Vaterite/Fucoidan Hybrid Microparticles: Fabrication, Loading of Lactoferrin, Structural Characteristics and Functional Properties

Fucoidan is of considerable interest for the development of drug carriers. The inclusion of fucoidan allows calcium carbonate microparticles in the form of vaterite to acquire new properties, enabling their use in the immobilization of protein preparations. In this work, we investigated the properties of hybrid vaterite microparticles with fucoidan from <i>Fucus vesiculosus</i> obtained by co-precipitation and loaded with recombinant human lactoferrin from goats. The hybrid microparticles had a smaller diameter (3-4 µm), larger surface area (35-36 m²g^-1), smaller pore size (5-10 nm average), and more negative ζ-potential (-(11-13) mV) than the control vaterite microparticles. The incorporation of lactoferrin into the microparticles by co-precipitation in complex with fucoidan was greater than when the protein was adsorbed onto the hybrid microparticles. Microparticles with fucoidan and lactoferrin were stable in acidic environments, released both components over a prolonged period at pH 7.4, and possessed mucoadhesive properties and anticoagulant activity. The antibacterial properties of hybrid microparticles with fucoidan and lactoferrin against <i>Bacillus subtilis</i> were characterized. Microparticles of vaterite with fucoidan can serve as a platform for the microfabrication of effective means of delivering therapeutic proteins.