Amphiphilic poly (amino acid) linear block copolymers and nanoparticles thereof for drug delivery applications

Abstract

The present invention relates to the field of polymer chemistry, and more particularly to poly (amino acid) copolymers and their use in drug delivery applications. In particular, the present invention relates to a linear copolymer comprising a poly sarcosine block pSar comprising 15 to 99 sarcosine constituent units and a poly (amino acid) block pAA comprising 8 to 120 amino acid constituent units.

Description

Technical Field

[0001] The present invention relates to the field of polymer chemistry, and more particularly to poly(amino acid) copolymers and their use in drug delivery applications. Background Art

[0002] Active pharmaceutical ingredients (API) usually need to be mixed with one or more excipients to form a ready-to-use drug product. Excipients are inactive ingredients that usually have a specific function in the drug form: for example, they can act as binders, lubricants, coating agents or fillers. Depending on the indication for treatment, the drug can be administered by different routes (e.g., topical, oral, parenteral), and different routes require different final drug dosage forms, thus requiring the use of suitable excipients.

[0003] Polymeric excipients are widely used in formulating pharmaceuticals intended for various possible routes of administration. They include natural compounds such as cellulose, semisynthetic compounds such as cellulose derivatives, and synthetic polymers such as poly(ethylene glycol) (PEG), polylactic acid, or polyamides. Polymeric excipients can be used to modify the physical or chemical properties of the API, for example, to change its viscosity or to increase its solubility.

[0004] Amphiphilic block copolymers are particularly interesting excipients for dissolving hydrophobic APIs in water. They consist of at least one hydrophilic block covalently bound to a hydrophobic block, and self-assemble in water at a critical aggregation concentration (CAC) or higher to form nanoscale aggregates. These resulting supramolecular assemblies, also known as nanoparticles (NPs), typically have a size ranging from 10 to 100 nm, and can have various morphologies. For example, micelles have a spherical core-shell structure in which the hydrophobic blocks form a hydrophobic core that is stabilized by a hydrophilic shell composed of the hydrophilic blocks. The hydrophobic API can be loaded and sequestered in the core during the micellization process. API-loaded micelles prepared in a diluent commonly used for parenteral administration (e.g., normal saline) can increase the solubility of the API without the need for a cosolvent such as EL (polyoxyethylated castor oil), polyoxyethylated castor oil is known to cause a variety of adverse reactions. Another advantage is that the API is not covalently bound to the copolymer, so this drug form can be applied to a wide range of APIs.

[0005] Furthermore, in addition to increasing the aqueous solubility of APIs, nanoparticles also offer multiple advantages, such as preventing premature degradation of APIs, controlling their release, improving their bioavailability, and, for anti-tumor applications, enhancing the absorption of APIs into tumor tissues through passive targeting via the enhanced permeation and retention effect (EPR effect).

[0006] PEG is the most commonly used hydrophilic block due to its stealth effect. However, PEG is non-biodegradable and can induce immunogenic responses when administered in high doses or over a long period of time.

[0007] Polysarcosine (pSar) is a good alternative to PEG because they have similar properties such as hydrophilicity, stealth, and low toxicity, but pSar has the advantage of being biodegradable (because it is based on the endogenous amino acid derivative sarcosine (N-methylated glycine)).

[0008] Amphiphilic polysarcosine-poly(amino acid) copolymers have recently been developed due to their biodegradability and ability to self-assemble into nanoparticles in water.

[0009] US 10836869 discloses the use of copolymers of this type to solubilize hydrophobic molecules. These multi-block copolymers contain a large number of sarcosine and amino acid units, resulting in expensive synthesis and post-purification as well as industrial scale-up challenges.

[0010] Therefore, there remains a need for polymers that can solubilize hydrophobic APIs without causing adverse effects when used in drug delivery applications. Summary of the invention

[0011] Purpose of the invention

[0012] The invention relates to a linear copolymer, which comprises a polysarcosine block pSar containing 15 to 99 sarcosine constituent units and a poly (amino acid) block pAA containing 8 to 120 amino acid constituent units.

[0013] Preferably, the linear copolymer has a hydrophilic fraction f(pSar) ranging from 5% to 80%, preferably from 10% to 70%, wherein f(pSar) is the ratio of the number average molar mass of the pSar block to the number average molar mass of the copolymer as a percentage.

[0014] Preferably, the pAA block has a hydrophobicity coefficient H equal to or higher than -0.50, preferably equal to or higher than -0.25, preferably equal to or higher than 0.00, preferably equal to or higher than 0.50, more preferably equal to or higher than 0.80.

[0015] Preferably, the amino acid constituent units of the pAA block are derived from hydrophobic amino acids, which are preferably selected from alanine, valine, norleucine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline, tyrosine, their derivatives, protected hydrophilic amino acids and combinations thereof.

[0016] The derivative of the hydrophobic amino acid is preferably a protected hydrophobic amino acid.

[0017] Preferably, the copolymer is selected from the copolymers of formula I or II,

[0018]

[0019] in

[0020] x is the number of sarcosine constituent units, and is an integer ranging from 15 to 99,

[0021] y+z is the number of amino acid constituent units, and is an integer in the range of 8 to 120,

[0022] Group R y and R z are independently selected from amino acid side chain groups,

[0023] Group R 1a and R 1b are independently selected from H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl and heteroaryl,

[0024] Group R 2 is selected from H and a nitrogen protecting group.

[0025] Preferably, x is an integer in the range of 20-95, more preferably 24-85.

[0026] Preferably, y+z is an integer in the range of 8-110, more preferably 12-100.

[0027] Preferably, y+z is an integer in the range of 8-50, more preferably 9-45, even more preferably 12-40.

[0028] Preferably, y+z is an integer in the range of 55-110, more preferably 60-100.

[0029] Preferably, y is a value in the range of 0 to 120, more preferably 0 to 110, preferably 5 to 100, preferably 9 to 95, preferably 10 to 90.

[0030] Preferably, z is a value in the range of 0 to 120, more preferably 0 to 110, preferably 5 to 100, preferably 9 to 95, preferably 10 to 90.

[0031] At least one of z or y is not equal to zero.

[0032] Preferably, R y is the side chain of a hydrophobic L-amino acid, R z It is the side chain of a hydrophobic D-amino acid.

[0033] Preferably, Ry A side chain selected from the group consisting of L-leucine, L-phenylalanine, L-tyrosine, γ-benzyl-L-glutamate, γ-tert-butyl-L-glutamate and L-cyclohexylglycine.

[0034] Preferably, R z A side chain selected from the group consisting of D-leucine, D-phenylalanine, D-cyclohexylglycine, D-tyrosine, γ-benzyl-D-glutamate and γ-tert-butyl-D-glutamate.

[0035] The present invention also relates to a method for preparing the above linear copolymer by polymerization of sarcosine derivatives and amino acid derivatives, wherein the derivatives are represented by the following formula III and IV

[0036]

[0037] in

[0038] A is O or S,

[0039] R y , R z As defined above.

[0040] The present invention also relates to nanoparticles, which comprise the linear copolymer as described above or the linear copolymer prepared according to the method as described above.

[0041] Preferably, the nanoparticles further comprise at least one active compound, preferably selected from hydrophobic compounds, in particular hydrophobic active pharmaceutical ingredients.

[0042] The nanoparticles preferably satisfy at least one of the following conditions:

[0043] - a hydrodynamic diameter below 400 nm, preferably in the range of 5 to 200 nm;

[0044] - a polydispersity index lower than 0.70, preferably in the range of 0.02 to 0.70;

[0045] The loading efficiency of the active compound is greater than 20%, preferably greater than 30%.

[0046] The present invention further relates to a method for preparing the nanoparticles as described above, comprising the following steps:

[0047] - preparing an organic solution containing the copolymer of the invention,

[0048] - the organic solution is then mixed with the aqueous solution under stirring,

[0049] -The organic solvent is then removed.

[0050] Preferably, the nanoparticles further comprise an active compound, and the method comprises the steps of:

[0051] - preparing an organic solution containing the copolymer according to the invention and at least one active compound,

[0052] - the organic solution is then mixed with the aqueous solution under stirring,

[0053] -The organic solvent is then removed.

[0054] definition

[0055] The following are definitions of various terms used herein to describe the present disclosure, and are further illustrated by the embodiments, sub-embodiments and compounds disclosed herein. Unless otherwise specified in specific instances, these definitions apply to the terms used throughout this specification (whether used individually or as part of a larger group).

[0056] As used herein, the term "halogen" or "halo" refers to a fluorine, chlorine, bromine or iodine atom.

[0057] As used herein, the term "alkyl" refers to a straight or branched monovalent saturated hydrocarbon chain. 10 The term "alkyl" refers to an alkyl group containing 1 to 10 carbon atoms.

[0058] The term "alkenyl" has its usual meaning in the art and refers to an unsaturated hydrocarbon chain. 10 The term "alkenyl" refers to an alkenyl group containing 2 to 10 carbon atoms and containing one or more carbon-carbon double bonds.

[0059] The term "alkynyl" has its usual meaning in the art and refers to an unsaturated hydrocarbon chain. 10 The term "alkynyl" refers to an alkynyl group containing from 2 to 10 carbon atoms and containing one or more carbon-carbon triple bonds.

[0060] As used herein, the term "cycloalkyl" refers to a hydrocarbon ring. 10 The term "cycloalkyl" refers to a cycloalkyl group having 3 to 10 carbon atoms, including but not limited to cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0061] The term "aryl" as used in the present invention refers to an aromatic hydrocarbon group, which preferably contains 6 to 10 carbon atoms, contains one or more fused rings, and finally contains one or more substituents such as halogen, (C1-C6) alkyl, -O(C1-C6) alkyl. For example, aryl includes phenyl, benzyl or naphthyl.

[0062] The term "heteroaryl" as used in the present invention refers to an aryl group comprising one or more, particularly one or two, preferably one condensed hydrocarbon ring, wherein one or more, particularly one to four, advantageously one or two carbon atoms of the condensed hydrocarbon ring are each substituted by a heteroatom selected from a sulfur atom, an oxygen atom and a nitrogen atom, preferably selected from an oxygen atom and a nitrogen atom, particularly a nitrogen atom. It can be benzothiazolyl, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, quinolyl, isoquinolyl, quinoxalinyl or indolyl.

[0063] The term "unit" or "constitutional unit" in the present disclosure refers to a constitutional unit derived from polymerization of a monomer.

[0064] The term "linear copolymer" refers to a copolymer containing pSar blocks and pAA blocks, which has a linear structure such as shown in formula (I) or (II). The term "linear copolymer" does not include non-linear copolymers such as multi-arm star polymers (more specifically three-arm star copolymers).

