乙酰化对壳聚糖-明胶海绵结构和性能的影响

用乙酸酐对壳聚糖与明胶共混物进行乙酰化,然后冷冻干燥制备乙酰化壳聚糖-明胶海绵,并研究乙酰化对海绵结构与性能的影响。用盐酸环丙沙星作模型药物,探讨载药海绵的抑菌效果。结果表明:制得的海绵具有多孔结构,随壳聚糖在混合物中含量的增加,海绵的吸水率和保水率先增后减;随着乙酰化程度的提高,海绵的吸水率先减后增,而保水率与吸水率的变化规律相反。酶对海绵的降解率不受壳聚糖和明胶混合比例的影响,但随海绵乙酰化程度的增加而增加。载药海绵的抑菌效果与海绵中壳聚糖含量有关。     

Heterocyclic superbases: retrospective and current trends

The structural principles known to date serving as the basis for the design of heterocyclic compounds with anomalously high basicity (superbasicity) are reviewed. A general classification is given for such superbases as proton sponges, compounds that are similar to proton sponges but are not sponges (proton-sponge-like), and proton traps.     

Evaluation of the use of liquid dishwashing compounds to control bacteria in kitchen sponges

A test procedure for evaluating the effect of adding commercial liquid hand dishwashing detergents to kitchen sponges to control microbial growth is described. Claims for this type of application are being made on dishwashing detergents throughout the world. In this evaluation, commercially available kitchen sponges were stripped of antimicrobial compounds. Sponges were then inoculated with a pool of 7 microorganisms which consisted of gram positives, gram negatives, and yeast. Inoculated sponges were treated with the detergent as recommended by the manufacturer and allowed to incubate for 16 h at ambient temperature. Surviving microorganisms were then quantitated using either the spiral or pour plate method. Tests were run using both clean sponges and sponges soiled with 0.5% nonfat dry milk (NFDM). Untreated sponges showed stasis or slightly increased bacterial populations after the incubation period in the absence of NFDM. Significant increases of up to 3 log cfu/mL were observed for untreated sponges when soiled with NFDM. Statistically significant reductions were observed for clean sponges (99.8-99.9998%) and sponges soiled with NFDM (87.6-99.9%) when detergents making "antibacterial sponge" claims were added to the inoculated sponges. Statistically significant differences between detergents making "antibacterial sponge" claims were also observed.     

Thoroughly Hydrophilized Electrospun Poly(L-Lactide)/ Poly(ε-Caprolactone) Sponges for Tissue Engineering Application

Biodegradable electrospun sponges are of interest for various applications including tissue engineering, drug release, dental therapy, plant protection, and plant fertilization. Biodegradable electrospun poly(l -lactide)/poly(ε-caprolactone) (PLLA/PCL) blend fiber-based sponge with hierarchical pore structure is inherently hydrophobic, which is disadvantageous for application in tissue engineering, fertilization, and drug delivery. Contact angles and model studies for staining with a hydrophilic dye for untreated, plasma-treated, and surfactant-treated PLLA/PCL sponges are reported. Thorough hydrophilization of PLLA/PCL sponges is found only with surfactant-treated sponges. The MTT assay on the leachates from the sponges does not indicate any cell incompatibility. Furthermore, the cell proliferation and penetration of the hydrophilized sponges are verified by in vitro cell culture studies using MG63 and human fibroblast cells.     

