# From PEGylation to Next-Generation Polymers: Overcoming Biological Barriers—A Review

**Authors:** Rizvangul Iminova, Gulzat Berganayeva, Aliya Zhurtbayeva, Lazzat Abdurakhmanova, Almagul Almabekova, Daniil Shepilov, Gulzira Vassilina, Akmaral Nurmahanova, Gulfairuz Kairalapova, Moldyr Dyusebaeva

PMC · DOI: 10.3390/molecules31040675 · Molecules · 2026-02-15

## TL;DR

This paper reviews how new polymers are replacing PEG in drug delivery to improve safety and effectiveness.

## Contribution

The paper presents a comprehensive review of next-generation polymers designed to overcome PEG's limitations in drug delivery.

## Key findings

- PEG's use is being challenged due to immunogenicity and limited biodegradability.
- New polymers offer better biocompatibility and control over drug delivery.
- These advances signal a shift toward safer and more versatile therapeutic systems.

## Abstract

Poly(ethylene glycol) (PEG) has long stood as the prevailing standard in drug delivery, celebrated for its capacity to enhance solubility, extend circulation, and improve pharmacological performance. Nevertheless, the emergence of anti-PEG antibodies, accelerated clearance, and limited biodegradability increasingly undermine its role as a universal solution. In response, a new generation of polymers has been developed to address these shortcomings, offering the potential to sustain or surpass PEG’s benefits while mitigating immunogenicity, improving biocompatibility, and enabling finer control over therapeutic fate. This review examines current research to articulate a coherent perspective on the replacement of PEG, tracing how advances in polymer design are reshaping the foundations of targeted drug delivery. Taken together, these developments signal not only a corrective to the limitations of PEG but also a broader paradigm shift toward safer, more versatile, and clinically translatable systems that define the next frontier in precision therapeutics.

## Linked entities

- **Chemicals:** Poly(ethylene glycol) (PubChem CID 9033), PEG (PubChem CID 174)

