Ethylcarbodiimide Hydrochloride Research Articles

Direct amidation of acids in a screw reactor for the continuous flow synthesis of amides.

A simple and efficient solvent-free protocol for continuous flow synthesis of amides at room temperature is developed using easily available starting materials. N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC.HCl) was used as the reagent for the formation of an amide bond without using any metal catalyst or additives. A jacketed screw reactor when operated over a residence time of 30 300 s helped achieve almost complete conversion. This approach is extended for the synthesis of 36 derivatives and 2 bioactive molecules using different substrates having different aliphatic mono and di-acids as well as aromatic acids, including aromatic hetero-acid compounds and phenyl hydrazine. The target amide was scaled up to 100 g with an average 90% yield.

Electrochemical Biosensor for the Determination of Specific Antibodies against SARS-CoV-2 Spike Protein

In this article, we report the development of an electrochemical biosensor for the determination of the SARS-CoV-2 spike protein (rS). A gold disc electrode was electrochemically modified to form the nanocrystalline gold structure on the surface. Then, it was further altered by a self-assembling monolayer based on a mixture of two alkane thiols: 11-mercaptoundecanoic acid (11-MUA) and 6-mercapto-1-hexanol (6-MCOH) (SAMmix). After activating carboxyl groups using a N-(3-dimethylaminopropyl)-N'-ethyl-carbodiimide hydrochloride and N-hydroxysuccinimide mixture, the rS protein was covalently immobilized on the top of the SAMmix. This electrode was used to design an electrochemical sensor suitable for determining antibodies against the SARS-CoV-2 rS protein (anti-rS). We assessed the association between the immobilized rS protein and the anti-rS antibody present in the blood serum of a SARS-CoV-2 infected person using three electrochemical methods: cyclic voltammetry, differential pulse voltammetry, and potential pulsed amperometry. The results demonstrated that differential pulse voltammetry and potential pulsed amperometry measurements displayed similar sensitivity. In contrast, the measurements performed by cyclic voltammetry suggest that this method is the most sensitive out of the three methods applied in this research.

Salivary esterases dramatically reduce biostability of dentin collagen treated with galloylated polyphenols.

To investigate the effects of salivary esterases on biostability of collagen treated by galloylated polyphenols. Human dentin was microtomed into 6-μm-thick films, which were demineralized and treated for 60s using solutions containing 0.6% and 2% of one of the crosslinkers: tannic acid (TAC), epigallocatechin gallate (EGCG), epigallocatechin (EGC), and N-[3-dimethylaminopropyl]-N'-ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS), and for 1h using EDC/NHS. Half of the treated and untreated (control) films were subjected to human saliva incubation. Collagen biostability was assessed via exogenous protease biodegradation by weight loss and hydroxyproline release, and endogenous MMPs by in situ zymography. The degradation products of galloylated polyphenols (TAC and EGCG) by saliva were monitored using proton nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The esterase activity of saliva induced by the crosslinkers was also assessed. Collagen films treated with TAC and EGCG exhibited significantly improved biostability (p<0.05); however, the enhanced biostability was severely reduced after saliva incubation (p<0.001). For EDC/NHS treated collagen, saliva incubation showed negligible effect on the biostability. 1H NMR studies confirmed the esterase-catalyzed hydrolysis of the galloyl. GPC measurements showed decreased molecular weight of TAC in saliva indicating its chemical degradation. Both TAC and EGCG showed much higher esterase activity than other treatment groups. The galloyl group plays important role in collagen crosslinking, inducing higher biostability. However, galloylated polyphenols crosslinked on collagen are highly susceptible to metabolism of human saliva by salivary esterase, dramatically compromising the enhanced biostability.

Interaction of haemin with albumin-based macroporous cryogel: Adsorption isotherm and fluorescence quenching studies.

