Methods for the preparation of targeting agent functionalized diblock copolymers for use in fabrication of therapeutic targeted nanoparticles

Abstract

This application provides methods of making nanoparticles using pre-functionalized poly(ethylene glycol) (also referred to as PEG) as a macroinitiator for the synthesis of diblock copolymers. These diblock copolymers comprise a poly(ethylene glycol) block bearing a targeting agent at its terminus and a second biocompatible and biodegradable hydrophobic polymer block (e.g. a poly(ester)). The poly(ethylene glycol) is hetero-bifunctional with a targeting moiety (agent) covalently bound to its α terminus and a polymerization initiating functional group (e.g., a hydroxyl group) present on its ω terminus. Ring opening polymerization yields the desired poly(ester)-poly(ethylene glycol)-targeting agent polymer that is used to impart targeting capability to therapeutic nanoparticles. This “polymerization from” approach typically employs precursors of the targeting agent wherein the reactivity of functional groups of the targeting agent is masked using protecting groups. Also described is a “coupling to” that utilized the poly(ethylene glycol)-targeting agent conjugate where the targeting agent remains in its native un-protected form. This method uses “orthogonal” chemistry that exhibit no cross reactivity towards functional groups typically found within targeting agents of interest. Nanoparticles produced according to the disclosed methods as well as their use in the treatment of various diseases are also provided.

1 . A method of preparing a nanoparticle comprising:
 providing a targeting agent;   providing a functionalized poly(ethylene glycol) (PEG) polymer;   providing a targeting agent ligand;   reacting the functionalized poly(ethylene glycol) polymer with the targeting agent to form a targeting agent-PEG polymer complex; and   mixing the targeting agent-PEG polymer complex with a second polymer and a therapeutic agent to form a nanoparticle.   
   
   
       2 . The method of  claim 1 , wherein the poly(ethylene glycol) is hetero-bifunctional and said targeting agent is covalently bound to the α terminus of said poly(ethylene glycol) and at least one polymerization initiating functional group is present on the ω terminus of said poly(ethylene glycol). 
   
   
       3 . The method of  claim 2 , wherein said at least one polymerization initiating functional group is a hydroxyl (—OH) group or an amine (—NH 2 ) group at the free ω terminus that reacts with a second copolymer. 
   
   
       4 . The method of  claim 3 , wherein the second polymer comprises a blend of two or more polymers and contains at least one functional group that reacts the functional group present at the free ω terminus of said poly(ethylene glycol) and said at least one functional group of said blend of two or more polymers is a hydroxyl group, a NHS group or an amine group. 
   
   
       5 . The method of  claim 1 , wherein the second polymer or the copolymer is a polyester copolymer that contains at least one functional group selected from a hydroxyl group, a NHS group or an amine group and that reacts the functional group present at the free ω terminus of said poly(ethylene glycol). 
   
   
       6 . The method of  claim 4 , wherein the second polymer or the copolymer is a polyester copolymer that contains at least one functional group selected from a hydroxyl group, a NHS group or an amine group and that reacts the functional group present at the free ω terminus of said poly(ethylene glycol). 
   
   
       7 . The method of  claim 6 , wherein said polyester copolymer comprises a heteropolymer or a homopolymer. 
   
   
       8 . The method of  claim 7 , wherein said heteropolymer comprises lactic acid and glycolic acid units or poly(lactic acid-co-glycolic acid) and poly(lactide-co-glycolide) units (PLGA); and said homopolymer comprises glycolic acid units (PGA), lactic acid units (PLA), poly-L-lactic acid units, poly-D-lactic acid units, poly-D,L-lactic acid units, poly-L-lactide units, poly-D-lactide units or poly-D,L-lactide units. 
   
   
       9 . The method of  claim 6 , wherein said polyester copolymer is selected from polyhydroxyacids; PEGylated polymers and copolymers of lactide units and glycolide units, PEGylated PLA, PEGylated PGA, PEGylated PLGA, polyanhydrides, poly(ortho ester) PEGylated poly(ortho ester), poly(caprolactone), PEGylated poly(caprolactone), polylysine, PEGylated polylysine, poly(ethylene inline), PEGylated poly(ethylene imine), poly(L-lactide-co-L-lysine), poly(serine ester), poly(4-hydroxy-L-proline ester), poly[a-(4-aminobutyl)-L-glycolic acid] or derivatives thereof. 
   