Kinase inhibitory, haemolytic and cytotoxic activity of three deep-water sponges from North Western Australia and their fatty acid composition

The c-AMP dependent protein kinase (PKA) inhibition, haemolytic activity, and cytoxicity of 21 extracts obtained from North Western Australian sponges collected from depths of 84-135 m were investigated. Hexane extracts from Ircinia/Sarcotragus sp. and Geodia sp. displayed PKA inhibitory activities of 100 and 97% respectively (at 100 microg/mL), while aq. methanol extracts from Haliclona sp. exhibited potent haemolytic activity (75%) and hexane extracts from Geodia sp. were highly toxic (88%) to the brine shrimp Artemia franciscana. As the non-polar extracts gave the greatest PKA inhibition, these were further analysed by GC-MS and 29 fatty acids were identified in the highest proportions in Ircinia/Sarcotragus sp. > Haliclona sp. > Geodia sp. In contrast to shallow-water sponges that are dominated by polyunsaturated fatty acids with a high percentage of long chain fatty acids, LCFAs (C24-C30), the deep-sea sponges investigated herein were all found to be rich in saturated fatty acids, in particular C14-C20 fatty acids, including odd and branched chain fatty acids, with only low levels (0-10%) of LCFAs. Screening of the PKA inhibitory activity of a series of commercially available fatty acids identified C14-C18 fatty acids as possessing significant PKA inhibitory activity that may contribute to the activity observed in the sponges studied.     

Crystal water molecules as magnetic tuners in molecular metamagnets exhibiting antiferro-ferro-paramagnetic transitions

We studied the effects of the number of crystal water molecules on the magnetic behavior of {[Ni(en)(2)](3)[Fe(CN)(6)](2)·xH(2)O}(n) (1-3) (where en = ethylenediamine and x = 3, 2, or 0) coordination polymers by (57)Fe M?ssbauer spectroscopy, single-crystal X-ray diffraction, and magnetization measurements. Magnetic phase diagrams constructed for all three compounds indicate that they behave as metamagnets exhibiting very rare field-induced antiferro-ferro-paramagnetic transitions. The number of crystal water molecules has a major effect on the Néel temperature, critical field, and magnetic hardness of the compounds in the ferromagnetic state. Moreover, the systems behave as molecular magnetic sponges, changing their magnetic properties due to the controllable and reversible dehydration/hydration process.     

添加剂对活性人工皮肤胶原海绵支架材料的影响

研究了壳聚糖、硫酸软骨素和肝素对胶原海绵理化性质和生物相容性的影响。结果表明：添加壳聚糖后胶原海绵的孔隙率和暖水率下降,添加硫酸软骨素后上升,而添加肝素后无明显变化。三种添加剂均可减少基质收缩,增强材料的抗降解性能,但种问差异不明显。与纯胶原海绵相比,复合海绵可进一步促进细胞的吸附和增殖,其中添加壳聚糖和肝素的效果相当,优于硫酸软骨素,有望应用于构建组织工程化人工皮肤。     

Preparation and morphology control of three‐dimensional interconnected microporous PDMS for oil sorption

This study described an approach to impart controlled morphology and improved pore interconnectivity to poly(dimethylsiloxane) (PDMS) sponges for oil sorption by partially fusing the sugar particles together prior to creation of a continuous PDMS matrix. PDMS sponges with high absorption capacity, low water pickup, and remarkable reusability were fabricated by the polymerization of the PDMS prepolymer and a curing agent in cyclohexane. The PDMS sponge showed oil absorbency in the range from 790% to 4000% for various oils solvents, with the maximum absorption capacity reaching up to 23 times of its weight. Compressive modulus of PDMS subjected to sugar fusion for 24 hr was significantly increased to 1900 Mpa. The sponge also exhibited excellent repellency to corrosive strong acid and alkali. Besides, oil can be quickly adsorbed in tens of seconds and maintained for several months. Furthermore, PDMS sponges showed little loss of their absorption capacities and owned weights after 20 absorbing/recovering cycles. Copyright © 2015 John Wiley & Sons, Ltd.     

