Infected wound model development of an in vitro biomaterial-protected wound infection model to study microbial activity and antimicrobial treatment through microdialysis.
OBJECTIVE
Skin injuries provide a favorable environment for microbial infection if left untreated. This is problematic especially in nosocomial situations having a high prevalence of Staphylococcus aureus that can cause suppuration of wounds, systemic disease, and toxic shock. The objective of this investigation was to use a wound model system to study the interactions between microbial activity, host tissue, therapeutic treatments, and wound biomaterials.


METHODS
An in vitro wound model was developed using Sykes-Moore chambers filled with 1 of 2 biomaterials used for wound treatment (1% alginate and dialyzed HyFil hydrogel (B. Braun Medical, Inc, Bethlehem, Pennsylvania) and seeded with fibroblasts. The chambers were inoculated with S aureus, and half were later treated with antibiotics through in situ microdialysis tubing.


METHODS
The chambers were monitored by obtaining fluid samples and biomaterial samples at specific time intervals (0, 2, 8, and 24 hours) and were analyzed for (1) S aureus protein A (SPA) concentration, (2) viable S aureus numbers, and (3) fibroblast numbers and viability. Chambers containing each biomaterial with and without antibiotics were compared to controls.


RESULTS
There was an inverse relationship between postinfection S aureus numbers and fibroblast viability. S aureus numbers were usually consistent with SPA concentration, which may have been underestimated because of SPA interactions with the biomaterials.


CONCLUSIONS
This wound model may be useful to gain an understanding about the interactions between microbial activity, host tissue, therapeutic treatments, and wound biomaterials. Hypotheses about wound treatments derived by means of this model may direct future in vivo studies.
Giannini
Gina T
GT
Department of Biological Sciences, San Jose State University, San Jose, California, USA.
Boothby
John T
JT
Sabelman
Eric E
EE
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D058491:Bacterial Load; D001672:Biocompatible Materials; D002452:Cell Count; D002470:Cell Survival; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D017551:Microdialysis / Q000295:instrumentation; D008954:Models, Biological; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000517:prevention & control*; D013205:Staphylococcal Protein A / Q000032:analysis; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013997:Time Factors; D014946:Wound Infection / Q000382:microbiology*
D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D013205:Staphylococcal Protein A