Poly(ethylene glycol)s having C1 to C3 alkyloxymethyl side chains, bioconjugates thereof, processes for their preparation, and uses thereof

Abstract

The present invention relates to a polyether polymer represented by the following formula [I]: -(CH2CHR-O-)m - [I], wherein 10 to 90% of the residues R are hydrogen, 10% to 90% of the residues R are selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl, 1 to 100% of the residues R are methoxymethyl, up to 50% of the residues R may be selected from the group consisting of ethoxymethyl, n-propoxymethyl, and isopropoxymethyl, m is in the range of 10 to 1000, and the dispersity is less than or equal to 1.15. The present invention further relates to processes for their preparation, to their conjugates, and to their use.

Description

[Technical field]

[0001] The present invention relates to a polyether polymer represented by the following formula [I]: -(CH2CHR-O-) m - [I] wherein 10 to 90% of the residues R are hydrogen, 10% to 90% of the residues R are selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; 1 to 100% of the residues R are methoxymethyl; up to 50% of the residues R can be selected from the group consisting of ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; m is in the range of 10 to 1000, with a dispersity of less than or equal to 1.15.

[0002] The invention further relates to processes for their preparation, to their conjugates, and to their uses. [Background technology]

[0003] Poly(ethylene glycol) (PEG), an aliphatic polyether, is the most widely used polymer in pharmaceuticals, medicine, and drug delivery. PEGylation, the attachment of PEG to peptide drugs, was introduced in the 1970s and has since led to a number of highly efficient drugs. PEGylation is a form of conjugation, i.e., the attachment of a polymer to a molecule by a covalent bond. The main effect of the attachment of PEG chains is the so-called "stealth effect," which prevents close approach and recognition by the immune system and subsequent binding and removal by the reticuloendothelial system (RES) in the liver. More simply, when attached to the surface of drug delivery nanocarriers, PEG attachment also prevents opsonization by proteins. The inhibition of protein adsorption by PEG is further accentuated by the realization of the rules for protein-repellent surfaces derived by Whitesides (Non-Patent Document 1). PEGylation is also used for "stealth liposomes", low molecular weight drugs, and lipid nanoparticles with long circulation times. Such structures are used for transport and delivery of mRNA, where PEG-based lipids play a key role in vaccination against the COVID-19 pandemic, enabling the transport of mRNA to cells and avoiding unwanted degradation processes. The recently approved mRNA vaccines from Moderna Inc. and Pfizer Inc.-BioNTech SE require PEGylated lipids to ensure the stability of mRNA in lipid-based nanoparticles. PEGylation also prevents the coalescence of liposomes and similar structures in aqueous systems. Usually, molecular weights in the range of 2 to 40 kg / mol are preferred for PEGylation of drugs or nanocarriers. In total, PEG has become the standard for water-soluble medical polymers for a huge variety of medical and pharmaceutical uses, particularly in the treatment of cancer, chronic diseases, and recently also for RNA delivery vehicles. The success of PEG may have several reasons, among which are its commercial availability in a wide range of sufficient quality and molar mass from the anionic ring-opening polymerization of ethylene oxide, as well as its extremely low toxicity and high biocompatibility. Furthermore, PEG can be prepared with a narrow molecular weight distribution.

[0004] However, a growing number of studies summarize concerns regarding the presence of so-called anti-PEG antibodies (APA) in a large and ever-increasing part of the population. Such antibodies can lead to accelerated clearance of PEGylated drugs from the bloodstream, i.e. loss of the stealth effect that is essential for therapeutic success, allergic reactions, and even potentially fatal anaphylactic shock in extreme and rare cases. This undesirable effect is observed both for PEGylated peptide drugs, PEGylated liposomes, as well as other PEGylated nanocarriers and PEGylated small molecule drugs. Anti-PEG antibodies are also problematic for PEGylated lipids in RNA-carrying lipid nanoparticles, for example in the context of COVID-19 vaccines. PEG antibodies are often mentioned in the context of possible PEG alternatives as a motivation to look for alternatives beyond PEG. As a rough estimate, approximately 10% of the population experiences allergic reactions when treated with PEGylated preparations. More recently, the nature of binding between PEG and anti-PEG antibodies has been studied by Lai et al. (Non-Patent Document 2). They concluded that the binding of PEG is due to the open ring structure of PEG captured by APA. By counting the number of monomer repeats of the PEG polymer interacting with the inner and outer paratopes of Fab, they found that the size of the PEG antigen epitope is ∼700 g / mol, corresponding to 16 monomer subunits. Hence, at least 16 ethylene glycol units are required for binding by APA. Other studies suggest that shorter regular chain segments of PEG and the methoxy end groups of mPEG (α-methoxypoly(ethylene glycol)) structures also play an important role in recognition. Thus, Patent Document 1 discloses a method for the preparation of PEG conjugates based on end group modification of PEG chains. Variations of the end groups of PEG are disclosed, aiming, for example, to minimize the interaction of the methoxy end groups with anti-PEG antibodies. The authors disclose conjugates in which all of the distal polyalkylene glycol termini of the pure conjugates have hydroxyl groups, and which exhibit reduced antigenicity compared to mPEG-protein conjugates.It has been reported that antibodies induced by PEG-OH have similar affinities for both mPEG and PEG-OH, and that antibodies induced by mPEG recognize mPEG more effectively than PEG-OH (Non-Patent Document 3; Non-Patent Document 4). These results were obtained by using competitive ELISA, implying that anti-PEG antibodies induced by PEG-OH-proteins are directed against the PEG backbone (backbone-specific), whereas antibodies induced by mPEG-protein conjugates are methoxy group-specific. It can be concluded that a regular segment of at least 4-5 to 16 regularly-spaced ethylene glycol units is required to achieve recognition and immunogenic reaction by anti-PEG antibodies. Recent clinical work has demonstrated that the presence of antibodies against PEG makes it possible to predict pegaspargase allergic reactions and rechallenge failure, emphasizing the clinical importance of anti-PEG antibodies in the successful treatment of leukemia in this case (Non-Patent Document 5).

[0005] Three strategies have been developed for modifying the PEG structure to counteract the unwanted APA interactions of PEGylated therapeutics. Replacement of the methoxy end groups of mPEG with hydroxyl groups led to a significant decrease in affinity for anti-PEG antibodies, as demonstrated by competitive ELISA tests. However, it is clear that for large-scale commercial applications, the presence of hydroxyl groups at the termini will require protected functional initiators, which complicates existing synthesis protocols. The second recent strategy is disclosed in US Pat. No. 5,399,433 and relies on a PEG-bottlebrush structure, i.e., small PEG structures attached to a poly(hydroxyethyl methacrylate) backbone. The inventors claim that this type of PEG architecture minimizes anti-PEG antigenicity while preserving the desired stealth properties for surface coatings. However, the resulting PEG-grafted copolymers exhibited rather broad and multimodal molecular weight distributions, which represent a major obstacle to their approval for medical use and PEGylation-like bioconjugation with peptides or lipids. Narrow distributions (Mw / Mn<1.15) were only achievable by performing costly and time-consuming preparative size-exclusion chromatography (SEC).

[0006] Another strategy is to exchange PEG for linear polyether polyglycerol to increase the blood circulation time of liposomes and avoid accelerated blood clearance (see Non-Patent Document 6). However, the use of polyglycerol also leads to the introduction of multiple hydroxyl functional groups into the liposomes, which is in contrast to the aforementioned rules of Whitesides and leads to complex non-specific recognition of peptides in the bloodstream. Therefore, targeted use of conjugated drugs or liposomes is not possible with polyglycerol.

[0007] Since PEGylated therapeutics are often used for chronic or in many cases otherwise fatal diseases, such as cancer treatment, repeated doses must be administered over a long period of time in many cases. PEG is a non-biodegradable polymer and must be excreted from the body by the kidneys. In studies of renal filtration of PEGylated drugs, undesirable accumulation of PEG in the kidney and associated pathological changes in the renal system could be demonstrated (see, for example, Non-Patent Document 7). Thus, the tendency of polyethylene to crystallize can lead to deposition in the kidney. Excretion by the kidney also limits the molecular weight of PEG for medical therapeutics to the renal cut-off size, which is approximately 50 to 60 kDa for globular proteins.

[0008] In 2014, the present inventor reported on the copolymerization of ethylene oxide with glycidyl methyl ether (GME) by using a monomer activation method and tetraoctylammonium bromide and trisisobutylaluminum as initiators (see Non-Patent Document 8). A fairly broad molecular weight distribution was obtained (dispersity ranging from 1.21 to 1.5). These are clearly not suitable for medical applications. As discussed at that time, only molecular weights up to 3000 g / mol and high dispersities have been reported for the polymerization of GME by the conventional anionic ring-opening method. Previous studies on the homopolymerization of GME to poly(glycidyl methyl ether) (PGME) generally asserted that the polymerization poses difficulties and that molecular weight control cannot be achieved by the anionic ring-opening polymerization used for medical PEG (Non-Patent Document 9). In all available reports on GME polymerization to date, either phosphazene bases were used as catalysts or aluminum compounds had to be added in the manner of "monomer-activated polymerization". The same applies to the reaction published by Labbe et al. (10), who used monomer-activated ring-opening polymerization for the synthesis of polyglycidyl ethers. This technique suffers from the usual side reactions depicted in Figure 11. Unwanted transfer of hydrides leads to further initiating species, thus limiting the required high end group fidelity. In addition, the occurrence of isopropyl initiation by monomer-activated ring-opening polymerization has also been reported in the literature, e.g., (11) and (12). None of these polymers or copolymers are suitable for medical applications for several reasons: (i) traces of phosphazene base lead to toxicity and cannot be removed; (ii) the dispersity index exceeds 1.1, which is prohibitive for most medical applications; (iii) the end-group fidelity of the polymers derived from the process is insufficient for attachment to peptides, drugs, or lipids by bioconjugation. Thus, neither PGME homopolymers nor copolymers of PGME have been considered for PEGylated applications to date.

