An Extracellular Matrix‐Mimicking Hydrogel for Full Thickness Wound Healing in Diabetic Mice

An extracellular matrix‐mimicking hydrogel is developed consisting of a hyaluronan‐derived component with anti‐inflammatory activity, and a gelatin‐derived component offering adhesion sites for cell anchorage. The in situ‐forming hyaluronan‐gelatin (HA‐GEL) hydrogel displays a sponge‐like microporous morphology. Also, HA‐GEL shows a rapid swelling pattern reaching maximum weight swelling ratio within 10 min, while at the equilibrium state, fully swollen hydrogels display an exceedingly high water content with ≈2000% of the dry gel weight. Under typical 2D cell culture conditions, murine 3T3 fibroblasts adhere to, and proliferate on top of the HA‐GEL substrates, which demonstrate that HA‐GEL provides a favorable microenvironment for cell survival, adhesion, and proliferation. In vivo healing study further demonstrates HA‐GEL as a viable and effective treatment option to improve the healing outcome of full thickness wounds in diabetic mice by effectively depleting the inflammatory chemokine monocyte chemoattractant protein‐1 in the wound bed.     

Nanocomposite scaffolds based on gelatin and alginate reinforced by Zn2SiO4 with enhanced mechanical and chemical properties for tissue engineering

Hydrogels have been employed in regenerative treatments for decades because of their biocompatibility and structural similarity to the native extracellular matrix. Injectable hydrogels with interconnected porosity and specific internal structures are momentous for tissue engineering. Here, we develop a group of injectable hydrogels comprised of oxidized alginate (OA)/gelatin (GEL) strengthened by modifying the amount of Zn₂SiO₄ nanoparticles. The physicochemical characteristics of OA/GEL/Zn₂SiO₄ hydrogels were studied by mechanical strength, swelling ratio, and morphology. The outcomes revealed that the mechanical characteristics of hydrogels containing a higher amount of Zn₂SiO₄ (0.12 wt%) improved more than five times than the hydrogels fabricated without Zn₂SiO₄. The in vitro degradation outcomes manifested the degradation of the hydrogel comprising 0.12 wt% Zn₂SiO₄ NPs was slower than one without NPs, and remaining masses of hydrogels depend on different contents of Zn₂SiO₄ NPs. The hydrogel containing Zn₂SiO₄ NPs exhibited less cytotoxicity and good cell attachment than the hydrogels prepared without the nanoparticles. The cell viability and attachment show that the nanocomposite hydrogels are biocompatible (>96%) with great cell adhesion to osteosarcoma cell line MG63 depending on the presence of Zn₂SiO₄. The superior physical, chemical as well as mechanical characteristics of the hydrogels containing Zn₂SiO₄ NPs along with their cytocompatibility suggest that they can introduce as good candidates as scaffolds in tissue engineering.     

Ba2CoCl6: Synthese,Kristallstruktur und spektroskopische Eigenschaften

Ba₂CoCl₆: Synthesis, Crystal Structure, and Spectroscopic Properties Single crystals of Ba₂CoCl₆ were obtained from the binary chlorides BaCl₂ and CoCl₂ in sealed silica ampoules applying the Bridgman technique. According to the X‐ray single crystal structure determination, Ba₂CoCl₆ crystallizes with the monoclinic crystal system (P2₁/n, Z = 4, a = 914.1(1), b = 811.4(1), c = 1279.7(2) pm, β = 90.22(2)°). The structure contains conedgial double octahedra, [Co₂Cl₁₀]^6–, and extra Cl^– anions. These are connected via nine‐coordinate Ba²⁺ cations. Investigations of the absorption properties of the blue Ba₂CoCl₆ show a high‐spin ground state. The absorption spectrum is comparable to that of CoCl₂.     

EMK-Messungen in binären ladungsunsymmetrischen Salzschmelzen aus Bariumchlorid und Alkalimetallchloriden

EMF Measurements in Binary Chargeunsymmetrical Salt Melts of Barium- and Alkali Chlorides The EMF is measured of cells with transference of the type Cl₂[C]/MCl//MCl? BaCl₂(x)/[C]Cl₂ in the molten mixtures BaCl₂? MCl (M ? Li, Na, K, Rb, Cs). From the EMF values and values of activities from another independent methods the transference numbers of the cations Ba²⁺ and M⁺ relative to the chloride ion in the molten mixtures BaCl₂? (Li, Na, K) Cl are calculated. The values of activities for the system BaCl₂? LiCl are calculated from cryoscopic analysis of the phase diagram.     

