Self-Healing Behavior of Polymer/Protein Hybrid Hydrogels

Abstract

The paper presents the viscoelastic properties of new hybrid hydrogels containing poly(vinyl alcohol) (PVA), hydroxypropylcellulose (HPC), bovine serum albumin (BSA) and reduced glutathione (GSH). After heating the mixture at 55 °C, in the presence of GSH, a weak network is formed due to partial BSA unfolding. By applying three successive freezing/thawing cycles, a stable porous network structure with elastic properties is designed, as evidenced by SEM and rheology. The hydrogels exhibit self-healing properties when the samples are cut into two pieces; the intermolecular interactions are reestablished in time and therefore the fragments repair themselves. The effects of the BSA content, loaded deformation and temperature on the self-healing ability of hydrogels are presented and discussed through rheological data. Due to their versatile viscoelastic behavior, the properties of PVA/HPC/BSA hydrogels can be tuned during their preparation in order to achieve suitable biomaterials for targeted applications.

Bioinspired Hydrogels as Platforms for Life-Science Applications: Challenges and Opportunities

“…There is a variety of strategies to develop materials with properties attractive in many biomedical applications. Thus, the hydrogel strength can be tuned from their formulation, from very soft to very hard structure networks, suitable for the targeted applications: from injectable hydrogels [26,34,35] for tissue filling and restoration [3,[36][37][38], biomaterials for rapid hemostasis [39], wound healing [39,40], and drug delivery carriers [35,41] to robust and tough hydrogels required for load-bearing applications (artificial cartilage, muscle) [34] and smart biomaterials for tissue engineering [4,24,42] or advanced technological applications [14,43,44].…”

“…The supramolecular self-assembly offers the possibility to obtain a variety of biomaterials for improving everyday life with a minimum impact to environment. Thus, different polymeric architectures and morphologies were designed as drug carriers for controlled release and optimized targeting [6,41,58,59,62,63], wound healing materials [24,39,40], tissue engineering [4,5,[36][37][38]46,52,57], healthy food [19], or eco-friendly packaging [48,61]. In addition to the functional performances, the morphological stability and structural integrity of biomaterials determine their in vivo effectiveness [24][25][26][27][28][29]46,53,54].…”

“…Thus, the approach considered for a hydrogel design, depending on the targeted application, considers the relationship between the viscoelastic properties and physico-chemical structure of the network (hydrogel composition, crosslinking density, mesh size of the network, the frequency and strength of different interactions). Different rheological tests, such as temperature [134], time [24,134], deformation or frequency sweep [24,27,35,40,135], creep and recovery [27][28][29]134,136], continuous shear measurements [27,40] are often required. The usual rheological tests, in correlation with the hydrogel structure, are presented in a recent review [137].…”

“…PVA-based hydrogels provide also promising platforms with a broad range of tunable mechanical properties [24,27,40,41,49,92,96,129,132,134,[142][143][144][145]. By choosing the proper method of preparation and the optimum composition, the mechanical properties of hydrogels can be modulated over a large window: tensile strength from 10 kPa to 10 MPa, toughness from 100 J/m 2 to 100 MJ/m 2 , elongation in the range 100-2100%, and elastic modulus from 1 kPa to 2.5 MPa.…”

“…Inspired by nature, the great challenge is now to create self-healing hydrogels that present the ability to form spontaneously new physical or chemical bonds when some existing bonds are disrupted, preserving the structural integrity and extending the service lifetime in various applications [24][25][26][27][28][29].…”