Materials and Methods: Cell viability and cytotoxicity of gelatin (Gel; 50 µg/µl), chitosan (Chi; 20 µg/µl), hydroxyapatite (HA; 50 µg/µl), nanohydroxyapatite (nHA; 10 µg/µl), three-calcium phosphate (TCP; 50 µg/µl) and strontium carbonate (Sr; 10 µg/µl) were evaluated on hADSCs via MTT assay. In vivo femoral drill-bone hole model was produced in rats that were either left untreated or treated with autograft, Gel, Chi, HA, nHA, TCP and Sr, respectively. The animals were euthanized after 30 days. Their bone holes were evaluated by gross-pathology, histopathology, SEM and radiography. Also, their dry matter, bone ash and mineral density were measured.
Results: Both the Gel and Chi showed cytotoxicity, while nHA had no role on cytotoxicity and cell-viability. All the HA, TCP and Sr significantly improved cell viability when compared to controls (P<0.05). Both the Gel and Chi had no role on osteoconduction and osteoinduction. Compared to HA, nHA showed superior role in increasing new bone formation, mineral density and ash (P<0.05). In contrast to HA and nHA, both the TCP and Sr showed superior morphological, radiographical and biochemical properties on bone healing (P<0.05). TCP and Sr showed the most effective osteoconduction and osteoinduction, respectively. In the Sr group, the most mature type of osteons formed.
Conclusion: Various biomaterials have different in vivo efficacy during bone regeneration. TCP was found to be the best material for osteoconduction and Sr for osteoinduction.
METHODS: Saccharide mapping or enzymatic profiling plays a role in quality control of polysaccharides. Whereby, in vitro and in vivo tests as well as toxicity level discriminating polysaccharides biological activities. Extraction and purification methods are performed in obtaining algal derived polysaccharides followed by chromatographic profiles of their active compounds, structural features, physicochemical properties, and reported biological activities.
RESULTS: Marine algae are capable of synthesizing Glycosaminoglycans (GAGs) and non-GAGs or GAG mimetics such as sulfated glycans. The cell walls of algae are rich in sulfated polysaccharides, including alginate, carrageenan, ulvan and fucoidan. These biopolymers are widely used algal-derived polysaccharides for biological and biomedical applications due to their biocompatibility and availability. They constitute biochemical compounds that have multi-functionalization, therapeutic potential and immunomodulatory abilities, making them promising bioactive products and biomaterials with a wide range of biomedical applications.
CONCLUSION: Algal-derived polysaccharides with clearly elucidated compositions/structures, identified cellular activities, as well as desirable physical properties have shown the potential that may create new opportunities. They could be maximally exploited to serve as therapeutic tools such as immunoregulatory agents or drug delivery vehicles. Hence, novel strategies could be applied to tailor multi-functionalization of the polysaccharides from algal species with vast biomedical application potentials.