1. Vigata M, Meinert C, Hutmacher DW, Bock N. Hydrogels as drug delivery systems: A review of current characterization and evaluation techniques. Pharmaceutics 2020;12(12):1188. https://doi.org/10.3390/pharmaceutics12121188
2. Alrbaihat MR, Abu-Afifeh Q, Al-Zeidaneen FK. Chemically responsive hydrogels, properties, pharmaceuticals, and agricultural applications: A review. Al-bahir J Eng Pure Sci. 2023;2:101–110. https://doi.org/10.55810/2313-0083.1023
3. Kim B, Lim S. Removal of heavy metal ions from water by cross-linked carboxymethyl corn starch. Carbohydr Polym. 1999;39:217–223. https://doi.org/10.1016/S0144-8617(99)00011-9
4. Singha AS, Guleria A. Chemical modification of cellulosic biopolymer and its use in removal of heavy metal ions from wastewater. Int J Biol Macromol. 2014;67:409–417. https://doi.org/10.1016/j.ijbiomac.2014.03.046
5. Kesharwani P, Bisht A, Alexander A, Dave V, Sharma S. Biomedical applications of hydrogels in drug delivery system: An update. J Drug Deliv Sci Technol. 2021;66(2):102914. https://doi.org/10.1016/j.jddst.2021.102914
6. Cascone S, Lamberti G. Hydrogel-based commercial products for biomedical applications: A review. Int J Pharm. 2020;573:118803. https://doi.org/10.1016/j.ijpharm.2019.118803
7. Hamedi H, Moradi S, Hudson SM, Tonelli AE. Chitosan-based hydrogels and their applications for drug delivery in wound dressings: A review. Carbohydr Polym. 2018;199:445–460. https://doi.org/10.1016/j.carbpol.2018.06.114
8. Hong TT, Okabe H, Hidaka Y, Hara K. Removal of metal ions from aqueous solutions using carboxymethyl cellulose/sodium styrene sulfonate gels prepared by radiation grafting. Carbohydr Polym. 2017;157:335–343. https://doi.org/10.1016/j.carbpol.2016.09.049
9. Essawy HA, Ghazy MBM, Abd El-Hai F, Mohamed MF. Superabsorbent hydrogels via graft polymerization of acrylic acid from chitosan-cellulose hybrid and their potential in controlled release of soil nutrients. Int J Biol Macromol. 2016;89:144–151. https://doi.org/10.1016/j.ijbiomac.2016.04.071
10. Jeong D, Kim C, Kim Y, Jung S. Dual crosslinked carboxymethyl cellulose/polyacrylamide interpenetrating hydrogels with highly enhanced mechanical strength and superabsorbent properties. Eur Polym J. 2020;127:109586. https://doi.org/10.1016/j.eurpolymj.2020.109586
11. Wang H, Qu G, Liu X, He M, Yin C, Xu R. Hydrogel materials in agriculture: A review. J Environ Chem Eng. 2025;13(3),116385. https://doi.org/10.1016/j.jece.2025.116385
12. Yang J, Liu D, Song X, Zhao Y, Wang Y, Rao L, et al. Recent progress of cellulose-based hydrogel photocatalysts and their applications. Gels 2022;8(5):270. https://doi.org/10.3390/gels8050270
13. Ho TC, Chang CC, Chan HP, Chung TW, Shu CW, Chuang KP, et al. Hydrogels: Properties and applications in biomedicine. Molecules 2022;27:2902. https://doi.org/10.3390/molecules27092902
14. Zoller K, To D, Bernkop-Schnürch A. Biomedical applications of functional hydrogels: Innovative developments, relevant clinical trials, and advanced products. Biomaterials 2025;312:122718. https://doi.org/10.1016/j.biomaterials.2024.122718
15. Lee KZ, Jeon J, Jiang B, Subramani SV, Li J, Zhang F. Protein-based hydrogels and their biomedical applications. Molecules 2023;28:4988. https://doi.org/10.3390/molecules28134988
16. Viboonratanasri D, King DR, Okumura T, Terkawi MA, Katsuyama Y, Lama, et al. Porous and tough polyacrylamide/carboxymethyl cellulose gels chemically crosslinked via cryo-UV polymerization for sustained drug release. Gels 2025;11(6):453. https://doi.org/10.3390/gels11060453
17. Gounden V, Singh M. Hydrogels and wound healing: Current and future prospects. Gels 2024;10(1):43. https://doi.org/10.3390/gels10010043
18. Ishihara K, Shi X, Fukazawa K, Yamaoka T, Yao G, Wu JY. Biomimetic-engineered silicone hydrogel contact lens materials. ACS Appl Bio Mater. 2023;6(9):3600–3616. https://doi.org/10.1021/acsabm.3c00296
19. Choi H, Choi W-S, Jeong J-O. A review of advanced hydrogel applications for tissue engineering and drug delivery systems as biomaterials. Gels 2024;10(11):693. https://doi.org/10.3390/gels10110693
20. Khan MUA, Stojanović GM, Abdullah MFB, Dolatshahi-Pirouz A, Marei HE, Ashammakhi N, et al. Fundamental properties of smart hydrogels for tissue engineering applications: A review. Int J Biol Macromol. 2024;254(3):127882. https://doi.org/10.1016/j.ijbiomac.2023.127882
