scholarly journals Strategies to Functionalize the Anionic Biopolymer Na-Alginate without Restricting Its Polyelectrolyte Properties

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 919 ◽  
Author(s):  
Luca Szabó ◽  
Sandrine Gerber-Lemaire ◽  
Christine Wandrey
Keyword(s):  
Biological Activity ◽  
Biomedical Applications ◽  
Recent Progress ◽  
Analytical Techniques ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Special Focus ◽  
Hydrogel Formation ◽  
Alginate Hydrogels ◽  
Derivatives Of

The natural anionic polyelectrolyte alginate and its derivatives are of particular interest for pharmaceutical and biomedical applications. Most interesting for such applications are alginate hydrogels, which can be processed into various shapes, self-standing or at surfaces. Increasing efforts are underway to functionalize the alginate macromolecules prior to hydrogel formation in order to overcome the shortcomings of purely ionically cross-linked alginate hydrogels that are hindering the progress of several sophisticated biomedical applications. Particularly promising are derivatives of alginate, which allow simultaneous ionic and covalent cross-linking to improve the physical properties and add biological activity to the hydrogel. This review will report recent progress in alginate modification and functionalization with special focus on synthesis procedures, which completely conserve the ionic functionality of the carboxyl groups along the backbone. Recent advances in analytical techniques and instrumentation supported the goal-directed modification and functionalization.

Biomedical applications of methionine-based systems

2021 ◽  
Author(s):  
Jie Liu ◽  
Jun Huang ◽  
Peikun Xin ◽  
Guiting Liu ◽  
Jun Wu
Keyword(s):  
Liver Disease ◽  
Cancer Treatment ◽  
Biomedical Applications ◽  
Recent Progress ◽  
Functional Modification ◽  
Disease Therapy ◽  
Derivatives Of

Spurred by the structure, metabolism, and derivatives of methionine, this review systematically summarizes its recent progress in functional modification, cancer treatment, liver disease therapy.

Silica/organosilica cross-linked block copolymer micelles: a versatile theranostic platform

2017 ◽  
Vol 46 (3) ◽  
pp. 569-585 ◽  
Author(s):  
Dechao Niu ◽  
Yongsheng Li ◽  
Jianlin Shi
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Hybrid Materials ◽  
Biomedical Applications ◽  
Recent Progress ◽  
Amphiphilic Block Copolymers ◽  
Cross Linking ◽  
Design Synthesis ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles

Silica/organosilica cross-linked block copolymer micelles are a novel class of hybrid materials that combine the advantages of amphiphilic block copolymers and silica/organosilica cross-linking agents into one unit. This Tutorial Review summarizes the recent progress in the design, synthesis and biomedical applications of various silica/organosilica cross-linked block copolymer micelles.

Chitosan and Its Derivatives - Biomaterials with Diverse Biological Activity for Manifold Applications

2019 ◽  
Vol 19 (9) ◽  
pp. 737-750 ◽  
Author(s):  
Paulina Paul ◽  
Beata Kolesinska ◽  
Witold Sujka
Keyword(s):  
Biological Activity ◽  
Biomedical Applications ◽  
Chemical Properties ◽  
Alkaline Solutions ◽  
Chemical Modifications ◽  
Solubility In Water ◽  
Chitosan Derivatives ◽  
Main Obstacle ◽  
Derivatives Of ◽  
Diverse Biological Activity

Derived from chitin, chitosan is a natural polycationic linear polysaccharide being the second most abundant polymer next to cellulose. The main obstacle in the wide use of chitosan is its almost complete lack of solubility in water and alkaline solutions. To break this obstacle, the structure of chitosan is subjected to modification, improving its physic-chemical properties and facilitating application as components of composites or hydrogels. Derivatives of chitosan are biomaterials useful for different purposes because of their lack of toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the methods of chemical modifications of chitosan which allow to obtain tailor- made properties required for a variety of biomedical applications. Selected pharmaceutical and biomedical applications of chitosan derivatives are also highlighted. Possibility to manage waste from arthropod and crab processing is also emphasized.

Carbodiimide-mediated conjugation of hippuric acid to concanavalin A: retention of ligand binding and hemagglutinating activities

1986 ◽  
Vol 64 (12) ◽  
pp. 1366-1371 ◽  
Author(s):  
James F. Preston III ◽  
Ronald S. Hencin
Keyword(s):  
Biological Activity ◽  
Reaction Time ◽  
Ligand Binding ◽  
Small Molecules ◽  
Concanavalin A ◽  
Hippuric Acid ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Amino Groups ◽  
Hemagglutination Titer

Conditions for conjugating small molecules with reactive carboxyl groups to concanavalin A (ConA), with retention of biological activity of the lectin, are described. Hippuric acid was conjugated to reactive amino groups on ConA with N-ethyl-N′-(dimethylaminopropyl)carbodiimide under conditions in which neither inter- nor intra-molecular cross-linking was detectable. These same conditions provided for the loading of variable amounts of hippurate as a function of reaction time; conjugates were synthesized with 9.6 mol hippurate∙mol ConA−1. Conjugation in the presence of 0.1 M phosphate provided a condition for limiting the extent of coupling; only amide linkages were formed. These conjugates retained both the ability to bind ligands and the hemagglutination titer of the native lectin.