Albumin-based cryogels for capturing haemin were synthesised by crosslinking different biomolecules, bovine serum albumin (BSA) and ovalbumin (OVA). The impact of the protein and coupling agent concentrations on cryogel's mechanical properties, swelling ratios and polymerisation yields, as well as autoclaving as a post-treatment on the cryogel, were studied. We found that BSA (50mg/ml) and the crosslinker (N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, 46mg/ml) formed a cryogel with optimum physical characteristics at a comparatively low protein concentration. The cryogel's mechanical stability was increased using a double-layer cryogel approach by crosslinking the BSA proteins at subzero temperature inside an acrylamide and hydroxyethyl methacrylate premade cryogels. Batch binding and kinetic adsorption isotherms of haemin on the cryogels were assessed to evaluate their binding capacity toward the porphyrin molecule. The results showed that single-layer cryogels (BSA and OVA) had a higher capacity (∼0.68mg/ml gel) and higher reaction rate constant towards haemin adsorption than double-layer gels. In contrast, the double-layer cryogels had higher mechanical strength than single-layer gels. The experimental results suggested that the cryogels followed the Freundlich model and the pseudo-second-order isotherm for batch adsorption and kinetics, respectively. The interaction between haemin and the gels was studied by fluorescence quenching. We found between 1.1 and 1.6 binding sites for different cryogels.

Cross-linked iron nanoparticle-doped reduced graphene oxide membranes for micropollutant removal from water

Emerging contaminants in potable waters and wastewaters are a global concern exacerbated by industrial growth. Graphene-based nanomaterials (e.g., rGO) incorporated at a membrane’s surface have been shown to enhance separation performance by increasing adsorption and altering membrane pore size. However, rGO surface-deposited membranes demonstrate low water fluxes and poor stability due to high rGO interlayer packing density and nanosheet swelling. Herein, a cationic polyelectrolyte cross-linked rGO nanocomposite membrane was developed to address these issues. These membranes were formed by a layer of iron doped rGO (rGO–Fe) cross-linked with hyperbranched polyethylenimine (HPEI) vacuum-deposited onto a polydopamine (PDA) coated polyethersulfone (PES) ultrafiltration membrane. The HPEI cross-linking of iron-doped rGO was accomplished by 1) activating the carbonyl groups of the iron nanoparticle-decorated graphene oxide (GO–Fe) by N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC hydrochloride) and N-Hydroxysuccinimide (NHS), 2) cross-linking GO–Fe through the primary amines of HPEI, and 3) chemical reduction of cross-linked GO–Fe by NaBH4. The resulting rGO nanocomposite membrane was moderately stable in aqueous solution for over 20 days. The optimized membrane achieved a water permeance of 39.8 L·m−2·hr−1·bar−1, which was comparable or higher than most reported graphene-based membranes. In addition to adsorption and size exclusion, pH-dependent electrostatic interactions were identified to control charged solute separation, resulting in removals >75.8%, 81.6% and 95.7% respectively for p-nitrophenol (PNP, 6.5 mg/L), methylene blue (MB, 20 mg/L) and methyl orange (MO, 20 mg/L) during dead-end ultrafiltration. This study provides a promising material framework for rGO nanocomposite membranes useful for low-pressure micropollutant removal.

Modification of silica particles with poly(phenylboronic acid) brushes for fabricating hollow mesoporous carbon nanospheres

AbstractPorous carbon nanospheres have attracted extensive attention due to their excellent advantages in specific surface area, pore distribution, and electronic conductivity. Herein, boron‐doped hollow carbon nanospheres with mesoporous walls have been successfully synthesized via a combination of hard/soft templating and boronic acid/sugar ligation. Surface‐initiated Cu(0) mediated reversible deactivation radical polymerization was used to initiate the polymerization of 2‐hydroxyethyl acrylate and poly(ethylene glycol) methyl ether acrylate from the surface of silica. 4‐carboxy‐3‐fluorophenylboronic acid was introduced as a boron precursor by N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide hydrochloride coupling and fructose was introduced as a carbon precursor by boronic esters. After carbonization and template etching, boron‐doped porous carbon spheres could be obtained. We believe such in‐situ heteroatom‐doped method has great potential in preparing hollow mesoporous carbon nanospheres with excellent properties.