A universal self‐eroding sacrificial bioink that enables bioprinting at room temperature

Natural polymer‐based hydrogel bioinks are widely used in bioprinting due to their suitability for recapitulation of in vivo cellular activities. However, preservation of the target geometry in a cell‐laden hydrogel is difficult to achieve. The aim of this study was to develop a universal sacrificial bioink that allows high cell viability and a better shape fidelity in the cell‐laden construct. A polysaccharide‐based universal sacrificial bioink was developed for microextrusion‐based bioprinting and was optimized to erode in 48 hours in the cell culture medium without formation of any undesired by‐products. The sacrificial hydrogel was prepared from alginate and agarose via a microwave oven assisted method and bioprinted at room temperature to generate microchannels in the cell‐laden hydrogel or to support a tubular structure and its biocompatibility determined by live/dead assay. Bioprinting time was significantly reduced, down to a few minutes for a large‐scale tissue model (1 minute 52 seconds for a 2 cm tubular structure), by means of a high bioprinting speed up to 25 mm/s. After 48 hours in the cell culture, the sacrificial bioink completely detached from the cell‐laden construct without causing any changes in its printed shape. Cell viability in the cell‐laden construct was observed to be more than 95% at the end of 3‐day culture. This novel sacrificial bioink enables bioprinting at room temperature without affecting oxygen and nutrient penetration into the cell‐laden hydrogel and allows retention of high cell viability and shape fidelity.     

Oxoacidic properties of some Ba-based chloride melts

Solubilities of CdO and ZnO in molten BaCl₂–KCl–NaCl (0.43:0.29:0.28) and BaCl₂–KCl (0.26:0.74) at 700°C have been determined by the potentiometric titration technique. Oxobasicity indices of these melts are estimated as 2.01 and 1.83, respectively. A correlation between oxobasicity indices and the content of most acidic cation (Ba²⁺) is shown to exist.     

Development of Gelatin‐Alginate Hydrogels for Burn Wound Treatment

Hydrogels are interesting as wound dressing for burn wounds to maintain a moist environment. Especially gelatin and alginate based wound dressings show strong potential. Both polymers are modified by introducing photocrosslinkable functionalities and combined to hydrogel films (gel‐MA/alg‐MA). In one protocol gel‐MA films are incubated in alg‐MA solutions and crosslinked afterward into double networks. Another protocol involves blending both and subsequent photocrosslinking. The introduction of alginate into the gelatin matrix results in phase separation with polysaccharide microdomains in a protein matrix. Addition of alg(‐MA) to gel‐MA leads to an increased swelling compared to 100% gelatin and similar to the commercial Aquacel Ag dressing. In vitro tests show better cell adhesion for films which have a lower alginate content and also have superior mechanical properties. The hydrogel dressings exhibit good biocompatibility with adaptable cell attachment properties. An adequate gelatin‐alginate ratio should allow application of the materials as wound dressings for several days without tissue ingrowth.     

Cell(MC3T3‐E1)‐Printed Poly(ϵ‐caprolactone)/Alginate Hybrid Scaffolds for Tissue Regeneration

A new cell‐printed scaffold consisting of poly(ϵ‐caprolactone) (PCL) and cell‐embedded alginate struts is designed. The PCL and alginate struts are stacked in an interdigitated pattern in successive layers to acquire a three‐dimensional (3D) shape. The hybrid scaffold exhibits a two‐phase structure consisting of cell (MC3T3‐E1)‐laden alginate struts able to support biological activity and PCL struts able to provide controllable mechanical support of the cell‐laden alginate struts. The hybrid scaffolds exhibit an impressive increase in tensile modulus and maximum strength compared to pure alginate scaffolds. Laden cells are homogeneously distributed throughout the alginate struts and the entire scaffold, resulting in cell viability of approximately 84%.     

Kristallstruktur von BaGdCl5

Crystal Structure of BaGdCl₅ Colourless single crystals of BaGdCl₅ are obtained from a 1 : 2 molar mixture of BaCl₂ and GdCl₃. It crystallizes with the monoclinic space group C2/c with a = 552.1(2), b = 1925.7(5), c = 687.4(2) pm, β = 93.25(4)° in a new structure. Ba²⁺ and Gd³⁺ have coordination numbers of 8 + 2 and 8, respectively.     

