Hydrophobic Resin Research Articles

Separation of recombinant erythropoietin and human serum albumin without the use of sophisticated equipment

A number of drugs based on recombinant erythropoietin contain human serum albumin as an auxiliary component. The presence of this protein hinders the proper control of the drug quality in accordance with the requirements of regulating agencies. We propose the novel method for separation of recombinant erythropoietin (epoetin beta) and human serum albumin. It is based on the subsequent use of hydrophobic sorbent and anion exchange resin placed in gravity flow columns (without the use of spin-columns). The proposed approach makes it possible to concentrate and purify the preparations containing the epoetin beta both at high and at minimal concentrations (the ratio of the amount of albumin and erythropoietin in the used preparations can reach 125:1). The average yield of epoetin beta after the use of hydrophobic sorbent and anion exchange resin was 75 % and 97 %, respectively. It was shown that the determined conditions of sample preparation had no affect on the content of the epoetin beta in the product.

Solvent-free synthesis of diacylglycerols via enzymatic glycerolysis between edible oils and glycerol catalyzed by self-made immobilized lipase PS@LXTE-1000

Diglycerol (DAG) is a structural lipid with the functions to lower body fat accumulation and decrease serum triglyceride level. However, the enzymatic synthesis of DAG is limited by the high-efficient and economic lipases. In this paper, the immobilized lipase PS@LXTE-1000 was self-made by immobilizing the Pseudomomas cepacian lipase on to the hydrophobic microporous resin LXTE-1000. The results indicate that LXTE-1000 was a uniform mesoporous sphere with the mean diameter of 400 ​μm, pore size of 14.6 ​nm, pore volume of 0.5 ​cm3/g and surface area of 126.0 ​m2/g, showing superior structural properties for lipase immobilization. Under the optimal reaction conditions with the molar ratio of rapeseed oil to glycerol being 1:1, adding amount of immobilized lipase being 4%, reaction at 50 ​°C, the highest DAG content of 46.7% was achieved in 3 ​h via enzymatic glycerolysis catalyzed by LXTE-1000. After 7 cycles of reuse, the self-made LXTE-1000 could still retain 78.3% of its initial catalytic ability. Besides, LXTE-1000 was observed to facilitate the DAG production via glycerolysis reaction between glycerol with other seven edible oils including corn oil, sesame oil, peony seed oil, rice bran oil, peanut oil, soybean oil and flaxseed oil. Specifically, the glycerolysis reaction with sesame oil, peony seed oil and rice bran oil even led to the DAG content of 52.1%, 53.3% and 51.2%, respectively, Hence, this paper provide a novel strategy to produce high-efficient and economic immobilized lipases, which shows great potential in the green synthesis of functional lipids such as DAG.

Resin bound gold nanocomposites assisted SE/ATR-FTIR spectroscopy for detection of pymetrozine insecticide in vegetable samples

The goal of this work was to assess the competence of organic hydrophobic resin bound gold nanocomposites (OH/R-AuNCs) for detection of pymetrozine insecticide from vegetable samples employing surface-enhanced/attenuated total reflectance-Fourier transform infrared (SE/ATR-FTIR) spectroscopy. The adsorption isotherm models, including the Langmuir, Freundlich and Temkin, are tested to reveal the interactive behaviour between the OH/R-AuNCs and pesticide. The adsorption occurs principally by London–Van der Waals dispersion interactions and hydrogen bonding interactions between the surface of OH/R-AuNCs materials and the hydrophobic part of pesticide molecule. The characteristic absorption band obtained at 3019.94 cm−1 was utilized for the quantitative analysis of pymetrozine insecticide in vegetable samples. The method was found to be accurate and precise, with mean recovery values in the range of 94.5–110 %, correlation coefficient of 0.992 %, and detection limit of 2.65 μg mL−1. The adsorption efficiency of the designed OH/R-AuNCs significantly influences the SE/ATR-FTIR response of the pymetrozine around 90 %. The optimized and validated method was applied to determine the residual concentrations of the pymetrozine that had been applied to vegetable samples.