Flexible Multifunctional Self-Expanding Electrospun Polyacrylic Acid Covalently Cross-Linked Polyamide 66 Nanocomposite Fiber Membrane with Excellent Oil/Water Separation and High pH Stability Performances

In this paper, we report for the first time the successful formation of a covalent cross-linking structure between polyacrylic acid and polyamide 66 in an electrospun nanofiber membrane by the facilitated amidation reaction using N-Hydroxy-succinimide (NHS) and N-(3-Dimethylaminopropyl)-N’-ethyl-carbodiimide hydrochloride (EDC). The structure and properties of the fiber membrane are characterized using scanning electron microscopy, wide field X-ray diffraction and differential scanning calorimetry. The results show that the presence of the cross-linked structure not only affects the construction of the nanofiber network framework but also influences the pore size distribution and size of the fiber membrane surface, which in turn affects its retention of contaminants and water absorption performance. After modification, the cross-linked membranes exhibited a significant retention performance of up to 77% for methyl tert-butyl ether (MTBE) with a reduced pure water flux. Furthermore, after crosslinking, the fiber membrane has been strongly enhanced with more stable pH response behavior.

Synthesis and characterization of gelatin/lignin hydrogels as quick release drug carriers for Ribavirin

In this study, hydrogels based on gelatin and lignin were fabricated as efficient drug carriers for Ribavirin. The obtained hydrogels were characterized by scanning electron microscopy (SEM), ATR-FTIR spectroscopy, differential scanning calorimetry (DSC), mechanical compression and rheometry. Results showed that the pore structure, viscoelastic behavior and swelling ability significantly influenced by varying lignin content and crosslinker ratio. By increasing the crosslinker N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) content, the pore size became smaller, while increasing the lignin content resulted in larger pores. In addition, all hydrogels show strong shear thinning behavior. Ribavirin was used as a drug model, and its release rate was enhanced by increasing lignin content in the binary hydrogel structure. A higher Ribavirin cumulative release was observed for gelatin/lignin with higher lignin content (3 %) hydrogel. These findings emphasize the chemical composition on the structure and the release behavior of lignin-containing hydrogels.

Conjugation of Ctx(Ile21)-Ha Antimicrobial Peptides to Chitosan Ultrathin Films by N-Acetylcysteine Improves Peptide Physicochemical Properties and Enhances Biological Activity

The importance of obtaining new compounds with improved antimicrobial activity is a current trend and challenge. Some polymers such as chitosan have shown promising bactericidal properties when they are structurally modified, which is due to the binding versatility provided by their free amines. Likewise, antimicrobial peptides (AMPs) have received attention in recent years because of their bactericidal activity that is similar to or even better than that of conventional drugs, and they exhibit a low induction rate of antimicrobial resistance. Herein, the modified AMP Ctx(Ile21)-Ha-Ahx-Cys was conjugated to chitosan using N-acetylcysteine as an intermediate by the carbodiimide method. Films were prepared using protonated chitosan in 1% acetic acid and Ctx(Ile21)-Ha-Ahx-Cys AMP dissolved in N-acetylcysteine-chitosan; 1.6 mmol of ethylcarbodiimide hydrochloride, 1.2 mmol of N-hydroxysulfosucchimide, and 0.1 mol L –1of N-morpholino)ethanesulfonic acid buffer at pH 6.5 by continuous stirring at 100 × g for 10 min at 37 °C. Physicochemical properties were evaluated by Fourier-transform infrared spectroscopy, differential scanning calorimetry/thermogravimetric analysis, and X-ray diffraction to determine the mechanical properties, solubility, morphology, and thickness. Furthermore, the antimicrobial activities of chitosan-based conjugated films were evaluated againstStaphylococcus aureus,Pseudomonas aeruginosa,SalmonellaTyphimurium, andEscherichia coli. The results showed that the conjugation of a potent AMP could further increase its antibacterial activity and maintain its stable physicochemical properties. Therefore, the developed peptide–chitosan conjugate could be applied as an additive in surgical procedures to prevent and combat bacterial infection.