[0009] The formation and retention of well-defined polymer end groups (end group fidelity) is a crucial tool for chain extension and all post-polymerization reactions. End group fidelity is also a decisive factor for the use of polymers in bioconjugates for pharmaceutical applications, where biomolecules are connected by end groups. Polymers with low end group fidelity contain a large amount of macromolecules not bound to biomolecules that cannot be removed from the mixture without excessive expense. The conjugates formed do not have the required purity. Thus, although loss of end groups is undesirable, it cannot be completely avoided. End group fidelity varies greatly depending on the reaction conditions of the preparation of the polymer. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent No. 8,129,330 [Patent Document 2] US Patent Application Publication No. 2019 / 0015520 [Non-patent literature]

[0011] [Non-Patent Document 1] Yarovsky et al., "Quantitative design rules for protein-resistant surface coatings using machine learning," Scientific Reports, 2019, Vol. 9, p. 265 [Non-Patent Document 2] Lai et al., "Structure of an anti-PEG antibody reveals an open ring that captures highly flexible PEG polymers," Communications Chemistry, 2020, Vol. 3, p. 124 [Non-Patent Document 3] Sherman et al., "Role of the methoxy group in immune responses to mPEG-protein conjugates," Bioconjugate Chemistry, 2012, vol. 23(3), pp. 485-499 [Non-Patent Document 4] Sherman et al., "Selectivity of binding of PEGs and PEG-like oligomers to anti-PEG antibodies induced by methoxyPEG-proteins," Molecular Immunology, 2014, 57(2), 236-246. [Non-Patent Document 5] Liu et al., "Antibodies Predict Pegasparagase Allergic Reactions and Failure of Rechallenge," Journal of Clinical Oncology, 2019, Vol. 37, p. 2051 [Non-Patent Document 6] Abu Lila et al., "Use of polyglycerol (PG), instead of polyethylene glycol (PEG), prevents induction of the accelerated blood clearance phenomenon against long-circulating liposomes upon repeated administration," International Journal of Pharmaceutics, vol. 456 (2013), pp. 235-242 [Non-Patent Document 7] Bendele, A.; Seely, J.; Richey, C.; Sennello, G.; Shopp, G., "Short Communication: Renal Tubular Vacuolation in Animals Treated with Polyethylene-Glycol-Conjugated Proteins", Toxicological Sciences, 1998, Vol. 42, pp. 152-157. [Non-Patent Document 8] Frey et al., "A Challenging Comonomer Pair: Copolymerization of Ethylene Oxide and Glycidyl Methyl Ether to Thermoresponsive Polyethers," Macromolecules, 2014, Vol. 47, pp. 5492-5500 [Non-Patent Document 9] Frey et al., Biomacromolecules, 2014, Vol. 15, pp. 1935-1954 [Non-Patent Document 10] Macromolecular Symposia, 2007, Vol. 249-250, p. 392-397 [Non-Patent Document 11] Billouard, C.; Carlotti, S.; Desbois, P.; Deffieux, A., “Controlled” High-Speed ​​Anionic Polymerization of Propylene Oxide Initiated by Alkali Metal Alkoxide / Trialkylaluminum Systems”, Macromolecules, 2004, 37(11), 4038-4043. DOI:10.1021 / ma035768t [Non-Patent Document 12] Herzberger, J.; Niederer, K.; Pohlit, H.; Seiwert, J.; Worm, M.; Wurm, FR; Frey, H., "Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation", Chemical reviews, 2016, 116(4), 2170-2243. DOI: 10.1021 / acs.chemrev.5b00441 Summary of the Invention [Problem to be solved by the invention]

[0012] It is an object of the present invention to provide an alternative polymer that can replace PEG in its applications and that can alleviate at least some of the aforementioned disadvantages of PEG. The alternative polymer should be particularly suitable for replacing PEG in pharmaceutical applications. Furthermore, it is an object to provide a polymer with low dispersity. A further object is to provide a polymer with high end group fidelity. It is also desired to provide a process that allows the preparation of such polymers in a simple and commercially feasible manner. The alternative polymer should have low affinity for anti-PEG antibodies (APA). A further goal is to provide a polymer with low immunogenicity. [Means for solving the problem]

[0013] The present invention relates to poly(ethylene glycol)s having C1 to C3 alkyloxymethyl side chains. The present invention relates to polyether polymers represented by the following formula [I]: -(CH2CHR-O-) m - [I] wherein 10 to 90% of the residues R are hydrogen, and 10 to 90% of the residues R are selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; 1 to 100% of the residues R are methoxymethyl; up to 50% of the residues R can be selected from the group consisting of ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; provided that at least one residue R is hydrogen when at least one residue R is selected from the group consisting of ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; m is in the range of 10 to 1000, characterized in that the dispersity measured by size exclusion chromatography in DMF, by calibration with PEG standards, is less than or equal to 1.15. In this specification, the percentage of the residues R is based on the sum of all the residues R, i.e., m. These new polyether polymers are a new type of material that behave very differently than PEG in terms of affinity for anti-PEG antibodies (APA) and have low immunogenicity. They may also have low crystallinity to amorphous structure. However, the polyether polymers of the present invention behave very similarly to PEG in various characteristics that are important for pharmaceutical applications, including water solubility, hydration, cell viability, and biocompatibility.

[0014] The key to the reduced interaction with APA is the use of substituents on the PEG backbone. The increased spatial requirement of the PEG copolymers prevents or precludes specific "lock and key" interactions with anti-PEG antibodies. Besides the conformational impact, the random or statistical distribution of the substituents on the polymer backbone and / or the random or statistical conformational orientation of the substituents further precludes the generation and formation of specific anti-polymer antibodies.

[0015] The key to the similarity of the characteristics of PEG and the polymers of the present invention is the use of alkoxymethyl side chains, which maintains the water solubility and other properties seen in PEG. The repeating unit of the present polymer where R is a methoxymethyl group, i.e. (-CH2-CH(-CH2-OCH3)-O)-, has the same molecular formula C4H8O2 as the two repeating units of PEG (-CH2-CH2-O)2-, and is therefore a structural isomer of the two main chain repeating units of PEG. It contains the same number of atoms and very similar functional groups. This leads to similar properties, especially similar water solubility, which is important for applications in biological systems. The lack of reactive functional groups on the side chains such as hydroxy, amino, etc. reduces undesired interactions with biological systems.

[0016] Ethoxymethyl, n-propoxymethyl and isopropoxymethyl can be used as residues R to further adjust the properties of the polymer, such as its solubility, its interaction with lipids, its properties regarding the passage through biological membranes, etc. However, these residues lead to a reduced water solubility. Such a selection of substituents also leads to deviations from the behavior of PEG with respect to other properties. For this reason, the amount of repeating units with residues selected from the group consisting of ethoxymethyl, n-propoxymethyl and isopropoxymethyl is limited to 50% of all residues R of the polymer of formula (I). Also, in the embodiment of the invention in which at least 10% of the residues R of the polymer are selected from the group consisting of ethoxymethyl, n-propoxymethyl and isopropoxymethyl, at least 10% are hydrogen, more preferably at least 25% are hydrogen. In a further preferred embodiment, up to 20% of the residues R may be selected from the group consisting of ethoxymethyl, n-propoxymethyl and isopropoxymethyl, and even more preferred, only up to 50% of the residues R may be selected from this group. Such residues are not required for some of the uses of the polymers of the invention in pharmaceutical applications. For this reason, the polymers of the invention in which R is selected from the group consisting of hydrogen and methoxymethyl are preferred. Obviously, the ethylene oxide repeat units of the polymers of the invention also lead to properties similar to PEG. This choice therefore provides a polymer whose behavior is closest to PEG.

[0017] Higher homologues of methoxymethyl, i.e. where R is C4 alkoxymethyl and higher, lead to increasingly poor water solubility and other detrimental properties and should therefore generally be avoided. However, they can be used in small amounts when required, preferably in amounts of 10% or less, more preferably 3% or less, most preferably 1% or less, based on the sum of all residues R selected from the group consisting of hydrogen, methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; i.e., m. When the polyether of the present invention contains higher homologues of methoxymethyl, where R is C4 alkoxymethyl or higher, the same conditions for the presence of hydrogen apply in the same preferred amounts. Various other comonomers can also be used, if necessary, in small amounts, i.e., preferably less than 3 wt%, more preferably less than 1 wt%, most preferably less than 0.1 wt%, based on the weight average molecular weight of the polymer of formula [I]. They may be used, for example, to introduce functional groups or side chains onto the polymer, however, polymers of the invention which contain only repeat units of formula (I) will usually be best suited for use in pharmaceutical applications.

[0018] As mentioned before, ethylene oxide repeat units and glycidyl methyl ether repeat units, i.e., R is methoxymethyl, provide polymers with very similar properties. Due to the very similar properties, the ethylene oxide repeat units on the backbone of PEG can be completely replaced by repeat units substituted by methoxymethyl. That is, 100% of the residues R can be selected from methoxymethyl groups, which constitutes a homopolymer of glycidyl methyl ether. However, this is not preferred. When at least some of the residues R are selected to be hydrogen, the properties of the polymer of the present invention are still closer to those of PEG. Furthermore, compared to homopolymers of glycidyl methyl ether, the immunogenicity of copolymers will be reduced, because they are different not only in the orientation of the side groups, but also in the side groups themselves. Therefore, polymers that are copolymers are preferred in the present invention. The greatest difference between the side groups, and therefore the lowest immunogenicity, is provided by polymers in which some of the repeat units have no side groups, ie, R is hydrogen.

[0019] This will ensure lower immunogenicity. Preference is given to 10 to 90% of the residues R being hydrogen and 10 to 90% of the residues R being selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl. Even more preferred is 20 to 80% of the residues R being hydrogen and 20 to 80% of the residues R being selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl. Polymers according to the invention in which about 50% of all ethylene oxide repeating units are replaced by alkyl glycidyl ethers provide the lowest immunogenicity. For this reason, polymers in which 30 to 70% of the residues R are hydrogen and 30 to 70% of the residues R being selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl are preferred, more preferred are 40 to 60%. The polyether polymers of the invention, in which the polyether is a poly(glycidyl methyl ether-co-ethylene oxide) copolymer, i.e. the residues R are selected from the group consisting of hydrogen and methoxymethyl, are particularly useful in pharmaceutical applications. The same preferred ranges apply to the embodiment in which R is selected from the group consisting of hydrogen and methoxymethyl, i.e. the polyether is a poly(glycidyl methyl ether-co-ethylene oxide) copolymer.

[0020] Particularly preferred are polyether polymers of the invention in which 30 to 70% of the residues R are hydrogen, with the remaining residues R being methoxymethyl. These copolymers containing repeating units in which R is hydrogen combine most of the advantageous properties mentioned above. They have low immunogenicity, good water solubility, low crystallinity, and are otherwise very similar to PEG.

[0021] A further aspect of the polymers of the invention is that the degree of crystallinity, i.e. the degree of crystallization, is reduced compared to PEG, while retaining the same properties. Some of the polymers have an amorphous structure depending on the specific composition. Statistical copolymers of EO with GME or other glycidyl ethers can reduce or completely prevent the crystallization of PEG as a system. The degree of crystallization of PEG and the associated melting point (Table 5) play an important role in several pharmaceutical applications, such as suppositories or solid dispersions of drugs. In other applications, such as highly hydrophilic and biocompatible polyurethane soft foams used in wound dressings, among other purposes, crystallization is not desired and a completely amorphous PEG is required. Due to the random incorporation of the side chains, the copolymers of the invention make it possible to obtain a completely amorphous PEG copolymer structure when more than 25% of glycidyl ether monomers are incorporated. This feature is valid for biomaterials based on triblock and multiblock structures, for example combining polyethers with biodegradable polylactide blocks.

