Evaluation of 3D bioprinted skin scaffolds in mice along with gold nanoparticles exposure

The progress in nanomedicine has sparked increasing concerns regarding its applications in interaction with biocompatible materials. Here, we assessed and optimized the 3D bioprinting technique by testing various printing parameters with multiple types of cells. Cell-laden scaffolds were designed, cultivated, imaged, and transplanted onto the dorsal skin of nude mice. The structure of bioprinted scaffolds retained its shape and dimensions with no cell migration between layers. Moreover, gold nanoparticles (GNPs) were intravenously administered to transplanted nude mice and aggregately deposited in the cell-laden scaffolds. Importantly, GNPs exhibited extensive accumulation in bioprinted scaffolds compared to natural skin and other organs in vivo. GNPs accumulated in the dermis of the transplanted scaffolds, while they stayed in the subcutaneous tissue of the natural skin with no permeation to the dermis, indicating a high absorption tendency of GNPs for artificial scaffolds. The results revealed the lack of similarity of the artificial skin scaffolds to natural skin, which may weaken its potential applicability as artificial skin substitutes. Furthermore, the absorption property of 3D bioprinted scaffolds suggested its potential employment as: (1) a redemption therapeutic method to absorb and excrete GNPs; (2) a strategy for targeting drug delivery of GNPs.