Wet Electrospun Nanofibers-Fortified Gelatin/Alginate-Based Nanocomposite as a Single-Dose Biomimicking Skin Substitute

We report the development and evaluation of a series of well-designed single-dose extracellular matrix (ECM)-mimicking nanofibers (NFs)-reinforced hydrogel (HG)-based skin substitute for wound healing. The HG matrix of the proposed skin substitute is composed of gelatin (GE) and sodium alginate (SA), and incorporates hyaluronic acid (HA) as a key component of the natural ECM, as well as the antimicrobial Punica granatum extract (PE). This HG nanocomposite was cross-linked by the biocompatible N-(3-(dimethylamino)propyl)-N'-ethylcarbodiimide hydrochloride (EDC) cross-linker, and was reinforced with fragmented trans-ferulic acid (FA)-loaded cellulose acetate/polycaprolactone (PCL/CA) NFs. The NFs were obtained via wet electrospinning into a poly(vinyl alcohol) (PVA) coagulating solution to closely resemble the porous structure of the ECM fibers, which facilitates cell migration, attachment, and proliferation. The proposed design of the skin substitute allows adjustable mechanical characteristics and outstanding physical properties (swelling and biodegradability), as well as an excellent porous microstructure. The developed skin substitutes were characterized using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and electron microscopy. In addition, the biodegradability, biocompatibility, bioactivity, mechanical, and in vitro drug release characteristics were investigated. Moreover, an in vivo excisional full-thickness defect model was conducted to assess skin regeneration and healing effectiveness. The average diameters of the plain and FA-loaded NFs are 210 ± 12 nm and 452 ± 25 nm, respectively. The developed ECM-mimicking skin substitutes demonstrated good antibacterial activity, free-radical scavenging activity, cytocompatibility, porosity, water absorption ability, and good biodegradability. In vivo application of the ECM-mimicking skin substitutes revealed their excellent wound-healing activity and their suitability for single-dose treatment of deep wounds with reducing the wound diameter to 0.95 mm after 15 days of treatment. Moreover, the histological investigation of the wound area demonstrated that the applied skin substitutes have not only enhanced the wound healing progress, but also can participate in improving the quality of the regenerated skin in the treated area via facilitating collagen fibers regeneration and deposition.

Synthesis of smart carriers based on tryptophan-functionalized magnetic nanoparticles and its application in 5-fluorouracil delivery

Multifunctional nanocarriers, specifically for tumor targeting and traceable features, have been increasingly considered in cancer therapies. Herein, a novel targeting agent (TA), tryptophan (TRP), was proposed for the synthesis of functionalized (3-aminopropyl) triethoxysilane-iron oxide nanoparticles using two methods, creating a smart drug delivery system (DDS). In one method, two-step, glutaraldehyde (GA) as a linker, bonded TRP and amino-functionalized magnetite, and in the second method, one step, TRP binding was carried out by (3-dimethyl aminopropyl)-N’-ethyl carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide ester. The synthesis yield of the second method was 7% higher than the first method. After synthesizing DDS, 5-fluorouracil (5-FU) was loaded on nanocarriers and was observed TRP functionalized nanoparticles by GA have better loading efficiency, which was 50% greater than the product from the one-step method. A pH-sensitive release profile was also studied for 5-FU/DDS with the release of almost 75% and 50% at pH 5.5 and 7.4, respectively. To analyze the biological aspects of nanocarriers, human breast cancer, MCF-7, and embryonic kidney, HEK293, cell lines were used for cellular uptake and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays. In vitro studies confirmed that TRP can act as a TA as its cellular uptake through cancerous cells was 40% greater than normal cells, and the MTT assay confirmed that using DDS can increase and decrease the cell viability of normal cells and cancerous cells, respectively, compared to free drug. Therefore, it was concluded that advanced nano-assembly is a great candidate for breast cancer cell-targeted delivery.

