{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T13:31:18Z","timestamp":1787923878036,"version":"build-2784847793"},"reference-count":51,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T00:00:00Z","timestamp":1787875200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100013276","name":"Interreg","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100013276","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Bioeng. Biotechnol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Natural polysaccharide\u2010based hydrogels are promising materials for extrusion\u2010based 3D bioprinting, although achieving an adequate balance between cellular response, extrudability and shape fidelity remains challenging.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>In this study, hydrogel formulations based on konjac glucomannan, agar and citrus pectin were developed and evaluated under an initial safe(r)\u2010by\u2010design approach for future extrusion\u2010based bioprinting applications. The materials were combined at different concentrations to assess their rheological behaviour, direct\u2010contact cellular response and printability-related performance.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Konjac glucomannan contributed to water retention and viscosity modulation, agar provided thermal gelation and structural reinforcement, and citrus pectin modified flow behaviour and polymer\u2010network interactions. Rheological analysis showed shear\u2010thinning flow for all formulations, while the four selected formulations showed G\u2032 values higher than G\u2033 throughout the 0.1\u201320 Hz frequency range and re-established G\u2032 &amp;gt; G\u2033 after large\u2010amplitude deformation. Increasing agar concentration generally increased stiffness and extrusion resistance, whereas pectin reduced resistance to flow and was associated with lower mean relative pore\u2010area values in the analysed grids. The direct\u2010contact MTS assay was interpreted as a measure of apparent metabolic activity, rather than as an absolute quantification of viable cell number, due to the possible influence of hydrogel\u2010assay interactions. Printability\u2010related assays showed that the pectin\u2010free formulations, particularly 2K0.1A and 2K0.2A, exhibited higher mean relative pore-area values in the analysed grids, whereas the pectin-containing formulations showed lower extrusion resistance and improved flowability but lower mean relative pore-area values.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>Overall, 2K0.1A showed the most balanced behaviour among the evaluated formulations when considering extrusion resistance, collapse performance, relative self-supporting index and the descriptive pore-area results. These results support the potential of konjac-agar-pectin hydrogels as printable natural-material platforms, while highlighting the need for further optimisation and validation under cell-laden and tissue-specific conditions.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fbioe.2026.1900478","type":"journal-article","created":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T12:52:19Z","timestamp":1787921539000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Initial safe(r)-by-design assessment of printable konjac-agar-pectin hydrogels for future extrusion-based bioprinting applications"],"prefix":"10.3389","volume":"14","author":[{"given":"Laura","family":"Mendoza-Cerezo","sequence":"first","affiliation":[{"name":"Departamento de Expresi\u00f3n Gr\u00e1fica, Escuela de Ingenier\u00edas Industriales, Universidad de Extremadura","place":["Badajoz, Spain"]},{"name":"Departamento de Bioqu\u00edmica, Biolog\u00eda Molecular y Gen\u00e9tica, Facultad de Ciencias, Universidad de Extremadura","place":["Badajoz, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francisco","family":"I\u00f1esta\u2010Vaquera","sequence":"additional","affiliation":[{"name":"Departamento de Bioqu\u00edmica, Biolog\u00eda Molecular y Gen\u00e9tica, Facultad de Ciencias, Universidad de