AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP13
Controlled Release of Calixarenes from Chitosan Hydrogel Coated Polymeric Surfaces as Antimicrobial Treatment of Staphylococcal Infections

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: R. Canteri, ITC-irst, Italy
Authors: M. Vinante, ITC-irst, Italy
C. Pederzolli, ITC-irst, Italy
L. Pasquardini, ITC-irst, Italy
L. Lunelli, ITC-irst, Italy
R. Canteri, ITC-irst, Italy
M. Anderle, ITC-irst, Italy
C. Potrich, CNR ITC, Italy
G. Viero, CNR ITC, Italy
M. Dalla Serra, CNR ITC, Italy
G. Prevost, Institut de Bactériologie de la Faculté de Médecine, France
O. Joubert, Institut de Bactériologie de la Faculté de Médecine, France
Correspondent: Click to Email
The proliferation of pathogenic microorganisms on biomaterial surfaces is one of the most widespread causes of failure of biomedical devices such as catheters, medical implants, vascular graft and joint prostheses. Staphylococcus species (e.g. aureus and epidermidis) are one of the major pathogens isolated in hospitals and are responsible for numerous nosocomial infections. Common virulence factors of these pathogenic staphylococcal strains are a group of secreted leucotoxins, which belong to the family of @beta@-barrel pore-forming toxins. They form poorly selective holes into the membrane of attacked cells, causing their lysis. We developed a local drug delivery system composed of chitosan hydrogel deposited on polymeric surfaces and loaded with hydrophilic agents, calixarenes. These molecules have been demonstrated to have an inhibitory effect on leucotoxins during pore-formation (reduction of 50% of hemolytic activity of 12 nM HlgA/HlgB on HRBC using 6 µmM of 4-sulfonic-calix(6)arene). Two different strategies of hydrogel formation are evaluated, one based upon ionic interactions between positively charged groups of chitosan chains and negative charges of calixarene molecules; the latter utilizing an homofunctional derivative polyethylene glycole as cross-linking agent (e.g. ButyrALD-PEG-ButyrALD) in order to form a permanent network with enhanced mechanical properties. These two kinds of interactions were also employed to stabilize the hydrogel film to the substrate. Data on the physical-chemical and morphological properties of the chitosan deposited hydrogel and the kinetics of calixarene release will be presented. @FootnoteText@ @footnote 1@Work supported by the P.A.T. Trento- Italy- Fondo Unico (project StaWars).