[0022] m is in the range of 10 to 1000; m is preferably in the range of 20 to 900, more preferably in the range of 30 to 800. Most preferably, m is in the range of 30 to 700. These ranges correspond to the polymer weights of PEG that are most suitable for medical applications and are used in existing medical applications of PEG. Furthermore, the polymers of the present invention preferably have a molecular weight M, determined by MALDI-TOF-MS, in the range of 500 to 50.000 g / mol, more preferably in the range of 1.000 to 50.000 g / mol, most preferably in the range of 1.000 to 30.000 g / mol. n These ranges apply to all embodiments of the present invention.

[0023] The copolymers of the present invention can be random or statistical copolymers. Such copolymers offer the lowest immunogenicity because they do not provide a blueprint for the immune system for antibodies. They are inherently resistant to immune responses and are therefore preferred embodiments of the present invention. These polymers can be prepared by the process of the present invention discussed below.

[0024] In one embodiment of the present invention, the polymer of the present invention may be a block copolymer, or may have a block-like structure or a tapered or gradient structure. Methods for preparing such polymers are known to those skilled in the art. In such an embodiment, it is preferred that no more than 5% of the polymer's macromolecules contain blocks with more than 15 ethylene oxide repeat units, and more preferably no more than 5% of the polymer's macromolecules contain blocks with more than 8 ethylene oxide repeat units. This reduces immunogenicity.

[0025] As discussed above, the similarity to PEG is an important feature of the polymers of the present invention. This is especially true for the end groups of the polymer. Processing of PEG for use in the pharmaceutical field usually involves modification of the end groups. For this purpose, any end group known to be used for PEG can also be used for the polymer. This includes not only the use of all known end groups for PEG, but also such modifications, including the type and process of modification. If necessary, the polymer can be provided with ethylene oxide repeat units at either or both ends of the polymer, as represented by formulas [Ia] to [Ic], to allow the polymer to function similarly or practically identically to PEG in this respect. These are preferred embodiments of the present invention. -(CH2CH2-O-) a -(CH2CHR-O-) m - [Ia] -(CH2CHR-O-) m -(CH2CH2-O-) a - [Ib] -(CH2CH2-O-) a-(CH2CHR-O-) m -(CH2CH2-O-) a - [I C]

[0026] In these formulas, the subformula -(CH2CHR-O-) m represents the polymers of the invention described herein, where a can be any number, but is preferably a number ranging from 1 to 10, more preferably a number ranging from 1 to 3. The polymers according to formulas [Ia] to [Ic] allow modification of the termini of the polymer, just as PEG is modified in known processes, especially in current industrial processes. This allows for a smooth transition of established processes from PEG to the polymers of the invention. As will be discussed below, such can be prepared without significant additional effort.

[0027] A further embodiment of the present invention is a polyether polymer represented by any of the following formulas [II] and [IIa] through [IIc]: X-(CH2CHR-O-) m -CH2CHR-Y [II] X-(CH2CH2-O-) a -(CH2CHR-O-) m -CH2CHR-Y [IIa] X-(CH2CHR-O-) m -(CH2CH2-O-) a -CH2CH2-Y [IIb] X-(CH2CH2-O-) a -(CH2CHR-O-) m -(CH2CH2-O-) a -CH2CH2-Y [IIc] In the formula, m is 19 to 999, R is as defined in formula [I], a is as defined in any of formulas [Ia] to [Ic], X is an end group derived from the initiator of the reaction and is an α end group (alpha end group), and Y is an ω end group (omega end group).

[0028] X or Y, or both, may be selected from any terminal group known for use in PEG. The same terminal groups may also be provided in the polymers of formulae [Ia] to [Ic].

[0029] X and Y, independently of one another or both, may comprise one or more functional groups selected from the group consisting of acetal (dialkoxy), aldehyde (formyl), amide (carboxamide), azide, carbonate (alkoxycarbonyl)oxy), carboxyl (carboxy), carboxylic anhydride, ester (alkoxycarbonyl), ether, halo, haloformyl (carbonohalidoyl), hemiacetal (alkoxyol), hemiketal (alkoxyol), hydroxy, imide (imido), imine (imino), ketal (dialkoxy), ketone (oil), orthoester (trialkoxy), primary, secondary, and tertiary amino groups, primary, secondary, and tertiary alkoxy groups, sulfhydryl (sulfanyl, HS-), thioether, and combinations thereof. In a preferred embodiment, X or Y may be selected from the group consisting of alkyl, hydrogen, hydroxy, alkoxy, sulfanyl, phthalimide, amide, amine, and combinations thereof. X or Y or both may be of the formula R-CH, where R is linear, branched, or cyclic alkyl or phenyl, and n is equal to 1 to 20. n X or Y or both may be selected from the group consisting of methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, nonoxy, decanoxy, 3-ethyl-butoxy, 2,3-dialkoxypropoxy, and combinations thereof. X or Y or both may also be the alkoxy residue of an alcohol of the formula: [ka] wherein R is hydrogen, or a straight chain, branched, or cyclic alkyl or phenyl. X or Y or both are of the formula: [ka] The alkoxy residue of a secondary alcohol may be selected from any of the following: wherein R and R' are independently hydrogen, or straight-chain, branched, or cyclic alkyl or phenyl, among which secondary alkoxy groups selected from the group consisting of 2-propoxy, 2-butoxy, 2-pentoxy, 3-pentoxy, 2-hexoxy, 3-hexoxy, 2-heptoxy, 3-heptoxy, 4-heptoxy, and cyclohexyloxy are preferred.

[0030] X or Y or both may also be selected from primary alkenyloxy groups, which may be linear, branched, or cyclic. X or Y or both may also be the alkoxy residue of an alcohol of the formula: [ka] In the formula, R is hydrogen, or a linear, branched, or cyclic alkyl or phenyl, among which primary alkenyloxy groups selected from the group consisting of 2-propenoxy (allyloxy), 3-butenoxy, 2-butenoxy, 3-methyl-2-butenoxy, 4-pentenoxy, 3-pentenoxy, 2-pentenoxy, and 3,5-hexadienoxy are preferred.

[0031] X or Y or both may further be selected from secondary alkenyloxy groups, which may be branched or cyclic. X or Y or both may be an alkoxy residue of any of the following formulae: [ka] where R and R' are, independently of each other, hydrogen or straight-chain, branched, or cyclic alkyl or phenyl. The secondary alkenyloxy group can be of the formula 4-pentene-2-oxy, 3-pentene-2-oxy, 5-hexene-2-oxy, 4-hexene-2-oxy, 3-hexene-2-oxy, 4,6-heptadiene-2-oxy, 1,4-pentadiene-3-oxy.

[0032] X or Y or both may further be selected from aryloxy and heteroaryloxy groups. Benzyloxy groups are particularly preferred. X or Y or both may be an aryloxy or benzyloxy residue of an alcohol of any of the following formulae: [ka] wherein R, R", R'", R"", R'"", R'"", and R""" are, independently of each other, hydrogen, or straight chain, branched, or cyclic alkyl or phenyl. X or Y or both are preferably selected from the group consisting of benzyloxy, phenyloxy, and naphthyloxy.

[0033] X or Y or both may be polyfunctional alkoxy groups, i.e., may have multiple ether bonds at the α or ω positions of multiple macromolecules of the polymers of the invention according to formula [II] or [IIa] to [IIc]. Any suitable polyol may be selected accordingly. X or Y or both may be selected in particular from the group consisting of polyethers of carbohydrates, in particular of ribose, polyethers of 1,1,1-trimethylolpropane, polyethers of glycerol, polyethers of sugars or hydrogenated sugars.

[0034] Additionally, Y may be selected from the group consisting of acrylamide, acrylate, aldehyde, alkyne, amine, aminooxy, azide, benzotriazole carbonate, carboxylic acid, chloroformate, cyanuric chloride, dithioester, epoxide, fluorescein, hydrazide, imidazoylformate, iminoester, isocyanate, maleimide, mesylate, methacrylate, NHS ester, nitrobenzoate, nitrophenyl carbonate, succinimidyl active ester, succinimidyl carbonate, N-succinimidyl carbonate, succinimidyl succinate, thiocarbonate, thiol, thiolcarboxylic acid, tosylate, triflate, vinyl sulfone, and xanthate.

[0035] It is particularly preferred that X is selected from the group consisting of hydrogen, alkyl, hydroxy, sulfanyl, C1-C10 alkoxy, C1-C10 thioalkoxy, amino, amino-C1-C10 alkoxy, dibenzylamino-C1-C10 alkoxy, amide, N-heterocyclic carbene, and N-heterocyclic olefin. It is also particularly preferred that Y is selected from the group consisting of hydrogen, hydroxy, alkoxy, -CH2-C(=O)-R, where R is as defined above, -CHO, alkylcarbonyloxy, alkoxycarbonyloxy, amine, alkylamine, carboxamide, azide, halogen, sulfanyl, thioalkoxy, and sulfonate. In addition, in any alkoxy rest defined herein for residue X, the corresponding thioalkoxy residue may be used, i.e., where a sulfur atom is present instead of an oxygen atom.

[0036] The polymer of the present invention is most preferred in which X and / or Y are selected from the group consisting of low molecular weight drugs, nanocarriers, liposomal structures, peptides, polypeptides, glycoproteins, polynucleotides, polysaccharides, lipid structures, liposomes, surfaces, and interfaces, which are directly covalently bonded to the polymer or via a spacer. Nanocarriers that can be used in the present invention are, for example, selected from the group consisting of carbon nanotubes (CNTs), dendrimers, gold nanorods, lipid nanoparticles (nanoparticels), liposomes, micelles, nanocrystals, niosomes, polymeric nanoparticles (PNPs), solid lipid nanoparticles (SLNs), and virus-based nanoparticles (VNPs).

[0037] The polymers of the present invention have a dispersity of 1.15 or less. The dispersity of the present invention was determined using size exclusion chromatography (SEC) in DMF with calibration by PEG standard, as described in more detail in the examples. They are suitable for applications requiring low dispersity, such as pharmaceutical, medical, and biological applications. The dispersity of a polymer is of great importance in pharmaceutical, medical, and biological applications, because polymers of different molecular weights can behave differently in biological systems. They can differ, for example, in water solubility, membrane permeability, crystallinity, and renal clearance. Since uniform behavior of all molecules is desired in medical applications, low dispersity is often required. Thus, the polymers of the present invention having a dispersity of 1.10 or less are most preferred. This applies to all embodiments of the present invention. In most medical and pharmaceutical applications, a dispersity of 1.10 or less is required. The polymers of the present invention having a dispersity of less than 1.08 are most preferred.

