title: Enrichment of enzymatically mineralized gellan gum hydrogels with phlorotannin-rich Ecklonia cava extract Seanol(®) to endow antibacterial properties and promote mineralization.
abstract: Hydrogels offer several advantages as biomaterials for bone regeneration, including ease of incorporation of soluble substances such as mineralization-promoting enzymes and antibacterial agents. Mineralization with calcium phosphate (CaP) increases bioactivity, while antibacterial activity reduces the risk of infection. Here, gellan gum (GG) hydrogels were enriched with alkaline phosphatase (ALP) and/or Seanol(®), a seaweed extract rich in phlorotannins (brown algae-derived polyphenols), to induce mineralization with CaP and increase antibacterial activity, respectively. The sample groups were unmineralized hydrogels, denoted as GG, GG/ALP, GG/Seanol and GG/Seanol/ALP, and hydrogels incubated in mineralization medium (0.1 M calcium glycerophosphate), denoted as GG/ALP_min, GG/Seanol_min and GG/Seanol/ALP_min. Seanol(®) enhanced mineralization with CaP and also increased compressive modulus. Seanol(®) and ALP interacted in a non-covalent manner. Release of Seanol(®) occurred in a burst phase and was impeded by ALP-mediated mineralization. Groups GG/Seanol and GG/ALP/Seanol exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus. GG/Seanol/ALP_min, but not GG/Seanol_min, retained some antibacterial activity. Eluates taken from groups GG/ALP_min, GG/Seanol_min and GG/ALP/Seanol_min displayed comparable cytotoxicity towards MG-63 osteoblast-like cells. These results suggest that enrichment of hydrogel biomaterials with phlorotannin-rich extracts is a promising strategy to increase mineralizability and antibacterial activity.
authors: Department of Organic Chemistry, Ghent University, Krijgslaan 281 S4, 9000 Gent, Belgium. Current address: Nano & Biophotonics group, Department Molecular Biotechology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors: Timothy E L
authors: TE
authors: Douglas
authors: Agnieszka
authors: A
authors: Dokupil
authors: Katarzyna
authors: K
authors: Reczyńska
authors: Gilles
authors: G
authors: Brackman
authors: Malgorzata
authors: M
authors: Krok-Borkowicz
authors: Julia K
authors: JK
authors: Keppler
authors: Mojca
authors: M
authors: Božič
authors: Pascal
authors: P
authors: Van Der Voort
authors: Krzysztof
authors: K
authors: Pietryga
authors: Sangram Keshari
authors: SK
authors: Samal
authors: Lieve
authors: L
authors: Balcaen
authors: Jan
authors: J
authors: van den Bulcke
authors: Joris
authors: J
authors: Van Acker
authors: Frank
authors: F
authors: Vanhaecke
authors: Karin
authors: K
authors: Schwarz
authors: Tom
authors: T
authors: Coenye
authors: Elżbieta
authors: E
authors: Pamuła
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000737:chemistry; D002460:Cell Line; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D055624:Methicillin-Resistant Staphylococcus aureus; D008826:Microbial Sensitivity Tests; D010006:Osteoblasts / Q000166:cytology; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D012624:Seaweed / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013634:Tannins / Q000737:chemistry*; D013818:Thermogravimetry
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D020100:Hydrogels; D011135:Polysaccharides, Bacterial; D013634:Tannins; C048288:gellan gum; D000469:Alkaline Phosphatase; C018392:tricalcium phosphate