Enhancement of immune responses using ovalbumin-conjugated Eucommia ulmoides leaf polysaccharides encapsulated in a cubic liquid-crystalline phase delivery system.

To improve the adjuvant activity of polysaccharides from Eucommia ulmoides leaves (PsEUL) in inducing an effective immune response against ovalbumin (OVA), PsEUL were conjugated to OVA using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) method. The synthesized PsEUL-OVA was encapsulated using phytantriol and F127 to produce PsEUL-OVA cubosomes (Cubs), a novel delivery system. The physicochemical properties and immune modulation effects of this novel delivery system were explored. In vitro, PsEUL-OVA/Cubs carrying large amounts of OVA were rapidly phagocytized by macrophages and upregulated macrophage proliferation, thereby stimulating cytokine production (interleukin (IL)-6 and IL-4). In vivo, PsEUL-OVA/Cubs increased the titer of OVA-specific antibodies (immunoglobulin (Ig)G, IgG2b, IgG2a and IgG1) and cytokine levels (IL-2, IL-6, IL-4 and interferon-γ). In addition, the cubosomes promoted the differentiation of CD8+ and CD4+ T cells in the spleen and the maturation of dendritic cells (DCs). These results indicated that PsEUL-OVA/Cubs stimulated both cellular and humoral immune responses by enhancing the phagocytic activity of DCs and macrophages and increasing the antigen presentation efficiency. Collectively, the findings demonstrate that PsEUL-antigen/Cubs can be a useful delivery vehicle with immune response-promoting effects. Therefore, this study lays the foundation for the development of novel adjuvant-antigen delivery systems with potential applications in vaccine design. © 2022 Society of Chemical Industry.

Preparation of IgY Oriented Conjugated Fe3O4 MNPs as Immunomagnetic Nanoprobe for Increasing Enrichment Efficiency of Staphylococcus aureus Based on Adjusting the pH of the Solution System.

Immunomagnetic separation based on Fe3O4 magnetic nanoparticles (MNPs) has been widely performed in sample pretreatment. The oriented conjugation strategy can achieve a better capture effect than the N-(3-dimethylamlnopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) /N-hydroxysuccinimide (NHS) method. However, immunoglobulin yolk (IgY) cannot be oriented through an SPA strategy like immunoglobulin G (IgG). In this article, an oriented conjugation nanoprobe was prepared for the enrichment of bacteria based on pH adjusting. The main factors affecting the enrichment efficiency were studied, such as the pH of the buffer system, the concentration of IgY, the concentration of nanoprobe, and the enrichment time. Under the optimal conditions, the enrichment efficiency toward target bacteria could reach 92.8%. Combined with PCR, the limit of detection (LOD) was found to be 103 CFU/ml, which was lower than the PCR only. In conclusion, we provided a new protocol for the oriented conjugation of IgY and high sensitivity detection with simple pretreatment.

Effect of crosslinking, hydroxyapatite addition, and fiber alignment to stimulate human mesenchymal stem cells osteoinduction in polycaprolactone‐based electrospun scaffolds

