Sheep Wool Humidity under Electron Irradiation Affects Wool Sorptivity towards Co(II) Ions.

The effect of humidity on sheep wool during irradiation by an accelerated electron beam was examined. Each of the samples with 10%, 53%, and 97% relative humidity (RH) absorbed a dose of 0, 109, and 257 kGy, respectively. After being freely kept in common laboratory conditions, the samples were subjected to batch Co(II) sorption experiments monitored with VIS spectrometry for different lapses from electron beam exposure. Along with the sorption, FTIR spectral analysis of the wool samples was conducted for cysteic acid and cystine monoxide, and later, the examination was completed, with pH measuring 0.05 molar KCl extract from the wool samples. Besides a relationship to the absorbed dose and lapse, the sorptivity results showed considerable dependence on wool humidity under exposure. When humidity was deficient (10% RH), the sorptivity was lower due to limited transformation of cystine monoxide to cysteic acid. The wool pre-conditioned at 53% RH, which is the humidity close to common environmental conditions, demonstrated the best Co(II) sorptivity in any case. This finding enables the elimination of pre-exposure wool conditioning in practice. Under excessive humidity of 97% RH and enough high dose of 257 kGy, radiolysis of water occurred, deteriorating the sorptivity. Each wool humidity, dose, and lapse showed a particular scenario. The time and humidity variations in the sorptivity for the non-irradiated sample were a little surprising; despite the absence of electron irradiation, relevant results indicated a strong sensitivity to pre-condition humidity and lapse from the start of the monitoring.

Adsorption and Desorption Characteristics of Total Flavonoids from Acanthopanax senticosus on Macroporous Adsorption Resins.

We examined the application of six different resins with the aim of selecting a macroporous resin suitable for purifying Acanthopanax senticosus total flavonoids (ASTFs) from Acanthopanax senticosus crude extract (EAS) by comparing their adsorption/desorption capacities, which led to the selection of HPD-600. Research on the adsorption mechanism showed that the adsorption process had pseudo-second-order kinetics and fit the Freundlich adsorption model. Moreover, the analysis of thermodynamic parameters indicated that the adsorption process is spontaneous and endothermic. The optimal conditions for purification of ASTFs were determined as sample pH of 3, 60% ethanol concentration, and 3 BV·h-1 flow rate, for both adsorption and desorption, using volumes of 2.5 and 4 BV, respectively. The application of macroporous resin HPD-600 to enrich ASTFs resulted in an increase in the purity of total flavonoids, from 28.79% to 50.57%. Additionally, the antioxidant capacity of ASTFs was higher than that of EAS, but both were lower than that of L-ascorbic acid. The changes in ASTFs compositions were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), with the results illustrating that the levels of seven major flavonoids of ASTFs were increased compared to that in the crude extract.

Adsorption of Cd to TiO2-NPs Forms Low Genotoxic AGGREGATES in Zebrafish Cells.

The aquatic environment is involved in the pollutants spreading mechanisms, including nanomaterials and heavy metals. The aims of this study were to assess the in vivo genotoxicity of Cd (1 mg/L) and to investigate the genomic effects generated by its co-exposure with TiO2-NPs (10 µg/L). The study was performed using zebrafish as a model for 5, 7, 14, 21, and 28 days of exposure. The genotoxic potential was assessed by three experimental approaches: DNA integrity, degree of apoptosis, and molecular alterations at the genomic level by genomic template stability (% GTS) calculation. Results showed an increased in DNA damage after Cd exposure with a decrease in % GTS. The co-exposure (TiO2-NPs + Cd) induced a no statistically significant loss of DNA integrity, a reduction of the apoptotic cell percentage and the recovery of genome stability for prolonged exposure days. Characterization and analytical determinations data showed Cd adsorption to TiO2-NPs, which reduced free TiO2-NPs levels. The results of our study suggest that TiO2-NPs could be used for the development of controlled heavy metal bioremediation systems.

Separation of biobutanol from ABE fermentation broth using lignin as adsorbent: A totally sustainable approach with effective utilization of lignocellulose.

