Dopamine-melanin, polydopamine molecular assembly by cation-π bonds.

A new insect-cuticle- and fruit-browning-mimetic film exhibiting simultaneous self-healing and self-sealing properties only by ambient oxygen without external stimuli is developed. The film is formed at the liquid/air interface via crosslinking of phenolic compounds and poly(amine) chains. The film can be self-healed over a hundred times under ambient air at room temperature without exogenous materials and stimuli.

New binder concepts have lately demonstrated improvements in the cycle life of high-capacity silicon anodes. Those binder designs adopt adhesive functional groups to enhance affinity with silicon particles and 3D network conformation to secure electrode integrity. However, homogeneous distribution of silicon particles in the presence of a substantial volumetric content of carbonaceous components (i.e., conductive agent, graphite, etc.) is still difficult to achieve while the binder maintains its desired 3D network. Inspired by mucin, the amphiphilic macromolecular lubricant, secreted on the hydrophobic surface of gastrointestine to interface aqueous serous fluid, here, a renatured DNA-alginate amphiphilic binder for silicon and silicon-graphite blended electrodes is reported. Mimicking mucin's structure comprised of a hydrophobic protein backbone and hydrophilic oligosaccharide branches, the renatured DNA-alginate binder offers amphiphilicity from both components, along with a 3D fractal network structure. The DNA-alginate binder facilitates homogeneous distribution of electrode components in the electrode as well as its enhanced adhesion onto a current collector, leading to improved cyclability in both silicon and silicon-graphite blended electrodes.

polymers, but they are water-insoluble, organic-solvent basis glues. [10,11] Despite recent novel approaches in adhesives using nanoparticles, [12] stretchable gels, [13] and numerous bioadhesive studies summarized in reviews, [3,4] bioinspired waterborne and biocompatible adhesives showing superglue-like adhesion strength have not been reported. Phenol-amine synergy is also found in insect exoskeletons in which aminerich polymer backbones are cross-linked by phenolic compounds by N-acetyldopamine, N-β-alanyl-dopamine, and dopamine. [14,15] The key biochemistry in sclerotization (i.e., hardening) processes is crosslinking of amine-rich polymers via phenol-quinone involved oxidative reactions. Being different from mechanically weak adhesive materials inspired by marine organisms mentioned above, Young's moduli of exoskeletons are extremely high exhibiting 1-20 GPa, [16] which is similar to ones of common plastics including nylon (2-4 GPa), poly(ethylene terephthalate) (PET) (2-2.7 GPa), and polystyrene (3-3.5 GPa). So far, no studies attempting uses of insect sclerotization process as a new curing strategy in adhesives are reported. We hypothesized that combining: 1) adhesive properties originated from phenols and 2) insect exoskeleton-like hard material properties inspired by phenol-amine phenolamine crosslinking would result in biomimetic superglues. To achieve this goal, the Exoskeletons of insects formed by sclerotization processes exhibit superstrong properties in moduli. Here, it is demonstrated that mimicking the sclerotization process using phenol and polyamine molecules unexpectedly results in a 100% ecofriendly, biocompatible waterborne superglue. Oxygen presented in air and dissolved in water acts as an initiator producing phenolic radical/quinone for superglue curing. Despite synthesis-free uses of water, phenol, and polyamine, its adhesion strength is comparable to commercial epoxy glue showing >6 MPa in lap shear strength. The phenol-amine superglue bonds to various substrates including ceramics, woods, fabrics, plastics, metals, and importantly biological tissues. Due to strong adhesion, the superglue effectively seals wounds within a few seconds, and, due to its waterborne nature, no harmful respiratory effect is observed because of any release of volatile organic compounds. The easy, cost-effective preparation of the phenol-amine superglue can revolutionize varieties of industrial, biomedical, daily life processes. Phenol-amine synergy found in marine mussels or tunicates inspires researchers to develop material-independent surface chemistry and medical soft adhesives. [1] Examples include polydopamine coatings in surface chemistry [2] and catechol-and gallol-tethered soft adhesives. [3-9] Adhesion forces observed from bioinspired adhesive polymers are generally weak in the range of kPa: hyaluronic acid-catechol (0.8 kPa), [5] poly(glutamic acid)-catechol (26.1-58.2 kPa), [6] poly(methacrylamide)-catechol (10-300 kPa), [7] and chitin-gallol (215 kPa). [8] A few studies reported adhesion in MPa ord...

The intraperitoneal (IP) cavity is the largest fluid-filled space in the body and contains important organs. Although peritoneal fluid from the abdominal cavity lubricates and allows organ motion, this fluid also effectively prevents polymeric material implantation. Anastomotic leakage after surgery has been reported but few sealing methods have been developed. Herein, a fluidresistant adhesive called IP patch is reported that seals intestinal neo-anastomosis sites, preventing anastomotic leakage after colorectal surgery. The bursting pressure, which is the most important index of the degree of healing after colorectal anastomosis surgery, is measured from an IP patch applied to rats (188.3 ± 14.5 mmHg) and is highly similar to the pressure observed from normal tissue (210.2 ± 22.9 mmHg). Additionally, IP patches can act as unprecedented local drug reservoirs due to the aforementioned tissue adhesive property. Drug-loaded IP patches successfully treated multiple-site occurrence of small peritoneal cancerous colonies. The anticancer drug-loaded IP patches are applied to potential risk regions for recurrent and metastasized cancer in the IP cavity after the resection of peritoneal solid tumors. Thus, the multifunctionality of IP patches can be usefully exploited as an adhesive biomaterial that works effectively in difficult-to-treat diseases observed in IP environments.

Hemostatic materials have been studied to minimize bleeding time. Recently, polyphosphate (polyP) have received attention as potential hemostatic compounds, which are released from activated platelets. Long polyP chains are essential to form thick fibrin clots. Herein, chitosan is functionalized by covalently tethering phosphate groups to mimic polyP. It is hypothesized that utilizing a known hemostatic polysaccharide, chitosan, and tethering phosphate groups to mimic polyP's functionality show synergistic effect in hemostasis. Five different phosphorylated chitosan conjugates (Chi-Ps), s-Chi-7P, s-Chi-28P, s-Chi-74P, is-Chi-29P, and is-Chi-56P are prepared, where "s" indicates water soluble Chi-Ps and "is" represents water insoluble Chi-Ps. Unexpectedly, an important carbon in D-glucosamine is found, which determines chitosan solubility. Phosphate groups conjugated to C6 carbon resulted in water soluble Chi-P, but conjugation to C3 group exhibited water insoluble behavior. Hemostasis capability showed a positive correlation with the degree of phosphate conjugations regardless of water solubility of Chi-P.

Polyphenol materials have rapidly emerged as bioadhesives. However, nearly all exhibit low adhesion strength compared to commercial glues. In article number 2002118, Seung‐Woo Cho, Haeshin Lee, and co‐workers show that phenolamine can exhibit adhesive strength >6 MPa, comparable to commercial epoxy glues. The advantage of the phenolamine bioglue is its 100% water basis. It effectively seals various substrates including ceramics, wood, fabrics, plastics, metals, and even wounded skin without any harmful effects. Therefore, these findings are promising in both industrial and biomedical applications.

In article number 1900495, Haeshin Lee, Jun Seok Park, and co‐workers demonstrate a body fluid‐resistant intraperitoneal patch inspired by mussel adhesion. The patch seals newly generated leaking sites after colorectal surgery. Also, the patch releases anti‐cancer drugs that suppress recurrent tumors and provides an effective adhesive platform for difficult‐to‐treat diseases in intraperitoneal environments.