Mineralization of gellan gum hydrogels with calcium and magnesium carbonates by alternate soaking in solutions of calcium/magnesium and carbonate ion solutions

Abstract

Mineralization of hydrogels is desirable prior to applications in bone regeneration. CaCO is a widely used bone regeneration material, and Mg, when used as a component of calcium phosphate biomaterials, has promoted bone-forming cell adhesion and proliferation and bone regeneration. In this study, gellan gum hydrogels were mineralized with carbonates containing different amounts of calcium (Ca) and magnesium (Mg) by alternate soaking in, firstly, a calcium and/or magnesium ion solution and, secondly, a carbonate ion solution. This alternate soaking cycle was repeated five times. Five different calcium and/or magnesium ion solutions, containing different molar ratios of Ca to Mg ranging from Mg free to Ca free were compared. Carbonate mineral formed in all sample groups subjected to the alternate soaking cycle. Ca : Mg elemental ratio in the mineral formed was higher than in the respective mineralizing solution. Mineral formed in the absence of Mg was predominantly CaCO in the form of a mixture of calcite and vaterite. Increasing the Mg content in the mineral formed led to the formation of magnesian calcite and decreased the total amount of the mineral formed and its crystallinity. Hydrogel mineralization and increasing Mg content in mineral formed did not obviously improve proliferation of MC3T3-E1 osteoblast-like cells or differentiation after 7 days.

Nanofibrillar Hydrogels by Temperature Driven Self‐Assembly: New Structures for Cell Growth and Their Biological and Medical Implications

“…[ 56 ] Together with the in situ gelation ability of GG hydrogels, those properties have been supporting their exploitation for different regenerative medicine applications. [ 57 ] Either acellular or cellular strategies were successfully proposed for drug delivery, [ 58 ] bone, [ 59–61 ] and nerves [ 62 ] repair. However, cell adhesion to commonly assembled GG is practically absent.…”

“…[ 56,63,64 ] Cell adhesion features to GG hydrogels have been provided only by the combination with gelatin, [ 65 ] GG modification with a GRGDS peptide [ 66 ] sequence and mineralization with calcium and magnesium carbonates. [ 60,67 ] Also, there are different approaches for enhancing cell adhesion properties, including hybrid materials, [ 28,29 ] where inorganic components (often nanoparticles) directly stimulate the cell growth by incorporation of such biomolecules as alkaline phosphatase. [ 68,69 ] Nanoparticles have been recognized for affecting the polymeric structures, [ 70,71 ] so controlled nanoparticle adsorption [ 72 ] at biointerfaces has been shown, on the one hand, to serve as activation centers, [ 73 ] while, on the other hand, to promote cell adhesion.…”

Marine-Inspired Enzymatic Mineralization of Dairy-Derived Whey Protein Isolate (WPI) Hydrogels for Bone Tissue Regeneration

“…Differences between the structures of WPI hydrogels and GG hydrogels may influence the type of mineral formed. The concentration of polymer in WPI hydrogels in this study (50% (w/v)) is much higher than in the GG hydrogels used in previous works (0.7% (w/v)) [10,14,15]. A higher concentration of polymer would lead to smaller pores in the polymer network.…”

“…During enzymatic mineralization of hydrogels with CaCO 3 , magnesium ions can be added to the mineralization medium which may lead to an increase in cell number [13,14]. In previous work, Gellan Gum (GG) hydrogels have been mineralized with CaCO 3 and/or calcium magnesium carbonate by incorporation of the enzyme urease into the hydrogel network followed by incubation in a solution containing the enzyme substrate, urea, and calcium and magnesium ions [14,15].…”

Advancement in the Biomedical Applications of the (Nano)gel Structures Based on Particular Polysaccharides

“…Gellan gum hydrogels allow as well for mineralized by incubation of alkaline phosphatase in mineralization media containing calcium and/or magnesium glycerophosphate for applications in bone regeneration . Mineral formation was confirmed by various techniques, Ca being incorporated into mineral to a greater extent than Mg, but samples with Mg incorporated into mineral, enhanced osteoblast attachment and proliferation.…”