In vitro anti‐proliferative and in silico docking studies of heteroleptic copper(II) complexes of pyridazine‐based ligands and ciprofloxacin

Three heteroleptic copper(II) complexes of the type [Cu(L^1–3)(cf)(ClO₄)] ( 1 – 3 ), where cf = ciprofloxacin, have been synthesized using pyridazine‐based ligands 3‐chloro‐6‐(salicylidenehydrazinyl)pyridazine (HL¹), 3‐chloro‐6‐(4‐diethylaminosalicylidenehydrazinyl)pyridazine (HL²) and 3‐chloro‐6‐(5‐bromosalicylidenehydrazinyl)pyridazine (HL³). Electronic spectral data and magnetic moment values suggest octahedral geometry for the synthesized copper(II) complexes. Electrochemical data of the copper(II) complexes present an irreversible one‐electron reduction wave in the cathodic potential region (E_pc) between ?0.631 and ?0.670 V. Frontier molecular orbital calculations were carried out, and the obtained low‐energy gap supports the bio‐efficacy of the complexes. All the complexes were screened for their in vitro cytotoxicity activity against three human cancerous (breast adenocarcinoma (MCF‐7), hepatoma (HepG‐2) and cervical (HeLa)) and one non‐cancerous (non‐tumorigenic human dermal fibroblast (NHDF)) cell lines using MTT assay, in which complex 2 exhibited higher activity. The apoptosis induction by the complexes was analysed using the Hoechst dye staining method with MCF‐7 cell line, which indicates higher apoptotic activity of complex 2 . A molecular docking study was carried out to ascertain the binding affinity of the synthesized heteroleptic copper(II) complexes with phosphoinositide 3‐kinase gamma (PI3Kγ) receptor.     

Preparation of a Yb(III)‐Incorporated porous polymer by post‐Coordination: Enhancement of gas adsorption and catalytic activity

We synthesized a Yb(III)‐incorporated microporous polymer (Yb‐ADA) and studied its gas adsorption property and catalytic activity. The adamantane‐based porous polymer (ADA) was obtained from an ethynyl‐functionalized adamantane derivative and 2,5‐dibromoterephthalic acid through Sonogashira–Hagihara cross‐coupling. ADA had two carboxyl groups which were used for Yb(III) coordination under basic conditions. The Brunauer‐Emmett‐Teller (BET) surface area of ADA was 970 m² g^?1. As Yb(III) ions were incorporated into ADA, the surface area of the polymer (Yb‐ADA) was reduced to 885 m² g^?1. However, Yb‐ADA exhibited a significantly enhanced CO₂ adsorption capacity despite the reduction of surface area. The CO₂ uptakes of ADA and Yb‐ADA were 1.56 and 2.36 mmol g^?1 at 298 K, respectively. The H₂ uptake of ADA also increased after coordination with Yb(III) from 1.15 to 1.40 wt % at 77 K. Yb‐ADA showed high catalytic activity in the acetalization of 4‐bromobenzaldehyde and furfural with trimethyl orthoformate and could be reused after recovery without severe loss of activity. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 5291–5297     

Copper and Nickel Removal from Aqueous Solutions Using New Chelating Poly[Acrylamide/N‐vinyl pyrrolidone/3‐(2‐hydroxyethyl carbamoyl)acrylic acid] Hydrogels

New poly[Acrylamide/N‐vinyl pyrrolidone/3‐(2‐hydroxyethyl carbamoyl)acrylic acid], poly [AAm/NVP/HECA], chelating hydrogels with different composition of HECA monomer have been prepared via free radical solution polymerization using N,N‐methylene bisacrylamide as a crosslinker. The hydrogels obtained were loaded with metal ions and characterized by FT‐IR spectroscopy, Scanning Electron Microscope (SEM) and Thermogravimatric analysis (TGA). The removal of Cu²⁺ and Ni²⁺ from aqueous solutions by the hydrogel was examined by a batch equilibrium method. The influence of treatment time, pH, initial concentration of the metal ions and HECA content in the feed compositions on the amount of adsorbed metal ions was studied. Swelling of the hydrogel was also carried out in distilled water and metal ion solutions. The removal of the metal ions followed the following order: Ni²⁺>Cu²⁺. The amount of metal ions removed increased with increasing HECA content in the feed composition, treatment time, pH of the medium and initial concentration of metal ions. The desorption of metal ions were carried out using 1 N HCl and 0.5 N H₂SO₄. The poly[AAm/NVP/HECA] hydrogels could be used many times without significantly decreasing their adsorption capacity.     

