6 g, (61 mmol), a few crystals of DMAP were added. The mixture was
kept under stirring for 1 h at -5°C. Pyridine was removed on a rotary evaporator and
column chromatographic purification (using 60-120 mesh size silica) of the residue
using 25-30% ethyl acetate in pet-ether (v/v) as the eluent provided 7 g of crude title
compound. Pure ditosylate intermediate was obtained (4 g, 27.4% yield) by final
recrystallization of the crude product from 25 ml 4:6 (v/v) chloroform : pet-ether.
Step (c). Reacting the purified ditosylate (0.5 g, 1.2 mmol) with 5 equivalent of
secondary amine (2.4 g, 5.8 mmol) in 40 ml triethyl amine at 80° C. for 72 hours.
Silica gel column chromatographic purification was performed using 60-120 mesh
size silica and 10-15% methanol in chloroform as the eluent. Crude title amphiphile
No. 1 was obtained by subjecting the quaternized salt to repeated (3 times) chloride
ion-exchange column chromatography, each time using a freshly generated Amberlyst
A-26 chloride ion exchange column and about 75 ml of methanol as the eluent.
Finally, pure quaternized title amphiphile salt 2 (0.06 g, 9.7% yield) was obtained by
crystallizing the crude product using 10 ml 3:7 (v/v) chloroform : pet-ether. All the
isolated intermediates gave spectroscopic data in agreement with their assigned
structures.
'H-NMR of amphiphile 2 (200 MHz, CDCl3):5/ppm = 0.9 [6H, t, 2x- CHs]; 1.20-
1.45 [48H, m, 24x- Ofc]; 3.4-3.75 [8H, m, 4xN- CHj]; 4.05-4.20 [2H, m, 2x- CHOH];
4.75-4.80 [1H, m, -CH-OH]; 5.5-5.6 [1H, m, -CH-OH].
Example 3:
Procedure for the preparation of N,N-di-n-hexadecyl-3,4-dihydroxy
pyrrolidinium chloride (amphiphile No. 3).
Step (a). To 5 g n-hexadecyl amine (20.7 mmol) dissolved in 10 ml DMSO, 6.3 g of
n-hexadecyl bromide (20.7 mmol),and 2.9 g of potassium carbonate (20.7 mmol)
were added. The mixture was kept under stirring for 24 hours at 80° C. The reaction
mixture was taken in 100 ml chloroform and washed with water (2x 150 ml), the
chloroform layer was dried over anhydrous sodium sulfate and filtered. Chloroform
was removed from the filtrate on a rotary evaporator and column chromatographic
purification (using 60-120 mesh size silica) of the residue using l-2%methanol in
chloroform as the eluent afforded 3.4 g (35% yield) of the desired intermediate
secondary amine, namely, N,N-di-n-hexadecylamine.
Step (b). To 4 g of erythritol (33.9 mmol) dissolved in 100 ml dry pyridine, tosyl
chloride 11.6 g, (61 mmol), a few crystals of DMAP were added. The mixture was
kept under stirring for 1 h at -5°C. Pyridine was removed on a rotary evaporator and
column chromatographic purification (using 60-120 mesh size silica) of the residue
using 25-30% ethyl acetate in pet-ether (v/v) as the eluent provided 7 g of crude title
compound. Pure ditosylate intermediate was obtained (4 g, 27.4% yield) by final
recrystallization of the crude product from 25 ml 4:6 (v/v) chloroform : pet-ether.
Step (c). Reacting the purified ditosylate (0.5 g, 1.2 mmol) with 5 equivalent of
secondary amine (2.7 g, 5.8 mmol) in 40 ml triethyl amine at 80° C. for 72 hours.
Silica gel column chromatographic purification was performed using 60-120 mesh
size silica and 10-15% methanol in chloroform as the eluent. Crude title amphiphile
No. 1 was obtained by subjecting the quaternized salt to repeated (3 times) chloride
ion-exchange column chromatography, each time using a freshly generated Amberlyst
A-26 chloride ion exchange column and about 75 ml of methanol as the eluent.
Finally, pure quaternized title amphiphile salt 3 (0.13 g, 17.3% yield) was obtained by
crystallizing the crude product using 10 ml 3:7 (v/v) chloroform : pet-ether. All the
isolated intermediates gave spectroscopic data in agreement with their assigned
structures.
'H-NMR of amphiphile 3 (200 MHz, CDCl3):o7ppm =0.90 [6H, t, 2x-CH3]; 1.20-
1.80 [56H, m, 28x- CHJ; 3.40-3.75 [8H, m4x-N- CHs]; 4.05-4.20 [2H, m, 2x- CHOH];
4.75-4.80 [1H, m, -CH- OH]; 5.5-5.6 [1H, m, -CH-OH].
Example 4:
Procedure for the preparation of N,N-di-n-octadecyl-3,4-dihydroxy
pyrrolidinium chloride (amphiphile No. 4).
Step (a). To 5 g n-octadecyl amine (18.5 mmol) dissolved in 10 ml DMSO, 6.2 g of noctadecyl
bromide (18.5 mmol),and 2.6 g of potassium carbonate (18.5 mmol) were
added. The mixture was kept under stirring for 24 hours at 80° C. The reaction
mixture was taken in 100 ml chloroform and washed with water (2x 150 ml), the
chloroform layer was dried over anhydrous sodium sulfate and filtered. Chloroform
was removed from the filtrate on a rotary evaporator and column chromatographic
purification (using 60-120 mesh size silica) of the residue using l-2%methanol in