[0065] The term "sarcosine constituent unit" or "sarcosinate unit" refers to a unit derived from a sarcosine monomer.

[0066] The term "amino acid constituent unit" or "amino acid unit" refers to a unit derived from an amino acid monomer.

[0067] The term "AA" is used to represent amino acids. In the present disclosure, the term "AA" does not include sarcosine.

[0068] Amino acids are represented by the formula NH2-CHR-CO2H, wherein R represents the side chain group of each amino acid. The amino acids used in the present invention can be natural amino acids or non-natural amino acids. The term "natural amino acids" refers to any naturally occurring amino acids that can be found in proteins or nature. These are L-alanine, L-arginine, L-asparagine, L-aspartate, L-cysteine, L-glutamate, L-glutamine, glycine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-proline, L-pyrrolysine, L-selenocysteine, L-serine, L-threonine, L-tryptophan, L-tyrosine and L-valine.

[0069] The term "unnatural amino acid" refers to any amino acid not included in the list of naturally occurring amino acids. Unnatural amino acids include amino acids in which the side chain "R" is chemically modified (e.g., by a functionalization or protecting group).

[0070] The term "amino acid side chain group" (also defined as "side chain group") refers to the group R on the α-carbon of any natural or non-natural AA, as defined herein. For example, the side chain group of L-alanine is a methyl group, and the side chain group of γ-benzyl-glutamate is the group -(CH2)2CO2CH2C6H5.

[0071] The term "D-amino acid" refers to an amino acid with the alpha carbon of AA in the D-configuration (also known as the D isomer), while the term "L-amino acid" refers to an amino acid with the alpha carbon of AA in the L-configuration (also known as the L isomer).

[0072] The term "poly (amino acid)" or "pAA" is used to indicate a block made of a linear polymer chain, wherein the constituent units are derived from amino acids or mixtures of amino acids and are covalently linked by peptide bonds. pAA can be formed by ring-opening polymerization of amino acid monomers. When only L-amino acid monomers are used, the resulting block is a poly (L-amino acid) block. When only D-amino acid monomers are used, the resulting block is a poly (D-amino acid) block. When a mixture of L-amino acids and D-amino acids is used in an unspecified order, the resulting block is a poly (L-amino acid-co-D-amino acid) block.

[0073] The term "Sar" is used to refer to sarcosine.

[0074] The term "polysarcosine" or "pSar" is used to denote a block made of a linear polymer chain, wherein the constituent units are derived from sarcosine and are covalently linked by peptide bonds.

[0075] The term "amino acid monomer" or "amino acid monomer" refers to an amino acid or any amino acid derivative that can be used in a polymerization process.

[0076] The term "sarcosine monomer" refers to sarcosine or any sarcosine derivative that can be used in the polymerization process.

[0077] The term "sarcosine derivative" or "amino acid derivative" refers to any reactive form of sarcosine or an amino acid that can be used in a polymerization process. For example, for ring-opening polymerization, the derivative can be an N-carboxyanhydride (NCA) of an amino acid or sarcosine or an N-thiocarboxyanhydride (NTA) of an amino acid or creatinine.

[0078] The term "initiator" or "polymerization initiator" in this disclosure refers to a molecule that reacts with monomers to form a compound that is capable of reacting in turn with other monomers to form a polymer by chain growth.

[0079] The term "terminator" refers to a compound that reacts with the end of a living polymer chain and stops chain growth.

[0080] The term "capping agent" refers to a compound that reacts with the N-terminal portion of a polymer chain to covalently bind a functional group (eg, -C(O)CH3).

[0081] The terms "drug loaded" and "loaded" refer to particles comprising an active compound (eg, an API) that is entrapped within the particle, for example, by encapsulation.

[0082] The expression "pharmaceutically acceptable" as used herein is intended to mean useful for preparing pharmaceutical compositions and generally safe and non-toxic in pharmaceutical use.

[0083] The terms “drug,” “active pharmaceutical ingredient,” “API,” “drug product” and their derivatives are used interchangeably to refer to a substance intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease.

[0084] According to the present invention, the terms "particle" and "nanoparticle" are used interchangeably to denote substances obtained by spontaneous self-assembly of block copolymers. For example, these nanoparticles may be micelles, polymer vesicles or complexes.

[0085] "Polymer micelle" means a substance characterized by a core-shell structure having a hydrophobic core and a hydrophilic shell formed by self-assembly of an amphiphilic copolymer.

[0086] "Polymersome" means a polymer-based vesicle, which is a substance having a double-layer structure surrounding an aqueous compartment, formed by the self-assembly of an amphiphilic copolymer.

[0087] "Polyplex" means a polymer system containing complex nucleic acid (eg, DNA or RNA) formed by electrostatic interactions between cationic groups of the polymer and the negatively charged nucleic acid.

[0088] It will be appreciated that any of the embodiments and preferred or advantageous disclosures described below may be combined with any of the other listed embodiments, preferred or advantageous disclosures.

[0089] method

[0090] NCA polymerization can be monitored by Fourier transform infrared spectroscopy (FTIR). For example, when the -1 The polymerization was considered complete when the NCA-related carbonyl band at 400 nm disappeared, which corresponds to the complete consumption of NCA.

[0091] The number of constituent units of each monomer of the pSar block and the pAA block can be determined by protons ( 1 H) determined by nuclear magnetic resonance (NMR).

[0092] The number average molar mass (M n ) and dispersity (D) can be determined by size exclusion chromatography (SEC).

[0093] The hydrodynamic diameter of the particle (D h ) and polydispersity index (PDI) can be determined by dynamic light scattering (DLS).

[0094] Loading efficiency (LE) can be determined using ultra-performance liquid chromatography (UPLC).

[0095] Loading content (LC) can be determined using SEC.

[0096] The aqueous solubility of the API can be determined by any experimental or analytical method (eg, UPLC).

[0097] The hydrophobicity coefficient H of the pAA block of the linear copolymer according to the present invention can be determined as follows.

[0098] The hydrophobicity coefficient of a block depends on the length of the block and / or its composition. The hydrophobicity coefficient H is defined by the following equation E1.

[0099] Equation E1: H = A log P / n

[0100] in,

[0101] - "H": hydrophobicity coefficient of the pAA block;

[0102] - "Alog P": is the simulated octanol-water partition coefficient of a PAA block having an amide functional group at its C-terminus and an acetamide functional group at its N-terminus, regardless of whether the amino acids of the PAA block are in the D-amino acid or L-amino acid configuration; and

[0103] - "n": is the number of AA units in the pAA block (ie in particular n=y or n=z, one of y or z being equal to 0).

[0104] When the pAA block consists of different AA units, ie in particular when both y and z are not equal to 0, the coefficient H is determined as the arithmetic mean of the coefficients H of the various AA unit types.

[0105] For example, in the case of a block P(AA1y-co-AA2z) derived from two amino acid monomers, the coefficient H is defined by the following equation E2.

[0106] Equation E2: HP(AA1y-co-AA2z) = (yHAA1+zHAA2) / (y+z)

[0107] For the pAA block, Alog P was determined by the prediction model for the octanol-water partition coefficient defined by Ghose and Crippen and calculated using Biovia Draw 19.1.NET.

[0108] -----Version-----

[0109] MDL.Draw.Editor 19.1.0.1792

[0110] -----Referenced and loaded assemblies-----

[0111] MDL.Cheshire:Loaded version = 5.1.0.22

[0112] MDL.CheshireLic:LoadedVersion=5.1.0.22

[0113] MDL.CsInline: Referenced and loaded version = 3.0.4.47

[0114] MDL.Draw.Clipboard: Referenced and loaded version = 19.1.0.1792

[0115] MDL.Draw.Editor:Loaded version = 19.1.0.1792

[0116] MDL.Draw.Foundation:Referenced and loaded version = 19.1.0.1792

[0117] MDL.Draw.Foundation.PPChemAPIIO:Loaded version = 19.1.0.1792

[0118] MDL.Draw.Renderer: Referenced and loaded version = 19.1.0.1792

[0119] MDL.Draw.TextServicesWrapper: Referenced and loaded version = 19.1.0.1792

[0120] nalpp:Referenced version = 19.1.0.1963

[0121] SandBar: Referenced and loaded version = 1.4.3.1

[0122] SandDock: Referenced and loaded version = 3.0.6.1.

[0123] The model of Ghose and Crippen refers to the model described in the following paper:

[0124] Ghose,AK;Crippen,GMAtomic Physicochemical Parameters for Three-Dimensional-Structure-Directed Quantitative Structure-ActivityRelationships.2.Modeling Dispersive and Hydrophobic Interactions.J.Chem.Inf.Comput.Sci.1987,27(1),21–35.https: / / doi.org / 10.1021 / ci00053a005.

[0125] Ghose, AK; Viswanadhan, VN; Wendoloski, J.J. Prediction of Hydrophobic (Lipophilic) Properties of Small Organic Molecules Using Fragmental Methods: An Analysis of ALOGP and CLOGP Methods.J.Phys.Chem.A 1998, 102(21), 3762–3772. https: / / doi.org / 10.1021 / jp980230o.

[0126] The specific scheme of each method is given in the examples. DETAILED DESCRIPTION

[0127] Surprisingly, it has been found that linear copolymers with a limited number of Sar units are able to increase the solubility of active compounds, preferably hydrophobic compounds such as hydrophobic APIs.

[0128] Advantageously, the linear copolymers according to the invention are cheaper than the copolymers of the prior art due to their easier synthesis. Furthermore, the industrial scale-up of the copolymers according to the invention can also be facilitated.

[0129] In particular, the linear copolymers according to the present invention are capable of improving the water solubility of hydrophobic compounds, such as hydrophobic APIs, by a factor of preferably greater than 100 times, preferably greater than 200 times, preferably greater than 500 times, preferably greater than 1000 times, preferably greater than 2000 times, more preferably greater than 3000 times, through their ability to self-assemble into nanoparticles.

[0130] Copolymer

[0131] The present invention relates to a linear copolymer comprising:

[0132] - a polysarcosine block pSar containing 15 to 99 sarcosine constituent units; and

[0133] - poly(amino acid) blocks pAA containing 8 to 120 amino acid building blocks.

[0134] One skilled in the art will appreciate that when the pAA blocks are formed from different AAs, the order of each AA unit can be statistical or controlled.

[0135] One advantage of the copolymers according to the invention is that they are stable, biocompatible and readily degradable in vivo.

[0136] According to the present invention, the pSar block of the copolymer is hydrophilic, while the pAA block has a lower hydrophilicity than the pSar block and therefore has a hydrophobic nature. These properties make the copolymer amphiphilic and enable it to form stable nanoparticles such as micelles. In addition, the nanoparticles formed by the copolymer of the present invention are biocompatible and easily degraded in vivo.

