Multi-crosslinking hydrogels with robust bio-adhesion and pro-coagulant activity for first-aid hemostasis and infected wound healing

Bio-adhesive polysaccharide-based hydrogels have attracted much attention in first-aid hemostasis and wound healing for excellent biocompatibility,antibacterial property and pro-healing bioactivity.Yet,the inadequate mechanical properties and bio-adhesion limit their applications.Herein,based on dynamic covalent bonds,photo-triggered covalent bonds and hydrogen bonds,multifunctional bio-adhesive hydrogels comprising modified carboxymethyl chitosan,modified sodium alginate and tannic acid are developed.Multi-crosslinking strategy endows hydrogels with improved strength and flexibility simultaneously.Owing to cohesion enhancement strategy and self-healing ability,considerable bio-adhesion is presented by the hydrogel with a maximal adhesion strength of 162.6 kPa,12.3-fold that of commercial fibrin glue.Based on bio-adhesion and pro-coagulant activity(e.g.,the stimulative aggregation and adhesion of erythrocytes and platelets),the hydrogel reveals superior hemostatic performance in rabbit liver injury model with blood loss of 0.32 g,only 54.2%of that in fibrin glue.The healing efficiency of hydrogel for infected wounds is markedly better than commercial EGF Gel and Ag+Gel due to the enhanced antibacterial and antioxidant properties.Through the multi-crosslinking strategy,the hydrogels show enhanced mechanical properties,fabulous bio-adhesion,superior hemostatic performance and promoting healing ability,thereby have an appealing application value for the first-aid hemostasis and infected wound healing.

Bio-Adhesives Combined with Lotus Leaf Fiber to Prepare Bio-Composites for Substituting the Plastic Packaging Materials

This work was aim to prepare a packing material from natural resources to reduce the environment pollution caused by plastics.Four bio-adhesives(guar gum,sodium alginate,agar and chitosan)were combined with lotus leaf fibers to prepare degradable composites,respectively.The mechanical properties,moisture absorption profiles and the thermal conductivity of the composites were studied and the cross section morphology and the thermal properties of the composites were analyzed.The Fourier-transform infrared spectroscopy(FTIR)results showed that the polar groups such as–OH and–COO^(–)in bio-adhesives can form hydrogen bond with–OH in lotus leaf fibers to connect the two components.The combination of agar and lotus leaf fiber was good,and their composite had the best mechanical properties,with the tensile strength,flexural strength and impact strength of 2.05,5.9 MPa and 4.29 kJ·m_(−2),respectively,and the composite had a low moisture absorption profile,and the equilibrium moisture absorption rate was 32.32%.The lotus leaf fiber/agar composite(LAC)had an excellent comprehensive performance and it was non-toxic,degradable and thermal insulating,which indicated that it had the potential to use in packaging field to substitute plastics.

A multi-functional binder for high loading sulfur cathode

Lithium sulfur(Li-S)batteries are the promising power sources,but their commercialization is significantly impeded by poor energy-storage functions at high sulfur loading.Here we report that such an issue can be effectively addressed by using a mussel-inspired binder comprised of chitosan grafted with catecholic moiety for sulfur cathodes.The resulting sulfur cathodes possess a high loading up to 12.2 mg cm-2 but also exhibit one of the best electrochemical properties among their counterparts.The excellent performances are attributed to the strong adhesion of the binder to sulfur particles,conducting agent,current collector,and polysulfide.The versatile adhesion effectively increases the sulfur loading,depresses the shuttle effect,and alleviates mechanical pulverization during cycling processes.The present investigation offers a new insight into high performance sulfur cathodes through a bio-adhesion viewpoint.

Bioinspired-Interpenetrating Network (IPNs) Hydrogel (BIOF-INPs) and TMD <i>in Vitro</i>: Bioadhesion, Drug Release and Build in Free Radical Detection and Defense

In this work, Bioactive-functionalized interpenetrating network (IPNs) hydrogel (BIOF-INPs) were prepared and investigated in vitro for the free radical detection/defense, therapeutic release as well as shear bond strength to dentine, ability to re-mineralize surface of the dentin after application of these bio-inspired materials using a biologically inspired mineralization process in vitro as well as investigating antimicrobial properties of the BIOF-INPs against S. aureous. The aim of this investigation was to evaluate the suitability and flexibility of the designer materials to act as an “in vitro” probe to gain insights into molecular origin of TMD and associated disorders.

Mesoporous silica nanoparticles with chiral pattern topological structure function as“antiskid tires”on the intestinal mucosa to facilitate oral drugs delivery

The weak adhesion between nanocarriers and the intestinal mucosa was one of the main reasons caused the failure in oral delivery.Inspired by the“antiskid tires”with complex chiral patterns,mesoporous silica nanoparticles AT-R@CMSN exhibiting geometrical chiral structure were designed to improve the surface/interface roughness in nanoscale,and employed as the hosting system for insoluble drugs nimesulide(NMS)and ibuprofen(IBU).Once performing the delivery tasks,AT-R@CMSN with rigid skeleton protected the loaded drug and reduced the irritation of drug on gastrointestinal tract(GIT),while their porous structure deprived drug crystal and improved drug release.More importantly,AT-R@CMSN functioned as“antiskid tire”to produce higher friction on intestinal mucosa and substantively influencedmultiple biological processes,including“contact”,“adhesion”,“retention”,“permeation”and“uptake”,compared to the achiral S@MSN,thereby improving the oral adsorption effectiveness of such drug delivery systems.By engineering AT-R@CMSN to overcome the stability,solubility and permeability bottlenecks of drugs,orally administered NMS or IBU loaded AT-R@CMSN could achieve higher relative bioavailability(705.95%and 444.42%,respectively)and stronger anti-inflammation effect.In addition,AT-R@CMSN displayed favorable biocompatibility and biodegradability.Undoubtedly,the present finding helped to understand the oral adsorption process of nanocarriers,and provided novel insights into the rational design of nanocarriers.