## Full-text entities

- **Genes:** SCARB1 (scavenger receptor class B member 1) [NCBI Gene 949] {aka CD36L1, CLA-1, CLA1, HDLCQ6, HDLQTL6, SR-BI}, NR5A1 (nuclear receptor subfamily 5 group A member 1) [NCBI Gene 2516] {aka AD4BP, ELP, FTZ1, FTZF1, POF7, SF-1}, Anxa2 (annexin A2) [NCBI Gene 56611] {aka ANX2}, POU5F1 (POU class 5 homeobox 1) [NCBI Gene 5460] {aka OCT3, OCT4, OCT4Borf1, OTF-3, OTF3, OTF4}, ANXA5 (annexin A5) [NCBI Gene 308] {aka ANX5, CPB-I, ENX2, HEL-S-7, PP4, RPRGL3}, CYP4V2 (cytochrome P450 family 4 subfamily V member 2) [NCBI Gene 285440] {aka BCD, CYP4AH1}, SSTR2 (somatostatin receptor 2) [NCBI Gene 6752] {aka SST2}, Igh-6 (immunoglobulin heavy chain 6) [NCBI Gene 299357] {aka IgM, Igh-1a, Igh6, RGD1359202}, Mir21 (microRNA 21) [NCBI Gene 100314000] {aka rno-mir-21}, ERBB2 (erb-b2 receptor tyrosine kinase 2) [NCBI Gene 2064] {aka CD340, HER-2, HER-2/neu, HER2, MLN 19, MLN-19}, CASP3 (caspase 3) [NCBI Gene 836] {aka CPP32, CPP32B, SCA-1}, SAA [NCBI Gene 6287], HEPHL1 (hephaestin like 1) [NCBI Gene 341208] {aka HJDD, ZP}, PAEP (progestagen associated endometrial protein) [NCBI Gene 5047] {aka GD, GdA, GdF, GdS, PAEG, PEP}, LRP1 (LDL receptor related protein 1) [NCBI Gene 4035] {aka A2MR, APOER, APR, CD91, DDH3, IGFBP-3R}, PGP (phosphoglycolate phosphatase) [NCBI Gene 283871] {aka AUM, G3PP, PGPase}, ANPEP (alanyl aminopeptidase, membrane) [NCBI Gene 290] {aka AP-M, AP-N, APN, CD13, GP150, LAP1}, Apob (apolipoprotein B) [NCBI Gene 238055] {aka Apo B-100, apob-100, apob-48}, TNF (tumor necrosis factor) [NCBI Gene 7124] {aka DIF, IMD127, TNF-alpha, TNFA, TNFSF2, TNLG1F}, AKR1A1 (aldo-keto reductase family 1 member A1) [NCBI Gene 10327] {aka ALDR1, ALR, ARM, DD3, HEL-S-6}, CCR7 (C-C motif chemokine receptor 7) [NCBI Gene 1236] {aka BLR2, CC-CKR-7, CCR-7, CD197, CDw197, CMKBR7}, SOX2 (SRY-box transcription factor 2) [NCBI Gene 6657] {aka ANOP3, MCOPS3}, Igf1 (insulin-like growth factor 1) [NCBI Gene 24482] {aka IGF}, CD44 (CD44 molecule (IN blood group)) [NCBI Gene 960] {aka CDW44, CSPG8, ECM-III, ECMR-III, H-CAM, HCELL}, CYP4F3 (cytochrome P450 family 4 subfamily F member 3) [NCBI Gene 4051] {aka CPF3, CYP4F, CYPIVF3, LTB4H}, IL1B (interleukin 1 beta) [NCBI Gene 3553] {aka IL-1, IL1-BETA, IL1F2, IL1beta}, NRP1 (neuropilin 1) [NCBI Gene 8829] {aka BDCA4, CD304, NP1, NRP, VEGF165R}, INS (insulin) [NCBI Gene 3630] {aka IDDM, IDDM1, IDDM2, ILPR, IRDN, MODY10}, P4HB (prolyl 4-hydroxylase subunit beta) [NCBI Gene 5034] {aka CLCRP1, DSI, ERBA2L, GIT, P4Hbeta, PDI}, Mmp2 (matrix metallopeptidase 2) [NCBI Gene 81686], PLAT (plasminogen activator, tissue type) [NCBI Gene 5327] {aka T-PA, TPA}, JUNB (JunB proto-oncogene, AP-1 transcription factor subunit) [NCBI Gene 3726] {aka AP-1}, Nrp1 (neuropilin 1) [NCBI Gene 246331] {aka Nrp}, IFNA1 (interferon alpha 1) [NCBI Gene 3439] {aka IFL, IFN, IFN-ALPHA, IFN-alphaD, IFNA13, IFNA@}, Gnrh1 (gonadotropin releasing hormone 1) [NCBI Gene 14714] {aka Gnrh, Gnrh2, LHRH, Lhrh1, Lnrh, hpg}, IFNG (interferon gamma) [NCBI Gene 3458] {aka IFG, IFI, IMD69}, EPCAM (epithelial cell adhesion molecule) [NCBI Gene 4072] {aka Ber-Ep4, BerEp4, DIAR5, EGP-2, EGP314, EGP40}, EPO (erythropoietin) [NCBI Gene 2056] {aka DBAL, ECYT5, EP, MVCD2}, IFNB1 (interferon beta 1) [NCBI Gene 3456] {aka IFB, IFF, IFN-beta, IFNB}, MTOR (mechanistic target of rapamycin kinase) [NCBI Gene 2475] {aka FRAP, FRAP1, FRAP2, RAFT1, RAPT1, SKS}, LYZ (lysozyme) [NCBI Gene 4069] {aka AMYLD5, LYZF1, LZM}, SLC17A5 (solute carrier family 17 member 5) [NCBI Gene 26503] {aka AST, ISSD, NSD, SD, SIALIN, SIASD}, TAT (tyrosine aminotransferase) [NCBI Gene 6898], CXCL10 (C-X-C motif chemokine ligand 