[0038] A preferred embodiment of the present invention is a polyether polymer represented by the following formula [II]: X-(CH2CHR-O-) m CH2CHR-Y [II] wherein the residues R are independently selected from the group consisting of hydrogen, methoxymethyl, ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; 1 to 100% of the residues R are methoxymethyl; up to 50% of the residues R may be selected from the group consisting of ethoxymethyl, n-propoxymethyl, and isopropoxymethyl; provided that when at least one residue R is selected from the group consisting of ethoxymethyl, n-propoxymethyl, and isopropoxymethyl, at least one residue R is hydrogen; X is selected from the group consisting of hydrogen, alkyl, hydroxy, sulfanyl, C1-C10 alkoxy, C1-C10 thioalkoxy, amino, amino-C1-C10 alkoxy, dibenzylamino-C1-C10 alkoxy, amide, N-heterocyclic carbene, and N-heterocyclic olefin. X and / or Y are selected from the group consisting of hydrogen, hydroxy, alkoxy, -CH2-C(=O)-R, where R is as defined above, -CHO, alkylcarbonyloxy, alkyoxycarbonyloxy, amine, alkylamine, carboxamide, azide, halogen, sulfanyl, thioalkoxy, N-succinimidyl carbonate, and sulfonate; X and / or Y may also be selected from the group consisting of low molecular weight drugs, nanocarriers, liposomal structures, peptides, polypeptides, glycoproteins, polynucleotides, polysaccharides, lipid structures, liposomes, surfaces, and interfaces, which are directly bound to the polymer by a covalent bond or by a spacer, characterized in that m is in the range of 19 to 999 and the dispersity is less than or equal to 1.15. N-succinimidyl carbonate is particularly preferred.

[0039] Particularly preferred embodiments of the invention are polyether polymers of the invention where X is alkoxy and Y is hydroxy. More preferably, X is a C1-C10 alkoxy group and Y is hydroxy, and even more preferably, X is a C1-C3 linear alkoxy group and Y is hydroxy. These embodiments resemble commercially available PEG derivatives. Most preferably, X is methoxy and Y is OH, which resembles mPEG.

[0040] As discussed with respect to dispersity, uniform behavior of all molecules is preferred for drugs and excipients used in pharmaceutical and medical applications. The end group fidelity of the polymers of the present invention can be determined by MALDI-TOF-MS or 1 It can be determined by known methods, for example by a combination of MALDI-TOF-MS with H-NMR. The polymers of the present invention preferably have an end group fidelity of at least 95%, more preferably at least 98% for the group X. In a further embodiment, the polymers of the present invention preferably have an end group fidelity of at least 95%, more preferably at least 98% for the group Y. Even more preferred are polyether polymers of the present invention, in which the end group fidelity of the polymer is at least 95% for the groups X and Y, most preferably at least 98%. Particularly preferred are polyether polymers of the present invention, in which the end group fidelity of the polymer is at least 95% for the groups X and Y and the dispersity is 1.10 or less, and most preferred are polyether polymers of the present invention, in which the end group fidelity of the polymer is at least 98% for the groups X and Y and the dispersity is 1.10 or less.

[0041] In another embodiment of the present invention, the polyether polymer is a polyether polymer represented by the following formula [II]: X-(CH2CHR-O-) m CH2CHR-Y [II] wherein R has the same meaning as mentioned in the other embodiments of [I] and [II], and wherein X is selected from the groups X mentioned in the other embodiments of [I] and [II] or from the group consisting of hydrogen or X′, wherein X' is selected from the group consisting of: [ka] where R″=H or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl, preferably R" is alkyl, i.e. [ka] or alkenyl, i.e. [ka] or aryl, i.e. [ka] or alkoxymethyl, i.e. [ka] or alkenyloxymethyl, i.e. [ka] or aryloxymethyl, i.e. [ka] or aminomethyl, i.e. [ka] where: p=1, 2, 3, 4, or 5; k=5 to 500, preferably 5 to 250, and most preferably 10 to 200; and [ka] where R″=H or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl, preferably R" is alkyl, i.e. [ka] or alkenyl, i.e. [ka] or aryl, i.e. [ka] or alkoxymethyl, i.e. [ka] or alkenyloxymethyl, i.e. [ka] or aryloxymethyl, i.e. [ka] or aminomethyl, i.e. [ka] where: p=1, 2, 3, 4, or 5; k=5 to 500; preferably 5 to 250, and most preferably 10 to 200; and [ka] where R″=H or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl, preferably R" is alkyl, i.e. [ka] or alkenyl, i.e. [ka] or aryl, i.e. [ka] or alkoxymethyl, i.e. [ka] or alkenyloxymethyl, i.e. [ka] or aryloxymethyl, i.e. [ka] or aminomethyl, i.e. [ka] where: q=3, 4, or 5; k=5 to 500, preferably 5 to 250, and most preferably 10 to 200; and [ka] In the formula, k=5 to 500, preferably 5 to 250, and most preferably 10 to 200; wherein Y is ZW, i.e., composed of the substituents Z and W linked by a covalent bond; During the ceremony, Z is -O-R'-O-; W is -R-CHCH2- (O-CHRCH2-) m -V; wherein V is X or X'; wherein R' is selected from the group consisting of: [ka] During the ceremony, R″=H, or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl, preferably R" is alkyl, i.e. [ka] or alkenyl, i.e. [ka] or aryl, i.e. [ka] or alkoxymethyl, i.e. [ka] or alkenyloxymethyl, i.e. [ka] or aryloxymethyl, i.e. [ka] or aminomethyl, i.e. [ka] where: s=0 to 20, t=0 to 20, Further R' is: [ka]

[0042] In another embodiment, block copolymers of P(EG-co-GME) and poly(L-lactic acid) (PLLA) having -O-CH, -O-Bz, or -OH as functional groups at the ends of the polymer chain are preferred, i.e., diblock polymers MeO-P(EG-co-GME)-b-PLLA-OH, BzO-P(EG-co-GME)-b-PLLA-OH or HO-P(EG-co-GME)-b-PLLA-OH, and HO-P(EG-co-GME)-b-PLLA-OH, as well as triblock polymers such as HO-PLLA-bP(EG-co-GME)-b-PLLA-OH.

[0043] In all embodiments of the invention, m is in the range of 9 to 999, more preferably in the range of 30 to 800. Most preferably, m is in the range of 30 to 700. These ranges correspond to the polymer weights of PEG that are most suitable for medical applications and are used in existing medical applications of PEG. Furthermore, the polymers of the invention preferably have a molecular weight M, determined by MALDI-TOF, in the range of 500 to 50.000 g / mol, more preferably in the range of 1.000 to 50.000 g / mol, most preferably in the range of 1.000 to 30.000 g / mol. n These ranges apply to all embodiments of the present invention.

[0044] The dispersity of all compounds of the invention, as measured by size exclusion chromatography in DMF with calibration to PEG standards, is 1.15 or less. The end group fidelity of the polymer is at least 95% for the X and Y groups, and the dispersity is 1.10 or less. Most preferably, the end group fidelity of the polymer is at least 98% for the X and Y groups, and the dispersity is 1.10 or less.

[0045] As mentioned above, the polymers of the present invention have similar properties to PEG, especially in biological systems. Therefore, the polymers can replace PEG in most of its applications. The polymers of the present invention are especially designed for use in pharmaceutical and medical fields. They can also be used in veterinary medicine and other biological applications with the same benefits. In these fields, the polymers of the present invention can achieve the same functions as PEG, but have reduced immunogenicity and antigenicity. Due to their irregular structure, they do not induce a strong immune response. The polymers of the present invention show a low response, especially to anti-PEG antibodies, as demonstrated by ELISA tests. Conjugates used to mask drugs and other pharmacologic active compounds usually contain PEG in addition to physiologically active compounds or adjuvants. The polymers of the present invention can be used in place of PEG in any such applications. At the same time, the immune response elicited by this polymer would be weak or non-existent, thereby solving one of the main problems of the use of PEG.

[0046] Thus, a further embodiment of the present invention is a conjugate comprising a polyether polymer of any of the preceding claims and a substrate. The conjugate of the present invention may in turn also be referred to as a polyether-conjugated substrate or a polymer-conjugated substrate. In the conjugate of the present invention, the polymer of the present invention is directly or indirectly covalently bound to the substrate. The polymer of the present invention may be bound to the substrate by a spacer constituting an indirect bond. The substrate may be selected from the group consisting of a pharma-ceutically active compound, an adjuvant, a surface, and an interface. The pharma-ceutically active compound is preferably selected from the group consisting of low molecular weight drugs, peptides, polypeptides, proteins, glycoproteins, polynucleotides, and polysaccharides. The adjuvant is preferably a vesicle or carrier, which is preferably used to carry the pharma-ceutically active compound. The adjuvant is preferably selected from the group consisting of a nanocarrier, a liposomal structure, a lipid structure, and a liposome. Nanocarriers that can be used in the present invention are, for example, selected from the group consisting of carbon nanotubes (CNTs), dendrimers, gold nanorods, lipid nanoparticles, liposomes, micelles, nanocrystals, niosomes, polymeric nanoparticles (PNPs), solid lipid nanoparticles (SLNs), and virus-based nanoparticles (VNPs). In further preferred embodiments, the substrate is selected from the group consisting of low molecular weight drugs, nanocarriers, liposomal structures, peptides, polypeptides, proteins, glycoproteins, polynucleotides, polysaccharides, lipid structures, liposomes, surfaces, and interfaces. Also, in these embodiments, the substrate can be directly covalently bonded to the polymer or via a spacer. Particularly preferred is the conjugate of the present invention with bovine serum albumin.

[0047] The polymers of the present invention can be attached to the substrate directly by a covalent bond or by any kind of spacer. Preferably, the hydroxyl residue at the ω-terminus of the polymer of the present invention is used to attach the substrate or spacer to the polymer. This is the most economical because the polymers of the present invention in which X is an inert group and Y is OH can be most easily prepared (see examples). Conjugation of substrates to the OH group at the end of the ω-terminus of PEG is well established. The same process can be used for the polymers of the present invention. However, substrates can also be attached to the α-terminus of the polymer. The polymers of the present invention can also be attached to more than one substrate. This can be done by using the α-terminus and ω-terminus of the polymer, as well as by using functional end groups of the polymer or spacer that can be attached to multiple substrates. This can also be achieved by using comonomers that have functional groups to which the substrate can be attached. The bond between the polymers of the present invention and the substrate can be prepared by any means currently used to attach PEG to substrates. It is also possible to attach multiple macromolecules of the polymer of the invention to one substrate, which is particularly useful for vesicles of all kinds, including liposomes.

