Presentation Authors: Nikhil Pandey*, Andres Urias, Valinda Jones, Serkan Yaman, Amirhossein Hakamivala, Boris Rodionov, Jun Liao, Arlington, TX, Philippe Zimmern, Dallas, TX, Kytai Nguyen, Yi Hong, Arlington, TX
Introduction: Mussel inspired approaches to create improved bioadhesives involve synthetic hydrogel systems with catechol moieties grafted onto polymer chains , albeit these have lower adhesiveness compared to mussel&[prime]s strong underwater adhesion. We have demonstrated that the combination of nanoparticles (NPs) and mussel-inspired hydrogel systems can create enhanced tissue adhering nanocomposites (NCs) . Herein we further optimize the tissue adhesion of a nanocomposite of hyaluronate based biomimetic, mussel-inspired hydrogel and PLGA or polydopamine NPs, within a tissue interface, by varying the nanoparticles types, sizes and concentrations.
Methods: Dopamine was grafted onto sodium hyaluronate (HA) (MW:151-300KDa) using EDC/NHS aqueous chemistry, creating a mussel-inspired polymer (HA-Dopa) . NCs were formulated combining HA-Dopa with, poly (D, L-lactic-co-glycolic acid) (PLGA) NPs, or N-hydroxysuccinimide (NHS) modified PLGA NPs (PLGA-NHS) or polydopamine (polydopa) NPs using sodium metaperiodate (PI) as a cross-linker. NCs tissue adhesiveness (Uniaxial lap shear testing, cross head speed:10mm min-1) on a porcine skin-muscle interface (Figure 1A), along with effect of nanoparticle concentration (0-20%w/v), type, and size on the adhesion was investigated. Finally, in vitro cytocompatibility of the optimized NCs was evaluated using human dermal fibroblasts (HDFs).
Results: NP mediated enhancement in tissue adhesion resulted in maximal lap shear strength values of 47.1 Â± 3.2 kPa in the HA-Dopa-Polydopa group versus HA-Dopa alone (20.1 Â± 2.8 kPa) (Figure 1B). The 100-200 nm sized polydopamine NPs were optimal for maximal increase in tissue adhesiveness of HA-Dopa hydrogels, while variation of nanoparticle concentrations in all NC groups revealed the adhesive strength increase to be concentration-dependent.
Conclusions: We report that these nanocomposites may serve as adhesives for applications in tissue interfacing, such as temporary bio-glues for tissue adhesion.