Soft nanoparticles are interesting materials due to their size, deformability, and ability to host guest molecules. Surface properties play an essential role in determining the fate of the particles in biological medium, and coating of the nanoparticles (and polymers) with carbohydrates has been found to be an efficient strategy for increasing their biocompatibility and fine-tuning other important properties such as aqueous solubility. In this work, soft nanogels of poly( N -vinylcaprolactam), PNVCL, were surface-functionalized with different glucose and maltose ligands, and the colloidal properties of the gels were analyzed. The PNVCL nanogels were first prepared via semibatch precipitation polymerization, where a comonomer, propargyl acrylate (PA), was added after preparticle formation. The aim was to synthesize “clickable” nanogels with alkyne groups on their surfaces. The nanogels were then functionalized with two separate azido-glucosides and azido-maltosides (containing different linkers) through a copper-catalyzed azide–alkyne cycloaddition (CuAAc) click reaction. The glucose and maltose bearing nanogels were thermoresponsive and shrank upon heating. Compared to the PNVCL–PA nanogel, the carbohydrate bearing ones were larger, more hydrophilic, had volume phase transitions at higher temperatures, and were more stable against salt-induced precipitation. In addition to investigating the colloidal properties of the nanogels, the carbohydrate recognition was addressed by studying the interactions with a model lectin, concanavalin A (Con A). The binding efficiency was not affected by the temperature, which indicates that the carbohydrate moieties are located on the gel surfaces, and are capable of interacting with other biomolecules independent of temperature. Thus, the synthesis produces nanogels, which have surface functions capable of biorelevant interactions and a thermoresponsive structure. These types of particles can be used for drug delivery.

Soft poly(N-vinylcaprolactam) (PNVCL) based nanogels were prepared and surface-decorated with gold nanoparticles (AuNPs). The applicability of the hybrid nanogels (PNVCL-AuNPs) as carriers for low molar mass substances was of special interest. AuNPs protected with a mixture of 11azidoundecanothiol and 11-mercaptoundecanoic acid were bound to propargyl functionalized PNVCL based nanogels. Acidic groups on the surfaces of AuNPs and PNVCL based nanogels stabilize the particle dispersions against precipitation above the phase transition temperature of PNVCL. Both the neat PNVCL nanogels and the PVCL-AuNPs shrink upon heating the dispersions. Even though the AuNPs are mainly located in the soft surface layer of the nanogels, the PNVCL-AuNPs respond to visible light as well as to radio-frequency (RF) irradiation by shrinking due to the AuNPs acting as nanoheaters. Interactions of linear PNVCL, PNVCL nanogels and PNVCL-AuNPs with two fluorescent probes were studied as function of increasing temperature. Once bound to the polymer the fluorescent probe may or may not be released from it, depending on its polarity and water solubility. Presence of AuNPs changed the release behavior of the water soluble charged fluorescent probe from the nanogels.

A thermoresponsive polymer, poly(N-vinylcaprolactam) (PNVCL), was synthesized in an emulsion above its thermal transition temperature to produce particles via polymerization induced self-assembly (PISA).

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Various copper‐based catalyst systems and reaction conditions were studied in the graft copolymerization of N,N‐dimethylacrylamide (DMAam) with a cellulose‐based macroinitiator by controlled radical polymerization. The cellulose macroinitiator with degree of substitution DS = 0.44 was synthesized from dissolving softwood pulp in a LiCl/DMAc solution. The graft copolymerizations of DMAam, using the cellulose macroinitiator and various copper‐based catalyst systems, were then carried out in DMSO solutions. The copolymerization kinetics was followed by 1H NMR. Water‐soluble cellulose‐g‐PDMAam copolymers were comprehensively characterized by ATR‐FTIR and 1H NMR spectroscopies and SEC analyses. DLS and steady‐shear viscosity measurements revealed that when the DPgraft of the cellulose‐g‐PDMAam copolymer is high enough, the copolymer forms a more compact structure in water. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012