Top Journals	Publications
International Journal of Biological Macromolecules	11
International Journal of Pharmaceutics	7
Biomaterials	6
Acta Biomaterialia	6

Table: Journals with the most publications about chitosan and chitosan derivatives.
Source: GoPubMed

As already described in the previous article “The antimicrobial and skin regenerative effect of chitosan-based nanoparticles” there is an all time multitude of studies about the antimicrobial effect of chitosan. And so also this month there has a lot of research work been done in this field. Two articles will be introduced below.

Further abstracts of interesting articles can be found on GoPubMed.

Evaluation and insights into chitosan antimicrobial activity against anaerobic oral pathogens

E.M. Costa, S. Silva, C. Pina, F.K. Tavaria, M.M. Pintado; Anaerobe; April, 27 2012

The objective of the study was to evaluate the antimicrobial capability of non-chemically altered chitosan as an alternative to conventional antimicrobials used in oral infection treatment. Furthermore, the mechanism of action of chitosan had to be investigated. High and low molecular weight (H/LMW) chitosan showed antimicrobial activities for all tested bacteria. The following bacteria were studied: anaerobic bacteria (who require oxygen) and pathogens (who cause diseases)

Conclusion: The MIC (minimum inhibitory concentration) of chitosan was between 1 and 7 mg/ml. Furthermore, chitosan showed also to be an effective bactericidal. The bactericidal effect was noted after 8 hours at the latest. The analysis of the mechanism of action showed that LMW and HMW chitosans acted upon the bacterial cell wall quickly but didn’t interact with the intracellular substances. In summary, chitosan can be described as an effective antimicrobial against anaerobic pathogenic bacteria.

Source: Elsevier B.V./SciVerse®/ScienceDirect®

The antimicrobial action of chitosan, low molar mass chitosan, and chitooligosaccharides on human colonic bacteria.

J. Simůnek, V. Brandysová, I. Koppová, J. J. Simůnek Jr.; Folia Microbiologica (Praha); April 13, 2012 (Epub ahead of print)

In der  In this study the antimicrobial in vitro effect of different chitosans, especially chitosan oligosaccharides (COS) and LMW chitosans, was analysed regarding 7 representative anaerobic bacteria:

• Clostridium paraputrificum
• Clostridium beijerinckii,
• Roseburia intestinalis,
• Bacteroides vulgatus,
• Bacteriodes thetaiotaomicron,
• Faecalibacterium prausnitzii and
• Blautia coccoides.

The following chitosans were used to analyse the antimicrobial effect with regard to the mentioned bacteria strains:

• 0,25 and 0,5% COS (2, 3 and 6 kDa),
• 0,05% LMW chitosan (10 and 16 kDa) and
• 0,025 and 0,1% chitosan in vitro.

Conclusion: In comparison to control strains, the growth rate of all bacteria strains decreased by using COS and LMW chitosan in higher concentrations.
The most effective antimicrobial action was found in LMW chitosan with 16 kDa. However, COS with a MW of 2 and 3 kDa showed weak antimicrobial activity.

Source: National Center for Biotechnology Information