10) [NCBI Gene 3627] {aka C7, IFI10, INP10, IP-10, SCYB10, crg-2}, CD69 (CD69 molecule) [NCBI Gene 969] {aka AIM, BL-AC/P26, CLEC2C, EA1, GP32/28, MLR-3}, CEND1 (cell cycle exit and neuronal differentiation 1) [NCBI Gene 51286] {aka BM88}, IL4R (interleukin 4 receptor) [NCBI Gene 3566] {aka CD124, IL-4RA, IL4RA}, Tnfsf10 (TNF superfamily member 10) [NCBI Gene 246775] {aka Tnlg6a, Trail}, COPA (coat protein complex I subunit alpha) [NCBI Gene 1314] {aka AIAISD, AIAISD1, AILJK, HEP-COP, alpha-COP}, Il1r1 (interleukin 1 receptor, type I) [NCBI Gene 16177] {aka CD121a, CD121b, IL-1R-1, IL-1R-alpha, IL-1R1, IL-1RT-1}, ALB (albumin) [NCBI Gene 213] {aka FDAHT, HSA, PRO0883, PRO0903, PRO1341}, Alb (albumin) [NCBI Gene 11657] {aka Alb-1, Alb1, BCL001, BCL002, BPL001}, NANOG (Nanog homeobox) [NCBI Gene 79923]
- **Diseases:** leukocytopenia (MESH:D007970), interstitial nephritis (MESH:D009395), nausea (MESH:D009325), hypoxia (MESH:D000860), anaphylaxis (MESH:D000707), hemolysis (MESH:D006461), cardiotoxicity (MESH:D066126), hyperthermia (MESH:D005334), granulocytopenia (MESH:D000380), PDAC (MESH:C537768), inflammation (MESH:D007249), injury to (MESH:D014947), melanoma (MESH:D008545), glioma (MESH:D005910), age-related macular degeneration (MESH:D008268), acute pancreatitis (MESH:D010195), edema (MESH:D004487), PCL (MESH:D008209), cancer (MESH:D009369), Hepatic toxicity (MESH:D056486), Allergic reaction (MESH:D004342), type 1 diabetes (MESH:D003922), lymphoma (MESH:D008223), drug (MESH:D000081015), breast cancer (MESH:D001943), kidney disease (MESH:D007674), glioblastoma (MESH:D005909), infectious disease (MESH:D003141), neutropenia (MESH:D009503), ABC (MESH:D006402), acromegaly (MESH:D000172), PDC (MESH:C537181), anemia (MESH:D000740), GIST (MESH:D046152), lung-metastasis (MESH:D009362), Cytotoxicity (MESH:D064420), weight loss (MESH:D015431), arthralgia (MESH:D018771), infection (MESH:D007239), thrombocytopenia (MESH:D013921), cholestatic DILI (MESH:D002779), ALL (MESH:D054198)
- **Chemicals:** panobinostat (MESH:D000077767), ribavirin (MESH:D012254), vanillin (MESH:C100058), Polypeptides (MESH:D010455), imatinib (MESH:D000068877), penicillin G (MESH:D010400), catechol (MESH:C034221), retinol (MESH:D014801), bortezomib (MESH:D000069286), levofloxacin (MESH:D064704), retinoid (MESH:D012176), Water (MESH:D014867), sunitinib (MESH:D000077210), phospholipid (MESH:D010743), Angiopep-2 (MESH:C531860), Tyr (MESH:D014443), GMA (MESH:C007870), PBMA (MESH:C068872), Schiff bases (MESH:D012545), amide (MESH:D000577), hydroxypropyl-beta-cyclodextrin (MESH:D000073738), 17-AAG (MESH:C112765), tanshinone IIA (MESH:C021751), SB (MESH:D000965), hydrazone (MESH:D006835), Caelyx (MESH:C506643), carotene (MESH:D002338), mitoxantrone (MESH:D008942), cholesterol (MESH:D002784), nitric oxide (MESH:D009569), Asn (MESH:D001216), amoxicillin (MESH:D000658), ethanol (MESH:D000431), flutamide (MESH:D005485), Sulfobetaine (MESH:C483727), hyaluronan (MESH:D006820), ButOx (MESH:C017180), chloride (MESH:D002712), risperidone (MESH:D018967), glycine (MESH:D005998), hydroxyl (MESH:D017665), dihydropyridines (MESH:D004095), polydopamine (MESH:C568283), rotigotine (MESH:C047508), iron oxide (MESH:C000499), CAC (MESH:C055936), HPMC-AS (MESH:C048331), 177Lu-DOTA-TATE (MESH:C447941), adenine (MESH:D000225), gentamicin (MESH:D005839), SDS (MESH:D012967), Rh (MESH:D012238), topotecan (MESH:D019772), PEG4000 (MESH:C000595214), chitosan (MESH:D048271), DMG-PEG2000 (MESH:C000626005), P (MESH:D010758), phosphate (MESH:D010710), NR (MESH:C044808), TCEP (MESH:C080938)
