Dual-Site Biomacromolecule Doped Poly(3, 4-Ethylenedioxythiophene) for Bosting Both Anticoagulant and Electrochemical Performances.

Poly(3, 4-ethylenedioxythiophene) (PEDOT) as a new generation of intelligent conductive polymers, is attracting much attention in the field of tissue engineering. However, its water dispersibility, conductivity, and biocompatibility are incompatible, which limit its further development. In this work, biocompatible electrode material of PEDOT doped with sodium sulfonated alginate (SS) which contains two functional groups of sulfonic acid and carboxylic acid per repeat unit of the macromolecule. The as dual-site doping strategy simultaneously boosts anticoagulant and electrochemical performances, for example, good hydrophilicity (water contact angle of 59.40°), well dispersibility (dispersion solution unstratified in 30 days), high conductivity (4.45 S m-1), and enhanced anticoagulant property (extended activated partial thrombin time value of 59.0 s), forming an adjustable PEDOT: biomacromolecule interface; this fills the technical gap of implantable bioelectronics in terms of coagulation and thrombosis risk. At the same time, the assembled all-in-one supercapacitor with anticoagulant properties is prepared by PEDOT: sodium sulfonated alginate as electrode material and sodium alginate hydrogel as electrolyte layer. The dual-site doping strategy provides a new opinion for the design and optimization of functional conductive polymers and its applications in implantable energy storage fields.

"Salting out" in Hofmeister Effect Enhancing Mechanical and Electrochemical Performance of Amide-based Hydrogel Electrolytes for Flexible Zinc-Ion Battery.

With the development of flexible and wearable electronic devices, it is a new challenge for polymer hydrogel electrolytes to combine high mechanical flexibility and electrochemical performance into one membrane. In general, the high content of water in hydrogel electrolyte membranes always leads to poor mechanical strength, and limits their applications in flexible energy storage devices. In this work, based on the "salting out" phenomenon in Hofmeister effect, a kind of gelatin-based hydrogel electrolyte membrane is fabricated with high mechanical strength and ionic conductivity by soaking pre-gelated gelatin hydrogel in 2 m ZnSO4 aqueous. Among various gelatin-based electrolyte membranes, the gelatin-ZnSO4 electrolyte membrane delivers the "salting out" property of Hofmeister effect, which improves both the mechanical strength and electrochemical performance of gelatin-based electrolyte membranes. The breaking strength reaches 1.5 MPa. When applied to supercapacitors and zinc-ion batteries, it can sustain over 7500 and 9300 cycles for repeated charging and discharging processes. This study provides a very simple and universal method to prepare polymer hydrogel electrolytes with high strength, toughness, and stability, and its applications in flexible energy storage devices provide a new idea for the construction of secure and stable flexible and wearable electronic devices.

Heparin-like anticoagulant polypeptides with tunable activity: Synthesis, characterization, anticoagulative properties and clot solubilities in vitro.

Due to the uncontrollable anticoagulant activity and limited source, Heparin, which is commonly used in clinical anticoagulation therapies, faces the risk of spontaneous bleeding and thrombocytopenia. Herein, a series of anionic poly(amino acid) s poly (l-Serine-ran-L-Glutamic acid-ran-L-Cysteine-SO3) (PSEC-SO3) were prepared by the controlled Ring Opening Polymerization (ROP) of N-Carboxyanhydrides (NCAs). The anticoagulant activities of PSEC-SO3 can be regulated by simply adjusting the feeding ratio of monomers. In vitro tests show that these polypeptides can effectively prolong the Activated Partical Thromboplastin Time (APTT) and inhibit Factor IIa and Factor Xa, but has no significant effect on Prothrombin Time (PT) and Thrombin Time (TT), which indicates that PSEC-SO3 mainly act on the intrinsic pathway. In summary, the activity-tunable heparin-like polypeptides are expected to have good application prospects in the anticoagulant field.

Biomimetic chitosan-graft-polypeptides for improved adhesion in tissue and metal.

Inspired by the mussel foot protein and chitosan-based macromolecular adhesives, a series of chitosan-graft-polypeptides were synthesized by ring-opening polymerization of three N-carboxyanhydrides (NCAs) - 3,4-dihydroxyphenylalanine-N-carboxyanhydride (DOPA-NCA), cysteine-NCA (Cys-NCA) and arginine-NCA (Arg-NCA) - using partial-NH2-protected chitosan as an initiator. These copolymers demonstrated good biodegradability and low cytotoxicity. The results of lap-shear adhesion test showed that the maximum lap-shear adhesion strength on the porcine skin and aluminum sheet were 195.97 ± 21.1 kPa and 3080 ± 320 kPa, respectively, and the maximum tensile adhesion strength on bone was 642.70 ± 61.1 kPa. The rat experiment in vivo showed that these copolymers exhibited good hemostatic performance and can promote the healing of skin wound and bone fracture. It is expected that thesecopolymeric adhesives will have broad applications in hemostasis and soft tissue adhesions.

All-in-one hyperbranched polypeptides for surgical adhesives and interventional embolization of tumors.

A series of hyperbranched, thermo-responsive and mussel-inspired polypeptides were synthesized and used for surgical adhesion, hemostasis and interventional embolization. These polypeptides showed excellent tissue-adhesive properties according to adhesive strength tests on porcine skin and bone in vitro, where the maximum lap-shear adhesion strength on porcine skin was 114.5 kPa and the maximum tensile adhesion strength on bone was 786 kPa. In vivo animal experiments indicated that these polypeptides exhibit superior hemostatic properties and healing effects in skin incisions and osteotomy gap; the skin incision healing and osteotomy gap remodeling were completed in all rats after 14 and 60 days, respectively. In vivo evaluation of the embolization ability of these polypeptides was performed on rabbit kidney models, resulting in successful occlusion of renal arteries, which led to gross ischemic changes in the embolized kidneys up to 16 days. A trial embolization procedure on H22 tumor-bearing rat models also confirmed the gelability of these polypeptides in tumor arteries, which might cause damage to embolized tumors. Therefore, these polypeptides are expected to be good candidates as surgical tissue adhesives, antibleeding materials, and effective embolic materials.