Natural biopolymers derived hydrogels with injectable,self-healing,and tissue adhesive abilities for wound healing

Developing a biocompatible and multifunctional adhesive hydrogel with injectability and self-healing ability for promoting wound healing is highly anticipated in various clinical applications.In this paper,we present a novel natural biopolymer-derived hydrogel based on the aldehyde-modified oxidized guar gum(OGG)and the carboxymethyl chitosan(CMCS)for efficiently improving wound healing with the encapsulation of vascular endothelial growth factor(VEGF).As the hydrogels are synthesized via the dynamically reversible Schiff base linkages,it is imparted with excellent self-healing ability and good shear thinning behavior,which make the hydrogel be easily and conveniently injected through a needle.Besides,the physiochemical properties,including porous structure,mechanical strength and swelling ratio of the hydrogel can be well controlled by regulating the concentrations of the OGG.Moreover,the hydrogel can attain strong adhesion to the tissues at physiological temperature based on the Schiff base between the aldehyde group on the hydrogel and the amino group on the tissue.Based on these features,we have demonstrated that the VEGF encapsulated hydrogel can adhere tightly to the defect tissue and improve wound repair in the rat model of defected skin by promoting cell proliferation,angiogenesis,and collagen secretion.These results indicate that the multifunctional hydrogel is with great scientific significance and broad clinical application prospects.

3D-printed fish gelatin scaffolds for cartilage tissue engineering

Knee osteoarthritis is a chronic disease caused by the deterioration of the knee joint due to various factors such as aging,trauma,and obesity,and the nonrenewable nature of the injured cartilage makes the treatment of osteoarthritis challenging.Here,we present a three-dimensional(3D)printed porous multilayer scaffold based on cold-water fish skin gelatin for osteoarticular cartilage regeneration.To make the scaffold,cold-water fish skin gelatin was combined with sodium alginate to increase viscosity,printability,and mechanical strength,and the hybrid hydrogel was printed according to a pre-designed specific structure using 3D printing technology.Then,the printed scaffolds underwent a double-crosslinking process to enhance their mechanical strength even further.These scaffolds mimic the structure of the original cartilage network in a way that allows chondrocytes to adhere,proliferate,and communicate with each other,transport nutrients,and prevent further damage to the joint.More importantly,we found that cold-water fish gelatin scaffolds were nonimmunogenic,nontoxic,and biodegradable.We also implanted the scaffold into defective rat cartilage for 12 weeks and achieved satisfactory repair results in this animal model.Thus,cold-water fish skin gelatin scaffolds may have broad application potential in regenerative medicine.

One-step and wash-free multiplexed immunoassay platform based on bioinspired photonic barcodes

Multiplex,rapid and accurate virus quantification plays a great value in biomedical detection.Here,a novel one step,wash-free immunoassay platform based bioinspired PhC barcodes for multiplexed virus quantification was explored.PhC barcodes were decorated with PDA by self-polymerization of DA,thus this nanocomposite hybridized PhC barcodes facilitated the adsorption of FITC labelled antibodies and quenched itself photolumines-cent,allowing a fast responsive composite platform.In the presence of target analyte,the FITC-labelled detection antibody was released from the surface of PDA decorated microcarrier to specifically bind to the target ana-lyte,thus recovered the photoluminescence.In addition,the PhC microcarrier was enabled to carry out various color barcode for different targets detection though tuning internal periodic structures.Based on these excellent performances of the nanocomposite barcode,this method can not only capture H1N1,H5N1,SARS-CoV-2 si-multaneously with rapid,accuracy but also accomplish multiplex quantification detection with high-sensitivity.Furthermore,our developed platform was also achieved with high-sensitivity and high-specificity through the verification of clinical samples,thus laying out a new avenue for multiplex virus detection in clinical diagnosis.

Biomimetic selenium nanosystems for infectious wound healing

Bacteria-related wound infection and healing have been a major issue for patients and health-care systems for decades.The rise and evolution of effective treatment will result in significant benefits to human beings.In ad-dition to standard antibacterial drugs,a combination of nanoparticles(NPs)and biological membranes is widely applied as a novel antibacterial agent against infectious pathogens.In this paper,the red blood cell membrane-encapsulated selenium nanoparticles(R-SeNPs)were fabricated for infectious wound healing.The stability,the immune evading capability,and the internal circulation time of the R-SeNPs were notably enhanced compared with those of bare selenium nanoparticles(SeNPs).Moreover,in vivo studies demonstrated the outstanding per-formance of the R-SeNPs in infectious wound healing.The biomimetic selenium nanosystem demonstrated the benefits of the combination of nanotechnology and bionics design and will contribute to wound healing in the future.

