A facile chemical cross-linking approach toward the fabrication of a sustainable porous ulvan scaffold

Abstract

Ulvans represent one of the most abundant marine-derived macromolecular sulfated polysaccharides accounting for numerous biological applications including in one of the fastest growing field of biomedical sciences. Tissue engineering based on biologically inspired and naturally derived polymers has been one of the prime focuses of regenerative medicine. The present investigation is intended to explore an ionic cross-linking approach at higher pH lead by the calcium ions for casting cell growth promoting scaffolds out of the raw ulvan. The characterization studies using attenuated total reflectance infrared spectroscopy represent specific absorptions at 2950, 980, and 600 cm−1, whereas the x-ray diffraction showed a total absence of major crystalline peaks presenting significant shift to an amorphous state. The 1H nuclear magnetic resonance study revealed functional group modifications in the backbone that might be potentially derived from calcium interactions with glucurorhamnose 3-sulfate and iduronorhamnose 3-sulfate. The atomic force microscopy together with field emission scanning electron microscopy and energy dispersive x-ray spectroscopy mapping revealed the resultant surface changes, whereas confocal microscopy z-stacking showed the cell proliferative activity as evident by the attainment of complete morphology. The combined chemical and biological response of the scaffold makes it a well suitable support for its cell culture and tissue engineering applications.

A Fully Integrated Biorefinery Process for the Valorization of Ulva fasciata into Different Green and Sustainable Value-Added Products

“…Similar observation was previously reported by Madany et al [11], who attributed that to the heavily branched structure of ulvan because of its indistinct backbone. Similar observation was also reported by Gajaria et al [70] and attributed that to the presence of junction zones, where cross-linking occurs. Moreover, Madany et al [11] reported that the ulvan's disordered conformational structure, which is caused by its heterogeneous chemical composition, accounts for the presence of amorphous regions.…”

“…Thus, the EDX analysis (Figure 11d) confirmed a sulfated polysaccharide with considerable protein content. The C-content in the extracted ulvan from the Egyptian Ulva fasciata in this study is lower than that reported for Indian Ulva fasciata [70], while the S content is higher. The protein content was calculated according to Alves et al [7] by multiplying the N-content by the factor 6.25, which revealed a protein content of approximately 19.06%.…”

“…A similar observation was reported for Ulva sp. ulvan [7], Indian Ulva fasciata ulvan [70], and Egyptian Ulva fasciata ulvan [11]. The minor peaks appear at (2θ) 9 • , 33 • , and 36 • (Figure 10c, blue arrows), were also reported for Egyptian Ulva fasciata ulvan [10].…”

Rosmarinic Acid and Ulvan from Terrestrial and Marine Sources in Anti-Microbial Bionanosystems and Biomaterials

“…The genus Ulva is adapted to various environmental conditions and could be wild-harvested or cultivated regarding ulvan extraction [41][42][43]. The extraction of the polymer occurs from many different locations around the world, including the species: U. rotundata [44], U. armoricana [44,45], U. rigida [46,47], U. clathrata [48], U. fasciata [49][50][51][52], U. intestinalis [53], U. ohnoi [54,55], U. lactuca [56][57][58], U. pertusa [59], and many others. Despite the dominance of red and brown seaweed production, the particular interest of Ulva is due to its fast growth rates and high ulvan carbohydrate content [40,60].…”

Bioactive Carbohydrate Polymers—Between Myth and Reality

“…Ulvan is sulfated polysaccharides extracted from the green algae with more diverse and complex structures, as well as biological activities less studied in compared to other sulfated polysaccharides [ 141 , 142 , 143 , 144 , 145 , 146 ]. Up to now, the diverse forms of carriers using ulvan including nanofibers, membranes, particles, hydrogels, and 3D porous structures have been developed ( Figure 2 ) for delivery drugs, for peptide/protein [ 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 ], for wound dressing or bone tissue engineering [ 147 , 148 , 149 , 150 , 151 , 155 , 156 , 157 , 158 , 159 ], for inhibiting HeLa [ 160 ] and glioblastoma cells [ 161 ], for proliferation splenocyte [ 162 ], for enhancing fibroblasts growth and angiogenesis [ 163 ], for enhancing differentiation PC-12 cells [ 164 ], and for proliferation mesenchymal stem cells [ 165 ].…”