Extremadura","place":["Badajoz, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"Mac\u00edas-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Departamento de Expresi\u00f3n Gr\u00e1fica, Escuela de Ingenier\u00edas Industriales, Universidad de Extremadura","place":["Badajoz, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alfonso C.","family":"Marcos-Romero","sequence":"additional","affiliation":[{"name":"Departamento de Expresi\u00f3n Gr\u00e1fica, Escuela de Ingenier\u00edas Industriales, Universidad de Extremadura","place":["Badajoz, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jes\u00fas M.","family":"Rodr\u00edguez-Rego","sequence":"additional","affiliation":[{"name":"Departamento de Expresi\u00f3n Gr\u00e1fica, Escuela de Ingenier\u00edas Industriales, Universidad de Extremadura","place":["Badajoz, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,28]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"99","DOI":"10.3390\/polym12010099","article-title":"Xanthan Gum\u2013Konjac Glucomannan blend hydrogel for wound healing","volume":"12","author":"Alves","year":"2020","journal-title":"Polymers"},{"key":"B2","first-page":"359","article-title":"Analysis of viscosity behaviour of shear-thinning hydrogels in 3d-printing nozzles","author":"Ardaneh","year":"2024"},{"key":"B3","first-page":"179","article-title":"Electrophoresis and dielectrophoresis, in particle separation techniques","volume-title":"Handbooks in Separation Science","author":"Barasinski","year":"2022"},{"key":"B4","doi-asserted-by":"publisher","first-page":"630","DOI":"10.3390\/ijms24010630","article-title":"Preparation of hydrogels based on modified pectins by tuning their properties for anti-glioma therapy","volume":"24","author":"Belousov","year":"2022","journal-title":"Int. J. Mol. Sci."},{"key":"B5","doi-asserted-by":"publisher","first-page":"101169","DOI":"10.1016\/j.mtla.2021.101169","article-title":"Investigation of rheology, printability, and biocompatibility of N,O-Carboxymethyl chitosan and agarose bioinks for 3D bioprinting of neuron cells","volume":"18","author":"Butler","year":"2021","journal-title":"Materialia"},{"key":"B6","doi-asserted-by":"publisher","first-page":"2605","DOI":"10.1200\/JCO.2019.37.15_suppl.2605","article-title":"2D and 3D thermally bioprinted human MCF-7 breast cancer cells: a promising model for drug discovery","volume":"37","author":"Campbell","year":"2019","journal-title":"J. Clin. Oncol."},{"key":"B7","doi-asserted-by":"publisher","first-page":"025002","DOI":"10.1088\/1758-5090\/ac48e4","article-title":"3D bioprinted tumor model with extracellular matrix enhanced bioinks for nanoparticle evaluation","volume":"14","author":"Chen","year":"2022","journal-title":"Biofabrication"},{"key":"B8","doi-asserted-by":"publisher","first-page":"1097","DOI":"10.1089\/ten.tec.2011.0260","article-title":"MCF-7 cells as a three-dimensional model for the study of human breast cancer","volume":"17","author":"do Amaral","year":"2011","journal-title":"Tissue Eng. Part C Methods"},{"key":"B9","doi-asserted-by":"publisher","first-page":"1642","DOI":"10.1016\/j.ijbiomac.2022.10.082","article-title":"Rheological insight of polysaccharide\/protein based hydrogels in recent food and biomedical fields: a review","volume":"222","author":"Fan","year":"2022","journal-title":"Int. J. Biol. Macromol."},{"key":"B10","doi-asserted-by":"publisher","first-page":"033001","DOI":"10.1088\/1758-5090\/abe7ab","article-title":"Printability in extrusion bioprinting","volume":"13","author":"Fu","year":"2021","journal-title":"Biofabrication"},{"key":"B11","doi-asserted-by":"publisher","first-page":"13750","DOI":"10.1039\/D5TB00737B","article-title":"A comprehensive protocol for hydrogel-based bioink design: balancing printability, stability, and biocompatibility","volume":"13","author":"Geevarghese","year":"2025","journal-title":"J. Mat. Chem. B"},{"key":"B12","doi-asserted-by":"publisher","first-page":"3817","DOI":"10.1080\/10408398.2020.1870034","article-title":"Recent advances in the structure, synthesis, and applications of natural polymeric hydrogels","volume":"62","author":"Gul","year":"2022","journal-title":"Crit. Rev. Food Sci. Nutr."