scholarly journals Self-Healing Injectable Polymer Hydrogel via Dynamic Thiol-Alkynone Double Addition Crosslinks

Author(s):  
bowen fan ◽  
Kai Zhang ◽  
Qian Liu ◽  
Rienk Eelkema

<p>Introduction of dynamic thiol-alkynone double addition crosslinks in a polymer network enable the formation of a self-healing injectable polymer hydrogel. A 4-arm polyethylene glycol (PEG) tetra-thiol star polymer is crosslinked by a small molecule alkynone via the thiol-alkynone double adduct, to generate a hydrogel network under ambient aqueous conditions (buffer pH=7.4 or 8.2, room temperature). The mechanical properties of these hydrogels can be easily tuned by varying the concentration of polymer precursors. Through the dynamic thiol-alkynone double addition crosslink, these hydrogels are self-healing and shear thinning, as demonstrated by rheological measurements, macroscopic self-healing and injection tests. These hydrogels can be injected through a 20G syringe needle and recover after extrusion. In addition, good cytocompatibility of these hydrogels is confirmed by cytotoxicity test. This work shows the application of a new type of dynamic covalent chemistry in the straightforward preparation of self-healing injectable hydrogels, which may find future biomedical applications such as tissue engineering and drug delivery.</p>

2020 ◽  
Author(s):  
bowen fan ◽  
Kai Zhang ◽  
Qian Liu ◽  
Rienk Eelkema

<p>Introduction of dynamic thiol-alkynone double addition crosslinks in a polymer network enable the formation of a self-healing injectable polymer hydrogel. A 4-arm polyethylene glycol (PEG) tetra-thiol star polymer is crosslinked by a small molecule alkynone via the thiol-alkynone double adduct, to generate a hydrogel network under ambient aqueous conditions (buffer pH=7.4 or 8.2, room temperature). The mechanical properties of these hydrogels can be easily tuned by varying the concentration of polymer precursors. Through the dynamic thiol-alkynone double addition crosslink, these hydrogels are self-healing and shear thinning, as demonstrated by rheological measurements, macroscopic self-healing and injection tests. These hydrogels can be injected through a 20G syringe needle and recover after extrusion. In addition, good cytocompatibility of these hydrogels is confirmed by cytotoxicity test. This work shows the application of a new type of dynamic covalent chemistry in the straightforward preparation of self-healing injectable hydrogels, which may find future biomedical applications such as tissue engineering and drug delivery.</p>


2020 ◽  
Vol 9 (6) ◽  
pp. 776-780 ◽  
Author(s):  
Bowen Fan ◽  
Kai Zhang ◽  
Qian Liu ◽  
Rienk Eelkema

RSC Advances ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 6620-6627
Author(s):  
Huan-Jung Wang ◽  
Yi-Zuo Chu ◽  
Chen-Kang Chen ◽  
Yi-Shun Liao ◽  
Mei-Yu Yeh

A new type of conductive interpenetrating polymer network hydrogel exhibited self-healing reversibility mechanically and electrically when cut and self-healed, making it possible to apply in soft and conformable electronics.


2020 ◽  
Vol 11 (38) ◽  
pp. 6157-6162
Author(s):  
Lue Xiang ◽  
Xianfeng Liu ◽  
Huan Zhang ◽  
Ning Zhao ◽  
Ke Zhang

A new type of thermoresponsive dynamic covalent polymer network was developed with excellent self-healable and recyclable properties based on a new thermoresponsive dynamic covalent chemistry between a para-quinone methide and thiol nucleophiles.


Author(s):  
Alessia Mazzarotta ◽  
Tania Maristella Caputo ◽  
Luca Raiola ◽  
Edmondo Battista ◽  
Paolo Antonio Netti ◽  
...  

The control of the three-dimensional (3D) polymer network structure is important for permselective materials when specific biomolecules detection is needed. Here we investigate conditions to obtain a tailored hydrogel network that combine both molecular filtering and molecular capture capabilities for biosensing applications. Along this line short oligonucleotide detection in a displacement assay is set within PEGDA hydrogels synthetized by UV radical photopolymerization. To provide insights on the molecular filter capability, diffusion studies of several probes (sulforhodamine G and dextrans) with different hydrodynamic radii were carried out using NMR technique. Moreover, fluorometric analyses of hybridization of DNA oligonucleotides inside PEGDA-hydrogels shed light on the mechanisms of recognition in 3D, highlighting that mesh size and crowding effect greatly impact of hybridization mechanism onto polymer network. Finally, we found the best probe density and diffusion transport conditions to allow the specific oligonucleotide capture and detection inside PEGDA-hydrogels for oligonucleotide detection and the filtering out of higher molecular weight molecules.


