Growth modulation of fibroblasts by chitosan-polyvinyl pyrrolidone hydrogel: implications for wound management?

Wounds in adults and fetuses differ in their healing ability with respect to scar formation. In adults, wounds lacking the epidermis exhibit excess collagen production and scar formation. Fibroblasts synthesize and deposit a collagen rich extracellular matrix. The early migration and proliferation of fibroblasts in the wound area is implicated in wound scarring. We have synthesized a hydrogel from chitosan-polyvinyl pyrrolidone (PVP) and examined its effect on fibroblast growth modulation in vitro. The hydrogel was found to be hydrophilic as seen from its octane contact angle (141.2+/-0.37 degrees). The hydrogel was non-toxic and biocompatible with fibroblasts and epithelial cells as confirmed by the 3(4,5-dimethylthiazolyl-2)-2, 5-diphenyl tetrazolium bromide (MTT) as-say. It showed dual properties by supporting growth of epithelial cells (SiHa) and selectively inhibiting fibro-blast (NIH3T3) growth. Growth inhibition of fibroblasts resulted from their inability to attach on to the hydrogel. These findings are supported by image analysis, which revealed a significant difference (P<0.05) between the number of fibroblasts attached to the hydrogel in tissue culture as compared to tissue culture treated polystyrene (TCPS) controls. However, no significant difference was observed (P>0.05) in the number of epithelial (SiHa) cells attached on to the hydrogel as compared to the TCPS control. Although in vivo experiments are awaited, these findings point to the possible use of chitosan-PVP hydrogels in wound-management.

A model for testing antiseptic efficacy: a preliminary study on Betadine and Germidine.

Efficacy of povidone iodine antiseptic, betadine and germidine, was tested against normal skin flora and four pathogenic bacteria namely S. aureus, S. epidermidis, E. coli and Pseudomonas aeruginosa by a new model. The study was performed on the volar surface of forearms of ten patients. First of all, the skin flora was cultured then 10(8) cu/ml of the tested organisms was applied by a cotton swab and left to dry for 1 minute before the culture was repeated. Betadine or germidine was applied over the area previously painted with the organism. The culture was taken 1 to 2 minutes thereafter. The results showed that this model was feasible and convenient. Betadine and germidine are efficacious against normal skin flora and pathogenic bacteria.

Application of betadine (povidone iodine) to infected corneal ulcer.

A new approach of touching betadine directly to infected corneal ulcers in addition to customary treatment is suggested. A report of 35 cases of infected corneal ulcers and keratitis where it was done is studied.