In silico mediated workflow for rapid development of downstream processing: Orthogonal product-related impurity removal for a Fc-containing therapeutic

Therapeutic formats derived from the monoclonal antibody structure have been gaining significant traction in the biopharmaceutical market. Being structurally similar to mAbs, most Fc-containing therapeutics exhibit product-related impurities in the form of aggregates, charge variants, fragments, and glycoforms, which are inherently challenging to remove. In this work, we developed a workflow that employed rapid resin screening in conjunction with an in silico tool to identify and rank orthogonally selective processes for the removal of product-related impurities from a Fc-containing therapeutic product. Linear salt gradient screens were performed at various pH conditions on a set of ion-exchange, multimodal ion-exchange, and hydrophobic interaction resins. Select fractions from the screening experiments were analyzed by three different analytical techniques to characterize aggregates, charge variants, fragments, and glycoforms. The retention database generated by the resin screens and subsequent impurity characterization were then processed by an in silico tool that generated and ranked all possible two-step resin sequences for the removal of product-related impurities. A highly-ranked process was then evaluated and refined at the bench-scale to develop a completely flowthrough two-step polishing process which resulted in complete removal of the Man5 glycoform and aggregate impurities with a 73% overall yield. The successful implementation of the in silico mediated workflow suggests the possibility of a platformable workflow that could facilitate polishing process development for a wide variety of mAb-based therapeutics.

A Novel Kunitz Trypsin Inhibitor from Enterolobium gummiferum Seeds Exhibits Antibiofilm Properties against Pathogenic Yeasts.

Plant peptidase inhibitors play crucial roles in plant defence mechanisms and physiological processes. In this study, we isolated and characterised a Kunitz trypsin inhibitor from Enterolobium gummiferum seeds named EgPI (E. gummiferum peptidase inhibitor). The purification process involved two chromatography steps using size exclusion and hydrophobic resins, resulting in high purity and yield. EgPI appeared as a single band of ~20 kDa in SDS-PAGE. Under reducing conditions, the inhibitor exhibited two polypeptide chains, with 15 and 5 kDa. Functional characterisation revealed that EgPI displayed an inhibition stoichiometry of 1:1 against trypsin, with a dissociation constant of 8.4 × 10-9 mol·L-1. The amino-terminal sequencing of EgPI revealed the homology with Kunitz inhibitors. Circular dichroism analysis provided insights into the secondary structure of EgPI, which displayed the signature typical of Kunitz inhibitors. Stability studies demonstrated that EgPI maintained the secondary structure necessary to exhibit its inhibitory activity up to 70 °C and over a pH range from 2 to 8. Microbiological screening revealed that EgPI has antibiofilm properties against pathogenic yeasts at 1.125 μmol·L-1, and EgPI reduced C. albicans biofilm formation by 82.7%. The high affinity of EgPI for trypsin suggests potential applications in various fields. Furthermore, its antibiofilm properties recommended its usefulness in agriculture and antimicrobial therapy research, highlighting the practical implications of our research.

Comparative evaluation of the effect of 2% graphene oxide and 5% hydroxyapatite nanoparticles in isolation and in combination on micro tensile bond strength of 5th generation adhesive

Background Graphene is the thinnest, strongest, and stiffest imaginable material. The biocompatible property of graphene oxide can initiate and facilitate cell adhesion, proliferation, and differentiation of periodontal ligament, osteogenic, and oral epithelial cells. Furthermore, the antibiofilm and anti-adhesion properties of graphene oxide in the prevention of dental biofilm infections, dental caries, and dental erosion as well as for implant surface modification and as an anti-quorum sensing agent. Composites are the most often utilized materials for restoration in the field of dentistry due to adhesive resins' improved mechanical and cosmetic properties. To safeguard the dentin and prevent dental cavities, dentin adhesives are utilized to affix hydrophobic resin composites to hydrophilic dentin tissue. Materials and Method Dental adhesives have a harder time adhering to dentin because it contains more water and is less mineralized than enamel. This makes the method more sensitive. Result As a result, it was chosen to assess and contrast the impact of 5% Hydroxyapatite nanoparticles and 2% Graphene oxide nanoparticles, both separately and together, on the Micro tensile bond strength of 5th generation adhesive. Conclusion Graphene oxide is the most versatile form of Graphite in structural and functional configuration. Graphene oxide possesses extraordinary physical, chemical, optical, electrical and mechanical properties. Among the graphene family nanomaterials, the reduced form of Graphite adding the oxygenated functional group to the structure increases the surface area and therefore exhibits enviable excellent interaction ability with metal and ions as well as organic species. Graphene oxide in dentistry has provided outstanding results in antimicrobial action, regenerative dentistry, bone tissue engineering, drug delivery, physicochemical properties, enhancement of dental biomaterials and oral cancer treatment.

