Lipid Constituents of Diatoms (Halamphora) as Components for Production of Lipid Nanoparticles

Abstract

Lipid nanocarriers smaller than 200 nm may be used as pharmaceutical/cosmetic raw materials as they are able to penetrate the skin. The nanostructured lipid carriers (NLCs) based on microalgae oil (Schizochytrium) and lipids extracted from diatoms (Halamphora cf. salinicola (strain SZCZM1454A)) were produced by the HSH (high shear homogenization) method. Fatty acid profile of crude oil from diatoms indicated the presence of palmitoleic, palmitic, stearic acid, oleic and myristic acids as the most common fatty acids in the strain investigated. The quantitative composition and the synthesis condition of NLC dispersions were optimized by using the full factorial designs. The physicochemical parameters of the obtained lipid nanocarriers were characterized by SEM, DSC and XRD measurements and the fraction with the optimum parameters (size below 200 nm, polydispersity index not exceeding 0.2 and zeta potential higher than +45 mV) was selected for further study. The positive charge of the obtained lipid nanoparticles is beneficial as permits electrostatic bonding with the negatively charged skin surface. As follows from stability tests, the NLCs obtained could be stored at room temperature.

Removal of the Basic and Diazo Dyes from Aqueous Solution by the Frustules of Halamphora cf. salinicola (Bacillariophyta)

“…The SZCZM1454 H. cf. salinicola originates from Köyceğiz Lake in Turkey [ 10 ], which contains subaqueous hot springs [ 76 ]. Therefore, the strain could be considered thermophilic, hence the higher temperature requirements for cultivation.…”

“…The SZCZM1454 Halamphora cf. salinicola strain [ 10 ] was acquired from the Szczecin Diatoms Culture Collection (SZCZ), University of Szczecin, Institute of Marine and Environmental Sciences, Poland. For growth rate determination, the monoclonal culture was maintained in a 100 mL Erlenmeyer flask containing 35 ppt Guillard’s artificial seawater f/2 medium [ 131 ] (1 L of medium contained 880 µM NaNO 3 , 36 µM NaH 2 PO 4 H 2 O, 106 µM Na 2 SiO 3 9H 2 O, trace metal: 0.08 µM ZnSO 4 7H 2 O, 0.9 µM MnSO 4 H 2 O, 0.03 µM Na 2 MoO 4 2H 2 O, 0.05 µM CoCl 2 6H 2 O, 0.04 µM CuCl 2 2H 2 O, 11.7 µM FeCl 3 6H 2 O, 11.7 µM Na 2 EDTA 2H 2 O, vitamin B12, biotin and thiamine) under the following conditions: 20 °C constant temperature and 100 µmol s −1 m −2 white light under a under a 12:12 day/night light cycle in a plant growth chamber (FITO1400i, Biogenet, Poland) for 24 days.…”

“…The SZCZM1454 Halamphora cf. salinicola strain [10] was acquired from the Szczecin Diatoms Culture Collection (SZCZ), University of Szczecin, Institute of Marine and Environmental Sciences, Poland. For growth rate determination, the monoclonal culture was maintained in a 100 mL Erlenmeyer flask containing 35 ppt Guillard's artificial seawater f/2 medium [131] C constant temperature and 100 µmol s −1 m −2 white light under a under a 12:12 day/night light cycle in a plant growth chamber (FITO1400i, Biogenet, Poland) for 24 days.…”

“…The dried frustules (20 ± 0.5 mg) were exposed to 15 mL of 20.0 mg L −1 CR, CV, and MG solutions (pH-7) in a Falcon tube and stirred at 3000 rpm at 20 • C for 4 h. The kinetics of adsorption were recorded spectrophotometrically (UV-Vis DR 6000, HACH-Lange) at 499 nm (CR), 586 nm (CV), and 616 nm (MG) at different time points: 5, 10, 15, 30, 45, 60, 90, 120, 180, and 240 min. The influence of different initial concentrations of dye was investigated by measuring 10 mg of the cleaned frustules in Falcon tubes containing various concentrations (5,10,15,20,50, and 100 mg L −1 ) of CR, CV, and MG. After the mixture reached equilibrium (120 min for CR and MG and 60 min for CV), the removal was recorded spectrophotometrically, as mentioned above. The quantity of adsorbed MB by the frustules was calculated as follows (Equation ( 2)):…”

“…Halamphora spp. has gained attention due to its ability to accumulate a high amount of triglycerides (TAG) for biodiesel production [ 4 , 5 , 6 , 7 ], fatty acids for the aquaculture [ 8 , 9 ] and cosmetics industries [ 10 ], as well as fucoxanthin and chrysolaminarin with antioxidant, anticancer, and immunomodulatory capacities for pharmaceutical purposes [ 11 , 12 ]. Thus, Halamphora strains can be cultivated on an industrial scale for biodiesel, while wastes from lipid extraction may be purified and clean biosilica can be used in different applications.…”