Tissue Engineered Bone Using Polycaprolactone Scaffolds Made by Selective Laser Sintering

Abstract

Polycaprolactone is a bioresorbable polymer that has potential for tissue engineering of bone and cartilage. In this work, we report on the computational design and freeform fabrication of porous polycaprolactone scaffolds using selective laser sintering, a rapid prototyping technique. The microstructure and mechanical properties of the fabricated scaffolds were assessed and compared to designed porous architectures and computationally predicted properties. Compressive modulus and yield strength were within the lower range of reported properties for human trabecular bone. Finite element analysis showed that mechanical properties of scaffold designs and of fabricated scaffolds can be computationally predicted. Scaffolds were seeded with BMP-7 transduced fibroblasts and implanted subcutaneously in immunocompromised mice. Histological evaluation and micro-computed tomography (gCT) analysis confirmed that bone was generated in vivo. Finally, we have demonstrated the clinical application of this technology by producing a prototype mandibular condyle scaffold based on an actual pig condyle.

Micro-CT studies on 3-D bioactive glass–ceramic scaffolds for bone regeneration

“…This possibility sparks great interest for micro-CT since it allows high spatial resolution images to be generated from 10 to 1 μm, with high signal-to-noise ratio [31][32][33]. The recent use of micro-CT in scaffold research has enabled accurate morphological studies to be carried out, yielding comprehensive data sets [34][35][36][37][38][39][40][41][42]. Very promising and advanced fields of investigations can be opened by micro-CT in tissue engineering [43], but in most of the research works its use is limited to the visualization of the scaffold morphology and the determination of its porosity while the investigation of the newly formed phase is usually carried out only at the scaffold surface by SEM and X-ray diffraction [44][45].…”

Evaluation of bioprinter technologies

“…Three-dimensional printing is preferred when building engineered tissue structures due to its repeatability and high accuracy in micro-scales [3]. Various 3D printing techniques such as material extrusion, powder bed fusion [4,5], binder jetting [6] and vat photopolymerization [7] have been used to fabricate biologically inert tissue constructs by replacing non-medical grade materials with biocompatible and bioresorbable materials such as synthetic and natural polymers [8], natural and inorganic ceramic materials [9,10], or recently developed biodegradable metals [11]. Adaptation of 3D printing into tissue engineering brings unique capabilities in rapid fabrication of tissue scaffolds with controlled porosity and internal architecture, tunable mechanical and structural properties, and the ability to load drug or protein molecules for enhanced cellular response and customized/multifunctional characteristics, which can guide the cellular environment for enhanced tissue regeneration.…”

Layer Manufacturing for in Vivo Devices

“…been several developments regarding the inteWilliams et al [91] experimented with the SLS of gration of such capabilities in the production propolycaprolactone (PCL), which is bioresorbable, with cess, but there have been relatively few related potential applications for bone and cartilage repair. developments in the design capabilities for this.…”