Facile synthesis of microfibrillated cellulose/organosilicon/polydopamine composite sponges with flame retardant properties

Cellulose composite sponges with good mechanical, heat-insulating and flame retardant properties were constructed by a facile method. Simultaneous polymerization of dopamine and hydrolysis of organosilicon in the suspension of microfibrillated cellulose could provide the stiffness and flame ratardancy of the composite sponges. The hybrid sponges had low density (15.1–28.5 mg/cm³) and desirable compression strength (76.6–135.8 kPa). Scanning electron microscopy (SEM) and thermal conductivity tests revealed that the sponges are composed of a three-dimensional cellulosic network and the porous structure endowed them low thermal conductivity [~0.046 W/(m K)]. With the addition of organosilicon (45 wt%) and polydopamine (PDA) (10 wt%), a 456% improvement in BET surface area of the sponge could be achieved. The limiting oxygen index (LOI) of the composite sponge could be as high as 29.5 with 15 wt% PDA and could self-extinguish at once when it was removed from torch. That was owing to the promoted materials carbonization ability of silicon and radical scavenging activity of dopamine.     

Structure and synthesis of 2-aminoimidazole alkaloids from Leucetta and Clathrina sponges

Marine sponges belonging to the Calcarea family have been studied for some time and have yielded a wide variety of structurally unique secondary metabolites. In particular, these sponges have produced a large number of bioactive alkaloids containing an imidazole heterocycle, typically substituted with two benzylic fragments at various locations around the azole nucleus and at various oxidation states. This review will describe the isolation, structural determination and synthetic studies towards this growing class of natural products.     

Natural Products from the Marine Sponge Subgenus Reniera

Marine sponges are one of the prolific producers of bioactive natural products with therapeutic potential. As an important subgenus of Haliclona, Reniera sponges are mainly distributed in the Mediterranean Sea and Atlantic area, and had been chemically investigated for over four decades. By an extensive literature search, this review first makes a comprehensive summary of all natural products from Reniera sponges and their endozoic microbes, as well as biological properties. Perspectives on strengthening the chemical study of Reniera sponges for new drug-lead discovery are provided in this work.     

Low‐Density Open Cellular Sponges as Functional Materials

Low‐density macroporous sponges with densities less than 100 mg cm⁻³ are both a challenge and an opportunity for advanced chemistry and material science. The challenge lies in the precise preparation of the sponges with property combinations that lead to novel applications. Bottom‐up and top‐down chemical and engineering methods for the preparation of sponges are a major focus of this Review, with an emphasis on carbon and polymer materials. The light weight, sustainability, breathability, special wetting characteristics, large mass transfer, mechanical stability, and large pore volume are typical characteristics of sponges made of advanced materials and could lead to novel applications. Some selected sponge properties and potential applications are discussed.     

Synthesis and characterization of boron nitride sponges as a novel support for metal nanoparticles

This paper describes a simple synthetic route for the synthesis of hexagonal boron nitride (h-BN) powders with high specific surface area, in which BBr3, NH4Cl and Al powders are used as starting materials. The structure and composition of the powders were characterized by electron diffraction, Fourier transformation infrared spectroscopy and X-ray photoelectron spectroscopy in the selected area. X-ray diffraction shows wide peaks of crystalline h-BN with the particle size on the nanometer scale, and transmission electron microscopy reveals that the products have a novel spongy morphology. Silver nanoparticles loaded h-BN sponges were prepared via a one-step synthesis method. Different reaction conditions for the formation of h-BN sponges were also investigated.     

Influence of sample preparation on the determination of the elemental composition of fresh water sponges by inductively coupled plasma mass spectrometry

To find the optimal way of the sample preparation of sponges for the determination of their elemental composition, three techniques of digestion were tested: acidic (mixtures of nitric, chloric, and hydrofluoric acids and hydrogen peroxide) upon heating in open vessels, autoclave-assisted at higher temperature and pressure, and decomposition in microwave ovens (MW). Using inductively coupled plasma mass spectrometry (ICP MS), we determined the concentrations of 23 elements in sponges Baikalospongia bacillifera Dubowski, 1880. The accuracy checks have demonstrated a good agreement between the measured and assured values. The attained limits of detection ranged from 32 mg/kg (for Al after autoclave digestion) to 0.1–0.2 μg/kg (for Tl, open acidic with HClO₄ and MW decomposition). The relative standard deviation varied from rather modest values (for Cu, Cs, Ba, autoclave decomposition; Se, open acidic HClO₄-free; Zn, open acidic with HClO₄) to 30% (Be, Tl, Pb, autoclave decomposition; Be, Cr, Ga, Pb, open HClO₄-free acidic digestion), 40% (Cs, MW), and 60% (Se, open acidic with HClO₄). Different ways of digestion showed good compatibility of the results for the elements under study, except for Li, Sr, and Se. For Cr and Co (open acidic with HClO₄), Cr, Ni, and As (MW), the method appeared insufficiently sensitive.     

