Three-dimensional network of cords: The main component of basement membranes

1988 ◽  
Vol 181 (4) ◽  
pp. 341-358 ◽  
Author(s):  
S. Inoue ◽  
C. P. Leblond
Keyword(s):  
Three Dimensional ◽  
Basement Membranes ◽  
Dimensional Network ◽  
Main Component

scholarly journals Mechanical and Swelling Characteristics of Kappa-carrageenin/Poly-N-isopropylacrylamide Blend Hydrogels

2017 ◽  
Vol 4 (1) ◽  
pp. 61
Author(s):  
Zhang Yalong ◽  
Zhang Yanqun ◽  
Yi Min ◽  
Ha Hongfei
Keyword(s):  
Three Dimensional ◽  
Polymer Chains ◽  
Linear Polymer ◽  
Temperature Sensitive ◽  
Swelling Properties ◽  
Radiation Technology ◽  
Dimensional Network ◽  
Swelling Characteristics ◽  
Unreacted Monomer ◽  
Main Component

Two- or multi-component hydrogels consisting of the three-dimensional network of polymer chains play more and more significant role in the field of biomaterials such as contact lens, burn dressing drug delivery systems etc or in some technical fields such as gel actuators, sensors, absorbents etc. In the work, a novel blend hydrogel composed of kappa-carrageenin (KC) and polyisopropylacrylamide (PNIPAAm) was prepared via gamma-radiation technology at room temperature. The main component of the hydrogels is a typical temperature sensitive polymer PNIPAAm. As the second component, KC is a kind of natural macromolecules. The properties of the gels, such as gel strength, and swelling behavior were investigated. The incorporation of relatively small content (up to 5 wt.%) of KC could obviously improve the mechanical properties and swelling capacity. 3% KC content in the blend hydrogel is preferable for better strength and swelling properties. On the other hand, as a kind of polysaccharide, KC would be degraded by γ-rays; so<br />suitable dose must be controlled carefully. Here the total dose used was controlled below 3 kGy. KC is soluble in water. If the hydrogels synthesized in the work were as usually extracted in water or other polar solvent such as methanol, the KC in hydrogels would be also washed out completely together with unreacted monomer and linear polymer, and the action of KC in the blend hydrogels would be disappeared. Otherwise, the results published before showed that the unreacted monomer and linear polymer in the hydrogels were very small, no more than 3-5%, which would not affect the properties of the hydrogels.

scholarly journals The incubation of laminin, collagen IV, and heparan sulfate proteoglycan at 35 degrees C yields basement membrane-like structures.

1989 ◽  
Vol 108 (4) ◽  
pp. 1567-1574 ◽  
Author(s):  
D S Grant ◽  
C P Leblond ◽  
H K Kleinman ◽  
S Inoue ◽  
J R Hassell
Keyword(s):  
Basement Membrane ◽  
Heparan Sulfate ◽  
Three Dimensional ◽  
Collagen Iv ◽  
Heparan Sulfate Proteoglycan ◽  
Basement Membranes ◽  
Sulfate Proteoglycan ◽  
Lamina Densa ◽  
Dimensional Network ◽  
Type C

Three basement membrane components, laminin, collagen IV, and heparan sulfate proteoglycan, were mixed and incubated at 35 degrees C for 1 h, during which a precipitate formed. Centrifugation yielded a pellet which was fixed in either potassium permanganate for ultrastructural studies, or in formaldehyde for Lowicryl embedding and immunolabeling with protein A-gold or anti-rabbit immunoglobulin-gold. Three types of structures were observed and called types A, B, and C. Type B consisted of 30-50-nm-wide strips that were dispersed or associated into a honeycomb-like pattern, but showed no similarity with basement membranes. Immunolabeling revealed that type B strips only contained heparan sulfate proteoglycan. The structure was attributed to self-assembly of this proteoglycan. Type A consisted of irregular strands of material that usually accumulated into semisolid groups. Like basement membrane, the strands contained laminin, collagen IV, and heparan sulfate proteoglycan, and, at high magnification, they appeared as a three-dimensional network of cord-like elements whose thickness averaged approximately 3 nm. But, unlike the neatly layered basement membranes, the type A strands were arranged in a random, disorderly manner. Type C structures were convoluted sheets composed of a uniform, dense, central layer which exhibited a few extensions on both surfaces and was similar in appearance and thickness to the lamina densa of basement membranes. Immunolabeling showed that laminin, collagen IV, and proteoglycan were colocalized in the type C sheets. At high magnification, the sheets appeared as a three-dimensional network of cords averaging approximately 3 nm. Hence, the organization, composition, and ultrastructure of type C sheets made them similar to the lamina densa of authentic basement membranes.

