**3. Conclusion**

Modified chitosan with antibacterial potentials superior to native chitosan was prepared. To achieve this goal, new route of chemical modification to graft extra amine groups onto native chitosan has been presented. As a result of modification, the nitrogen content of modified chitosan increased by about 30%.

FT-IR, TGA analysis and solubility test confirmed the occurrence of amination process. The solubility near neutral media, pH 6.0, increases by about 65%. Using glycerol as plasticizer improved the surface roughness, water uptake, and the mechanical properties of aminated chitosan membranes while its water vapor permeability was reduced.

The modified chitosan membranes were evaluated as wound dressing biomaterial and show high profile. Its bacterial cell inhibition capability against gram negative and gram positive was improved in the range of 40 – 100%. Moreover, no hemolytic effect was observed. In addition, its biodegradability was not affected significantly. However, the cytotoxicity was increased, not in a dramatic way, and the water vapor permeability also reduced which limit the application of modified chitosane membranes as wound dressing. In the meanwhile, further investigations are conduction in this direction to overcome these drawbacks through quaterinization process.

In conclusion the new route of modification was found successful and is recommended for preparation of novel chitosan biomaterials.

#### **4. References**

366 Infrared Spectroscopy – Life and Biomedical Sciences

(45-47). Fischer et al (48) confirmed these observations for PLL and PEI, but argued that cationized human serum albumin and starburst dendimer, which also contain primary amino groups, showed only moderate cytotoxic effects. They conclude that not only the type of amino function but also the charge density and arrangement is an important factor for determining cytotoxicity and hence biocompatibility (48). This may be explains the moderate increment of cytotoxicity of modified chitosan, table 10, in which the cell viability % decreases by about 10%, although the nitrogen content increases by about 30%. Only part of this increment is referred to primary amino groups and the other part is referred to

The biodegradability of chitosan and aminated chitosan was measured as produced reduced sugar results from the cellulase enzyme action on the chitosan. Table 11 represents the OD of the total reduced sugar produced from chitosan and aminated chitosan hydrolysis with cellulase enzyme for 30 minutes at 50oC. It was observed that the degradation in the case of chitosan is higher than the aminated chitosan. This may be attributed to the steric effect result from increase the amine content and presence of benzene ring of PBQ on the polymer chains which consequently reduced the accessibility of the aminated chitosan to enzyme

> **Polymer OD**  Chitosan 0.747 Aminated chitosan 0.643

Table 11. Biodegradability effect of cellulase enzyme on the chitosan and aminated chitosan

Modified chitosan with antibacterial potentials superior to native chitosan was prepared. To achieve this goal, new route of chemical modification to graft extra amine groups onto native chitosan has been presented. As a result of modification, the nitrogen content of

FT-IR, TGA analysis and solubility test confirmed the occurrence of amination process. The solubility near neutral media, pH 6.0, increases by about 65%. Using glycerol as plasticizer improved the surface roughness, water uptake, and the mechanical properties of aminated

The modified chitosan membranes were evaluated as wound dressing biomaterial and show high profile. Its bacterial cell inhibition capability against gram negative and gram positive was improved in the range of 40 – 100%. Moreover, no hemolytic effect was observed. In addition, its biodegradability was not affected significantly. However, the cytotoxicity was increased, not in a dramatic way, and the water vapor permeability also reduced which limit the application of modified chitosane membranes as wound dressing. In the meanwhile, further investigations are conduction in this direction to overcome these drawbacks through

chitosan membranes while its water vapor permeability was reduced.

secondary amino groups (figure 1), which is less toxic.

**Biodegradability** 

hydrolytic activity.

**3. Conclusion** 

quaterinization process.

(30 minute, at 50oC and pH 7)

modified chitosan increased by about 30%.


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