Molar-mass-dependent antibacterial activity of cationic dextran derivatives against resistant nosocomial pathogens

The rise of various multidrug-resistant bacteria has created a need for new biocompatible and biodegradable antibacterial compounds. Cationic polysaccharides are promising candidates for this role. Therefore, cationic derivatives of commercial dextrans with molar masses of 11 kDa, 76 kDa, 411 kDa, and 1500-2500 kDa and various degrees of substitution (DSQ 0.34-0.52) were prepared and their antimicrobial properties against four gram-negative nosocomial bacteria were tested. As expected, a higher DSQ led to higher efficiency. The best antimicrobial properties were found for derivatives of 411 kDa, followed by 76 kDa and 1500-2000 kDa dex-trans. This indicates that there is a certain optimum molar mass with the best antimicrobial properties. However, as molar mass increased, the biocompatibility of cationic dextran steadily decreased, with increased hemag-glutination and toxicity being seen for human cells. The derivatives of 76 kDa dextran with higher DSQ (0.40-0.52) were the best antimicrobial agents suitable for further clinical testing.

Automated summary

The rise of multidrug-resistant bacteria has increased the demand for new biocompatible and biodegradable antibacterial compounds. Cationic polysaccharides, such as derivatives of commercial dextrans, show promising antimicrobial properties. The study found that derivatives with higher degree of substitution and varying molar masses had better antimicrobial efficiency. However, as the molar mass increased, the biocompatibility of the cationic dextran decreased, showing hemagglutination and toxicity to human cells. The derivatives of 76 kDa dextran with higher degree of substitution were identified as the best antimicrobial agents for further clinical testing.