Biomimetic Membranes Research Articles

Biomimetic solar evaporator for continuous clean water production with synergistic organic dye wastewater remediation

Solar-driven water evaporation is recognized as an environment-friendly technology for sustainable clean water generation, serving the needs of both desalination and wastewater purification. However, its practical application is constrained by challenges such as single functionality and significant salt accumulation. Inspired by the transpiration of vascular plant, this work introduces a scalable and cost-effective biomimetic evaporator (PyCOF/Tri-Layers), consisting of a biomimetic hierarchical fibrous membrane (Tri-Layers) and a composite photothermal layer (PyCOF). Furthermore, the PyCOF composite, featuring an aloe-like flower structure, enhances the light trapping (95.1 %) through multiple scattering, realizing simultaneous desalination and azo dye degradation. Based on the PyCOF/Tri-Layers evaporator, we demonstrate a suspended multi-section hanging evaporation structure sustaining a consistent evaporation rate of approximately 1.41 kg m−2 h−1 over 15 days without salt accumulation, achieving above 99.3 % removal of dye pollutants within 120 min under one sun irradiation. Moreover, in outdoor experiments, the improved evaporator realizes a daily clean water yield rate of 8.73 kg m−2 d−1, and the collected water is suitable for supporting crop cultivation within an integrated solar desalination-cultivation system. This work not only provides a one-stone-two-birds approach for generating clean water from polluted seawater, but also presents promising possibilities for offshore self-sustainable agriculture production.

Studies of Protein Binding to Biomimetic Membranes Using a Group of Uniform Materials Based on Organic Salts Derived From 8-Anilino-1-naphthalenesulfonic Acid.

Tuning the 8-anilino-1-naphthalenesulfonic acid (ANS) structure usually requires harsh conditions and long reaction times, which can result in low yields. Herein, ANS was modified to form an ANS group of uniform materials based on organic salts (GUMBOS), prepared with simple metathesis reactions and distinct cations, namely tetrabutylammonium (N4444), tetrahexylammonium (N6666), and tetrabutylphosphonium (P4444). These ANS-based GUMBOS were investigated as fluorescent probes for membrane binding studies with four proteins having distinct physicochemical properties. Liposomes of 1,2-dimyristoyl-sn-glycero-3-phosphocholine were employed as membrane models as a result of their ability to mimic the structure and chemical composition of cell membranes. Changes in fluorescence intensity were used to monitor protein binding to liposomes, and adsorption data were fitted to a Freundlich-like isotherm. It was determined that [N4444][ANS] and [P4444][ANS] GUMBOS have enhanced optical properties and lipophilicity as compared to parent ANS. As a result, these two GUMBOS were selected for subsequent protein-membrane binding studies. Both [N4444][ANS] and [P4444][ANS] GUMBOS and parent ANS independently reached membrane saturation within the same concentration range. Furthermore, distinct fluorescence responses were observed upon the addition of proteins to each probe, which demonstrates the impact of properties such as lipophilicity on the binding process. The relative maintenance of binding cooperativity and maximum fluorescence intensity suggests that proteins compete with ANS-based probes for the same membrane binding sites. Finally, this GUMBOS-based approach is simple, rapid, and involves relatively small amounts of reagents, making it attractive for high-throughput purposes. These results presented herein can also provide relevant information for designing GUMBOS with ameliorated properties.

