Surface entrapment of hydroxyapatite on ۳D printed polylactic acid interference screws for biomedical application

Fixation of the biological graft by interference screws is currently a standard procedure in the treatment of the anterior cruciate ligament. The purpose of this research is to design and manufacture of polylactic acid (PLA) interference screw by fused deposition modeling (FDM) method and its surface modification with hydroxyapatite as a bioactive and hydrophilic material. For this purpose, chitosan solution (۵% wt.) was prepared in ۰.۱ M acetic acid and ۱% by weight hydroxyapatite was added to the above solution to obtain a milky colored solution. Then the porous PLA scaffolds were immersed in it. The morphology and microstructure of the surface of the scaffolds before and after immersion in a solution similar to body fluids were examined with a scanning electron microscope. The amount of hydrophilicity of the surface after coating was obtained by measuring the contact angle. The results of this research show that after ۴ weeks of immersing the sample in the simulated body solution, a layer with spherical and needle-shaped hydroxyapatite morphology was formed on the surface of the coated scaffold. This indicates a very good bioactivity of the sample. Also, reducing the contact angle in samples containing hydroxyapatite causes more cells to be on the surface. Therefore, PLA scaffolds coated with hydroxyapatite will have a suitable bioactivity for the growth and proliferation of cells and can help speed up the treatment process.

کلیدواژه ها:

Interference screws ، Polylactic acid ، Fused deposition modeling ، Hydroxyapatite