Eu+2 fluorescence in BaCl2

The Ba_1?xEu_xCl₂ system was studied over wide ranges of x, particularly regarding the fluorescent emission of Eu²⁺. In addition to the commonly observed 5d → 4f band emission sharp line, f → f transitions were observed. Single crystals of Eu²⁺ containing BaCl₂ were grown via the Czochralski technique and many of the optical properties, such as transmission, fluorescence, and excitation, were measured. X-ray and thermal parameters for the Ba_1?xEu_xCl₂ system are also reported.     

Strukturuntersuchungen an Usoviten: Ba2CaMIIV2F14 (MIII = Mn,Fe), Ba2CaMnFe2F14 und Ba2CaCuM2IIIF14 (MIII = Mn,Fe, Ga)

Structural Studies with Usovites: Ba₂CaM^IIV₂F₁₄ (M^III = Mn, Fe), Ba₂CaMnFe₂F₁₄ and Ba₂CaCuM₂^IIIF₁₄ (M^III = Mn, Fe, Ga). Single crystals of six compounds Ba₂CaM^IIM₂^IIIF₁₄ were prepared to refine their usovite type structure (space group C2/c, Z = 4) using X‐ray diffractometer data. The cell parameters of the phases studied with M^IIM₂^III= MnV₂, FeV₂, CuMn₂, MnFe₂, CuFe₂ und CuGa₂ are within the range 1374≤a/pm≤1384, 534≤b/pm≤542, 1474≤c/pm≤1510, 91, 3≤ß/°≤93, 2. The atoms Ca and M^II are incompletely ordered on the 8‐ and 6‐coordinated positions, 4e and 4b, respectively. In the case of Ba₂CaFeV₂F₁₄ and Ba₂CaCuGa₂F₁₄ there is reciprocal substitution (x≈0, 1): (Ca_1‐xM_x^II) (4e) and (M_1‐x^IICa_x) (4b). In the case of the other usovites Ca‐enriched phases Ba₂Ca(M_1‐y^IICa_y)M₂^IIIF₁₄ occured (up to y≈0, 35), exhibiting partial substitution at the octahedral position (4b) only, showing a corresponding increase in M^II‐F distances. The distortion of [M^IIF₆] and [M^IIIF₆] octahedra within the structure is considerably enhanced on replacement by Cu^II and Mn^III. The results of powder magnetic susceptibility measurements of Ba₂CaMnV₂F₁₄ and Ba₂CaFeV₂F₁₄ (T_N≈7K) are reported.     

Über Neue Oxoruthenate vom Typ der 6 L-Perowskite: Ba3SrRu2−xTaxO9 (x = 0,8 und 1,4) mit einem Beitrag über Ba3CaRu2O9

On Novel Oxoruthenates of the 6 L-Perovskite Type: Ba₃SrRu_2?xTa_xO₉ (x = 0.8 and 1.4) with a Comment on Ba₃CaRu₂O₉ Single crystals of the phases Ba₃SrRu_2?xTa_xO₉ [(I): x = 0.8 and (II): x = 1.4] and the compound (III): Ba₃CaRu₂O₉ were prepared by a BaCl₂ flux and investigated by X-ray methods. (I)–(III) crystallizes with hexagonal symmetry space group P6 2c with lattice constants: (I) a = 6.003 Å; c = 15.227 Å; (II) a = 5.988 Å; c = 15.220 Å and (III) a = 5.891 Å; c = 14.571 Å. The crystal structures of these substances corresponds to the 6 layer perovskites with the stacking sequence (hcc)₂. All of them show a so far not described slightly distorted oxygen framework caused by the Sr²⁺ and Ca²⁺ ions.     

{[Ba2(C2O4)(H2O)6](NCS)2}n: a layered mixed‐anion barium oxalate

We present the first example of a compound containing Ba²⁺, C₂O₄²⁻, water and some additional halide or pseudo‐halide anions, viz. hexa‐μ₂‐aqua‐μ₆‐oxalato‐dibarium(II) diiso­thio­cyanate, {[Ba₂(C₂O₄)(H₂O)₆](NCS)₂}_n. The structure consists of positively charged planar covalent layers of Ba²⁺ cations, oxalate anions and water mol­ecules. The first coordination sphere of the Ba²⁺ cation contains six water mol­ecules and four O atoms from two planar oxalate anions. The oxalate anion lies on an inversion centre and is coordinated to six Ba²⁺ cations, each donor O atom being bonded to two cations. Pairs of water mol­ecules are coordinated by two Ba²⁺ cations. The layers are interspersed with non‐coordinated NCS⁻ anions.     

