Decyl Groups Research Articles

Impact of hydrophobic modification on biocompatibility of Alaska pollock gelatin microparticles.

This study investigates the impact of hydrophobic modification on the immunogenicity, cytotoxicity, and inflammatory response of Alaska pollock gelatin (ApGltn) microparticles (MPs). Gelatin, known for its inherent biocompatibility, was modified with decyl group (C10) to explore potential alterations in its interaction with the immune system. Immunogenicity was evaluated through the measurement of material-specific IgM and IgG responses, indicating no significant increase post-modification. Cytotoxicity against Caco-2 cell lines and NF-κB-mediated LPS-induced inflammation were also assessed, revealing no exacerbation by the modified MPs. Furthermore, C10 modification with different types of linkage such as secondary amine and amide structure did not influence immune reactivity. These findings suggest that C10 modification maintains the non-immunogenicity and biocompatibility of gelatin MPs, supporting their potential use in biomedical applications.

Improved hydration property of tissue adhesive/hemostatic microparticle based on hydrophobically-modified Alaska pollock gelatin

The management of bleeding is an important aspect of endoscopic surgery to avoid excessive blood loss and minimize pain. In clinical settings, sprayable hemostatic particles are used for their easy delivery, adaptability to irregular shapes, and rapid hydration. However, conventional hemostatic particles present challenges associated with tissue adhesion. In a previous study, we reported tissue adhesive microparticles (C10-sa-MPs) derived from Alaska pollock gelatin modified with decyl groups (C10-sa-ApGltn) using secondary amines as linkages. The C10-sa-MPs adhere to soft tissues through a hydration mechanism. However, their application as a hemostatic agent was limited by their long hydration times, attributed to their high hydrophobicity. In this study, we present a new type microparticle, C10-am-MPs, synthesized by incorporating decanoyl group modifications into ApGltn (C10-am-ApGltn), using amide bonds as linkages. C10-am-MPs exhibited enhanced hydration characteristics compared to C10-sa-MPs, attributed to superior water absorption facilitated by amide bonds rather than secondary amines. Furthermore, C10-am-MPs demonstrated comparable tissue adhesion properties and underwater adhesion stability to C10-sa-MPs. Notably, C10-am-MPs exhibited accelerated blood coagulation in vitro compared to C10-sa-MPs. The application of C10-am-MPs in an in vivo rat liver hemorrhage model resulted in a hemostatic effect comparable to a commercially available hemostatic particle. These findings highlight the potential utility of C10-am-MPs as an effective hemostatic agent for endoscopic procedures and surgical interventions.

Self-assembled low molecular weight chitosan-based cationic micelle for improved water solubility, stability and sustained release of α-tocopherol.

New amphiphilic low molecular weight chitosan-graft-nicotinic acid bearing decyl groups (LCND) was synthesized by two-step reaction and spontaneously assembled into cationic micelle by ultra-sonication method to improve water solubility and photostability properties of α-tocopherol. The chemical structure of LCND was characterized and physical properties of cationic micelle were evaluated. Results displayed that cationic micelle exhibited strong self-assemble ability with nanoscale spherical morphology and showed best loading ability with loading content of 18.50% when the feeding ratio of LCND to α-tocopherol reached 10:3. Meanwhile, the greatly enhanced water solubility, photostability and sustained release behavior of α-tocopherol in cationic micelle were observed. The cumulative release of α-tocopherol in cationic micelle reached up 82.18% within 96h while free α-tocopherol was completely released within 10h. Additionally, release kinetics models were also fitted. The LCND cationic micelle could be promising nanocarrier for improving the physicochemical properties of α-tocopherol in food fields.