   
       10 . The method of  claim 1 , wherein free carboxylic acid groups or free hydroxyl groups on said targeting agent are protected prior to reacting the functionalized poly(ethylene glycol) polymer with the targeting agent to form a targeting agent-PEG polymer complex. 
   
   
       11 . The method of  claim 4 , wherein said functional group of said second polymer is an amine group that reacts with a hydroxyl group or carboxylic acid group on said targeting agent-PEG complex. 
   
   
       12 . The method of  claim 4 , wherein said functional group of said second polymer is a hydroxyl group or an NHS group that reacts with an amine group on said targeting agent-PEG complex. 
   
   
       13 . The method of  claim 6 , wherein said functional group of said second polymer or said copolymer is an amine group that reacts with a hydroxyl group or carboxylic acid group on said targeting agent-PEG complex. 
   
   
       14 . The method of  claim 6 , wherein said functional group of said second polymer or said copolymer is a NHS or hydroxyl group that reacts with an amine group on said targeting agent-PEG complex. 
   
   
       15 . The method of  claim 1 , wherein said second polymer is a blend of at least two polymers which can be the same or different polymer, wherein the first of said at least two polymers contains at least one hydroxyl group or an NHS group as a functional group and the second of said at least two polymers contains at least one amine group as said functional group. 
   
   
       16 . The method of  claim 1 , wherein said therapeutic agent is an antibiotic, anti-cancer agent, antiviral agent, anti-inflammatory agent a diagnostic agent, a vaccine antigen or a nutraceutical. 
   