Adsorption is considered to be a promising butanol recovery method for solving the issue of inhibition in the ABE (acetone-butanol-ethanol) fermentation. As a byproduct in the second generation biobutanol industry, lignin was found to be a good adsorbent for the butanol enrichment. It is conducive to the full utilization of renewable lignocellulose biomass resource. Kinetic and equilibrium experiments indicated that lignin had a satisfactory adsorption rate and capacity that are comparable to those of many synthetic materials. Multicomponent adsorption experiments revealed that lignin had higher adsorption selectivity toward butanol than that of ethanol and acetone. The adsorption capacity of lignin for butanol first increased and then gradually decreased with increasing temperature. And maximum adsorption capacity reached 304.66 mg g-1 at 313 K. The inflection point of temperature is close to the ABE fermentation temperature of 310 K. The condensed butanol by desorption was 145 g L-1, with a satisfying regeneration performance. 1H NMR and FT-IR spectra indicated that the aromatic units of lignin formed π-systems with A/B/E. The π-system is particularly significant for butanol due to its longer hydrocarbon chain. These results could contribute to the emerging lignin-based materials for butanol separation.

Comparison of functional properties of porous starches produced with different enzyme combinations.

To obtain porous starch granules with higher absorption capacities, three types of enzyme combinations were adopted to modify wheat and maize starches: (1) sequential α-amylase (AA) â†’ glucoamylase (GA); (2) sequential branching enzyme (BE) â†’ GA; and (3) sequential AA→BE→GA. The results indicated that AA→BE→GA treatment had a most optimal influence on porous starches. Compared to AA→GA and BE→GA, the mesopores in wheat starch granules treated with AA→BE→GA decreased by 52.82 and 48.70%, respectively. Conversely, the macropores increased by 216.68 and 138.18%, respectively. While for maize starch, the percentages of mesopores and macropores hardly changed after three enzyme combinations. Comparing the three enzyme treatments showed that pore volume (0.005 and 0.007 cm3/g) and pore size (36.35 and 26.54 nm) were largest in the AA→BE→GA treated wheat and maize starches, respectively. Compared to the AA→GA and BE→GA, the adsorption capacities for oil, dye and heavy metal ions, wheat starch treated with AA→BE→GA increased by 46.61 and 242.33%, and 44.52 and 134.41%, and 28.83 and 271.72%, respectively. Correspondingly, that of maize starch increased by 29.71 and 133.29%, and 42.92 and 79.93%, and 28.16 and 161.43%, respectively. These results may provide a new and valuable enzyme combination for optimising porous starch granules with higher absorption capacities.

Modeling the Effect of DAV132, a Novel Colon-Targeted Adsorbent, on Fecal Concentrations of Moxifloxacin and Gut Microbiota Diversity in Healthy Volunteers.

To prevent antibiotic-induced perturbations on gut microbiota, DAV132, a novel colon-targeted adsorbent, which sequesters antibiotic residues in the lower gastrointestinal tract, was developed. We built an integrated pharmacological model of how DAV132 reduces fecal free moxifloxacin and preserves gut microbiota. We used plasma and fecal free moxifloxacin concentrations, and Shannon diversity index from 16S ribosomal RNA gene metagenomics analysis of fecal microbiota, of 143 healthy volunteers assigned randomly to receive moxifloxacin only, or with 10 DAV132 dose regimens, or to a control group. We modeled reduced fecal moxifloxacin concentrations using a transit model for DAV132 kinetics and a Michaelis-Menten model with an effect of the amount of activated charcoal on adsorption efficacy. Changes in moxifloxacin-induced perturbations on gut microbiota diversity were then quantified through a turnover model with the Emax model. With the developed model, the efficiency of pharmacokinetic antagonism and its consequences on gut microbiota diversity were quantified.

Preparation and characterization of rice husk adsorbents for phenol removal from aqueous systems.

Rice husk is a base adsorbent for pollutant removal. It is a cost-effective material and a renewable resource. This study provides the physicochemical characterization of chemically and thermally treated rice husk adsorbents for phenol removal from aqueous solutions. We revealed new functional groups on rice husk adsorbents by Fourier transform infrared spectroscopy, and observed major changes in the pore structure (from macro-mesopores to micro-mesopores) of the developed rice husk adsorbents using scanning electron microscopy. Additionally, we studied their surface area and pore size distribution, and found a greater enhancement of the morphological structure of the thermally treated rice husk compared with that chemically treated. Thermally treated adsorbents presented a higher surface area (24-201 m2.g-1) than those chemically treated (3.2 m2.g-1). The thermal and chemical modifications of rice husk resulted in phenol removal efficiencies of 36%-64% and 28%, respectively. Thus, we recommend using thermally treated rice husk as a promising adsorbent for phenol removal from aqueous solutions.

Retention of E. coli and water on the skin after liquid contact.

