UiO-66 Metal-organic Framework (MOF) as an Osteogenic Stimulant in the Poly-3-hydroxybutyrate-zein/UiO-66 Electrospun Composite Scaffold for Bone Tissue Engineering Applications

Abstract

Metal-organic frameworks have recently become popular in biomedical applications due to their high surface areas, porosity, suitable mechanical properties, controlled degradability, and selective compositions. Among them, UiO-66 is particularly noteworthy for its exceptional stability, biodegradability, low toxicity, and osteogenic properties. Herein, UiO-66 was synthesized via a solvothermal method and characterized employing FTIR, XRD, FESEM, and TEM analyses. Subsequently, poly-3-hydroxybutyrate-zein/UiO-66 electrospun composite scaffolds were fabricated. Regarding the SEM, mechanical analyses, and water contact angle results, the scaffold containing 2 wt UiO-66 exhibited the optimum characteristic. EDS and TEM examinations confirmed UiO-66's presence and distribution, TGA validated its claimed amount in the scaffold, and FTIR revealed the possible interactions between ingredients. Incorporating 2 wt UiO-66 reduced the fiber diameter and water contact angle by about 54 nm and 20 degrees, respectively, while increasing surface roughness and crystallinity. UiO-66 significantly enhanced ultimate tensile stress and Young's modulus by approximately 90 and 101, respectively. It also boosted the biomineralization of the scaffold and hastened the degradation rate. Eventually, adding UiO-66 led to noticeable increases in viability, proliferation, attachment, ALP activity, and ECM mineralization, as well as upregulation of COL Iota, RUNX2, and OCN genes of MG-63 cells seeded on the scaffolds. In conclusion, incorporating UiO-66 not only reinforced the composite scaffold but also stimulated osteogenesis, making it an advantageous candidate for bone tissue engineering applications.