A Review of Design and Fabrication Methods for Nanoparticle Network Hydrogels for Biomedical, Environmental, and Industrial Applications

Abstract

Nanoparticle network hydrogels (NNHs) in which nanoparticles are used as a key building block to build the gel network have attracted significant interest given their potential to leverage the favorable properties of both hydrogels (e.g., hydrophilicity, tunable pore sizes, mechanics, etc.) and a variety of different nanoparticles (e.g., high surface area, chemical activity, independently tunable porosity, mechanics) to create new functional materials. Herein, recent progress in the design and use of NNHs is comprehensively reviewed, with an emphasis on defining the typical gel morphologies/architectures that can be achieved with NNHs, the typical crosslinking approaches used to fabricate NNHs, the fundamental properties and functional benefits of NNHs, and the reported applications of NNHs in electronics (flexible electronics, sensors), environmental (sorbents, separations), agriculture, self‐cleaning‐materials, and biomedical (drug delivery, tissue engineering) applications. In particular, the way in which the NNH structure is applied to improve the performance of the hydrogel in each application is emphasized, with the aim to develop a set of principles that can be used to rationally design NNHs for future uses.

Novel Trends in Hydrogel Development for Biomedical Applications: A Review

“…It is also necessary to use enzymes as catalysts to favor the reaction [ 219 ] or, most commonly, free radical initiators, which are compounds that can generate free radicals by different stimuli. Temperature, UV irradiation, oxidation, microwave irradiation and gamma radiation have been used to induce radical generation [ 220 ].…”

Microgels and Nanogels for the Delivery of Poorly Water-Soluble Drugs

“…Compartmentalized microgels may contain a single hydrophobic nanoparticle (in which case they are typically referred to as core−shell microgels) or multiple nanoparticles (in which case they are typically referred to as nanocomposite or nanoparticle network microgels). 43 The hydrophobic nanoparticle domain promotes the encapsulation of poorly watersoluble therapeutics, while the hydrophilic outer microgel "shell" primarily (although not exclusively) regulates other microgel properties such as thermoresponsiveness, compressibility, and swelling. Compartmentalized microgels can be fabricated using two potential strategies, summarized below with examples.…”

Using the Intranasal Route to Administer Drugs to Treat Neurological and Psychiatric Illnesses: Rationale, Successes, and Future Needs

“…proteins, peptides, polynucleotides) [ 128 ]. The polymer matrix can also be designed to be responsive to physiological stimuli either in terms of forming the crosslinks (in situ gelling) or triggering the release of drugs (responsive); in particular, rapidly in situ forming hydrogels can be advantageous to deliver minimally viscous precursor solutions under the shear stress of nebulization (facilitating well-distributed spray uniformity and droplet size for optimal deposition) while ensuring high retention in the nasal cavity [ 114 , 136 , 137 ]. Creating nanoparticles of hydrogels, or incorporating other types of nanoparticles inside a hydrogel, can combine the useful benefits of a hydrogel with the penetration benefits of nanoparticles to create effective IN delivery vehicles [ 127 , 137 , 138 ].…”