Chromatographic purification of the plasmin-like enzyme from clamworm (Perinereis aibuhitensis Grub) and its fibrinolytic activity by metal ions.

In this study, fibrinolytic protease was isolated and purified from Perinereis aibuhitensis Grub, and the extraction process was optimized. The properties of the enzyme, such as the amino acid composition, thermal stability, optimal temperature, and pH, were investigated. After detoxification, proteins collected from fresh Clamworm (Perinereis aibuhitensis Grub) were concentrated via ammonium sulfate precipitation. The crude protease was purified using gel filtration resin (Sephadex G-100), anion exchange resin (DEAE-Sepharose FF), and hydrophobic resin (Phenyl Sepharose 6FF). The molecular weight of the protease was determined by polyacrylamide gel electrophoresis (SDS-PAGE). The optimum temperature and optimum pH of the protease were determined. The activity of crude protease in the 40-60% salt-out section was the highest, reaching 467.53 U/mg. The optimal process for purifying crude protein involved the application of DEAE-Sepharose FF and Phenyl Sepharose 6FF, which resulted in the isolation of a single protease known as Asp60-D1-P1 with the highest fibrinolytic activity; additionally, the enzyme activity was measured at 3367.76 U/mg. Analysis by Native-PAGE and SDS-PAGE revealed that the molecular weight of Asp60-D1-P1 was 44.5 kDa, which consisted of two subunits with molecular weights of 6.5 and 37.8 kDa, respectively. The optimum temperature for Asp60-D1-P1 was 40°C, and the optimal pH was 8.0.

Nano-engineered hierarchical natural fibre composites with localised cellulose nanocrystals and tailored interphase for improved mechanical properties

Natural fibre composites have been utilised in many applications such as automotive and buildings, thanks to their high specific properties and environmentally friendly nature. However, the incompatibility between hydrophilic natural fibres and hydrophobic polymer resins remains a longstanding issue in natural fibre composites. Inspired by nature's hierarchical structures and tailored functionalities, a nano-engineered hierarchical natural fibre composite has been developed in this study, utilising cellulose nanocrystals (CNCs) as localised nano-reinforcements at flax surfaces in a flax/bio-epoxy system. A simple and versatile spray coating technique was used to deposit CNCs on unmodified flax fibres, without using any chemical solvents. With the increased surface roughness and hence improved epoxy wetting on nano-engineered flax surfaces (3 wt% CNC loading), mechanical properties of the hierarchical composites have been significantly improved, with a 60 % increase in interlaminar shear strength, indicating an enhanced interfacial load transfer between flax and epoxy, alongside improved flexural modulus (14 %) and strength (23 %). This green approach without using any chemicals provides a scalable and sustainable way to develop tailored interfaces for natural fibre composites with enhanced resin wetting and mechanical properties.

The Formation of D-Allulose 3-Epimerase Hybrid Nanoflowers and Co-Immobilization on Resins for Improved Enzyme Activity, Stability, and Processability.

As a low-calorie sugar, D-allulose is produced from D-fructose catalyzed by D-allulose 3-epimerase (DAE). Here, to improve the catalytic activity, stability, and processability of DAE, we reported a novel method by forming organic-inorganic hybrid nanoflowers (NF-DAEs) and co-immobilizing them on resins to form composites (Re-NF-DAEs). NF-DAEs were prepared by combining DAE with metal ions (Co2+, Cu2+, Zn2+, Ca2+, Ni2+, Fe2+, and Fe3+) in PBS buffer, and were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X-ray diffraction. All of the NF-DAEs showed higher catalytic activities than free DAE, and the NF-DAE with Ni2+ (NF-DAE-Ni) reached the highest relative activity of 218%. The NF-DAEs improved the thermal stability of DAE, and the longest half-life reached 228 min for NF-DAE-Co compared with 105 min for the free DAE at 55 °C. To further improve the recycling performance of the NF-DAEs in practical applications, we combined resins and NF-DAEs to form Re-NF-DAEs. Resins and NF-DAEs co-effected the performance of the composites, and ReA (LXTE-606 neutral hydrophobic epoxy-based polypropylene macroreticular resins)-based composites (ReA-NF-DAEs) exhibited outstanding relative activities, thermal stabilities, storage stabilities, and processabilities. The ReA-NF-DAEs were able to be reused to catalyze the conversion from D-fructose to D-allulose, and kept more than 60% of their activities after eight cycles.