Biomimetic microstructural scaffolds and their applications in tissue engineering

The dynamic structures of extracellular matrix regulate cell behaviors by providing three-dimension ecological niche and mechanical cues.Under the progress of both surface patterning and biomaterials,the cues of micro-and nanoscale topography on microstructural scaffold biomaterials are increasingly recognized as decisive factors of biomimetic materials.In this review,we provide an overview of the recent progress of biomimetic microstructured scaffolds,including advances in their biomimetic manufacturing technology,functionality,potential applications and future challenges.We highlight recent progress in the fabrication of microstructured scaffold materials with various biological and physicochemical characteristics of native extracellular matrix.The recent key advances of microstructured scaffold for tissue engineering,bio-adhesive,antibacterial and biosensing applications were offered.Eventually,we summarize by offering our perspective on this fast-growing field.

Multifunctional electroactive bio-adhesive for robustly-integrated wound therapy and postoperative wound-status warning and assessment

Wound abnormalities such as secondary wound laceration and inflammation are common postoperative health hazards during clinical procedures.The continuous treatment,healing induction,and real-time visualization of wound status and complications,including wound re-tearing,inflammation,and morphology,are key focal points for comprehensive healthcare.Herein,an on-demand quadruple energy dissipative strategy was proposed for the nanoengineering of a physically and chemically synergistic double-layer gelatin-based bio-adhesive(DLGel)by combining a multi-network adhesive layer and a versatile electroactive energy dissipative layer based on contrivable interlocking micro-pillar arrays and crosslinked polymer chains.The subtly multiple energy dissipation designs enable DLGel with robust adhesive strength to omnipotently wet and dynamic tissue,providing a basis for reliable wound closure.DLGel achieves comprehensive wound-healing induction through electrical stimulation and possesses reversible underwater light/thermal adhesion,excellent hemostatic performance,outstanding antimicrobial properties,and self-repair capability.Furthermore,a novel deep-learning strategy is creatively established to respond to mechanical deformation due to wound anomalies.This strategy translates biological information into visual graphics,providing real-time early warning and assessment of postoperative wound-abnormality/-morphology,such as laceration,inflammation,and necrosis.Therefore,DLGel and its associated signal collection and processing protocol enable the integration of reliable wound closure,wound healing,and real-time postoperative wound-status warning and assessment within the unobservable and undetectable“black box”regions in a context of non-clinical comprehensive therapy.

Pharmacokinetics and correlation between in vitro release and in vivo absorption of bio-adhesive pellets of panax notoginseng saponins

The present study was designed to prepare and compare bio-adhesive pellets of panax notoginseng saponins(PNS) with hydroxy propyl methyl cellulose(HPMC), chitosan, and chitosan : carbomer, explore the influence of different bio-adhesive materials on pharmacokinetics behaviors of PNSbio-adhesive pellets, and evaluate the correlation between in vivo absorption and in vitro release(IVIVC). In order to predict the in vivo concentration-time profile by the in vitro release data of bio-adhesive pellets, the release experiment was performed using the rotating basket method in p H 6.8 phosphate buffer. The PNS concentrations in rat plasma were analyzed by HPLC-MS-MS method and the relative bioavailability and other pharmacokinetic parameters were estimated using Kinetica4.4 pharmacokinetic software. Numerical deconvolution method was used to evaluate IVIVC. Our results indicated that, compared with ordinary pellets, PNS bio-adhesive pellets showed increased oral bioavailability by 1.45 to 3.20 times, increased Cmax, and extended MRT. What's more, the release behavior of drug in HPMC pellets was shown to follow a Fickian diffusion mechanism, a synergetic function of diffusion and skeleton corrosion. The in vitro release and the in vivo biological activity had a good correlation, demonstrating that the PNS bio-adhesive pellets had a better sustained release. Numerical deconvolution technique showed the advantage in evaluation of IVIVC for self-designed bio-adhesive pellets with HPMC. In conclusion, the in vitro release data of bio-adhesive pellets with HPMC can predict its concentration-time profile in vivo.

Intelligent structured nanocomposite adhesive for bioelectronics and soft robots

The remarkable functionality of biological systems in detecting and adapting to various environmental conditions has inspired the design of the latest electronics and robots with advanced features.This review focuses on intelligent bio-inspired strategies for developing soft bioelectronics and robotics that can accommodate nanocomposite adhesives and integrate them into biological surfaces.The underlying principles of the material and structural design of nanocomposite adhesives were investigated for practical applications with excellent functionalities,such as soft skin-attachable health care sensors,highly stretchable adhesive electrodes,switchable adhesion,and untethered soft robotics.In addition,we have discussed recent progress in the development of effective fabrication methods for micro/nanostructures for integration into devices,presenting the current challenges and prospects.