Sprayable tissue adhesive microparticle–magnetic nanoparticle composites for local cancer hyperthermia

Incomplete removal of early-stage gastrointestinal cancers by endoscopic treatments often leads to recurrence induced by residual cancer cells. To completely remove or kill cancer tissues and cells and prevent recurrence, chemotherapy, radiotherapy, and hyperthermia using biomaterials with drugs or nanomaterials are usually administered following endoscopic treatments. However, there are few biomaterials that can be applied using endoscopic devices to locally kill cancer tissues and cells. We previously reported that decyl group-modified Alaska pollock gelatin-based microparticles (denoted C10MPs) can adhere to gastrointestinal tissues under wet conditions through the formation of a colloidal gel driven by hydrophobic interactions. In this study, we combined C10MPs with superparamagnetic iron oxide nanoparticles (SPIONs) to develop a sprayable heat-generating nanomaterial (denoted SP/C10MP) for local hyperthermia of gastrointestinal cancers. The rheological property, tissue adhesion strength, burst strength, and underwater stability of SP/C10MP were improved through decyl group modification and SPION addition. Moreover, SP/C10MP that adhered to gastrointestinal tissues formed a colloidal gel, which locally generated heat in response to an alternating magnetic field. SP/C10MP successfully killed cancer tissues and cells in colon cancer-bearing mouse models in vitro and in vivo. Therefore, SP/C10MP has the potential to locally kill residual cancer tissues and cells after endoscopic treatments.

Ionothermal Approach to Homo- and Heteroleptic Alkylation of Tellurido Mercurate Clusters for Assembly in Lamellar Crystal Structures.

The selective methylation and butylation of chalcogenido metalate clusters by utilizing imidazolium-based ionic liquids turned out to be not only a comparably mild but at the same time also the only known method for postsynthetic alkylation of such species in order to increase their solubility. For additional impact on the crystal structures, selective alkylation with longer alkyl chains was addressed by utilizing the ionic liquid (C10C1Im)[BF4] (C10 = decyl group at position 1 and C1 = methyl group at position 3 of the cation's Im = imidazolium ring) for ionothermal syntheses of functionalized tellurido mercurate clusters. Herein, we report three novel compounds, two of which comprise cluster anions that exhibit a selective organic functionalization of their terminal telluride ligands upon in situ alkylation with the ionic liquid: [Hg6Te6(Te2)2(TeDec)2]6- (in 1; Dec = decyl) represents the first decylated chalcogenido metalate cluster. A unique heteroleptic functionalization, combining methylation and decylation, was achieved for the second cluster, [Hg6Te6(Te2)2(TeDec)(TeMe)]6- (in 2; Me = methyl). The third cluster is purely inorganic, but based on the same cluster core architecture: [Hg4Te2(Te2)2(Te3)2]4- (in 3) comprises a tritelluride unit instead of two HgTeR groups (R = Me, Dec). As a consequence of the long alkyl chains, both at the cluster and at the charge-compensating cations, all three crystal structures are characterized by lamellar assemblies of cations and anions. For further comparison of the properties of the organometallic versus purely inorganic compounds, vibrational and optical properties of crystalline samples of the compounds comprising clusters 1 and 3 were studied by means of infrared, Raman, and UV-visible spectroscopy. The results clearly show the effect of the presence of an organic decoration (in 1) relative to its absence (in 3), reflected by a red shift of the band gap energy (1 → 3) and a replacement of the Te-C bands (in 1) with bands for tritelluride units (in 3).

Improved Swelling Property of Tissue Adhesive Hydrogels Based on α-Cyclodextrin/Decyl Group-Modified Alaska Pollock Gelatin Inclusion Complexes.

Adhesives/sealants are used after suturing to prevent leakage of cerebrospinal fluid from an anastomotic site. Commercial adhesives/sealants have been used to close the cerebral dura. However, swelling of the cured adhesives/sealants induces increased intracranial pressure and decreases the strength of the seal. In the present study, tissue adhesive hydrogels with improved swelling property using inclusion complex composed of α-cyclodextrin (αCD) and decyl group (C10)-modified Alaska pollock-derived gelatin (C10-ApGltn) with a high degree of substitution (DS) (>20 mol%) are developed. Viscosity of C10-ApGltn with a high DS solution remarkably decreased by the addition of αCD. The resulting αCD/C10-ApGltn adhesive hydrogel composed of αCD/C10-ApGltn inclusion complexes and poly(ethylene glycol) (PEG)-based crosslinker showed improved swelling property after immersion in saline. Also, the resulting adhesive has a significantly higher burst strength than fibrin-based adhesives and is as strong as a PEG-based adhesive. Quantitative analysis of αCD revealed that the improved swelling property of the resulting adhesive hydrogels is induced by the release of αCD from cured adhesive, and the subsequent assembly of decyl groups in the saline. These results suggest that adhesives developed using the αCD/C10-ApGltn inclusion complex can be useful for closing the cerebral dura mater.

