Population-based heteropolymer design to mimic protein mixtures.

Biological fluids, the most complex blends, have compositions that constantly vary and cannot be molecularly defined1. Despite these uncertainties, proteins fluctuate, fold, function and evolve as programmed2-4. We propose that in addition to the known monomeric sequence requirements, protein sequences encode multi-pair interactions at the segmental level to navigate random encounters5,6; synthetic heteropolymers capable of emulating such interactions can replicate how proteins behave in biological fluids individually and collectively. Here, we extracted the chemical characteristics and sequential arrangement along a protein chain at the segmental level from natural protein libraries and used the information to design heteropolymer ensembles as mixtures of disordered, partially folded and folded proteins. For each heteropolymer ensemble, the level of segmental similarity to that of natural proteins determines its ability to replicate many functions of biological fluids including assisting protein folding during translation, preserving the viability of fetal bovine serum without refrigeration, enhancing the thermal stability of proteins and behaving like synthetic cytosol under biologically relevant conditions. Molecular studies further translated protein sequence information at the segmental level into intermolecular interactions with a defined range, degree of diversity and temporal and spatial availability. This framework provides valuable guiding principles to synthetically realize protein properties, engineer bio/abiotic hybrid materials and, ultimately, realize matter-to-life transformations.

A somato-cognitive action network alternates with effector regions in motor cortex.

Motor cortex (M1) has been thought to form a continuous somatotopic homunculus extending down the precentral gyrus from foot to face representations1,2, despite evidence for concentric functional zones3 and maps of complex actions4. Here, using precision functional magnetic resonance imaging (fMRI) methods, we find that the classic homunculus is interrupted by regions with distinct connectivity, structure and function, alternating with effector-specific (foot, hand and mouth) areas. These inter-effector regions exhibit decreased cortical thickness and strong functional connectivity to each other, as well as to the cingulo-opercular network (CON), critical for action5 and physiological control6, arousal7, errors8 and pain9. This interdigitation of action control-linked and motor effector regions was verified in the three largest fMRI datasets. Macaque and pediatric (newborn, infant and child) precision fMRI suggested cross-species homologues and developmental precursors of the inter-effector system. A battery of motor and action fMRI tasks documented concentric effector somatotopies, separated by the CON-linked inter-effector regions. The inter-effectors lacked movement specificity and co-activated during action planning (coordination of hands and feet) and axial body movement (such as of the abdomen or eyebrows). These results, together with previous studies demonstrating stimulation-evoked complex actions4 and connectivity to internal organs10 such as the adrenal medulla, suggest that M1 is punctuated by a system for whole-body action planning, the somato-cognitive action network (SCAN). In M1, two parallel systems intertwine, forming an integrate-isolate pattern: effector-specific regions (foot, hand and mouth) for isolating fine motor control and the SCAN for integrating goals, physiology and body movement.

Near-complete depolymerization of polyesters with nano-dispersed enzymes.

Successfully interfacing enzymes and biomachinery with polymers affords on-demand modification and/or programmable degradation during the manufacture, utilization and disposal of plastics, but requires controlled biocatalysis in solid matrices with macromolecular substrates1-7. Embedding enzyme microparticles speeds up polyester degradation, but compromises host properties and unintentionally accelerates the formation of microplastics with partial polymer degradation6,8,9. Here we show that by nanoscopically dispersing enzymes with deep active sites, semi-crystalline polyesters can be degraded primarily via chain-end-mediated processive depolymerization with programmable latency and material integrity, akin to polyadenylation-induced messenger RNA decay10. It is also feasible to achieve processivity with enzymes that have surface-exposed active sites by engineering enzyme-protectant-polymer complexes. Poly(caprolactone) and poly(lactic acid) containing less than 2 weight per cent enzymes are depolymerized in days, with up to 98 per cent polymer-to-small-molecule conversion in standard soil composts and household tap water, completely eliminating current needs to separate and landfill their products in compost facilities. Furthermore, oxidases embedded in polyolefins retain their activities. However, hydrocarbon polymers do not closely associate with enzymes, as their polyester counterparts do, and the reactive radicals that are generated cannot chemically modify the macromolecular host. This study provides molecular guidance towards enzyme-polymer pairing and the selection of enzyme protectants to modulate substrate selectivity and optimize biocatalytic pathways. The results also highlight the need for in-depth research in solid-state enzymology, especially in multi-step enzymatic cascades, to tackle chemically dormant substrates without creating secondary environmental contamination and/or biosafety concerns.

