A robust super-tough biodegradable elastomer engineered by supramolecular ionic interactions

Abstract

Alginate-based supramolecular ionic polyurethanes (ASPUs) as mechanically tunable biomaterials with high strength and toughness in both dry and hydrated states are developed under metal-free conditions. The Young's modulus and tensile strength of ASPUs are tuned from 30 to 100 MPa, and 20 to 50 MPa, respectively. Interestingly, the ASPUs exhibit a small hysteresis loop, minimal loss of tensile strength and minimal creep deformation after 100 repetitive cycles which makes them of use for engineering of load-bearing tissues. This is the first report that describes a linear PU can resist a large number of cyclic stresses without significant stretching. These bio-based elastomers engineered by ionic interactions are biocompatible and biodegradable. The ASPUs demonstrate a similar in vivo degradation rate compared to polycaprolactone (PCL). These biomaterials also demonstrate a rapid self-healing and recovery after rupture, and have a linear biodegradation profile. Furthermore, histological examination of subcutaneous transplanted ASPUs after five months reveals low immunological response and low fibrosis.

Facile synthesis of novel elastomers with tunable dynamics for toughness, self-healing and adhesion

“…The 0 0.1 maximum fracture energy is as high as 20 kJ/m 2 , comparable to that of natural rubber and recently developed tough elastomers. [10,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][32][33][34] Furthermore, the short Kuhn segment relaxation times give rise to high mobility of polymer chains, affording the materials to heal the fractured surfaces after cutting and adhere on the different substrates at room temperature.…”

“…[2] Poor network concept, [7][8][9][10] and of reversible sacrificial bonds by ionic interactions, hydrogen bonds, etc. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] These approaches, however, usually need complicated synthesis processes, which limits their applicability for wide use where simple processing, cost effective, ecofriendly, scalability are required. In this work, we intend to develop a series of tough, selfhealing and adhesive elastomers with tunable mechanical properties by simple one-step synthesis without using solvents.…”

Towards Dynamic but Supertough Healable Polymers through Biomimetic Hierarchical Hydrogen‐Bonding Interactions

“…Extrinsic healing relies on preliminarily embedded microcapsules or vascular networks, which allow the materials to be healed for only limited times . Intrinsically healable polymers offer repeatable self‐healing based on the self‐assembly layer‐by‐layer technique or synthetic strategies via supramolecular reversible interactions, such as host–guest interactions, metal–ligand coordination, ionic interactions, and hydrogen bonding . Hydrogen bonding is ubiquitous in biomolecules, imparting specific physiological or biochemical functionality to structures such as the skeletal muscle protein titin .…”

Self‐Healing Biomaterials: From Molecular Concepts to Clinical Applications

“…Polymeric biomaterial films which self‐heal based on electrostatic forces have also been developed. Daemi et al developed biocompatible and biodegradable alginate‐based polyurethane elastomers with self‐healing capability for applications in tissue engineering. An isocyanate (NCO)‐endcapped PCL‐urethane polymer was reinforced through crosslinking with alginate, using NCO‐hydroxyl chemistry.…”