High-dose therapy with cytarabine (araC) is a standard treatment for aggressive non-Hodgkin lymphomas, but its efficacy is limited by rapid enzymatic degradation. To overcome this, araC was conjugated to N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers to form linear and star-like nanomedicines using six different spacers: 3-aminopropanoyl, 5-pentanoyl, 6-aminohexanoyl, 4-aminobenzoyl, glycyl, and diglycyl. The conjugates contained 12.5-14.7 wt% araC and exhibited distinct hydrolytic release profiles at pH 7.4. LC1 (3-aminopropanoyl) and LC6 (diglycyl) released the drug most rapidly (~80% bound after 72 h), and LC2, LC3, and the star conjugate SC1 showed intermediate stability (~90%), while LC4 (4-aminobenzoyl) was most stable (~95%). In vivo, all conjugates markedly suppressed tumor growth in patient-derived xenograft models of mantle cell and Burkitt lymphoma compared with free araC. LC1 and LC2 provided the most durable tumor control, delaying regrowth beyond 40 days, and SC1 achieved comparable efficacy at a reduced araC-equivalent dose (2 mg/mouse vs. 3 mg/mouse for linear conjugates). These results demonstrate that spacer structure critically influences drug release and identify LC1 and LC2 as promising candidates for further development in lymphoma therapy.

1st Department of Internal Medicine Charles University General Hospital Prague Czech Republic U Nemocnice 2 128 08 Prague Czech Republic

Institute of Macromolecular Chemistry Czech Academy of Sciences Heyrovského nám 2 162 00 Prague Czech Republic

Institute of Pathological Physiology 1st Faculty of Medicine Charles University Prague U Nemocnice 5 128 53 Prague Czech Republic

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Minko T., Dharap S.S., Pakunlu R.I., Wang Y. Molecular targeting of drug delivery systems to cancer. Curr. Drug Targets. 2004;5:389–406. doi: 10.2174/1389450043345443. PubMed DOI

Nan A., Ghandehari H., Hebert C., Siavash H., Nikitakis N., Reynolds M., Sauk J.J. Water-soluble polymers for targeted drug delivery to human squamous carcinoma of head and neck. J. Drug Target. 2005;13:189–197. doi: 10.1080/10611860500065187. PubMed DOI

Etrych T., Kovář L., Strohalm J., Chytil P., Ríhová B. Ulbrich. Biodegradable star HPMA polymer-drug conjugates: Biodegradability, distribution and anti-tumor efficacy. J. Control. Release. 2011;154:241–248. doi: 10.1016/j.jconrel.2011.06.015. PubMed DOI

Pechar M., Pola R., Studenovský M., Bláhová M., Grosmanová E., Dydowiczová A., Filipová M., Islam R., Gao S., Fang J., et al. Polymer nanomedicines with enzymatically triggered activation: A comparative study of in vitro and in vivo anti-cancer efficacy related to the spacer structure. Nanomed. Nanotechnol. Biol. Med. 2022;46:102597. doi: 10.1016/j.nano.2022.102597. PubMed DOI

Zhang R., Luo K., Yang J., Sima M., Sun Y., Janát-Amsbury M.M., Kopeček J. Synthesis and evaluation of a backbone biodegradable multiblock HPMA copolymer nanocarrier for the systemic delivery of paclitaxel. J. Control. Release. 2013;166:66–74. doi: 10.1016/j.jconrel.2012.12.009. PubMed DOI PMC

Zhou P., Li Z., Chau Y. Synthesis, characterization, and in vivo evaluation of poly(ethylene oxide-co-glycidol)-platinate conjugate. Eur. J. Pharm. Sci. 2010;41:464–472. doi: 10.1016/j.ejps.2010.07.014. PubMed DOI

Nichifor M., Schacht E.H., Seymour L.W., Anderson D., Shoaibi M. Cytotoxicity and anticancer activity of macromolecular prodrugs of 5-fluorouracil. J. Bioact. Compat. Polym. 1997;12:265–281. doi: 10.1177/088391159701200401. DOI

Takemoto H., Inaba T., Nomoto T., Matsui M., Liu X., Toyoda M., Honda Y., Taniwaki K., Yamada N., Kim J., et al. Polymeric modification of gemcitabine via cyclic acetal linkage for enhanced anticancer potency with negligible side effects. Biomaterials. 2020;235:119804. doi: 10.1016/j.biomaterials.2020.119804. PubMed DOI

Kopeček J., Yang J. Polymer nanomedicines. Adv. Drug Deliv. Rev. 2020;156:40–64. doi: 10.1016/j.addr.2020.07.020. PubMed DOI PMC

Kantarjian H., Barlogie B., Plunkett W., Velasquez W., McLaughlin P., Riggs S., Cabanillas F. High-dose cytosine arabinoside in non-Hodgkin’s lymphoma. J. Clin. Oncol. 1983;1:689–694. doi: 10.1200/JCO.1983.1.11.689. PubMed DOI

Abraham A., Varatharajan S., Abbas S., Zhang W., Shaji R.V., Ahmed R., Abraham A., George B., Srivastava A., Chandy M., et al. Cytidine deaminase genetic variants influence RNA expression and cytarabine cytotoxicity in acute myeloid leukemia. Pharmacogenomics. 2012;13:269–282. doi: 10.2217/pgs.11.149. PubMed DOI

