Self-Assembled Hyaluronate/Protamine Polyelectrolyte Nanoplexes: Synthesis, Stability, Biocompatibility and Potential Use as Peptide Carriers

Abstract

This work investigates a new type of polyelectrolyte complex nanocarrier composed of hyaluronic acid (HA) and protamine (PROT). Small (approximately 60 nm) and negatively charged nanoparticles (NPs) with a polydispersity index of less than 0.2 were obtained with properties that were dependent on the mixing ratio, concentration of polyelectrolytes and molecular weight of HA. Salmon calcitonin (sCT) was efficiently (up to 100%) associated with the NPs, and the drug loading (9.6-39% w/w) was notably high, possibly due to an interaction between HA and sCT. The NPs released ∼ 70-80% of the sCT after 24 hours, with the estimated total amount of released sCT depending on the amount of HA and PROT present in the NPs. The isoelectric point of the NPs was close to pH 2, and the negative surface charge was maintained above this pH. The HA/PROT nanoplexes protected the sCT from enzymatic degradation and showed low toxicity to intestinal epithelial cells, and thus may be a promising oral delivery system for peptides.

Intermolecular interactions between salmon calcitonin, hyaluronate, and chitosan and their impact on the process of formation and properties of peptide-loaded nanoparticles

“…9 and Table 3 show 562 that less than 100% sCT was released from NPs in 24 h and it can be assumed that this 563 amount of sCT remained complexed to HA. Differences is the amount of sCT released are 564 seen for the various HA257/CS systems as described above in contrast to HA/protamine/sCT 565 NPs (Umerska et al, 2014), where all systems studied had similar properties and released 566 approximately 50% of the peptide in PBS after 1 hour of the studies. Therefore, when a 567 slower peptide release is required, HA257/CS NPs might be a better formulation choice.…”

“…Non-associated sCT was separated from NPs by a combined ultrafiltration-167 centrifugation technique (Centriplus YM-50, MWCO of 50 kDa, Millipore, USA) as 168 described earlier (Umerska et al, 2014). A total of 5 ml of sample were placed in the sample 169 reservoir (donor phase) of the centrifugal filter device and centrifuged for 1 hour at 3000 rpm.…”

“…Analysis of sCT content was performed using the HPLC system as described earlier 205 (Umerska et al, 2014). Briefly, standard solutions of sCT (1.5-50 µg/ml) were prepared in 206 pH 7.4 the peptide is expected to carry an overall charge of approximately 3+ (Epand et al, 236 1983).…”

“…As the measurements of transmittance and viscosity confirmed the formation of a 354 binary HA257/sCT complex, these parameters were also measured for ternary 355 HA257/CS/sCT systems. Transmittance values, which give information on the turbidity of 356 samples, depend on the concentration and the particle size of NPs (Umerska et al, 2014). 357…”

Chondroitin-based nanoplexes as peptide delivery systems – Investigations into the self-assembly process, solid-state and extended release characteristics

“…PROT offers a long history of use and established biological 105 effects and safety in humans (Reynolds et al, 2005). It has been demonstrated to form 106 polyelectrolyte complexes with oligonucleotides (Junghans et al, 2000; González Ferreiro et al, 107 2001) and glycosaminoglycans: hyaluronic acid (HA) (Umerska et al, 2014a) and heparin (Mori 108 et al, 2010). 109…”