Construction of microenvironmental biointerfaces

Biomaterial acts as artificial extracellular matrix for providing a provisional three-dimensional (3D) microenvironments to interact biophysically and/or biochemically with cells to regulate cell behaviors,such as cell adhesion,migration,prolifera-

Biointerface engineering of self-protective bionic nanomissiles for targeted synergistic chemotherapy

Erythrocyte membrane(EM)-camouflaged chemotherapeutic delivery nanovehicles hold promise for solid tumor therapy because of their excellent biostability and biocompatibility. However, it is accompanied with insufficient targeting effect and deficient pharmacokinetic behavior due to the lack of a regulated biointerface to navigate and overcome biological transportation obstacles in solid tumor therapy.Herein, an anti-epidermal growth factor receptor(EGFR) aptamer(EApt) modified and EM-cloaked chemotherapeutic nanomissile delivery system was constructed. The anchored-EApt acting as a specific EGFR suppressor promotes to inhibit the overexpression of EGFR and initiate the cell apoptosis. Importantly, the resulting PLGA-DOX@EM-EApt orchestrated the bioactivity of each component and provided synergistic cell apoptosis and antitumor effects by precisely suppressing EGFR expression levels and delivering DOX. The in vitro and in vivo experimental results confirmed that the immune escape and active targeting behaviors of PLGA-DOX@EM-EApt could significantly promote its drug retention and tumor inhibition abilities. Our findings propose a novel strategy using the biointerface functionalization technique, demonstrating a promising therapeutic platform via a biomimetic drug delivery system for precise solid tumor recognition and synergistic therapy.

Engineering subcellular-patterned biointerfaces to regulate the surface wetting of multicellular spheroids

Studying the wetting behaviors of multicellular spheroids is crucial in the fields of embryo implantation, cancer propagation, and tissue repair. Existing strategies for controlling the wetting of multicellular spheroids mainly focus on surface chemistry and substrate rigidity. Although topography is another important feature in the biological micro-environment, its effect on multicellular spheroid wetting has seldom been explored. In this study, the influence of topography on the surface wetting of multicellular spheroids was investigated using subcellular- patterned opal films with controllable colloidal particle diameters （from 200 to 1,500 nm）. The wetting of hepatoma carcinoma cellular （Hep G2） spheroids was impaired on opal films compared with that on flat substrates, and the wetting rate decreased as colloidal particle diameter increased. The decrement reached 48.5% when the colloidal particle diameter was 1,500 nm. The subcellular-patterned topography in opal films drastically reduced the cellular mobility in precursor films, especially the frontier cells in the leading edge. The frontier cells failed to form mature focal adhesions and stress fibers on micro-patterned opal films. This was due to gaps between colloidal particles leaving adhesion vacancies, causing weak cell-substrate adhesion and consequent retarded migration of Hep G2 spheroids. Our study manifests the inhibiting effects of subcellular-patterned topography on the wetting behaviors of multicellular spheroids, providing new insight into tissue wetting-associated treatments and biomaterial design.

Characterization and manipulation of the photosystem Ⅱ-semiconductor interfacial molecular interactions in solar-to-chemical energy conversion

Semi-artificial photosynthesis interfacing catalytic protein machinery with synthetic photocatalysts exhibits great potential in solar-to-chemical energy conversion. However, characterizing and manipulating the molecular integration structure at the biotic-abiotic interface remain a challenging task. Herein,the biointerface molecular integration details of photosystem II(PSII)-semiconductor hybrids, including the PSII orientation, interfacial microdomains, and overall structure modulation, are systematically interrogated by lysine reactivity profiling mass spectrometry. We demonstrate the semiconductor surface biocompatibility is essential to the PSII self-assembly with uniform orientation and electroactive structure.Highly directional localization of PSII onto more hydrophilic Ru/Sr Ti O_(3):Rh surface exhibits less disturbance on PSII structure and electron transfer chain, beneficial to the high water splitting activity.Further, rational modification of hydrophobic Ru_(2)S_(3)/Cd S surface with biocompatible protamine can improve the hybrid O_(2)-evolving activity 83.3%. Our results provide the mechanistic understanding to the structure–activity relationship of PSII-semiconductor hybrids and contribute to their rational design in the future.

