A Novel Porcine Graft for Regeneration of Bone Defects

Eisner Salamanca,Wei-Fang Lee,Wei-Jen Chang,Sheng-Wei Feng,Chin-Yi Lin,Haw-Ming Huang,Che-Tong Lin

doi:10.3390/ma8052523

Eisner Salamanca, Wei-Fang Lee + Show 5 more

Open Access

https://doi.org/10.3390/ma8052523

Copy DOI

Abstract

Bone regeneration procedures require alternative graft biomaterials to those for autogenous bone. Therefore, we developed a novel porcine graft using particle sizes of 250–500 μm and 500–1000 μm in rabbit calvarial bone defects and compared the graft properties with those of commercial hydroxyapatite (HA)/beta-tricalcium phosphate (β-TCP) over eight weeks. Surgery was performed in 20 adult male New Zealand white rabbits. During a standardized surgical procedure, four calvarial critical-size defects of 5 mm diameter and 3 mm depth were prepared. The defects were filled with HA/β-TCP, 250–500 μm or 500–1000 μm porcine graft, and control defects were not filled. The animals were grouped for sacrifice at 1, 2, 4, and 8 weeks post-surgery. Subsequently, sample blocks were prepared for micro-computed tomography (micro-CT) scanning and histological sectioning. Similar bone formations were observed in all three treatment groups, although the 250–500 μm porcine graft performed slightly better. Rabbit calvarial bone tissue positively responded to porcine grafts and commercial HA/β-TCP, structural analyses showed similar crystallinity and porosity of the porcine and HA/β-TCP grafts, which facilitated bone formation through osteoconduction. These porcine grafts can be considered as graft substitutes, although further development is required for clinical applications.

Highlights

In past decades, multiple reconstructive procedures have been assessed as periodontal regenerative treatments for deep infrabony defects that are associated with periodontal pockets [1,2] and furcation defects [3] and to prevent bone crest resorption after tooth extraction [4]
The surfaces had a spherical morphology comprising a mixture of 250–500 μm and 500–1000 μm particles, which provided a favorable matrix for attachment and proliferation of osteoblasts cells (Figure 1)
The energy dispersive spectrometry (EDS) analyses showed very high accuracy between calcium (Ca) and phosphorus (P), which were present at a Ca/P ratio of 1.668 (28.16% and 16.88%, respectively), and the porcine graft profile resembled that of the HA/β-TCP structure (Table 1)

Summary

Introduction

Multiple reconstructive procedures have been assessed as periodontal regenerative treatments for deep infrabony defects that are associated with periodontal pockets [1,2] and furcation defects [3] and to prevent bone crest resorption after tooth extraction [4]. Disadvantages of autogenous bone grafts include limited availability, tendency toward partial resorption, requirement of additional surgery, and increased morbidity [5]. Further studies of alternative biomaterials, such as allogenic and xenogenic grafts, and alloplastic materials, are required to determine their efficacy in osteoconduction, osteoinduction, and osteogenesis [3] and to assess their clinical suitability for bone regeneration [6,7,8]. Biphasic calcium phosphate (BCP) is a bioinert and bioactive alloplastic material that comprises mixtures of hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) at varying HA/β-TCP ratios [9,10]. Previous studies showed that BCP comprising approximately 60% HA and 40% β-TCP allows control of resorption and maintenance of osteoconductive properties [11,12,13,14,15,16]. Several investigators found that the optimal macroporosity of this material for the ingrowth of bone tissue is between 150 and 500 μm [12]

Methods

Results

Discussion

Conclusion