The frequent contact people have with liquids containing pathogenic microorganisms provides opportunities for disease transmission. In this work, we quantified the transfer of bacteria-using E. coli as a model- from liquid to skin, estimated liquid retention on the skin after different contact activities (hand immersion, wet-cloth and wet-surface contact), and estimated liquid transfer following hand-to-mouth contacts. The results of our study show that the number of E. coli transferred to the skin per surface area (n [E. coli/cm2]) can be modeled using n = C (10-3.38+h), where C [E. coli/cm3] is the concentration of E. coli in the liquid, and h [cm] is the film thickness of the liquid retained on the skin. Findings from the E. coli transfer experiments reveal a significant difference between the transfer of E. coli from liquid to the skin and the previously reported transfer of viruses to the skin. Additionally, our results demonstrate that the time elapsed since the interaction significantly influences liquid retention, therefore modulating the risks associated with human interaction with contaminated liquids. The findings enhance our understanding of liquid-mediated disease transmission processes and provide quantitative estimates as inputs for microbial risk assessments.

Improvement of lipase biochemical properties via a two-step immobilization method: Adsorption onto silicon dioxide nanoparticles and entrapment in a polyvinyl alcohol/alginate hydrogel.

In this study, the factors affecting lipase adsorption onto SiO2 nanoparticles including SiO2 nanoparticles amounts (8, 19 and 30 mg/mL), lipase concentrations (30, 90 and 150 µg/mL), adsorption temperatures (5, 20 and 35 °C) and adsorption times (1, 12.5 and 24 h) were optimized using central composite design. The optimal conditions were determined as a SiO2 nanoparticles amount of 8.5-14 mg/ml, a lipase concentration of 106-116 µg/mL, an adsorption temperature of 20 °C and an adsorption time of 12.5 h, which resulted in a specific activity and immobilization efficiency of 20,000 (U/g protein) and 60 %, respectively. The lipase adsorbed under optimal conditions (SiO2-lipase) was entrapped in a PVA/Alg hydrogel, successfully. FESEM and FTIR confirmed the two-step method of lipase immobilization. The entrapped SiO2-lipase retained 76.5 % of its initial activity after 30 days of storage at 4 °C while adsorbed and free lipase retained only 43.4 % and 13.7 %, respectively. SiO2-lipase activity decreased to 34.43 % after 10 cycles of use, while the entrapped SiO2-lipase retained about 64.59 % of its initial activity. Compared to free lipase, the Km values increased and decreased for SiO2-lipase and entrapped SiO2-lipase, respectively. Vmax value increased for both SiO2-lipase and entrapped SiO2-lipase.

The molecular insights into protein adsorption on hematite surface disclosed by in-situ ATR-FTIR/2D-COS study.

Proteins are of ubiquitous interest in the Life Sciences but are of interest in the Geosciences as well because of the significant role these compounds play in the biogeochemical cycling of trace and nutrient elements. Structural changes resulting from the adsorption of proteins onto mineral surfaces may alter protein biological function and other environmental interactions. Iron oxides are major sinks of a range of environmental elements including organic compounds. In this study, the adsorption of the broadly studied model protein BSA onto the hematite mineral surface was characterized as a function of pH, ionic strength, and BSA concentration using in-situ Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. BSA lost the α-helix and gain ß-sheets in the secondary structure during adsorption on hematite. BSA adsorption was maximum at pH 5, a value close to the BSA isoelectric point (~ pH 5), and lower at pH 4 and pH 7. Increasing ionic strength decreased to total BSA adsorption. Two-dimensional correlation spectroscopy analysis of the ATR-FTIR spectra revealed that higher initial BSA concentration and the consequent higher BSA surface loading enhanced BSA adsorption by protein-protein interaction, which less ordered structures changes into more compact forms decrease, hence compacting the structural arrangement and could promoting multilayers/aggregation formation on the mineral surface. The activity of enzymes following adsorption on mineral surfaces requires further study.

Porous starches modified with double enzymes: Structure and adsorption properties.

To explore an effective enzyme combination instead of a common enzyme method, sequential α-amylase and glucoamylase, a method of sequential glycosyltransferase and branching enzyme was chosen to compare the macroscopic features, structure characteristics, porosity characteristics and adsorption quantity of potato, corn, wheat and sweet potato starches. The results indicated that after enzyme treatment, the relative crystallinity of potato, corn, wheat and sweet potato starches increased. Moreover, amylose levels decreased, while pore size and volume, and specific surface area increased after sequential glycosyltransferase and branching enzyme. In terms of pore size, sequential α-amylase and glucoamylase produced abundant mesopores (2-50 nm), whereas sequential glycosyltransferase and branching enzyme developed much more macropores (>50 nm). The adsorption quantities of the starch obtained with sequential glycosyltransferase and branching enzyme were about 2 folds higher than that of the starch obtained with sequential α-amylase and glucoamylase. Therefore, the sequential glycosyltransferase and branching enzyme may be an ideal method to create porous starch as a desirable green adsorbent for industries.

