Bioactive specific biomaterials: Present and future

Abstract

-Bioactive biomaterials made of synthetic or artificial polymers substituted with specific chemical functional groups carried by the macromolecular chain are designed t o develop specific interactions with living systems. These soluble or insoluble polymers are derived from polystyrene and dextran. Such functional polymers may be endowed with anticoagulant heparin-like properties and, as a consequence, possess low thrombogenicity when they are in contact with flowing blood. Other functional polymers have been tailored specifically to interact with components of the immune system. Other polymers, in contact with cells can affect both cell growth and cell biological functions or only cell biological activity without necessarily undergoing change in all characteristics. Derived from the above concepts, it is possible to demonstrate that a random statistical distribution of chemical groups along the macromolecular backbone correlates with the biological properties of these polymers.

Control of the blood–polymer interface by plasma treatment

“…being followed by thromboembolic processes and local and systemic undesirable events (adverse and allergic reactions, toxic effects). [3][4][5][6][7] On the other hand, the mechanical and physicochemical properties of implants are affected by the biological environment, yielding possible deterioration and degradation of the material. 8 Obviously, the success of the medical act is strongly dependent on these mutual dynamic interactions, of high and often unpredictable complexity, between the implant surface and the biological environment.…”

“…At the blood–biomaterial interface, within a few seconds after the exposure to blood, various complex processes take place, the adsorption and deposition of blood components (cellular elements, plasma proteins, salts, etc.) being followed by thromboembolic processes and local and systemic undesirable events (adverse and allergic reactions, toxic effects) 3–7. On the other hand, the mechanical and physicochemical properties of implants are affected by the biological environment, yielding possible deterioration and degradation of the material 8.…”

Carboxymethylation of dextran in aqueous alcohol as the first step of the preparation of derivatized dextrans

“…The synthesis of CMDBS sequentially involves three reactions: random carboxymethylation of hydroxy groups on D-glucose units (CM), benzylamidation of the carboxylic groups (B) and sulfonation of phenyl rings and sulfation of free hydroxy groups (S) 4,5) . Their activities are closely depending on the distribution of the substituents along the polymer chain 1,6) and the structure of CMD precursor strongly influences the distribution of B and S groups. In this respect, the correlations between individual CMDBS structures and their corresponding anticoagulant activities have been partially clarified by studying the distribution of CM groups, using 1D and 2D 1 H and 13 C NMR spectroscopy and Monte Carlo simulations 7) .…”

Chiral discrimination phenomena in mixed‐ligand copper(II) complexes with amino acids and 1,3‐dicarbonyl compounds

“…Thus, in the region around 400 nm, the sign of the Cotton effect is determined by the dicarbonyl ligand, while in the region 500-600 nm, the effect of the a-amino acid ligand is dominant. [2][3][4]. Here, a correlation may be established only between the sign of the longer wavelength band of the heteroligand complex and that of the 500-600 nm band of the amino acid complex.…”

“…With this in view, potentiomeric investigations of enantioselectivity in heteroligand amino acid complexes have been carried outla and attempts have been made to relate these results with chromatographic data. 3 While examining enantioselective effects in nonaqueous media, absorption and circular dichroism (CD) spectra4 appeared to be more convenient as compared to the traditional potentiometric titration.…”