Development of Mucoadhesive Buccal Drug Delivery System of Propranolol Hydrochloride Using Aster ericoides Mucilage

2020 ◽  
Vol 10 (2) ◽  
pp. 133-148
Author(s):  
Ankaj Kaundal ◽  
Pravin Kumar ◽  
Rajendra Awasthi ◽  
Giriraj T. Kulkarni
Keyword(s):  
Buccal Cavity ◽  
Three Dimensional ◽  
Hot Water ◽  
Fickian Diffusion ◽  
Aster Ericoides ◽  
Dimensional Network ◽  
Buccal Tablet ◽  
Significant Difference ◽  
Volunteer Group

Aim: The study was aimed to develop mucoadhesive buccal tablets using Aster ericoides leaves mucilage. Background : Mucilages are naturally occurring high-molecular-weight polyuronides, which have been extensively studied for their application in different pharmaceutical dosage forms. Objective: The objective of the present research was to establish the mucilage isolated from the leaves of Aster ericoides as an excipient for the formulation of the mucoadhesive buccal tablet. Method: The mucilage was isolated from the leaves of Aster ericoides by maceration, precipitated with acetone and characterized. Tablets were prepared using wet granulation technique and evaluated for various official tests. Results: The mucilage was found to be non-toxic on A-431 and Vero cell lines. It was insoluble but swellable in cold and hot water. The results indicate that mucilage can form a three-dimensional network. The pH of the mucilage (6.82 ± 0.13) indicated that it might be non-irritant to the buccal cavity. The mucilage was found to be free from microbes. The release of drug was by Fickian diffusion. The in vivo buccal tablet acceptance was 80%. No significant difference between the diastolic blood pressure of standard and Aster tablets treated volunteer group was recorded. Conclusion: The mucilage was found to be non-toxic on A-431 and Vero cell lines. It was insoluble but swellable in cold and hot water. The results indicate that mucilage can form a three-dimensional network. The pH of the mucilage (6.82 ± 0.13) indicated that it might be non-irritant to the buccal cavity. The mucilage was found to be free from microbes. The release of drug was by Fickian diffusion. The in vivo buccal tablet acceptance was 80%. No significant difference between the diastolic blood pressure of standard and Aster tablets treated volunteer group was recorded. Other: However, to prove the potency of the polymer, in vivo bioavailability studies in human volunteers are needed along with chronic toxicity studies in suitable animal models.

scholarly journals Crystal structure of K[Hg(SCN)3] – a redetermination

2014 ◽  
Vol 70 (9) ◽  
pp. i46-i46 ◽  
Author(s):  
Matthias Weil ◽  
Thomas Häusler
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Three Dimensional ◽  
Lattice Parameters ◽  
Bond Lengths ◽  
Dimensional Network ◽  
Anisotropic Displacement Parameters ◽  
Precision And Accuracy ◽  
Standard Deviations ◽  
Atomic Coordinates

The crystal structure of the room-temperature modification of K[Hg(SCN)3], potassium trithiocyanatomercurate(II), was redetermined based on modern CCD data. In comparison with the previous report [Zhdanov & Sanadze (1952).Zh. Fiz. Khim.26, 469–478], reliability factors, standard deviations of lattice parameters and atomic coordinates, as well as anisotropic displacement parameters, were revealed for all atoms. The higher precision and accuracy of the model is, for example, reflected by the Hg—S bond lengths of 2.3954 (11), 2.4481 (8) and 2.7653 (6) Å in comparison with values of 2.24, 2.43 and 2.77 Å. All atoms in the crystal structure are located on mirror planes. The Hg2+cation is surrounded by four S atoms in a seesaw shape [S—Hg—S angles range from 94.65 (2) to 154.06 (3)°]. The HgS4polyhedra share a common S atom, building up chains extending parallel to [010]. All S atoms of the resulting1∞[HgS2/1S2/2] chains are also part of SCN−anions that link these chains with the K+cations into a three-dimensional network. The K—N bond lengths of the distorted KN7polyhedra lie between 2.926 (2) and 3.051 (3) Å.

