Amphiphilic micro‐ and nanogels: Combining properties from internal hydrogel networks, solid particles, and micellar aggregates

Abstract

Polymeric micro-and nanogels are defined by their water-swollen hydrophilic networks that can often impart outstanding biocompatibility and highcolloidal stability. Unfortunately, this highly hydrophilic nature limits their potential in areas where hydrophobic or amphiphilic interactions are required, for example, the delivery of hydrophobic cargoes or tailored interactions with amphipathic (bio-)surfaces. To overcome this limitation, amphiphilic microÀ/nanogels are emerging as new colloidal materials that combine properties from hydrogel networks with hydrophobic segments, known from solid hydrophobic polymer particles or micellar cores. The ability to accurately adjust the balance of hydrophobic and hydrophilic components in such amphiphilic colloidal systems enables new tailored properties. This opens up new applications ranging from the

Synthesis and characterization of dual-responsive poly(N-vinylcaprolactam-co-N-methylolacrylamide) nanogels

“…T c of thermoresponsive polymers can be tuned by adding hydrophilic or hydrophobic co-monomers. Hydrophilic co-monomers shift the T c to higher temperatures because more energy is needed to destroy the hydrogen bonds, while hydrophobic co-monomers showed a contrary effect [ 22 ]. Figure 3 shows that all nanogels exhibit LCST-type phase transition behavior, and the T c of nanogels increased with the addition of NMA.…”

Aqueous microgels with engineered hydrophobic nano-domains

“…Typical polymerization techniques applied in the formation of microgels comprising an amphiphilic network can be divided in three general approaches: the incorporation of This journal is © The Royal Society of Chemistry and IChemE 2022 hydrophobic domains during microgel synthesis, the crosslinking of self-assembled amphiphilic copolymers, and the post-modification of precursor gel particles. A very well researched overview on synthesis methods for the preparation of microgels with amphiphilic polymer network structure, as well as their advantages and disadvantages, can be found in the recently published review by Biglione et al 42 In contrast, little attention has been paid so far to the classification of amphiphilic microgel systems with respect to the nature of the hydrophobic domains present. Thus, the following sections of this review are devoted to different types of hydrophobic nano-domains incorporated in microgels, and the different synthetic ways to generate them, on the basis of recently published examples.…”

Dual-reactive nanogels for orthogonal functionalization of hydrophilic shell and amphiphilic network

“…Thus, amphiphilic NGs with a hydrophilic polymer matrix and embedded hydrophobic groups are emerging to expand the therapeutic potential of conventional NGs. 5–7…”

“…Thus, amphiphilic NGs with a hydrophilic polymer matrix and embedded hydrophobic groups are emerging to expand the therapeutic potential of conventional NGs. [5][6][7] To address the challenging synthesis of such amphiphilic colloids (i.e., combine groups of opposing solubility in a single colloidal system) we have recently developed a versatile approach that uses reactive poly(pentafluorophenyl methacrylate) (PPFPMA) precursor nanogels. Transferring the concept of post-polymerization functionalization from linear polymers [8][9][10] to crosslinked NG networks, 6,[11][12][13] allows the preparation of NG libraries with varying hydrophobicity but similar colloidal features.…”