Chitosan and Derivatives as Bioactive Materials

Anti-inflamatory action Biodegradable Cytocompatible Antimicrobial Angiogenesis stimulation Macrophages activation Granulation and scar formation Absorbion enchacer 

The biological properties of these compounds strongly depend on their solubility in water and other commonly used solvents. In its crystalline form, chitosan is normally insoluble in aqueous solutions above pH 7 however, in dilute acids, the protonated free amino groups facilitate the solubility of the molecule. The pKa of primary amino groups depends closely on DA, so the solubility of chitosan is also dependent on DA [6]. Being a highly insoluble and chemically rather unreactive material, chitin has a much lower applicability than chitosan. Recently, there has been growing interest in the chemical modification of chitosan and chitin [32-35] in order to improve their solubility and extend their applications [7,19,36,37]. 

Knowledge of the microstructure of chitosan samples is essential for understanding the structure-property-activity relationships of chitin and chitosan products [ 18,38-42]. To date, only the effect of weight-averaged molecular weight (MW) and degree results 

Analgesic DA Anticholestemic Mw -I Antioxidant DA Mw -I Haemostatic DA Mucoadhesion DAX Mw T Permeation enchancing effect DAX Mw T Antitumour Mw X 

Over the past years there has been a strong development towards chitosan-based gels as functional restorative biomaterials. This has favored the inclusion of antioxidant-containing materials, antifungal and pain rehef medication into the chitosan molecule and then into the dental restorative material. However, to include any material before its cytotoxicity is known could be disastrous, as the tooth pulp cells could be temporarily or permanently damaged. 

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