Cholesterol drives enantiospecific effects of ibuprofen in biomimetic membranes

The interaction between chiral drugs and biomimetic membranes is of interest in biophysical research and biotechnological applications. There is a belief that the membrane composition, particularly the presence of cholesterol, could play a pivotal role in determining enantiospecific effects of pharmaceuticals. Our study explores this topic focusing on the interaction of ibuprofen enantiomers (S- and R-IBP) with cholesterol-containing model membranes. The effects of S- and R-IBP at 20 mol% on bilayer mixtures of dipalmitoylphosphatidylcholine (DPPC) with 0, 10, 20 and 50 mol% cholesterol were investigated using circular dichroism and spin-label electron spin resonance. Morphological changes due to IBP enantiomers were studied with atomic force microscopy on supported cholesterol-containing DPPC monolayers. The results reveal that IBP isoforms significantly and equally interact with pure DPPC lipid assemblies. Cholesterol content, besides modifying the structure and the morphology of the membranes, triggers the drug enantioselectivity at 10 and 20 mol%, with the enantiomers differently adsorbing on membranes and perturbing them. The spectroscopic and the microscopic data indicate that IBP stereospecificity is markedly reduced at equimolar content of Chol mixed with DPPC. This study provides new insights into the role of cholesterol in modulating enantiospecific effects of IBP in lipid membranes.

Halophiles and their adaptations: A comprehensive review on recent progress and prospects in biodesalination applications

AbstractWorldwide climate change, rising population, and industrialization have raised the global demand for freshwater. Desalinating brackish water has become a sustainable technology for drinking and agriculture to overcome global water scarcity. Thriving biodesalination technology has become more attractive and eco‐friendly than the present physicochemical desalination methods, which are expensive and energy‐intensive. Researchers are exploring the bioutilization of nature's potential for desalination using halophiles like haloarchaea, halobacteria, halophytic algae, and plants. Biomimetic desalination membranes have been developed, inspired by the desalination mechanism in animals. This comprehensive review explores recent advancements and potential applications of halophiles in biodesalination to exploit them effectively. It provides an overview of the opportunities and challenges associated with harnessing halophiles for the removal of salts from brackish and seawater sources. This review also focuses on insights into biomolecules produced by the halophilic microorganisms and halophytes in the desalination process. Understanding the mechanism of action of these biomolecules will edify the effective unexplored research areas in biomimicry and bioutilization to overcome the existing limitations in water treatment.

The Effects of the Coating and Aging of Biodegradable Polylactic Acid Membranes on In Vitro Primary Human Retinal Pigment Epithelium Cells.

Age-related macular degeneration (AMD) is the most frequent cause of blindness in developed countries. The replacement of dysfunctional human retinal pigment epithelium (hRPE) cells by the transplantation of in vitro-cultivated hRPE cells to the affected area emerges as a feasible strategy for regenerative therapy. Synthetic biomimetic membranes arise as powerful hRPE cell carriers, but as biodegradability is a requirement, it also poses a challenge due to its limited durability. hRPE cells exhibit several characteristics that putatively respond to the type of membrane carrier, and they can be used as biomarkers to evaluate and further optimize such membranes. Here, we analyze the pigmentation, transepithelial resistance, genome integrity, and maturation markers of hRPE cells plated on commercial polycarbonate (PC) versus in-house electrospun polylactide-based (PLA) membranes, both enabling separate apical/basolateral compartments. Our results show that PLA is superior to PC-based membranes for the cultivation of hRPEs, and the BEST1/RPE65 maturation markers emerge as the best biomarkers for addressing the quality of hRPE cultivated in vitro. The stability of the cultures was observed to be affected by PLA aging, which is an effect that could be partially palliated by the coating of the PLA membranes.

Analysis of the Prognostic Factors That Influence the Outcome of Periapical Surgery, including Biomimetic Membranes for Tissue Regeneration: A Review.

The objective of this study was to analyze the prognostic factors that influence the outcome of periapical surgery. A systematic search of the literature was carried out using PubMed and Scopus databases between January 2000 and December 2023 with no language limitations. The PICO question of the present systematic review was: What prognostic factors may influence the outcome of periapical surgery? The most relevant randomized controlled clinical trials (RCTs), prospective clinical trials, retrospective studies, and meta-analyses (n = 44) were selected from 134 articles. The reviewed literature evidenced that bone-lesion healing could significantly be improved by the absence of deep periodontal pockets (>4 mm), localization in anterior teeth, the absence of pain and/or preoperative symptoms, a size of bone lesion < 5 mm, the use of ultrasound, the correct placement of retrograde filling material, and the use of different biomimetic membranes for guided tissue regeneration (GTR). Some preoperative and intraoperative factors could significantly improve the prognosis of periapical surgery. However, these results were not conclusive, and further high-quality research is required.

