Comparison of Extraction Methods for Sodium Alginate from Sargassum spp. for Biomedical Applications
Discipline: Biological Sciences
Subcategory: cell & molecular biology
Session: 2
Room: 1 - Hanover DE
Verónica Morales Quintana - University of Puerto Rico- Rio Piedras
Co-Author(s): Jeileen Luciano Rodríguez, University of Puerto Rico - Rio Piedras, Puerto Rico; Dr. Liz Díaz Vázquez, PhD., University of Puerto Rico – Río Piedras, Puerto Rico
Every year, Puerto Rico & neighboring countries receive high amounts of brown algae, from the Sargasso Sea, leading to detrimental shoreline accumulations of it. Both marine organisms & humans are negatively affected by it. The first may experience a reduction of sunlight, hypoxic water conditions, leachates & differing nesting conditions. While the latter, humans, experience a lower quality beach experience for example, due to foul gas liberation of decomposing seaweed that may lead to respiratory problems. These two perspectives combined can negatively affect the economy, tourism, & the local fishing industry. Thus, the removal of shoreline Sargassum spp. seaweed is imminent. One way to deviate the accumulations from our coasts and landfills is by repurposing the incoming algae and integrating it into our lives through material applications. Sargassum spp. are full of bioactive compounds such as polysaccharides that can be extracted and used from the food industry to the pharmaceutical industry. Particularly, for this research, we tested two extractions for sodium alginate (SA), an anti-inflammatory & antioxidant polysaccharide, from brown algae to determine which works best to eventually develop a hydrogel film. To do this, two extraction methods (A & B) were carried out, A through Accelerated Solvent Extraction & B being its benchtop counterpart. Their SA yields & quality were compared to assess which extraction was best. Method A had a 27.76 % yield of sodium alginate, a higher yield than Method B, 17.51%. The polysaccharide obtention was confirmed, using lab-grade SA as the control group, through Fourier Transformation Infrared (FTIR) & Elemental Energy-dispersive X-ray spectroscopy (EDS). FTIR allowed the identification of characteristic hydroxyl (3200-3500 cm-) & carboxylate groups (C=O stretching at 1596 cm-1 and 1406 cm-1, C-O stretching between 1024 – 977 cm-1) in the samples. The high thermal stability of the samples was shown through ThermoGravimetric Analysis (TGA). Regarding chlorophyll content, such was measured through a Soil Plant Analysis Development (SPAD) chlorophyll meter in which method A sodium alginate contained less chlorophyll than method B (3.9 SPAD versus 20.2 SPAD). SEM imaging was also done to analyze the alginate’s surface morphology. Since method A yielded a purer form of sodium alginate such was used to create a hydrophobic film (θ ≥ 90°). Future work includes additional characterization of sodium alginate from both extractions such as Raman spectroscopy & H-NMR analysis. Chlorophyll content quantification will be further studied along with the development of sodium alginate-based hydrogels and films for biomedical applications. By optimizing extractions from Sargassum spp., repurposing large littoral algae accumulations is achieved and allows the opportunity to obtain bioactive compounds for differing applications.
Funder Acknowledgement(s): NSF-CREST grant number HRD-1736093, MSEIP
Faculty Advisor: Dr. Liz Díaz Vázquez, PhD., liz.diaz2@upr.edu
Role: Undergraduate Research Assistant in Method Development & Characterization.