Ethanol Pretreatment Research Articles

Ethanol treatment enhances drought stress avoidance in cassava (Manihot esculenta Crantz).

External application of ethanol enhances tolerance to high salinity, drought, and heat stress in various plant species. However, the effects of ethanol application on increased drought tolerance in woody plants, such as the tropical crop "cassava," remain unknown. In the present study, we analyzed the morphological, physiological, and molecular responses of cassava plants subjected to ethanol pretreatment and subsequent drought stress treatment. Ethanol pretreatment induced a slight accumulation of abscisic acid (ABA) and stomatal closure, resulting in a reduced transpiration rate, higher water content in the leaves during drought stress treatment and the starch accumulation in leaves. Transcriptomic analysis revealed that ethanol pretreatment upregulated the expression of ABA signaling-related genes, such as PP2Cs and AITRs, andstress response and protein-folding-related genes, such as heat shock proteins (HSPs). In addition, the upregulation of drought-inducible genes during drought treatment was delayed in ethanol-pretreated plants compared with that in water-pretreated control plants. These results suggest that ethanol pretreatment induces stomatal closure through activation of the ABA signaling pathway, protein folding-related response by activating the HSP/chaperone network and the changes in sugar and starch metabolism, resulting in increased drought avoidance in plants.

Improving biogas production from different parts of spruce tree using leading pretreatments

Spruce is the most resistant type of lignocellulosic material to anaerobic digestion. Different parts of spruce tree, i.e., leaves, wood, branches, bark, fruit, and mixtures of these parts, were pretreated using the leading pretreatments, i.e., concentrated phosphoric acid, dilute sulfuric acid, and ethanolic organosolv pretreatment, to improve biogas production. The pretreatment effects on methane yield from both solid and liquid fractions of the pretreatments were evaluated. Different parts of the tree showed different behaviors. The maximum methane yields from the pretreated solids were obtained after phosphoric acid pretreatment, which yielded methane yields of 211.7 and 225.5 mL per g volatile solids (VS) of pretreated spruce leaves and mixture, respectively. The improvements were related to opened-up structure, crystallinity reduction, and delignification. Sulfuric acid pretreatment improved biomethane yield from liquids, but not solids. Moreover, organosolv pretreatment improved the yield from solids, but not wood, bark, and the mixture. The maximum methane production yield was 245.3 NmL CH4/gVS which was obtained from the organosolv liquor of spruce leaves. The highest overall methane production (252.9 L per Kg) was gained from the whole solid and liquid fractions from organosolv pretreatment of leaves. This methane yield corresponded to 2.4-fold improvement compared to that of the untreated leaves (107 NmL CH4/gVS). Thus, leaves and branches are less recalcitrant parts and do not need severe pretreatment, while bark and wood are the most recalcitrant parts and required severe pretreatment like concentrated phosphoric acid. Moreover, the mixture of all parts also required severe pretreatment for efficient biogas production.

Impact of pretreatments with ethanol and freezing on drying slice papaya: drying performance and kinetic of ultrasound-assisted extraction of phenolics compounds.

Pretreatments of drying can represent an alternative to minimize the negative aspect process on the dry samples. Thus, the influence of ethanol (ET) and freezing (FG) as drying pretreatments was analyzed for slices of papaya. The slices (5 mm) were submitted for drying kinetics (60 °C and 1.5m s-1 ). Drying kinetics experimental data were fitted using Page's model and a diffusive model with boundary condition of types I and III. Also the thermophysical properties (thermal conductivity and specific heat) were determined and finally, the kinetics of ultrasound-assisted (40 kHz and 132 W) extraction of total phenolic compounds (TPCs) were realized. The combined method (ET + FG) was more efficient in reducing the drying time of papaya slices (48%) and the model 2 simulating the boundary condition of the third type (type III) showed the best fit to the experimental data. Effective diffusivity and convective coefficient were higher for ET + FG, where the maximum reduction in water content was 91% compared to fresh slices. The pretreatments did not influence the thermal conductivity, however, they were significant in the specific heat and in the extraction of TPCs, being higher in the time of 180 min. It was confirmed in the results presented that the combined pretreatment ET + FG is the most viable for drying papaya slices. Furthermore, it was found to be the most efficient in minimizing the loss of TPCs. Therefore, this pretreatment has great potential for application in the development of high value-added foods. © 2022 Society of Chemical Industry.

