Comparison of TCP and TCP/HA Hybrid Scaffolds for Osteoconductive Activity

Abstract

Two types of porous ceramic scaffolds were prepared, consisting of β-tricalcium phosphate (TCP) or the mixed powder of TCP and hydroxyapatite (HA) at a 2:1 mass ratio. A variety of methods have been used to fabricate bone scaffolds, while the sintering approach was adopted in this work. An extremely high temperature was used on sintering that proposed to consolidate the ceramic particles. As revealed by SEM, a well opened pore structure was developed within the scaffolds. The θ-values were measured to be of 73.3° and 6.5° for the composite scaffold and TCP sample, respectively. According to XRD patterns, the existence of grains coalescence and partial bonding between HA and TCP powders was demonstrated. Scaffold mechanical property in the term of flexural strength was also determined. The result showed decreasing of the strength by HA supplement, suggesting the more brittle characteristic of HA in comparison with TCP. By soaking the composite scaffold in PBS for a period of 2 weeks, transformation from particles to flank-like crystalline was clearly observed. Such change was found to be favorable for cell attachment, migration, and growth. By implanting cell-seeded scaffolds into nude mice, an abundant osseous extracellular matrix was identified for the composite implants. In contrast, the matrix was minimally detected in TCP implanted samples. Thus, the composite scaffold was found superior for hard tissue regeneration.

ALP gene expression in cDNA samples from bone tissue engineering using a HA/TCP/Chitosan scaffold

“…This suggests that there was increased osteoblast activity after two weeks of treatment, although it was not statistically significant. This is consistent with research conducted by Solomon and Wongwitwichot, showing the scaffold combination of HA/TCP can support bone formation better than HA or TCP alone [9,11]. In contrast, the subject treated with HA/TCP 70:30 had a trend of decreasing ALP expression.…”

“…HA and TCP are major components of the natural bone matrix, and thus are highly biocompatible [1,10]. HA and TCP have osteoconductive properties, with the ability to bind to bone and soft tissue, and to stimulate bone growth [11]. Although HA and TCP have suitable properties for bone tissue engineering, they are fragile, rigid (hard to adjust to a specific form required as a bone substitute, and have a low mechanical stability [1,12].…”

“…In a study comparing the use of HA/TCP to pure HA transplanted to the dorsum of a rat, minimal bone formation was seen on the HA transplantation relative to HA/TCP [9]. Another study, comparing HA/TCP to TCP in osteogenic activity, showed substantial layers of bone tissue with abundant extracellular matrix on the scaffold implantation of HA/TCP, but the TCP scaffold had little new bone tissue [11]. These studies demonstrated that HA/TCP has better osteogenic potential than pure HA scaffold or pure TCP scaffold.…”

Predicting the Elastic Properties of Selective Laser Sintered PCL/β-TCP Bone Scaffold Materials Using Computational Modelling

“…A summary of the elastic moduli of PCL for different processing methods is 4 given in Table 1. β-TCP has good biocompatibility and osteoconductivity and has been used both on its own and in combination with polymers in scaffold applications 11,21,32,35,45,59 .…”

“…A summary of the elastic moduli of PCL for different processing methods is 4 given in Table 1. β-TCP has good biocompatibility and osteoconductivity and has been used both on its own and in combination with polymers in scaffold applications 11,21,32,35,45,59 .PCL/ β-TCP scaffolds for bone tissue engineering applications similar to those used in this study have been fabricated with varying volume fractions 25,26,28,33,54 . An advantage of SLS is the high degree of repeatability and conformity of the scaffold to the original 3D CAD design on the macro-scale compared to the relatively random distribution of pores in scaffolds fabricated using, for example, salt leaching 8,27,48,61 .…”