[0048] A typical example of a PEG conjugate is the lipid nanoparticles that are essential for the vaccine against Covid-19 from BioNTech SE and Pfizer Inc. and Moderna Inc. The lipid nanoparticles (LNPs) that contain PEG conjugates of lipids are used to encapsulate and protect the pharma- ceutically active substance mRNA. The PEG of these conjugates can be replaced by the polymers of the present invention, thereby retaining the effect of the PEG polymer of the conjugate and at the same time reducing the immune response against the conjugate. A further vaccine of this type is the Covid-19 vaccine from Curevac NV. Further drugs that contain PEG conjugates in which the PEG can be replaced by the polymers are listed below.

[0049] [Table 1A] [Table 1B] [Table 1C]

[0050] In another embodiment of the present invention, the present invention relates to a process for the preparation of polyether polymers by anionic ring-opening copolymerization (AROP) comprising the steps of: - Anion An - To provide - expression [ka] wherein R is as defined as described for either formula [I] or [II]; - allowing the polymerization to proceed at a temperature ranging from -10 to 90°C; The monomer contains less than 1 wt% epichlorohydrin.

[0051] In the process of the present invention, the anion An - must be an anion suitable for anionic ring-opening copolymerization (AROP). Those skilled in the art can easily select from among known anions for this purpose. - The anions are alkyl anions, hydrides, and OH - , alkoxy - , S.H. - , thioalkoxy -The anions may be selected from the group consisting of anions of amine, amide, imide, and combinations thereof. The alkyl and hydride anions may be provided in the form of metal alkyl or metal hydride compounds. The alkoxy and thioalkoxy anions may be corresponding anions having the same structure as any of the alkoxy, aryloxy, and aralkoxy groups defined herein for residue X. However, preferably, the alkoxy and thioalkoxy anions are not tertiary alkoxy anions. The imide anion is preferably a phthalimide anion. The polymers of formula [Ia], [Ic], [IIa], and [IIc] are prepared by first converting a corresponding amount of ethylene oxide into the anion An - and allowing the polymerization to proceed at temperatures ranging from -10 to 90°C until all of the ethylene oxide is consumed. [ka] and allowing the polymerization to proceed at a temperature ranging from -10 to 90°C. In this manner, the repeat units adjacent to the α-terminus of the polymer of the present invention are provided with the exact same structure as PEG. Polymers of formula [Ia], [Ic], [IIa], and [IIc] are of formula X-(CH2CH2-O-) a - where a is as defined for any of formulas [Ia], [Ic], [IIa], and [IIc], and X is any residue defined herein for X. X' is any residue defined herein for X'. This is the preferred method. X is an alkyl, alkoxy, dialkylamine anion, or (RCO)N - Formula X-(CH2CH2-O-) a - Particularly preferred is the use of such an anion MeOCH2CH2O - , MeO(CH2CH2O)2 - , benzyl OCH2CH2O -, BzO(CH2CH2O)2 - , (Bz)2N-CH2CH2O - , (Bz)2N-(CH2CH2O)2 - , phthalimide-CH2CH2O - , phthalimide-(CH2CH2O)2 - Even more preferred is the use of an anion selected from the group consisting of: MeO(CH2CH2O)2, where Me is methyl and Bz is benzyl. - , BzOCH2CH2O - , and (Bz)2N-CH2CH2O - is most preferred.

[0052] In addition, the two hydroxyl-terminated P(EG-co-GME) can be used as a macroinitiator for the ring-opening polymerization of cyclic polyesters, cyclic diesters, or cyclic monoesters, such as L-lactide, D-lactide, meso-lactide, cyclic carbonates, such as trimethylene carbonate (TMC), 2,2-dimethyl-trimethylene carbonate (DTC), 5-butyl-1,3-dioxane-2-one, and 1,3-dioxepan-2-one; glycolide, other cyclic esters, and lactams, N-carboxyanhydrides, to synthesize bifunctionally initiated α,ω-OH-P(EG-co-GME) copolymers, which allow the synthesis of ABA triblock copolymers. In one embodiment of the invention, the reaction is carried out using L-lactide, which allows the synthesis of, for example, PLLA-bP(EG-co-GME)-b-PLLA, where PLLA is [ka] In the formula, k is 5 to 500, preferably 5 to 250, and most preferably 10 to 200.

[0053] The polymerization is catalyzed by Lewis acids such as triethylaluminum (AlEt3) and tin(II) bis-(2-ethylhexanoate) (Sn(Oct)2) or organic bases such as DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) and N-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene. The procedure described is not limited to triblock copolymers. The use of a monofunctional P(EG-co-GME) macroinitiator leads to diblock copolymers (P(EG-co-GME)-b-PLLA).

[0054] In these and other embodiments, An - is alkoxy - , thioalkoxy - and amine anions.

[0055] Furthermore, in the final step of the preparation, a small amount of pure EO can be added to ensure a primary hydroxyl end group at the ω-end of the polymer that can undergo all established coupling strategies to therapeutic drug entities, leading to the polymers of the invention having formulae [Ib], [Ic], [IIb], and [IIc].

[0056] An - The counter ion for the anion is preferably Na + , K + , and Cs + The anion An - may be provided in an inert solvent.

[0057] The anionic ring-opening polymerization of epoxides can be carried out in aprotic solvents such as DMSO or other polar aprotic solvents such as tetrahydrofuran (THF), methyl-THF, cyclopentyl methyl ether (CPME), benzene, toluene, xylene, HMPA, dioxane, diglyme, etc. Surprisingly, it has been found that random copolymers can be synthesized by using the aprotic solvent DMSO and statistical copolymers can be synthesized by using polar aprotic solvents such as toluene. This can be seen from Figures 9, 10, 14, and 15.

[0058] The solvent is preferably an aprotic solvent, most preferably dimethylsulfoxide (DMSO), and the reaction is preferably carried out in the same solvent.

[0059] Anionic ring-opening polymerization with alkyl glycidyl ethers is more prone to undergo chain transfer reactions, as follows: [ka]

[0060] These side reactions increase with temperature. Hence, high molecular weight polymers can only be obtained if the reaction temperature is not above 90°C. Chain transfer reactions result in a broad distribution of molecular weights and therefore a high dispersity. Hence, lower polymerization temperatures also provide the polymers of the invention with lower dispersity. On the other hand, alkyl glycidyl ethers are as reactive as ethylene oxide in anionic ring-opening polymerization. For this reason, the polymerization can be carried out at temperatures as low as -10°C. Preferably, the polymerization is carried out at temperatures ranging from 10 to 70°C, more preferably from 10 to 60°C.

[0061] A further problem with anionic ring-opening polymerization is that commercially available alkyl glycidyl ethers are prepared from epichlorohydrin. A portion of the epichlorohydrin remains in the alkyl glycidyl ether. The presence of the alkyl glycidyl ether leads to termination reactions as follows: [ka]

[0062] This in turn leads to low molecular weight and high dispersity of the product. Thus, the polymers of the present invention are only accessible by reaction temperatures of -10 to 90°C or less and by using alkyl glycidyl ethers containing less than 1 wt% epichlorohydrin. Preferably, the alkyl glycidyl ether contains less than 0.5 wt%, more preferably less than 0.1 wt% epichlorohydrin. Most preferably, the alkyl glycidyl ether is free of epichlorohydrin. Since glycidyl methyl ether and epichlorohydrin have similar boiling points, e.g., 117.9°C for epichlorohydrin and 110°C for glycidyl methyl ether, removal of epichlorohydrin from glycidyl methyl ether to the required extent is not possible. A procedure for the preparation of epichlorohydrin-free alkyl glycidyl ether is provided in Example 1 of the present invention.

[0063] Furthermore, the higher temperature increases the starting anion An - or even lead to side reactions of the X group of the living polymer. Thus, limiting the temperature to the aforementioned range also improves the end group fidelity at the α-terminus of the polymer of the present invention, allowing end group fidelity of 95% or more of the X residues. Other known methods for the polymerization of alkyl glycidyl ethers do not provide the low polydispersity required for the present polymers, nor do they allow the same high end group fidelity.

[0064] To provide the random or statistical copolymers of the present invention, it is necessary to add at least two different types of monomers to the anion. The reactivity ratios of both alkyl glycidyl ethers and ethylene oxide used are in the range of 0.7 to 1.3 or 0.6 to 1.7. For glycidyl methyl ether and ethylene oxide, the reactivity ratio is in the range of 0.98 to 1.02 for polymerization in DMSO. This results in an almost ideally random copolymer. Copolymers of other forms, i.e. block, block-like, or tapered or gradient structures, can be prepared according to known methods. Block copolymers can be easily prepared by subsequent addition of different monomers to a living polymer. Thus, the process of the present invention is preferred in which the step of adding at least one monomer and allowing the polymerization to proceed is repeated at least once, whereby at least one monomer different from the first one is used.

[0065] A further embodiment of the invention is the use of the polyether polymer of the invention for the preparation of a conjugate of the polymer with a substrate. The substrate is as defined herein for the conjugate of the invention. The substrate is preferably a biologically active compound. There is a well-developed chemistry for the preparation of conjugates of PEG, which is known to the skilled person. The same chemistry can be used for the preparation of the conjugate of the invention. The use of the invention for the preparation of conjugated lipids for use in vaccines, in particular based on lipid nanoparticles, is preferred. Such nanoparticles are preferably nanoparticles used against COVID-19. Conjugates of the polymer of the invention with bovine serum albumin (BSA) are preferred. Particularly preferred are conjugates of the polymer of the invention in which the y group of the polymer is an N-succinimidyl carbonate group. Even more preferred are conjugates of the polymer in which bovine serum albumin is conjugated to the polymer of the invention by means of such group Y. Conjugation of α-BzO-ω-N-succinimidyl carbonate-P(EG-co-GME) to bovine serum albumin is most preferred.