- **Species:** Ovis aries (domestic sheep, species) [taxon 9940], Sus scrofa (pig, species) [taxon 9823], Human immunodeficiency virus 1 (no rank) [taxon 11676], Escherichia coli (E. coli, species) [taxon 562], Leiurus quinquestriatus (Egyptian scorpion, species) [taxon 6883], Leishmania infantum (species) [taxon 5671], Canis lupus familiaris (dog, subspecies) [taxon 9615], Klebsiella pneumoniae (species) [taxon 573], Plasmodium yoelii (species) [taxon 5861], Pseudomonas aeruginosa (species) [taxon 287], Mus musculus (house mouse, species) [taxon 10090], Cavia porcellus (domestic guinea pig, species) [taxon 10141], Cocos nucifera (coconut palm, species) [taxon 13894], Homo sapiens (human, species) [taxon 9606], Rattus norvegicus (brown rat, species) [taxon 10116]
- **Mutations:** G680R, D842V, 27  C at N
- **Cell lines:** CA20948 — Homo sapiens (Human), Congenital disorder of glycosylation type Ia, Finite cell line (CVCL_DB07), E0771 — Mus musculus (Mouse), Malignant neoplasms of the mouse mammary gland, Cancer cell line (CVCL_GR23), MCF-7 — Homo sapiens (Human), Invasive breast carcinoma of no special type, Cancer cell line (CVCL_0031), MIA PaCa-2 — Homo sapiens (Human), Pancreatic undifferentiated carcinoma, Cancer cell line (CVCL_0428), PC3DIPEDOx150 — Homo sapiens (Human), Tongue squamous cell carcinoma, Cancer cell line (CVCL_VJ37), HepG2 — Homo sapiens (Human), Hepatoblastoma, Cancer cell line (CVCL_0027), A549 — Homo sapiens (Human), Lung adenocarcinoma, Cancer cell line (CVCL_0023), 293T — Homo sapiens (Human), Transformed cell line (CVCL_0063), L929 — Mus musculus (Mouse), Spontaneously immortalized cell line (CVCL_AR58), HLB — Homo sapiens (Human), Transformed cell line (CVCL_LC11), TF-1 — Homo sapiens (Human), Erythroleukemia, Cancer cell line (CVCL_3608), fibroblasts — Mus musculus (Mouse), Spontaneously immortalized cell line (CVCL_0594), NCI-H69 — Homo sapiens (Human), Lung small cell carcinoma, Cancer cell line (CVCL_1579), PC-3 — Homo sapiens (Human), Prostate carcinoma, Cancer cell line (CVCL_0035), HeLa — Homo sapiens (Human), Human papillomavirus-related endocervical adenocarcinoma, Cancer cell line (CVCL_0030), SKOV-3 — Homo sapiens (Human), Ovarian serous cystadenocarcinoma, Cancer cell line (CVCL_0532), B16 — Mus musculus (Mouse), Hybridoma (CVCL_U043), HT-29 — Homo sapiens (Human), Colon adenocarcinoma, Cancer cell line (CVCL_0320), ADR — Homo sapiens (Human), Neuroblastoma, Cancer cell line (CVCL_V006), HT-1080 — Homo sapiens (Human), Fibrosarcoma, Cancer cell line (CVCL_0317), 4T1 — Mus musculus (Mouse), Malignant neoplasms of the mouse mammary gland, Cancer cell line (CVCL_0125), MDA-MB-231 — Homo sapiens (Human), Breast adenocarcinoma, Cancer cell line (CVCL_0062), mSiO2-dPG — Homo sapiens (Human), Colon carcinoma, Cancer cell line (CVCL_A628), SKBR3 — Homo sapiens (Human), Breast adenocarcinoma, Cancer cell line (CVCL_0033), THP-1 — Homo sapiens (Human), Childhood acute monocytic leukemia, Cancer cell line (CVCL_0006), J774A.1 — Mus musculus (Mouse), Mouse reticulum cell sarcoma, Cancer cell line (CVCL_0358), HEK293 — Homo sapiens (Human), Transformed cell line (CVCL_0045), PC3DIPEDOx90 — Homo sapiens (Human), Ovarian adenocarcinoma, Cancer cell line (CVCL_A8KK), HeLa-R — Homo sapiens (Human), Human papillomavirus-related endocervical adenocarcinoma, Cancer cell line (CVCL_9493)

## Full text

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## Figures

25 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12943207/full.md

## References

89 references — full list in the complete paper: https://tomesphere.com/paper/PMC12943207/full.md

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Source: https://tomesphere.com/paper/PMC12943207