Self-Stimulated Photodynamic Nanoreactor in Combination with CXCR4 Antagonists for Antileukemia Therapy.

The treatment of acute myeloid leukemia (AML) remains unsatisfactory, owing to the absence of efficacious therapy regimens over decades. However, advances in molecular biology, including inhibiting the CXCR4/CXCL12 biological axis, have introduced novel therapeutic options for AML. Additionally, self-stimulated phototherapy can solve the poor light penetration from external sources, and it will overcome the limitation that traditional phototherapy cannot be applied to the treatment of AML. Herein, we designed and manufactured a self-stimulated photodynamic nanoreactor to enhance antileukemia efficacy and suppress leukemia recurrence and metastasis in AML mouse models. To fulfill our design, we utilized the CXCR4/CXCL12 biological axis and biomimetic cell membranes in conjunction with self-stimulated phototherapy. This nanoreactor possesses the capability to migrate into the bone marrow cavity, inhibit AML cells from infiltrating into the visceral organ, significantly enhance the antileukemia effect, and prolong the survival time of leukemic mice. Therefore, this nanoreactor has significant potential for achieving high success rates and low recurrence rates in leukemia treatment.

Microliquid/Liquid Interfacial Sensors: Biomimetic Investigation of Transmembrane Mechanisms and Real-Time Determinations of Clemastine, Cyproheptadine, Epinastine, Cetirizine, and Desloratadine.

Antihistamines relieve allergic symptoms by inhibiting the action of histamine. Further understanding of antihistamine transmembrane mechanisms and optimizing the selectivity and real-time monitoring capabilities of drug sensors is necessary. In this study, a micrometer liquid/liquid (L/L) interfacial sensor has served as a biomimetic membrane to investigate the mechanism of interfacial transfer of five antihistamines, i.e., clemastine (CLE), cyproheptadine (CYP), epinastine (EPI), desloratadine (DSL), and cetirizine (CET), and realize the real-time determinations. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques have been used to uncover the electrochemical transfer behavior of the five antihistamines at the L/L interface. Additionally, finite element simulations (FEMs) have been employed to reveal the thermodynamics and kinetics of the process. Visualization of antihistamine partitioning in two phases at different pH values can be realized by ion partition diagrams (IPDs). The IPDs also reveal the transfer mechanism at the L/L interface and provide effective lipophilicity at different pH values. Real-time determinations of these antihistamines have been achieved through potentiostatic chronoamperometry (I-t), exhibiting good selectivity with the addition of nine common organic or inorganic compounds in living organisms and revealing the potential for in vivo pharmacokinetics. Besides providing a satisfactory surrogate for studying the transmembrane mechanism of antihistamines, this work also sheds light on micro- and nano L/L interfacial sensors for in vivo analysis of pharmacokinetics at a single-cell or single-organelle level.

Biomimetic Vesicles with Designer Phospholipids Can Sense Environmental Redox Cues.

Cell-like materials that sense environmental cues can serve as next-generation biosensors and help advance the understanding of intercellular communication. Currently, bottom-up engineering of protocell models from molecular building blocks remains a grand challenge chemists face. Herein, we describe giant unilamellar vesicles (GUVs) with biomimetic lipid membranes capable of sensing environmental redox cues. The GUVs employ activity-based sensing through designer phospholipids that are fluorescently activated in response to specific reductive (hydrogen sulfide) or oxidative (hydrogen peroxide) conditions. These synthetic phospholipids are derived from 1,2-dipalmitoyl-rac-glycero-3-phosphocholine and they possess a headgroup with heterocyclic aromatic motifs. Despite their structural deviation from the phosphocholine headgroup, the designer phospholipids (0.5-1.0 mol %) mixed with natural lipids can vesiculate, and the resulting GUVs (7-20 μm in diameter) remain intact over the course of redox sensing. All-atom molecular dynamics simulations gave insight into how these lipids are positioned within the hydrophobic core of the membrane bilayer and at the membrane-water interface. This work provides a purely chemical method to investigate potential redox signaling and opens up new design opportunities for soft materials that mimic protocells.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

Dehydrated Biomimetic Membranes with Skinlike Structure and Function.