微流控制备集成液体金属的超弹纤维用于可穿戴电子设备

液体金属作为室温下呈现出液态的金属是推动未来发展的新材料.目前已有不少研究基于液体金属开发具有新功能的材料、设备和器件,并不断优化它们在实际应用中的性能.本文提出了集成液体金属的超弹纤维,其展现出独特的性质,并有望被应用于可穿戴电子设备.利用程式化微流控纺丝和灌注技术,可以连续地制备具有超弹聚氨酯外壳和液体金属内核的纤维材料.微流控技术能够对微量的液体进行方便又精确的控制,该方法制备的纤维材料具有可调节的结构形貌,并具备不同的导电能力.将制备所得纤维进一步集成到弹性薄膜中,所构成的复合薄膜材料由于发生形变而表现出电阻的变化,因此能够用于压力传感器和运动指示器.此外,利用液体金属卓越的性质,能够实现电磁和电热等不同形式能量的转换.所制备的集成液体金属的超弹纤维为可穿戴电子设备、液体金属集成材料的研究开辟了新思路.

Morphological Hydrogel Microfibers with MXene Encapsulation for Electronic Skin

Electronic skins with distinctive features have attracted remarkable attention from researchers because of their promising applications in flexible electronics.Here,we present novel morphologically conductive hydrogel microfibers with MXene encapsulation by using a multi-injection coflow glass capillary microfluidic chip.The coaxial flows in microchannels together with fast gelation between alginate and calcium ions ensure the formation of hollow straight as well as helical microfibers and guarantee the in situ encapsulation of MXene.The resultant hollow straight and helical MXene hydrogel microfibers were with highly controllable morphologies and package features.Benefiting from the easy manipulation of the microfluidics,the structure compositions and the sizes of MXene hydrogel microfibers could be easily tailored by varying different flow rates.It was demonstrated that these morphologically conductive MXene hydrogel microfibers were with outstanding capabilities of sensitive responses to motion and photothermal stimulations,according to their corresponding resistance changes.Thus,we believe that our morphologically conductive MXene hydrogel microfibers with these excellent features will find important applications in smart flexible electronics especially electronic skins.

Responsive Janus Structural Color Hydrogel Micromotors for Label-Free Multiplex Assays

Micromotors with self-propelling ability demonstrate great values in highly sensitive analysis.Developing novel micromotors to achieve label-free multiplex assay is particularly intriguing in terms of detection efficiency.Herein,structural color micromotors(SCMs)were developed and employed for this purpose.The SCMs were derived from phase separation of droplet templates and exhibited a Janus structure with two distinct sections,including one with structural colors and the other providing catalytic selfpropelling functions.Besides,the SCMs were functionalized with ion-responsive aptamers,through which the interaction between the ions and aptamers resulted in the shift of the intrinsic color of the SCMs.It was demonstrated that the SCMs could realize multiplex label-free detection of ions based on their optical coding capacity and responsive behaviors.Moreover,the detection sensitivity was greatly improved benefiting from the autonomous motion of the SCMs which enhanced the ion-aptamer interactions.We anticipate that the SCMs can significantly promote the development of multiplex assay and biomedical fields.

仿生包裹钙钛矿量子点纤维的微流控制备

由于钙钛矿量子点诸多的优良特性,基于其的功能材料已经得到了广泛开发.本文受蜘蛛纺丝工艺启发,通过多相流微流控方式制备了具有可控形态和功能的包裹钙钛矿量子点的超细纤维.将钙钛矿量子点前驱液引入内相毛细管阵列的通道中并将它们在其中混合,而外部通道中通入聚偏二氟乙烯(PVDF)的N,N-二甲基甲酰胺溶液作为壳层纤维的反应溶液.在此过程中,随着外部PVDF纤维的形成,内部钙钛矿量子点前驱液中阴阳离子原位合成,并能够很好地包封在纤维核层中,从而免受外部环境对于结构的破坏.微流控制备纤维的过程高度可控,除了直纤维外,也能制备螺旋纤维,并且还能调节这些纤维的荧光颜色即内部包裹量子点的发射峰.此外,我们探究了这些纤维作为荧光材料在条形码中的应用,以及作为柔性光电探测器的潜在应用,证明了这类纤维在不同领域中具有广泛而灵活的应用潜能.

Synergistic integration of metal nanoclusters and biomolecules as hybrid systems for therapeutic applications

Therapeutic nanoparticles are designed to enhance efficacy,real-time monitoring,targeting accuracy,biocompatibility,biodegradability,safety,and the synergy of diagnosis and treatment of diseases by leveraging the unique physicochemical and biological properties of well-developed bio-nanomaterials.Recently,bio-inspired metal nanoclusters(NCs)consisting of several to roughly dozens of atoms(<2 nm)have attracted increasing research interest,owing to their ultrafine size,tunable fluorescent capability,good biocompatibility,variable metallic composition,and extensive surface bio-functionalization.Hybrid coreeshell nanostructures that effectively incorporate unique fluorescent inorganic moieties with various biomolecules,such as proteins(enzymes,antigens,and antibodies),DNA,and specific cells,create fluorescently visualized molecular nanoparticle.The resultant nanoparticles possess combinatorial properties and synergistic efficacy,such as simplicity,active bio-responsiveness,improved applicability,and low cost,for combination therapy,such as accurate targeting,bioimaging,and enhanced therapeutic and biocatalytic effects.In contrast to larger nanoparticles,bio-inspired metal NCs allow rapid renal clearance and better pharmacokinetics in biological systems.Notably,advances in nanoscience,interfacial chemistry,and biotechnologies have further spurred researchers to explore bio-inspired metal NCs for therapeutic purposes.The current review presents a comprehensive and timely overview of various metal NCs for various therapeutic applications,with a special emphasis on the design rationale behind the use of biomolecules/cells as the main scaffolds.In the different hybrid platform,we summarize the current challenges and emerging perspectives,which are expected to offer in-depth insight into the rational design of bio-inspired metal NCs for personalized treatment and clinical translation.