2021 ◽  
Author(s):  
Ryuji Kiyama ◽  
Takayuki Nonoyama ◽  
Sedlacik Tomas ◽  
Hiroshi Jinnai ◽  
Jian Ping Gong

Hydrogels are promising materials for several applications, including cell scaffolds and artificial load-bearing substitutes (cartilages, ligaments, tendons, etc.). Direct observation of the nanoscale polymer network of hydrogels is essential in understanding its properties. However, imaging of individual network strands at the molecular level is not achieved yet due to the lack of suitable methods. Herein, for the first time, we developed a novel mineral-staining method and network fixation method for transmission electron microscopy observation to visualize the hydrogel network in its unperturbed conformation with nanometer resolution. Surface network observation indicates that the length of surface dangling chains, which play a major role in friction and wetting, can be estimated from the gel mesh size. Moreover, bulk observations reveals a hierarchical formation mechanism of gel heterogeneity. These observations have the great potential to advance gel science by providing comprehensive perspective that link bulk gel properties with nanoscale.


2017 ◽  
pp. 1133-1164
Author(s):  
Snežana S. Ilić-Stojanović ◽  
Ljubiša B. Nikolić ◽  
Vesna D. Nikolić ◽  
Slobodan D. Petrović

The latest development in the field of smart hydrogels application as drugs carriers is shown in this chapter. Hydrogels are three-dimensional polymer network consisting of at least one hydrophilic monomer. They are insoluble in water, but in the excess presence of water or physiological fluids, swell to the equilibrium state. The amount of absorbed water depends on the chemical composition and the crosslinking degree of 3D hydrogel network and reaches over 1000% of the xerogel weight. Stimuli-responsive hydrogels exhibit significant change of their properties (swelling, color, transparency, conductivity, shape) due to small changes in the external environment conditions (pH, ionic strength, temperature, light wavelength, magnetic or electric fields, ultrasound, or a combination thereof). This smart hydrogels, with different physical and chemical properties, chemical structure and technology of obtaining, show great potential for application in the pharmaceutical industry. The application of smart hydrogels is very promising and at the beginning of the development and exploitation.


2020 ◽  
Vol 117 (14) ◽  
pp. 7606-7612 ◽  
Author(s):  
Xueyu Li ◽  
Kunpeng Cui ◽  
Tao Lin Sun ◽  
Lingpu Meng ◽  
Chengtao Yu ◽  
...  

Load-bearing biological tissues, such as muscles, are highly fatigue-resistant, but how the exquisite hierarchical structures of biological tissues contribute to their excellent fatigue resistance is not well understood. In this work, we study antifatigue properties of soft materials with hierarchical structures using polyampholyte hydrogels (PA gels) as a simple model system. PA gels are tough and self-healing, consisting of reversible ionic bonds at the 1-nm scale, a cross-linked polymer network at the 10-nm scale, and bicontinuous hard/soft phase networks at the 100-nm scale. We find that the polymer network at the 10-nm scale determines the threshold of energy release rateG0above which the crack grows, while the bicontinuous phase networks at the 100-nm scale significantly decelerate the crack advance until a transitionGtranfar aboveG0. In situ small-angle X-ray scattering analysis reveals that the hard phase network suppresses the crack advance to show decelerated fatigue fracture, andGtrancorresponds to the rupture of the hard phase network.


Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1416 ◽  
Author(s):  
Pejman Heidarian ◽  
Abbas Z. Kouzani ◽  
Akif Kaynak ◽  
Ali Zolfagharian ◽  
Hossein Yousefi

It is an ongoing challenge to fabricate an electroconductive and tough hydrogel with autonomous self-healing and self-recovery (SELF) for wearable strain sensors. Current electroconductive hydrogels often show a trade-off between static crosslinks for mechanical strength and dynamic crosslinks for SELF properties. In this work, a facile procedure was developed to synthesize a dynamic electroconductive hydrogel with excellent SELF and mechanical properties from starch/polyacrylic acid (St/PAA) by simply loading ferric ions (Fe3+) and tannic acid-coated chitin nanofibers (TA-ChNFs) into the hydrogel network. Based on our findings, the highest toughness was observed for the 1 wt.% TA-ChNF-reinforced hydrogel (1.43 MJ/m3), which is 10.5-fold higher than the unreinforced counterpart. Moreover, the 1 wt.% TA-ChNF-reinforced hydrogel showed the highest resistance against crack propagation and a 96.5% healing efficiency after 40 min. Therefore, it was chosen as the optimized hydrogel to pursue the remaining experiments. Due to its unique SELF performance, network stability, superior mechanical, and self-adhesiveness properties, this hydrogel demonstrates potential for applications in self-wearable strain sensors.


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