Nanogels for delivery, imaging and therapy

Abstract

Nanogels are hydrogels having size in nanoregime, which is composed of cross-linked polymer networks. The advantages of nanogels include stimuli-responsive nature, easy drug loading, and higher drug-loading capacity, physical stability, versatility in design, stability of entrapped drug, and controlled release of the anti-inflammatory, antimicrobial, protein, peptide and anticancer drugs. Stimuli-responsive nature of nanogel is of particular importance in anticancer and anti-inflammatory drug delivery, as cancer and inflammation are associated with acidic pH, heat generation, and change in ionic content. Nanogels composed of muco-adhesive polymers provide prolonged residence time and increase the ocular availability of loaded drugs. By forming suitably sized complex with proteins or by acting as artificial chaperones, they thus help to keep the proteins and enzymes in proper confirmation necessary for exerting biological activity; nanogels can increase the stability and activity of protein/peptide drugs. Better drug penetrations achieved by prolonged contact with skin contribute much in transdermal drug delivery. When it comes to cancer drug delivery, the presence of multiple interactive functional groups in nanogels different targeting agents can be conjugated for delivery of the selective drugs. This review focuses on applications of nanogels in cancer drug delivery and imaging, anti-inflammatory, anti-psoriatic, transdermal, ocular and protein/peptide drug delivery and therapy.

Beyond chemotherapeutics: cisplatin as a temporary buckle to fabricate drug-loaded nanogels

“…Nanogel (NG), nanoparticles composed of crosslinked hydrophilic polymer networks, have demonstrated great potentials in loading drugs or dyes with different solubilities for therapeutic and imaging applications 16, 17 . Current strategies to encapsulate payloads into polymers are mainly self-assembly, crosslinking, emulsion and nanoprecipitation 18 , which may require complex preparations, tedious chemical purifications, and/or harsh conditions, that result in compromised drug efficiency or an increase in cost.…”

Advances in drug delivery systems based on synthetic poly(hydroxybutyrate) (co)polymers

“…This response of the hydrogels is mainly governed and tuned by the hydrogel composition, the cross-linking type (chemical or physical) and the degree of cross-linking. There are numerous applications of hydrogels including in particular vehicles for drug delivery, scaffolds for tissue engineering, actuators for optics and fluidics, and model extracellular matrices for biological studies [184][185][186][187][188][189][190]. However, PHB-based hydrogels used as DDS remain quite rare in comparison to the PHB-based nanoparticles, micelles or microparticles.…”

Peptide‐based supramolecular hydrogels for delivery of biologics

“…For this purpose, more effort should be devoted to investigating the peptide‐based nanogel system for systemic delivery, as inspired by the recently developed polymeric nanogels. The nanogels are nanosized crosslinked networks mostly composed of synthetic polymers and are very promising as biologics carriers because of their high loading capacity, high stability, and responsiveness to environmental factors . They are mostly produced by polymerization of monomers in nanoscale heterogeneous environments stabilized by surfactants or cross‐linking of preformed polymers.…”