Chemical and Morphological Structure of Transgenic Switchgrass Organosolv Lignin Extracted by Ethanol, Tetrahydrofuran, and γ-Valerolactone Pretreatments

The recalcitrance of lignocellulosic biomass is a challenge in biological-based biorefinery systems due to the complex physicochemical structure of plant cell walls. Pretreatment and genetic modification are two approaches in biomass conversion that have succeeded in modifying the structure of lignocellulose to enable better enzymatic deconstruction. However, the structural differences among pretreatment-solubilized lignin isolated from switchgrass genotypes have not been extensively investigated. Here, three organosolv pretreatment systems─ethanol (EtOH), tetrahydrofuran (THF), and γ-valerolactone (GVL)─were used on wild-type (WT) and two transgenic switchgrasses. All organosolv pretreatments caused a significant reduction in the molecular mass of lignins; particularly, up to ∼90% decrease was observed in EtOH-pretreated lignin compared to untreated lignin. The WT EtOH lignin also presented the smallest particle size among all WT lignins. THF pretreated transgenic lignins showed a higher molecular mass, β-O-4 linkages, and aliphatic hydroxyl content compared to EtOH and GVL pretreated lignin. The number of hydrogen bonds between lignin and the organic solvents calculated from the molecular dynamics simulations followed the same trend as the experimentally determined reduction in lignin molecular mass. The results revealed the structural changes of solubilized lignin isolated from wild-type and transgenic switchgrass after different organosolv pretreatments.

Ethanol induces heat tolerance in plants by stimulating unfolded protein response.

Ethanol priming induces heat stress tolerance by the stimulation of unfolded protein response. Global warming increases the risk of heat stress-related yield losses in agricultural crops. Chemical priming, using safe agents, that can flexibly activate adaptive regulatory responses to adverse conditions, is a complementary approach to genetic improvement for stress adaptation. In the present study, we demonstrated that pretreatment of Arabidopsis with a low concentration of ethanol enhances heat tolerance without suppressing plant growth. We also demonstrated that ethanol pretreatment improved leaf growth in lettuce (Lactuca sativa L.) plants grown in the field conditions under high temperatures. Transcriptome analysis revealed a set of genes that were up-regulated in ethanol-pretreated plants, relative to water-pretreated controls. Binding Protein 3 (BIP3), an endoplasmic reticulum (ER)-stress marker chaperone gene, was among the identified up-regulated genes. The expression levels of BIP3 were confirmed by RT-qPCR. Root-uptake of ethanol was metabolized to organic acids, nucleic acids, amines and other molecules, followed by an increase in putrescine content, which substantially promoted unfolded protein response (UPR) signaling and high-temperature acclimation. We also showed that inhibition of polyamine production and UPR signaling negated the heat stress tolerance induced by ethanol pretreatment. These findings collectively indicate that ethanol priming activates UPR signaling via putrescine accumulation, leading to enhanced heat stress tolerance. The information gained from this study will be useful for establishing ethanol-mediated chemical priming strategies that can be used to help maintain crop production under heat stress conditions.