Single-chain heteropolymers transport protons selectively and rapidly.

Precise protein sequencing and folding are believed to generate the structure and chemical diversity of natural channels1,2, both of which are essential to synthetically achieve proton transport performance comparable to that seen in natural systems. Geometrically defined channels have been fabricated using peptides, DNAs, carbon nanotubes, sequence-defined polymers and organic frameworks3-13. However, none of these channels rivals the performance observed in their natural counterparts. Here we show that without forming an atomically structured channel, four-monomer-based random heteropolymers (RHPs)14 can mimic membrane proteins and exhibit selective proton transport across lipid bilayers at a rate similar to those of natural proton channels. Statistical control over the monomer distribution in an RHP leads to segmental heterogeneity in hydrophobicity, which facilitates the insertion of single RHPs into the lipid bilayers. It also results in bilayer-spanning segments containing polar monomers that promote the formation of hydrogen-bonded chains15,16 for proton transport. Our study demonstrates the importance of the adaptability that is enabled by statistical similarity among RHP chains and of the modularity provided by the chemical diversity of monomers, to achieve uniform behaviour in heterogeneous systems. Our results also validate statistical randomness as an unexplored approach to realize protein-like behaviour at the single-polymer-chain level in a predictable manner.

Sequence Design of Random Heteropolymers as Protein Mimics.

Random heteropolymers (RHPs) have been computationally designed and experimentally shown to recapitulate protein-like phase behavior and function. However, unlike proteins, RHP sequences are only statistically defined and cannot be sequenced. Recent developments in reversible-deactivation radical polymerization allowed simulated polymer sequences based on the well-established Mayo-Lewis equation to more accurately reflect ground-truth sequences that are experimentally synthesized. This led to opportunities to perform bioinformatics-inspired analysis on simulated sequences to guide the design, synthesis, and interpretation of RHPs. We compared batches on the order of 10000 simulated RHP sequences that vary by synthetically controllable and measurable RHP characteristics such as chemical heterogeneity and average degree of polymerization. Our analysis spans across 3 levels: segments along a single chain, sequences within a batch, and batch-averaged statistics. We discuss simulator fidelity and highlight the importance of robust segment definition. Examples are presented that demonstrate the use of simulated sequence analysis for in-silico iterative design to mimic protein hydrophobic/hydrophilic segment distributions in RHPs and compare RHP and protein sequence segments to explain experimental results of RHPs that mimic protein function. To facilitate the community use of this workflow, the simulator and analysis modules have been made available through an open source toolkit, the RHPapp.

Deep Learning-Enabled Morphometric Analysis for Toxicity Screening Using Zebrafish Larvae.

Toxicology studies heavily rely on morphometric analysis to detect abnormalities and diagnose disease processes. The emergence of ever-increasing varieties of environmental pollutants makes it difficult to perform timely assessments, especially using in vivo models. Herein, we propose a deep learning-based morphometric analysis (DLMA) to quantitatively identify eight abnormal phenotypes (head hemorrhage, jaw malformation, uninflated swim bladder, pericardial edema, yolk edema, bent spine, dead, unhatched) and eight vital organ features (eye, head, jaw, heart, yolk, swim bladder, body length, and curvature) of zebrafish larvae. A data set composed of 2532 bright-field micrographs of zebrafish larvae at 120 h post fertilization was generated from toxicity screening of three categories of chemicals, i.e., endocrine disruptors (perfluorooctanesulfonate and bisphenol A), heavy metals (CdCl2 and PbI2), and emerging organic pollutants (acetaminophen, 2,7-dibromocarbazole, 3-monobromocarbazo, 3,6-dibromocarbazole, and 1,3,6,8-tetrabromocarbazo). Two typical deep learning models, one-stage and two-stage models (TensorMask, Mask R-CNN), were trained to implement phenotypic feature classification and segmentation. The accuracy was statistically validated with a mean average precision >0.93 in unlabeled data sets and a mean accuracy >0.86 in previously published data sets. Such a method effectively enables subjective morphometric analysis of zebrafish larvae to achieve efficient hazard identification of both chemicals and environmental pollutants.

