title: Composites of gellan gum hydrogel enzymatically mineralized with calcium-zinc phosphate for bone regeneration with antibacterial activity.
abstract: Gellan gum hydrogels functionalized with alkaline phosphatase were enzymatically mineralized with phosphates in mineralization medium containing calcium (Ca) and zinc (Zn) to improve their suitability as biomaterials for bone regeneration. The aims of the study were to endow mineralized hydrogels with antibacterial activity by incorporation of Zn in the inorganic phase, and to investigate the effect of Zn incorporation on the amount and type of mineral formed, the compressive modulus of the mineralized hydrogels and on their ability to support adhesion and growth of MC3T3-E1 osteoblast-like cells. Mineralization medium contained glycerophosphate (0.05 m) and three different molar Ca:Zn ratios, 0.05:0, 0.04:0.01 and 0.025:0.025 (all mol/dm3), hereafter referred to as A, B and C, respectively. FTIR, SAED and TEM analysis revealed that incubation for 14 days caused the formation of predominantly amorphous mineral phases in sample groups A, B and C. The presence of Zn in sample groups B and C was associated with a drop in the amount of mineral formed and a smaller mineral deposit morphology, as observed by SEM. ICP-OES revealed that Zn was preferentially incorporated into mineral compared to Ca. Mechanical testing revealed a decrease in compressive modulus in sample group C. Sample groups B and C, but not A, showed antibacterial activity against biofilm-forming, methicillin-resistant Staphylococcus aureus. All sample groups supported cell growth. Zn incorporation increased the viable cell number. The highest values were seen on sample group C. In conclusion, the sample group containing the most Zn, i.e. group C, appears to be the most promising. Copyright © 2015 John Wiley & Sons, Ltd.
authors.affiliation: Polymer Chemistry and Biomaterials (PBM) Group, Department of Organic Chemistry, Ghent University, Belgium.
authors.forename: Timothy E L
authors.initials: TEL
authors.lastname: Douglas
authors.affiliation: Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Krakow, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Pilarz
authors.affiliation: Department of Experimental and Orofacial Medicine, Faculty of Dentistry, Philipps University, Marburg, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Lopez-Heredia
authors.affiliation: Laboratory of Pharmaceutical Microbiology, Ghent University, Belgium.
authors.forename: Gilles
authors.initials: G
authors.lastname: Brackman
authors.affiliation: Centre for Microsystems Technology (CMST), IMEC, and Ghent University, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: Schaubroeck
authors.affiliation: Department of Analytical Chemistry, Ghent University, Belgium.
authors.forename: Lieve
authors.initials: L
authors.lastname: Balcaen
authors.affiliation: Department of Materials Science and Engineering, Zwijnaarde, Belgium.
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Bliznuk
authors.affiliation: Polymer Chemistry and Biomaterials (PBM) Group, Department of Organic Chemistry, Ghent University, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Dubruel
authors.affiliation: Department of Experimental and Orofacial Medicine, Faculty of Dentistry, Philipps University, Marburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Knabe-Ducheyne
authors.affiliation: Department of Analytical Chemistry, Ghent University, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Vanhaecke
authors.affiliation: Laboratory of Pharmaceutical Microbiology, Ghent University, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Coenye
authors.affiliation: Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Krakow, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Pamula
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001861:Bone Regeneration / Q000187:drug effects*; D002113:Calcification, Physiologic / Q000187:drug effects*; D002130:Calcium Phosphates / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D020100:Hydrogels / Q000737:chemistry / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000254:growth & development*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010710:Phosphates / Q000737:chemistry / Q000494:pharmacology; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000494:pharmacology; D017967:Zinc Compounds / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D020100:Hydrogels; D010710:Phosphates; D011135:Polysaccharides, Bacterial; D017967:Zinc Compounds; C043952:zinc phosphate; C048288:gellan gum; C020243:calcium phosphate
keywords: antibacterial; composite; gellan gum; hydrogel; mineralization; zinc