Synergistic enhancement of hydrophobic dental adhesives: autonomous strengthening, polymerization kinetics, and hydrolytic resistance

The leading cause of composite restoration failure is recurrent marginal decay. The margin between the composite and tooth is initially sealed by a low-viscosity adhesive, but chemical, physical, and mechanical stresses work synergistically and simultaneously to degrade the adhesive, destroying the interfacial seal and providing an ideal environment for bacteria to proliferate. Our group has been developing self-strengthening adhesives with improved chemical and mechanical characteristics. This paper reports a self-strengthening adhesive formulation that resists hydrolysis-mediated degradation by providing intrinsic reinforcement of the polymer network through synergistic stimulation of free-radical polymerization, sol-gel reaction, and hydrophobicity. Hydrophobic resin formulation (NE1) was developed using HEMA/BisGMA 28/55w/w and 15 wt% MPS. Control (NC1) contained HEMA/BisGMA 28/55 w/w and 15 wt% MES. The polymerization kinetics, water sorption, leachates, and dynamic mechanical properties of the resin samples were investigated. The NC1 and NE1 samples showed comparable polymerization kinetics, degrees of conversion and water sorption. In contrast, NC1 showed significantly higher levels of HEMA and BisGMA leachate, indicating faster degradation in ethanol. At day 3, cumulative HEMA leachate for NC1 was ten times greater than NE1 (p < 0.05). Dynamic mechanical properties were measured at 37 and 70°C in both dry and wet conditions. Under dry conditions, the storage moduli of NC1 and NE1 were comparable and the glass transition temperature (Tg) of NC1 was statistically significantly lower (p < 0.001) than NE1. Under wet conditions, the storage modulus of NC1 was lower than NE1 and at 70°C there was a threefold difference in storage modulus. At this temperature and under wet conditions, the storage modulus of NC1 is statistically significantly lower (p < 0.001) than NE1. The results indicated that in the wet environment, NE1 provided lower chain mobility, higher crosslink density, and more hydrogen bonds. The newly formulated methacrylate-based adhesive capitalizes on free-radical polymerization, sol-gel reactions, and hydrophobicity to provide enhanced mechanical properties at elevated temperatures in wet environments and hydrolytic stability under aggressive aging conditions.

Degradable 4D-printed hydration-driven actuators from a single family of amphiphilic star-shaped copolymers

Actuators are largely used in biomedical applications in the presence of sensitive live cells or biomolecules, which makes actuators triggered by water uptake highly appealing. Dual-material printing and hydration driven expansion is a method of choice to produce such actuators, but mostly rely of non-degradable polymers or on the combination of polymers of different nature that may lead to interface incompatibilities. To overcome this challenge, we report here on two photocrosslinkable resins based on a single family of degradable hydrophilic or hydrophobic star-shaped poly(ethylene glycol)-poly(lactide) copolymers. The two materials are first printed individually and characterized to ensure that their properties enable the printing of dual material objects by stereolithographic digital-light processing. Dual-materials actuators are then printed by sequential switching of the hydrophobic and hydrophilic resin baths. Objects of simple and complex shapes are easily obtained and exhibit rapid actuation (<60 s) upon hydration. The swelling-induced shape changes are accurately reproduced by numerical modeling of the printed geometries using the obtained material swelling properties. This set of results offers new perspectives to develop 4D-printed temporary medical devices.

Organic-inorganic hybrid epoxy resin coating with high thermal stability and hydrophobicity for corrosion protection prepared by (3-aminopropyl) triethoxysilane as a bridging agent