Asymmetric Catalytic Assembly of Triple-Columned and Multilayered Chiral Folding Polymers Showing Aggregation-Induced Emission (AIE).

Unprecedented chiral multilayer folding 3D polymers have been assembled and regulated by uniform and differentiated aromatic chromophore units between naphthyl piers. Screening catalysts, catalytic systems and monomers were proven to be crucial for asymmetric catalytic Suzuki-Miyaura polycouplings for this assembly. X-ray crystallography of the corresponding dimers and trimers revealed the absolute configuration and the intermolecular packing pattern. Up to 61 960 Mw /41 900 Mn and m/z 4317 for polymers and oligomers, as confirmed by gel permeation chromatography (GPC) and MALDI-TOF MS, indicated that these frameworks were composed of multiple stacked layers. The resulting multiple π-assemblies exhibited remarkable optical properties in aggregated states (photoluminescence in solids and aggregation-induced emission in solutions), as well as reversible redox properties in electrochemical performance.

Asymmetric Catalytic Assembly of Triple-Columned and Multilayered Chiral Folding Polymers Showing Aggregation-Induced Emission (AIE).

Invited for the cover of this issue are Guigen Li's groups at Texas Tech University and Nanjing University. The cover artwork shows that chirality patterns exist from universal to molecular levels showing light emission properties. Read the full story of multilayer 3D chirality and its asymmetric catalytic synthesis at 10.1002/chem.202104102.

Sorafenib-Loaded Copper Peroxide Nanoparticles with Redox Balance Disrupting Capacity for Enhanced Chemodynamic Therapy against Tumor Cells.

Chemodynamic therapy (CDT) is a promising hydroxyl radical (•OH)-mediated tumor therapeutic method with desirable tumor specificity and minimal side effects. However, the efficiency of CDT is restricted by the pH condition, insufficient H2O2 level, and overexpressed reductive glutathione (GSH), making it challenging to solve these problems simultaneously to improve the efficacy of CDT. Herein, a kind of polyvinylpyrrolidone-stabilized, sorafenib-loaded copper peroxide (CuO2-PVP-SRF) nanoparticle (NPs) was designed and developed for enhanced CDT against tumor cells through the synergetic pH-independent Fenton-like, H2O2 self-supplying, and GSH depletion strategy. The prepared CuO2-PVP-SRF NPs can be uptaken by 4T1 cells to specifically release Cu2+, H2O2, and SRF under acidic conditions. The intracellular GSH can be depleted by SRF-induced system xc- dysfunction and Cu2+-participated redox reaction, causing the inactivation of GPX4 and generating Cu+. A great amount of •OH was produced in this reducing capacity-disrupted condition by the Cu+-mediated Fenton-like reaction, causing cell apoptosis and lipid hydroperoxide accumulation-induced ferroptosis. They display an excellent 4T1 cell killing outcome through the improved •OH production capacity. The CuO2-PVP-SRF NPs display elevated therapeutic efficiency of CDT and show good promise in further tumor treatment applications.

Discovery of aminothiazole derivatives as novel human enterovirus A71 capsid protein inhibitors.

