Silver Ion-releasing Dressing (CONTREET) Does Not Disturb Angiogenesis and Microvascularization In Vivo

This study examined the effects of silver-releasing wound dressing on angiogenesis and microvascularization in vivo. Implants from silver-releasing and silver-free dressings were placed into dorsal skinfold chambers of BALB/c mice. A total of 30 animals (10 implants per group) were observed. Group 1 was treated with Contreet® (Coloplast, Holtedam, Denmark). Group 2 and Group 3 were primed with Biatain™ (Coloplast, Holtedam, Denmark) and SeaSorb Soft® (Coloplast, Holtedam, Denmark). Visualization of angiogenesis and quantification of functional vessel density (FVD) was performed using intravital fluorescence microscopy (IFM). Functional vessel density served as the parameter for vascularization. Functional vessel density was measured on Day 3, 7, and 12 after implantation. Intravital fluorescence microscopy revealed constant development of a sufficient network of perfused microvessels surrounding the silver-based implants. Group 1 showed a stronger morphological alteration of microvessel network at the border zone at Day 3 and even more so at Day 7, compared to the silver-free groups. Reinforced dilatation, elongation, and torsion of capillaries with progressive growth of perfused preliminary stages of new blood vessels were observed for silver-based implants. Border zone FVD of silver-based implants at Day 3 (257.1 ± 33.9 mm/mm2) was significantly increased compared to Group 2 (230.9 ± 31.3) and Group 3 (210.2 ± 35.7). At Day 7, the FVD in Group 1 was still significantly higher as measured in Group 3 (265.9 ± 30.7 versus 219.7 ± 42.6). However, no significant difference between Groups 1 and 2 at Day 7 (265.9 ± 30.7 versus 269.4 ± 31.9) and at Day 12 (258.7 ± 38.1 versus 268.3 ± 39.0) remained. In conclusion, the silver-based implants did not show any anti-angiogenic effects when compared to the silver-free implants.