Nanoparticle-Hydrogel Composites: From Molecular Interactions to Macroscopic Behavior

Abstract

Hydrogels are materials used in a variety of applications, ranging from tissue engineering to drug delivery. The incorporation of nanoparticles to yield composite hydrogels has gained substantial momentum over the years since these afford tailor-making and extend material mechanical properties far beyond those achievable through molecular design of the network component. Here, we review different procedures that have been used to integrate nanoparticles into hydrogels; the types of interactions acting between polymers and nanoparticles; and how these underpin the improved mechanical and optical properties of the gels, including the self-healing ability of these composite gels, as well as serving as the basis for future development. In a less explored approach, hydrogels have been used as dispersants of nanomaterials, allowing a larger exposure of the surface of the nanomaterial and thus a better performance in catalytic and sensor applications. Furthermore, the reporting capacity of integrated nanoparticles in hydrogels to assess hydrogel properties, such as equilibrium swelling and elasticity, is highlighted.

Role of Nanoparticle–Polymer Interactions on the Development of Double-Network Hydrogel Nanocomposites with High Mechanical Strength

“…One approach that has gained significant interest over the past couple of decades is the incorporation of nanoparticles, which can enable the formation of additional crosslinks within the polymer network and contribute to enhancements in the mechanical strength of hydrogels. It has been shown that nanoparticle-mediated physical crosslinking can complement chemical crosslinking and that the combination of chemical and physical crosslinking can lead to enhancements in an elastic modulus that is greater than with either alone [14][15][16]. However, previous work suggests that there might be an upper limit to enhancements in mechanical strength achievable through the addition of nanoparticles, possibly due to the existence of a saturation point in the gains achievable through a combination of chemical and physical crosslinking [15,17,18].…”

Influence of incorporation of SiO2 and ZrO2 nanoparticles on some physical and mechanical properties of thermoplastic resin material

“…Furthermore, they can increase their porosity which leads to an increase in water sorption of thermoplastic resin. Additionally, the increased porosities in this resin may be due to the inclusion of air during the injection procedure of the modified resins (37) . However, the significant increases in water solubility of thermoplastic resin may be due to their lower cross-linkage as its chemical structure which mainly linear polymer structure with intermolecular bonding mechanism which adversely affected by the incorporation of these nanoparticles (1,15,24,37) .…”

Nanoparticles to Improve the Efficacy of Peptide-Based Cancer Vaccines

“…Alum has been used as adjuvant in combination with CpG oligodeoxynucleotide (CpG) and innate defense regulator peptide HH2 for improving anti-tumor immune responses. The CpG-HH2 complex significantly enhanced the production of IFN-γ, TNF-α and IL-1β, promoted the uptake of antigen and strengthened the activation of p38, Erk1/2 and NF-κB in vitro, compared to CpG or HH2 alone [34]. Aluminum hydroxide nanoparticles (~100 nm) containing OVA was shown to have a strong in vitro immune activity and to delay tumor progression in vivo after immunization with a dose lower than traditional aluminum hydroxide (~9 µm) [35].…”