Enterovirus A71 (EV-A71), one of the major pathogens that causes hand, foot and mouth disease (HFMD), has seriously threatened the health and safety of young children. In this study, aminothiazole derivatives were synthesized and screened against EV-A71 in Rhabdomyosarcoma (RD) cells. The best compound (12s), with a biphenyl group, showed activity against EV-A71 (EC50: 0.27 µM) but also against a series of different human enteroviruses without significant cytotoxicity (CC50 > 56.2 µM). Mechanistic studies including time-of-drug-addition assays, viral entry assays and microscale thermophoresis (MST) experiments, showed that 12s binds to EV-A71 capsid and blocks the binding between the viral protein VP1 and the relevant human scavenger receptor class B member 2 (hSCARB2).

Comprehensive meta-analysis of antibiotic-impregnated bone cement versus plain bone cement in primary total knee arthroplasty for preventing periprosthetic joint infection.

PURPOSE: Antibiotic-loaded bone cement (ALBC) was usually used to prevent periprosthetic joint infection (PJI) in primary total knee arthroplasty (PTKA), but whether to use ALBC or plain bone cement in PTKA remains unclear. We aimed to compare the occurrence rate of PJI using two different cements, and to investigate the efficacy of different antibiotic types and doses administered in preventing surgical site infection (SSI) with ALBC. METHODS: The availability of ALBC for preventing PJI was evaluated by using a systematic review and meta-analysis referring to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Existing articles until December 2021 involving PTKA patients with both ALBC and plain bone cement cohorts were scanned by searching "total knee arthroplasty", "antibiotic-loaded cement", "antibiotic prophylaxis", "antibiotic-impregnated cement" and "antibiotic-laden cement" in the database of PubMed/MEDLINE, Embase, Web of Science and the Cochrane Library. Subgroup analysis included the effectiveness of different antibiotic types and doses in preventing SSI with ALBC. The modified Jadad scale was employed to score the qualities of included articles. RESULTS: Eleven quantitative studies were enrolled, including 34,159 knees undergoing PTKA. The meta-analysis results demonstrated that the use of prophylactic ALBC could significantly reduce the prevalence of deep incisional SSI after PTKA, whereas there was no significant reduction in the rate of superficial incisional SSI. Moreover, gentamicin-loaded cement was effective in preventing deep incisional SSI, and the use of high-dose ALBC significantly reduced the rate of deep incisional SSI after PTKA. Besides, no significant adverse reactions and complications were stated during the use of ALBC in PTKA. CONCLUSION: The preventive application of ALBC during PTKA could reduce the rates of deep PJI. Furthermore, bone cement containing gentamicin and high-dose ALBC could even better prevent deep infection after PTKA. However, the existing related articles are mostly single-center and retrospective studies, and further high-quality ones are needed for confirmation.

Backbone-Photodegradable Polymers by Incorporating Acylsilane Monomers via Ring-Opening Metathesis Polymerization.

Materials capable of degradation upon exposure to light hold promise in a diverse range of applications including biomedical devices and smart coatings. Despite the rapid access to macromolecules with diverse compositions and architectures enabled by ring-opening metathesis polymerization (ROMP), a general strategy to introduce facile photodegradability into these polymers is lacking. Here, we report copolymers synthesized via ROMP that can be degraded by cleaving the backbone in both solution and solid states under irradiation with a 52 W, 390 nm Kessil LED to generate heterotelechelic low-molecular-weight fragments. To the best of our knowledge, this work represents the first instance of the incorporation of acylsilanes into a polymer backbone. Mechanistic investigation of the degradation process supports the intermediacy of an α-siloxy carbene, formed via a 1,2-photo Brook rearrangement, which undergoes insertion into water followed by cleavage of the resulting hemiacetal.

Removal of sticky silicone oil adhered to the retinal surface: comparison of methodological safety and effectiveness.

