RESUMEN
Additive manufacturing of polymers is gaining momentum in health care industries by providing rapid 3D printing of customizable designs. Yet, little is explored about the cytotoxicity of leachable toxins that the 3D printing process introduced into the final product. We studied three printable materials, which have various mechanical properties and are widely used in stereolithography 3D printing. We evaluated the cytotoxicity of these materials through exposing two fibroblast cell lines (human and mouse derived) to the 3D-printed parts, using overlay indirect contact assays. All the 3D-printed parts were measured toxic to the cells in a leachable manner, with flexible materials more toxic than rigid materials. Furthermore, we attempted to reduce the toxicity of the 3D-printed material by employing three treatment methods (further curing, passivation coating, and Soxhlet solvent extraction). The Soxhlet solvent extraction method was the most effective in removing the leachable toxins, resulting in the eradication of the material's toxicity. Passivation coating and further curing showed moderate and little detoxification, respectively. Additionally, mechanical testing of the materials treated with extraction methods revealed no significant impacts on its mechanical performances. As leachable toxins are broadly present in 3D-printed polymers, our cytotoxicity evaluation and reduction methods could aid in extending the selections of biocompatible materials and pave the way for the translational use of 3D printing.
RESUMEN
Background: Submicron particles (SMPs), as novel bionanomaterials, offer complementary benefits to their conventional nano-counterparts. Aim: To explore zinc oxide (ZnO) SMPs' bioimaging and anticancer potentials. Materials & methods: ZnO SMPs were synthesized into two shapes. Fluorescent spectrum and microscopy were studied for the bioimaging property. Wound healing and Live/Dead assays of glioblastoma cells were characterized for anticancer activities. Results: ZnO SMPs exhibited a high quantum yield (49%) with stable orange fluorescence emission. Both morphologies (most significant in the rod shape) showed tumor-selective properties in cytotoxicity, inhibition to cell migration and attenuating the cancer-upregulated genes. The tumor selectivity was attributed to particle degradation and surface properties on pH dependency. Conclusion: The authors propose that ZnO SMPs could be a promising anticancer drug with tunable, morphology-dependent properties for bioimaging and controlled release.
Submicron particles (SMPs) are a novel nanomaterial whose total size is microscale (around one-millionth of a meter), but at least one dimension is nanoscale (around one-billionth of a meter). Their combined micro- and nanoscale properties are complementary, which can be an improvement on their conventional nano-counterparts. The aim of this study was to explore the bioimaging and anticancer properties of zinc oxide (ZnO) SMPs. ZnO SMPs were synthesized in two shapes: rod-shaped and flower-shaped. The fluorescence spectra and microscopy images were studied to investigate their potential for imaging applications, and wound healing and viability assays of glioblastoma cells were used to characterize anticancer activity. ZnO SMPs exhibited strong and stable orange fluorescence emission. Both shapes of ZnO SMPs showed tumor-selective toxicity, inhibition to cell migration and attenuating the cancer-upregulated genes; however, these effects were more significant for the rod-shaped particles. The tumor selectivity was attributed to pH-dependent particle degradation related to surface properties. The authors therefore propose that ZnO SMPs could be a promising anticancer drug with tunable, morphology-dependent properties for bioimaging and controlled release.
