Bioactive Response Of Pmma Coating Obtained By Electrospinning On Iso5832-9 And Ti6al4v Biomaterials

Degenerative diseases, such as osteoarthritis, osteoporosis and accidents can cause hip problems and injuries leading to a necessary hip prosthetic replacement. Acetabular and femoral prosthesis parts, consisting of special alloys of steel and titanium, are fixed to the bones using orthopedic cement based on poly(methyl methacrylate) (PMMA). With aim of improving implant material properties in terms of compatibility with the human body, were evaluated the bioactive responses of ISO 5832-9 steel and Ti6Al4V alloy coated with electrospun PMMA nanofibers. The electrospinning technique is widely used due to the possibility of easily producing fibers within nano or micrometric scale using a low cost, simple experimental apparatus that allows large-scale production. In this work the metallic substrates were submitted to surface pretreatments with sanding alone or in combination with acid etching. After deposition by electrospinning, the surfaces were characterized morphologically, chemically, and for roughness. PMMA fibers were obtained, with nanometric diameter, forming a uniform and homogeneous layer over both metal sample surfaces without appreciable differences in adhesion. The sanded surface, being a one-step process, was chosen for the next step. Fibroblasts were grown on the sample surfaces, for seven days, to determine biocompatibility. Electrospinning Induced Surface Activation (EISA) was used to incorporate hydroxyl radicals into the PMMA chain to produce hydroxylated PMMA, that was later redissolved and electrospun into nanofibers. Both samples (PMMA and PMMA-OH nanofibers) resulted in good cell adhesion properties. However, a denser cell monolayer was observed on the hydroxyl-terminated sample, indicating better cell-material interaction. Hydroxyl (OH) functionalized molecules can regulate cell behavior acting as a linker capable of reacting with proteins, thus accelerating cell growth, migration, differentiation, synthesis of extracellular matrix components, and tissue morphogenesis. By a simple two-step methodology it was possible to obtain electrospun hydroxyl functionalized bioactive PMMA nanofibers deposited on metallic implant samples with an increased cell response.