Comparison of Drug Release and Adsorption under Supersaturating Conditions for Ordered Mesoporous Silica with Indomethacin or Indomethacin Methyl Ester.

Incomplete drug release from mesoporous silica systems has been observed in several studies. This work aims to increase the understanding of this phenomenon by investigating the mechanism of drug-silica interactions and adsorption behavior from supersaturated aqueous solutions of two similar drug molecules with different hydrogen bonding capabilities. Drug-silica interactions between indomethacin or its methyl ester and SBA-15 were investigated using spectroscopic techniques (infrared, fluorescence and X-ray photoelectron) and adsorption experiments. The results demonstrate that the predominant mechanism of interaction of both drugs with silica is hydrogen bonding between drug acceptor carbonyl groups with donor groups on the silica surface. The presence of a drug hydrogen bond donor group did not enhance drug adsorption. No evidence was obtained for drug adsorption through nonspecific hydrophobic interactions. Drug adsorption onto the silica surface was investigated under supersaturating conditions through the generation of adsorption isotherms. Similar adsorption isotherms were observed for each compound when the concentration scale was normalized to the drug amorphous solubility. In other words, the equilibrium between the drug adsorbed on the silica surface and free drug in solution was related to the drug activity in solution. The high tendency of the drug to adsorb when the solution is supersaturated was, in turn, found to limit the extent of drug release during dissolution under nonsink conditions. Thus, adsorption provides an explanation for incomplete drug release.

LncRNA HOTTIP promotes proliferation and inhibits apoptosis of gastric carcinoma cells via adsorbing miR-615-3p.

OBJECTIVE: To explore the role of long-noncoding ribonucleic acid HOXA transcript at the distal tip (lncRNA HOTTIP) in the proliferation and apoptosis of gastric carcinoma cells. MATERIALS AND METHODS: The expressions of lncRNA HOTTIP in gastric carcinoma cell lines MGC-803, HGC-27, SNU-1, and SGC-7901 and normal gastric mucosa cell line RGM-1 were detected by real-time fluorescence quantitative polymerase chain reaction (PCR) and compared. The effects of lncRNA HOTTIP on proliferation and apoptosis of gastric carcinoma cells were detected by cell counting kit-8 (CCK-8), colony formation assay, and flow cytometry, respectively. StarBase v2.0 website was adopted to predict the relationship between lncRNA HOTTIP and target miRNAs. Dual-Luciferase reporter assay was performed to verify the sponge effect of lncRNA HOTTIP on miR-615-3p. CCK-8 experiment was conducted to detect its effect on proliferation of gastric carcinoma cells after co-silencing lncRNA HOTTIP and miR-615-3p. RESULTS: LncRNA HOTTIP was highly expressed in gastric carcinoma cell lines MGC-803, HGC-27, SNU-1, and SGC-7901 than in normal gastric mucosa cell line RGM-1. After knockdown of lncRNA HOTTIP, the proliferation function of gastric carcinoma cells was markedly weakened, and the proportion of apoptotic cells increased. LncRNA HOTTIP was able to adsorb miR-615-3p via a sponge effect. Notably, knockdown of miR-615-3p restored the effect of silenced lncRNA HOTTIP on the proliferation function of gastric carcinoma cells. CONCLUSIONS: LncRNA HOTTIP is highly expressed in gastric carcinoma cells. It affects cell proliferation and apoptosis in gastric carcinoma by adsorbing miR-615-3p via a sponge effect.

TGFß activity released from platelet-rich fibrin adsorbs to titanium surface and collagen membranes.