PURPOSE: To compare safety and effectiveness among methods to remove sticky silicone oil bubbles adhered to the retinal surface. METHODS: This retrospective nonrandomised case series included 14 eyes of 14 patients who had sticky silicone oil residue during silicone oil removal surgery. For small sticky silicone oil bubbles (< 2-disc diameter), aspiration was performed with a 23-gauge vitreous cutter. Residual tiny oil bubbles were then removed with a silicone-tipped flute needle or internal limiting membrane (ILM) peeling. For large sticky silicone oil bubbles (≥ 2-disc diameter) that could not be removed with a 23-gauge vitreous cutter, we devised a more efficient active removal method involving a modified 22-gauge venous indwelling cannula device. RESULTS: The mean preoperative best-corrected visual acuity (BCVA; logarithm of the minimum angle of resolution [logMAR]) significantly improved from 1.28 ± 0.63 logMAR to 0.77 ± 0.58 logMAR (p = 0.014). The postoperative BCVA and improvement in BCVA were significantly better in the ILM peeling group than in the non-ILM peeling group (p = 0.004 and p = 0.045, respectively). Postoperative complications included residual sticky silicone oil bubbles in seven eyes without ILM peeling (50.0%), retinal neuroepithelial layer damage in two eyes (14.3%), and temporary hypotony in five eyes (35.7%). CONCLUSION: Various methods can safely and efficiently remove sticky silicone oil bubbles adhered to the retinal surface. A 22-gauge venous indwelling cannula enabled simple and safe removal of large sticky silicone oil bubbles, while small residual sticky silicone oil bubbles could be completely removed by ILM peeling.

Full Digital Workflow of Nasoalveolar Molding Treatment in Infants With Cleft Lip and Palate.

OBJECTIVES: The aim of this pilot study was to illustrate the feasibility of a full digital workflow to design and manufacturing a consecutive series of customized nasoalveolar molding (NAM) appliances in advance for presurgical unilateral and bilateral cleft lip and palate (CLP) treatment. METHODS: The full digital workflow consisted of acquisition of 3D image data of an infant's maxilla by using intraoral scanner (TRIOS; 3Shape, Copenhagen, Denmark); the initial data were imported into an appropriate computer-aided design (CAD) software environment, the digital model was virtual modified to achieve a harmonic alveolar arch, and generated a consecutive of digital models of each movement stage; the digital model of NAM appliance was designed based on the virtual modified model; bio-compatible material MED610 was used to manufacturing the real NAM appliances by 3D printing. A consecutive series of NAM appliances was delivered to CLP infant before lip surgery. RESULTS: Intraoral scanning was harmless and safer than conventional impression technique for CLP infants. The CAD/3D printing procedures allowed a series of NAM appliances to be designed and manufactured in advance. The clinical results showed that this full digital workflow was efficient, viable and able to estimate the treatment objective. By the end of presurgical NAM treatment, the malposition alveolar segments had been aligned normally, the surrounding soft tissues repositioned. CONCLUSIONS: The full digital workflow presented has provided the potential for presurgical NAM treatment of infants with cleft lip and palate. Intraoral scanning served as a starting point, so subsequent virtual treatment planning and CAD/3D printing procedures could realize the full digital workflow, a whole series of customized NAM appliances was manufactured in advance. This method brings the benefits of safety, affectivity and time-saving.

Inducing Intermediates in Biotransformation of Natural Polyacetylene and A Novel Spiro-γ-Lactone from Red Ginseng by Solid Co-Culture of Two Gut Chaetomium globosum and The Potential Bioactivity Modification by Oxidative Metabolism.

The ω-hydroxyl-panaxytriol (1) and ω-hydroxyl-dihydropanaxytriol (2)-are rare examples of polyacetylene metabolism by microbial transformation, and these new metabolites (1, 2) from fermented red ginseng (FRG) by solid co-culture induction of two Chaetomium globosum should be the intermediates of biotransformation of panaxylactone (metabolite A). The metabolic pathway of panaxylactone was also exhibited. The ingredients of red ginseng (RG) also induced the production of rare 6/5/5 tricyclic ring spiro-γ-lactone skeleton (3). The ω-hydroxylation of new intermediates (1, 2) decreases cytotoxicity and antifungal activity against C. globosum compared with that of its bioprecursor panaxytriol. Additionally, compounds 1 and 2 indicated obvious inhibition against nitric oxide (NO) production, with ratios of 44.80 ± 1.37 and 23.10 ± 1.00% at 50 µM. 1 has an equivalent inhibition of NO production compared with the positive drug. So, the microbial biotransformation that occurred in FRG fermented by gut C. globosum can change the original bioactivity of polyacetylene, which gave a basis about the metabolic modification of red ginseng by intestinal fungus fermentation.

