Abstract: The aim of this study is to prepare and characterize a bioactive and biodegradable composite scaffold of polylactic acid/wollastonite (PLA-W). Wollastonite nanobioceramic was synthesized by sol-gel method. The studied scaffolds were 3D printed with 0, 10, 20 and 30 wt% wollastonite by melt-blown 3D printer. X-ray diffraction (XRD) technique was used to confirm the presence of desired phases in the powder composition and scaffolds. Scanning electron microscope (SEM) was used to examine the shape and distribution of porosity in the scaffolds. Compression test was also used to eva‎luate the mechanical properties of the fabricated scaffolds. Water contact angle measuring device was used to examine the hydrophilicity of the scaffolds. In order to investigate the bioactive properties, the scaffolds were immersed in simulated body fluid (SBF) for 1 and 4 weeks. The germination and growth of hydroxyapatite on the surface of the scaffolds were examined by scanning electron microscopy. In order to investigate the biodegradability properties, the scaffolds were immersed in phosphate buffered saline (PBS) for 1, 2, 3 and 4 weeks and the weight changes were measured. The non-cytotoxicity of the scaffolds was investigated using the MTT assay. The cell viability was investigated by the Depi staining assay and studied using scanning electron microscopy images. The compressive strength of the scaffolds increased from 27.3 ± 2.3 MPa to 68.4 ± 4.1 MPa by adding laustenite to polylactic acid. The water contact angle decreased from o110 in the pure polylactic acid scaffold to o83 in the scaffold containing 30% w/w austenite. The formation of hydroxyapatite on the surface of the scaffolds confirmed the bioactivity of the fabricated nanocomposite, and the results showed that over time, the formed hydroxyapatites multiplied and grew. Immersion of the scaffolds in PBS solution showed that with increasing the percentage of bioceramic w/w austenite in the prepared scaffolds, the degradability of the scaffolds increased, and this degradation rate after 28 days of immersion was reported to be 1.57% in the pure sample and 2.87% in the sample containing 30% w/w austenite. The results of the MTT test related to the cultivation of MG-63 osteoblast cells on the scaffolds confirmed the lack of cell toxicity. It should be noted that higher amounts of wollastonite reduced the printability of the scaffolds and the porosity rate, such that this porosity rate decreased from 44% in the pure sample to 40% in the composite sample containing 30% wollastonite. The results of the tests conducted introduced the biodegradable and bioactive polylactic acid/wollastonite nanocomposite scaffold with 30% wollastonite as the optimal composition. The results of this study showed that biodegradable and bioactive polylactic acid/wollastonite nanocomposite scaffolds can be a suitable option for use in bone tissue engineering.

محمد خدائي , حامد جعفري

مهدي رفيعائي , رحمت اله عمادي