2021 Annual Meeting

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

Authors

Srivatsan Ramesh - Presenter, North Carolina State University
Ryan Smith, North Carolina State University
Christopher Gorman, North Carolina State University
Stefano Menegatti, North Carolina State University
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.