[0137] The amphiphilic properties of the pSar-pAA copolymers according to the invention can be used to form nanoparticles. Advantageously, said nanoparticles can encapsulate active compounds, for example to limit their degradation or to increase their solubility in water.

[0138] The limited number of constituent units of the pSar-pAA copolymers of the present invention enables easy and cost-attractive preparation of each block.

[0139] The pSar block contains chains of 15 to 99, preferably 20 to 95, preferably 24 to 85, more preferably 28 to 80 sarcosine units.

[0140] In a preferred embodiment, the pSar block contains a chain of 50 to 99, preferably 55 to 95, preferably 60 to 85, more preferably 65 to 80 sarcosine units.

[0141] In another preferred embodiment, the pSar block contains a chain of 15 to 50, preferably 18 to 45, preferably 22 to 40, more preferably 25 to 35 sarcosine units.

[0142] The AAs constituting pAA are preferably selected from the list disclosed further below. The selection is made to ensure that the pAA blocks obtained by polymerization have a lower hydrophilicity than the pSar blocks. The pAA blocks can be identified as hydrophobic blocks.

[0143] Preferably, the pAA block contains a chain of 8 to 120, preferably 8 or 9 to 110, preferably 12 to 100, more preferably 15 to 95 AA units.

[0144] In a preferred embodiment, the pAA block contains a chain of 8 to 50, preferably 9 to 45, preferably 12 to 40, more preferably 15 to 35 or even 20 to 25 AA units.

[0145] In another preferred embodiment, the pAA block contains a chain of 50 to 120, preferably 55 to 110, preferably 60 to 100, more preferably 65 to 95 AA units.

[0146] In a preferred embodiment, the linear copolymer comprises:

[0147] a polysarcosine block pSar containing 50 to 99, preferably 55 to 95, preferably 60 to 85, more preferably 65 to 80 sarcosine units; and

[0148] - a poly(amino acid) block pAA containing 8 to 50, preferably 9 to 45, preferably 12 to 40, more preferably 15 to 35 or even 20 to 25 AA units.

[0149] In a preferred embodiment, the linear copolymer comprises:

[0150] a polysarcosine block pSar containing 50 to 99, preferably 55 to 95, preferably 60 to 85, more preferably 65 to 80 sarcosine units; and

[0151] - a poly(amino acid) block pAA containing 50 to 120, preferably 55 to 110, preferably 60 to 100, more preferably 65 to 95 AA units.

[0152] In a preferred embodiment, the linear copolymer comprises:

[0153] a polysarcosine block pSar containing 15 to 50, preferably 18 to 45, preferably 22 to 40, more preferably 25 to 35 sarcosine units; and

[0154] - a poly(amino acid) block pAA containing 8 to 50, preferably 9 to 45, preferably 12 to 40, more preferably 15 to 35 or even 20 to 25 AA units.

[0155] In a preferred embodiment, the linear copolymer comprises:

[0156] a polysarcosine block pSar containing 15 to 50, preferably 18 to 45, preferably 22 to 40, more preferably 25 to 35 sarcosine units; and

[0157] - a poly(amino acid) block pAA containing 50 to 120, preferably 55 to 110, preferably 60 to 100, more preferably 65 to 95 AA units.

[0158] Advantageously, the copolymer comprises two or more blocks, wherein at least one block is pSar and at least one block is pAA.Preferably, the copolymer comprises two blocks, wherein one block is pSar and one is pAA.

[0159] Advantageously, the copolymer according to the invention has a hydrophilicity fraction f(pSar) ranging from 5% to 80%, preferably from 10% to 70%, preferably from 15% to 60%, more preferably from 20% to 50%. The hydrophilicity fraction f(pSar) may also be in the range of 5% to 60% or 10% to 55%. The hydrophilicity fraction f(pSar) is the number average molar mass (M n ) accounts for M of the copolymer n The proportion expressed as a percentage.

[0160] Advantageously, the copolymer has a hydrophobicity fraction f(pAA) ranging from 20% to 90%, preferably from 30% to 88%, preferably from 40% to 85%, more preferably from 50% to 80%. The hydrophobicity fraction is the M of the hydrophobic pAA block. n M n percentage.

[0161] Advantageously, the copolymers according to the invention have a number average molar mass M in the range of 500 g / mol to 50000 g / mol, preferably 800 to 45000 g / mol, preferably 1000 to 40000 g / mol, preferably 1200 to 35000 g / mol, more preferably 1400 to 32000 g / mol. n .

[0162] Advantageously, the copolymers according to the invention have a number average molar mass M in the range of 4500 to 50000 g / mol, preferably 4800 to 40000 g / mol, preferably 5200 to 30000 g / mol, preferably 5500 to 25000 g / mol, more preferably 6000 to 20000 g / mol. n .

[0163] Advantageously, the linear copolymer according to the invention has a dispersity D ranging from 1 to 2, preferably from 1.0 to 1.8, more preferably from 1.0 to 1.6.

[0164] Advantageously, the pAA block has a hydrophobicity index H equal to or higher than -0.50, preferably equal to or higher than -0.25, preferably equal to or higher than 0.00, preferably equal to or higher than 0.50, more preferably equal to or higher than 0.80. Typically, the pAA block has a index H ranging from -0.50 to 20.00, preferably from -0.25 to 18.00, preferably from 0.00 to 15.00, more preferably from 0.50 to 10.00 or even from 0.80 to 6.00. The hydrophobicity index H of the pAA block is determined by equation E1 or E2 as defined above.

[0165] The hydrophobic pAA block comprises, preferably consists of, natural or unnatural amino acid units (AA units), preferably as long as the AA units are hydrophobic compared to the Sar units of the pSar block. According to the invention, the pAA block does not comprise a sarcosine unit.

[0166] Advantageously, the amino acids of the pAA block are D-amino acids or / and L-amino acids, wherein D-amino acids refer to the D isomers of amino acids and L-amino acids refer to the L isomers of amino acids. Preferably, the amino acids of the pAA block are a mixture of D-amino acids and L-amino acids or only L-amino acids or only D-amino acids. Preferably, when the amino acids are a D-amino acid / L-amino acid mixture, the molar ratio between D-amino acids / L-amino acids ranges from 30 / 70 to 70 / 30, preferably from 40 / 60 to 60 / 40, preferably from 45 / 55 to 55 / 45, more preferably 50 / 50.

[0167] Advantageously, the AA of pAA is selected from hydrophobic amino acids, protected hydrophobic amino acids, protected hydrophilic amino acids and combinations thereof. The hydrophobic amino acids are preferably selected from alanine, valine, norleucine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline, tyrosine and combinations thereof.

[0168] Advantageously, the AA of pAA is an amino acid in which the side chain carries at least an aryl and / or heteroaryl group. The aryl and / or heteroaryl group may be originally contained in the side chain of the amino acid and / or added as a protecting group to the side chain of AA. For example, AA may be glutamic acid protected by a benzyl group.

[0169] Without being bound by any theory, it is believed that aryl and / or heteroaryl groups may participate in and facilitate the encapsulation of hydrophobic compounds, such as hydrophobic APIs, by the linear copolymers of the present invention.

[0170] The functional groups on the side chains of AA can be protected by various protecting groups. Preferably, the protecting groups at least include aryl and / or heteroaryl groups.

[0171] Functional groups such as hydroxyl, amine group, aldehyde group and carboxylic acid group of amino acid side chain can be protected by ester, carbonate, sulfonate, allyl ester, ether, silyl ether, alkyl ether, aryl alkyl ether, alkoxyalkyl ether. Esters used to protect hydroxyl according to the present invention can be formates, acetates, propionates, butyrates, valerates, crotonates, benzoates, benzoylformate, chloroacetates, trifluoroacetates, methoxyacetates, triphenylmethoxyacetates, p-chlorophenoxyacetates, 3-phenylpropionate, 4-oxopentanoate, 4,4-(ethylenedithio)pentanoate, pivaloate (pivaloate) (trimethylacetate), crotonates, 4-methoxy-crotonates, benzoates, p-benzylbenzoate, 2,4,6-trimethylbenzoate.

[0172] Advantageously, when a carbonate is used to protect the hydroxyl group, the carbonate is selected from 9-fluorenylmethyl carbonate, ethyl carbonate, 2,2,2-trichloro-ethyl carbonate, 2-(trimethylsilyl)ethyl carbonate, 2-(phenylsulfonyl)ethyl carbonate, vinyl carbonate, allyl carbonate and p-nitrobenzyl carbonate.

[0173] Advantageously, when a silyl ether is used to protect the hydroxyl group, the silyl ether is selected from trimethylsilyl ether, triethylsilyl ether, tert-butyldimethylsilyl ether, tert-butyldiphenylsilyl ether, triisopropylsilyl ether and other trialkylsilyl ethers.

[0174] Advantageously, when alkyl ethers, alkoxyalkyl ethers and aryl alkyl ethers are used to protect the hydroxyl group: the alkyl ether is selected from methyl ether, benzyl ether, p-methoxybenzyl ether, 3,4-dimethoxybenzyl ether, trityl ether, tert-butyl ether and allyl ether or derivatives thereof; the alkoxyalkyl ethers including acetals are selected from methoxymethyl ether, methylthiomethyl ether, (2-methoxyethoxy)methyl ether, benzyloxymethyl ether, β-(trimethylsilyl)ethoxymethyl ether and tetrahydropyran-2-yl ether; the aryl alkyl ether is selected from benzyl ether, p-methoxybenzyl (MPM) ether, 3,4-dimethoxybenzyl ether, o-nitrobenzyl ether, p-nitrobenzyl ether, p-halobenzyl ether, 2,6-dichlorobenzyl ether, p-cyanobenzyl ether, 2- and 4-picolyl ether.

[0175] Advantageously, the amine group of the AA side chain can be protected by arylalkylamine, carbamate, allylamine, amide and its derivatives, including tert-butoxycarbonylamino (-NHBOC), ethoxycarbonylamino, methoxycarbonylamino, trichloroethoxycarbonylamino, allyloxycarbonylamino (-NHAlloc), benzyloxycarbonylamino (-NHCbz), allylamino, benzylamino (-NHBn), fluorenylmethylcarbonyl (-NHFmoc), formamide, acetamide, chloroacetamide, dichloroacetamide, trichloroacetamide, phenylacetamide, trifluoroacetamide, benzamide, tert-butyldiphenylsilyl.

[0176] Advantageously, the aldehyde group of the AA side chain can be protected by acyclic acetals, hydrazones, imines, more specifically by dimethyl acetal, diethyl acetal, diisopropyl acetal, dibenzyl acetal, bis(2-nitrobenzyl) acetal, 1,3-dioxane, 1,3-dioxolane, semicarbazone and derivatives thereof.