[0066] An additional embodiment of the present invention relates to the preparation of the conjugate of the present invention. As discussed above, the conjugate can be prepared by any known process for the preparation of a conjugate of PEG. In addition, the present invention provides a process in which the process for the preparation of the polymer of the present invention is first carried out, and then a substrate is added to the living polymer, the substrate having a functional group that reacts with the living polymer to form a conjugate. [Brief description of the drawings]

[0067] [Figure 1] FIG. 1 shows the results of ELISA testing of three of the polymers of the invention and mPEG. [Diagram 2] ~ [Figure 4] These figures show SEC traces of polymers of the invention synthesized in DMSO, and FIG. 4 additionally shows the SEC trace of commercially available mPEG. [Diagram 5] FIG. 5 shows the 1H-NMR spectrum of α-BzO-P(EG0.51-co-GME0.49). [Figure 6] FIG. 6 shows the MALDI-TOF spectrum of α-BzO-P(EG0.51-co-GME0.49). [Figure 7] FIG. 7 shows the cloud point of α-BzO-P(EG0.51-co-GME0.49). [Figure 8] FIG. 8 shows the MALDI-TOF spectrum of α-MeO-P(PEG0.88-b-PGME0.22), a block copolymer of the present invention. [Figure 9] FIG. 9 shows the decreasing 1H-NMR signal of the monomer during the preparation of the polymer of the invention. [Figure 10] FIG. 10 shows the results of a study of the relative reactivity of ethylene oxide and glycidyl methyl ether in anionic ring-opening polymerization. [Figure 11]Figure 11 shows the mechanism and side reactions of monomer-activated ring-opening polymerization using triisobutylaluminum leading to low end group fidelity, where a) is epoxide activation; b) is "ate" complex formation; c) is initiation and propagation; d) is termination; and e) is side reaction. [Figure 12] FIG. 12 shows the SEC traces of EG-GME copolymers synthesized in toluene at different temperatures. [Figure 13] FIG. 13 shows the MALDI-TOF-MS of BnO-P(EG-co-GME) synthesized in toluene at 25° C. [Figure 14] FIG. 14 shows stacked NMR spectra of the copolymerization of EO and GME in toluene-d8 at different times of copolymerization. [Figure 15] FIG. 15 shows the composition profile based on the resulting reactivity ratios. [Figure 16] FIG. 16 shows the turbidity measurements of P(EG-co-GME) with different mol% of GME at a constant concentration. [Figure 17] FIG. 17 shows the synthesis of P(EG-co-GME) with different end groups. [Figure 18] FIG. 18 shows the SEC traces of EO-GME copolymers with different end groups. [Figure 19] FIG. 19 shows the SEC traces of α,ω-OH-P(EG-co-GME) and two PLLA-bP(EG-co-GME)-b-PLLA. [Figure 20] FIG. 20 shows the 1H-NMR spectrum of PLLA-bP(EG-co-GME)-b-PLLA. [Figure 21] FIG. 21 shows the 1H-NMR-DOSY spectrum of PLLA-bP(EG-co-GME)-b-PLLA. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0068] reagent: Unless otherwise noted, chemicals were purchased from TCI EUROPE NV, Acros Organics BVBA, Carl Roth GmbH, Sigma-Aldrich Co. LLC, and Honeywell Research Chemicals. Ethylene oxide was obtained from Air Liquide SA. Deuterated solvents were purchased from Deutero GmbH. THF was flushed with basic aluminum oxide before use. Glycidyl methyl ether was dried and cryotransferred with CaH2 before polymerization.

[0069] measurement: 1 H and 13 C-NMR spectra were recorded at 300 MHz on a Bruker AvanceIII-HD300 spectrometer and were internally referenced to the residual proton signals of the deuterated solvent. 1 In the case of H-DOSY-NMR, spectra were recorded at 400 MHz on a Bruker AvanceIII-HD400 spectrometer and were internally referenced to the residual proton signals of the deuterated solvent.

[0070] M of all samples w , M n , and the dispersity (M w / M n = PDI) was determined from the corresponding size exclusion chromatogram (Refractive Index (RI) detector, DMF, calibrated with PEG standards).

[0071] Size exclusion chromatography (SEC) measurements were performed on a poly(2-hydroxyethyl methacrylate) (PHEMA) 300 / 100 / 40 column at 50 °C with dimethylformamide (DMF with 1 g / L LiBr) as the mobile phase (flow rate 1 mL / min). The polymer concentration was 1 mg / mL. Calibration was performed using poly(ethylene glycol) standards (from Polymer Standards Service GmbH, Mainz, Germany).

[0072] Differential scanning calorimetry (DSC) measurements were performed on a PerkinElmer DSC8500 at a heating rate of 10 K / min in the temperature range from -100 to 100°C. The temperature history of the samples was eliminated by two cooling and two heating cycles. For each sample, the glass transition and melting temperatures were obtained from the curve of the second heating.

[0073] MALDI-ToF-MS measurements were performed on a Bruker autoflex-maX-MALDI-TOF / TOF. Potassium trifluoroacetic acid and trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile (DCTB) were used as the ionization salt and matrix, respectively.

[0074] Example 1: Synthesis of glycidyl methyl ether (GME) [ka]

[0075] a) Allyl methyl ether (10.0 g, 139 mmol) was dissolved in 274 mL dichloromethane (DCM) and m-chloroperbenzoic acid (m-CPBA, 70%, 37.6 g, 153 mmol (based on m-CPBA)) was added to the solution. After stirring overnight, the solution was filtered and slowly concentrated under reduced pressure. The crude glycidyl methyl ether was separated from solid impurities by cryotransfer. Slow evaporation of the residual dichloromethane in vacuum gave pure glycidyl methyl ether as a colorless liquid; yield 41%.

[0076] b) 1-Chloro-3-methoxy-propan-2-ol (3.00 g, 2.56 mL, 24.1 mmol) and anhydrous sodium sulfate (1.02 g, 7.23 mmol) were added to a flask equipped with a magnetic stirrer and cooled by a water bath. Ground sodium hydroxide (1.25 g, 31.3 mmol) was added under stirring. After complete reaction (TLC control), the crude product was cryo-transferred from the reaction flask under vacuum and dried over CaH2 under cooling. After additional cryo-transfer, GME was obtained as a colorless liquid in 93% yield.

[0077] Example 2: General procedure for the preparation of random copolymers α-BzO-P(EG 0.51 -co-GME 0.49 Synthesis of Ph-CH2-O-CH2-CH2-O-[CH2-CH2-O-] 0.51 -[CH2CH(CH2-O-CH3)-O-] 0.49 H Cesium hydroxide monohydrate (28.0 mg, 118 μmol) was dissolved in a THF-water mixture and transferred to a reaction flask equipped with a Teflon stopcock and septum. 2-Benzyloxy-ethanol (20.0 mg, 18.7 μL, 131 μmol) was dissolved in benzene and added to the reaction flask. After slow evaporation of the solvent, the resulting solid was dried under high vacuum at 60 °C overnight. The residue was dissolved in DMSO (5 mL) and the solution was cooled to -78 °C. GME (367 mg, 374 μL, 4.16 mmol) was added via syringe and EO (183 mg, 189 μL, 4.16 mmol) was cryotransferred from a graduated ampoule to the reaction flask. The solution was stirred under vacuum at room temperature for 48 h. The solution was then poured into excess chloroform and the organic phase was extracted against water (three times) and brine, dried over MgSO4, and filtered. After evaporation of the solvent and drying under high vacuum, P(EG 0.51 -co-GME 0.49 ) was obtained in quantitative yield as a viscous liquid. Product data can be found in Tables 2 and 3, entry e.

[0078] Example 3: Synthesis of mPEG-b-PGME Me-O-[CH2-CH2-O-] 0.78 -[CH2CH(CH2-O-CH3)-O-] 0.22 H Potassium tert-butoxide (13.0 mg, 118 μmol) was dissolved in a tetrahydrofuran (THF)-water mixture and transferred to a reaction flask equipped with a Teflon stopcock and septum. Methoxypoly(ethylene glycol) (mPEG, M nmPEG-b-PGME4k (253 mg, 258 μL, 2.88 mmol) was dissolved in benzene and added to the reaction flask. After slow evaporation, the residue was dried under high vacuum at 80° C. overnight. The residue was dissolved in dimethyl sulfoxide (DMSO, 5 mL) and the solution was cooled to −78° C. Glycidyl methyl ether (253 mg, 258 μL, 2.88 mmol) was cryotransferred to the reaction flask. The solution was heated to 55° C. and stirred under vacuum for 24 h. After that, the solution was poured into excess chloroform and the organic phase was extracted against water (three times) and brine, dried with MgSO4, and filtered. After precipitation with ice-cold diethyl ether, mPEG-b-PGME4k was obtained as a colorless solid; quantitative yield. Tables 2 and 3, entry l, show the data for this polymer.

[0079] Example 4: Synthesis of α-BzO-ω-N-succinimidyl carbonate-P(EG-co-GME) [ka]

[0080] N,N'-disuccinimidyl carbonate (3.5 mg, 13.8 μmol) was added to a stirred solution of α-BzO-P(EG-co-GME) from Example 2 (50.0 mg, 4.6 μmol) in dry CH3CN (1 ml) at room temperature for 18 h. The reaction mixture was dissolved in dichloromethane, extracted with saturated NaHCO3, water, and brine, dried with MgSO4, and filtered. The solvent was removed under reduced pressure and the polymer was dried in vacuum. The product was obtained as a white solid; quantitative yield.

[0081] Example 5: Conjugation of α-BzO-ω-N-succinimidyl carbonate-P(EG-co-GME) to bovine serum albumin (BSA). [ka]

[0082] Bovine serum albumin (5 mg, 0.07 μmol) and α-BzO-ω-N-succinimidyl carbonate-P(EG-co-GME) from Example 4 (16.9 mg, 2.6 μmol) were stirred for 1 h in phosphate buffered saline (PBS buffer). Unreacted polymer was dialyzed off in deionized water through a 25 kDa membrane filter. The conjugate was then dried by lyophilization and obtained in quantitative yield. In the preparation of this conjugate, the outer lysine groups (30-35) were targeted for conjugation.

[0083] Example 6: Competitive enzyme-linked immunosorbent assay (ELISA) The interactions of the copolymer samples with items c, d, and e were assessed by competitive PEG-ELISA kit using a murine monoclonal horseradish peroxidase-conjugated anti-PEG antibody (HRP-anti-PEG) (Life diagnostics Inc., West Chester, PA, USA) ranging from 0 to 4600 μg ml -1 Samples were prepared in dilution buffer at concentrations ranging from 5000 g mol -1 mPEG with a molecular weight of 1000 was used as an internal standard for comparison. 50 μl of each prepared sample was dispensed into a PEG pre-coated 96-well plate, and 50 μl of HRP anti-PEG was added to each well. The solution was incubated on a microplate shaker at 25°C for 1 h, and then washed six times with 400 μl of wash buffer per well. After removal of residual droplets, 100 μl of 3,3',5,5'-tetramethylbiphenyl-4,4'-diamine was added to each well, and the solution was mixed on a microplate shaker for 20 min. The reaction was stopped by the addition of 100 μl of stop solution, and the absorbance at 450 nm was read within 5 min.

