The effect of coating microRNA-155-5p on titanium implants on differentiation of bone marrow mesenchymal stem cells to osteoblasts

Abstract

Introduction and background:Nowadays use of implants is common for replacing of missing teeth but it does not induce bone formation actively. Therefore, research continues to find different methods to modify the implant surface to improve osseointegration. For this purpose, in the present study, an attempt has been made to design an implant coating that can meet the necessary needs. A very important factor in bioactive coatings is having osteoinductivity which micro-nanocoatings used so far lacked this factor. MicroRNAs (miR) are short RNA molecules that regulate gene expression after the mRNA transcription process. The differential expression of microRNAs during osteogenic differentiation suggests the essential role of these transcripts in bone formation. As a result, the aim of this project is to coat microRNA-155-5p on the surface of the titanium implant and to investigate its effect on the mesenchymal stem cell line of the bone marrow to increase osseointegration. Methods and materials: In the first step, microRNA-155-5p is encapsulated in carboxymethyl chitosan by in situ polymerization and the produced nanocapsules are analyzed by dynamic light scattering. In the next step, 30 titanium alloy discs with a thickness of 0.8 mm are prepared and polished by silicon carbide paper and washed with acid, ethanol, and acetone. Then chitosan is coated on titanium implants by dip coating method and the obtained product is identified and confirmed by SEM. ALP test via colorimetry was used to assess osteoblastic activity and MTT was used for biocompatibility evaluation. Results: The DLS test showed 250nm size and zeta potential of 28Mv for chitosan nanoparticles. Mean ALP index showed significant difference between study groups, The minimum and maximum amounts belong to miR and CS-miR groups. Also there was significant difference between biocompatibility of the study groups, the minimum and maximum values belong to CS-miR and miR groups. Conclusion: titanium discs with chitosan-miR coat showed great biocompatibility and increased ALP secration.