[0177] Advantageously, the carboxylic acid group of the AA side chain can be protected by optionally substituted C1-C6 aliphatic esters, optionally substituted aryl esters, silyl esters, activated esters, amides, hydrazides, such as but not limited to ethyl, propyl, isopropyl, butyl, isobutyl, benzyl and phenyl esters, each of which is optionally substituted. Other protected carboxylic acids include oxazolines and orthoesters.

[0178] Those skilled in the art will appreciate that the use of protecting groups on the functional groups of the side chains of AA can convert the affinity of AA from hydrophilic to hydrophobic.

[0179] Hydrophilic AAs that may be subsequently protected to become hydrophobic include cysteine, tyrosine, serine, threonine, aspartic acid, glutamic acid, asparagine, lysine, histidine, arginine, glycine, and glutamine.

[0180] The protecting group is preferably selected from: alkyl, alkoxyalkyl and arylalkyl ethers, such as trityl, tert-butyl, benzyl; esters, such as trifluoroacetate; arylalkylamines, carbamates, allylamines, amides and derivatives thereof, including tert-butoxycarbonylamino; acetates.

[0181] Protected hydrophilic AAs preferably include β-trityl-asparagine, β-benzyl-aspartate, S-benzyl-cysteine, cyclohexylglycine, γ-benzyl-glutamate, γ-tert-butyl-glutamate, ε-trifluoroacetyl-lysine, ε-Boc-lysine, ε-benzyl-lysine, β-benzyl-serine, O-acetyl-tyrosine and O-benzyl-tyrosine. A preferred protected hydrophilic AAs is γ-benzyl-glutamate.

[0182] Preferably, the linear copolymer is selected from the copolymers of formula I or II,

[0183]

[0184] in

[0185] x is the number of sarcosine constituent units, and is an integer ranging from 15 to 99,

[0186] y+z is the number of amino acid constituent units, and is an integer in the range of 8 to 120,

[0187] Group R y and R z are independently selected from amino acid side chain groups,

[0188] Group R 1a and R 1b are independently selected from H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl and heteroaryl,

[0189] Group R 2 is selected from H and a nitrogen protecting group.

[0190] When the amino acid contains a cyclic side chain group, the group R y and / or R z It is also connected to the N atom of the constituent unit. Thus, the hydrogen atom shown in formulae (I) and (II) is naturally missing.

[0191] "x" is the total number of sarcosine constituent units in the pSar block. Preferably, x is an integer in the range of 20 to 95, preferably 24 to 85, more preferably 28 to 80.

[0192] In a preferred embodiment, x is an integer in the range of 50 to 99, preferably 55 to 95, preferably 60 to 85, more preferably 65 to 80 sarcosine units.

[0193] In another preferred embodiment, x is an integer in the range of 15 to 50, preferably 18 to 45, preferably 22 to 40, more preferably 25 to 35 sarcosine units.

[0194] "y+z" is the total number of amino acid constituent units. Preferably, y+z is an integer in the range of 8 or 9 to 110, preferably 12 to 100, more preferably 15 to 95.

[0195] In a preferred embodiment, y+z is an integer in the range of 8 to 50, preferably 9 to 45, preferably 12 to 40, more preferably 15 to 35 or even 20 to 25.

[0196] In a preferred embodiment, y+z is an integer in the range of 50 to 120, preferably 55 to 110, preferably 60 to 100, more preferably 65 to 95.

[0197] Advantageously,

[0198] -x ranges from 50 to 99, preferably from 55 to 95, more preferably from 60 to 85, even more preferably from 65 to 80, and

[0199] -y+z ranges from 8 to 50, preferably from 9 to 45, more preferably from 12 to 40, even more preferably from 20 to 25.

[0200] Advantageously,

[0201] -x ranges from 50 to 99, preferably from 55 to 95, more preferably from 60 to 85, even more preferably from 65 to 80, and

[0202] -y+z ranges from 50 to 120, preferably from 55 to 110, more preferably from 60 to 100, even more preferably from 65 to 95.

[0203] Advantageously, when x ranges from 50 to 99, y+z ranges from 50 to 120. Advantageously, when x ranges from 55 to 95, y+z ranges from 55 to 110. Advantageously, when x ranges from 60 to 85, y+z ranges from 60 to 100. Advantageously, when x ranges from 65 to 80, y+z ranges from 65 to 95.

[0204] Advantageously,

[0205] -x ranges from 15 to 50, preferably from 18 to 45, more preferably from 22 to 40, even more preferably from 25 to 35, and

[0206] -y+z ranges from 8 to 50, preferably from 9 to 45, more preferably from 12 to 40, even more preferably from 15 to 35, even more preferably from 20 to 25.

[0207] Advantageously, when x ranges from 15 to 50, y+z ranges from 8 to 50. Advantageously, when x ranges from 18 to 45, y+z ranges from 9 to 45. Advantageously, when x ranges from 22 to 40, y+z ranges from 12 to 40. Advantageously, when x ranges from 25 to 35, y+z ranges from 15 to 35 or even from 20 to 25.

[0208] Advantageously,

[0209] -x ranges from 15 to 50, preferably from 18 to 45, more preferably from 22 to 40, even more preferably from 25 to 35, and

[0210] -y+z ranges from 50 to 120, preferably from 55 to 110, more preferably from 60 to 100, even more preferably from 65 to 95.

[0211] "y" is the number of AA units in the pAA subblocks comprised by the pAA block. Preferably, "y" is a value in the range of 0 to 120, preferably 0 to 110, preferably 5 to 100, preferably 9 to 95, preferably 10 to 90, preferably 15 to 85, preferably 18 to 80, preferably 20 to 75, preferably 25 to 70, more preferably 30 to 65.

[0212] "z" is the number of AA units in the pAA subblocks comprised by the pAA block. Preferably, "z" is a value in the range of 0 to 120, preferably 0 to 110, preferably 5 to 100, preferably 9 to 95, preferably 10 to 90, preferably 15 to 85, preferably 18 to 80, preferably 20 to 75, preferably 25 to 70, more preferably 30 to 65.

[0213] Advantageously, y is a value in the range of 5 to 50 and z is a value in the range of 0 to 50. Preferably, y is in the range of 9 to 45 and z is in the range of 0 to 45. Preferably, y is in the range of 9 to 40 and z is in the range of 5 to 45. Preferably, y is in the range of 10 to 40 and z is in the range of 9 to 45. Preferably, y is in the range of 10 to 40 and z is in the range of 10 to 40.

[0214] In a preferred embodiment, y or z is 0. Preferably, z is 0 and y ranges from 8 to 120, preferably 9 to 110, preferably 12 to 100, preferably 15 to 95. In a preferred embodiment, z is 0 and y is an integer in the range of 8 to 50, preferably 9 to 45, preferably 12 to 40, more preferably 15 to 35. In a preferred embodiment, z is 0 and y is an integer in the range of 50 to 120, preferably 55 to 110, preferably 60 to 100, more preferably 65 to 95.

[0215] Advantageously, the pAA block has a hydrophobicity index H equal to or higher than -0.50, preferably equal to or higher than -0.25, preferably equal to or higher than 0.00, preferably equal to or higher than 0.50, more preferably equal to or higher than 0.80. Typically, the pAA block has a index H ranging from -0.50 to 20.00, preferably from -0.25 to 18.00, preferably from 0.00 to 15.00, more preferably from 0.50 to 10.00 or even from 0.80 to 6.00. The hydrophobicity index H of the pAA block is determined by the following equation:

[0216] - equation E1 as defined above when one of y or z is 0, wherein "n" corresponds to "y" when z=0, or corresponds to "z" when y=0; or

[0217] - E2 as defined above when both y and z are not equal to 0.

[0218] In formula (I) and (II), the side chains of the AA units of the pAA blocks are composed of groups R y and R z Indicates. y and R z The group is a side chain of the AA unit defined above. y and R z Not for H.

[0219] Advantageously, the pAA block has R y and R z The units of the group are independently selected from natural or unnatural amino acids, as long as the side chains of the hydrophobic pAA block are hydrophobic.

[0220] Preferably, R y and / or R z The group contains at least an aryl group and / or a heteroaryl group. The aryl group and / or the heteroaryl group may be located in the protective group of the amino acid and / or AA. For example, R y and / or R z The group may be the side chain of benzyl-protected glutamic acid, ie, the side chain of γ-benzyl-D-glutamate.

[0221] The functional groups on the side chains of AA can be protected by various protecting groups, as disclosed above. Preferably, the protecting groups at least include aryl and / or heteroaryl groups.

[0222] With R y and R z The α-carbon of the AA unit of the group may have a D-configuration or an L-configuration. y or R z When designated as L- or D-, preferably L-AA or D-AA, it means that the group R y or R z The carbon of is in L-configuration or D-configuration. y or R z When designated as L-AA or D-AA, it means R y or R z In the L configuration or D configuration of the corresponding AA.

[0223] Advantageously, with R y and R z The α-carbon of is independently in the D-configuration or the L-configuration. y and R z The α-carbon of has different configurations. Preferably, R yis the side chain of hydrophobic L-AA, R z is a side chain of hydrophobic D-AA. y is the side chain of hydrophobic D-AA, R z It is the side chain of hydrophobic L-AA.

[0224] Preferably, R y and R z At least one of them is a side chain of AA having at least an aromatic group and / or a heteroaromatic group. In particular, R y and R z Each of them is a side chain of AA having at least an aryl group and / or a heteroaryl group.

[0225] Preferably, R y and R z independently selected from -CH3, -CH(CH3)2, -(CH2)3-CH3, -CH2-CH(CH3)2, -CH(CH3)-CH2-CH3, -CH2-CH2-S-CH3, -CH2-C6H5, -CH2-(1H-indol-3-yl), -CH2-CH2-CH2-, -CH2-4-(OH)C6H4, -CH2-C(O)-NH-C(C6H5)3, -CH2-C(O)-OCH2-C6H5, -CH2-S-CH2-C6H5, -C6H 11 , -CH2-CH2-C(O)-O-CH2-C6H5, -CH2-CH2-C(O)-OC(CH3)3, -(CH2)4-NH-C(O)-CF3, -CH2-O-CH2-C6H5, -CH2-4-(acetyl)-C6H5 and -CH2-C6H4-O-CH2-C6H5.

[0226] Preferably, R y and R z independently selected from -CH2-CH(CH3)2, -CH2-C6H5, -CH2-4-(OH)C6H4, -CH2-CH2-C(O)-O-CH2-C6H5, -CH2-CH2-C(O)-OC(CH3)3 and -C6H 11 .