Novel vapor-permeable materials are sought after for applications in protective wear, energy generation, and water treatment. Current impermeable protective materials effectively block harmful agents but trap heat due to poor water vapor transfer. Here we present a new class of materials, vapor permeable dehydrated nanoporous biomimetic membranes (DBMs), based on channel proteins. This application for biomimetic membranes is unexpected as channel proteins and biomimetic membranes were assumed to be unstable under dry conditions. DBMs mimic human skin's structure to offer both high vapor transport and small molecule exclusion under dry conditions. DBMs feature highly organized pores resembling sweat pores in human skin, but at super high densities (>1012 pores/cm2). These DBMs achieved exceptional water vapor transport rates, surpassing commercial breathable fabrics by up to 6.2 times, despite containing >2 orders of magnitude smaller pores (1 nm vs >700 nm). These DBMs effectively excluded model biological agents and harmful chemicals both in liquid and vapor phases, again in contrast with the commercial breathable fabrics. Remarkably, while hydrated biomimetic membranes were highly permeable to liquid water, they exhibited higher water resistances after dehydration at values >38 times that of commercial breathable fabrics. Molecular dynamics simulations support our hypothesis that dehydration induced protein hydrophobicity increases which enhanced DBM performance. DBMs hold promise for various applications, including membrane distillation, dehumidification, and protective barriers for atmospheric water harvesting materials.

Docosahexaenoic Acid Controls Pulmonary Macrophage Lipid Raft Size and Inflammation

BackgroundDocosahexaenoic acid (DHA) controls the biophysical organization of plasma membrane sphingolipid/cholesterol-enriched lipid rafts to exert anti-inflammatory effects, particularly in lymphocytes. However, the impact of DHA on the spatial arrangement of alveolar macrophage lipid rafts and inflammation is unknown. ObjectivesThe primary objective was to determine how DHA controls lipid raft organization and function of alveolar macrophages. As proof-of-concept, we also investigated DHA’s anti-inflammatory effects on select pulmonary inflammatory markers with a murine influenza model. MethodsMH-S cells, an alveolar macrophage line, were treated with 50 μM DHA or vehicle control and were used to study plasma membrane molecular organization with fluorescence-based methods. Biomimetic membranes and coarse grain molecular dynamic (MD) simulations were employed to investigate how DHA mechanistically controls lipid raft size. qRT-PCR, mass spectrometry, and ELISAs were used to quantify downstream inflammatory signaling transcripts, oxylipins, and cytokines, respectively. Lungs from DHA-fed influenza-infected mice were analyzed for specific inflammatory markers. ResultsDHA increased the size of lipid rafts while decreasing the molecular packing of the MH-S plasma membrane. Adding a DHA-containing phospholipid to a biomimetic lipid raft-containing membrane led to condensing, which was reversed with the removal of cholesterol. MD simulations revealed DHA nucleated lipid rafts by driving cholesterol and sphingomyelin into rafts. Downstream of the plasma membrane, DHA lowered the concentration of select inflammatory transcripts, oxylipins, and IL-6 secretion. DHA lowered pulmonary Il6 and Tnf-α mRNA expression and increased anti-inflammatory oxylipins of influenza-infected mice. ConclusionsThe data suggest a model in which the localization of DHA acyl chains to nonrafts is driving sphingomyelin and cholesterol molecules into larger lipid rafts, which may serve as a trigger to impede signaling and lower inflammation. These findings also identify alveolar macrophages as a target of DHA and underscore the anti-inflammatory properties of DHA for lung inflammation.

