Stimuli-responsive polypeptide nanogels for trypsin inhibition.

A new type of hydrophilic, biocompatible, and biodegradable polypeptide nanogel depots loaded with the natural serine protease inhibitor α1-antitrypsin (AAT) was applied for the inhibition of the inflammatory mediator trypsin. Two types of nanogels were prepared from linear synthetic polypeptides based on biocompatible and biodegradable poly[ -(2-hydroxyethyl)-ʟ-glutamine-- -propargyl-ʟ-glutamine-- -(6-aminohexyl)-ʟ-glutamine]-- -[2-(4-hydroxyphenyl)ethyl)-ʟ-glutamine] (PHEG-Tyr) or biocompatible -ʟ-lysine-grafted α,β-poly[(2-propyne)-ᴅ,ʟ-aspartamide--(2-hydroxyethyl)-ᴅʟ-aspartamide--(2-(4-hydroxyphenyl)ethyl)-ᴅʟ-aspartamide] ( -Lys-NG). Both nanogels were prepared by HRP/HO-mediated crosslinking in inverse miniemulsions with pH and temperature-stimuli responsive behavior confirmed by dynamic light scattering and zeta potential measurements.

Biocompatible polypeptide nanogel: Effect of surfactants on nanogelation in inverse miniemulsion, in vivo biodistribution and blood clearance evaluation.

Horseradish peroxidase (HRP)/HO-mediated crosslinking of polypeptides in inverse miniemulsion is a promising approach for the development of next-generation biocompatible and biodegradable nanogels. Herein, we present a fundamental investigation of the effects of three surfactants and their different concentrations on the (HRP)/HO-mediated nanogelation of poly[N-(2-hydroxyethyl)-l-glutamine-ran-N-propargyl-l-glutamine-ran-N-(6-aminohexyl)-l-glutamine]-ran-N-[2-(4-hydroxyphenyl)ethyl)-l-glutamine] (PHEG-Tyr) in inverse miniemulsion. The surfactants sorbitan monooleate (SPAN 80), polyoxyethylenesorbitan trioleate (TWEEN 85), and dioctyl sulfosuccinate sodium salt (AOT) were selected and their influence on the nanogel size, size distribution, and morphology was evaluated.