Proliferation-mediated asymmetric nanoencapsulation of singlecell and motility differentiation

The biointerface engineering of living cells by creating an abiotic shell has important implications for endowing cells with exogenous properties with improved cellular behavior,which then boosts the development of the emerging field of living cell hybrid materials.Herein,we develop a way to perform active nanoencapsulation of single cell,which then endows the encapsulated cells with motion ability that they do not inherently possess.The emerging motion characteristics of the encapsulated cells could be self-regulated in terms of both the motion velocity and orbits by different proliferation modes.Accordingly,by taking advantage of the emergence of differentiated moving abilities,we achieve the self-sorting between mother cells and daughter cells in a proliferated Saccharomyces cerevisiae cell community.Therefore,it is anticipated that our highlighted study could not only serve as a new technique in the field of single-cell biology analysis and sorting such as in studying the aging process in Saccharomyces cerevisiae,but also open up opportunities to manipulate cell functionality by creating biohybrid materials to fill the gap between biological systems and engineering abiotic materials.

Lubricant skin on diverse biomaterials with complex shapes via polydopamine-mediated surface functionalization for biomedical applications

Implantable biomedical devices require an anti-biofouling,mechanically robust,low friction surface for a prolonged lifespan and improved performance.However,there exist no methods that could provide uniform and effective coatings for medical devices with complex shapes and materials to prevent immune-related side effects and thrombosis when they encounter biological tissues.Here,we report a lubricant skin(L-skin),a coating method based on the application of thin layers of bio-adhesive and lubricant-swellable perfluoropolymer that impart anti-biofouling,frictionless,robust,and heat-mediated self-healing properties.We demonstrate biocompatible,mechanically robust,and sterilization-safe L-skin in applications of bioprinting,microfluidics,catheter,and long and narrow medical tubing.We envision that diverse applications of L-skin improve device longevity,as well as anti-biofouling attributes in biomedical devices with complex shapes and material compositions.

Surface roughness and its role in mediating cell adhesion on cobalt-chromium-molybdenum alloys

Co-Cr-Mo ally(CCM)is commonly used for orthopaedic and dental implants due to its excellent mechanical properties and corrosion resistance.However,the influence of surface roughness on cell attachment and proliferation remains unclear.This study aimed to elucidate the impact of surface roughness of CCM on the attachment and proliferation of osteoblasts.CCM samples with different values of surface rouges were prepared by polishing.MC3T3-E1 mouse osteoblasts were used for cell culture experiments.Cell attachment,morphology,and the expression of actin stress fibres,vinculin,and distri-bution of yes-associated protein were analysed.Our results suggest that surface rough-ness does not significantly affect cell attachment and proliferation on CCM,unlike on titanium.Thus implies that other properties of CCM,such as physicochemical properties,may play a more substantial role in modulating cell behaviour.This study provides important insights into the design of CCM implants,suggesting that approaches beyond tuning surface roughness may be necessary to improve biocompatibility and osseointegration.

Preparation,properties and biomedical applications progress of 1D magnetic nanomaterials with iron

1D magnetic nanomaterials with iron,with the special physical properties and biological behaviour,have been found to possess the great promising applications in many fields.In this review,the components,structure,physicochemical properties,biocompatibility and in vitro and in vivo biomedical functions of magnetic nanowires(MNWs),nanorods(MNRs)with iron are summarised,especially their anisotropy shape and magnetism result in their many applications in biodetections and medical treatment fields.The potential future functions of these 1D magnetic nanomaterials compared to magnetic nanoparticles also is discussed by highlighting the possibility of integration with other metal-compositions or bio-compositions and with existing biotechnology as well as by point-ing out their specific properties.Current limitations in the property improvement and issues related with the outcome of the MNRs in the body are also summarised in order to address the remaining challenge for the extended biomedical functions of MNRs in the clinical application field.