Gingival bleeding and calculus among 12-year-old Chinese adolescents: a multilevel analysis.

BACKGROUND: Gingivitis is a common oral health problem, and untreated gingivitis can progress to periodontitis. The objectives of this study were to (1) explore associated factors of gingival bleeding and calculus among 12-year-old adolescents; (2) find predictive models for gingivitis management. METHODS: Four thousand five hundred twenty-five subjects aged 12 in Sichuan Province were investigated. The questionnaire and clinical examination were applied in schools, and two-level logistic regression models were constructed to interpret the effect of individual and contextual factors on Chinese adolescents' gingival bleeding and calculus. RESULTS: 46.63% (95%CI: 40.71, 51.60) and 66.94% (95%CI: 56.85, 67.45) of the subjects presented gingival bleeding and calculus, respectively. For the gingival bleeding cases, the model showed the significant associated indicators were hukou (OR = 0.61, 95% CI: 0.52-0.72), family size (OR = 1.41, 95% CI: 1.19-1.68), parental educational level (father: OR = 0.53, 95% CI: 0.45-0.63; mother: OR = 0.71, 95% CI: 0.59-0.86), tooth-brushing frequency (OR = 0.35, 95% CI: 0.26-0.48), dental floss use (OR = 0.58, 95% CI: 0.41-0.83), sugar-containing drink consumption (OR = 2.11, 95% CI: 1.80-2.49), and dental visit (OR = 1.44, 95% CI: 1.19-1.74). It also confirmed that gender (OR = 1.32, 95% CI: 1.13-1.54), hukou (OR = 0.69, 95% CI: 0.59-0.82), family size (OR = 1.34, 95% CI: 1.12-1.59), parental educational level (father: OR = 0.46, 95% CI: 0.39-0.54; mother: OR = 0.65, 95% CI: 0.59-0.82), tooth-brushing frequency (OR = 0.57, 95% CI: 0.42-0.78), dental floss use (OR = 0.66, 95% CI: 0.48-0.90) and sugar-containing drink consumption (OR = 1.30, 95% CI: 1.11-1.53) were associated factors for dental calculus. CONCLUSIONS: Gingival bleeding and calculus were common in western Chinese adolescents. Socio-demographic factors including gender, hukou and family factors are strong determinants of gingival health in Chinese adolescents. In addition, health-related lifestyle behaviors such as healthy diet, good hygiene care and more dental visits are good predictors of better gingival status.

Brick tea consumption is a risk factor for dental caries and dental fluorosis among 12-year-old Tibetan children in Ganzi.

Brick tea contains high concentration of fluoride. The aim of the present work was to explore whether and how the brick tea is a risk factor for dental caries and dental fluorosis among Tibetan children in Ganzi. A cross-sectional study was conducted with 368 12-year-old Tibetan children in Ganzi. Dental caries was measured by DMFT index, and dental fluorosis severity was measured by Dean's Index. Community Fluorosis Index was used to estimate public health significance of dental fluorosis. Oral health-related behaviors and awareness, dietary habits and socioeconomic status were determined by a questionnaire. Bivariate and multivariate analyses were used to determine risk factors associated with dental caries and dental fluorosis. Dental caries prevalence was 37.50%, mean DMFT was 0.84 ± 1.53, while dental fluorosis prevalence was 62.23%. Community Fluorosis Index was 1.35, indicating a medium prevalent strength of dental fluorosis. Dental fluorosis was associated with mother's regular consumption of brick tea and residence altitude, and dental caries was associated with mother's regular consumption of brick tea. Mother's regular consumption of brick tea was a risk factor for both dental fluorosis and dental caries among children. Reducing mother's brick tea consumption during pregnancy and lactation may improve oral health status of their children.

