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Cyclodextrins (CDs) are able to form inclusion complexes with other molecules, thereby, protecting these guest molecules from degradation, enhancing their biocompatibility or influencing their physiological distribution while retaining their activity. Here, antibacterial effects of CD-complexes with the antiseptics chlorhexidine diacetate (CHX), iodine (IOD) and polihexanide (PHMB) were determined using two different in vitro methods, microplate laser nephelometry and an ATP bioluminescence assay. Laser nephelometry is a direct method for monitoring and evaluating growth of micro-organisms by measurement of the turbidity of the solution. In contrast, the ATP bioluminescence assay determines specifically the amount of metabolic active bacterial cells. The antibacterial effects of CD-antiseptics-complexes were examined for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis and the results of both methods were compared in respect of calculated means of half maximal inhibitory concentrations (IC50) and statistical evaluated Pearson's correlation coefficients (r). It could be demonstrated that both methods showed a high comparability although they differ in the parameters tested. This study revealed that CD-complexes with CHX and PHMB were most effective against E. coli and the tested staphylococci. While CD-IOD-complexes obtained high activity against K. pneumoniae, P. aeruginosa was distinctly more resistant compared to the other bacteria.

Hemocompatibility of aqueous solutions of antimicrobial 6-deoxy-6-aminoethyleneamino (AEA) cellulose with different degrees of substitution (DS, 0.54-0.92) was investigated in vitro. The AEA cellulose derivatives were synthesized by tosylation of cellulose and subsequent nucleophilic substitution with 1,2-diaminoethane. The structure was confirmed by elemental analysis as well as by FTIR and NMR spectroscopies. Markers for coagulation (thrombin generation, aPTT, PT, blood clotting, thrombocyte activation) and membrane integrity (hemolysis) were measured in human whole blood, human platelet-rich plasma, human pooled plasma, and erythrocytes suspension. AEA cellulose with a low DS of 0.54 showed the highest hemocompatibility in vitro, suggesting the possibility of biomedical applications.

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Functionalized textiles can be used in wound management to reduce the microbial burden in the wound area, to prevent wound infections, and to avoid cross-contamination between patients. In the present study, a comprehensive in vitro approach to enable the assessment of antibacterial activity of functionalized textiles and cytotoxicity of cyclodextrin (CD)-complexes with chlorhexidine diacetate (CHX), iodine (IOD), and polihexanide (PHMB) is suggested to evaluate their properties for supporting optimal conditions for wound healing. For all β-CD-antiseptic functionalized cotton samples a strong antibacterial effect on the Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis as well as on the Gram-negative bacteria Klebsiella pneumoniae and Escherichia coli was proven. In addition, β-CD-CHX and β-CD-PHMB were effective against the yeast Candida albicans. The growth of Pseudomonas aeruginosa could be reduced significantly by β-CD-IOD and β-CD-PHMB. The established comprehensive testing system for determination of biocompatibility on human HaCaT keratinocytes is suitable for obtaining robust data on cell viability, cytotoxicity and mode of cell death of the β-CD-antiseptic-complexes. The promising results of the high antimicrobial activity of these functionalized textiles show the high potential of such materials in medical applications.