   
       17 . The method of  claim 16 , wherein said therapeutic agent is/are penicillins, aminopenicillins, penicillins in conjunction with penicillinase inhibitor and/or anti-fungal agents, cephalosporins, cephamycins, carbapenems, fluoroquinolones, tetracyclines, macrolides, aminoglycosides, erythromycin, bacitracin zinc, polymyxin, polymyxin B sulfates, neomycin, gentamycin, tobramycin, gramicidin, ciprofloxacin, trimethoprim, ofloxacin, levofloxacin, gatifloxacin, moxifloxacin, norfloxacin, sodium sulfacetamide, chloramphenicol, tetracycline, azithromycin, clarithyromycin, trimethoprim sulfate, bacitracin, corticosteroids, medrysone, prednisolone, prednisolone acetate, prednisolone sodium phosphate, fluormetholone, dexamethasone, dexamethasone sodium phosphate, betamethasone, fluorometholone, antazoline, fluorometholone acetate, rimexolone, loteprednol etabonate, diclofenac (diclofenac sodium), ketorolac, ketorolac tromethamine, hydrocortisone, bromfenac, flurbiprofen, antazoline, xylometazoline, cromolyn sodium, lodoxamide tromethamine, olopatadine HCl, nedocromil sodium, ketotifen fumurate, levocabastine HCL, azelastine HCL, pemirolast (pemirolast potassium), epinastine HCL, naphazoline HCL, emedastine, antazoline, pheniramine, sodium cromoglycate, N-acetyl-aspartyl glutamic acid, amlexanox, 5-fluorouracil (5-FU), CPT-11, 10-hydroxy-7-ethylcamptothecin (SN38), S-I capecitabine, ftorafur, 5′deoxyfluorouridine, UFT, eniluracil, deoxycytidine, 5-azacytosine, 5-azadeoxycytosine, allopurinol, 2-chloroadenosine, aminopterin, methylene-10-deazaminopterin (MDAM), oxaplatin, picoplatin, tetraplatin, satraplatin, platinum-DACH, ormaplatin, CI-973, JM-216, and analogs thereof, 9-aminocamptothecin, 10,11-methylenedioxycamptothecin, karenitecin, 9-nitrocamptothecin, TAS 103, L-phenylalanine mustard, ifosphamidemefosphamide, trophosphamide carmustine, epothilones A-E, tomudex, 6-mercaptopurine, 6-thioguanine, karenitecin, acyclovir, valacyclovir, ganciclovir, amantadine, rimantadine, lamivudine, zidovudine, bevacizumab, trastuzumab, rituximab,20-epi-1α, 25 dihydroxyvitamin D3, 4-ipomeanol, 5-ethynyluracil, 9-dihydrotaxol, abiraterone, acivicin, aclarubicin, acodazole hydrochloride, acronine, acylfiilvene, adecypenol, adozelesin, aldesleukin, all-tk antagonists, altretamine, ambamustine, ambomycin, ametantrone acetate, amidox, amifostine, aminoglutethimide, aminolevulinic acid, amrubicin, amsacrine, anagrelide, anastrozole, andrographolide, angiogenesis inhibitors, antagonist D, antagonist G, antarelix, anthramycin, anti-dorsalizing morphogenetic protein-1, antiestrogen, antineoplaston, antisense oligonucleotides, aphidicolin glycinate, apoptosis gene modulators, apoptosis regulators, apurinic acid, ARA-CDP-DL-PTBA, arginine deaminase, asparaginase, asperlin, asulacrine, atamestane, atrimustine, axinastatin 1, axinastatin 2, axinastatin 3, azacitidine, azasetron, azatoxin, azatyrosine, azetepa, azotomycin, baccatin III derivatives, balanol, batimastat, benzochlorins, benzodepa, benzoylstaurosporine, beta lactam derivatives, beta-alethine, betaclamycin B, betulinic acid, BFGF inhibitor, bicalutamide, bisantrene, bisantrene hydrochloride, bisazuidinylspermine, bisnafide, bisnafide dimesylate, bistratene A, bizelesin, bleomycin, bleomycin sulfate, BRC/ABL antagonists, breflate, brequinar sodium, bropirimine, budotitane, busulfan, buthionine sulfoximine, cactinomycin, calcipotriol, calphostin C, calusterone, camptothecin derivatives, canarypox IL-2, capecitabine, caraceraide, carbetimer, carboplatin, carboxamide-amino-triazole, carboxyamidotriazole, carest M3, carmustine, earn 700, cartilage derived inhibitor, carubicin hydrochloride, carzelesin, casein kinase inhibitors, castanosperrnine, cecropin B, cedefingol, cetrorelix, chlorambucil, chlorins, chloroquinoxaline sulfonamide, cicaprost, cirolemycin, cisplatin, cis-porphyrin, cladribine, clomifene analogs, clotrimazole, collismycin A, collismycin B, combretastatin A4, combretastatin analog, conagenin, crambescidin 816, crisnatol, crisnatol mesylate, cryptophycin 8, cryptophycin A derivatives, curacin A, cyclopentanthraquinones, cyclophosphamide, cycloplatam, cypemycin, cytarabine, cytarabine ocfosfate, cytolytic factor, cytostatin, dacarbazine, dacliximab, dactinomycin, daunorubicin hydrochloride, decitabine, dehydrodidemnin B, deslorelin, dexifosfamide, dexormaplatin, dexrazoxane, dexverapamil, dezaguanine, dezaguanine mesylate, diaziquone, didemnin B, didox, diethyhiorspermine, dihydro-5-azacytidine, dioxamycin, diphenyl spiromustine, docetaxel, docosanol, dolasetron, doxifluridine, doxorubicin, doxorubicin hydrochloride, droloxifene, droloxifene citrate, dromostanolone propionate, dronabinol, duazomycin, duocannycin SA, ebselen, ecomustine, edatrexate, edelfosine, edrecolomab, eflomithine, eflomithine hydrochloride, elemene, elsarnitrucin, emitefur, enloplatin, enpromate, epipropidine, epirubicin, epirubicin hydrochloride, epristeride, erbulozole, erythrocyte gene therapy vector system, esorubicin hydrochloride, estramustine, estramustine analog, estramustine phosphate sodium, estrogen agonists, estrogen antagonists, etanidazole, etoposide, etoposide phosphate, etoprine, exemestane, fadrozole, fadrozole hydrochloride, fazarabine, fenretinide, filgrastim, finasteride, flavopiridol, flezelastine, floxuridine, fluasterone, fludarabine, fludarabine phosphate, fluorodaunorunicin hydrochloride, fluorouracil, fluorocitabine, forfenimex, formestane, fosquidone, fostriecin, fostriecin sodium, fotemustine, gadolinium texaphyrin, gallium nitrate, galocitabine, ganirelix, gelatinase inhibitors, gemcitabine, gemcitabine hydrochloride, glutathione inhibitors, hepsulfam, heregulin, hexamethylene bisacetamide, hydroxyurea, hypericin, ibandronic acid, idarubicin, idarubicin hydrochloride, idoxifene, idramantone, ifosfamide, ihnofosine, ilomastat, imidazoacridones, imiquimod, immunostimulant peptides, insulin-like growth factor-1 receptor inhibitor, interferon agonists, interferon alpha-2A, interferon