Bone Regeneration of Osteoporotic Vertebral Body Defects Using Platelet-Rich Plasma and Gelatin β-Tricalcium Phosphate Sponges

Abstract

The objective of the present study was to investigate the effect of platelet-rich plasma (PRP) combined with gelatin β-tricalcium phosphate (β-TCP) sponge on bone generation in a lumbar vertebral body defect of ovariectomized rat. After creating critical-size defects in the center of the anterior vertebral body, the defects were filled with the following materials: (1) no material (control group), (2) gelatin β-TCP sponge with PRP (PRP sponge group), and (3) gelatin β-TCP sponge with phosphate-buffered saline (PBS sponge group). Microcomputed tomography and histological evaluation were performed immediately after surgery and at 4, 8, and 12 weeks to assess bone regeneration. Biomechanical test was also performed at postoperative week 12. In the PRP sponge group, both imaging and histological examination showed that visible osteogenesis was first induced and additional growth of bone tissue was observed in the transplanted sponge, compared with the PBS sponge group. There was no negative effect of either PRP sponge or PBS sponge transplantation on bone tissue generation around the periphery of the defect. Biomechanical test showed increased stiffness of the affected vertebral bodies in the PRP sponge group. These results indicate that PRP-impregnated gelatin β-TCP sponge is effective for facilitating bone regeneration in lumbar vertebral bone defect under osteoporotic condition. PRP combined with gelatin β-TCP sponges could be potentially useful for developing a new approach to vertebroplasty for osteoporotic vertebral fracture.

Platelet Features and Derivatives in Osteoporosis: A Rational and Systematic Review on the Best Evidence

“…Risk of bias of animal studies was high for almost all the examined studies. Among the 13 included in vivo studies, three for PLT functions during OP and 10 for PLT derivatives in OP, 10 of them have not declared the method of sequence generation [41,42,[49][50][51][52][53]56,57], in one study the method was unclear [55] and in the remaining two studies the method of sequence generation was clearly declared [40,58]. The majority (n = 7) of the studies showed that groups were similar concerning baseline characteristics (i.e., age, weight, sex) and two studies showed that allocation was adequately concealed [40,58].…”

“…All studies used PRP as PLT products with the exception of a study which used L-PRF [58]. Six of these studies (60%) also employed a scaffold/biomaterial (calcium phosphate, calcium aluminate/calcium aluminate-melatonin, β-tricalcium phosphate, bovine bone graft, nanoporous TiO 2 , hemostatic sponge) to incorporate the PLTs derivatives and subsequently evaluated bone regeneration in calvaria [51,58], tibia [54,56] and in caudal and lumbar vertebrae [53,57]. Clafshenkel et al [51] evaluating a calcium aluminate and calcium aluminate-melatonin scaffolds implanted in a critical size calvaria defect of OVX rats, showed that the addition of PRP did not significantly improve degree, intensity and abundance of osteoid tissue mineralization and bone formation in either of the two scaffolds [51].…”

“…Additionally, it was seen that PRP in association with TiO 2 not only promoted the osteogenesis but also increased the expression of RUNX2 and COL1 genes and suppressed osteoclastogenesis with increased expression of OPG and decreased levels of RANKL [54]. Despite calvaria defects and long bones defects are the most frequently models used to evaluate bone regeneration and healing during OP, also vertebrae, despite the higher cancellous bone content and the different anatomical and biomechanical properties, were used to evaluate the role of scaffold/biomaterial in association to PRP [53,57]. Two in vivo studies in OVX animals showed that incorporating PRP into calcium phosphate cement [53] and β-TCP sponge [57] accelerated osteoconduction in the caudal [53] and lumbar [57] site, also demonstrating an improvement of the trabecular bone microarchitecture.…”

“…Despite calvaria defects and long bones defects are the most frequently models used to evaluate bone regeneration and healing during OP, also vertebrae, despite the higher cancellous bone content and the different anatomical and biomechanical properties, were used to evaluate the role of scaffold/biomaterial in association to PRP [53,57]. Two in vivo studies in OVX animals showed that incorporating PRP into calcium phosphate cement [53] and β-TCP sponge [57] accelerated osteoconduction in the caudal [53] and lumbar [57] site, also demonstrating an improvement of the trabecular bone microarchitecture. Additionally, calcium phosphate cements associated to PRP improve the bone mineral density [53] and increase the stiffness of the affected vertebral bodies [57].…”

“…Two in vivo studies in OVX animals showed that incorporating PRP into calcium phosphate cement [53] and β-TCP sponge [57] accelerated osteoconduction in the caudal [53] and lumbar [57] site, also demonstrating an improvement of the trabecular bone microarchitecture. Additionally, calcium phosphate cements associated to PRP improve the bone mineral density [53] and increase the stiffness of the affected vertebral bodies [57]. Finally, Rocha et al [56] used a hydrolyzed collagen sponge made from freeze-dried sterile porcine gelatine as carrier for allogenic BMSCs and PRP, alone or in combination, to evaluate the repair of bone failure in tibiae of osteoporotic rabbits secondary to estrogenic deprivation and iatrogenic hypercortisolism [56].…”