The corrosion protection application of epoxy resin (EP) in high-temperature environments is greatly restricted due to thermal stability limit and inherent hydrophilicity. In this study, a hybrid epoxy resin was synthesized by grafting hexadecyltrimethoxysilane (HDTMS), 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane (PFDTMS), and tetraethyl orthosilicate (TEOS) onto the molecule of epoxy resin, using (3-aminopropyl) triethoxysilane (APTES) as a bridging agent. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses revealed the presence of C-N bonds and Si-O-Si bonds in the hybrid epoxy resin, confirming the success of the hybridization. Compared to pure epoxy resin, the hybrid epoxy resin coating effectively enhances the thermal stability while maintaining both corrosion resistance and hydrophobicity. Thermal gravimetric analysis (TGA) indicated that the initial decomposition temperature (T5%) of the hybrid epoxy resin coating increased from 327°C to 372°C. This enhancement is attributed to the introduction of Si-O-Si bonds and an increase in cross-linking density in the hybrid epoxy resin. Water contact angle measurements showed that with the introduction of C-F bonds and long carbon chains, the contact angle increased from 71° to 106°. The hydrophobic hybrid epoxy resin coating maintained a contact angle of 100° at 300°C for 300 hours. The transition from hydrophilicity to hydrophobicity improves the corrosion resistance of the coating.

Comparative evaluation of the effect of 2% graphene oxide and 5% hydroxyapatite nanoparticles in isolation and in combination on micro tensile bond strength of 5th generation adhesive

Background Graphene is the thinnest, strongest, and stiffest imaginable material. The biocompatible property of graphene oxide can initiate and facilitate cell adhesion, proliferation, and differentiation of periodontal ligament, osteogenic, and oral epithelial cells. Furthermore, the antibiofilm and anti-adhesion properties of graphene oxide in the prevention of dental biofilm infections, dental caries, and dental erosion as well as for implant surface modification and as an anti-quorum sensing agent. Composites are the most often utilized materials for restoration in the field of dentistry due to adhesive resins' improved mechanical and cosmetic properties. To safeguard the dentin and prevent dental cavities, dentin adhesives are utilized to affix hydrophobic resin composites to hydrophilic dentin tissue. Materials and Method Dental adhesives have a harder time adhering to dentin because it contains more water and is less mineralized than enamel. This makes the method more sensitive. Result As a result, it was chosen to assess and contrast the impact of 5% Hydroxyapatite nanoparticles and 2% Graphene oxide nanoparticles, both separately and together, on the Micro tensile bond strength of 5th generation adhesive. Conclusion Graphene oxide is the most versatile form of Graphite in structural and functional configuration. Graphene oxide possesses extraordinary physical, chemical, optical, electrical and mechanical properties. Among the graphene family nanomaterials, the reduced form of Graphite adding the oxygenated functional group to the structure increases the surface area and therefore exhibits enviable excellent interaction ability with metal and ions as well as organic species. Graphene oxide in dentistry has provided outstanding results in antimicrobial action, regenerative dentistry, bone tissue engineering, drug delivery, physicochemical properties, enhancement of dental biomaterials and oral cancer treatment.

Modeling the behavior of monoclonal antibodies on hydrophobic interaction chromatography resins

Monoclonal antibodies (mAbs) require a high level of purity for regulatory approval and safe administration. High-molecular weight (HMW) species are a common impurity associated with mAb therapies. Hydrophobic interaction chromatography (HIC) resins are often used to remove these HMW impurities. Determination of a suitable HIC resin can be a time and resource-intensive process. In this study, we modeled the chromatographic behavior of seven mAbs across 13 HIC resins using measurements of surface hydrophobicity, surface charge, and thermal stability for mAbs, and hydrophobicity and zeta-potential for HIC resins with high fit quality (adjusted R2 > 0.80). We identified zeta-potential as a novel key modeling parameter. When using these models to select a HIC resin for HMW clearance of a test mAb, we were able to achieve 60% HMW clearance and 89% recovery. These models can be used to expedite the downstream process development for mAbs in an industry setting.Graphical

Functionalized montmorillonite/epoxy resin nanocomposites with enhanced thermal and mechanical properties.