chloroform as the eluent afforded 3.6 g (37% yield) of the desired intermediate
secondary amine, namely, N,N-di-n-octadecylamine.
Step (b). To 4 g of erythritol (33.9 mmol) dissolved in 100 ml dry pyridine, tosyl
chloride 1 1.6 g, (61 mmol), a few crystals of DMAP were added. The mixture was
kept under stirring for 1 h at -5°C. Pyridine was removed on a rotary evaporator and
column chromatographic purification (using 60-120 mesh size silica) of the residue
using 25-30% ethyl acetate in pet-ether (v/v) as the eluent provided 7 g of crude title
compound. Pure ditosylate intermediate was obtained (4 g, 27.4% yield) by final
recrystailization of the crude product from 25 ml 4:6 (v/v) chloroform : pet-ether.
Step (c). Reacting the purified ditosylate (0.5 g, 1.2 mmol) with 5 equivalent of
secondary amine (3.0 g, 5.8 mmol) in 40 ml triethyl amine at 80° C. for 72 hours.
Silica gel column chromatographic purification was performed using 60-120 mesh
size silica and 10-15% methanol in chloroform as the eluent. Crude title amphiphile
No.4 was obtained by subjecting the quaternized salt to repeated (3 times) chloride
ion-exchange column chromatography, each time using a freshly generated Amberlyst
A-26 chloride ion exchange column and about 75 ml of methanol as the eluent.
Finally, pure quaternized title amphiphile salt 4 (0.08 g, 10.7% yield) was obtained by
crystallizing the crude product using 10 ml 3:7 (v/v) chloroform : pet-ether. All the
isolated intermediates gave spectroscopic data in agreement with their assigned
structures.
'H-NMR of amphiphile 4 (200 MHz, CDCl3):5/ppm = 0.90 [6H, 5, 2x- CHj]; 1.20-
1.45 [64H, m, 32x- CH^]; 3.40-3.75 [8H, m, 4x-N- CH^]; 4.05-4.20 [2H, m, 2x- CHOH];
4.75-4.8 [1H, m, -CH- OH]; 5.5-5.6 [1H, m, -CH-OH].
Example 5:
Procedure for the preparation of N-n-octadecyl-N-oleyl-3,4 dihydroxy
pyrrolidinium chloride (amphiphile No. 5).
Step (a). To 5 g oleyl amine (18.7 mmol) dissolved in 10 ml DMSO, 6.2 g of
octadecyl bromide (18.7 mmol),and 2.6 g of potassium carbonate (18.7 mmol) were
added. The mixture was kept under stirring for 24 hours at 80° C. The reaction
mixture was taken in 100 ml chloroform and washed with water (2x 150 ml), the
chloroform layer was dried over anhydrous sodium sulfate and filtered. Chloroform
was removed from the filtrate on a rotary evaporator and column chromatographic
purification (using 60-120 mesh size silica) of the residue using l-2%methanol in
chloroform as the eluent afforded 2.7 g (27.8% yield) of the desired intermediate
secondary amine, namely, N-n-octadecyl-N-oleyl amine.
Step (b). To 4 g of erythritol (33.9 mmol) dissolved in 100 ml dry pyridine, tosyl
chloride 11.6 g, (61 mmol), a few crystals of DMAP were added. The mixture was
kept under stirring for 1 h at -5°C. Pyridine was removed on a rotary evaporator and
column chromatographic purification (using 60-120 mesh size silica) of the residue
using 25-30% ethyl acetate in pet-ether (v/v) as the eluent provided 7 g of crude title
compound. Pure ditosylate intermediate was obtained (4 g, 27.4% yield) by final
recrystallization of the crude product from 25 ml 4:6 (v/v) chloroform : pet-ether.
Step (c). Reacting the purified ditosylate (0.5 g, 1.2 mmol) with 4 equivalent of
secondary amine (2.4 g, 4.7 mmol) in 40 ml triethyl amine at 80° C. for 72 hours.
Silica gel column chromatographic purification was performed using 60-120 mesh
size silica and 10-15% methanol in chloroform as the eluent. Crude title amphiphile
No.4 was obtained by subjecting the quaternized salt to repeated (3 times) chloride
ion-exchange column chromatography, each time using a freshly generated Amberlyst
A-26 chloride ion exchange column and about 75 ml of methanol as the eluent.
Finally, pure quaternized title amphiphile salt 5 (0.05 g, 7.1% yield) was obtained by
crystallizing the crude product using 10 ml 3:7 (v/v) chloroform : pet-ether. All the
isolated intermediates gave spectroscopic data in agreement with their assigned
structures.
'H-NMR of amphiphile 5 (200 MHz, CDCl3):8/ppm = 0.90 [6H, t, x2- CHj]; 1.20-
1.45 [56H, m, 28x- CH^]; 1.90-2.00 [4H, m, 2x-CH=CH-CH2]; 3.40-3.75 [8H, m, 4x-
N- CHz]; 4.05-4.20 [2H, m, -CH-OH]; 4.75-4.80 [1H, m, -CH-OH]; 5.20-5.40 [1H, m,
-CH-OH].
Example 6:
Cell Transfection. COS-1 cells were seeded at a density of 15,000 cells/well in a 96-
well plate eighteen hours before the transfection. 0.15 fig of plasmid DNA was
complexed with varying amount of lipid (0.05 - 4.3 nmoles) in 13 (4.1 of plain DMEM
medium for 30 min. The charge ratios were varied from 0.1 : 1 to 9 : 1 (+/-) over this