alpha-2B, interferon alpha-N1, interferon alpha-N3, interferon beta-IA, interferon gamma-IB, interferons, interleukins, iobenguane, iododoxorubicin, iproplatm, irinotecan, irinotecan hydrochloride, iroplact, irsogladine, isobengazole, isohomohalicondrin B, itasetron, jasplakinolide, kahalalide F, lamellarin-N triacetate, lanreotide, lanreotide acetate, leinamycin, lenograstim, lentinan sulfate, leptolstatin, letrozole, leukemia inhibiting factor, leukocyte alpha interferon, leuprolide acetate, leuprolide/estrogen/progesterone, leuprorelin, levamisole, liarozole, liarozole hydrochloride, linear polyamine analog, lipophilic disaccharide peptide, lipophilic platinum compounds, lissoclinamide, lobaplatin, lombricine, lometrexol, lometrexol sodium, lomustine, lonidamine, losoxantrone, losoxantrone hydrochloride, lovastatin, loxoribine, lurtotecan, lutetium texaphyrin lysofylline, lytic peptides, maitansine, mannostatin A, marimastat, masoprocol, maspin, matrilysin inhibitors, matrix metalloproteinase inhibitors, maytansine, mechlorethamine hydrochloride, megestrol acetate, melengestrol acetate, melphalan, menogaril, merbarone, mercaptopurine, meterelin, methioninase, methotrexate, methotrexate sodium, metoclopramide, metoprine, meturedepa, macroalgal protein kinase C uihibitors, MIF inhibitor, mifepristone, miltefosine, mirimostim, mismatched double stranded RNA, mitindomide, mitocarcin, mitocromin, mitogillin, mitoguazone, mitolactol, mitomalcin, mitomycin, mitomycin analogs, mitonafide, mitosper, mitotane, mitotoxin fibroblast growth factor-saporin, mitoxantrone, mitoxantrone hydrochloride, mofarotene, molgramostim, monoclonal antibody, human chorionic gonadotrophin, monophosphoryl lipid a/myobacterium cell wall SK, mopidamol, multiple drug resistance gene inhibitor, mustard anticancer agent, mycaperoxide B, mycobacterial cell wall extract, mycophenolic acid, myriaporone, n-acetyldinaline, nafarelin, nagrestip, naloxone/pentazocine, napavin, naphterpin, nartograstim, nedaplatin, nemorubicin, neridronic acid, neutral endopeptidase, nilutamide, nisamycin, nitric oxide modulators, nitroxide antioxidant, nitrullyn, nocodazole, nogalamycin, n-substituted benzamides, O6-benzylguanine, octreotide, okicenone, oligonucleotides, onapristone, ondansetron, oracin, oral cytokine inducer, ormaplatin, osaterone, oxaliplatin, oxaunomycin, oxisuran, paclitaxel, paclitaxel analogs, paclitaxel derivatives, palauamine, palmitoylrhizoxin, pamidronic acid, panaxytriol, panomifene, parabactin, pazelliptine, pegaspargase, peldesine, peliomycin, pentamustine, pentosan polysulfate sodium, pentostatin, pentrozole, peplomycin sulfate, perflubron, perfosfamide, perillyl alcohol, phenazinomycin, phenylacetate, phosphatase inhibitors, picibanil, pilocarpine hydrochloride, pipobroman, piposulfan, pirarubicin, piritrexim, piroxantrone hydrochloride, placetin A, placetin B, plasminogen activator inhibitor, platinum complex, platinum compounds, platinum-triamine complex, plicamycin, plomestane, porfimer sodium, porfiromycin, prednimustine, procarbazine hydrochloride, propyl bis-acridone, prostaglandin J2, prostatic carcinoma antiandrogen, proteasome inhibitors, protein A-based immune modulator, protein kinase C inhibitor, protein tyrosine phosphatase inhibitors, purine nucleoside phosphorylase inhibitors, puromycin, puromycin hydrochloride, purpurins, pyrazorurin, pyrazoloacridine, pyridoxylated hemoglobin polyoxyethylene conjugate, RAF antagonists, raltitrexed, ramosetron, RAS farnesyl protein transferase inhibitors, RAS inhibitors, RAS-GAP inhibitor, retelliptine demethylated, rhenium RE 186 etidronate, rhizoxin, riboprine, ribozymes, RH retinamide, RNAi, rogletimide, rohitukine, romurtide, roquinimex, rubiginone B1, ruboxyl, safingol, safingol hydrochloride, saintopin, sarcnu, sarcophytol A, sargramostim, SDI1 mimetics, semustine, senescence derived inhibitor 1, sense oligonucleotides, signal transduction inhibitors, signal transduction modulators, simtrazene, single chain antigen binding protein, sizofuran, sobuzoxane, sodium borocaptate, sodium phenylacetate, solverol, somatomedin binding protein, sonermin, sparfosafe sodium, sparfosic acid, sparsomycin, spicamycin D, spirogermanium hydrochloride, spiromustine, spiroplatin, splenopentin, spongistatin 1, squalamine, stem cell inhibitor, stem-cell division inhibitors, stipiamide, streptonigrin, streptozocin, stromelysin inhibitors, sulfinosine, sulofenur, superactive vasoactive intestinal peptide antagonist, suradista, suramin, swainsonine, synthetic glycosaminoglycans, talisomycin, tallimustine, tamoxifen methiodide, tauromustine, tazarotene, tecogalan sodium, tegafur, tellurapyrylium, telomerase inhibitors, teloxantrone hydrochloride, temoporfin, temozolomide, teniposide, teroxirone, testolactone, tetrachlorodecaoxide, tetrazomine, thaliblastine, thalidomide, thiamiprine, thiocoraline, thioguanine, thiotepa, thrombopoietin, thrombopoietin mimetic, thymalfasin, thymopoietin receptor agonist, thymotrinan, thyroid stimulating hormone, tiazofurin, tin ethyl etiopurpurin, tirapazamine, titanocene dichloride, topotecan hydrochloride, topsentin, toremifene, toremifene citrate, totipotent stem cell factor, translation inhibitors, trestolone acetate, tretinoin, triacetyluridine, triciribine, triciribine phosphate, trimetrexate, trimetrexate glucuronate, triptorelin, tropisetron, tubulozole hydrochloride, turosteride, tyrosine kinase inhibitors, tyrphostins, UBC inhibitors, ubenimex, uracil mustard, uredepa, urogenital sinus-derived growth inhibitory factor, urokinase receptor antagonists, vapreotide, variolin B, velaresol, veramine, verdins, verteporfin, vinblastine sulfate, vincristine sulfate, vindesine, vindesine sulfate, vinepidine sulfate, vinglycinate sulfate, vinleurosine sulfate, vinorelbine, vinorelbine tartrate, vinrosidine sulfate, vinxaltine, vinzolidine sulfate, vitaxin, vorozole, zanoterone, zeniplatin, zilascorb, zinostatin, zinostatin stimalamer, or zorubicin hydrochloride, siRNA or any combinations thereof. 
   