Synthese und Kristallstruktur von Ba6ZnIn2Cl20

Synthesis and Crystal Structure of Ba₆ZnIn₂Cl₂₀ Colourless single crystals of Ba₆ZnIn₂Cl₂₀ are obtained from a 6 : 3 : 2 molar mixture of BaCl₂, ZnCl₂ and InCl₃ at 420 °C in a Pyrex ampoule. It crystallizes with the monoclinic space group P2₁/c (Z = 4) with a = 1957.8(2), b = 1014.69(8), c = 1778.7(2) pm, β = 110.94(1)°, in a new structure. Zn²⁺ is surrounded tetrahedrally and In³⁺ octahedrally by chloride ions. Half of the [InCl₆] octahedra are isolated from each other, the other half shares common edges to form [In₂Cl₁₀] double octahedra. Ba²⁺ has coordination numbers of eight and nine. There are chloride ions that do not belong to Zn²⁺ or In³⁺ so that the formula may be written as Ba₁₂Cl₁₀[ZnCl₄]₂[InCl₆]₂[In₂Cl₁₀].     

Hydrogel Complex Containing the Antimicrobial Peptide HX-12C Accelerates Healing of Infected Wounds

Bacterial infections of the wound surface can be painful for patients, and traditional dressings do not effectively address this problem. In this study, an antimicrobial wound dressing is prepared using a novel antimicrobial peptide, HX-12C. This hydrogel system is based on the natural biomaterials sodium alginate and gelatin, utilizing calcium carbonate as a source of Ca²⁺, and ionic cross-linking is facilitated by lowering the solution pH. The resulting sodium alginate/gelatin HX-12C-loaded hydrogel (CaAGEAM) has good mechanical and adhesion properties, biocompatibility and in vitro degradability. Its extraordinary antibacterial efficacy (>98%) is verified by an antibacterial experiment. More importantly, in vivo experiments further demonstrate its healing-promotion effect, with a 95% wound healing rate by day 9. Tissue staining demonstrates that the hydrogel containing antimicrobial peptides is effective in suppressing inflammation. The dressing promotes wound healing by stimulating the deposition of skin appendages and collagen. The results of this study suggest that composite hydrogels containing antimicrobial peptides are a promising new type of dressing to promote the healing of infected wounds.     

Hierarchical Tubular Structures Grown from the Gel/Liquid Interface

Three dimensional hierarchical materials are widespread in nature but are difficult to synthesize by using self‐assembly/organization. Here, we employ a gel–liquid interface to obtain centimeter‐long ～100 μm diameter tubes with complex mineral wall structures that grow from the interface into solution. The gel, made from gelatin, is loaded with metal chloride salt, whereas the solution is a high pH anion source. Tubes were obtained with a range of cations (Ca²⁺, Sr²⁺, Ba²⁺, Cu²⁺, and Zn²⁺) and anions (CO₃^2? and PO₄^3?). The crystalline phases found in the tube walls corresponded to expectations from solution chemistries and phase solubilities. The growth mechanism is found to be akin to that of chemical gardens. The divalent cations modify the strength of the gelatin gel in a manner that involves not only simple electrostatic screening, but also ion‐specific effects. Thus, tubes were not obtained for those ions and/or concentrations that significantly changed the gel’s mechanical structure. At high Cu²⁺ loading, for example, vertical convection bands, not Liesegang bands, were observed in the gels.     

Alginate/Polyoxyethylene and Alginate/Gelatin Hydrogels: Preparation,Characterization, and Application in Tissue Engineering

Hydrogels are attractive biomaterials for three-dimensional cell culture and tissue engineering applications. The preparation of hydrogels using alginate and gelatin provides cross-linked hydrophilic polymers that can swell but do not dissolve in water. In this work, we first reinforced pure alginate by using polyoxyethylene as a supporting material. In an alginate/PEO sample that contains 20 % polyoxyethylene, we obtained a stable hydrogel for cell culture experiments. We also prepared a stable alginate/gelatin hydrogel by cross-linking a periodate-oxidized alginate with another functional component such as gelatin. The hydrogels were found to have a high fluid uptake. In this work, preparation, characterization, swelling, and surface properties of these scaffold materials were described. Lyophilized scaffolds obtained from hydrogels were used for cell viability experiments, and the results were presented in detail.