Coproduction of hydrogen, butanol, butanediol, ethanol, and biogas from the organic fraction of municipal solid waste using bacterial cocultivation followed by anaerobic digestion

An integrated bioprocessing approach was applied to enhance energy recovery from the biodegradable fraction of municipal solid waste (BFMSW). Clostridium acetobutylicum and Enterobacter aerogenes with complementary characteristics were cocultivated for coproduction of hydrogen, 2,3-butanediol, and acetone-butanol-ethanol (ABE). Following the fermentation process, the remaining solids were used for biomethane production. The BFMSW was first subjected to ethanolic organosolv pretreatment and then enzymatic cellulose and hemicellulose hydrolysis at 5 and 8% solid loadings. The glucose (328 g/kg raw BFMSW), xylose (37.8 g/kg raw BFMSW), and starch (152.1 g/kg raw BFMSW) portions of the pretreated BFMSW hydrolysate with 5% solid loading were cofermented to hydrogen (162.8 L/kg raw BFMSW), 2,3-butanediol (42.5 g/kg raw BFMSW), butanol (121.9 g/kg raw BFMSW), ethanol (38.9 g/kg raw BFMSW), and acetone (45.2 g/kg raw BFMSW) by the coculture, and subsequently, the residual unfermented solids were further digested to biomethane (31.7 L/kg raw BFMSW). From the bioenergy perspective, 311.8 mL gasoline equivalent (10 MJ energy) was obtained from each kg of raw BFMSW, indicating the potential of the integrated fermentation-anaerobic digestion bioprocess for biofuels production from the zero-cost substrate.

Rewarding and Antidepressant Properties of Ketamine and Ethanol: Effects on the Brain-Derived Neurotrophic Factor and TrkB and p75NTR Receptors

There is a high level of comorbidity between depression and alcohol use disorder. Subanesthetic doses of ketamine induce short-acting and enduring antidepressant effects after a single or a few administrations. Considering such comorbidity, we assessed, in Swiss male mice, if ketamine-induced antidepressant-like effects would alter ethanol’s rewarding effects; and, if ethanol pretreatment would alter the rewarding and antidepressant effects of ketamine. The role of the brain-derived neurotrophic factor (BDNF) and its high and low affinity receptors TrkB and p75NTR, respectively, in both reward and depression-related behaviors is well established. The present study assessed, in outbred Swiss male mice, the expression of these proteins in the prefrontal cortex and hippocampus. Ketamine did not alter the development of ethanol-induced conditioned place preference (CPP), yet ethanol inhibited the expression of CPP induced by 50 mg/kg ketamine. The antidepressant action of 50 mg/kg ketamine was attenuated after repeated treatment (i.e., developed tolerance), an effect blocked by ethanol preexposure; ethanol also inhibited the antidepressant effect of 30 mg/kg ketamine. Ketamine (50 mg/kg) and Ethanol–Ketamine (50 mg/kg) groups showed lower levels of 145 kDa TrkB in the hippocampus than Saline-treated group. Ethanol–Ketamine (50 mg/kg) decreased the hippocampal expression of p75NTR compared to Saline–Saline and Saline–Ethanol groups. Ketamine (50 mg/kg) induced hippocampal downregulation of 145 kDa TrkB may contribute to ketamine-induced antidepressant tolerance. Likewise, a relationship between low hippocampal levels of p75NTR in the Ethanol–Ketamine (50 mg/kg) and ketamine-induced CPP blockade may be considered. The findings underscore potential ethanol–ketamine interactions likely to undermine ketamine putative antidepressant effects.

Foaming characteristics and impact of ethanol pretreatment in drying behavior and physical characteristics for avocado pulp powder obtained by foam mat drying.