AbstractElectrospinning is a versatile technique for producing composite scaffolds with nanostructure properties similar to the natural extracellular matrix. Biomaterials possessing mechanical, structural, and biological properties required for bone tissue engineering are a big challenge. However, the effect of fiber alignment, their mechanical properties, and chemical modifications on fibers are usually investigated individually. In this study, PCL/GE/HA scaffolds were electrospun in a static and drum rotatory collector to investigate the effects of alignment on the physicochemical properties of composite scaffolds. Furthermore, to achieve a stable composite with natural polymer gelatin (GE), a water‐soluble, zero‐length crosslinker (N‐[3‐dimethylaminopropyl]‐N′‐ethylcarbodiimide hydrochloride, EDC) was used to crosslink GE. Our results have outlined that the incorporation of GE, as well as crosslinking process, produced a hydrophilic biomaterial, improving wettability compared to pure polycaprolactone (PCL). In addition, the alignment reinforced the material, increasing mechanical strength. Biological tests showed that GE addition and the alignment allowed a better osteoinduction than pure random PCL.

Surface Plasmon Resonance Immunosensor with Antibody-Functionalized Magnetoplasmonic Nanoparticles for Ultrasensitive Quantification of the CD5 Biomarker

A surface plasmon resonance (SPR) immunosensor signal amplification strategy based on antibody-functionalized gold-coated magnetic nanoparticles (mAuNPs) was developed for ultrasensitive and quantitative detection of the CD5 biomarker using an indirect sandwich immunoassay format. The gold surface of the SPR sensor disk and mAuNPs was modified with a self-assembled monolayer of 11-mercaptoundecanoic acid (11-MUA), and the coupling method using N-(3-(dimethylamino)propyl)-N′-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide was used to immobilize capture antibodies against human CD5 (anti-CD52A) and detection antibodies against human CD5 (anti-CD52B), respectively. The mAuNPs and anti-CD52B conjugates (mAuNPs–anti-CD52B) were separated by an external magnetic field and used to amplify the SPR signal after the formation of the anti-CD52A/CD5 immune complex on the SPR sensor disk. Compared to the direct CD5 detection with a limit of detection (LOD) of 1.04 nM and a limit of quantification (LOQ) of 3.47 nM, the proposed sandwich immunoassay utilizing mAuNPs–anti-CD52B significantly improved the LOD up to 8.31 fM and the LOQ up to 27.70 fM. In addition, it showed satisfactory performance in human blood serum (recovery of 1.04 pM CD5 was 109.62%). These results suggest that the proposed signal amplification strategy has superior properties and offers the potential to significantly increase the sensitivity of the analysis.

DMTMM-mediated methylamidation for MALDI mass spectrometry analysis of N-glycans with structurally conserved sialic acid residues in biological fluids "via direttissima".

Characterization of serum glycoprotein N-glycans with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) in positive-ion mode needs a derivatization step to stabilize and neutralize the negative charge on sialic acids. The acidic sugars are attached to the end of glycoproteins, glycolipids or gangliosides. Here, we present a method for sialic acid stabilization via modification based on derivatization of carboxylic acid group activated with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) with methylamine. DMTMM substitutes in many processes N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS) as activation reagent due to its better performance and higher stability in water. Glycosylated proteins are used as solid phase support for glycan derivatization and purification from excess of derivatization reagents. We evaluated our glycan analysis method in murine sera and intestinal lavages. The stabilization of sialic acid enables a complete conservation of the glycan structures, in contrast to other methods where sialic acids are partially lost. In BALB/c mouse sera, we detected predominantly mono- and di-sialylated N-glycans with mostly N-Glycolylneuraminic acid (Neu5Gc) and only trace amounts of N-Acetyl neuraminic acid (Neu5Ac). BALB/c mouse intestinal lavages glycoproteins contained asialo N-glycans. DMTMM-mediated methylamidation of N-glycans for MALDI mass spectrometry analysis is a fast and cheap method for structurally conserved glycan derivatization.

Mimicking the Composition and Structure of the Osteochondral Tissue to Fabricate a Heterogeneous Three-Layer Scaffold for the Repair of Osteochondral Defects.