scholarly journals Construction of the Cellulose Nanofibers (CNFs) Aerogel Loading TiO2 NPs and Its Application in Disposal of Organic Pollutants

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1841
Author(s):  
Kang Li ◽  
Xuejie Zhang ◽  
Yan Qin ◽  
Ying Li
Keyword(s):  
High Efficiency ◽  
Sol Gel ◽  
Cellulose Nanofibers ◽  
Three Dimensional ◽  
Good Mechanical Property ◽  
Polar Groups ◽  
Dimensional Network ◽  
Natural Polysaccharide ◽  
Valuable Method ◽  
Adsorption Capability

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.

scholarly journals Enhanced bacterial disinfection by CuI–BiOI/rGO hydrogel under visible light irradiation

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20446-20456
Author(s):  
Xi Ma ◽  
Ziwei Wang ◽  
Haoguo Yang ◽  
Yiqiu Zhang ◽  
Zizhong Zhang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Visible Light ◽  
Network Structure ◽  
Visible Light Irradiation ◽  
Three Dimensional ◽  
Light Irradiation ◽  
Transport Capacity ◽  
Highly Efficient ◽  
Dimensional Network ◽  
Bacterial Disinfection

Compared with traditional layered graphene, graphene hydrogels have been used to construct highly efficient visible light-excited photocatalysts due to their particular three-dimensional network structure and efficient electron transport capacity.

scholarly journals Investigations of polyethylene of raised temperature resistance service performance using autoclave test under sour medium conditions

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 346-354
Author(s):  
Guoquan Qi ◽  
Hongxia Yan ◽  
Dongtao Qi ◽  
Houbu Li ◽  
Lushi Kong ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Service Performance ◽  
Degree Of Branching ◽  
Temperature Resistance ◽  
Temperature Conditions ◽  
Dimensional Network ◽  
Gas Medium ◽  
Better Than

Abstract The chapter deals with the performance evaluation of the polyethylene of raised temperature resistance (PE-RT) and polyethylene (PE) using autoclave test under sour oil and gas medium conditions. The analyses of performance changes showed that PE-RT has good media resistance at 60°C. As the temperature increases, its mechanical properties decrease, accompanied by an increase in weight. Comparative analyses showed that no matter what temperature conditions are, PE-RT media resistance is better than PE80. The better media resistance of PE-RT depends on its higher degree of branching. Short branches are distributed between the crystals to form a connection between the crystals, thereby improving its heat resistance and stress under high-temperature conditions. PE-RT forms an excellent three-dimensional network structure through copolymerization, ensuring that it has better media resistance than PE80. However, the mechanical performance will be attenuated due to the high service temperature.

Effects of Velvet Antler Polypeptide-Collagen/Chitosan Materials on Proliferation of Osteoblast

2013 ◽  
Vol 380-384 ◽  
pp. 4295-4298
Author(s):  
Wen He Zhu ◽  
Jun Jie Xu ◽  
Wei Zhang ◽  
Yan Li ◽  
Xiao Jing Lu ◽  
...  
Keyword(s):  
Drug Treatment ◽  
Bone Defect ◽  
Three Dimensional ◽  
Chitosan Scaffold ◽  
Release Drug ◽  
Dimensional Network ◽  
Velvet Antler ◽  
Result Show ◽  
Long Time ◽  
Velvet Antler Polypeptide

A highly osteogenic hybrid bioabsorbable scaffold was developed for bone reconstruction. Though the use of a bioabsorbable collagen and chitosan scaffold for loading velvet antler polypeptide to repair bone defect and drug treatment. Velvet antler polypeptide and collagen were extracted for developing the compounded material. The SEM results show that the collagen and chitosan scaffold maintain the natural three dimensional network structures. The cell proliferation experiment result show that the can promote the osteoblast proliferation for a long time . These results indicated that this compound scaffold can sustainable to release drug and is a good material in bone defect and drug treatment.

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