Speeds of sound and densities in imidazolium-based ionic liquids under elevated pressures: New experimental data and modelling by spinodal method and CP-PC-SAFT

In this study reports a comprehensive physicochemical experimental characterization of a homologous series of ionic liquids containing 3-ethyl-1-alkoxymethylimidazolium bis(trifluoromethylsulfonyl)imide with linear n-alkyl chains in an alkoxymethyl substituent from the hexyl up to the decyl group. An influence of the n-alkyl chain length on the thermophysical properties was investigated in the temperature and pressure ranges 293.75 – 373.25 K and 1.019 – 1962 bar. Accuracies of the Critical Point-Based Perturbed-Chain Statistical Associating Fluid Theory (CP-PC-SAFT) and the spinodal method in modelling these data were compared.

Optimization of the conditions for the immobilization of glycopolypeptides on hydrophobic silica particulates and simple purification of lectin using glycopolypeptide-immobilized particulates

Glycopolypeptide-immobilized particulates exhibit high binding selectivities and affinities for several analytes. However, to date, the conditions for the synthesis of glycopolypeptide-immobilized particulates have not been optimized and the application of these particulates as carriers for affinity chromatography has not been reported. Accordingly, herein, as a model compound for determining the optimal conditions for the immobilization of an artificial glycopolymer on hexyl-containing hybrid silica particulates (HSPs), the glycopolypeptide poly [GlcNAcβ1,4GlcNAc-β-NHCO-(CH2)5NH-/CH3(CH2)9NH-/γ-PGA] (3) containing multivalent chitobiose moieties and multivalent decyl groups with a γ-polyglutamic acid backbone was synthesized. Immobilization of 3 on HSPs under each condition was evaluated by a lectin-binding assay using wheat germ (Triticum vulgaris) agglutinin (WGA), which is an N-acetylglucosamine-binding lectin. As a result, the optimal immobilization conditions for HSPs at 25 mg/mL were obtained at dimethyl sulfoxide (DMSO) concentration of reaction solvent in the range of 1(DMSO):9(water) to 4(DMSO):6(water) and a compound 3 concentration in the range of 125 nM–1250 nM. Furthermore, the influence of the alkyl group structure introduced into glycopolypeptide for imparting hydrophobicity to it on the immobilization of glycopolypeptide on HSPs was investigated. As a result of comparing three types, poly [GlcNAcβ1,4GlcNAc-β-NHCO-(CH2)5NH-/γ-PGA] (1) with no alkyl group, poly [GlcNAcβ1,4GlcNAc-β-NHCO-(CH2)5NH-/CH3(CH2)4NH-/γ-PGA] (2) with a pentyl group, and 3 with a decyl group, 3 showed the best immobilization efficiency on HSPs. Finally, 1 mg 3-immobilized HSPs prepared under the optimum conditions adsorbed approximately 7.5 μg WGA in a structure-specific manner. We also achieved a simple WGA purification from raw wheat germ extract as a practical example using 3-immobilized HSPs. We believe that in the future, these glycopolypeptide-immobilized particulates will be used not only for the purification of plant lectins, but also as specific adsorbents for various lectins-like substances such as in vivo lectins, pathogenic viruses, and toxin proteins.

Prevention of postoperative adhesion with a colloidal gel based on decyl group-modified Alaska pollock gelatin microparticles

