ساخت و مشخصه يابي داربست كامپوزيتي پلي كاپرولاكتون/نانوذرات شيشه ي زيست فعال 58S به روش چاپ سه بعدي داراي پوشش ZIF-8 براي كاربردهاي مهندسي بافت استخوان

Fabrication an‎d characterization of composite scaffold based on polycaprolactone/bioactive glass nanoparticles with ZIF-8 coating by 3D printing method for bone tissue engineering applications

نانو فناوري

Bone is the second most transplanted tissue globally, an‎d the deman‎d for it is continuously increasing. Bone tissue engineering scaffolds are developed to promote bone tissue regeneration an‎d repair critical-size defects. In this study, a composite scaffold for bone defect repair was fabricated using 3D printing. The aim of this study is to investigate the bioactivity an‎d biodegradability of the fabricated scaffolds. Also, the cellular behavior on scaffolds modified by ZIF-8, as the most well-known metal-organic framework, was investigated. First, bioactive glass (BG) of type 58S was synthesized via the sol-gel method. The synthesized powder was characterized using XRD, SEM, an‎d BET analyses. Composite scaffolds containing different weight percentages of 58S (40, 45, an‎d 50) combined with polycaprolactone (PCL) were produced using a 3D printing device. Compression mechanical testing was performed on scaffolds with various PCL an‎d 58S compositions. The optimal scaffold, with 45 wt.% 58S, demonstrated a compressive strength of 35.4 ± 0.6 MPa an‎d a compressive modulus of 0.63 ± 0.04 MPa an‎d was selec‎ted for further biological eva‎luations. Bioactivity an‎d biodegradability were assessed using SBF an‎d PBS solutions. The scaffold degradation rate was 9% over four weeks, confirming its biodegradability. SEM an‎d XRD tests also verified the formation of an apatite layer on the scaffold surface, demonstrating its bioactivity. In situ synthesis of ZIF-8 nanoparticles on the optimal scaffold was performed, an‎d the formation of this layer was confirmed using XRD an‎d EDS analyses. Biological eva‎luations, including MTT assays an‎d Phalloidin/DAPI cell staining, were conducted to assess cell attachment, proliferation, an‎d adhesion (MG-63) on scaffolds with an‎d without ZIF-8. Cellular studies confirmed the biocompatibility of both scaffold types an‎d demonstrated superior biocompatibility for scaffolds containing ZIF-8, validating them as suitable substrates for the adhesion an‎d proliferation of MG-63 osteosarcoma cells. Thus, incorporating BG into PCL an‎d fabricating 3D-printed PCL/BG scaffolds improved the compressive strength, bioactivity, an‎d biodegradability of the scaffolds. Consequently, composite PCL/BG scaffolds with a ZIF-8 nanolayer coating could serve as promising can‎didates for bone substitutes.

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