查看文章

Glycol chitosan, a derivative of chitosan, can be hydrophobically modified by 5β-cholanic acid to impart amphiphilic properties that enable the self-assembly into nanoparticles in aqueous media at neutral pH. This nanoparticle system has shown initial success as a therapeutic agent in several model cell culture systems, but little is known about its stability against enzymatic degradation. The goal of this research was therefore to investigate the physicochemical properties of hydrophobically modified glycol chitosan nanoparticles (CNP) under exposure to lysozyme, a ubiquitous mammalian enzyme. Dynamic light scattering (DLS) revealed that the CNP vehicles had an average hydrodynamic diameter of 288.6 nm. These nanoparticles were able to encapsulate bovine serum albumin (BSA) at 87-90% efficiency. Varying the initial CNP: BSA mass ratio affected both particle size and total protein release, indicating a difference in complexation between the negatively charged protein and the positively charged chitosan polymer when more cargo is loaded. After 3 hours of exposure to lysozyme, CNP vehicles degraded to 10-150 nm particles, whereas BSA-loaded CNP degraded more extensively to predominantly 10-20 nm particles. Interesting, however, the encapsulated BSA was not fragmented as shown by SDS-PAGE. Minimal cytotoxicity of the CNP vehicles was observed in both rat osteosarcoma (ROS 17/2.8) and murine osteoblast-like (MC3T3-E1) cells, which internalized the nanoparticles within 2 hours. Taken together, these data suggest that hydrophobically modified glycol chitosan nanoparticles are a promising smart material for use in …