Author
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Evans, Kervin |
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Skory, Christopher |
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Compton, David |
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Kim, Sanghoon |
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Appell, Michael |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 6/27/2020 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Introduction: In an effort to acquire delivery systems capable of controlled release of new bio-based material, we have developed a novel encapsulation method using bio-based polymeric materials derived from sucrose. Water-insoluble a-glucans produced from sucrose using recombinant Leuconostoc mesenteroides glucansucrase were converted into nanoparticles through high-pressure homogenization and shown to encapsulate hydrophobic compounds. The work presented here focuses on characterizing the physical stability of these nanoparticles. Methods: Dried a-glucans (~3 mg) were subjected to thermal property analysis from 4' to 120'. Nanoparticles were formed using high-pressure homogenization. Fluorescence analysis of the hydrophobic properties of the nanoparticles were conducted from 4' to 86' using DPH fluorescent probe. Stability analysis was conducted on nanoparticles by measuring size/zeta potential changes over 225 days, and at acidic (pH 5.5), neutral (pH 7.4) and basic (pH 10) conditions. Accelerated exposure analysis was conducted for 6-hr intervals at 25', 37' and 60', respectively. Stability and accelerated exposure analysis were conducted on nanoparticles free of DPH. Results: Thermal analysis revealed that the a-glucans exhibited a small, broad endothermic peak at ~ 70' which was quite different from a-glucans made from Lactobacillus reuteri (Ispirli, Sagdic et al. 2019). DPH fluorescence analysis demonstrated that a hydrophobic core has possible internal unfolding at 70'. DLS analysis of DPH-free nanoparticles indicate that size changed little over 225 days and the zeta potential remained low and constant (~ -5 mV). DLS analysis also revealed that nanoparticle diameters were between 115 and 122 nm, and zeta potentials were between -0.3 and -1.3 mV at pH 5.5, 7.4 and 10. Accelerated exposure analysis revealed that the DPH-free nanoparticles were ~ 108 nm for 6 hrs at 25' and for first 2 hrs at 37'; size increased and stabilized to ~ 121 nm over the next 2 hrs at 37'. Nanoparticle size was between 108 and 119 nm during 6 hrs at 60' and returned to 119 nm after a gradual cool-down back to 25'. The zeta potential of the nanoparticles became increasingly negative, peaking around -52 mV after 2 hrs at 37'. The zeta potential gradually decreased negatively over the next 8 hrs from 37-60', reaching approximately -39 mV. The gradual cool-down resulted in the zeta potential spiking to ~ -65 mV and returning to -39 mV. Conclusion: Water-insoluble a-glucans form highly robust nanoparticles formed through high-pressure homogenization that have the potential to be developed as a novel, biodegradable delivery system. |