Thixotropic Red Microalgae Sulfated Polysaccharide-Peptide Composite Hydrogels as Scaffolds for Tissue Engineering

Abstract

Sulfated polysaccharides of red marine microalgae have recently gained much attention for biomedical applications due to their anti-inflammatory and antioxidant properties. However, their low mechanical properties limit their use in tissue engineering. Herein, to enhance the mechanical properties of the sulfated polysaccharide produced by the red marine microalga, Porphyridium sp. (PS), it was integrated with the fluorenylmethoxycarbonyl diphenylalanine (FmocFF) peptide hydrogelator. Transparent, stable hydrogels were formed when mixing the two components at a 1:1 ratio in three different concentrations. Electron microscopy showed that all hydrogels exhibited a nanofibrous structure, mimicking the extracellular matrix. Furthermore, the hydrogels were injectable, and tunable mechanical properties were obtained by changing the hydrogel concentration. The composite hydrogels allowed the sustained release of curcumin which was controlled by the change in the hydrogel concentration. Finally, the hydrogels supported MC3T3-E1 preosteoblasts viability and calcium deposition. The synergy between the sulfated polysaccharide, with its unique bioactivities, and FmocFF peptide, with its structural and mechanical properties, bears a promising potential for developing novel tunable scaffolds for tissue engineering that may allow cell differentiation into various lineages.

Ultrashort Cationic Peptide Fmoc-FFK as Hydrogel Building Block for Potential Biomedical Applications

“…The existence of a strong matrix, with a prominent viscoelastic nature, is also confirmed by the loss tangent (tanδ = G ′′ /G ′ ) value, which is 0.0526 for Fmoc-FFK/Fmoc-FF (1/20, w/w). This increase in the mechanical features, which are well documented for other multicomponent matrices, seems to be related to the ability of the Fmoc-FF building block to govern and drive the gelation process, reducing the probable electrostatic repulsion in pure Fmoc-FFK gels [46]. These electrostatic repulsions may justify the low mechanical response of Fmoc-FFK hydrogels, as evidenced by the lower G ′ values for multicomponent matrices with respect to the Fmoc-FF one (G ′ = 23,160 Pa at 1.0 wt% and 1.0 Hz; rheological characterization reported in Figure S10).…”

Physicochemical and Microstructural Characteristics of Sulfated Polysaccharide from Marine Microalga

“…In addition, it has been reported that these polysaccharides did not present cytotoxicity, and they can keep low glycemic levels and exert antioxidant activity simultaneously [7]. Microalgae sulfated polysaccharides have also gained attention for biomedical applications, such as developing tissue engineering scaffolds [8]. Microalgae sulfated polysaccharides have also been considered promising candidates in other sectors, such as the food industry and agriculture [9].…”