},{"key":"B13","doi-asserted-by":"publisher","first-page":"373","DOI":"10.1016\/j.eurpolymj.2017.01.027","article-title":"A review of the designs and prominent biomedical advances of natural and synthetic hydrogel formulations","volume":"88","author":"Gyles","year":"2017","journal-title":"Eur. Polym. J."},{"key":"B14","doi-asserted-by":"publisher","first-page":"106297","DOI":"10.1016\/j.polymertesting.2019.106297","article-title":"Collagen and chitosan blends for 3D bioprinting: a rheological and printability approach","volume":"82","author":"Heidenreich","year":"2020","journal-title":"Polym. Test."},{"key":"B15","volume-title":"Estructura y propiedades viscoel\u00e1sticas de nuevos hidrogeles basados en polialcohol vin\u00edlico","author":"Hern\u00e1ndez Velasco","year":"2004"},{"key":"B16","doi-asserted-by":"publisher","first-page":"127608","DOI":"10.1016\/j.colsurfa.2021.127608","article-title":"Modulating nanocellulose hydrogels and cryogels strength by crosslinking and blending","volume":"630","author":"Hossain","year":"2021","journal-title":"Colloids Surf. Physicochem. Eng. Asp."},{"key":"B17","doi-asserted-by":"publisher","first-page":"136272","DOI":"10.1016\/j.foodchem.2023.136272","article-title":"Dipeptide-polysaccharides hydrogels through co-assembly","volume":"422","author":"Hu","year":"2023","journal-title":"Food Chem."},{"key":"B18","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1007\/s10126-017-9782-4","article-title":"Integration of bacterial expansin on agarolytic complexes to enhance the degrading activity of red algae by control of gelling properties","volume":"20","author":"Jeong","year":"2018","journal-title":"Mar. Biotechnol."},{"key":"B19","doi-asserted-by":"publisher","first-page":"045006","DOI":"10.1088\/1758-5090\/ab0631","article-title":"Printability of pulp derived crystal, fibril and blend nanocellulose-alginate bioinks for extrusion 3D bioprinting","volume":"11","author":"Jessop","year":"2019","journal-title":"Biofabrication"},{"key":"B20","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1016\/j.ijbiomac.2019.12.012","article-title":"Design and evaluation of Konjac glucomannan-based bioactive interpenetrating network (IPN) scaffolds for engineering vascularized bone tissues","volume":"143","author":"Kanniyappan","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"B21","doi-asserted-by":"publisher","first-page":"660","DOI":"10.18063\/ijb.v9i2.660","article-title":"Development of an alginate-gelatin bioink enhancing osteogenic differentiation by gelatin release","volume":"9","author":"Kim","year":"2023","journal-title":"Int. J. Bioprinting"},{"key":"B22","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1007\/978-94-011-3610-5_13","article-title":"Chemical structure and physico-chemical properties of agar","volume-title":"International Workshop on Gelidium","author":"Lahaye","year":"1991"},{"key":"B23","doi-asserted-by":"publisher","first-page":"608","DOI":"10.1016\/j.celrep.2018.12.090","article-title":"Modeling Tumor phenotypes in vitro with three-dimensional bioprinting","volume":"26","author":"Langer","year":"2019","journal-title":"Cell Rep."},{"key":"B24","doi-asserted-by":"publisher","first-page":"2121","DOI":"10.1016\/j.ijbiomac.2021.05.196","article-title":"Preparation and characterization of konjac glucomannan and gum Arabic composite gel","volume":"183","author":"Li","year":"2021","journal-title":"Int. J. Biol. Macromol."},{"key":"B25","doi-asserted-by":"publisher","first-page":"134985","DOI":"10.1016\/j.ijbiomac.2024.134985","article-title":"Improving the gel properties of Ficus pumila Linn. Pectin by incorporating deacetylated konjac glucomannan","volume":"278","author":"Luo","year":"2024","journal-title":"Int. J. Biol. Macromol."},{"key":"B26","doi-asserted-by":"publisher","first-page":"618","DOI":"10.1016\/j.pnsc.2020.09.015","article-title":"Recent advances and challenges in materials for 3D bioprinting","volume":"30","author":"Mao","year":"2020","journal-title":"Prog. Nat. Sci. Mat. Int."