Anti-inflammatory metabolites from marine sponges

Marine sponges are a rich source of biologically active secondary metabolites with novel chemical structures. Eighty four anti-inflammatory compounds have been isolated from marine sponges. This is the first comprehensive review presenting the structures and anti-inflammatory activities of marine sponge metabolites. (100 references).     

Preparation of Collagen‐Glycosaminoglycan Sponges with Open Surface Porous Structures Using Ice Particulate Template Method

Funnel‐like sponges of collagen incorporated with glycosaminoglycan (GAG) were prepared by freeze‐drying using ice particulates as templates. The funnel‐like collagen‐GAG sponges showed similar porous structures to those of funnel‐like collagen sponges. The funnel‐like collagen‐GAG and collagen sponges have one top surface layer and one bulk porous layer. The large, top surface pores were determined by ice particulates that were used as templates, and the inner bulk pores were determined by freezing temperature. The funnel‐like pore structures facilitated homogenous cell distribution, improved cell viability, and resulted in homogenous tissue formation. Incorporation of GAG increased the mechanical property and cell viability of collagen sponges.

     

中国南海海绵化学成分研究进展

综述了近十年来我国南海海绵化学成分的研究进展情况 ,主要包括萜类、含氮化合物、甾醇等 ,以及部分化合物的生理活性。     

Construction of conductive hydroxyethyl cellulose/soy protein isolate/polypyrrole composite sponges and their performances

Cellulose - In the present study, we have in situ synthesized polypyrrole (PPy) on the hydroxyethyl cellulose/soy protein isolate (HEC/SPI) sponges to construct electro-conductive HEC/SPI/PPy...     

具有垂直孔道的壳聚糖乳酸盐海绵的制备及体外释药模型的拟合分析

先将壳聚糖(CH)经乳酸改性制成壳聚糖乳酸盐(LCH)以改善其溶解性, 然后通过加入冰晶生长引导剂叔丁醇(TBA), 在特制的定向冷冻装置中冻结, 再经冷冻干燥后, 制成了一种圆柱形的海绵体, 其内部具有垂直方向上的孔道结构. 通过控制叔丁醇的浓度, 制备了具有不同孔径及孔隙率的海绵样品. 以红霉素为模型药物, 研究了具有自身降解溶蚀功能的LCH样品的体外释药模型, 结果表明, LCH样品的释药过程主要分为基体溶蚀控释和药物后扩散2个阶段. 其中基体控释阶段符合Couarraze释药模型.     

Analysis and discrimination of ten different sponges by multi-step infrared spectroscopy

In this study,a convenient method using multi-step infrared spectroscopy,including Fourier transform infrared spectroscopy(FT-IR),second derivative infrared spectroscopy(SD-IR) and two-dimensional correlation infrared spectroscopy(2DCOS-IR),was employed to analyze and discriminate ten marine sponges from two classes collected from the Xisha Islands in the South China Sea.Each sponge had an exclusive macroscopic fingerprint.From the IR spectra,it was noted that the main ingredient of calcareous sponges was calcium carbonate,but that of demosponges was proteins.For sponges from the same genus or having highly similar chemical profile(IR spectral profile),SD-IR and 2DCOS-IR were applied to successfully reveal the tiny differences.It was demonstrated that the multi-step infrared spectroscopy was a feasible and objective approach for marine sponge identification.