Formation of Multidomain Hydrogels via Thermally Induced Assembly of PISA-Generated Triblock Terpolymer Nanogels

Abstract

Polymerization-induced self-assembly (PISA) is a rapidly evolving method for the efficient preparation of well-defined nano-objects. PISA-generated nano-objects have been explored in this work for the responsive formation of multidomain hydrogels by thermally induced assembly of doubly thermoresponsive triblock terpolymer nanogels. The nanogels consist of a thermoresponsive poly­(diethylene glycol ethyl acrylate) (PDEGA) outer block with a lower thermal transition temperature, a hydrophilic poly­(N,N-dimethyl­acrylamide) (PDMA) midblock, and a N,N′-methylene­bis­(acrylamide) (BIS) cross-linked, thermoresponsive poly­(N-isopropyl­acrylamide) (PNIPAM) core block with a higher thermal transition temperature. The unique location of these two thermoresponsive blocks of differing transition temperatures in the PDEGA–PDMA–P­(NIPAM-co-BIS) nanogels is rationally designed to facilitate room-temperature gelation and is synthetically realized via judicious selection of water–ethanol mixtures under dispersion polymerization conditions. The nanogels were characterized by turbidimetry, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Gelation behavior of the nanogels was investigated by the inverted vial method as well as dynamic rheology sweeps. In comparison with PNIPAM–PDMA–P­(DEGA-co-BIS) nanogel and a triblock terpolymer of similar composition, the PDEGA–PDMA–P­(NIPAM-co-BIS) nanogels exhibit a good combination of gelation sensitivity and gel strength. The gelation ability, sensitivity, and mechanical properties are affected by the block ratios as well as the cross-linking density in the core of the nanogels.

Preparation of a novel injectable in situ-gelling nanoparticle with applications in controlled protein release and cancer cell entrapment

“…13,17,18 Among these particle-based thermogelling systems, poly(N-isopropylacrylamide) (PNIPAM)-based microgels are the most studied and have been widely explored as in situ forming scaffolds for use in tissue engineering. 13,17,[19][20][21][22][23][24][25][26] PNIPAM polymer has a lower critical solution temperature (LCST) at near to physiological temperature therefore, PNIPAM-based microgels can be used for reversible cell adhesion or detachment and for triggered release of therapeutics. 24,25 However, there are limitations for long-term application in biotechnology.…”

Template‐Directed Fabrication of Anatase TiO2 Hollow Nanoparticles and Their Application in Photocatalytic Degradation of Methyl Orange

“…PISA strategy allows fabricating of polymeric nanoparticles at much high concentrations, and has become a powerful strategy for fabrication of polymeric nanoparticles. [27][28][29][30][31][32] In this paper, diblock copolymer poly(glycerol monomethacrylate)-block-poly(2-dimethylaminoethyl methacrylate) (PGMMA-PDMAEMA-CTA) was synthesized at first, and then used as the macro RAFT agent in the following RAFT dispersion polymerization of benzyl methacrylate (BzMA) to fabricate polymeric nanoparticles (Scheme 1A). The polymeric nanoparticles consisting of corona-shell-core three layers with PGMMA as the corona, PDMAEMA as the shell, and PBzMA as the core were fabricated at a final concentration of about 210 mg/g via the PISA strategy.…”

A Stimuli-Responsive Hydrogel with Reversible Three-State Transition Controlled by Redox Stimulation

“…For stimuli‐responsive hydrogels, some crucial drug release applications or tissue engineering applications have been developed extensively. The principal manifestations of stimuli‐response hydrogels are sol‐gel transition, swelling–shrinking process, and mechanical change . However, two‐state sol‐gel transition is still one of the most common expressions for stimuli‐response.…”