},{"key":"B27","doi-asserted-by":"publisher","first-page":"112661","DOI":"10.1016\/j.jfoodeng.2025.112661","article-title":"Development and characterization of konjac glucomannan\u2013agar hybrid hydrogels for peptide adsorption from casein hydrolysate","volume":"401","author":"Min","year":"2025","journal-title":"J. Food Eng."},{"key":"B28","doi-asserted-by":"publisher","first-page":"477","DOI":"10.1016\/j.cherd.2023.02.042","article-title":"The influence of pregelatinized starch on the rheology of a gellan gum-collagen IPN hydrogel for 3D bioprinting","volume":"192","author":"Ng","year":"2023","journal-title":"Chem. Eng. Res. Des."},{"key":"B29","first-page":"1151","article-title":"Agar-agar extraction, structural properties and applications: a review","volume":"11","author":"Pandya","year":"2022","journal-title":"Pharma Innov. J."},{"key":"B30","doi-asserted-by":"publisher","first-page":"044107","DOI":"10.1088\/1758-5090\/aa8dd8","article-title":"Proposal to assess printability of bioinks for extrusion-based bioprinting and evaluation of rheological properties governing bioprintability","volume":"9","author":"Paxton","year":"2017","journal-title":"Biofabrication"},{"key":"B31","doi-asserted-by":"publisher","first-page":"708","DOI":"10.3390\/gels8110708","article-title":"Enrichment of Agar Gel with antioxidant pectin from fireweed: mechanical and rheological properties, simulated digestibility, and oral processing","volume":"8","author":"Popov","year":"2022","journal-title":"Gels"},{"key":"B32","doi-asserted-by":"publisher","first-page":"118879","DOI":"10.1016\/j.carbpol.2021.118879","article-title":"Polyvinyl alcohol inclusion can optimize the sol-gel, mechanical and hydrophobic features of agar\/konjac glucomannan system","volume":"277","author":"Qiao","year":"2022","journal-title":"Carbohydr. Polym."},{"key":"B33","doi-asserted-by":"publisher","first-page":"108365","DOI":"10.1016\/j.foodhyd.2022.108365","article-title":"Zein inclusion changes the rheological, hydrophobic and mechanical properties of agar\/konjac glucomannan based system","volume":"137","author":"Qiao","year":"2023","journal-title":"Food Hydrocoll."},{"key":"B34","doi-asserted-by":"publisher","first-page":"e05859","DOI":"10.1016\/j.heliyon.2020.e05859","article-title":"Rheological and mechanical properties of edible gel materials for 3D food printing technology","volume":"6","author":"Rahman","year":"2020","journal-title":"Heliyon"},{"key":"B35","doi-asserted-by":"publisher","first-page":"e00116","DOI":"10.1016\/j.bprint.2020.e00116","article-title":"Extrusion bioprinting: recent progress, challenges, and future opportunities","volume":"21","author":"Ramesh","year":"2021","journal-title":"Bioprinting"},{"key":"B36","doi-asserted-by":"publisher","first-page":"1081065","DOI":"10.3389\/fbiom.2023.1081065","article-title":"Design of a novel bioink suitable for the 3D printing of lymphoid cells","volume":"2","author":"Ribezzi","year":"2023","journal-title":"Front. Biomater. Sci."},{"key":"B37","doi-asserted-by":"publisher","first-page":"108353","DOI":"10.1016\/j.foodhyd.2022.108353","article-title":"Mixed gels based on low acyl gellan and citrus pectin: a linear viscoelastic analysis","volume":"137","author":"Rivera-Hern\u00e1ndez","year":"2023","journal-title":"Food Hydrocoll."},{"key":"B38","doi-asserted-by":"publisher","first-page":"3638","DOI":"10.1021\/acsbiomaterials.0c00260","article-title":"Fabrication of aligned biomimetic Gellan gum-chitosan microstructures through 3D printed microfluidic channels and multiple in situ cross-linking mechanisms","volume":"6","author":"Robinson","year":"2020","journal-title":"ACS Biomater. Sci. Eng."