(164ae) Shear-Responsive Adhesion and Detachment of Dendrimer Coatings on Nano- and Micro-Particles

Recent years have witnessed an increased interest in synthesizing and studying internally functionalized dendrimers (IFDs) and their applications in drug and gene delivery, tissue engineering, and catalysis [1]. This work presents a shear-responsive coating comprised of DendriPeps, a novel dendrimer architecture featuring a poly(amidoamine) (PAMAM) backbone hybridized with di-peptide segments [2,3]. The DendriPep investigated, G.3-Lys₈-OH, displays 8 internal primary amine groups and 16 terminal hydroxyl groups. Fluorescent confocal microscopy and transmission electron microscopy demonstrate the encapsulation of polystyrene-based nanoparticles and poly(N-isopropyl acrylamide)-co-(acrylic acid) microgels with a dynamic DendriPep shell. The individual G.3-Lys₈-OH dendrimer units constitute a functional coating that disassembles when exposed to shear and reconstitutes at rest. The shear-responsive nature of this encapsulation system was further investigated by developing shear-responsive hybrid micro-particle/DendriPep delivery systems. Most notably, the equilibrium release and the rate of release of peptides from DendriPep coated microgels are quantitatively modulated by applying shear stress. When introduced to nano- and micro-substrates, the DendriPep shell confers (i) inherent functionality attributed to their architecture and (ii) shear-responsiveness, motivating further assessments of their biomedical potential.

References:

[1] Smith, R. J.; Gorman, C.; Menegatti, S. Synthesis, Structure, and Function of Internally Functionalized Dendrimers. Journal of Polymer Science. 2021.

[2] Smith, R. J.; Gorman, C. B.; Menegatti, S. DendriPeps: Expanding Dendrimer Functionality by Hybridizing Poly(Amidoamine) (PAMAM) Scaffolds with Peptide Segments. Macromol. Rapid Commun. 2019.

[3] Smith, R. J.; Fabiani, T.; Wang, S.; Ramesh, S.; Khan, S.; Santiso, E.; Silva, F. L. B.; Gorman, C.; Menegatti, S. Exploring the Physicochemical and Morphological Properties of Peptide‐hybridized Dendrimers (DendriPeps) and Their Aggregates. J. Polym. Sci. 2020, pol. 20200277.