Colloidally stable polypeptide‐based nanogel: Study of enzyme‐mediated nanogelation in inverse miniemulsion

Abstract

The current work presents a pivotal study of the nanogelation of the linear poly(N5‐2‐hydroxypropyl‐L‐glutamine) polymer precursor containing tyramine (TYR) units in an inverse miniemulsion by horseradish peroxidase/H2O2‐mediated crosslinking. The effects of various nH2O2/nTYR ratios on the kinetics of nanogelation in the inverse miniemulsion and on the reaction time are investigated by linear sweep voltammetry, while the formation of dityramine crosslinking is explored by fluorescence spectroscopy. The study is completed using dynamic light scattering measurements, nanoparticle tracking analysis, and cryogenic transmission electron microscopy to acquire comprehensive information about the formed nanoparticulate systems. With the optimal ratio nH2O2/nTYR = 2, the strategy yields in the high‐quality ~ 130 nm poly(amino acid)‐based nanogel, which is prepared in 2 h. The nanogel is colloidally stable under different temperature and pH conditions for over 168 h. Moreover, the demonstrated nanogel is noncytotoxic for HeLa cells and human primary fibroblasts and is quickly enzymatically hydrolyzed into small fragments during a biodegradation study in human blood plasma. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48725.

Stimuli-responsive polypeptide nanogels for trypsin inhibition

“…Figure 2b shows that the zeta potential of PHEG-Tyr nanogel was not significantly affected by pH change. It was slightly anionic due to excess of carboxyl end groups and hydroxy groups [23]. Negligible difference could be seen between the measurements at 25 °C with an average zeta potential of ca.…”

“…In contrast, in the presence of SPAN 80 surfactant, the final nanogel was more irregular in shape while the yield of nanogelation was increased. The in vitro and in vivo tests proved biocompatibility and biodegradability of PHEG-Tyr nanogel and biocompatibility of N α -Lys-NG nanogel [23][24][25]. In this study, we attempt to obtain improved shape and morphology of PHEG-Tyr nanogel by combining surfactant SPAN 80 with surfactant TWEEN 85 based on a previous study presenting the stabilization effect of TWEEN 85 on HRP/H 2 O 2 -mediated nanogelation in inverse miniemulsion [24].…”

“…The synthetic polypeptides polyglutamine PHEG-Tyr and zwitterionic polyaspartamide N α -Lys-NG, which were prepared and characterized according to earlier published procedures [23][24][25], were nanogelated in inverse miniemulsion via HRP/H 2 O 2 crosslinking to obtain chemically dityramine-crosslinked nanogels [23]. Our previous studies examined the effect of different surfactants on the final properties of PHEG-Tyr nanogel, showing that in the presence of TWEEN 85 surfactant a spherical nanogel with low yield was obtained.…”

“…(PHEG-Tyr) polypeptide precursors by HRP/H 2 O 2 -mediated crosslinking in inverse miniemulsion including the synthetics for these polymer precursors [23][24][25]. Our effort resulted in the development of new types of polypeptide nanogels with potential for biological applications [24,25].…”

Bio-Orthogonal Nanogels for Multiresponsive Release

“… 25 Additionally, the miniemulsion process is compatible with a wide variety of chemistries, allowing the use of a robust bio-orthogonal gelation process. 26 − 29 …”