The poor interaction between the hydrophilic montmorillonite and hydrophobic epoxy resins leads to agglomeration of montmorillonite within epoxy resins, which finally results in poor macro properties of the epoxy resin nanocomposites. Although silane modification can improve the hydrophobicity of montmorillonite surface, the hydrolysis and condensation of silane lead to locking effect in the interlayer structure of functionalized montmorillonite. The effect of the functionalized montmorillonite on the properties of the epoxy resin remains unclear. Herein, we present multi technique approach to thoroughly evaluate the macro properties of the montmorillonite/epoxy resin nanocomposites, including dynamic mechanical thermal, thermo-mechanical, dielectric, water absorption and subsequently evaluate the molecular factors governing these characteristics. Importantly, the storage modulus has been enhanced by 44%, from 2416 MPa for pure epoxy resin to 2416 MPa for nanocomposites with 5.0 wt% functionalized montmorillonite. Our analysis reveals the increase of thermal stability and glass-transition temperature, as well as a reduction of the coefficient of thermal expansion with the addition of functionalized montmorillonite. Additionally, functionalized montmorillonite leads to decreased water absorption. This research aims to offer guidance for the development of high-performance montmorillonite/polymer nanocomposites, potentially opening up new applications for montmorillonite in polymer nanocomposites.

Fully biobased epoxy resins from ring opening polymerization of epoxidized pennycress (Thlaspi arvense L.) oil with itaconic and citric acids

Fully biobased thermosetting epoxy resins were efficiently synthesized from non-edible field pennycress (Thlaspi arvense L.) oil following a two-step sequence in which the oil was epoxidized by in situ-generated performic acid and then cured with citric and itaconic acids. Ring opening polymerization reactions were self-catalyzed, solvent-free, and conducted at 120 °C for 5 – 25 h. Analogous polymers were prepared from epoxidized soybean oil to serve as reference comparisons. The influence of comonomer combination and curing time on properties of the resulting elastomeric, ductile, thermally stable (DTG > 379 °C), hydrophobic (contact angle > 70 °) epoxy resins is reported. Crosslink density, storage modulus at the glass transition temperature (6.8 – 14.4 MPa), tensile strength (0.3 – 1.1 MPa), and gel content (87 – 96%) increased with cure time. Citrate-based polymers had higher crosslink densities (317 mol m−3) than itaconate-based polymers (164 – 279 mol m−3) due to the greater functionality of citric acid versus itaconic acid, which resulted in higher glass transitions (> 21 °C), tensile strengths (> 0.6 MPa), and storage moduli in the rubbery state (> 2.6 MPa). Finally, the lower oxirane content of EPO versus ESO resulted in lower crosslink density, storage modulus, tensile strength, and elongation at break. Overall, the epoxy networks had promising thermal, mechanical, and viscoelastic properties that were tunable by selection of appropriate comonomer combinations and curing times.

Comparative evaluation of the effect of 2% graphene oxide and 5% hydroxyapatite nanoparticles in isolation and in combination on micro tensile bond strength of 5th generation adhesive

Graphene is the thinnest, strongest, and stiffest imaginable material. The biocompatible property of graphene oxide can initiate and facilitate cell adhesion, proliferation, and differentiation of periodontal ligament, osteogenic, and oral epithelial cells. Furthermore, the antibiofilm and anti-adhesion properties of graphene oxide in the prevention of dental biofilm infections, dental caries, and dental erosion as well as for implant surface modification and as an anti-quorum sensing agent. Composites are the most often utilized materials for restoration in the field of dentistry due to adhesive resins' improved mechanical and cosmetic properties. To safeguard the dentin and prevent dental cavities, dentin adhesives are utilized to affix hydrophobic resin composites to hydrophilic dentin tissue. Dental adhesives have a harder time adhering to dentin because it contains more water and is less mineralized than enamel. This makes the method more sensitive. As a result, it was chosen to assess and contrast the impact of 5% Hydroxyapatite nanoparticles and 2% Graphene oxide nanoparticles, both separately and together, on the Micro tensile bond strength of 5th generation adhesive. Graphene oxide is the most versatile form of Graphite in structural and functional configuration. Graphene oxide possesses extraordinary physical, chemical, optical, electrical and mechanical properties. Among the graphene family nanomaterials, the reduced form of Graphite adding the oxygenated functional group to the structure increases the surface area and therefore exhibits enviable excellent interaction ability with metal and ions as well as organic species. Graphene oxide in dentistry has provided outstanding results in antimicrobial action, regenerative dentistry, bone tissue engineering, drug delivery, physicochemical properties, enhancement of dental biomaterials and oral cancer treatment.

