Physico-Chemical and Financial Comparisons of One-Step Iron Oxide Nanocrystal Syntheses for Nanoparticle Fabrication

摘要

Magnetic nanoparticles containing iron oxide are key technologies for molecular and cellular MRI, magnetic drug delivery, magnetic cell sorting and targeted thermal therapy. Size, coating, cost of production, and many other attributes of encased magnetite crystals dictate the quality of the particles. In this paper we compare two, one-step procedures for producing magnetite nanocrystals. Nanocrystals were synthesized and then encapsulated in poly(lactic-co-glycolic acid) (PLGA) to form magnetic nanoparticles. Multiple analytical methodologies were used to determine nanocrystal size, encapsulation efficiency by PLGA, total particle size and production cost. In the first method, iron oxide nanocrystals were synthesized using thermal decomposition of iron salts in the presence of 1,2-hexadecanediol, oleic acid and oleylamine. Nanocrystals were 6 nm in diameter and were encapsulated into PLGA with high efficiency without further modification, but were costly due to the procedure's starting material. The second method, involving thermal decomposition of salts solely in the presence of decanoic acid, produced 6, 10, and 20 nm diameter crystals, depending on the ratio of the decanoic acid to iron salt. Further, this method is similar to 23 times less expensive. Following an incubation step in oleic acid, encapsulation of iron oxide nanocrystals produced using the decanoic acid method was equal to that of the first method with equal overall nanoparticle size. Despite the popularity of the first method, these analyses suggest that the second method is better suited to large scale production of iron oxide nanocrystals for embedding in hydrophobic polymers.