Chamberlain M.C. Neurotoxicity of intra-CSF liposomal cytarabine (DepoCyt) administered for the treatment of leptomeningeal metastases: A retrospective case series. J. Neuro-Oncology. 2012;108:495–502. doi: 10.1007/s11060-012-0880-x. PubMed DOI

Ostermann K., Pels H., Kowoll A., Kuhnhenn J., Schlegel U. Neurologic complications after intrathecal liposomal cytarabine in combination with systemic polychemotherapy in primary CNS lymphoma. J. Neuro-Oncology. 2011;103:635–640. doi: 10.1007/s11060-010-0435-y. PubMed DOI

Salehi B., Selamoglu Z., Mileski K.S., Pezzani R., Redaelli M., Cho W.C., Kobarfard F., Rajabi S., Martorell M., Kumar P., et al. Liposomal cytarabine as cancer therapy: From chemistry to clinical applications. Biomolecules. 2019;9:773. doi: 10.3390/biom9120773. PubMed DOI PMC

Chhikara B.S., Parang K. Development of cytarabine prodrugs and delivery systems for leukemia treatment. Expert Opin. Drug Deliv. 2010;7:1225–1238. doi: 10.1517/17425247.2010.527330. PubMed DOI

Liu R., Zhang J., Zhang D., Wang K., Luan Y. Self-assembling nanoparticles based on cytarabine prodrugs: Synthesis, characterization and antitumor evaluation. J. Mol. Liq. 2018;251:178–184. doi: 10.1016/j.molliq.2017.12.086. DOI

Pola R., Pokorná E., Vočková P., Böhmová E., Pechar M., Karolová J., Pankrác J., Šefc L., Helman K., Trněný M., et al. Cytarabine nanotherapeutics with increased stability and enhanced lymphoma uptake for tailored highly effective therapy of mantle cell lymphoma. Acta Biomater. 2021;119:349–359. doi: 10.1016/j.actbio.2020.11.014. PubMed DOI

Ulbrich K., Šubr V., Strohalm J., Plocová D., Jelınková M., Řıhová B. Polymeric drugs based on conjugates of synthetic and natural macromolecules: I. Synthesis and physico-chemical characterisation. J. Control. Release. 2000;64:63–79. doi: 10.1016/S0168-3659(99)00141-8. PubMed DOI

Pola R., Laga R., Ulbrich K., Sieglová I., Král V., Fábry M., Kabešová M., Kovář M., Pechar M. Polymer Therapeutics with a Coiled Coil Motif Targeted against Murine BCL1 Leukemia. Biomacromolecules. 2013;14:881–889. doi: 10.1021/bm3019592. PubMed DOI

Pola R., Janoušková O., Etrych T. Etrych. The pH-Dependent and Enzymatic Release of Cytarabine From Hydrophilic Polymer Conjugates. Physiol. Res. 2016;65:S225–S232. doi: 10.33549/physiolres.933424. PubMed DOI

Perrier S., Takolpuckdee P., Mars C.A. Reversible Addition−Fragmentation Chain Transfer Polymerization: End Group Modification for Functionalized Polymers and Chain Transfer Agent Recovery. Macromolecules. 2005;38:2033–2036. doi: 10.1021/ma047611m. DOI

Lidický O., Renešová N., Kudláčová J., Filipová M., Běláková T., Kovaříková P., Manakov D., Pankrác J., Dolníková A., Pokorná E., et al. Antibody polymer drug conjugates with increased drug to antibody ratio: CD38-targeting nanomedicines for innovative therapy of relapsed lymphomas. J. Control. Release. 2025;384:113876. doi: 10.1016/j.jconrel.2025.113876. PubMed DOI

Jakša R., Karolová J., Svatoň M., Kazantsev D., Grajciarová M., Pokorná E., Tonar Z., Klánová M., Winkowska L., Maláriková D., et al. Complex genetic and histopathological study of 15 patient-derived xenografts of aggressive lymphomas. Lab. Investig. 2022;102:957–965. doi: 10.1038/s41374-022-00784-w. PubMed DOI PMC

Willig F., Greiner I., Stork H., Schmidt F.H. Leucinaminopeptidase-(Arylamidase-) Aktivität im Serum: Bestimmung mit Leucin-p-nitroanilid als Substrat. Klin. Wochenschr. 1967;45:474–481. doi: 10.1007/BF01717434. PubMed DOI

Laizure S.C., Herring V., Hu Z., Witbrodt K., Parker R.B. The role of human carboxylesterases in drug metabolism: Have we overlooked their importance? Pharmacotherapy. 2013;33:210–222. doi: 10.1002/phar.1194. PubMed DOI PMC

Jasiecki J., Szczoczarz A., Cysewski D., Lewandowski K., Skowron P., Waleron K., Wasąg B. Butyrylcholinesterase–Protein Interactions in Human Serum. Int. J. Mol. Sci. 2021;22:10662. doi: 10.3390/ijms221910662. PubMed DOI PMC