},{"key":"B39","doi-asserted-by":"publisher","first-page":"732","DOI":"10.3390\/gels9090732","article-title":"Pectin hydrogels: Gel-forming behaviors, mechanisms, and food applications","volume":"9","author":"Said","year":"2023","journal-title":"Gels"},{"key":"B40","doi-asserted-by":"publisher","first-page":"2320","DOI":"10.3390\/cancers12082320","article-title":"Comparison of hydrogels for the development of well-defined 3D cancer models of breast cancer and melanoma","volume":"12","author":"Schmid","year":"2020","journal-title":"Cancers"},{"key":"B41","doi-asserted-by":"publisher","first-page":"127678","DOI":"10.1016\/j.molliq.2025.127678","article-title":"Hydrogels from agar and citrus pectin for cleaning cultural heritage objects","volume":"431","author":"Spitz-Argolo","year":"2025","journal-title":"J. Mol. Liq."},{"key":"B42","doi-asserted-by":"publisher","first-page":"255","DOI":"10.3390\/gels7040255","article-title":"Relationship between structure and rheology of hydrogels for various applications","volume":"7","author":"Stojkov","year":"2021","journal-title":"Gels"},{"key":"B43","doi-asserted-by":"publisher","first-page":"e00112","DOI":"10.1016\/j.bprint.2020.e00112","article-title":"Image analysis as PAT-Tool for use in extrusion-based bioprinting","volume":"21","author":"Strau\u00df","year":"2021","journal-title":"Bioprinting"},{"key":"B44","doi-asserted-by":"publisher","first-page":"1852","DOI":"10.3390\/polym15081852","article-title":"Review of Konjac Glucomannan structure, properties, gelation mechanism, and application in medical biology","volume":"15","author":"Sun","year":"2023","journal-title":"Polymers"},{"key":"B45","doi-asserted-by":"publisher","first-page":"3156","DOI":"10.1016\/j.ijbiomac.2020.09.251","article-title":"Hydrogels based on low-methoxyl amidated citrus pectin and flaxseed gum formulated with tripeptide glycyl-l-histidyl-l-lysine improve the healing of experimental cutting wounds in rats","volume":"165","author":"Synytsya","year":"2020","journal-title":"Int. J. Biol. Macromol."},{"key":"B46","doi-asserted-by":"publisher","first-page":"23240","DOI":"10.1038\/s41598-024-73774-1","article-title":"3D bioprinting of fish skin-based gelatin methacryloyl (GelMA) bio-ink for use as a potential skin substitute","volume":"14","author":"Tanadchangsaeng","year":"2024","journal-title":"Sci. Rep."},{"key":"B47","doi-asserted-by":"publisher","first-page":"107469","DOI":"10.1016\/j.foodhyd.2021.107469","article-title":"Insights into the formation of konjac glucomannan gel induced by ethanol equilibration","volume":"126","author":"Tong","year":"2022","journal-title":"Food Hydrocoll."},{"key":"B48","doi-asserted-by":"publisher","first-page":"140380","DOI":"10.1016\/j.ijbiomac.2025.140380","article-title":"Development of high-strength, 3D-printable, and biocompatible gelatin\/\u03ba-carrageenan dual-network hydrogels for wound healing","volume":"301","author":"Wang","year":"2025","journal-title":"Int. J. Biol. Macromol."},{"key":"B49","doi-asserted-by":"publisher","first-page":"126355","DOI":"10.1016\/j.ijbiomac.2023.126355","article-title":"Konjac glucomannan\/pectin\/Ca-Mg hydrogel with self-releasing alkalinity to recover phosphate in aqueous solution","volume":"252","author":"Wu","year":"2023","journal-title":"Int. J. Biol. Macromol."},{"key":"B50","doi-asserted-by":"publisher","first-page":"2250","DOI":"10.3390\/ijms18112250","article-title":"A review on Konjac Glucomannan gels: microstructure and application","volume":"18","author":"Yang","year":"2017","journal-title":"Int. J. Mol. Sci."},{"key":"B51","doi-asserted-by":"publisher","first-page":"3807","DOI":"10.1039\/C8SM02277A","article-title":"Cohesive and adhesive properties of crosslinked semiflexible biopolymer networks","volume":"15","author":"Zhang","year":"2019","journal-title":"Soft Matter"}],"container-title":["Frontiers in Bioengineering and Biotechnology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2026.1900478\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T12:52:21Z","timestamp":1787921541000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2026.1900478\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,28]]},"references-count":51,"alternative-id":["10.3389\/fbioe.2026.1900478"],"URL":"https:\/\/doi.org\/10.3389\/fbioe.2026.1900478","relation":{},"ISSN":["2296-4185"],"issn-type":[{"value":"2296-4185","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,28]]},"article-number":"1900478"}}