Mimicking Radial Porosity Gradient of Bone Structure Using Bioprinting and Controlled Release of Dexamethasone

سال انتشار: 1397
نوع سند: مقاله کنفرانسی
زبان: انگلیسی
مشاهده: 421

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شناسه ملی سند علمی:

NSCMRMED03_231

تاریخ نمایه سازی: 30 دی 1397

چکیده مقاله:

Background and Aim: The number of bone disorders has grown dramatically due to numerous reasons including aging and obesity.Bone tissue engineering has been considered as a promising methodto overcome limitations of conventional treatment procedures of bonedamages.Methods: Here, by means of PioneerX4 bioprinter, a bone scaffold hasbeen fabricated with radial porosity gradient. PioneerX4 is a homemadeand the first commercial Iranian 3D bioprinter that builds up 3Dconstructs by coordinating the motion of a print module. This deviceis able to print up to four different bio-inks including in each station.The aforementioned radial gradient porosity not only mimics the bone structure but also leads to cell differentiation. In this study, a custom-builtPCL bio-ink is coupled with alginate hydrogel as inks for the printingprocess. The PCL bio-ink is used as structural material and as a bioactivebio-ink, alginate is printed between them. Furthermore, dexamethasonemixed with alginate hydrogel to both induce cell differentiation andsuppressing inflammatory responses.Results: SEM images show radial porosity gradient design and proveprinting accuracy. The diameter of PCL and alginate strands varies in therange of 285 μm and 432 μm. The scaffold consists of three regional partsdistinguished by different porosities including 66.8%, 58.8%, and 25.9%from the inner part to the outer, respectively. The compressive modulusof printed PCL bio-ink scaffold is about 19.2±2.2 MPa. Hydroxyapatitesnanoparticles (HA NPs) were prepared using the chemical wet methodand used as carriers for sustained releasing of dexamethasone.Dexamethasone loaded HA NPs were mixed with alginate hydrogel toboth induce cell differentiation and suppressing inflammatory responsesafter surgery. The sustained release of dexamethasone lasts more than3 weeks. Finally, after 1 month most of the alginate degraded and thescaffold degradation reached 40.8%.Conclusion: Bioprinting is not only a novel method for scaffold fabricationbut also it is more alluring for bone tissue engineering due to its controlof pore interconnectivity and porosity gradient. Both dexamethasone andhydroxyapatite stimulate bone regeneration leading to accelerating boneformation.

نویسندگان

Majid Hajihosseinali

Mechanical Engineering, Sharif University of Technology, Tehran, Iran

Mohammad Hasan Ansarizadeh

Chemical & Petroleum Engineering, Sharif University of Technology, Tehran, Iran