{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T15:42:57Z","timestamp":1774366977546,"version":"3.50.1"},"reference-count":39,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2019,12,6]],"date-time":"2019-12-06T00:00:00Z","timestamp":1575590400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Novel cross-linked hydrogels were synthesized as potential materials for the development of smart biofertilizers. For this purpose, hydrogels were prepared using collagen hydrolysate recovered from tannery waste. The water-soluble polymer poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate) (P(SSNa-co-GMAx)) was among others used for the cross-linking reaction that combined hydrophilic nature with epoxide groups. The synthetic procedure was thoroughly investigated in order to ensure high percentage of epoxide groups in combination with water-soluble behavior. The copolymer did not show cytotoxicity against normal lung, skin fibroblasts, or nasal polyps fibroblasts. Through the present work, we also present the ability to control the properties of cross-linked hydrogels by altering copolymer\u2019s composition and cross-linking parameters (curing temperature and time). Hydrogels were then studied in terms of water-uptake capacity for a period up to six days. The techniques Proton Nuclear Magnetic Resonance (1H NMR), Thermogravimetric Analysis (TGA), Size Exclusion Chromatography (SEC), and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) were applied for the characterization of the synthesized copolymers and the cross-linked hydrogels. Three samples of biofertilizers based on collagen hydrolysate functionalized with P(SSNa-co-GMAx) and starch and having nutrients encapsulated (N, P, K) were prepared and characterized by physical\u2013chemical analysis and Energy Dispersive X-ray analysis-Scanning Electron Microscope (EDAX-SEM) in terms of microstructure. Preliminary tests for application as fertilizers were performed including the release degree of oxidable organic compounds.<\/jats:p>","DOI":"10.3390\/ma12244067","type":"journal-article","created":{"date-parts":[[2019,12,6]],"date-time":"2019-12-06T10:41:44Z","timestamp":1575628904000},"page":"4067","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["Modification of Collagen Derivatives with Water-Soluble Polymers for the Development of Cross-Linked Hydrogels for Controlled Release"],"prefix":"10.3390","volume":"12","author":[{"given":"Ioanna","family":"Tzoumani","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Patras, GR-265 04 Patras, Greece"},{"name":"Foundation for Research and Technology-Hellas (FORTH)\/Institute of Chemical Engineering Sciences (ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-265 04 Rio-Patras, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6604-1310","authenticated-orcid":false,"given":"Georgia Ch.","family":"Lainioti","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Patras, GR-265 04 Patras, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexios J.","family":"Aletras","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Patras, GR-265 04 Patras, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriel","family":"Zainescu","sequence":"additional","affiliation":[{"name":"National R &amp; D Institute for Textile and Leather-Division: Leather and Footwear Research Institute, 93 Ion Minulescu Str., 031215 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9787-194X","authenticated-orcid":false,"given":"Simina","family":"Stefan","sequence":"additional","affiliation":[{"name":"Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, 1-7 Polizu Str., 011061 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aurelia","family":"Meghea","sequence":"additional","affiliation":[{"name":"Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, 1-7 Polizu Str., 011061 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joannis K.","family":"Kallitsis","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Patras, GR-265 04 Patras, Greece"},{"name":"Foundation for Research and Technology-Hellas (FORTH)\/Institute of Chemical Engineering Sciences (ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-265 04 Rio-Patras, Greece"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,6]]},"reference":[{"key":"ref_1","first-page":"1401","article-title":"Obtaining of Biofertilisers Using Pelt Skin Wastes","volume":"67","author":"Stefan","year":"2016","journal-title":"Rev. Chim.-Bucharest."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1007\/s10311-017-0683-6","article-title":"Dust pollution and control with leather waste","volume":"16","author":"Dang","year":"2017","journal-title":"Envin. Chem. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"7277","DOI":"10.1007\/s11356-019-04226-x","article-title":"Recovery and utilization of collagen protein powder extracted from chromium leather scrap waste","volume":"26","author":"Dang","year":"2019","journal-title":"Environ. Sci. Pollut. 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