range of the lipid. The complex was diluted to 100 ul with plain DMEM and added to
the wells. After 3 h of incubation, 100 ul of DMEM with 10 % PCS was added to the
cells The medium was changed to 10 % complete medium after 24 h and the reporter
gene activity was estimated after 48 h. The cells were washed twice with PBS and
lysed in 50 nl of lysis buffer (0.25 M Tris.HCl, pH 8.0 and 0.5% NP40). Care was
taken to ensure complete lysis. The P-galactosidase activity per well was estimated
by adding 50 nl of 2X substrate solution (1.33 mg/ml of ONPG, 0.2 M sodium
phosphate, pH 7.15 and 2 mM magnesium chloride) to the lysate in a 96-well plate.
Absorption at 405 nm was converted to P-galactosidase units by using calibration
curve constructed with pure commercial P-galactosidase enzyme.
The values of P-galactosidase units in replicate plates assayed on the same day varied
by less than 30 %. The transfection efficiency values reported were average values
from four replicate transfection plates assayed on the same day. Each transfection
experiment was repeated three times on three different days and the day-to-day
variation in average transfection efficiency values for identically treated replicate
transfection plates was 2-3 fold and was dependent on the cell density and conditions
of the cells. Figure 1 shows representative transfection results obtained with cationic
lipids 1-5. As shown in Figure 1, the in vitro ;ction efficiency of cationic lipid 2
is comparable to or better than that of DMRIE, one of the most extensively used
commercially available cationic transfection lipids used in in vitro gene delivery.
Example 7:
Lipid:DNA Interactions Assay. Intercalation-induced fluorescence increase and
competition with cationic Hpids to bind to DNA has made Ethidium Bromide (EtBr)
an excellent tool to study cationic lipid-DNA interactions. To assess the representative
lipid:DNA interactions for the cationic lipids of the present invention, we have titrated
the EtBr: pCMV p-gal complex with increasing amounts of cationic lipids 1-5.
The extent of Et.Br binding to the DNA was monitored by the changes in the
fluorescence. EtBr fluorescence was monitored in Hitachi 4500 fluorimeter by setting
the excitation wavelength at 518 nm and emission wavelength at 585 nm. To one ml
of TE buffer (pH 8.0), 0.78 nmoles of DNA and 2.5 nmoles of EtBr were added. The
change in fluorescence was monitored after adding small volumes of lipids 1-5 to the
EtBrDNA complex. Arbitrary fluorescence values were recorded after allowing
sufficient time for equilibration. The order of addition of EtBr or lipid to DNA did
not alter the final values indicating that the equilibrium does not depend on the order
of addition and reaches in minutes. Percent fluorescence was calculated considering
the fluorescence value in the absence of lipid as 100.
The data in Figure 2 shows that lipids 1,4 and 5 interact poorly with DNA as seen by
their relatively poor ability to exclude ethidium bromide from DNA. Lipids 2 and 3
interact with DNA equally well up to lipid:DNA ratio of 1.25 or so (Figure 2). The
decrease in EtBr fluorescence at charge ratios of 3:1 was greater than 80 % with all
the lipids 1-5. Taken together the transfection results shown in Figure 1 and the
lipid:DNA interaction profiles shown in Figure 2, it seems that strong lipid:DNA
interactions for the presently described cationic lipids results into better intracellular
gene delivery.
Example 8:
Toxicity Assays. An MTT based viability assay was performed to assess the
cytotoxicity of lipids 1-5 at various lipid:DNA charge ratios with COS-1 cells as
described previously (Banerjee, R. et al. 1999). Except lipid 1, all the other lipids (2-
5) showed least cytotoxicity even at a 9:1 lipid:DNA charge ratio (Figure 3). For
lipias 1, 4 and 5 at a 3:1 charge ratio the toxicity varied from 15-25 % of the ueated
cells. The toxicity of lipid 2 (with shorter alkyl chains) may originate from its
probable detergent-like cell-lysing activity. As shown in Figure 3, the cellular
toxicity profiles of lipids 2-5 of the present invention are better than those of several
commercially available cationic transfection lipids including lipofectin, lipofectAmine
and DMRIE.
ADVANTAGES
1. The novel cationic lipids of the present invention are particularly useful to
combat genetic diseases by non-viral gene therapy.
2. The cationic amphiphiles of the present invention do not have glycerolbackbone
in their molecular structures.
3. The cationic amphiphiles are useful for delivering polyanions, polypeptides
and nucleopolymers into cells.