Structural equation modelling for associated factors with dental caries among 3-5-year-old children: a cross-sectional study.

BACKGROUND: The aim of the current study was to explore the factors influencing dental caries among 3-5-year-old children in Sichuan Province and the interrelationship between these factors using structural equation modelling (SEM). METHODS: A cross-sectional study was conducted among 2746 3-5-year-old children in Sichuan Province. Examination of caries was conducted on all children and a questionnaire was answered by the children's caregiver. SEM alternative models were constructed to interpret the intricate relationships between socio-economic status (SES), caregiver's oral health knowledge, attitudes, children's oral health behaviours and children's dental caries. RESULT: The results showed that dental caries were significantly associated with dietary behaviours (ß = 0.11, SE = 0.03, P = 0.001, BC 95% CI =0.05/0.18) and SES (ß = - 0.17, SE = 0.03, P<0.001, BC 95% CI = -0.23/- 0.10) directly, While the indirect effect of SES on dmft is in an opposite direction (ß = 0.08, SE = 0.02, BC 95% CI = 0.04/0.12). CONCLUSION: We found that unhealthy dietary behaviours increased the prevalence of dental caries. However, oral health knowledge and attitude failed to affect dietary behaviour in this model. This result warns that oral health education should strengthen feeding-related knowledge. Meanwhile, it also reminds that it is easier known than done. Future oral health education should focus on exploring a more effective way for the public to turn knowledge into action.

Environmental Stability of Plasmonic Biosensors Based on Natural versus Artificial Antibody.

Plasmonic biosensors based on the refractive index sensitivity of localized surface plasmon resonance (LSPR) are considered to be highly promising for on-chip and point-of-care biodiagnostics. However, most of the current plasmonic biosensors employ natural antibodies as biorecognition elements, which can easily lose their biorecognition ability upon exposure to environmental stressors (e.g., temperature and humidity). Plasmonic biosensors relying on molecular imprints as recognition elements (artificial antibodies) are hypothesized to be an attractive alternative for applications in resource-limited settings due to their excellent thermal, chemical, and environmental stability. In this work, we provide a comprehensive comparison of the stability of plasmonic biosensors based on natural and artificial antibodies. Although the natural antibody-based plasmonic biosensors exhibit superior sensitivity, their stability (temporal, thermal, and chemical) was found to be vastly inferior to those based on artificial antibodies. Our results convincingly demonstrate that these novel classes of artificial antibody-based plasmonic biosensors are highly attractive for point-of-care and resource-limited conditions where tight control over transport, storage, and handling conditions is not possible.

Catalytically Active Bacterial Nanocellulose-Based Ultrafiltration Membrane.

Large quantities of highly toxic organic dyes in industrial wastewater is a persistent challenge in wastewater treatment processes. Here, for highly efficient wastewater treatment, a novel membrane based on bacterial nanocellulose (BNC) loaded with graphene oxide (GO) and palladium (Pd) nanoparticles is demonstrated. This Pd/GO/BNC membrane is realized through the in situ incorporation of GO flakes into BNC matrix during its growth followed by the in situ formation of palladium nanoparticles. The Pd/GO/BNC membrane exhibits highly efficient methylene orange (MO) degradation during filtration (up to 99.3% over a wide range of MO concentrations, pH, and multiple cycles of reuse). Multiple contaminants (a cocktail of 4-nitrophenol, methylene blue, and rhodamine 6G) can also be effectively treated by Pd/GO/BNC membrane simultaneously during filtration. Furthermore, the Pd/GO/BNC membrane demonstrates stable flux (33.1 L m-2 h-1 ) under 58 psi over long duration. The novel and robust membrane demonstrated here is highly scalable and holds a great promise for wastewater treatment.