Postoperative adhesion, bonding of the abdominal wall to damaged organs, causes severe complications after abdominal surgery. Despite the availability of physical barriers (i.e., solutions, films, and hydrogels), adhesion prevention materials that are a single-substance system with stability in wet tissue and ease of use have not been reported. Here, we report a microparticle based, sprayable adhesion prevention material comprising decyl group modified Alaska pollock gelatin (C10-ApGltn). C10-ApGltn microparticles (C10-MPs) were prepared by a coacervation method, freeze drying, and thermal crosslinking. The C10-MPs adhered to and formed a colloidal gel layer on intestinal serosal tissue by hydration without any crosslinking agents. After hydration of the C10-MPs, the resulting colloidal gel layer did not adhere to other tissues. Additionally, the C10-MP colloidal gel layer formed on the stomach serosal tissue showed stability when submersed in saline for 2 days. The colloidal gel layer also showed tissue followability. An in vivo rat adhesion model revealed that C10-MP colloidal gel layer on the cecum and abdominal wall defects effectively reduced postoperative adhesion and induced tissue remodeling, including re-mesothelialization. Therefore, C10-MPs are a potential anti-adhesion material for preventing postoperative adhesion. Statement of significanceWe evaluated the postoperative adhesion prevention ability of a colloidal gel based on decyl group modified Alaska pollock gelatin (ApGltn) microparticles (C10-MPs). These microparticles are sprayable and form a colloidal gel with only hydration on the gastrointestinal tissue. We revealed that the modification of the decyl group into ApGltn improved the stability of C10-MP colloidal gel on the tissue by hydrophobic interaction in the in-vitro experiments. The gel prevented postoperative adhesion by being a physical barrier in the in-vivo rat adhesion model.

Prevention of Postoperative Adhesion with a Colloidal Gel Based on Decyl Group Modified Alaska Pollock Gelatin Microparticles

Prevention of Postoperative Adhesion with a Colloidal Gel Based on Decyl Group Modified Alaska Pollock Gelatin Microparticles

Comparative study of hydrophobically modified gelatin-based sealant with commercially available sealants.

Air leakage is one of the major complications related to pulmonary surgeries. To reduce this complication, we developed a decyl group (C10)-modified Alaska pollock gelatin (ApGltn) (C10-ApGltn) sealant and evaluated its practical performance against commercially available sealants, Beriplast® and DuraSeal®. C10-ApGltn was synthesized by reductive amination of the amino groups in ApGltn with decanal. C10-ApGltn was crosslinked with a poly(ethylene glycol)-based crosslinker to form a tissue sealant. The crosslinking time of the C10-ApGltn sealant was fast enough for curing on tissue and application as a spray system. Although the percent swelling of C10-ApGltn and DuraSeal was significantly greater than Beriplast, C10-ApGltn and DuraSeal exhibited excellent tissue sealing properties on pleura tissue under a long-term moist condition. Additionally, C10-ApGltn and DuraSeal did not cause severe inflammatory responses in a rat subcutaneous example. Therefore, C10-ApGltn sealant had comparable tissue sealing properties to DuraSeal under a moist condition, indicating the potential of C10-ApGltn sealant for pulmonary surgeries.

Enzymatic Hydrolysis-Responsive Supramolecular Hydrogels Composed of Maltose-Coupled Amphiphilic Ureas.

Maltose is a ubiquitous disaccharide produced by the hydrolysis of starch. Amphiphilic ureas bearing hydrophilic maltose moiety were synthesized via the following three steps: I) construction of urea derivatives by the condensation of 4-nitrophenyl isocyanate and alkylamines, II) reduction of the nitro group by hydrogenation, and III) an aminoglycosylation reaction of the amino group and the unprotected maltose. These amphiphilic ureas functioned as low molecular weight hydrogelators, and the mixtures of the amphipathic ureas and water formed supramolecular hydrogels. The gelation ability largely depended on the chain length of the alkyl group of the amphiphilic urea; amphipathic urea having a decyl group had the highest gelation ability (minimum gelation concentration=0.4 mM). The physical properties of the supramolecular hydrogels were evaluated by measuring their thermal stability and dynamic viscoelasticity. These supramolecular hydrogels underwent gel-to-sol phase transition upon the addition of α-glucosidase as a result of the α-glucosidase-catalyzed hydrolysis of the maltose moiety of the amphipathic urea.

PH-Sensitive branched β-glucan-modified liposomes for activation of antigen presenting cells and induction of antitumor immunity.

