Effects of microsize on the biocompatibility of UiO67 from protein-adsorption behavior, hemocompatibility, and histological toxicity

The biocompatibility of metal-organic frameworks (MOFs) is necessary to humans but is far from being sufficiently addressed. This study focused on the effects of microsize on the biocompatibility of MOFs by selecting UiO67 with micron and submicron size as the MOFs models. Under the dose metric of surface area, the binding constant between UiO67 and human serum albumin (HSA) gradually increased with increased UiO67 size. Submicron UiO67 induced stronger conformational transformation and more greatly affected the protein surface hydrophobicity than micron UiO67. Micron UiO67 also inhibited the esterase-like activity of HSA through competitive inhibition mechanism, whereas submicron UiO67 inhibited it through noncompetitive inhibition mechanism. The size of UiO67 had little effect on hemocompatibility. A smaller size of UiO67, corresponded with a higher IC50 value for 293 T and LO2 cells, and the adsorption of HSA can effectively improve cytotoxicity. In vivo toxicity evaluations revealed that all UiO67 did not cause obvious distortion of organs, and they were metabolized primarily in the kidney. These results provided useful information about the toxicity of MOFs and experimental references for the development of MOFs-based engineering materials.