21. Kim H, Dutta SD, Randhawa A, Patil TV, Ganguly K, Acharya R, et al. Recent advances and biomedical application of 3D printed nanocellulose-based adhesive hydrogels: A review. Int J Biol Macromol. 2024;264(2):130732. https://doi.org/10.1016/j.ijbiomac.2024.130732
22. Agrawal A, Hussain CM. 3D-printed hydrogel for diverse applications: A review. Gels 2023;9(12):960. https://doi.org/10.3390/gels9120960
23. Wang X, Ji H, Gao L, Hao R, Shi Y, Yang J, et al. Wearable hydrogel-based health monitoring systems: A new paradigm for health monitoring? Chem Eng J. 2024;495:153382. https://doi.org/10.1016/j.cej.2024.153382
24. Mitura S, Sionkowska A, Jaiswal A. Biopolymers for hydrogels in cosmetics: A review. J Mater Sci Mater Med. 2020;31(6):50. https://doi.org/10.1007/s10856-020-06390-w
25. Kim JS, Park JH, Hwang J, Shim TS. Mechanically robust all-hydrogel supercapacitor having seamless interfaces among components by rapid phase transition of physical gels. Chem Eng J. 2023;472:144928. https://doi.org/10.1016/j.cej.2023.144928
26. Zhang K, Chen Z, Li J, Feng G, Xu C, Yang J, Li W. Conductive hydrogel materials for flexible supercapacitor electrodes. Crystals 2024;14(11):971. https://doi.org/10.3390/cryst14110971
27. Verma C, Negi P, Pathania D, Anjum S, Gupta B. Water management within tragacanth gum-g-poly(itaconic acid) hydrogels. Adv Mater Lett. 2019;10(10):711–714. https://doi.org/10.5185/amlett.2019.4090
28. Cao Q, Chen J, Wang M, Wang Z, Wang W, Shen Y, et al. Superabsorbent carboxymethyl cellulose-based hydrogel fabricated by liquid-metal-induced double crosslinking polymerization. Carbohydr Polym. 2024;331:121910. https://doi.org/10.1016/j.carbpol.2024.121910
29. Ford FM, Hall WP, inventors; J. Bancroft & Sons Co., assignee. Flameproofing of fibrous materials. United States patent US 2,482,756 A. 1949 Sep 27.
30. Emerson RW, inventor; Plasmine Corporation, assignee. Urea-containing sizing compositions. United States patent US 4,025,354 A. 1977 May 24.
31. Emerson RW, Shattuck JR, inventors; The Plasmine Corporation, assignee. Ammonia-containing sizing compositions. United States patent US 4,022,634 A. 1977 May 10.
32. Blount DH, inventor; Blount DH, assignee. Flame retardant compositions utilizing amino condensation compounds. United States patent US 5,854,309 A. 1998 Dec 29.
33. Blount DH, inventor; Blount DH, assignee. Flame retardant compositions utilizing amino condensation compounds. United States patent US 6,258,298 B1. 2001 Jul 10.
34. Blount DH, inventor; Blount DH, assignee. Flame retardant compositions utilizing amino condensation compounds. United States patent US 6,270,694 B1. 2001 Aug 7.
35. Blount DH, inventor; Blount DH, assignee. Flame retardant compositions utilizing amino condensation compounds. United States patent US 6,348,526 B1. 2002 Feb 19.
36. Sharzehee M. Application of oligomers with urea linkage as flame retardant and antibacterial materials in jute fabric. J Text Polym. 2020;8(2):23–32.
37. Fekete T, Borsa J, Takács E, Wojnárovits L. Synthesis of carboxymethylcellulose/starch superabsorbent hydrogels by gamma-irradiation. Chem Cent J. 2017;11(1):46. https://doi.org/10.1186/s13065-017-0273-5
38. El-Arnaouty MB, Abdel Ghaffar AM, Abdel Baky AAK, Shama SA. Radiation synthesis of hydrogels based on carboxymethyl cellulose and its application in removal of pollutants from wastewater. J Vinyl Addit Technol. 2017;23(1):E1–E7. https://doi.org/10.1002/vnl.21614
39. Aflatounian A, Sharzehee M, Mashroteh HA. Preparation of stable polyvinyl alcohol/polyurea hydrogel using oligomeric compounds containing urea-bonded. Results Mater. 2024;22:id.100564. https://doi.org/10.1016/j.rinma.2024.100564
40. Socrates G. Infrared and Raman characteristic group frequencies: tables and charts. 3rd ed. Chichester: John Wiley & Sons; 2004.
41. Piquero-Casals J, Morgado-Carrasco D, Granger C, Trullàs C, Jesús-Silva A, Krutmann J. Urea in dermatology: A review of its emollient, moisturizing, keratolytic, skin barrier enhancing and antimicrobial properties. Dermatol Ther (Heidelb). 2021;11:1905–11915. https://doi.org/10.1007/s13555-021-00611-y
42. Fang Y, Pei S, Zhuo L, Cheng P, Yuan H, Zhang L. Phosphorus and sulfur codoped carbon nitride nanosheets with enhanced photocatalytic antibacterial activity and promotion of wound healing. Appl Surf Sci. 2022;586:152761. https://doi.org/10.1016/j.apsusc.2022.152761