A new boronate ester-based crosslinking strategy allows the design of nonswelling and long-term stable dynamic covalent hydrogels

Abstract

Dynamic hydrogels are viscoelastic materials that can be designed to be self-healing, malleable, and injectable, making them particularly interesting for a variety of biomedical applications. For the design of dynamic...

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“…The stiff formulation maintained a solid-like behavior over a larger range of shear rates, suggesting that the molecular weight, polymer content and crosslinking density play a role in the rheological properties of HA-based boronate ester hydrogels, as previously reported. [30] We further confirmed the shear-thinning behavior of the two hydrogel formulations with shear rate ramp experiments (Figure 2d,e). To validate the use of these dynamic hydrogels for bioprinting, we then evaluated their ability to flow upon stress and to recover their mechanical properties using alternated stress sweep tests (alternating 1 and 1000 Pa).…”

“…Polysaccharide Modifications-Synthesis of HA-wPBA: HA-wPBA was synthesized as previously described with minor modifications. [30] Briefly, 100 mg of sodium hyaluronate (HA) of 100 or 200 kDa) were dissolved at 10 mg.mL −1 in MES buffer (pH = 5.5), under stirring and at room temperature. After complete dissolution, DMT-MM (137.9 mg [2 eq] for HA 100-kDa HA; 69 mg [1 eq] for 200-kDa HA) was added and allowed to react for 30 min.…”

“…The degree of substitution of HA-wPBA was determined by 1 H NMR (400 MHz, D 2 O): the N-acetyl group of HA (3 protons at 2.1 ppm) served as a reference to quantify the relative amount of grafted wPBA (4 protons at 7.5-8 ppm), as previously reported. [30] Polysaccharide Modifications-Synthesis of HA-Glucamine: HAglucamine was synthesized as previously described with minor modifications. [30] Briefly, 100 mg of HA (100 or 200 kDa) was dissolved at 10 mg.mL −1 in MES buffer (pH = 5.5) at room temperature while stirring.…”

Phenylboronate-salicylate ester cross-linked self-healing hydrogel composed of modified hyaluronan at physiological pH

“…6 Numerous flexible hydrogels formed via boronate/diol ester cross-linking under physiological pH conditions have been developed till now. [7][8][9][10][11][12][13][14][15] In particular, injectable hydrogels based on boronate esters have good potential in clinical applications. 16,17 For instance, the hydrogel formed using boronate esters exhibited effectiveness in the treatment of brain lesions in small animal models.…”

“…10,11 Amino sugars such as fructosamine can be easily modified into polymers with carboxyl groups in a single step. 9,12,13 However, some amino sugars including fructosamine are too expensive to be utilised in the synthesis of diol-modified polymers on a practical scale. Therefore, diol-modified polymers for the formation of boronate esters are required that can be easily and inexpensively prepared in one step.…”