We claim:
1. A bioactive cationic amphiphile as represented by the general formula I:


(Formula Removed)
wherein R1, R2, R3 and R4 are independently represented as described below: n= 1
R' = R2= CH3-(CH2),OCH2-, CH3-(CH2)|2CH2-, C3--(CH2)I4CH2-CH3--(CH2)16CH2-- or CH3--(CH2)7—CH=CH— (CH2)7--CH2--; R3 = R4 = hydroxyl group; X = an inorganic or organic anion.
2. A bioactive cationic amphiphile as represented by the general formula I:



(Formula Removed)
wherein, n = 1
R and R = C12 to is saturated alky 1 groups,
R3 = R4 = hydroxyl group; and
X = an inorganic or organic anion.


3. A bioactive cationic amphiphile as represented by the general formula I:

(Formula Removed)

wherein, n = 1
R1 and R2 independently represent a hydrogen atom or a C^tois saturated or unsaturated alkyl group excluding the definition of R1 and R2 being simultaneously represented as a hydrogen atom,
R3 and R4 independently represent hydrogen or a hydroxyl group wherein R3 and R4 are not simultaneously hydrogen, and
X = an inorganic or organic anion.
4. A bioactive cationic amphiphile as represented by the general formula I:


(Formula Removed)

wherein, n = 1
both R1 and R2 are an unsaturated Ci8 alkyl group having one unsaturation,
R3 = R4 = hydroxyl group; and
X = an inorganic or organic anion.


5. A bioactive cationic amphiphile as claimed in claim 1, wherein X is selected from the group
consisting of hydrogen atom, tosyl group and acetate group.
6. A process for the preparation of a bioactive cationic amphiphile as claimed in claim 1, wherein
the steps comprising:
[a] coupling a saturated or unsaturated aliphatic bromide with a saturated or unsaturated aliphatic alkyl amine in a polar aprotic solvent in the presence of a base to obtain the corresponding aliphatic hydrophobic secondary amine;
[b] protecting both the terminal primary alcohol groups of an aliphatic alcohol containing two additional secondary hydroxyl groups with protecting groups in a polar aprotic solvent;
[c] reacting the secondary amine obtained in step (a) with the protected primary hydroxyl aliphatic polar intermediate obtained in step (b) in a polar aprotic solvent in the presence of an organic base to obtain a quaternized amphiphilic compound;
[d] passing the quaternized amphiphilic compound obtained in step (c) through anion-exchange column chromatography and eluting with a mixture of polar organic solvents to obtain the desired cationic amphiphile.

