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Objective: A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs)., Methods: The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing., Results: The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity., Significance: The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration., (Copyright © 2017. Published by Elsevier Ltd.)

In this research, the three dimensional porous scaffolds made of a polycaprolactone (PCL) microsphere/TiO 2 nanotube (TNT) composite was fabricated and evaluated for potential bone substitute applications. We used a microsphere sintering method to produce three dimensional PCL microsphere/TNT composite scaffolds. The mechanical properties of composite scaffolds were regulated by varying parameters, such as sintering time, microsphere diameter range size and PCL/TNT ratio. The obtained results ascertained that the PCL/TNT (0.5wt%) scaffold sintered at 60°C for 90min had the most optimal mechanical properties and an appropriate pore structure for bone tissue engineering applications. The average pore size and total porosity percentage increased after increasing the microsphere diameter range for PCL and PCL/TNT (0.5wt%) scaffolds. The degradation rate was relatively high in PCL/TNT (0.5wt%) composites compared to pure PCL when the samples were placed in the simulated body fluid (SBF) for 6weeks. Also, the compressive strength and modulus of PCL and PCL/TNT (0.5wt%) composite scaffolds decreased during the 6weeks of storage in SBF. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay and alkaline phosphates (ALP) activity results demonstrated that a generally increasing trend in cell viability was observed for PCL/TNT (0.5wt%) scaffold sintered at 60°C for 90min compared to the control group. Eventually, the quantitative RT-PCR data provided the evidence that the PCL scaffold containing TiO 2 nanotube constitutes a good substrate for cell differentiation leading to ECM mineralization., (Copyright © 2016. Published by Elsevier B.V.)

Objectives This paper describes the fabrication of a new porous 3D-printed scaffold composed of polycaprolactone (PCL) and polyether-ether ketone (PEEK) micro-particles for bone tissue engineering (BTE) applications. Methods In order to improve the compatibility of the reinforcing PEEK powder with polycaprolactone, the PEEK powder was surface-modified by an amino-silane coupling agent. After modification, Fourier-transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC) were used to investigate the chemical reaction between PEEK and silane coupling agent. In order to increase the compressive modulus of the 3D printed PCL scaffold, 10% silane-modified PEEK was incorporated into the PCL polymeric matrix. Scanning electron microscopy (SEM) was used for cell morphology and attachment evaluation. Results The results indicated that the silane coupling agent was successfully grafted onto the particle surface. The compressive modulus of PCL scaffold increased by incorporating the silane-modified PEEK, despite having higher porosity, compared with the pure PCL scaffolds. Addition of amino-silane had a positive impact on cell response, and that surface modification led to improved particle dispersion. Conclusion In conclusion, it seems that the incorporation of surface-modified PEEK micro-particles into the PCL porous scaffold could enhance its mechanical properties, and may be applicable for the management of large bone defects. [ABSTRACT FROM AUTHOR]

The objective of this research was to study the degradation and biological characteristics of the three-dimensional porous composite scaffold made of poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite microsphere using sintering method for potential bone tissue engineering. Our previous experimental results demonstrated that poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite composite scaffold with a ratio of 4:1 sintered at 90ºC for 2 h has the greatest mechanical properties and a proper pore structure for bone repair applications. The weight loss percentage of both poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite and poly(lactic-co-glycolic acid) scaffolds demonstrated a monotonic trend with increasing degradation time, that is, the incorporation of nano-fluorhydroxyapatite into polymeric scaffold could lead to weight loss in comparison with that of pure poly(lactic-co-glycolic acid). The pH change for composite scaffolds showed that there was a slight decrease until 2 weeks after immersion in simulated body fluid, followed by a significant increase in the pH of simulated body fluid without a scaffold at the end of immersion time. The mechanical properties of composite scaffold were higher than that of poly(lactic-co-glycolic acid) scaffold at total time of incubation in simulated body fluid; however, it should be noted that the incorporation of nano-fluorhydroxyapatite into composite scaffold leads to decline in the relatively significant mechanical strength and modulus during hydrolytic degradation. In addition, MTT assay and alkaline phosphatase activity results defined that a general trend of increasing cell viability was seen for poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite scaffold sintered by time when compared to control group. Eventually, experimental results exhibited poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite microsphere-sintered scaffold is a promising scaffold for bone repair. [ABSTRACT FROM AUTHOR]

Over the past several decades, the implementation of bioceramics in orthopedic bioengineering has become increasingly profound. The resemblance of the material to bone histomorphology makes them favorable to use in tissue engineering schemes, in addition to the evidence that they exhibit osteoconductivity and that many manifest the appropriate mechanical strength. Moreover, the strategy to use the 3D bioprinting technique holds the potential to consistently manufacture commercializable scaffolds, tailored for diverse clinical applications with physicochemical property-dependent biodegradation rates, and usher in a new era of effective hard tissue fabrication. This review is the first of its kind in that it has thoroughly compiled the most recent studies on 3D printing of bioceramic scaffolds to treat bone defects and anomalies. Manuscripts were mostly chosen from the last decade, highlighting the novelty of the approach to regenerative orthopedic bioengineering via ceramic-based 3DP technologies. Likewise, in addition to the materials perspective present in the body of this work, tissue engineering scaffold requirements were explained as well as the incorporation of drug delivery schemes for localized drug administration and cargo release rates in pre-clinical studies. [ABSTRACT FROM AUTHOR]