A Label‐Free Multitechnique Approach to Characterize the Interaction of Bioactive Compounds with Biomimetic Interfaces

Extensive research has been conducted on biomimetic interfaces mimicking the complex and diverse microenvironment of cell membranes to gain insights into bioactive compound interactions and membrane biophysics modulation. The present study proposes an innovative approach that combines five prospective label‐free methodologies (derivative spectroscopy, synchrotron small‐ and wide‐angle X‐Ray scattering, attenuated total reflection–Fourier‐transform infrared spectroscopy, quartz‐crystal microbalance with dissipation, and surface plasmon resonance) to showcase their synergistic capabilities and complementarity in investigating drug–membrane interactions. This multitechnique approach combines the real‐time monitoring of the adsorption process under continuous flow conditions with the steady‐state perspective of this process. As a proof of concept, the interaction of three bioactive compounds (caffeine, testosterone, and diclofenac) with two biomimetic membrane interfaces (multistacked lipid bilayers and supported lipid bilayers) mimicking the more ordered lipid transient phases, with and without cholesterol (lo and so), that are responsible for a variety of membrane‐associated biological activities, is investigated. The biophysical effects of the bioactives are discussed using complementary data from real‐time and steady‐state experiments, including membrane adsorption and distribution, predicted location, and induced changes in order and fluidity, encompassing bilayer thickness, hydration, and area per lipid molecule.

Biomimetic and Durably Superhydrophobic Nanofibrous Membranes for High‐Performance Waterproof and Breathable Textiles

AbstractMan‐made superhydrophobic membranes are of interest for various applications in energy, environment, and medical fields. However, simultaneously achieving durable superhydrophobicity, robust waterproofness, and high breathability of the membranes is still challenging. Herein, an efficient and powerful strategy is reported to create superhydrophobic membranes with perdurable liquid repellency and robust breathability via combining humidity‐induced electrospinning with coat‐crosslinking technology. The micro/nano rough structure is in situ constructed based on manipulating the phase separation of electrospun jets; meanwhile, the waterborne acrylic resins are bridged to the surface of nanofiber to endow the membranes with stable low surface energy via coating and crosslinking treatment. Eventually, the resultant membranes present superhydrophobicity with a water contact angle of ≈154°, good self‐cleaning and anti‐icing properties, robust waterproofness of 83.4 kPa, and high breathability of 3.71 kg m−2 d−1. More interestingly, the nanomaterials can maintain durable superhydrophobicity even after exposure to various severe conditions. The successful creation of high‐performance superhydrophobic membranes opens a new avenue for synthesizing advanced functional materials for application in a variety of fields.

Interaction of KLAKLAK-NH2 and Analogs with Biomimetic Membrane Models.

Specifically designed peptide mimetics offer higher selectivity regarding their toxicity to mammalian cells. In addition to the α-helix conformation, the specific activity is related to the peptide's ability to penetrate the cell membrane. The alterations in lipid membrane properties were addressed in the presence of the peptide KLAKLAK-NH2 and analogs containing β-alanine, strengthening the antibacterial activity and/or naphtalimide with proven anticancer properties. The molecular interactions of the peptide mimetics with POPC bilayers were studied using FTIR-ATR spectroscopy. The thermal shape fluctuation analysis of quasispherical unilamellar vesicles was applied to probe the membrane bending elasticity. The impedance characteristics of bilayer lipid membranes were measured using fast Fourier-transform electrochemical impedance spectroscopy. A lateral peptide association with the membrane is reported for β-alanine-containing peptides. The most pronounced membrane softening is found for the NphtG-KLβAKLβAK-NH2 analog containing both active groups that corroborate with the indications for 1,8-naphthalimide penetration in the lipid hydrophobic area obtained from the FTIR-ATR spectra analysis. The β-alanine substitution induces strong membrane-rigidifying properties even at very low concentrations of both β-alanine-containing peptides. The reported results are expected to advance the progress in tailoring the pharmacokinetic properties of antimicrobial peptides with strengthened stability towards enzymatic degradation. The investigation of the nonspecific interactions of peptides with model lipid membranes is featured as a useful tool to assess the antitumor and antimicrobial potential of new peptide mimetics.