Controllable deformation based self-adaptive drag reduction for complex surface

Reduction of energy consumption and improvement of cruising speed are greatly necessary for underwater vehicles.Previously,regular riblets have been machined and the drag reduction has been verified;however,the riblet parameters are not adjusted like the denticles of sharkskin,which adapt quickly to the complex changing fluid flow.To achieve an improved drag reduction effect on the complicated shape surface,a simple,low-cost,and timesaving stretching approach was proposed to adjust the riblet parameters on the underwater vehicle surface by controllable deformation.Nature latex rubber membrane with regular micro-riblets was prepared as a stretching flexible film,and the spacing and height of the micro-riblets were adjusted by adaptive control of the stretching ratio.The circulating water channel experiment verified the effectiveness and feasibility of the selfadaptive drag reduction by the controllable deformation method.The results demonstrated that the drag reduction rate of the controllable deformation bionic fish skin was 4.26%compared with a smooth surface at 0.25 m/s with an angle of attack of 0°,which is better than any other angle.The controllable deformation bionic fish skin provides a feasible method for the drag reduction of complex surface adaptive underwater vehicles.

A study on the biocompatibility of ramie fibre for medical dressing application

In order to explore the potential application of Ramie fibre(RF)in medical dressing,the absorbency ratio of ramie fibre cloth,medical gauze and natural cotton fibre cloth was tested,and the factors affecting the absorbency ratio of materials were analysed.Meanwhile,the hemocompatibility of the three fibre materials were also studied.The results showed that the RF cloth had good moisture absorption and hemocompatibility.Therefore,RF is a potential material for medical dressing.

Cross-fibrillation of insulin and amyloid β on chiral surfaces： Chirality affects aggregation kinetics and cytotoxicity

Recent clinical and epidemiological research has shown that insulin is associated with the pathological mechanisms of Alzheimer＇s disease （AD） and can protect against the oxidative stress triggered by amyloidq3 peptide （Aβ3）. Herein, we present a systematic study on how the cross-fibrillation of insulin and Aβ is influenced by the surface chirality of an interface designed to mimic their aggregation on the cytomembrane. Intriguingly, the surface chirality strongly affected the aggregation kinetics, structure, morphologβ and cellular responses of the cross-aggregates of insulin and Aβ. On a D-phenylalanine- modified surface, Aβ induced insulin to co-aggregate into β-sheet-rich fibrils and cross-fibrils that showed a pronounced cellular toxicity. However, on an L-phenylalanine-modified surface, insulin and Aβ3 formed non-toxic amorphous aggregates. Our work indicates that surface chirality can influence the cross- fibrillation of Aβ and insulin as well as the cytotoxicity of their aggregates.

3D electronic and photonic structures as active biological interfaces

Biocompatible materials and structures with three-dimensional(3D)architectures establish an ideal platform for the integration of living cells and tissues,serving as desirable interfaces between biotic and abiotic systems.While conventional 3D bioscaffolds provide a mechanical support for biomatters,emerging developments of micro-,nano-,and mesoscale electronic and photonic devices offer new paradigms in analyzing and interrogating biosystems.In this review,we summarize recent advances in the development of 3D functional biointerfaces,with a particular focus on electrically and optically active materials,devices,and structures.We first give an overview of representative methods for manufacturing 3D biointegrated structures,such as chemical synthesis,microfabrication,mechanical assembly,and 3D printing.Subsequently,exemplary 3D nano-,micro-,and mesostructures based on various materials,including semiconductors,metals,and polymers are presented.Finally,we highlight the latest progress on versatile applications of such active 3D structures in the biomedical field,like cell culturing,biosignal sensing/modulation,and tissue regeneration.We believe future 3D micro-,nano-,and mesostructures that incorporate electrical and/or optical functionalities will not only profoundly advance the fundamental studies in biological sciences,but also create enormous opportunities for medical diagnostics and therapies.