[0227] Preferably, R y and R zIndependently selected from -CH2-C6H5, -CH2-4-(OH)C6H4, -CH2-CH2-C(O)-O-CH2-C6H5, -CH2-C(O)-NH-C(C6H5)3, -CH2-C(O)-OCH2-C6H5, -CH2-S-CH2-C6H5, -CH2-O-CH2-C6H5, -CH2-4-(acetyl)-C6H5 and -CH2-C6H4-O-CH2-C6H5.

[0228] Preferably, R y and R z Side chains independently selected from L-leucine, L-phenylalanine, L-tyrosine, γ-benzyl-L-glutamate, γ-tert-butyl-L-glutamate, L-cyclohexylglycine, D-leucine, D-phenylalanine, D-cyclohexylglycine, D-tyrosine, γ-benzyl-D-glutamate, and γ-tert-butyl-D-glutamate.

[0229] In some embodiments, each R y R is independently a side chain of L-leucine, L-phenylalanine, L-tyrosine, γ-benzyl-L-glutamate, or γ-tert-butyl-L-glutamate. z is independently a side chain of D-leucine, D-phenylalanine, D-cyclohexylglycine, D-tyrosine, γ-benzyl-D-glutamate, or γ-tert-butyl-D-glutamate. y and R z are independently -CH2-CH2-C(O)-O-CH2-C6H5, -CH2-CH2-C(O)-OC(CH3)3. Preferably, each R y is independently a side chain of γ-benzyl-L-glutamate or γ-tert-butyl-L-glutamate. z are independently the side chains of γ-benzyl-D-glutamate and γ-tert-butyl-D-glutamate.

[0230] Preferably, R 2is a nitrogen protecting group. The nitrogen protecting group can be selected from any group known in the prior art. The nitrogen protecting group includes, but is not limited to, arylalkylamine, carbamate, allylamine, amide and derivatives thereof, including tert-butyloxycarbonylamino (-NHBOC), ethoxycarbonylamino, methoxycarbonylamino, trichloroethoxycarbonylamino, allyloxycarbonylamino (-NHAlloc), benzyloxycarbonylamino (-NHCbz), allylamino, benzylamino (-NHBn), fluorenylmethylcarbonyl (-NHFmoc), formamido, acetamido, chloroacetamido, dichloroacetamido, trichloroacetamido, phenylacetamido, trifluoroacetamido, benzamido, tert-butyldiphenylsilyl.

[0231] Preferably, R 1a and R 1b are independently selected from H, (C1-C 10 )alkyl, (C2-C 10 ) olefin group, (C2-C 10 ) alkynyl, (C3-C 10 )cycloalkyl, (C5-C 10 ) aryl, (C4-C 10 ) heteroaryl. Preferably, R 1a and R 1b independently selected from H, (C1-C6) alkyl, (C2-C8) alkene, (C2-C 10 ) alkynyl, (C3-C 10 )cycloalkyl, (C5 or C6)aryl, (C4 or C5)heteroaryl. More preferably, R 1a and R 1b Independently selected from H, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and phenyl and / or benzyl groups optionally substituted by halogen, -CH3, -CF3, -OCH3, OH.

[0232] Preferably, R 1a For H, R 1b is neopentyl, and R 2 Selected from H or -C(O)CH3.

[0233] Advantageously, the group NR 1a R 1b is a residue derived from a polymerization initiator and connected to the first block.

[0234] Advantageously, the group R 2 is the residue derived from a terminator or end-capping agent which is attached to the last block formed during the synthesis of the linear copolymer.

[0235] According to a preferred embodiment of the present invention, when the first block is pSar and the last block is pAA, the linear copolymer is defined by the general formula I, wherein

[0236] Group R 1a and R 1b are independently selected from H, alkyl or aryl,

[0237] Group R 2 Selected from H, alkyl and the following groups: Selected from R 3 OC(O)-,,R 3 C(O)-、R 3 SO2- group,

[0238] Where R 3 Selected from (C1-C 10 )alkyl, (C2-C 10 ) olefin group, (C2-C 10 ) alkynyl, (C3-C 10 )cycloalkyl, (C5-C 10 ) aryl and (C4-C 10 ) heteroaryl.

[0239] According to a preferred embodiment of the present invention, when the first block is pAA and the last block is pSar, the linear copolymer is defined by the general formula II, wherein

[0240] Group R 1a and R 1b are independently selected from H, alkyl or aryl,

[0241] Group R 2 Selected from H, alkyl and the following groups: Selected from R 3 OC(O)-,,R 3 C(O)-、R 3 SO2- group,

[0242] Where R 3 Selected from (C1-C 10 )alkyl, (C2-C 10 ) olefin group, (C2-C 10 ) alkynyl, (C3-C 10 )cycloalkyl, (C5-C 10 ) aryl and (C4-C 10 ) heteroaryl.

[0243] Preferably, the group R in formula I or II 2 is a residue derived from a capping agent selected from an alkyl group and a group selected from R 3 OC(O)-、R 3 C(O)-、R 3SO2-. Preferably, R 3 Selected from H, (C1-C6) alkyl, (C2-C8) olefin, (C2-C 10 ) alkynyl, (C3-C 10 )cycloalkyl, (C5 or C6)aryl, (C4 or C5)heteroaryl. More preferably, R 3 Selected from methyl, ethyl, propyl, butyl and trifluoromethyl.

[0244] Preferably, the copolymer is selected from the copolymers C1 to C12 of the embodiments represented by formula (I') or (II').

[0245]

[0246] in

[0247] R 1a H and R 1b -CH2-C(CH3)3

[0248] R 2 is H or CH3C(O)-, and

[0249] x and "y+z" have different values ​​depending on the copolymer according to the invention described in the examples hereinafter.

[0250] Method for preparing copolymers

[0251] The present invention also relates to a method for preparing a linear copolymer. Preferably, the linear copolymer is synthesized by polymerization of a sarcosine derivative and an amino acid derivative. Preferably, the copolymer is synthesized by ring-opening polymerization, wherein the Sar derivative and the AA derivative are N-carboxylic anhydride (NCA) or thiocarboxylic anhydride (NTA) of the corresponding constituent units, respectively.

[0252] Advantageously, the synthesis of the linear copolymers according to the invention having a limited number of Sar and / or AA constituent units is easy and therefore cheaper compared to the prior art. The industrial scale-up of the preparation of the linear copolymers according to the invention is also facilitated.

[0253] According to the present invention, the Sar derivatives and AA derivatives correspond to compounds represented by the following formulae III and IV, respectively:

[0254]

[0255] Where A is O or S; R y , R z As mentioned above.

[0256] The compounds of formula III and IV, also called derivatives, are NCA when A is O and NTA when A is S.

[0257] The compound of formula III can be a monomer for preparing pSar blocks. It is also called NCA / NTA of sarcosine or sarcosine NCA / NTA or Sar NCA / NTA.

[0258] The compound of formula IV can be a monomer used to prepare a pAA block. Compound IV is referred to as IV when used to prepare a unit of a pAA block having a superscript y. y Similarly, compound IV z Units used to prepare pAA blocks with superscript z. y and R z As mentioned above. It is also called NCA / NTA of amino acid or amino acid NCA / NTA or AA NCA / NTA.

[0259] The linear copolymers of the present invention can be prepared by a process comprising:

[0260] - step a): forming a first block by ring-opening polymerization by reacting a first derivative in the presence of a polymerization initiator, wherein the first derivative is selected from compound III or at least one compound IV,

[0261] - optional step b): isolating the first block formed in step a),

[0262] - step c): forming the last block by mixing a second derivative chosen from compound III or at least one compound IV with the first block obtained in step a) or optionally the first block isolated in step b),

[0263] wherein the first derivative and the second derivative are different and one of them is compound III,

[0264] - Step d): recovery of the copolymer.

[0265] Advantageously, step d) of recovering the linear copolymer of the invention comprises isolating and purifying the copolymer obtained in step c). Preferably, step d) of recovery is carried out after the derivative introduced in step c) has been consumed.

[0266] Advantageously, when the last block is formed by adding the derivative to the mixture obtained in step a), step c) is carried out after the derivative introduced in step a) has been consumed.

[0267] Advantageously, the derivative different from sarcosine introduced in step a) or c) is selected from two AAs of formula IV. Preferably, one amino acid has a residue with R y The group of formula IV y , another AA has a R z The group of formula IV z . With R y and R z The carbon atoms may be in the D-configuration or the L-configuration.

[0268] Advantageously, the copolymer can be prepared by a one-pot process, wherein the first block formed in step a) is not isolated in the optional step b). In this embodiment, the last block is formed by mixing the second derivative directly into the mixture obtained in step a) after the derivative introduced in step a) has been consumed.

[0269] In one embodiment, the derivative introduced in step a) is compound III and the derivative introduced in step c) is compound IV.

[0270] In another embodiment, the derivative introduced in step a) is compound IV and the derivative introduced in step c) is compound III.

[0271] Preferably, steps a) and / or c) are carried out under reduced pressure or under atmospheric pressure.

[0272] Preferably, steps a) and / or c) are carried out at a temperature ranging from 0°C to 80°C, preferably from 5°C to 60°C, preferably from 10°C to 50°C, preferably from 15°C to 40°C, preferably from 20°C to 30°C, more preferably from 22°C to 28°C.

[0273] Advantageously, step a) and / or c) is carried out in a solvent selected from N,N-dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, water, acetonitrile, ethyl acetate. Preferably, the solvent is N,N-dimethylformamide.

[0274] Preferably, the solvent of step a) is the same as the solvent of step c).

[0275] In a preferred embodiment, the derivative is introduced into steps a) and / or c) as a solid powder.

[0276] In some embodiments, the derivative is introduced into step a) and / or c) as a solution in a solvent. Preferably, the solvent of the derivative solution is the same as the solvent used for the reaction.

[0277] Preferably, the polymerization initiator is an amine, preferably having the formula (R 1a )(R 1b )NH, where R1a and R 1b As mentioned above.

[0278] Preferably, the molar ratio of the first derivative to the polymerization initiator ranges from 5 to 120, preferably from 20 to 110, preferably from 30 to 100, more preferably from 40 to 95.

[0279] Advantageously, the method for preparing the copolymer may also comprise a termination step after the consumption of the derivative introduced in step c) and before step d). Preferably, the termination step corresponds to the consumption of all the derivatives introduced in step c). Advantageously, the termination step may be performed with a terminator known in the art. Preferably, the termination step is performed by protonation. Thus, R 2 Preferably H. Optionally, the terminator may be selected from water, an acid such as acetic acid, trifluoromethanesulfonic acid or trifluoroacetic acid.

[0280] Preferably, the preparation method includes a step of carrying out end-capping by adding an end-capping agent and any other reagents required for the reaction before or after step d). When the end-capping step is before step d), the introduction of the end-capping agent is carried out after the derivative introduced in step c) is consumed. In this embodiment, the end-capping step can be carried out after the termination step. In this embodiment, the end-capping agent can also be a terminator. Thus, the termination step and the end-capping are carried out in a single step.