Protein Coronas Derived from Mucus Act as Both Spear and Shield to Regulate Transferrin Functionalized Nanoparticle Transcellular Transport in Enterocytes.

The epithelial mucosa is a key biological barrier faced by gastrointestinal, intraoral, intranasal, ocular, and vaginal drug delivery. Ligand-modified nanoparticles demonstrate excellent ability on this process, but their efficacy is diminished by the formation of protein coronas (PCs) when they interact with biological matrices. PCs are broadly implicated in affecting the fate of NPs in vivo and in vitro, yet few studies have investigated PCs formed during interactions of NPs with the epithelial mucosa, especially mucus. In this study, we constructed transferrin modified NPs (Tf-NPs) as a model and explored the mechanisms and effects that epithelial mucosa had on PCs formation and the subsequent impact on the transcellular transport of Tf-NPs. In mucus-secreting cells, Tf-NPs adsorbed more proteins from the mucus layers, which masked, displaced, and dampened the active targeting effects of Tf-NPs, thereby weakening endocytosis and transcellular transport efficiencies. In mucus-free cells, Tf-NPs adsorbed more proteins during intracellular trafficking, which enhanced transcytosis related functions. Inspired by soft coronas and artificial biomimetic membranes, we used mucin as an "active PC" to precoat Tf-NPs (M@Tf-NPs), which limited the negative impacts of "passive PCs" formed during interface with the epithelial mucosa and improved favorable routes of endocytosis. M@Tf-NPs adsorbed more proteins associated with endoplasmic reticulum-Golgi functions, prompting enhanced intracellular transport and exocytosis. In summary, mucus shielded against the absorption of Tf-NPs, but also could be employed as a spear to break through the epithelial mucosa barrier. These findings offer a theoretical foundation and design platform to enhance the efficiency of oral-administered nanomedicines.

Preparation and optimization of an eggshell membrane-based biomaterial for GTR applications

ObjectivesGuided Tissue Regeneration (GTR) is a popular clinical procedure for periodontal tissue regeneration. However, its key component, the barrier membrane, is largely collagen-based and is still quite expensive, posing a financial burden to the patients as well as healthcare systems and negatively impacting the patient’s decision-making. Thus, our aim is to prepare a novel biomimetic GTR membrane utilizing a natural biomaterial, soluble eggshell membrane protein (SEP), which is economical as it comes from an abundant industrial waste from food and poultry industries, unlike collagen. Additive polymer, poly (lactic-co-glycolic acid) (PLGA), and a bioceramic, nano-hydroxyapatite (HAp), were added to improve its mechanical and biological properties. MethodsFor this barrier membrane preparation, we initially screened the significant factors affecting its mechanical properties using Taguchi orthogonal array design and further optimized the significant factors using response surface methodology. Furthermore, this membrane was characterized using SEM, EDAX, and ATR-FTIR, and tested for proliferation activity of human periodontal ligament fibroblasts (HPLFs). ResultsOptimization using response surface methodology predicted that the maximal tensile strength of 3.1 MPa and modulus of 39.9 MPa could be obtained at membrane composition of 8.9 wt% PLGA, 7.2 wt% of SEP, and 2 wt% HAp. Optimized PLGA/SEP/HAp membrane specimens that were electrospun on a static collector showed higher proliferation activity of HPLFs compared to tissue culture polystyrene and a commercial collagen membrane. SignificanceFrom the results observed, we can conclude that SEP-based nanofibrous GTR membrane could be a promising, environment-friendly, and cost-effective alternative for commercial collagen-based GTR membrane products.