Heterogeneous three-layer scaffolds were fabricated by mimicking the biochemical composition and structure of the hyaline cartilage, calcified cartilage, and subchondral bone of the osteochondral tissue for the repair of osteochondral defects. The hyaline cartilage layer was composed of collagen I (50.0 wt %) and sodium hyaluronate (50.0 wt %). The calcified cartilage layer and subchondral bone layer were composed of collagen I, sodium hyaluronate, and nanohydroxyapatite with different proportions. N-Hydroxysuccinimide/N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride was used to mediate the crosslinking reaction of the amine groups of collagen with carboxyl groups of sodium hyaluronate. The hyaline cartilage layer and calcified cartilage layer were designed as dense structures, while the subchondral bone layer was designed as a relatively loose structure by adjusting the crosslinking degree. The scaffolds displayed a uniform and interconnected porous structure and possessed a high porosity over 85%, which were conducive to cellular adhesion and proliferation. The scaffolds could remain at 50-75% after 30 days of degradation owing to crosslinking, providing enough time for the regeneration of the osteochondral tissue. Especially, the hyaline cartilage layer and calcified cartilage layer preferred to induce the proliferation of chondrocytes, while the subchondral bone layer was more conducive to the proliferation of osteoblasts. In conclusion, the heterogeneous multilayer scaffolds could serve as implant materials for osteochondral reconstruction.

Covalent Immobilization of Lipase on Bacterial Cellulose Membrane and Nanocellulose

The cellulose from Komagataeibacter hansenii is synthesized as a thin film at the surface of glucose based media. Strong acid hydrolysis release sections of crystalline cellulose chains in nanometric scale that leads to persistent suspensions in water. The cellulose anhydro-glucose hydroxyls are suitable to receive functional groups as enzymes, and lipases have great economic value being a valuable model for protein immobilization. In this work both, the membrane of bacterial cellulose as well the nanocellulose produced trough acid hydrolysis, was functionalized with a lipase. The bacterial cellulose membranes were produced by Hestrin-Schramm medium, and nanocelluloses produced from the pristine material was characterized using techniques as 13C solid state NMR and transmission electron microscopy (TEM). The pristine membranes and nanocellulose were functionalized with succinic acid as linker, then lipase was conjugated using EDC (N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride), and NHS (N-Hydroxysuccinimide). The effectiveness of the chemical process was characterized, and the lipase activity were measured. The presence of the succinic acid and amide linkage, as well physical-chemical changes on the functionalized polysaccharide. Hence, we inferred that after immobilization the enzyme maintained its activity in both cellulose and the cellulose membrane.

Albumin Microspheres as “Trans-Ferry-Beads” for Easy Cell Passaging in Cell Culture Technology

Protein hydrogels represent ideal materials for advanced cell culture applications, including 3D-cultivation of even fastidious cells. Key properties of fully functional and, at the same time, economically successful cell culture materials are excellent biocompatibility and advanced fabrication processes allowing their easy production even on a large scale based on affordable compounds. Chemical crosslinking of bovine serum albumin (BSA) with N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) in a water-in-oil emulsion with isoparaffinic oil as the continuous phase and sorbitan monooleate as surfactant generates micro-meter-scale spherical particles. They allow a significant simplification of an indispensable and laborious step in traditional cell culture workflows. This cell passaging (or splitting) to fresh culture vessels/flasks conventionally requires harsh trypsinization, which can be omitted by using the “trans-ferry-beads” presented here. When added to different pre-cultivated adherent cell lines, the beads are efficiently boarded by cells as passengers and can be easily transferred afterward for the embarkment of novel flasks. After this procedure, cells are perfectly viable and show normal growth behavior. Thus, the trans-ferry-beads not only may become extremely affordable as a final product but also may generally replace trypsinization in conventional cell culture, thereby opening new routes for the establishment of optimized and resource-efficient workflows in biological and medical cell culture laboratories.

Glucose-responsive oral insulin delivery platform for one treatment a day in diabetes

Glucose-responsive oral insulin delivery platform for one treatment a day in diabetes