[0084] Analysis of ELISA data: The determined absorbance values ​​were normalized to visualize the percentage of maximum binding. Sample concentrations were expressed as log 10The sigmoidal fit was calculated using the following equation: where a is the upper bound, b is the lower bound, c is the inflection point, and d is the Hill slope. y=a+(ba) / 1+10 (c-x)*d

[0085] Example 7: Kinetics of synthesis of α-BzO-P(EG-co-GME) The synthesis of α-BzO-P(EG-co-GME) was carried out online in situ in fully deuterated DMSO. 1 The H-NMR kinetics was repeated. 95 mg glycidyl methyl ether (95 μl, 1.1 μmol) and 32 mg ethylene oxide (33 μl, 7.1 μmol), i.e. 60% glycidyl methyl ether and 40% ethylene oxide, were dissolved in fully deuterated DMSO. The consumption of ethylene oxide and glycidyl methyl ether over time was 1 The concentration of ethylene oxide was measured by H-NMR spectroscopy. As a measure of the ethylene oxide concentration, the signal of the ethylene oxide proton at about 2.6 ppm was used. For glycidyl methyl ether, the signals of the oxirane ring protons, which have absorptions at about 2.75 and 3.1 ppm, were used. Figure 9 shows the selected concentrations of the two monomers over time. 1 The decrease in the H-NMR signal is shown in FIG. x,t / M x,t=0 As can be seen, ethylene oxide and glycidyl methyl ether are consumed at exactly the same rate. This data shows that the copolymers of the present invention are nearly ideal random copolymers.

[0086] Furthermore, 1 H-NMR kinetics was performed to investigate the effect of changing the solvent from DMSO to toluene on the copolymerization kinetics, as can be seen in Figure 14. In addition, based on the decrease in the monomer signal during copolymerization, r EO = 0.61 and r GMEA copolymerization parameter of =1.65 was obtained, indicating a slightly more favorable incorporation of GME repeat units compared to EO at the beginning of the copolymerization due to the higher reactivity of GME compared to EO, leading to a statistical copolymer, as can be seen in Figure 15.

[0087] Example 8: mP(EG according to Figure 17 0.66 -co-GME 0.34 Synthesis of (1) mP(EG 0.66 -co-GME 0.34 ) (1): Diethylene glycol monomethyl ether (50.8 mg, 420 μmol) was dissolved in benzene (5 mL) and transferred to a flame-dried flask under constant vacuum via syringe. Potassium tert-butoxide (42.7 mg, 380 μmol) was dissolved in stabilizer-free THF (3 mL) and a small amount of Millipore water and transferred to the flask. High vacuum was applied to the flask and the solvent was removed under high vacuum. The resulting initiator salt was dried overnight at 60° C. under high vacuum and finally dissolved in dry DMSO (5 mL) under constant vacuum. After freezing the resulting solution at −90° C., GME (1.03 g, 11.6 mmol) was added to the flask via syringe. EO (1.04 g, 1.00 mL, 23.6 mmol) was added to the flask by cryotransfer before removing the cooling bath and allowing the reaction mixture to warm to room temperature. The reaction was allowed to stir at room temperature for 72 h, after which the polymerization was terminated by the addition of a mixture of 2 M HCl (500 μL) and MeOH (500 μL).

[0088] The reaction mixture was added to chloroform (20 mL) and washed three times with Millipore water (10 mL) and once with brine. The organic phase was dried over MgSO4 before the solvent was removed under vacuum. The resulting polymer was dialyzed against MeOH (2 kDa MWCO) for 24 h and freeze-dried overnight under high vacuum to give 1.82 g (86%) of polymer (1) of Figure 17 as a pale yellow viscous liquid. Product data can be found in Tables 2 and 3, entry n.

[0089] Furthermore, α-BzO-P(EG-co-GME) with varying amounts of monomers were prepared following the same procedure with a polymerization temperature of 55°C and benzyloxyethanol as the initiator instead of diethylene glycol monomethyl ether, respectively (entries c and d in Tables 2 and 3).

[0090] Example 9: mP(EG according to Figure 17 0.66 -co-GME 0.34 Synthesis of )-Ms(2) mP(EG 0.66 -co-GME 0.34 )-Ms(2): Polymer (1) (600 mg, 120 μmol) was dissolved in benzene (5 mL) and added to a flame-dried flask under argon flow. Benzene was slowly removed under high vacuum. The polymer was heated to 60° C. and dried under high vacuum overnight. Under argon flow, the dried polymer was dissolved in dry DCM (10 mL) and triethylamine (97.1 mg, 960 μmol) and methanesulfonyl chloride (110 mg, 960 μmol) were added under ice cooling. The mixture was allowed to stir under argon at room temperature for 72 h. Afterwards, the mixture was washed three times with Millipore water and once with brine. The organic phase was dried over MgSO4 and the solvent was removed under high vacuum to give 427 mg (70%) of mesylated polymer (2) as a dark yellow viscous liquid. Product data can be found in Tables 2 and 3, entry o.

[0091] Example 10: mP(EG according to Figure 17 0.66 -co-GME 0.34 Synthesis of )-N3(3) Polymer (2) (400 mg, 80.0 μg) was dissolved in benzene (5 mL) and added to a flame-dried flask under argon flow. Benzene was removed under high vacuum. The polymer was further heated to 60° C. and dried under high vacuum overnight. Afterwards, the dried polymer was dissolved in dry DMF (8 mL) and sodium azide (41.6 mg, 640 μmol) was added as a suspension in dry DMF (2 mL) under argon flow. The reaction mixture was stirred at 65° C. for 72 h. The solvent was removed under high vacuum and the residue was suspended in DCM (10 mL) and treated with an ultrasonic bath for 20 min. The remaining residue was filtered off and the filtrate was washed three times with Millipore water and once with brine. The organic phase was dried over MgSO4 and the solvent was removed to give 284 mg (71%) of polymer (3) as a dark yellow viscous liquid. Product data can be found in Tables 2 and 3, item p.

[0092] Example 11: mP(EG according to Figure 17 0.66 -co-GME 0.34 )-NH2(4) Polymer (3) (180 mg, 40.0 μg) was dissolved in EtOH (10 mL). A catalytic amount of Pd / C 10 wt% (13.8 mg, 10.0 μmol of Pd) was added to the solution and a balloon filled with excess H2 gas was connected to the flask. Vacuum was applied to the flask until the solvent began to evaporate, and the flask was then flushed with argon. This process was repeated two more times. Then, vacuum was applied and the flask was flushed with H2 gas until the solvent began to evaporate. The last step was repeated two more times. The reaction was allowed to stir under 1 atm of H2 gas for 48 h. After 24 h, the H2 balloon was refilled to ensure saturation of the atmosphere with H2. After 48 h, the balloon was removed, the catalyst was filtered off through zeolite, and the solvent was removed under high vacuum to give 142 mg (79%) of amino-terminated polymer (4). Product data can be found in Tables 2 and 3, entry q.

[0093] Example 12: Synthesis of α,ω-OH-P(EG-co-GME) 2,2'-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(ethan-1-ol) (BHEPP) (123 mg, 389 μmol) was dissolved in benzene (5 mL) and transferred via syringe to a flame-dried flask under argon. Potassium tert-butoxide (43.6 mg, 389 μmol) was dissolved in stabilizer-free THF (3 mL) and a small amount of Millipore water and transferred to the flask. High vacuum was applied to the flask and the solvent was removed under high vacuum. The resulting initiator salt was dried overnight at 70° C. under high vacuum and finally dissolved in dry DMSO (5 mL) under constant vacuum. After freezing the resulting solution at −78° C., GME (873 mg, 890 μL, 9.91 mmol) was added to the flask via syringe. EO (1.46 g, 1.50 mL, 33.1 mmol) was added to the flask via cryotransfer before removing the cooling bath and allowing the reaction mixture to warm to room temperature. The reaction was allowed to stir at 55° C. for 22 h. After venting the flask, Dowex® (30 mg) and water (4 mL) were added to the solution. After dialysis against water and lyophilization, the polymer was obtained as a viscous liquid (1.36 g, 57%). Product data can be found in Tables 2 and 3, entry r.

[0094] Example 13: PLLA 69 -bP(EG-co-GME)-b-PLLA 70 Synthesis of In a glove box, dry α,ω-OH-P(EG-co-GME) (400 mg, 66.7 μmol) and L-lactide (577 mg, 4.00 mmol) were dissolved in dry DCM (3 mL). DBU (6.08 mg, 40.0 μmol) dissolved in DCM (70.0 μL) was added and the resulting solution was stirred for 30 min. After addition of benzoic acid (24.4 mg, 200 μmol) in DCM (3 mL), the crude polymer was precipitated with cold diethyl ether. The last step was repeated twice. The block copolymer was obtained as a colorless solid after lyophilization from benzene (79%).

[0095] Example 14: α-BzO-P(EG 0.50 -co-GME 0.50 Synthesis of Other copolymerization conditions than temperature and solvent were kept constant compared to Example 8, and only the effects of temperature and solvent on the copolymerization were investigated. In the temperature range investigated (25-50°C), GME-EO copolymerization in toluene leads to well-defined copolymers with low polydispersity <1.10 and unimodal narrow molecular weight distribution, as can be seen in Figure 12.

[0096] As can be seen in Figure 13, α-BzO-P(EG 0.50 -co-GME 0.50 ) (toluene, 25 °C) MALDI-ToF-MS confirmed theoretical and experimental M n The values ​​show a clear overlap (2 kg mol -1 ), revealing exceptionally high end-group fidelity (>99%) known from copolymerizations in DMSO.

[0097] Product data can be found in Tables 2 and 3, entries s to u.

[0098] Discussion of results Tables 2, 3, 4, and 5 and Figures 1 through 21 show the properties of the polymers prepared, which are discussed below.

[0099] [Table 2]

[0100] [Table 3]

[0101] [Table 4]

[0102] Table 4 shows the temperature characteristics of each compound. The polymers were prepared according to Example 8 with varying amounts of monomers and benzyloxyethanol as initiator instead of diethylene glycol monomethyl ether. The cloud points of random copolymers of EO and GME were investigated by turbidimeter measurements of copolymers containing high amounts (≧59 mol%) of GME. The cloud points were defined at 50% transmittance. Benzyloxy-initiated copolymers synthesized by anionic ring-opening polymerization (AROP) in DMSO were used for the measurements.

[0103] The cloud points of the copolymers decrease with increasing amounts of GME on the polymer backbone. Despite the decrease in cloud point with increasing mol% GME, water solubility at physiological conditions is assured for all copolymers.