Induction of cellular immunity is important for effective cancer immunotherapy. Although various antigen carriers for cancer immunotherapy have been developed to date, balancing efficient antigen delivery to antigen presenting cells (APCs) and their activation via innate immune receptors, both of which are crucially important for the induction of strong cellular immunity, remains challenging. For this study, branched β-glucan was selected as an intrinsically immunity-stimulating and biocompatible material. It was engineered to develop multifunctional liposomal cancer vaccines capable of efficient interactions with APCs and subsequent activation of the cells. Hydroxy groups of branched β-glucan (Aquaβ) were modified with 3-methylglutaric acid ester and decyl groups, respectively, to provide pH-sensitivity and anchoring capability to the liposomal membrane. The modification efficiency of Aquaβ derivatives to the liposomes was significantly high compared with linear β-glucan (curdlan) derivatives. Aquaβ derivative-modified liposomes released their contents in response to weakly acidic pH. As a model antigenic protein, ovalbumin (OVA)-loaded liposomes modified with Aquaβ derivatives interacted efficiently with dendritic cells, and induced inflammatory cytokine secretion from the cells. Subcutaneous administration of Aquaβ derivative-modified liposomes suppressed the growth of the E.G7-OVA tumor significantly compared with curdlan derivative-modified liposomes. Aquaβ derivative-modified liposomes induced the increase of CD8+ T cells, and polarized macrophages to the antitumor M1-phenotype within the tumor microenvironment. Therefore, pH-sensitive Aquaβ derivatives can be promising materials for liposomal antigen delivery systems to induce antitumor immune responses efficiently.

Generation of Axially Polar Ferroelectricity in a Columnar Liquid Crystal Phase by Introducing Chirality

AbstractAxially polar ferroelectric columnar liquid crystals (AP‐FCLCs) are materials in which the molecules are self‐organized into axially polar columns and exhibit switching and holding of their polar directions. If the polar directions along the columnar axis can be controlled by using a nanosized electrode, AP‐FCLCs have the potential to realize ultrahigh‐density memory devices. Though switching polarities in columnar liquid crystal phases have been studied by many scientists, it remains difficult to realize bistable switching. In this study, it is found that replacement of the normal alkyl groups (decyl groups) with chiral groups ((S)‐citronellyl groups) in an N,N’‐bis(3,4,5‐trialkoxyphenyl)urea realizes perfect ferroelectricity in the rectangular columnar liquid crystal phase, and it is confirmed that the phase is an AP‐FCLC phase. The differences in the properties and molecular packing structures between the achiral and chiral urea compounds are investigated. Furthermore, the mechanism for achieving ferroelectricity by introduction of the chiral alkyl chains is postulated.

Synthesis of new hetero-arylidene-9(10H)-anthrone derivatives and their biological evaluation.

New hetero-arylidene-9(10H)-anthrone derivatives (1) were synthesized from reaction of 1,2-dimethyl-3-alkyl imidazolium salts (2) and 9-anthracenecarboxaldehyde. Ion exchange of the anion with dioctyl sulfosuccinate and lithium bis(trifluoromethanesulfonyl)imide led to the preparation of other derivatives. The antiproliferative effect of the compounds was evaluated in human ovarian (A2780) and colorectal (HCT116) carcinoma cell lines and in normal primary human fibroblasts. Compound 1 presented an antiproliferative effect related to the imidazolium pattern of substitution with compounds having a decyl group at the R-position (1c and 3c) showing the highest cytotoxic activities in all cell lines independently of the counter ion. Compounds 1b and 1c internalize A2780 cancer cells via a passive or an active transport, respectively, inducing A2780 cell death via an extrinsic apoptosis (1b) or intrinsic apoptosis and oncosis (1c). The localization of both compounds in the cytoplasm coupled to the absence of reactive oxygen species (ROS) induction suggest that the mechanisms of toxicity might be different than those of other anthracyclines currently used in chemotherapy.

Enzyme responsive properties of amphiphilic urea supramolecular hydrogels

Amphiphilic ureas with hydrophilic lactose groups form transparent supramolecular hydrogels. Their gelation abilities are sensitive to the length of the alkyl chain. Amphiphilic ureas bearing hexyl, heptyl, octyl, and nonyl groups form supramolecular hydrogels, but amphiphilic ureas bearing decyl groups or longer alkyl groups do not show gelation ability. The gradual gel-to-sol phase transition of the supramolecular hydrogel is triggered by adding β-galactosidase (β-Gal) as a result of enzymatic hydrolysis of the lactose moiety. Supramolecular hydrogels could stably entrap cationic organic dyes, such as rhodamine 6G (Rh6G), even in water. The entrapped Rh6G could be gradually released in the presence of β-Gal, along with the gel-to-sol phase transition. Lactose-coupled amphiphilic ureas are worked as low-molecular-weight hydrogelators (LMWHGs). Their gelation abilities are sensitive to the length of the hydrophobic alkyl chain. Gradual gel-to-sol phase transition of the supramolecular hydrogel was occurred by adding β-galactosidase (β-Gal) as a result of enzymatic hydrolysis of the lactose moiety. Supramolecular hydrogels could stably entrap cationic organic dyes even in water. The entrapped dye could be gradually released in the presence of β-Gal, along with the gel-to-sol phase transition.