[0281] When the end-capping step is subsequent to step d), said end-capping step is carried out by mixing the copolymer with the end-capping agent in the presence of a solvent as defined above.

[0282] In any case, preferably the end-capping step is carried out at a temperature ranging from 0°C to 80°C, preferably 5°C to 60°C, preferably 10°C to 50°C, more preferably 15°C to 40°C, preferably 20°C to 30°C, more preferably 22°C to 28°C.

[0283] Advantageously, the end-capping step is carried out at the same temperature as step a) and / or c).

[0284] The end-capping step is preferably performed by adding a 2 X is carried out by a capping agent. 2 As described above, and X is a leaving group. Preferably, X is a leaving group known to the skilled person. Preferably, X is selected from Cl-, I-, Br-, CF3C(O)-, CH3C(O)-.

[0285] Nanoparticles

[0286] Another aspect of the invention relates to nanoparticles comprising the linear copolymer as defined above.The nanoparticles are formed by self-assembly of the linear copolymer according to the invention.

[0287] Advantageously, the nanoparticles comprise a linear copolymer and at least one active compound.

[0288] According to one aspect of the invention, the nanoparticles according to the invention have a hydrodynamic diameter D below 900 nanometers (nm), preferably below 600 nm, preferably in the range of 1 to 600 nm, preferably 2 to 500 nm, preferably 5 to 300 nm, preferably 8 to 200 nm, more preferably 10 to 110 nm. h .

[0289] Preferably, the nanoparticles have a polydispersity index PDI below 0.7, preferably in the range of 0.02 to 0.70, preferably 0.05 to 0.60, more preferably 0.10 to 0.50.

[0290] Advantageously, the active compound can be bound to the nanoparticles by non-covalent interactions. Preferably, the active compound can be bound to the nanoparticles by non-covalent interactions or absorbed on their surfaces. Preferably, the active compound is bound to the nanoparticles by hydrophobic interactions.

[0291] Preferably, the active compound is hydrophobic.The compound may be an active pharmaceutical ingredient (API) and a nucleic acid (eg siRNA, miRNA).

[0292] According to a preferred embodiment, the nanoparticles comprise at least two active compounds, preferably at least two APIs.

[0293] Preferably, the hydrophobic compound is loaded within the nanoparticles.

[0294] The hydrophobic compound, preferably the hydrophobic API, is a compound having a water solubility of less than 10 g / L.

[0295] Nanoparticles containing the copolymer and the API are called drug-loaded nanoparticles.

[0296] Advantageously, the drug-loaded nanoparticles according to the present invention have at least one of the following advantages:

[0297] - prevent or delay API degradation,

[0298] -Control API release,

[0299] - Improve API bioavailability, and

[0300] - For anti-tumor applications, the absorption of API into tumor tissue is enhanced by passive targeting via the high permeability and retention effect (EPR effect).

[0301] Preferably, the API is selected to be suitable for targeting a disease selected by a person skilled in the art. Examples of API include anticancer agents, antibacterial agents, antiviral agents, anti-inflammatory agents, immunosuppressive drugs, steroid drugs, hormone drugs and anti-angiogenic agents. These drug molecules can be used alone or in combination of two or more.

[0302] Preferably, the API is selected from 10,11-methylenedioxycamptothecin, 10-hydroxy-7-ethylcamptothecin (SN38), 2-chloroadenosine trimetrexate, 5-azacytosine, 5-azadeoxycytosine, 5'-deoxyfluorouridine, 5-fluorouracil (5-FU), 6-mercaptopurine, 6-thioguanine, 9-aminocamptothecin, 9-nitrocamptothecin, acyclovir, aldesleukin, allopurinol, amantadine, amiodarone, aminopterin, amsacrine, asparaginase, bleomycin, budesonide, busulfan, camptothecin, capecitabine, carboplatin, celecoxib, CI-973, cisplatin, gram Ladribine, CPT-11, curcumin, cyclophosphamide, cyclosporine, cytarabine, dacarbazine, daunorubicin, deoxycytidine, docetaxel, doxorubicin, eniluracil, epirubicin, epothilone AE, etoposide, etoposide phosphate, etoposide phosphate, furanfluorouracil, ganciclovir, gemcitabine (gemcitabine), ifosphamidemefosphamide, irinotecan, JM-216, karenitecin, lamivudine, L-phenylalanine mustard mustard), methotrexate, methylene-10-deazaminopterin (methylene-10-deazaminopterin, MDAM), mitomycin, mitoxantrone, ormaplatin, oxaliplatin, paclitaxel, perfosfamide, picoplatin, platinum-DACH, methyl procarbazine, rapamycin, resveratrol, rimantadine, sitraplatin, semustine, tamoxifen, TAS103, temozolomide, tetraplatin, raltitrexed, topotecan, retinoic acid, clofosfamide carmustine, UFT, valacyclovir, vinblastine, vincristine, vindesine, vinorelbine, zidovudine and a combination thereof or a pharmaceutically acceptable salt thereof.

[0303] One aspect of the present invention is the use of drug-loaded nanoparticles as a medicament, preferably in the treatment of cancer. A preferred aspect of the present invention is a method of treating or preventing a disease or condition, such as cancer, comprising administering the nanoparticles according to the present invention to a patient in need thereof. Another preferred aspect of the present invention is the use of the nanoparticles according to the present invention in the preparation of a medicament for therapeutic use, preferably for the treatment of cancer. In particular, the hydrophobic API may be a cytotoxic agent, such as a taxane, more particularly paclitaxel.

[0304] Preferably, the hydrophobic API is advantageously an anticancer drug, more preferably selected from paclitaxel (Taxol), doxorubicin, daunomycin, vinblastine, docetaxel (Taxotere), 10-hydroxy-7-ethylcamptothecin (SN38).

[0305] Advantageously, the nanoparticles improve the solubility of the hydrophobic API. Water solubility refers to the concentration at which a compound dissolves in water. For a hydrophobic API loaded in nanoparticles, the water solubility of the API is considered to be the concentration of the API in the suspension of the nanoparticles [API], although technically it is not in solution. Advantageously, the nanoparticles improve the water solubility of the hydrophobic API by a factor greater than 100 times, preferably greater than 200 times, preferably greater than 500 times, preferably greater than 1000 times, preferably greater than 2000 times, and more preferably greater than 3000 times.

[0306] Preferably, the API in the API-loaded nanoparticles has a water solubility denoted as [API] of 0.2 to 2.0 g / L, preferably 0.3 to 1.5 g / L, preferably 0.4 to 1.5 g / L, more preferably 0.5 to 1.5 g / L.

[0307] Advantageously, high values ​​of [API] allow for a reduction in the particle size required to be effective against the API's target (eg, a tumor).

[0308] Method for preparing nanoparticles

[0309] The copolymers according to the present invention can spontaneously self-assemble into nanoparticles in aqueous solution, said nanoparticles exhibiting a corona formed by pSar blocks and a core formed by pAA blocks.

[0310] The present invention relates to a method for preparing nanoparticles comprising a linear copolymer as described above. Preferably, the nanoparticles are obtained by a method comprising the following steps:

[0311] - preparing an organic solution containing an organic solvent and the linear copolymer of the present invention,

[0312] -The organic solution is then mixed with the aqueous solution,

[0313] -The organic solvent is then removed.

[0314] The organic solvent is preferably a polar aprotic solvent.

[0315] The present invention also relates to a method for preparing nanoparticles, wherein the nanoparticles comprise a linear copolymer and an active compound, wherein the copolymer and the active compound are as described above.

[0316] In the following, the method of preparing nanoparticles is described for a hydrophobic API, but the method is also applicable to any hydrophobic compound as described above.

[0317] Advantageously, if the formation of the nanoparticles is performed in the presence of a hydrophobic API, it allows encapsulation of said API in the hydrophobic core of the nanoparticles.

[0318] The encapsulation of the hydrophobic API by the nanoparticles can be produced by a method comprising the following steps:

[0319] - preparing an organic solution containing an organic solvent, a copolymer as described above and at least one hydrophobic API as described above,

[0320] - mixing the organic solution with the aqueous solution,

[0321] - optionally removing the organic solvent,

[0322] - Recycling of nanoparticles.

[0323] A preferred method for preparing nanoparticles comprises:

[0324] - step i): mixing a hydrophobic API and a copolymer according to the invention in an organic solvent to obtain an organic solution,

[0325] - step ii): mixing the solution obtained in step i) with an aqueous solution under stirring to obtain nanoparticles,

[0326] - optional step iii): filtering the nanoparticles,

[0327] - optional step iv): purification, for example by gel filtration chromatography,

[0328] - optional step v): filtering the nanoparticles,

[0329] - optional step vi): freezing or freeze-drying,

[0330] - Step vii): Recovering the nanoparticles.

[0331] In one embodiment, step ii) is performed by adding the organic solution obtained in step i) to the aqueous solution. In another embodiment, step ii) is performed by adding the aqueous solution to the solution obtained in step i).

[0332] Preferably, the organic solvent is a polar aprotic solvent. Preferably, the polar aprotic solvent is selected from N,N-dimethylformamide and N,N-dimethylacetamide.

[0333] In a preferred embodiment, the solvent used in step ii) is the same as the solvent used in step a) and / or c) of preparing the copolymer. This embodiment facilitates the purification of the copolymer and limits the potential impact of residual solvent from the copolymer preparation on the self-assembly into nanoparticles. Preferably, the solvent is N,N-dimethylformamide.

[0334] Preferably, the aqueous solution is water or comprises water as the main solvent.

[0335] In a preferred embodiment where the nanoparticles are suitable as a pharmaceutical dosage form, the aqueous solution of step ii) may further comprise a cryoprotectant and / or a buffer.

[0336] Cryoprotectants prevent other compounds from damage or changes associated with freezing or freeze drying, and allow physiological osmotic pressure to be achieved. Cryoprotectants include, but are not limited to, monosaccharides, disaccharides, polyols, amino acids, glycine, polyvinyl pyrrolidine, polyethylene glycol, mannitol, sorbitol, sucrose, glucose, raffinose, sucralose, lactose, trehalose, dextran and dextrose. Preferably, the cryoprotectant is trehalose.

[0337] Buffers allow physiological pH to be achieved and also have an effect on osmotic pressure. Buffers include, but are not limited to: phosphate buffer, phosphate buffered saline (PBS), histidine buffer or HEPES buffer.

[0338] Advantageously, the mixing conditions in step ii) are adjusted to optimize the resulting nanoparticles. Such conditions are for example the nature of the mixing (magnetic stirring, homogenizer), the mixing time, the order in which one solution is added to another or the flow rate of addition.

