Basic Lipid Analysis of Microalgae Strain Pectinodesmus HM3, Formation of Phycosomes and in Vitro Drug Delivery

Abstract

Microalgal cells have been known to create a variety of substances like proteins, lipids, terepenoids, phenols, steroids, vitamins and minerals. Therefore the microalgae extracts are being purified or processed to produce multiple bioactive compounds or particles for use in the biotechnology industry. This study focuses on the lipid extract of microalgae strain Pectinodesmus HM3 and its general analysis. Lipid quantification was performed through gravimetric methods and qualification was done through FTIR and Gas Chromatography of the biodiesel created from the lipid extracted by ethanol and Folch solutions. The phospholipid or polar content of the lipid extract was used in the formation of algal liposomes or phycosomes. The phycosomes were characterized using various techniques. Curcumin loaded phycosomes were further used in drug delivery against brain cancer cell lines (u87). Results proved that the Pectinodesmus HM3 strain had a low lipid yield of 23% but the FAME content of the strain was 72%, this is a high biodiesel yield compared to majority microalgae strains present in the worlds algal database. The polar fatty acid content of the strain was found to be 20%. The unloaded phycosomes produced showed average size of 131 +/- 58 nm and average zeta potential of -34.1 +/- 4.74 mV. Negative charges on the phycosomes ensures that the particles will not form aggregates. The curcumin loaded phycosomes had an average size of 210 +/- 127 nm and zeta potential was an average of -48.6 +/- 5.28 mV. After drug loading, size of the phycosomes increased and zeta potential decreased as per previous studies on curcumin loading. Encapsulation efficiency of the phycosomes was 75%. Scanning electron microscopy images indicated dispersed and spherical phycosomes. Hemolytic activity of the phycosomes was 2% with a lipid

concentration of 0.025 mg/ml, this is within the measurement error range and hence the particles are safe for use. The curcumin loaded phycosomes showed around forty percent higher anticancer activity as compared to unloaded phycosomes. These results indicate that phycosomes may be used as a potential drug carrier in the field of nanotechnology.