Microfluidic generation of barcodes with in situ synthesized perovskite quantum dot encapsulation

Perovskite quantum dots(PQDs)are new class of optoelectronic materials,which have been widely studied for their extraordinary physical properties.Attempts to develop these materials are tending to make their fabrication much controllable and extend their values in different areas.Here,we present a novel strategy for one-step in situ synthesis of PQD-encapsulated barcode particles with the assistance of microfluidic technique.By changing the halide ratio in perovskite precursor solutions that emulsified in microfluidic devices,a series of PQDs with different colors have been successfully fabricated,which made them ideal materials as barcodes.Because of the stable encapsulation of ethyleneglycol dimethacrylate(EGDMA)resin,the PQD-encapsulated barcode particles were with no cytotoxicity and could be anti-quenched.It was demonstrated for the first time that the PQD-encapsutated barcode particles by microfluidics were valuable for multiplex biomolecular encoding and assays.These features indicate that the PQD-encapsutated barcode particles by microfluidics are ideal for many practical applications and have a broad prospect in biomedical field.

Jellyfish Tentacle‑Inspired Hydrogel Microfibers Implanted with Discrete Structural Color Microsphere Tactile Sensing Units

Tactile sensors with distinctive ability to imitate skins have attracted considerable attention from researches for applications in a variety of sensing fields.Here,inspired by the tentacles of jellyfish,biomimetic hydrogel microfibers were fabricated to be implanted with discrete structural color microsphere units for spatial tactile sensing.By employing a microfluidic spinning technology,the generated microfibers were with high microsphere encapsulation features and controllable morphologies because of the density match of microspheres and the pre-hydrogel solution.In addition,benefitting from the easy manipulation of the microfluidics,microfibers implanted with different structural color microspheres could also be realized.It was demonstrated that the resultant microfibers would show synchronous shifts of photonic bandgaps as well as structural color when a local force like pressure or tension was applied to the microsphere part.Based on the localization of finger bending experiments,the practical values of the bioinspired microfibers have also been proved as spatial tactile sensors.Thus,it is believed that the proposed bioinspired hydrogel microfibers are greatly significant in diverse sensing application fields.

Responsive Janus Structural Color Hydrogel Micromotors for Label-Free Multiplex Assays

Micromotors with self-propelling ability demonstrate great values in highly sensitive analysis.Developing novel micromotors to achieve label-free multiplex assay is particularly intriguing in terms of detection efficiency.Herein,structural color micromotors(SCMs)were developed and employed for this purpose.The SCMs were derived from phase separation of droplet templates and exhibited a Janus structure with two distinct sections,including one with structural colors and the other providing catalytic selfpropelling functions.Besides,the SCMs were functionalized with ion-responsive aptamers,through which the interaction between the ions and aptamers resulted in the shift of the intrinsic color of the SCMs.It was demonstrated that the SCMs could realize multiplex label-free detection of ions based on their optical coding capacity and responsive behaviors.Moreover,the detection sensitivity was greatly improved benefiting from the autonomous motion of the SCMs which enhanced the ion-aptamer interactions.We anticipate that the SCMs can significantly promote the development of multiplex assay and biomedical fields.

Programmable microfluidic manipulations for biomedical applications

Fluid manipulation plays an important role in biomedical applications such as biochemical assays,medical diag-nostics,and drug development.Programmable fluidic manipulation at the microscale is highly desired in both fundamental and practical aspects.In this paper,we summarize some of the latest studies that achieve pro-grammable fluidic manipulation through intricate capillaric circuits design,construction of biomimetic metasur-face,and responsive surface wettability control.We highlight the working principle of each system and concisely discuss their design criterion,technical improvements,and implications for future study.We envision that with multidisciplinary efforts,microfluidics would continue to bring vast opportunities to biomedical fields and make contributions to human health.

Wearable microneedle-integrated sensors for household health monitoring

Wearable biosensors,which aim at providing continuous,real-time physiological information via monitoring and screening biomarkers in human body,are receiving increasing attention among various fields including dis-ease treatment,diagnosis and self-health management.The ongoing development in this realm starves for the exploration of fully-integrated,non-invasive devices.In this paper,we review the latest achievements with break-through significance on the wearable biosensors.We start with the classification of different types of wearable electronic devices and analyze their characteristics and application values.Subsequently,we introduce a fully-integrated microneedle-based sensor and provide an in-depth look at its structure,subcomponents and in vivo performances.Finally,we put forward critical commentaries and clarify the direction of future researches.