Characterization and In Vitro and In Vivo Assessment of a Novel Cellulose Acetate-Coated Mg-Based Alloy for Orthopedic Applications

Abstract

Despite their good biocompatibility and adequate mechanical behavior, the main limitation of Mg alloys might be their high degradation rates in a physiological environment. In this study, a novel Mg-based alloy exhibiting an elastic modulus E = 42 GPa, Mg-1Ca-0.2Mn-0.6Zr, was synthesized and thermo-mechanically processed. In order to improve its performance as a temporary bone implant, a coating based on cellulose acetate (CA) was realized by using the dipping method. The formation of the polymer coating was demonstrated by FT-IR, XPS, SEM and corrosion behavior comparative analyses of both uncoated and CA-coated alloys. The potentiodynamic polarization test revealed that the CA coating significantly improved the corrosion resistance of the Mg alloy. Using a series of in vitro and in vivo experiments, the biocompatibility of both groups of biomaterials was assessed. In vitro experiments demonstrated that the media containing their extracts showed good cytocompatibility on MC3T3-E1 pre-osteoblasts in terms of cell adhesion and spreading, viability, proliferation and osteogenic differentiation. In vivo studies conducted in rats revealed that the intramedullary coated implant for fixation of femur fracture was more efficient in inducing bone regeneration than the uncoated one. In this manner, the present study suggests that the CA-coated Mg-based alloy holds promise for orthopedic aplications.

Synthesis and Characterization of PLA-Micro-structured Hydroxyapatite Composite Films

“…Our observed small differences in the thermal behavior of the obtained films can be explained by the lower percent of HA (1-4% wt. ), which is more suitable for potential application in osseointegration and is enough to influence the proliferation of pre-osteoblasts through the pores of polymeric films [5,7]. With potential application in osseointegration as films at the interface between a metallic implant and bone, porous films are preferred due to their more bioresorbable behavior under physiological conditions, with in this case the mechanical and thermal properties not being very important [8][9][10].…”

“…In this case, the membrane can be placed at the interface between a metal implant and bone. These materials aim to improve and to accelerate the integration of the metal implant into the bone [5][6][7]. Composite membranes and polymeric films based on hydroxyapatite (HA) have lately seen great development, especially due to their potential applications in orthopedics [8].…”

Evaluation of a Zn–2Ag–1.8Au–0.2V Alloy for Absorbable Biocompatible Materials

“…An appropriate degradation behavior is critical to maintain its mechanical integrity as well as the bioactivity of the implant during the whole tissue remodeling period. Regarding Mg and its alloys, the main drawback is the too-fast degradation process accompanied by the accumulation of hydrogen in the tissue, making Mg-based materials not only too insufficient to provide mechanical integrity but impeding tissue healing as well [6,7]. In contrast, Fe and its alloys degrade too slowly in vivo, leading to long-term retention in the body [8,9].…”

Nanochannelar Topography Positively Modulates Osteoblast Differentiation and Inhibits Osteoclastogenesis

“…Intracellular ALP activity in the cell lysates was measured using Alkaline Phosphatase Activity Colorimetric Assay Kit (BV-K412-500, BioVision, Milpitas, CA, USA) on the 7th and 14th day of osteoinduction [21]. The ALP activity was normalized by the total protein content determined with the Bradford reagent, according to the manufacturer's guidelines.…”