Graft copolymer of tannin and polyvinyl alcohol with acrylic acid for the preparation of hydrophobic biodegradable film

Using CaCl2-H2O2 as the initiator, hydrophobic tannin-acrylic resin (TA) was prepared by grafting acrylic monomers onto tannins through redox reaction. Subsequently, biodegradable TA-polyvinyl alcohol (PVOH) hydrophobic film (TAP) was prepared by blending TA with PVOH at room temperature. The results of Fourier transform infrared spectroscopy (FT-IR) and Electro Spray Ionization Mass Spectroscopy (ESI-MS) showed that polypropylene undergoes graft copolymerization at position 8 of the A-ring in tannin and acrylic monomers. The results of Gel Permeation Chromatography (GPC) showed that the blending of TA resin with PVOH resulted in a higher molecular weight and denser network structure of the film. The preparation process of TAP film is simple, with room temperature curing and no surface pores and cracks. Moreover, the addition of TA transforms hydrophilic PVOH films into hydrophobic films, with a water contact angle of up to 110°. At the same time, TAP films have higher Brinell hardness and elongation at break compared to PVOH film. In addition, thermogravimetric analyzer (TG) and ultraviolet visible light (UV–Vis) measurements showed that the TAP film has good thermal stability and excellent resistance to UV–Vis. More importantly, the TAP film was found to have good biodegradability against Penicillium sp. Scanning electron microscopy (SEM) observed that the TAP film was degraded by Penicillium sp. after 15-days exposure.

Biological production of epicoccamide-aglycone and its cytotoxicity

Epicoccamide (EPC) is an O-d-mannosylated acyltetramic acid of Epicoccum origin and is a bolaamphiphilic fungal polyketide. EPC displays weak toxicity against Staphylococcus aureus and HeLa cell lines. The EPC biosynthetic gene cluster was previously identified in Epicoccum nigrum and knockout of the glycosyltransferase gene (epcB) abolished EPC production. EPC-aglycone was expected in the epcB knockout but was not found. This study demonstrates that extractive culture using the hydrophobic resin Diaion HP-20 resulted in the production of EPC-aglycone, which was isolated using chromatographic separation techniques, and its structural identity was substantiated by chemical analyses. EPC-aglycone displayed strong antibacterial activity against Staphylococcus aureus, with the minimal inhibitory concentration of 1 μg/mL (64 μg/mL for EPC). EPC-aglycone displayed higher levels of growth inhibition against HeLa cell line (the half inhibitory concentration, 19 μM) and WI-38 (15 μM) cell line than EPC (76 μM and 38 μM vs. HeLa and WI-38, respectively). The dose–response curve fit of growth inhibition indicated that EPC-aglycone adopted a shallow curve (low slope factor), which was different from that of EPC, suggesting that their cellular targets are distinct from each other. This study substantiates that the d-mannose attachment is the final step in EPC biosynthesis, showcasing a glycosylation-mediated modulation of the biological activity of simple acyltetramic acid. This study also highlights the usefulness of extractive cultures in mining cryptic microbial natural products.

Enhanced ethanol production using hydrophobic resin detoxified Pine forest litter hydrolysate and integrated fermentation process development supplementing molasses.

Globally escalating ethanol demand necessitates the use of hybrid technologies integrating first- and second-generation biofuel feedstocks for achieving the futuristic targets of gasoline replacement with bioethanol. In present study, an optimized two-step sequential pre-treatment (first dilute alkali, then dilute acid) of Pine forest litter (PFL) was developed. Furthermore, the saccharification of pre-treated PFL was optimized through Response Surface Methodology using Box-Behnken Design, wherein 0.558g/g of reducing sugar was released under the optimized conditions (12.5% w/v of biomass loading, 10 FPU/g of PFL enzyme loading, 0.15% v/v Tween-80 and 48h incubation time). Moreover, during hydrolysate fermentation using Saccharomyces cerevisiae NCIM 3288 strain, 22.51 ± 1.02g/L ethanol was produced. Remarkably, hydrophobic resin (XAD-4) treatment of PFL hydrolysate, significantly removed inhibitors (Furfural, 5-hydroxymethylfurfural and phenolics) and increased ethanol production to 27.38 ± 1.18g/L. Furthermore, during fermentation of molasses supplemented PFL hydrolysate (total initial sugar: 100 ± 3.27g/L), a maximum of 46.02 ± 2.08g/L ethanol was produced with 0.482g/g yield and 1.92g/l/h productivity. These findings indicated that the integration of molasses to lignocellulosic hydrolysate, would be a promising hybrid technology for industrial ethanol production within existing bio-refinery infrastructure.