Amphiphilic Polypeptoids Rupture Vesicle Bilayers To Form Peptoid-Lipid Fragments Effective in Enhancing Hydrophobic Drug Delivery.

Peptoids are highly biocompatible pseudopeptidic polyglycines with designable substituents on the nitrogen atoms. The therapeutic and drug-carrying potential of these materials requires a fundamental understanding of their interactions with lipid bilayers. In this work, we use amphiphilic polypeptoids with up to 100 monomeric units where a significant fraction (26%) of the nitrogen atoms are functionalized with decyl groups (hydrophobes) that insert into the lipid bilayer through the hydrophobic effect. These hydrophobically modified polypeptoids (HMPs) insert their hydrophobes into lipid bilayers creating instabilities that lead to the rupture of vesicles. At low HMP concentrations, such rupture leads to the creation of large fragments which remarkably anchor to intact vesicles through the hydrophobic effect. At high HMP concentrations, all vesicles rupture to smaller HMP-lipid fragments of the order of 10 nm. We show that the technique for such nanoscale polymer-lipid fragments can be exploited to sustain highly hydrophobic drug species in solution. Using the kinase inhibitor, Sorafenib as a model drug, it is shown that HMP-lipid fragments containing the drug can efficiently enter a hepatocellular carcinoma cell line (Huh 7.5), indicating the use of such fragments as drug delivery nanocarriers.

A novel series of cyclophosphazene derivatives containing imidazolium ionic liquids with variable alkyl groups and their physicochemical properties

A series of substituted cyclophosphazene derivatives containing imidazolium ionic liquids having variable alkyl groups were successfully synthesized and characterized by different spectroscopic techniques. The synthesized ionic liquids with butyl, pentyl, hexyl, heptyl, octyl and decyl groups were designated as IL1, IL2, IL3, IL4, IL5, and IL6 respectively. Physicochemical studies in terms of viscosity, density, thermal stability and conductivity were carried out as a function of temperature and molecular weight to see the lengthening effect of the alkyl group. The viscosity and density of the ionic liquids tend to decrease linearly with temperature. Further, experimental values of viscosity and density calculated the viscosity index, thermal expansion coefficient and molar volume. Similarly, all other physicochemical properties were evaluated to study structure-property correlation.

Cyclic Cell-Penetrating Peptides with Single Hydrophobic Groups.

A new family of cyclic cell-penetrating peptides (CPPs) has been discovered; they differ from previously reported cyclic CPPs by containing only a single hydrophobic residue. The optimal CPP structure consists of four arginine residues and a hydrophobic residue with a long alkyl chain (e.g., a decyl group) in a cyclohexapeptide ring. The most active member of this family, CPP 17, has an intrinsic cellular entry efficiency similar to that of cyclic CPP12, the most active CPP reported to date. However, CPP 17 is 2.8 times more active than CPP12 under high serum protein concentrations, presumably because of the lower protein binding. CPP 17 enters the cell primarily by direct translocation at a relatively low concentration (≥5 μm).

Synthesis, surface properties and antimicrobial performance of novel gemini pyridinium surfactants

A series of novel gemini pyridinium surfactants with different alkyl chains were synthesized and characterized. The surface properties and aggregation behavior of the gemini surfactants in solution were studied. The gemini pyridinium salts exhibit higher surface activity than quaternary ammonium salts and can form vesicles above critical micellization concentration (CMC). The antimicrobial performance of these surfactants against E. coli was investigated and compared with those of quaternary ammonium salts. Alkyl chain length has a significant effect on the antimicrobial activity of the gemini surfactants, and the surfactant with decyl group showed more effective antimicrobial activity than quaternary ammonium salts. The high cationic charge density on the polar head group and the strong adsorption tendency confer relatively high antimicrobial of the gemini surfactants.