Biomimetic adhesive containing nanocomposite hydrogel with enhanced materials properties

Abstract

Chemically crosslinked polyacrylamide (PAAm) nanocomposite hydrogels were prepared with inorganic nano-silicate, Laponite, and dopamine methacrylamide (DMA). DMA consists of a biomimetic adhesive side chain covalently linked to a polymerizable methacrylate monomer. Copolymerizing DMA into a PAAm hydrogel strongly enhanced the interfacial interaction between the polymer network and Laponite. Nanocomposite hydrogels demonstrated reduced water content and increased materials properties that were dependent on both the Laponite and DMA contents. While increasing Laponite content alone improved materials properties moderately, these improvements were drastically enhanced when DMA is incorporated as measured by both unconfined compression testing and oscillatory rheometry. DMA-containing nanocomposite hydrogels demonstrated increased stiffness as well as excellent energy dissipation capability. Nanocomposite hydrogels with relatively low DMA and Laponite contents (2 to 3 wt% for each) demonstrated maximum compressive stress, elastic modulus, toughness, and storage and loss moduli values that were over an order of magnitude higher than control gels.DMA-containing nanocomposite hydrogels also demonstrated improved fracture resistance to compressive loading, capable of repeated compressed to 80% strain without rest for over 10 times while exhibiting compressive stress of over 1.1 MPa. The catechol side chain of DMA likely formed strong physical bonds with Laponite, which can dissipate fracture energy while minimizing permanent damage to the network architecture.

Transfer Printing of Metallic Microstructures on Adhesion‐Promoting Hydrogel Substrates

“…This observation could be attributed to DMA groups in swollen P(HEMA-co -DMA) hydrogels that form transient physical crosslinks through π-π stacking that can be ruptured at high frequencies. [ 62 ] The viscoelastic behavior of P(HEMA-co -DMA) hydrogels in this study is consistent with previous reports of catechol-bearing hydrogels. [ 62,63 ] Taken together, the mechanical properties of P(HEMA) hydrogels are largely preserved despite incorporating DMA.…”

Microsphere‐Incorporated Hybrid Thermogel for Neuronal Differentiation of Tonsil Derived Mesenchymal Stem Cells

“…The biomimetic design of a system with appropriate mechanical and adhesive properties with enhanced cellular interactions are particularly important. [ 68,69 ] In the current study, we selected a hydrogel with a modulus of 800 Pa at 37 °C, whereas the modulus of brain tissue is in a range of 100-1000 Pa. [ 26 ] Minute control of the hydrogel modulus might affect the neuronal differentiation of the stem cell. [ 70,71 ] Investigation of the hydrogel in a broader range of gel modulus covering 100-10 000 Pa will lead to an optimization of the current system for neuronal differentiation.…”

Current Approaches to Designing Nanomaterials Inspired by Mussel Adhesive Proteins

“…To enhance the interfacial binding between the polymer network and nanoparticles, dopamine methacrylamide (DMA) was copolymerized into a poly(acrylamide) nanocomposite hydrogel containing nano-silicate, Laponite (Na 0.7+ (Mg 5.5 Li 0.3 Si 8 )O 20 (OH) 4 ) 0.7 ) [125]. The DMA-containing nanocomposite demonstrated materials properties (e.g., maximum compressive strength, toughness, and storage and loss moduli) that were an order of magnitude higher than for DMA-free gels.…”