The objective of this study was to optimize the production of powdered avocado using foam mat drying. In order to achieve this, the effect of Emustab® (4, 6, and 8% w/w), goat's milk (10, 15, and 20% w/w), and whipping time (15, 20, and 25min) on the foam physical properties of avocado pulp were evaluated. In addition, the influence of ethanol pretreatment on the drying kinetics, thermodynamic properties, and physicochemical characteristics of the powders was also assessed. An experimental design 23 with three central points was used in this study and optimized foam conditions were dried at 50, 60, and 70°C, with a fixed air speed of 1.5m/s. Empirical and diffusive models (boundary conditions of the third type) were adjusted to the experimental data to describe the drying kinetics and to determine the process activation energy and thermodynamic properties. The final products were characterized regarding their physical properties. Optimized foam mat drying conditions were achieved when avocado pulp was whipped for 15 min and 8% of Emustab® and 20% of powdered goat milk were used as foaming agents. The use of an ethanol pretreatment and higher drying temperature (70°C) resulted in higher drying rate (1.6×102 /min) and shorter processing time (270min). The ethanol pretreatment reduced the activation energy and Biot number and led to more uniform moisture distribution. The physical properties, such as water content, water activity, bulk, and tapped densities decreased with an increase in drying temperature and pretreatment with ethanol, whereas water absorption capacity increased. PRACTICAL APPLICATION: In this work, new information about the drying kinetics and mass transfer of the foam mat avocado pulp using ethanol as pretreatment is obtained. The results will contribute to the optimization production avocado foaming and powder. Ethanol pretreatment can represent an alternative to minimize the negative impacts on drying process and can be surely suggested as an industrial application.

Comparison of ultrasound and ethanol pretreatments before catalytic infrared drying on physicochemical properties, drying, and contamination of Chinese ginger (Zingiber officinale Roscoe)

This study aimed to investigate the effects of different pretreatment methods on the drying process and quality of catalytic infrared dried ginger slices, particularly the safety quality. Four different pretreatments strategies were used: sample submerged in distilled water, water + US pretreatment, ethanol pretreatment, and ethanol + US pretreatment. The results showed that all pretreatments reduced drying time, and sample pretreatment by ethanol + US had the highest drying efficiency, hardness, highest total phenolic content, and total flavonoid content retention. However, these pretreatments slightly decreased the rehydration ratio and gingerol content. The possible explanation for these results has been put forward by microstructure analysis. CIR-dried ginger samples were pretreated by four methods required by the agricultural standards of China. This study provides a new perspective on the commercial application of ethanol + US pretreatment for CIR-dried ginger slices.

A combination of deep eutectic solvent and ethanol pretreatment for synergistic delignification and enhanced enzymatic hydrolysis for biorefinary process

A novel pretreatment system containing deep eutectic solvents and ethanol (DES-E) for synergistic carbohydrate conversion and delignification was reported in this study. The DES-E pretreatment resulted in an enhanced glucose yield compared to individual DES and ethanol pretreatment for the three tested biomass, including Broussonetia papyrifera, corn stover and pine. To further explore the delignification mechanism, the solubilized lignin and residual lignin from Broussonetia papyrifera was recovered and extracted, then thoroughly characterized. The highest total OH content was found in the DES-E solubilized lignin, which could be used as antioxidant. The presence of ethanol in pretreatment liquor could protect the β-O-4 substructure from breakage and reduce lignin condensation, which favors the subsequent enzymatic hydrolysis. Comparable glucose yield and delignification performance was achieved by recycled DES. DES-E pretreatment offers a promising method for lignin isolation and cellulose digestibility improvement simultaneously.

Development and Optimization of a Surface Sterilization Protocol for the Tissue Culture of Pleurotus tuber-regium (Fr) Sing. and Auricularia auricula-judae

This study was carried out to develop and optimize a surface sterilization protocol for the sterilization of explants in the tissue culture of the edible mushrooms Pleurotus tuber-regium (Fr) Sing. and Auricularia auricula-judae. The explants were exposed to two sterilization agents; 70% ethanol (EtOH) and JIK® a locally produced bleaching solution containing 3.5% (w/v) sodium hypochlorite at concentrations of 2.5% (v/v) and 5.0% (v/v) with varying time intervals of one, two, five, ten and fifteen minutes. The results showed that treatment of explants with 5.0% (v/v) sodium hypochlorite solution for ten minutes preceded by 70% ethanol pre-treatment for two minutes gave the least explants contamination (0%) and highest explants survival (100%) for Pleurotus tuber-regium, while treatment of explants with 70% ethanol for one minute followed by 5.0% (v/v) sodium hypochlorite solution for five minutes, gave the highest survival rate (100%) and least explants contamination (0%) for Auricularia auricula-judae.