   
       18 . The method of  claim 1 , wherein said at least one targeting agent is selected from antibodies, PMSA ligands and polypeptides that bind to epidermal growth factor receptor (EGFR), somatostatin receptor (SSTR), insulin-like growth factor receptor, folic acid-receptor, HER2 receptor, interleukin-13 receptor, gastrin-releasing peptide receptor, CD30, vasoactive intestinal peptide receptor, gastrin receptor, prostate-specific antigen, and/or the estrogen receptor. 
   
   
       19 . The method of  claim 1 , wherein said method is performed in an aqueous medium. 
   
   
       20 . The method of  claim 1 , wherein said method is performed in an organic solvent. 
   
   
       21 . A nanoparticle produced according to the methods of  claim 1 . 
   
   
       22 . A composition comprising the nanoparticle of  claim 21  and a pharmaceutically acceptable carrier. 
   
   
       23 . A method of treating a disease comprising the administration of a nanoparticle according to  claim 21  to a subject in an amount sufficient to treat said disease. 
   
   
       24 . The method of  claim 23 , wherein said disease is selected from lung cancer, breast cancer, prostate cancer, head and neck cancer, ovarian cancer, skin cancer, testicular cancer, pancreatic cancer, esophageal cancer, colorectal cancer, kidney cancer, cervical cancer, gastrointestinal cancer, viral infections, bacterial infections or inflammation. 
   
   
       25 . A polymer produced according to the method of  claim 1 , said polymer comprising a targeting agent covalently bound to the α terminus of a poly(ethylene glycol) polymer and at least one second polymer covalently bound to said poly(ethylene glycol) polymer via a functional group present on the ω terminus of said poly(ethylene glycol).