[0104] immunogenicity As can be seen from Table 3, items c to e and l have approximately the same molecular weight, i.e., M of approximately 4 to 5 kg / mol. n 1 shows copolymers of the present invention consisting of ethylene oxide repeat units and glycidyl methyl ether repeat units with the formula: ##STR00010## where the amount of glycidyl methyl ether repeat units increases from 16% to 49% from c to e (see Table 2, entries c to e and l). FIG. 1 shows the ELISA test results of polymers c to e and commercial mPEG. It shows the function of normalized absorbance at a wavelength of 450 nm against the log10 function of polymer concentration in nanograms per ml, thus illustrating the anti-PEG antibody interaction depending on the polymer concentration studied. The ELISA data shows that a strong effect of increasing concentrations of alkyl side chains can be observed (it is important to note that the x-axis has a logarithmic scale). With increasing amounts of GME incorporated onto the polyether structure, significantly higher polymer concentrations are required to observe interactions between the copolymer and APA. Notably, at 49 mol% GME, there is no interaction between APA and the copolymer. This means that the respective copolymer cannot be detected by APA, ie it is not immunogenic.

[0105] degree of dispersion As can be seen from Table 3, items c to e and l, all the polymers of the present invention have very low polydispersities, i.e., 1.10 or less. For visualization, the SEC traces of these polymers are shown in Figures 2 to 4 and 12. In addition, Figure 4 shows the SEC trace of mPEG. It can be clearly seen that the present invention provides polymers with very narrow molecular weight distributions.

[0106] Preparation and Purity of the Polymers of the Invention Figure 5 shows the α-BzO-P(EG 0.51 -co-GME 0.49 ), i.e., the polymer of Example 2 1 The H-NMR spectrum is shown (Tables 2 and 3, item e). The product is as obtained from Example 2 without further purification. As can be seen, the method provides not only narrow molecular weight distribution polymers, but also very pure polymers without the need for laborious purification steps, which is an important feature for use in pharmaceutical applications.

[0107] The synthesis of bifunctionally initiated α,ω-OH-P(EG-co-GME) copolymers allows the synthesis of ABA triblock copolymers. In this case, P(EG-co-GME) with two hydroxyl termini (Example 12) was used as a macroinitiator for the ring-opening polymerization of L-lactide, allowing the synthesis of PLLA-bP(EG-co-GME)-b-PLLA, where PLLA is [ka] The polymerization is catalyzed by the organic base DBU (1,8-diazabicyclo[5.4.0]undec-7-ene).

[0108] FIG. 19 shows the results of the synthesis of the macroinitiator α,ω-OH-P(EG-co-GME) (polymer of Example 12) and two PLLA-bP(EG-co-GME)-b-PLLA (PLLA 46 -bP(EG-co-GME)-b-PLLA47 FIG. 1 shows an overlay of the SEC traces of the polymer from Example 13 (wherein is the polymer from Example 13), confirming successful chain extension from the macroinitiator.

[0109] FIG. 20 shows the 1H-NMR spectrogram of Example 13 confirming the successful polymerization of L-lactide.

[0110] FIG. 21 confirms that the blocks on the copolymer are linked by covalent bonds. 1 H-DOSY-NMR is shown.

[0111] End Group Fidelity As can be seen from Table 3, the end group fidelity of all the polymers of the present invention is close to 100%. 0.51 -co-GME 0.49 ), i.e., the polymer of Example 2 (entry e in Tables 2 and 3). The only peaks visible here are those of the product molecule. There are no peaks from polymers with different end groups. This indicates that the end group fidelity of the polymer of the present invention is very high. In addition, the spectrum confirms the narrow molecular weight distribution.

[0112] soluble Figure 7 shows the α-BzO-P(EG 0.51 -co-GME 0.49), i.e., the polymer of Example 2 (item e in Tables 2 and 3). Cloud point determines the temperature at which incompatibility in water / water solutions is observed upon heating. As an example, for the copolymer with 49% GME, a cloud point can be observed at 95°C, indicating excellent water solubility of the P(EG-co-GME) copolymer. Homopolymer PEG exhibits a cloud point of ca. 100°C. All other copolymers of the invention with 26-49% GME are in between PEG and this copolymer and exhibit cloud points of 96-100°C. For copolymers with 25 mol% and lower GME incorporation, no cloud point was detected in water at temperatures ranging from 0 to 99°C. Hence, GME copolymerization has little effect on water solubility, which is characteristic of the similar structures of polyethylene glycol and methyl ethyl ether. This is an important feature of the polymers of the invention. PEG-based PEGs are preferred because they indicate that they can replace PEG in aqueous systems without causing problems of phase separation or even precipitation.

[0113] Comparison of the dispersity of end group fidelity of the polymers of the present invention with that of mPEG FIG. 8 shows the MALDI-TOF mass spectral overlap of commercial mPEG and the block copolymer of the present invention (polymer of Example 3 (entry l in Tables 2 and 3)). As can be seen, a clear shift between the macroinitiator mPEG and item l is observed, indicating successful block copolymer synthesis. The absence of macroinitiator in the MALDI-ToF-MS of item l further proves quantitative block copolymer formation. This is 44 g mol -1 This is further evidenced by the distance of the signal.

[0114] Crystallinity Table 5 shows the temperature properties of some of the polymers in Tables 2 and 3:

[0115] [Table 5]

[0116] As can be seen, the crystallinity of the polymers of the present invention is low and can be completely abrogated by the incorporation of GME monomers into the polymer structure, which prevents accumulation of the polymer in, for example, the kidney or liver.

Claims

1. A polyether polymer represented by the following formula [I]: -(CH ２ CHR-O-) ｍ - [I] During the ceremony, - 10 to 90% of the residues R are hydrogen and 10 to 90% of the residues R are selected, independently of one another, from the group consisting of methoxymethyl, ethoxymethyl, n-propoxymethyl and isopropoxymethyl; at least 1% of the residues R are methoxymethyl; up to 50% of the residues R may be selected from the group consisting of ethoxymethyl, n-propoxymethyl and isopropoxymethyl; - and -m is in the range of 10 to 1000, A polyether polymer characterized by a polydispersity of less than 1.15 as measured by size exclusion chromatography in DMF, calibrated with PEG standards.

2. 2. The polyether polymer of claim 1, wherein the polyether is a poly(glycidyl methyl ether-co-ethylene oxide) copolymer.

3. 3. A polyether polymer according to claim 1, characterized in that 30 to 70% of the residues R are hydrogen, the remaining residues R being methoxymethyl.

4. 4. The polyether polymer according to claim 1, characterized in that the polymer is a random or statistical copolymer.

5. The polyether polymer according to any one of claims 1 to 4, represented by the following formula [II]: X-(CH ２ CHR-O-) ｍ CH ２ CHR-Y [II] wherein X is selected from the group consisting of hydrogen, alkyl, hydroxy, sulfanyl, C1-C10 alkoxy, C1-C10 thioalkoxy, amino, amino-C1-C10 alkoxy, dibenzylamino-C1-C10 alkoxy, amide, N-heterocyclic carbene, and N-heterocyclic olefin; Y is hydrogen, hydroxy, alkoxy, -CH ２ selected from the group consisting of -C(=O)-R, -CHO, alkylcarbonyloxy, alkyoxycarbonyloxy, amine, C1-C10 alkylamine, carboxamide, azide, halogen, sulfanyl, thioalkoxy, N-succinimidyl carbonate, and sulfonate; X and / or Y may also be selected from the group consisting of low molecular weight drugs, nanocarriers, liposomal structures, peptides, polypeptides, proteins, glycoproteins, polynucleotides, polysaccharides, lipid structures, liposomes, surfaces, and interfaces, which are bound to the polymer directly by a covalent bond or by a spacer; m ranges from 9 to 999, A polyether polymer characterized by a polydispersity of less than 1.15 as measured by size exclusion chromatography in DMF, calibrated with PEG standards.

6. 6. The polyether polymer of claim 5, wherein X is alkoxy and Y is hydroxy.

7. 6. The polyether polymer of claim 5, wherein X and Y are each hydroxy.

8. The polyether polymer according to claims 1 to 4, represented by the following formula [II]: X-(CH ２ CHR-O-) ｍ CH ２ CHR-Y [II] wherein X is selected from the group consisting of hydrogen or X′; wherein X' is selected from the group consisting of: 【Chemistry 1】 where R" = H, or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl; p=1, 2, 3, 4, or 5; k=5 to 500; 【Chemistry 2】 where R" = H, or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl; p=1, 2, 3, 4, or 5; k=5 to 500; 【Chemistry 3】 where R" = H, or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl; q=3, 4, or 5; k=5 to 500; and 【Chemistry 4】 wherein k=5 to 500; wherein Y is Z-W, i.e., composed of the substituents Z and W linked by a covalent bond; During the ceremony, Z is -O-R'-O-; W is -R-CHCH ２ -(O-CHRCH2-) ｍ -V; wherein V is X or X'; wherein R' is selected from the group consisting of: 【Chemistry 5】 During the ceremony, R" = H, or alkyl, alkenyl, aryl, alkoxymethyl, alkenyloxymethyl, aryloxymethyl, aminomethyl, and thioalkoxymethyl; s=0 to 20; t=0 to 20; Further R' is selected from: 【Chemistry 6】 During the ceremony, m ranges from 9 to 999, A polyether polymer characterized by a polydispersity of less than 1.15 as measured by size exclusion chromatography in DMF, calibrated with PEG standards.

9. 9. A polyether polymer according to claim 5 or 8, characterised in that the end group fidelity of the polymer is at least 95% for group X and / or for group Y.

10. A conjugate comprising a polyether polymer according to any one of claims 1 to 9 and a substrate.

11. The conjugate of claim 10, characterized in that the substrate is selected from the group consisting of low molecular weight drugs, nanocarriers, liposomal structures, peptides, polypeptides, proteins, glycoproteins, polynucleotides, polysaccharides, lipid structures, liposomes, surfaces, and interfaces.

12. A process for the preparation of the polyether polymers according to any one of claims 1 to 11 by anionic ring-opening copolymerization comprising the steps of: - Anion An － To provide - expression 【Chemistry 7】 wherein R is as defined in any one of claims 1 to 8, allowing the polymerization to proceed at a temperature in the range of from -10 to 90°C; 1. A process for the preparation of a polyether polymer, wherein the monomer contains less than 1 wt. % epichlorohydrin.

13. 13. The process of claim 12, wherein the steps of adding at least one monomer and allowing polymerization to proceed are repeated at least once, whereby at least one monomer different from the first is used.

14. A － The counter ion for the anion is Na ＋ , K ＋ , and Cs ＋ 14. The process according to claim 12 or 13, characterized in that the said compound is selected from the group consisting of:

15. Use of a polyether polymer according to any one of claims 1 to 9 for the preparation of a conjugate of the polymer with a biologically active compound.

16. Use according to claim 15 for the preparation of conjugated lipids for use in a vaccine, in particular based on lipid nanoparticles, characterized in that these nanoparticles are preferably nanoparticles used against COVID-19.

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