Small Animal Surgery Resident Purdue University West Lafayette, Indiana
In Vitro Elution of Silver Nanoparticles from Three Carrier Media. Peterson JL, Risselada M. Purdue University, College of Veterinary Medicine, Department of Veterinary Clinical Sciences, West Lafayette, IN.
The use of biodegradable sustained-release silver nanoparticle (AgNP) constructs has not been described as a topical treatment for multidrug-resistant infections. The objective of this study was to determine and compare the rate, pattern, and completeness of AgNP elution from three carriers in vitro. Calcium sulfate hemihydrate (CSH) beads, poloxamer 407 gel, and a gelatin sponge were used to create AgNP constructs (8500 ng AgNP/construct). All carriers were evaluated in quadruplicate (12 constructs total) and submerged in PBS at 38°C for seven days. Samples were collected at 2, 6, 12, 18, 24, 36, 48, 72, 96, 120, 144, and 168 hours. AgNP concentration was measured using inductively coupled plasma mass spectrometry and compared by repeated measures ANOVA (P < 0.05). Release of AgNPs was seen from all constructs for a minimum of 72 hours, but differed among carriers (P < 0.0001). Release was incomplete with an initial burst during the first 24 hours followed by a time dependent gradual decline in elution rate for up to 168 hours. Gel constructs released the largest quantity of AgNPs (8401.022 ng, 98.84%), followed by sponge constructs (1503.454 ng, 17.69%). Release of AgNPs from CSH bead constructs was 87.824 ng (1.03%), with no additional release after 72 hours. Main limitations of this study include those associated with use of an in vitro model to mimic a live wound bed. Sustained release of AgNPs is possible in vitro, but efficacy against bacterial infections needs to be investigated prior to clinical use.