Janus Nanofiber Membranes with Photothermal‐Enhanced Biofluid Drainage and Sterilization for Diabetic Wounds

AbstractDiabetic wounds are difficult to heal, and the key to wound healing is exudate management and effective disinfection. Inspired by the asymmetric wettability of Janus‐structured lotus leaves, herein the study has presented the design of a biomimetic asymmetric Janus membrane that integrates unidirectional biofluid drainage and photothermal‐enhanced evaporation/sterilization capabilities for accelerating diabetic wound healing. This Janus membrane is prepared by electrospinning polyacrylonitrile (PAN) nanofiber membrane containing polydopamine (PDA) on the surface of polypropylene (PP) nonwoven membrane. Such PP/PANx%PDA Janus membrane enables antigravity “pumping” of the water from the hydrophobic PP layer to the hydrophilic PANx%PDA layer within 22 s through contact points on the Janus interface. The incorporation of 30 wt% PDA in PAN imparts high photoabsorption and photothermal responsiveness, facilitating continuous volatilization of the exudate, achieving twice the displacement of water, and causing irreversible damage to bacteria. As a result, it effectively alleviates inflammation and cellular fibrosis while promoting collagen deposition due to its structure and antibacterial properties. Impressively, such photothermal‐enhanced Janus membrane achieves an impressive closure rate of 96.7% for diabetic wounds, better than that of (59.8%) for conventional bandages. Therefore, this asymmetric Janus membrane offers a promising alternative for the healing of chronic diabetic wounds.

Highly permeable and shelf-stable aquaporin biomimetic membrane based on an anodic aluminum oxide substrate

Aquaporin (AQP) biomimetic membranes are a coming-of-age technology for water purification. Although several studies have reported aquaporin biomimetic membrane fabrication to date, these membranes show low water flux mainly due to the low porosity and inherently dense structure of the polymeric substrate materials. Herein, we report a ceramic-based aquaporin biomimetic membrane based on anodic aluminum oxide (AAO) as a substrate, which has a uniform porous structure with a high aspect ratio and pore density compared to conventional polymer substrates and exhibits a high water flux of 27.6 ± 3.6 LMH (L m−2 h−1) and superior membrane selectivity of 0.11 g L−1. Briefly, the AAO substrate was functionalized with amino-silane followed by polydopamine coating, then the AQP vesicles were immobilized on the functionalized AAO substrate surface using an electrokinetic method, and the water rejection performance of the membrane was analyzed in a forward osmosis system. Furthermore, a simple cryodesiccation method is introduced to improve the storage stability and easy transportation of aquaporin membranes, which does not require special environmental conditions to transport or store them.

Bioinspired cell membrane-based nanofiltration membranes with hierarchical pore channels for fast molecular separation

Owing to intrinsic perm-selectivity, cell membranes have attracted considerable attention in the field of biomimetic membranes. Herein, largest possible cell membranes of E.coli were prepared and then used as two-dimensional (2D) materials to fabricate high-performance nanofiltration (NF) membranes. The structure parameters of the selective layer of the E.coli-NF membrane could be finely tailored through the loading mass of cell membranes and the applied pressure during vacuum filtration. The E.coli-NF membrane exhibited a high rejection towards dyes (98.5%, brilliant blue R), antibiotics (91.1%, erythromycin), and divalent ions (64.8%, sodium sulfate). The membrane effective pore size was found to be significantly smaller than the interlayer spacing because of the small intrinsic nanochannels inside the E.coli cell membranes, which is distinct from GO and MXene-based 2D membranes. Moreover, the membrane water permeance was 52.6 L m−2 h−1 bar−1, higher than that of most of the reported 2D materials-based NF membranes. The E.coli-NF membrane exhibited the typical separation behavior of the negatively charged NF membranes governed by Donnan effect and size exclusion. This work gives some insights into the fabrication of the selective membranes using cell membranes as 2D materials with intrinsic nanochannels and fruitful choices in nature.