[0339] Optional step iii) may be performed to remove unloaded (free) API from the suspension in order to initiate the purification process and maintain the useful life of the column used in optional step iv).

[0340] The optional step iv) may be performed to obtain a suspension of nanoparticles in aqueous solution by removing the polar protic solvent and the unloaded API. When the aqueous solution is water, then step iv) allows obtaining a suspension of nanoparticles in pure aqueous solution.

[0341] Preferably, the nanoparticles are sterilized by filtering with a 0.2 μm, 0.22 μm or 0.45 μm sterile filter in step v).

[0342] Advantageously, the nanoparticles according to the invention have a loading efficiency LE of greater than 20%, preferably greater than 30%, preferably greater than 40%, preferably greater than 45%, preferably greater than 50%, preferably greater than 55%, preferably greater than 60%, preferably greater than 65%, more preferably greater than 70%. Advantageously, the loading efficiency is between 40% and 99%, preferably between 50% and 96%, preferably between 60% and 95%, more preferably between 70% and 94%.

[0343] The loading efficiency is the weight ratio of the mass of API loaded into the nanoparticles to the mass of feed API.

[0344] Advantageously, the feed weight ratio FWR ranges from 1% to 100%, preferably from 2% to 80%, preferably from 3% to 60%, preferably from 4% to 50%, preferably from 5% to 40%, more preferably from 10% to 30%. FWR is the weight ratio of the mass of feed API to the mass of feed copolymer.

[0345] Example

[0346] In order to better understand the disclosure described herein, the following examples are provided. It should be understood that these examples are for illustrative purposes only and should not be construed as limiting the disclosure in any way.

[0347] In the following examples, the copolymers according to the invention comprise blocks of poly(sarcosine) and blocks derived from γ-benzyl-L-glutamate and / or γ-benzyl-D-glutamate.

[0348] Materials and methods

[0349] Paclitaxel was supplied by Key Organics. All organic solvents (HPLC grade) were supplied by VWR. Water was ultrapure grade. Temperatures were room temperature (22° C. to 28° C.) unless otherwise stated.

[0350] FTIR spectroscopy

[0351] NCA polymerization was monitored by Fourier transform infrared (FTIR) spectroscopy on a Thermo Scientific Nicolet iS5 spectrometer equipped with an ID7 ATR module. Data were processed using OMNIC 9.7 software. -1 The polymerization was stopped when the NCA-related carbonyl band at 40° disappeared, which corresponds to the complete consumption of NCA.

[0352] Proton NMR

[0353] Proton NMR was performed on an 80 MHz MAGRITEK Spinsolve 80Carbon ( 1 H NMR) with the following parameters: Ns=64, repetition time=10 to 30 seconds, pulse angle=90, product dissolved in deuterated dimethyl sulfoxide (d6-DMSO) at a concentration between 20 and 50 g / L. Data were processed using SpinSolve and MestReNova software.

[0354] SEC

[0355] Size exclusion chromatography (SEC) analysis was performed on an Agilent 1260LC equipped with a diode array detector (UV-Vis) and a differential refractive index detector (dRI) and a set of three columns of PSS GRAM analytical columns ( 8x 300mm, 10μm; 8x 300mm, 10μm; 8x300mm, 10μm), with an exclusion limit of 100 to 1000000 g / mol. Samples prepared in DMF containing 0.45% w / v LiBr were analyzed at 45°C using DMF containing 0.45% w / v LiBr as eluent (1 mL / min). Data were collected and processed using OpenLABChemstation software.

[0356] SEC for Characterization of Copolymers

[0357] In order to determine the number average molar mass (M n ) and dispersion The polymer samples prepared at 4 g / L were analyzed. The EasiVial kit for polystyrene from Agilent was used as standard (266 to 66000 g / mol). The data were processed using the Cirrus plugin.

[0358] SEC for characterization of nanoparticles

[0359] To determine the copolymer concentration ([C in NP]) in PTX-loaded nanoparticles, a volume of 400 μL of each NP sample was dried using a centrifugal evaporator (SP Genevac EZ2, water evaporation automatic program). The samples injected into the SEC were prepared by dissolving the dried samples in 1 mL of DMF containing 0.45% w / v LiBr, thus diluting 2.5 times.

[0360] A standard curve for each copolymer was prepared in DMF containing 0.45% w / v LiBr, with polymer concentration ([C]) ranging from 1 to 4 g / L. A linear regression of the area obtained for the polymer's RI signal versus [C] was plotted for each polymer to obtain the standard curve equation.

[0361] For each prepared sample, determine [C in NP] using the peak area obtained and the appropriate standard curve equation, then multiply by the dilution factor.

[0362] The loading content (LC) of PTX-loaded NPs was calculated as the ratio of the mass of PTX recovered at the final stage of NP preparation (m(PTX in NP), obtained by UPLC) divided by the mass of NP; the mass of NP is the sum of the mass of the copolymer (obtained by SEC using [C in NP]) and m(PTX in NP).

[0363] DLS

[0364] DLS measurements were performed on a Zetasizer Pro (Malvern Panalytical) equipped with a He-Ne laser (633 nm) at 25 °C and a scattering angle of 174.8 °. The software used was ZS Explorer. 70 μL of sample was filled into a low-volume plastic cell with a 10 mm optical path length. The viscosity of the dispersant was corrected for the solvent or solvent mixture used. The data were collected in three different measurements by automatically optimizing the number of runs and duration for each measurement. The results are expressed as the average of these 3 measurements. The D h is the mean intensity of each group. PDI is calculated from the autocorrelation function using the cumulant method.

[0365] UPLC

[0366] Ultra-performance liquid chromatography (UPLC) measurements were performed on an Acquity UPLC H-class from Waters equipped with a reversed-phase column (Acquity BEH, C18, 50 mm x 2.1 mm x 1.7 μm, Waters) and a diode array detector (DAD) Acquity eλ from Waters. Data were acquired and processed using Empower 3 software. Gradient elution was performed with the following 2 solvents: solvent A was water containing 0.05 vol% trifluoroacetic acid (TFA), and solvent B was acetonitrile (ACN) containing 0.05 vol% TFA. The column was equilibrated in an 80:20 A:B mixture for at least 30 min. The sequence duration was 8 min, and the gradient of A:B solvents was as follows: 0–3 min 80:20, 3–5 min 5:95, 5–8 min 80:20. The eluent was machine degassed. The flow rate was 0.5 mL / min. The column temperature was 35 °C. The volume injected was 3 μL. The Uv detector was set at 254 nm. The typical retention time of PTX was 2.24 min.

[0367] The loading efficiency (LE) of PTX loaded NPs was determined by UPLC.The injected sample was prepared by dissolving 90 μL of NPs in 910 μL of ACN:DMF 90 / 10 v / v, thus diluting 11.1 times.

[0368] A standard curve was prepared in ACN:(H2O / DMF 90 / 10) 90:10 v / v with PTX concentrations ([PTX]) between 5 and 20 μg / mL. A linear regression of the area at 254 nm versus [PTX] was plotted to obtain the standard curve equation.

[0369] For each formulated sample, the PTX concentration in the nanoparticles ([PTX in NP]) was determined using the obtained peak area and the standard curve equation and then multiplied by the dilution factor.

[0370] LE was calculated as the ratio of m(PTX in NPs) (obtained using [PTX in NPs]) divided by the mass of PTX initially fed into the NP preparation.

[0371] HS-GC

[0372] Use headspace gas chromatography (HS-GC) to measure the content of DMF as residual solvent in preparation.Carry out HS-GC on Agilent7890B GC system, described system is equipped with split / non-split syringe, flame ionization detector (FID), Agilent 7697A automatic sampler, and use CP Sil 5CB post (length is 50m, diameter is 0.32mm, and film thickness is 5 μm).The sample of known quantity is introduced in 20mL pressure-capped vial (crimp vial) and dissolved with several milliliters of low volatility solvent (water, DMSO or NMP).By bottle pressure capping and hatching, to reach the balance of the concentration of residual solvent between liquid phase and gas phase.Then by split syringe, the headspace of bottle is injected in GC system, and residual solvent is detected by FID.OpenLAB Chemstation software is used to collect and process data.

[0373] abbreviation

[0374] The following abbreviations are used in the examples:

[0375] [C] Copolymer concentration

[0376] [C in NP] Copolymer concentration in the nanoparticle

[0377] [PTX] PTX concentration

[0378] [PTX in NP] PTX concentration in nanoparticles

[0379] 1 H NMR Proton nuclear magnetic resonance

[0380] Dispersibility

[0381] D-GluOBzl γ-Benzyl-D-glutamate

[0382] D h Hydrodynamic diameter

[0383] DLS Dynamic Light Scattering

[0384] DMAP dimethylaminopyridine

[0385] DMF N,N-Dimethylformamide

[0386] DMSO Dimethyl sulfoxide

[0387] eq equivalent

[0388] f(pSar) hydrophilicity (polysarcosine) fraction

[0389] FTIR Fourier Transform Infrared

[0390] FWR Feed Weight Ratio

[0391] HS-GC Headspace Gas Chromatography

[0392] LC loading content

[0393] LE Load Efficiency

[0394] L-GluOBzl γ-Benzyl-L-glutamate

[0395] M n Number average molar mass

[0396] MTBE Methyl tert-butyl ether

[0397] NCA N-Carboxylic Anhydride

[0398] NMM N-Methylmorpholine

[0399] NP Nanoparticles

[0400] PDI Polydispersity Index

[0401] PES Polyethersulfone

[0402] pSar polysarcosine

[0403] PTX Paclitaxel

[0404] Sar Sarcosine

[0405] SEC Size Exclusion Chromatography

[0406] TMS Tetramethylsilane

[0407] UPLC Ultra High Performance Liquid Chromatography In the following examples, according to the method described above,

[0408] -pass 1 H NMR determined the values ​​of x, y+z, and f(pSar) for each copolymer;

[0409] - Determine M through SEC n and

[0410] - Determine D by DLS h and PDI;

[0411] - Determination of [PTX] and LE by UPLC;

[0412] - LC determination by SEC.

[0413] Example 1: Preparation of PSAR Block

[0414] Sar NCA (4.34.10 -2 mol, 75 eq) was dissolved in dry DMF, and then neopentylamine was added as an initiator (73 μL, 6.20.10 -4 The reaction mixture was stirred at room temperature and after the CO2 evolution was complete, the completion of the reaction was confirmed by FTIR spectroscopy.

[0415] Precipitation of the polymer was carried out at room temperature by pouring the reaction mixture into 300 mL of ethyl acetate under vigorous stirring. After filtration, the product was reslurried with 2 x 100 mL of ethyl acetate and then dried under vacuum.