Influence of Calcium Ions on the Plant Cell Surface: Membrane Fusions and Conformational Changes

1974 ◽  
Vol 32 ◽  
pp. 154-155
Author(s):  
D. James Morré ◽  
Charles E. Bracker ◽  
William J. VanDerWoude
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Conformational Changes ◽  
Calcium Ions ◽  
Surface Membrane ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Ultrastructural Evidence ◽  
Glycine Max L ◽  
Wall Extensibility

Calcium ions in the concentration range 5-100 mM inhibit auxin-induced cell elongation and wall extensibility of plant stems. Inhibition of wall extensibility requires that the tissue be living; growth inhibition cannot be explained on the basis of cross-linking of carboxyl groups of cell wall uronides by calcium ions. In this study, ultrastructural evidence was sought for an interaction of calcium ions with some component other than the wall at the cell surface of soybean (Glycine max (L.) Merr.) hypocotyls.

Synthesis and Biological Potentials of Quinoline Analogues: A Review of Literature

2019 ◽  
Vol 16 (7) ◽  
pp. 653-688 ◽  
Author(s):  
Leena Kumari ◽  
Salahuddin ◽  
Avijit Mazumder ◽  
Daman Pandey ◽  
Mohammad Shahar Yar ◽  
...  
Keyword(s):  
Biological Activity ◽  
Heterocyclic Compounds ◽  
Building Blocks ◽  
Vital Role ◽  
Review Of Literature ◽  
Drug Discovery Process ◽  
Active Compounds ◽  
Lead Compounds ◽  
Synthetic Approaches ◽  
Derivatives Of

Heterocyclic compounds are well known for their different biological activity. The heterocyclic analogs are the building blocks for synthesis of the pharmaceutical active compounds in the organic chemistry. These derivatives show various type of biological activity like anticancer, antiinflammatory, anti-microbial, anti-convulsant, anti-malarial, anti-hypertensive, etc. From the last decade research showed that the quinoline analogs plays a vital role in the development of newer medicinal active compounds for treating various type of disease. Quinoline reported for their antiviral, anticancer, anti-microbial and anti-inflammatory activity. This review will summarize the various synthetic approaches for synthesis of quinoline derivatives and to check their biological activity. Derivatives of quinoline moiety plays very important role in the development of various types of newer drugs and it can be used as lead compounds for future investigation in the field of drug discovery process.

Synthesis and Biological Activity of 28-Amide Derivatives of 23-Hydroxy Betulinic Acid as Antitumor Agent Candidates

2013 ◽  
Vol 9 (7) ◽  
pp. 920-925 ◽  
Author(s):  
Yi Bi ◽  
Jinyi Xu ◽  
Fei Sun ◽  
Xiaoming Wu ◽  
Wencai Ye ◽  
...  
Keyword(s):  
Biological Activity ◽  
Betulinic Acid ◽  
Antitumor Agent ◽  
Amide Derivatives ◽  
Derivatives Of

The melanocyte stimulating activity of N-nitroso-2-chloroethyl-carbamoyl derivatives of α-melanotropin fragments

1988 ◽  
Vol 53 (11) ◽  
pp. 2574-2582 ◽  
Author(s):  
Hedvig Medzihradszky-Schweiger ◽  
Helga Süli-Vargha ◽  
József Bódi ◽  
Kálmán Medzihradszky
Keyword(s):  
Biological Activity ◽  
Active Site ◽  
Frog Skin ◽  
Terminal Sequence ◽  
Subsequent Reaction ◽  
Affinity Labels ◽  
Derivatives Of

A number of N-nitroso-2-chloroethyl-carbamoyl (Q(NO)) derivatives of α-melanotropin fragments have been synthesized and their effect on the frog skin melanocytes studied. Peptides substituted in this way possess the biological activity of the parent compounds, indicating that they preserved their receptor recognizing ability. These compounds can therefore serve as affinity labels. Some of these derivatives, related to the C-terminal sequence of α-melanotropin show prolonged darkening reaction, which does not influence the subsequent reaction of melanocytes with α-melanotropin. The Q(NO)-derivative of a fragment derived from the classical active site of the hormone shows, however, inhibition of the effect of α-melanotropin. It can be concluded that the latter peptide acts through the melanotropin receptor, while others, related to the C-terminal sequence of the hormone through another mechanism.

scholarly journals How to Improve Physico-Chemical Properties of Silk Fibroin Materials for Biomedical Applications?—Blending and Cross-Linking of Silk Fibroin—A Review

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1510
Author(s):  
Sylwia Grabska-Zielińska ◽  
Alina Sionkowska
Keyword(s):  
Silk Fibroin ◽  
Biomedical Applications ◽  
Magnetic Particles ◽  
Chemical Properties ◽  
Ternary Mixtures ◽  
Cross Linking ◽  
Advantages And Disadvantages ◽  
Physico Chemical ◽  
Binary And Ternary Mixtures ◽  
To Receive

This review supplies a report on fresh advances in the field of silk fibroin (SF) biopolymer and its blends with biopolymers as new biomaterials. The review also includes a subsection about silk fibroin mixtures with synthetic polymers. Silk fibroin is commonly used to receive biomaterials. However, the materials based on pure polymer present low mechanical parameters, and high enzymatic degradation rate. These properties can be problematic for tissue engineering applications. An increased interest in two- and three-component mixtures and chemically cross-linked materials has been observed due to their improved physico-chemical properties. These materials can be attractive and desirable for both academic, and, industrial attention because they expose improvements in properties required in the biomedical field. The structure, forms, methods of preparation, and some physico-chemical properties of silk fibroin are discussed in this review. Detailed examples are also given from scientific reports and practical experiments. The most common biopolymers: collagen (Coll), chitosan (CTS), alginate (AL), and hyaluronic acid (HA) are discussed as components of silk fibroin-based mixtures. Examples of binary and ternary mixtures, composites with the addition of magnetic particles, hydroxyapatite or titanium dioxide are also included and given. Additionally, the advantages and disadvantages of chemical, physical, and enzymatic cross-linking were demonstrated.

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