7. A process as claimed in claim 6, wherein the saturated aliphatic bromide is an aliphatic saturated alkyl bromide containing 12-18 carbon atoms.
8. A process as claimed in claim 6, wherein the saturated aliphatic alkyl amine is an aliphatic saturated alkyl amine containing 12-18 carbon atoms.
9. A process as claimed in claim 6, wherein the unsaturated aliphatic alkyl amine is an aliphatic unsaturated alkyl amine containing 18 carbon atoms having one double bond.
10. A process as claimed in claim 6, wherein the amino group is protected with, tert-butyloxycarbonyl or 9-fluorenylmethyloxycarbonyl or any other protective agents.

11. A process as claimed in claim 6, wherein the polar aprotic solvent in which the reaction is carried out is selected from the group consisting of dimethyl formamide, dimethyl sulphoxide, pyridine, triethyl amine, and mixtures thereof.
12. A process as claimed in claim 6, wherein the reaction is carried out in the presence of an inorganic alkali metal carbonate.
13. A process as claimed in claim 6, wherein the primary alcohol protecting group is tosyl chloride or mesyl chloride.
14. A process as claimed in claim 6, wherein the polar aprotic solvent used in step [a] is selected from the group consisting of dimethyl sulphoxide, N,N-dimefhyl formamide, ethyl acetate, and tetrahydrofuran.
15. A process as claimed in claim 6, wherein the reaction of step [a] is carried out at a temperature between 50 to 100 degree C.
16. A process as claimed in claim 6, wherein the protection of terminal primary hydroxy! groups of step [b] is carried out at a temperature between -10 to 50 degree C.
17. A process as claimed in claim 6, wherein the primary alcohol is erythrytol.
18. A process as claimed in claim 6, wherein the polar aprotic solvent used in step [c] is selected from the group consisting of dimethyl sulphoxide, N,N-dimethyl formamide, ethyl acetate, and tetrahydrofuran.
19. A process as claimed in claim 6, wherein the organic base used in step [c] is triethyl amine, pyridine or piperidine.
20. A process as claimed in claim 6, wherein the reaction of step [c] is carried out at a temperature between 50 to 100 degree C.
21. A process as claimed in claim 6, wherein the anion-exchange resin used in step [d] is a resin having a chloride or bromide ion available for ion exchange.

22. A process as claimed in claim 6, wherein the organic solvents used as ingredients of the polar eluent in step [d] are selected from the group consisting of methanol, ethanol, chloroform, dichloromethane, and ethyl acetate.
23. A bioactive cationic amphiphile and a process for the preparation thereof substantially as herein described with reference to the foregoing examples.


Documents:

01451-delnp-2003-abstract.pdf

01451-delnp-2003-claims.pdf

01451-delnp-2003-correspondence-others.pdf

01451-delnp-2003-description (complete).pdf

01451-delnp-2003-drawings.pdf

01451-delnp-2003-form-1.pdf

01451-delnp-2003-form-18.pdf

01451-delnp-2003-form-2.pdf

01451-delnp-2003-form-3.pdf

1451-DELNP-2003-Abstract-(17-12-2008).pdf

1451-DELNP-2003-Claims-(17-12-2008).pdf

1451-DELNP-2003-Correspondence-Others-(17-12-2008).pdf

1451-DELNP-2003-Drawings-(17-12-2008).pdf

1451-DELNP-2003-Form-1-(17-12-2008).pdf

1451-DELNP-2003-Form-2-(17-12-2008).pdf

1451-DELNP-2003-Form-3-(17-12-2008).pdf

1451-DELNP-2003-Petition-137-(17-12-2008).pdf


Patent Number 227577
Indian Patent Application Number 01451/DELNP/2003
PG Journal Number 05/2009
Publication Date 30-Jan-2009
Grant Date 13-Jan-2009
Date of Filing 11-Sep-2003
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110 001,INDIA
Inventors:
# Inventor's Name Inventor's Address
1 MAJETI BHARAT KUMAR RAFI MARG, NEW DELHI-110 001,INDIA
2 ARABINDDA CHAUDHURI RAFI MARG, NEW DELHI-110 001,INDIA
3 YERRAMSETTI RAMADAS RAFI MARG, NEW DELHI-110 001,INDIA
4 NALAM MADHUSUDHANA RAO RAFI MARG, NEW DELHI-110 001,INDIA
PCT International Classification Number A61K 31/00
PCT International Application Number PCT/IB02/01148
PCT International Filing date 2002-03-26
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/106,849 2002-03-27 U.S.A.