[0416] The pSar block S1 with x=75 was obtained with a yield of 70%, M n is 4570 g / mol, is 1.16.

[0417] In addition to using 28eq of Sar NCA (1.62.10 -2 pSar block S2 with x=29 was obtained with a yield of 85%, M n is 2200 g / mol, is 1.22.

[0418] Example 2: Preparation of copolymer of formula I

[0419] Two-step synthesis procedure

[0420] The pSar block S1 (M n =4570 g / mol, 1.31.10 -4 mol, 1.0 eq) was dissolved in dry DMF (17 mL). L-GluOBzl NCA (6.42.10 -3 mol, 49eq) powder and D-GluOBzl NCA (6.42.10 -3 mol, 49eq) powder mixture was added to the reaction medium. The reaction mixture was stirred at 5°C and after the CO2 evolution was complete, the completion of the reaction was confirmed by FTIR spectroscopy.

[0421] The copolymer was precipitated at room temperature by pouring the reaction mixture into 200 mL of MTBE under vigorous stirring. After filtration, the product was reslurried with 2 x 100 mL of MTBE and then dried under vacuum. Copolymer 1 was obtained with a yield of 76%.

[0422] Copolymers C2 to C5 according to the invention were prepared following the same procedure as C1 using the pSar blocks and amounts shown in Table 1.

[0423] Table 1: Preparation conditions of copolymers C2 to C5.

[0424]

[0425] The copolymers C1 to C5 according to the invention have the properties shown in Table 2.

[0426] Table 2: Properties of copolymers C1 to C5 according to the invention.

[0427]

[0428]

[0429] Procedure for one-pot synthesis

[0430] Sar NCA (2.78.10 -2 mol, 70eq) was dissolved in dry DMF, and then neopentylamine (1eq) was added as an initiator. The reaction was stirred at room temperature, and after the CO2 evolution was complete, the completion of the reaction was confirmed by FTIR spectroscopy.

[0431] To the reaction medium containing pSar was added pre-weighed and mixed L-GluOBzl NCA (4.52.10 -3 mol, 12 eq) and D-GluOBzl NCA (4.52.10 -3 After 20 hours at room temperature, complete consumption of NCA was confirmed by FTIR spectroscopy.

[0432] The copolymer was precipitated at room temperature by pouring the reaction mixture into 300 mL of MTBE under vigorous stirring. After filtration, the product was reslurried with 2 x 100 mL of MTBE and then dried under vacuum. Copolymer 6 was obtained with a yield of 54%.

[0433] The properties of copolymer C6 are presented in Table 3.

[0434] Table 3: Properties of copolymer C6 according to the invention.

[0435]

[0436] Example 3: Preparation of copolymer of formula II

[0437] Procedure for the "reverse one-pot" synthesis

[0438] L-GluOBzl NCA (11 eq) and D-GluOBzl (11 eq) were dissolved in 40 mL of dry DMF at room temperature, and then neopentylamine was added as an initiator (58.5 μL, 1 eq). The reaction mixture was stirred at room temperature, and after the CO2 evolution was complete, the completion of the reaction was confirmed by FTIR spectroscopy.

[0439] Sar NCA (70eq) was then added to the reaction mixture. Again, the reaction mixture was stirred at room temperature, and after CO2 release ended, the completion of the reaction was confirmed by FTIR spectroscopy. By pouring the reaction mixture into 200mL of MTBE under vigorous stirring, the copolymer was separated out at room temperature. After filtering, the product was re-slurried with 2x 100mL of MTBE, then dried under vacuum. A copolymer C7 with a yield of 89% was obtained.

[0440] Copolymer C8 was prepared by the same procedure as C7, using L-GluOBzl NCA (24 eq) but without D-GluOBzl NCA. Copolymer C8 was obtained with a yield of 91%.

[0441] Copolymer C9 was prepared by the same procedure as C7, using D-GluOBzl NCA (24 eq) but without L-GluOBzl NCA. Copolymer C9 was obtained with a yield of 85%.

[0442] The properties of copolymers C7 to C9 are presented in Table 4.

[0443] Table 4: Properties of copolymers C7 to C9 according to the invention.

[0444]

[0445]

[0446] End-capping procedure

[0447] Copolymer C8 was dissolved in 10 mL of dry DMF at room temperature, and then DMAP (16 mg, 1.3.10-4 mol, 1 eq) and NMM (162 μL, 1.43.10 -3 After complete dissolution, acetic anhydride (123 μL, 1.3.10 - 3 mol, 10eq), and the reaction mixture was stirred at room temperature overnight.

[0448] The copolymer C10 was precipitated at room temperature by pouring the reaction mixture into 50 mL of MTBE under vigorous stirring. After filtration, the product was re-slurried with 2 x 10 mL of MTBE and then dried under vacuum. Copolymer C10 was obtained with a yield of 83%.

[0449] Copolymer C11 was prepared by the same procedure as C10 using C7 as the starting material. Copolymer C11 was obtained with a yield of 87%.

[0450] Copolymer C12 was prepared by the same procedure as C10 using C9 as the starting material. Copolymer C12 was obtained with a yield of 81%.

[0451] The properties of copolymers C10 to C12 are presented in Table 5.

[0452] Table 5: Properties of copolymers C10 to C12 according to the invention.

[0453]

[0454] Example 4: Preparation of Paclitaxel-Loaded Nanoparticles

[0455] Nanoparticles loaded with paclitaxel (PTX) were formed by a solvent displacement method (also known as nanoprecipitation method).

[0456] Solution 1 was prepared with copolymers C1 to C12 in DMF at a concentration of 200 g / L. Solution 2 was prepared with PTX in DMF at a concentration of 20 g / L. Using solutions 1 and 2, solution 3 was prepared with a feed weight ratio (FWR) of 10%, which contained [C] = 100 g / L and [PTX] = 10 g / L in DMF.

[0457] Using a syringe pump (Fusion 100-X, Chemyx), 1 mL of solution 3 was injected into 9 mL of water at a flow rate of 30 mL / min under stirring at 400 rpm. After complete addition, stirring was performed for 5 minutes.

[0458] The freshly obtained suspension was purified to remove DMF and unloaded drug by first filtering on a 0.20 μm PES syringe filter, then filtering through a gel filtration column (PD-10 desalting, Cytiva) using water as the eluent, and finally filtering on a 0.20 μm PES syringe filter. The resulting NP1 to NP12 nanoparticles had the properties detailed in Table 6.

[0459] Table 6: Characteristics of PTX-loaded nanoparticles NP1 to NP12 according to the invention.

[0460]

[0461]

[0462] / : Undetermined

[0463] nd: not detected (below the detection limit)

[0464] The solubility of PTX in water is lower than 0.1 μg / mL. The results in Table 6 show that the nanoparticles according to the present invention can significantly improve the water solubility of PTX.

[0465] Advantageously, the nanoparticles according to the invention have only trace amounts of DMF present, which is compatible with their use in pharmaceutical applications.

Claims

1. A linear copolymer comprising a polysarcosine block pSar containing 15 to 99 sarcosine constituent units and a poly(amino acid) block pAA containing 8 to 120 amino acid constituent units.

2. The linear copolymer according to claim 1, having a hydrophilicity fraction f(pSar) ranging from 5% to 80%, preferably from 10% to 70%, wherein f(pSar) is the ratio of the number average molar mass of the pSar block to the number average molar mass of the copolymer as a percentage.

3. The linear copolymer according to any one of claims 1 or 2, wherein The pAA block has a hydrophobicity coefficient H equal to or higher than -0.50, preferably equal to or higher than -0.25, preferably equal to or higher than 0.00, preferably equal to or higher than 0.50, more preferably equal to or higher than 0.

80.

4. The linear copolymer according to any one of claims 1 to 3, wherein The amino acid constituent units of the pAA block are hydrophobic amino acids, preferably selected from alanine, valine, norleucine, leucine, isoleucine, methionine, phenylalanine, tryptophan, proline, tyrosine, their derivatives, protected hydrophilic amino acids and combinations thereof.

5. The linear copolymer according to any one of claims 1 to 4, which is a linear copolymer of formula I or II: in x is the number of sarcosine constituent units, and is an integer ranging from 15 to 99, y+z is the number of amino acid constituent units, and is an integer in the range of 8 to 120, Group R y and R z are independently selected from amino acid side chain groups, Group R 1a and R 1b are independently selected from H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl and heteroaryl, Group R 2 is selected from H and a nitrogen protecting group.

6. The linear copolymer according to claim 5, wherein x is an integer in the range of 20-95, preferably 24-85.

7. The linear copolymer according to any one of claims 5 or 6, wherein y+z is an integer in the range of 8-110, preferably 12-100.

8. The linear copolymer according to any one of claims 5 to 7, wherein y+z is an integer in the range of 8-50, preferably 9-45, preferably 12-40.

9. The linear copolymer according to any one of claims 5 to 7, wherein y+z is an integer in the range of 55-110, preferably 60-100.

10. The linear copolymer according to any one of claims 6 to 9, wherein R y and R z Side chains independently selected from L-leucine, L-phenylalanine, L-tyrosine, γ-benzyl-L-glutamate, γ-tert-butyl-L-glutamate, L-cyclohexylglycine, D-leucine, D-phenylalanine, D-cyclohexylglycine, D-tyrosine, γ-benzyl-D-glutamate, and γ-tert-butyl-D-glutamate.

11. A method for preparing a linear copolymer according to any one of claims 1 to 10 by polymerization of a sarcosine derivative and an amino acid derivative, wherein: The derivatives are represented by the following formula III and IV in A is O or S, R y , R z As defined in any one of claims 5 to 10.

12. Nanoparticles comprising the linear copolymer according to any one of claims 1 to 10 or the linear copolymer prepared by the method of claim 11.

13. Nanoparticles according to claim 12, further comprising at least one active compound, preferably selected from hydrophobic active pharmaceutical ingredients.

14. The nanoparticle according to any one of claims 12 or 13, which satisfies at least one of the following conditions: - a hydrodynamic diameter below 400 nm, preferably in the range of 5 to 200 nm; - a polydispersity index lower than 0.70, preferably in the range of 0.02 to 0.70; The loading efficiency of the active compound is greater than 20%, preferably greater than 30%.

15. A method for preparing the nanoparticles according to any one of claims 12 to 14, comprising the following steps: - preparing an organic solution containing the copolymer according to any one of claims 1 to 10, - the organic solution is then mixed with the aqueous solution under stirring, -The organic solvent is then removed.

16. The method for preparing nanoparticles according to claim 15, wherein: The nanoparticles further comprise an active compound, and the method comprises the following steps: - preparing an organic solution containing the copolymer according to any one of claims 1 to 10 and at least one active compound, - the organic solution is then mixed with the aqueous solution under stirring, - The organic solvent is then removed.

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