Silver Nylon Research Articles

Enhanced Survival of Autoepidermal-Allodermal Composite Grafts in Allosensitized Animals by Use of Silver-Nylon Dressings and Direct Current

Observe the effect of silver-nylon (SN) dressing and direct electric current on healing of meshed autoepidermal/allodermal composite skin grafts (MCSGs) in allosensitized rats. MCSGs were placed on experimental animals 28 to 30 days after placement of sensitizing allografts. MCSGs and control allografts were covered with either Vaseline gauze (VG) or SN; direct current, 40 microA, was applied for 5 days to some of the SN-dressed wounds (SNDCs). Second set rejection of MCSG was not observed. SN- and SNDC-treated grafts showed expansion of the meshed autoepidermis with complete epithelialization within 3 weeks. VG-covered wounds developed areas of open granulation and were not completely epithelialized at 3 months. Both SN and SNDC reduced wound contraction when compared to VG (SN versus VG p < 0.02, SNDC versus VG p < 0.008). MCSG was found to be of low alloantigenicity in that it did not induce second set rejection of subsequent skin allograft. SN dressings enhanced survival of meshed composite skin grafts.

The burn wound: Effect of silver nylon dressing and DC

The burn wound: Effect of silver nylon dressing and DC

Multiple Graft Harvestings from Deep Partial-thickness Scald Wounds Healed under the Influence of Weak Direct Current

The time required for wound healing, contraction, and hypertrophic scarring often limit the use of deep partial-thickness burn wounds as donor sites for split-thickness grafts. We have examined the effects of weak direct current and silver nylon dressings on the healing of partial-thickness scald burns, split-thickness grafts taken from these wounds when healed, and the resulting donor sites in a guinea pig model. Dorsal scald wounds treated with weak direct current reepithealized by 12 days postinjury. Split-thickness grafts taken from healed scald wounds showed more rapid revascularization with direct current treatment than did control grafts. Grafts and donor sites treated with direct current showed more rapid reepithelialization, decreased contraction, improved hair survival, and decreased dermal fibrosis when compared to controls not treated with direct current. Only donor wounds treated with weak direct current were reusable as donor sites.

Therapeutic effects of silver nylon dressings with weak direct current on Pseudomonas aeruginosa-infected burn wounds.

The therapeutic and prophylactic effects of nylon dressings coated with metallic silver in a direct current circuit have been examined in a rat model of fatal burn wound sepsis. Male Sprague-Dawley rats weighing 325 +/- 25 grams with 20% full-thickness scald injuries were used. Therapeutic effects were examined at 4 or 24 hours after surface inoculation with a lethal dose of Pseudomonas aeruginosa (Strain 59-1244). When used as a surface anode with an implanted silver needle cathode, the silver nylon was therapeutic at currents between 0.4 and 40 microA when applied at either test time and continued for 5 days (p less than 0.001). When used as a cathode, silver nylon was not effective. Nylon cloth without a silver metal coating was not effective without applied current or when used as an anode. Silver nylon dressings placed at 4 hours after inoculation but without applied current showed significant effectiveness (p less than 0.01). This effect, however, was significantly less than that seen with silver nylon used as an anode (p less than 0.001). Barrier prophylactic effects were examined by placing silver nylon or uncoated nylon on burn wounds before inoculation with Pseudomonas aeruginosa. The uncoated nylon had no barrier effect. Silver nylon was found protective but applied current was not required for significant (p less than 0.001) barrier effect. These results indicate silver nylon dressings may be a valuable antimicrobial burn wound covering device.

Silver Nylon Cloth

The topical agents used in burn care today, although beneficial, do have limitations, the most important of which is the failure to prevent or treat burn wound infections in patients with extensive injuries. Therefore, we evaluated the antimicrobial activity of two silver nylon fabrics (SN and HRS) on the growth of S. aureus, P. aeruginosa, and C. albicans. The theoretical advantages of these nylon fabrics over presently available silver compounds is their ability to continuously release silver ions into the burn wound as long as the material is in contact with the wound. Additionally, the release of silver from these fabrics can be augmented electrolytically. The results of these experiments indicated that both materials were microbicidal in vitro for all three test organisms. Furthermore, the antimicrobial activity could be significantly augmented by passing a weak DC current through the material, which increased the rate of release of silver ions from the fabrics. In vivo, HRS was as effective as silver sulfadiazine in preventing colonization of the burn wound. The use of silver nylon fabrics thus appears to be a promising way of delivering large quantities of silver ions into the burn wound without the potential side effects of a carrier molecule or cream.

Silver-nylon: a new antimicrobial agent.

The potential effectiveness of a silver nylon (SN) fabric as an antimicrobial agent was evaluated in a series of in vitro experiments. The results indicated that silver ions from the SN fabric penetrated 2 mm of agar and killed a challenge of 6.9 X 10(7) Pseudomonas aeruginosa, 4.1 X 10(7) Staphylococcus aureus, and 1.4 X 10(7) Candida albicans organisms per cm2 of SN fabric after 24 h of incubation at 37 degrees C. To determine some of the microbicidal limits of the SN, the distance between the SN fabric and the microbial challenge was increased. Increasing the height of the agar column overlying the SN fabric diminished the inhibitory effect of SN on microbial growth. For each increase in agar height of 2 mm, up to a total height of 8 mm, the effectiveness of SN to inhibit microbial growth decreased by a factor of 10. This distance-related decrease in the microbicidal ability of SN could be overcome by placing the SN fabric in contact with the agar column for 24 to 72 h before microbial challenge. On the basis of these experiments, it appears that SN is an effective antimicrobial agent, although further work must be performed before it is applied clinically.