Synthesis and volume phase transition of concanavalin A-based glucose-responsive nanogels

Abstract

A glucose-responsive nanogel that can undergo reversible and rapid volume phase transitions is made of ConA interpenetrated in a poly(NIPAM) network.

Switchable glucose-responsive volume phase transition behavior of poly(phenylboronic acid) microgels

“…The <D h > values as a function of the solution pH were then normalized by a minimum hydrodynamic radius (<D h > 0,pH ) within the experimental pH window, because there was a difference of the size between pPBA-1 and pPBA-2 microgels. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Those results indicated that the pK a of the PBA groups might decrease to <7.9 (see Fig. 4a, we can see the same trend in the <D h >/<D h > 0,pH versus the solution pH curves for both microgels.…”

“…[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Those results indicated that the pK a of the PBA groups might decrease to <7.9 (see Fig. In order to explain the shrinkage behavior of the microgels upon adding glucose, two main factors should be considered: one is related to the formation of glucose-boronate, 39 more stable than glucose-boronic acid, 40 which would induce a shift in the ionization equilibrium, increase the fraction of the charged phenylboronate and thus the Donnan potential (as well as the better polymer-solvent affinity) that favor the microgel swelling; [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] another is related to the formation of glucose-bisboronate complexes, which involves one glucose molecule (a) (b) bound simultaneously to two boronates and brings additional cross-linking junctions that favor the microgel shrinking. It is noted that the DAEAM molecule possesses both aromatic rings and tertiary amines.…”

“…In the early works, glucose oxidase and lectin were popular and already proved significant interests, but those natural receptors have severe disadvantages including the potential instability during use or sterilization. 17,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] A key issue for pPBA microgels concerns the tailoring of the glucose-responsive volume phase transition behavior of those microgels to meet the criteria of respective applications. 18 This has led to considerable interest in developing glucose-responsive polymer gels based on poly(phenylboronic acid) (pPBA).…”

“…It is well known that the binding of glucose to form the glucoseboronate complex (charged), 39 more stable than the glucoseboronic acid complex (uncharged), 40 can increase the ionization degree on the microgels and builds up a Donnan potential; the complexation can also change the polymer-solvent affinity (at neutral state, PBA has a hydrophobic character, but becomes more hydrophilic upon complexation). [21][22][23][24][25] However, it should be noted that those pPBA (micro)gels reported previously [7][8][9][10]13,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]41,43 can only undergo a fixed type (swelling and/or shrinking) of glucose-responsive volume phase transition behavior. In this respect, most pPBA microgels that undergo this complexation will swell when glucose concentration increases.…”

Stimuli‐responsive delivery of therapeutics for diabetes treatment

“…Ye et al reported a nanogel made of Con A interpenetrated in a chemically crosslinked network of poly( N ‐isopropylacrylamide) (poly(NIPAM)) . The semi‐interpenetrating‐structured nanogels can swell and become stable in less than 1 s after adding glucose over a concentration range of 50 μM to 20.0 mM at a physiological pH of 7.4.…”