Friction behaviour between a laparoscopic grasper and the large intestine during minimally invasive surgery

Slippage is a common phenomenon between laparoscopic graspers and tissues during minimally invasive surgery,which may lead to inefficient surgical operations,prolonged operation time,and increased patient suffering.The stability factors related to the friction behaviour between laparoscopic graspers and the large intestine,including bio-surface liquids,pulling angle,and surface profile of graspers,were studied.The friction behav-iour at the large intestine-grasper interface was tested using a UMT-II tribometer under the conditions of clamping force of 1-4 N,sliding displacement of 15 mm,and sliding velocity of 2 mm/s to simulate the grasping and pulling operations of soft tissue.The results showed that the bio-surface liquid(serum)of the large intestine significantly decreased the friction coefficient,thus reducing the grasping efficiency.A pulling angle of 15°could generate the peak frictional force and enhance the grasping stability.The frictional force increased with the ratio of the profile surface area of the grasper.These results demonstrate that the grasping stability can be improved by changing either the bio-surface liquid condition or the pulling angle.In addition,a grasper with a larger profile surface area can also prevent slippage due to its significant influence on the pressure distribution and actual contact area for tissue retention.

Dynamic photonic barcodes for molecular detection based on cavity-enhanced energy transfer

Optical barcodes have demonstrated a great potential in multiplexed bioassays and cell tracking for their distinctive spectral fingerprints.The vast majority of optical barcodes were designed to identify a specific target by fluorescence emission spectra,without being able to characterize dynamic changes in response to analytes through time.To overcome these limitations,the concept of the bioresponsive dynamic photonic barcode was proposed by exploiting interfacial energy transfer between a microdroplet cavity and binding molecules.Whispering-gallery modes resulting from cavity-enhanced energy transfer were therefore converted into photonic barcodes to identify binding activities,in which more than trillions of distinctive barcodes could be generated by a single droplet.Dynamic spectral barcoding was achieved by a significant improvement in terms of signal-to-noise ratio upon binding to target molecules.Theoretical studies and experiments were conducted to elucidate the effect of different cavity sizes and analyte concentrations.Timeresolved fluorescence lifetime was implemented to investigate the role of radiative and non-radiative energy transfer.Finally,microdroplet photonic barcodes were employed in biodetection to exhibit great potential in fulfilling biomedical applications.

Chemical Approaches to Emerging Advancements in Deformable Bioelectronics:Synthesis,Device Concepts,Performance,and Applications

This mini review examines the current advances and future prospects of chemical approaches in deformable bioelectronics,emphasizing their transformative potential in healthcare and other sectors.The mini review outlines novel fabrication strategies that rely on chemical principles to create adaptable,comfortable,and durable bioelectronic devices that are capable of seamlessly integrating into the dynamic biological environment.The discussion also extends to the integration of innovative device concepts that enhance the outcomes in both sensing and modulation functionalities.Performance-enhancing strategies that use chemistry to refine the sensitivity and precision of these devices are also highlighted.Moreover,the mini review explores the emerging applications of chemically enhanced bioelectronic devices in healthcare,reflecting the potential of this field to revolutionize patient care and improve health monitoring.In the outlook section,this mini review investigates the promising future of transient and living bioelectronics,emphasizing the pivotal role of chemical approaches in their development.It additionally covers the potential of chemical techniques in powering bioelectronic devices using biological systems and discusses the prospective applications of chemically synthesized bioelectronic devices outside of healthcare.While the field has made substantial progress,this mini review also identifies challenges that must be addressed,thus underlining the necessity for continued research and chemical innovation in bioelectronics.