Platelet-rich fibrin (PRF) contains a broad spectrum of bioactive molecules that can trigger several cellular responses. However, these molecules along with their upstream responses remain mostly uninvestigated. By means of proteomics we revealed that PRF lysates contain more than 650 proteins, being TGF-ß one of the few growth factors found. To uncover the major target genes regulated by PRF lysates, gingival fibroblasts were exposed to lysates obtained from PRF membranes followed by a whole genome array. We identified 51 genes strongly regulated by PRF including IL11, NOX4 and PRG4 which are characteristic TGF-ß target genes. RT-PCR and immunoassay analysis confirmed the TGF-ß receptor I kinase-dependent increased expression of IL11, NOX4 and PRG4. The PRF-derived TGF-ß activity was verified by the translocation of Smad2/3 into the nucleus along with the increased phosphorylation of Smad3. Considering that PRF is clinically used in combination with dental implants and collagen membranes, we showed here that PRF-derived TGF-ß activity adsorbs to titanium implants and collagen membranes indicated by the changes in gene expression and immunoassay analysis. Our study points towards TGF-ß as major target of PRF and suggest that TGF-ß activity released by PRF adsorbs to titanium surface and collagen membranes.

Comparison of plasma exchange, double plasma molecular adsorption system, and their combination in treating acute-on-chronic liver failure.

OBJECTIVE: Our objective was to compare the effectiveness of nonbiological artificial liver (NBAL) support, particularly short-term (28-day) survival rates, in patients who underwent treatment using double plasma molecular adsorption system (DPMAS), plasma exchange (PE), or combined PE+DPMAS, in addition to comprehensive physical treatment for different stages of acute-on-chronic liver failure (ACLF). METHODS: We retrospectively reviewed clinical data of 135 patients with ACLF who received NBAL treatment between November 2015 and February 2019. The patients were categorized into PE, DPMAS, and PE+DPMAS groups. Short-term effectiveness of treatment was assessed and compared based on selected clinical findings, laboratory parameters, and liver function markers. RESULTS: Coagulation function improved significantly in all groups after treatment. In the PE and PE+DPMAS groups, prothrombin time decreased to different degrees, whereas plasma thromboplastin antecedent increased significantly after treatment. White blood cell counts increased and platelet counts decreased in all groups after treatment. The model for end-stage liver disease score, Child-Pugh grade, systematic inflammatory syndrome score, and sepsis-related organ failure score decreased in all three groups after treatment. CONCLUSIONS: PE, DPMAS, and PE+DPMAS improved disease indicators in all patients with ACLF. The combined treatment improved the short-term effectiveness of treatment, especially in patients with mild ACLF.

Removal mechanism of Pb(II) by Penicillium polonicum: immobilization, adsorption, and bioaccumulation.

Currently, lead (Pb) has become a severe environmental pollutant and fungi hold a promising potential for the remediation of Pb-containing wastewater. The present study showed that Penicillium polonicum was able to tolerate 4 mmol/L Pb(II), and remove 90.3% of them in 12 days through three mechanisms: extracellular immobilization, cell wall adsorption, and intracellular bioaccumulation. In this paper. the three mechanisms were studied by Raman, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The results indicated that Pb(II) was immobilized as lead oxalate outside the fungal cell, bound with phosphate, nitro, halide, hydroxyl, amino, and carboxyl groups on the cell wall, precipitated as pyromorphite [Pb5(PO4)3Cl] on the cell wall, and reduced to Pb(0) inside the cell. These combined results provide a basis for additionally understanding the mechanisms of Pb(II) removal by P. polonicum and developing remediation strategies using this fungus for lead-polluted water.

Preparation and characterization of cyclodextrin nanosponges for organic toxic molecule removal.

Cyclodextrin-based nanosponges (CD-NS) are considered as safe and biocompatible systems for removing toxic molecules from the body. Rapid removal of toxic molecules that are formed in the body from certain food constituents, is relevant especially for patients affected by chronic kidney disease. Within the scope of this study, innovative cyclodextrin polymers were synthesized to form nanosponges able to remove indole, before it could form the toxic indoxyl sulfate in the body. Furthermore, in vivo studies were carried out using the two optimal CD-NS formulations by assessing physicochemical properties, stability, indole adsorption capacity and in vitro cytotoxicity. NS prepared from ß-cyclodextrin cross-linked with toluene diisocyanate was found to be the most effective NS with an in vitro indole adsorption capacity of over 90%. In addition, this derivative was more stable in gastrointestinal media. Animal studies further revealed that oral CD-NSs did not tend to accumulate and damage gastrointestinal tissues and are excreted from the GI tract with minimal absorption. In conclusion, this study suggests that CD-NS formulations are effective and safe in removing toxic molecules from the body. Their potential use in veterinary or human medicine could reduce dialysis frequency and avoid hepatic and cardiac toxicity avoiding the indole formation.

Study of Short Peptide Adsorption on Solution Dispersed Inorganic Nanoparticles Using Depletion Method.

