In vitro and ex vivo investigation of intralesional sodium thiosulfate as a reversal agent for calcium hydroxylapatite soft tissue filler: Dataset
Description
In this study, we developed both in vitro and human tissue ex vivo models to compare the effect of sodium thiosulfate (STS) versus saline on calcium hydroxylapatite (CaHA) size. In the first phase of the experiment, an in vitro model was developed to measure CaHA microsphere size following exposure to STS or saline under room temperature or simulated physiologic (37°C, 5% CO2) conditions. Two identical microplates were prepared containing three samples of each CaHA:STS dilution (1:4, 1:2, 1:1, 2:1, 4:1) and one sample of each CaHA:saline dilution (1:4, 1:2, 1:1, 2:1, 4:1). After 24 hours, three samples were obtained from each well and spread across a glass microscope slide. Each slide was visualized under a microscope at 5x magnification. Three images were taken of the CaHA microspheres on each slide, for a total of 27 images per STS experimental group and 3 images per saline experimental group. Following image acquisition, microsphere diameter (micrometer) was calculated using Image J (version 1.53k, National Institutes of Health, Bethesda, MD). In the second phase of the experiment, an ex vivo human skin model was used to study CaHA microsphere dispersion following exposure to STS or saline. Dog ear tissue samples were injected with equivolemic amounts of STS or saline. Skin samples were then placed in RPMI tissue culture medium at 7.4 pH to maintain tissue viability and incubated for 24 hours at 37°C and 5% CO2. Following incubation, samples were fixed in formalin, embedded en-face and sectioned to create 4 μm thick sections with 30 μm intervals between sections. Eight sections were analyzed for each tissue sample. Dispersion of microspheres was assessed by measuring the distance from the injection point at the center of the sample to the maximum radial point at which microspheres were identified. Measurements were obtained using Olympus CellSens Software and a digital micrometer (Olympus Corporation, Tokyo, Japan). A maximum dispersion distance was recorded from each section, yielding up to 8 values per sample.