Poly-2-methyl-2-oxazoline–modified bioprosthetic heart valve leaflets have enhanced biocompatibility and resist structural degeneration

Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde-fixed heterograft tissue, such as bovine pericardium (BP), are widely used for treating heart valve disease, a group of disorders that affects millions. Structural valve degeneration (SVD) of BHV due to both calcification and the accumulation of advanced glycation end products (AGE) with associated serum proteins limits durability. We hypothesized that BP modified with poly-2-methyl-2-oxazoline (POZ) to inhibit protein entry would demonstrate reduced accumulation of AGE and serum proteins, mitigating SVD. In vitro studies of POZ-modified BP demonstrated reduced accumulation of serum albumin and AGE. BP-POZ invitro maintained collagen microarchitecture per two-photon microscopy despite AGE incubation, and in cell culture studies was associated with no change in tumor necrosis factor-α after exposure to AGE and activated macrophages. Comparing POZ and polyethylene glycol (PEG)-modified BP invitro, BP-POZ was minimally affected by oxidative conditions, whereas BP-PEG was susceptible to oxidative deterioration. In juvenile rat subdermal implants, BP-POZ demonstrated reduced AGE formation and serum albumin infiltration, while calcification was not inhibited. However, BP-POZ rat subdermal implants with ethanol pretreatment demonstrated inhibition of both AGE accumulation and calcification. Ex vivo laminar flow studies with human blood demonstrated BP-POZ enhanced thromboresistance with reduced white blood cell accumulation. We conclude that SVD associated with AGE and serum protein accumulation can be mitigated through POZ functionalization that both enhances biocompatibility and facilitates ethanol pretreatment inhibition of BP calcification.

Ethanol and blanching pretreatments change the moisture transfer and physicochemical properties of apple slices via microstructure and cell-wall polysaccharides nanostructure modification

The impacts of ethanol pretreatment and blanching on moisture transfer, microstructure, and nanostructure of cell-wall polysaccharides of apple slices were studied. The physicochemical properties, namely, color, rehydration, and antioxidant capacity were also evaluated. The results corroborated that the use of ethanol and blanching reduced drying time 45–60% and 21–42% at various drying temperatures (50, 60, 70, and 80 °C), respectively, compared to controls. Ethanol loosened the cell wall structure, thereby reducing the internal resistance of moisture diffusion, and the changes in cell wall structure caused by blanching were mainly due to the β-elimination degradation of pectins. Both samples of ethanol pretreatment and blanching possessed lower browning index and higher antioxidant capacity compared with the untreated ones. Overall, ethanol pretreated products exhibited the shortest drying time, less color change and higher antioxidant capacity. These results provide new insights on possible mechanisms about ethanol pretreatment and blanching to improve drying.

Uvaia fruit ( Eugenia pyriformis Cambess) drying: Ethanol as pre‐treatment, convective drying kinetics and bioactive compounds

This study evaluated the effects of ethanol pre-treatment on convective drying and its impacts on the bioactive compounds of uvaia. The treatments consisting of control and samples pre-treated by immersion in ethanol (99.8% v/v) for 10 and 20 min, followed by convective drying (1 m/s) at 40 and 60°C. The sample temperatures were traced over processing and the products were evaluated in relation to their content of phenolic compounds and antioxidant capacity. Pre-treatment times in combination with temperatures influenced drying time and were associated with ethanol penetration and volatility in the sample. Furthermore, the high vapor pressure of ethanol reduced the initial temperature of the samples. Drying temperatures and pre-treatments reduced by 16%–34% phenolics compounds and 13%–45% antioxidant capacity, which was associated with degradation and possible extraction by ethanol. The advantages of using ethanol were discussed, but also some limitations, especially on bioactive compounds. Practical applications Uvaia is a native fruit rich in sensory and healthy aspects. However, its high perishability and seasonality make it unfeasible for post-harvest commercialization. This work demonstrated that drying and application of ethanol proved to be effective for preserving this fruit, resulting in a shorter processing time. Although ethanol partially extracted the bioactive compounds, significant levels are still found in the final product—which can be used as convenient products with a positive impact on consumers' health. Furthermore, the proposed approach is simple, relatively cheap, and viable techniques to obtain stable products for both industry and small producers.