Fundamentals of inorganic-organic interactions are critically important in the discovery and development of novel biointerfaces amenable for utilization in biotechnology and medicine. Recent studies indicate that proteins interact with surfaces through limited adsorption sites. Protein fragments such as amino acids and peptides can be used for interaction modeling between complex biological macromolecules and inorganic surfaces. During the last three decades, many valid and sensitive methods have been developed to measure the physical chemistry fundamentals of those interactions: isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), quartz crystal microbalance (QCM), total internal reflection fluorescence (TIRF), and attenuated total reflectance spectroscopy (ATR). The simplest and most affordable technique for the measurement of adsorption is the depletion method, where the change in sorbate concentration (depletion) after contact with solution-dispersed sorbent is calculated and assumed to be adsorbed. Adsorption isotherms based on depletion data provide all basic physicochemical data. However, adsorption from solutions requires longer equilibration times due to kinetic restrictions and sorbents with a high specific surface area, making it almost inapplicable to macroscopic fixed plane surfaces. Moreover, factors such as the instability of sols, nanoparticle aggregates, sorbent crystallinity, nanoparticle size distribution, pH of the solution, and competition for adsorption, should be considered while studying adsorbing peptides. Depletion data isotherm construction provides comprehensive physical chemistry data for literally every soluble sorbate yet remains the most accessible methodology, as it does not require expensive setups. This article describes a basic protocol for the experimental study of peptide adsorption on inorganic oxide and covers all critical points that affect the process.

Selective Entropy Gain-Driven Adsorption of Nanospheres onto Spherical Bacteria Endows Photodynamic Treatment with Narrow-Spectrum Activity.

Narrow-spectrum antimicrobials specifically eradicate the target pathogens but suffer from significantly lagging development. Photodynamic therapy eliminates cells with reactive oxygen species (ROS) generated upon light irradiation but is intrinsically a wide-spectrum modality. We herein converted photodynamic therapy into a narrow-spectrum modality by taking advantage of a previously unnoticed physics recognition pathway. We found that negatively charged nanospheres undergo selective entropy gain-driven adsorption onto spherical bacteria, but not onto rod-like bacteria. This bacterial morphology-targeting selectivity, combined with the extremely limited effective radii of action of ROS, enabled photodynamic nanospheres to kill >99% of inoculated spherical bacteria upon light irradiation and <1% of rod-like bacteria under comparable conditions, indicative of narrow-spectrum activity against spherical bacteria. This work unveils the bacterial morphology selectivity in the adsorption of negatively charged nanospheres and suggests a new approach for treating infections characterized by overthriving spherical bacteria in niches naturally dominated by rod-like bacteria.

Sensing molecular organizational changes through the catalytic activity of acetylcholinesterase from erythrocyte membranes in Langmuir-Blodgett films.

Langmuir films prepared from bovine erythrocyte membranes (LFBEM) were studied and transferred to alkylated glasses (Langmuir-Blodgett films, LBBEM) in order to assess the effects of membrane molecular packing on Bovine Erythrocyte Acetylcholinesterase (BEA) catalytic activity. Surface pressure (π) vs Area isotherms showed three 2D-transitions at ~7, ~18 and ~44 mN/m and a collapse pressure at πc = 49 mN/m. The 0-12-0 mN/m compression-decompression cycles resulted reversible while those 0-40-0 mN/m exhibited a significant hysteresis. Taken together, EFM, BAM and AFM images and the stability of the film after 3C-D cycles, we can suggest that over the air-water interface as well as over the silanized glass substrate the surface is mostly covered by a monolayer with a few particles dispersed. Acetylthiocholine hydrolysis was assayed with BEA in bovine erythrocyte membrane suspensions (SBEM) and in LBBEM packed at 10 (LBBEM,10) and 35 mN/m (LBBEM,35), which gave the following kinetic parameters: Vmax = 3.41 ± 0.15, 0.021 ± 0.002 and 0.030 ± 0.003 nmol.min-1·µg prot-1 and KM = 0.11 ± 0.02, 0.047 ± 0.017 and 0.026 ± 0.017 mM, respectively. Although from SBEM to LBBEM we lost active enzyme, the catalytic efficiency (Vmax/KM) increased ~750 times. Eugenol and 1,8-cineol inhibited BEA catalytic activity in LBBEM,35. Our results demonstrate the transmission of information between the membrane and the environment within the subphase immediately below the membrane, where anchored proteins are hosted. This was reflected by the membrane packing-induced modulation of BEA catalytic activity. Furthermore, LBBEM provides a proof of concept for the development of biosensors to screen new green pesticides acting through BEA interaction.