Biomechanical properties of 3D-printed bone scaffolds are improved by treatment with CRFP

Carlos G Helguero,David E Komatsu,Vamiq M Mustahsan,Sunjit Parmar,Imin Kao,Srinivas Pentyala,John L Pfail,Sahana Pentyala

doi:10.1186/s13018-017-0700-2

Abstract

BackgroundOne of the major challenges in orthopedics is to develop implants that overcome current postoperative problems such as osteointegration, proper load bearing, and stress shielding. Current implant techniques such as allografts or endoprostheses never reach full bone integration, and the risk of fracture due to stress shielding is a major concern. To overcome this, a novel technique of reverse engineering to create artificial scaffolds was designed and tested. The purpose of the study is to create a new generation of implants that are both biocompatible and biomimetic.Methods3D-printed scaffolds based on physiological trabecular bone patterning were printed. MC3T3 cells were cultured on these scaffolds in osteogenic media, with and without the addition of Calcitonin Receptor Fragment Peptide (CRFP) in order to assess bone formation on the surfaces of the scaffolds. Integrity of these cell-seeded bone-coated scaffolds was tested for their mechanical strength.ResultsThe results show that cellular proliferation and bone matrix formation are both supported by our 3D-printed scaffolds. The mechanical strength of the scaffolds was enhanced by trabecular patterning in the order of 20% for compression strength and 60% for compressive modulus. Furthermore, cell-seeded trabecular scaffolds modulus increased fourfold when treated with CRFP.ConclusionUpon mineralization, the cell-seeded trabecular implants treated with osteo-inductive agents and pretreated with CRFP showed a significant increase in the compressive modulus. This work will lead to creating 3D structures that can be used in the replacement of not only bone segments, but entire bones.

Highlights

One of the major challenges in orthopedics is to develop implants that overcome current postoperative problems such as osteointegration, proper load bearing, and stress shielding
Cellular growth on acrylonitrile butadiene styrene (ABS) scaffolds Incubating the seeded scaffolds under osteogenic conditions showed osteoblasts promoting matrix formation and mineralization, as evidenced by Alizarin red staining in 3D reconstructed confocal z-sections images of cells grown on scaffolds (Fig. 4a)
The trabecular patterning of the normal bone to create biomimetic structures, a unique feature compared to other approaches [13] was used in this study for two main reasons: to create a more conductive environment for bone matrix formation and, to mimic the structural support that trabeculae pattern gives to the bone

Summary

Introduction

One of the major challenges in orthopedics is to develop implants that overcome current postoperative problems such as osteointegration, proper load bearing, and stress shielding. Current implant techniques such as allografts or endoprostheses never reach full bone integration, and the risk of fracture due to stress shielding is a major concern. Low mechanical strength is a major challenge in porous scaffolds and is primarily controlled by pore volume. This is true for onedimensional (1D) and 3D-printed scaffolds and limits

Objectives

Methods

Results

Discussion

Conclusion