Effect of Gum Arabic and Ethanol Pretreatments on Drying Kinetics and Quality Attributes of Dried Carrot Slices

Effect of Gum Arabic and Ethanol Pretreatments on Drying Kinetics and Quality Attributes of Dried Carrot Slices

Synergistic integration of wastewaters from second generation ethanol plant for algal biofuel production: an industrially relevant option.

The present study provides an integrated method for utilizing the wastewaters from second generation (2G) ethanol pretreatment plant for microalgal biomass and lipid production. The study was conducted using a mixture of wastewaters (referred as MW; pH 4.3) generated after washing of acidic and alkaline-soaked lignocellulosic biomass prior to pretreatment process. The growth studies indicated that the thermotolerant strain of Chlorella pyrenoidosa (C. pyrenoidosa) M18 exhibited higher cell proliferation in wastewater as compared to freshwater. About 20-25% enhancement in biomass (509mg L-1 d-1 ± 3.09) and lipid productivity (146mg L-1 d-1 ± 1.34) was observed in MW. The total chlorophyll content and variable fluorescence by maximum fluorescence (Fv/Fm) ratio of strain cultivated in MW were 10.32µgmL-1 and 0.75, respectively. The use of MW also enhanced the content of saturated and monounsaturated fatty acids in total lipid. The exhausted wastewater medium obtained after harvesting the auto-flocculated biomass was also reused up to three successive growth cycles. The recycled medium without any nutrient addition could be used for two subsequent rounds with enhanced biomass (520mg L-1 d-1 ± 4.07) and lipid (157.71mg L-1 d-1 ± 1.09) productivities. This synergistic approach of cultivating thermotolerant microalgae with wastewater from 2G pretreatment plant provides an economical setup for development of commercial algal biofuel technology.

Protein Enrichment of Wheat Bread with Microalgae: Microchloropsis gaditana, Tetraselmis chui and Chlorella vulgaris.

Cell wall disrupted and dried Microchloropsis gaditana (Mg), Tetraselmis chui (Tc) and Chlorella vulgaris (Cv) microalgae biomasses, with or without ethanol pre-treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread protein by 30%. Baking performance, protein quality and basic sensory properties were assessed. Compared to wheat, Mg, Tc and Cv contain higher amounts of essential amino acids and their incorporation markedly improved protein quality in the bread (DIAAS 57–66 vs. 46%). The incorporation of microalgae reduced dough strength and bread volume and increased crumb firmness. This was most pronounced for Cv and Tc but could be improved by ethanol treatment. Mg gave adequate dough strength, bread volume and crumb structure without ethanol treatment. To obtain bread of acceptable smell, appearance, and colour, ethanol treatment was necessary also for Mg as it markedly reduced the unpleasant smell and intense colour of all algae breads. Ethanol treatment reduced the relative content of lysine, but no other essential amino acids. However, it also had a negative impact on in vitro protein digestibility. Our results show that Mg had the largest potential for protein fortification of bread, but further work is needed to optimize pre-processing and assess consumer acceptance.

