Effects of the Molecular Weight of Hyaluronan on the Conformation and Release Kinetics of Self-Assembled 5-Fluorouracil-loaded Lysozyme-Hyaluronan Colloidal Nanoparticles.

Lysozyme (LYS) and hyaluronan with low (HA1: 3 kDa), medium (HA2: 120 kDa), and high (HA3: 1200 kDa) molecular weights were used to fabricate lysozyme-hyaluronan colloidal nanoparticles using a green self -assembly method. Fourier transform infrared spectroscopy indicated that hydrogen bonding, hydrophobic and electrostatic interactions promoted the formation of the colloidal nanoparticles. The hydrophobic area of pre-pared colloidal nanoparticles was quantified using a pyrene fluorescent probe, and the results showed that the LYS-HA3 nanoparticles had the strongest hydrophobic capacity. Furthermore, 5-fluorouracil (5-Fu) was used to evaluate encapsulation performance, demonstrating that the LYS-HA3 nanoparticles had the highest encapsu-lation ability (>90 %). All prepared 5-Fu-loaded lysozyme-hyaluronan (5-Fu@LYS-HA) colloidal nanoparticles exhibited excellent long-term storage stability at 4 degrees C for 60 days. Cellular uptake and in vitro release results indicated that the LYS-HA2 nanoparticles exhibited the highest cellular uptake efficiency, and the LYS-HA3 nanoparticles had the best slow-release effect, while the release process was mainly controlled by the combi-nation of Fickian diffusion and structural relaxation, respectively. This study demonstrates the influence of molecular weight on the conformational and structural properties of colloidal nanoparticles, which has impli-cations for the design of insoluble drug self-assembly systems.