Exploring the Effects of Nanoparticle Incorporation on the Mechanical Properties of Hydrogels

Abstract

Recent studies have expanded our understanding of the effects of nanoparticles on hydrogel mechanical properties. However, further studies are needed to validate the generality of these findings, as well as to determine the exact mechanisms behind the enhancements afforded by the incorporation of nanoparticles. In this study, we performed rotational rheological characterizations of chemically crosslinked poly(acrylamide) hydrogels incorporating silica nanoparticles to better understand the role of nanoparticles on the enhanced properties of hydrogel nanocomposites. Our results indicate that incorporating nanoparticles can lead to enhancements in hydrogel elastic moduli greater than the maxima obtainable through purely chemical crosslinking. Moreover, we find that the increases in elastic moduli due to the addition of nanoparticles not only depend on particle concentration, but also on the monomer and chemical crosslinker concentration. Finally, our data indicates a strong role for pseudo-crosslinking mediated by noncovalent interactions between the nanoparticles and hydrogel polymers on the observed reinforcements. Collectively, our results shed further insight into the role of nanoparticles on enhancements of mechanical properties of hydrogels and may thereby facilitate engineering specific mechanical properties in a wide range of hydrogel nanocomposite systems.

Nanocomposite hydrogel microneedles: a theranostic toolbox for personalized medicine

“…To achieve the desired performance, a better understanding of NP–matrix interactions and the mechanisms involved in the formation of these composite systems is needed. Special attention should be paid to the following: effective incorporation of the NP component to maximize therapeutic loading while maintaining the integrity of each component; tunable mechanical performance to match application-specific requirements; biocompatibility, which is essential in all biomedical applications but may be compromised during gelation or degradation; and long-term stability to minimize treatment frequency [ 81 ]. Achieving a uniform distribution of NPs in HFMs is thus a multidimensional challenge that requires careful consideration of hydrogel formulation, NP properties, and fabrication methods.…”

“…Achieving a uniform distribution of NPs in HFMs is thus a multidimensional challenge that requires careful consideration of hydrogel formulation, NP properties, and fabrication methods. Advanced imaging and spectroscopic techniques are valuable tools for characterizing and optimizing NP distribution within the hydrogel matrix, ultimately enhancing the performance of hydrogel microneedle drug delivery systems [ 81 ].…”

Roadmap on multifunctional materials for drug delivery

“…Also rheology may be used to determine the mechanisms behind the enhancements afforded by the incorporation of NPs. For example, Zaragoza and Asuri performed rotational rheological characterizations of chemically crosslinked poly(acrylamide) hydrogels with embedded silica NPs [ 84 ]. They found that pseudo-crosslinking, governed by noncovalent interactions between the NPs and the hydrogel polymers, plays an important role in the observed reinforcements.…”