Sustainable bioconversion of potato peel wastes into ethanol and biogas using organosolv pretreatment

Potato processing industries generate considerable amounts of residues, i.e., potato peel wastes (PPW). Valorization of PPW for bioethanol and biogas production via a biorefining process was investigated in this study. Organosolv pretreatment was performed on the PPW using 50–75% (v/v) ethanol solution at 120–180 °C with/without the presence of 1% (w/w) H2SO4 (as a catalyst). After the pretreatment, the solvent, i.e., ethanol, was recovered by distillation. Catalyzed organosolv pretreatment using 50% (v/v) ethanol at 120 °C followed by enzymatic hydrolysis resulted in a high hydrolysate yield of 539.8 g glucose/kg dry PPW that was successfully fermented to 224.2 g ethanol/kg dry PPW. To recover more energy, the liquid fraction of the pretreatment remained after solvent recovery and the unhydrolyzed solids that remained from the enzymatic hydrolysis were anaerobically digested. From each kg of dry PPW, the anaerobic digestion produced 57.9 L biomethane. Thus, the biorefinery comprising ethanolic organosolv pretreatment, solvent recovery, enzymatic hydrolysis, ethanolic fermentation, and anaerobic digestion of residues was produced 8112 kJ energy per kg of dry PPW.

Acute ethanol exposure stimulates microvesicle particle generation in keratinocytes

Ethanol has been demonstrated to exert profound effects upon cells and tissues via multiple mechanisms. One recently appreciated means by which cells can communicate with other cells is via the production and release of extracellular vesicles. Though smaller exosomes have been demonstrated to be released in response to ethanol exposure, the ability of ethanol to modulate the generation and release of larger microvesicle particles (MVP) is lesser studied. The present studies examined the ability of exogenous ethanol to generate MVP with a focus on skin cells. Acute ethanol exposure resulted in augmented MVP release in keratinocytes and in the skin and blood of mice. Unlike other stimuli such as ultraviolet B radiation or thermal burn injury, ethanol-mediated MVP release was independent of the Platelet-activating Factor receptor (PAFR). However, ethanol pretreatment was found to augment thermal burn injury-induced MVP in a PAFR-dependent manner. These studies provide a novel mechanism for ethanol-mediated effects, that could be relevant in the significant toxicity associated with thermal burn injury in the setting of alcohol intoxication.

Abstract 13818: Polyoxazoline Modification of Bovine Pericardial Bioprosthetic Heart Valve Leaflets Mitigates Protein-Glycation Associated Structural Degeneration

Introduction: Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde treated bovine pericardium (BP) are widely used to treat heart valve disease. BHV dysfunction from structural valve degeneration (SVD) develops over time, often necessitating device replacement. SVD is associated with both calcification and the accumulation of advanced glycation end products (AGE) and serum proteins within BHV leaflets. Here, we introduce a new strategy for mitigating AGE-associated SVD by modifying BP with a poly(2-methyl-2-oxazoline) (POZ). Hypothesis: Attached POZ will prevent BP deterioration by mitigating serum protein and pro-inflammatory AGE uptake. Methods: Covalently modified BP-POZ was studied for its effects on serum albumin and AGE entry in vitro via a mass-uptake assay and immunostaining. Resistance of BP-POZ to oxidation was assessed in comparison to poly(ethylene glycol) (PEG). Macrophage studies assessed the inflammatory properties of BP-POZ. A juvenile rat subdermal model was used to study serum protein and AGE uptake and calcification within BP-POZ, with or without ethanol pretreatment. A heart valve pulse duplicator was used to assess the protective effects of BP-POZ on BHV hydrodynamics following accelerated glycation. Results: POZ mitigated the accumulation of serum albumin and AGE in vitro . After exposure to AGE and macrophages, POZ preserved BP collagen structure while TNFα levels remained at baseline. Under oxidation conditions, POZ retained its protective function, unlike PEG. In the rat model, POZ reduced BP AGE (p<0.001) and albumin (p<0.001) uptake. Ethanol pretreatment of BP-POZ was effective at reducing both AGE and calcification. POZ mitigated the hydrodynamic dysfunction of BHV exposed to accelerated glycation conditions (p<0.001). Conclusions: SVD due to AGE and serum proteins can be effectively mitigated through POZ modification, that does not interfere with ethanol pretreatment mitigation of BP calcification.