In vivo efficacy of bone‐marrow‐coated polycaprolactone scaffolds for the reconstruction of orbital defects in the pig

Abstract

Alloplastic materials offer a number of advantages over bone autografts in the reconstruction of craniofacial defects. These include: lack of donor site morbidity, unlimited quantities of available material, and the possibility to conform exactly to the defect. An ideal bioresorbable material would degrade slowly, and have osteoconductive properties to allow replacement and remodeling by osseous tissue. This is seldom observed, the materials instead being replaced by fibrous tissue. Polycaprolactone (PCL), an FDA-approved bioresorbable polymer, has several properties that might make it suitable for reconstruction of craniofacial defects. The technique of fused deposition modeling (FDM) allows for the fabrication of highly reproducible bioresorbable 3D scaffolds. The nature of the fully interconnected pore network might enhance vascular ingrowth and osteoconductive properties. It was hypothesized that coating the scaffolds in bone marrow might enhance bone formation due to the osteoinductive nature of the bone-marrow mesenchymal cells. This study aimed to test these hypotheses in the pig model. Defects measuring 2 x 2 cm were surgically created in each orbit of eight Yorkshire pigs. The orbits were divided into three groups: Group 1 (n=4), no reconstruction (control); Group 2 (n=6), reconstruction with no coated PCL scaffolds; and Group 3 (n=6) reconstruction with bone-marrow-coated PCL scaffolds. The results were evaluated at 3 months by histological and histomorphometric analyses. The defects in Group 1 were covered with fibrous scar tissue. The shape of the reconstructed area was insufficient. The defects in Groups 2 and 3 were reconstructed correctly. In Group 2 the noncoated scaffolds showed 4.5% of new bone formation compared with 14.1% in Group 3, which is statistically significant (p<0.05). The entirely interconnected 3D polycaprolactone scaffold seems to be a promising material. It induces the bone ingrowth required for reconstructing craniofacial and orbital defects. Further long-term evaluations of these PCL scaffolds must be made in order to confirm these conclusions.

Mechanical response of 3D Insert® PCL to compression

“…This approach led to the fabrication of scaffolds able to bear mechanical forces, providing at the same time an architecture and a matrix similar to the bone tissue niche [2]. Among those, polycaprolactone (PCL), a thermoplastic polymer with low glass transition and low melting temperature [3], is gaining interest as temperature dependent processes can be employed to shape it, enabling control over features at micro scale [4]- [6]. PCL was also shown to be biocompatible [7] and have slow degradation rates due to its high degree of crystallinity and hydrophobicity [8], [9].…”

Porous alginate/poly(ε-caprolactone) scaffolds: preparation, characterization and in vitro biological activity

“…PLC has been approved by the FDA for preparing biomedical devices as urethral catheters, drug delivery systems and resorbable sutures (71), and it has been proposed as a material for tissue engineering of bone and cartilage (11,(20)(21)(22)(23)(24)(25). Due to its hydrophobic characteristics and semi-crystalline solid phase structure, the entry of biological fluids within PCL scaffolds is hindered and therefore, subsequent chemical degradation is delayed thus, avoiding the local accumulation of toxic substances and the onset of inflammatory processes (20).…”

“…It degrades through hydrolytic scission and has resistance to rapid hydrolysis. Because of its biocompatibility properties, degradation rate and mechanical strength, it has been investigated as a biomaterial for medical drug delivery devices (20)(21)(22)(23)(24)(25), and load-bearing bone tissue engineering applications (26,27). PCL is characterized by a resorption time slower than other polyesters (28,29), and a negligible weight loss (below 2% in 30 days) (30,31).…”

Biomimetic Structured Porogen Freeform Fabrication System for Tissue Engineering

“…In this study, PCL and Calcium Phosphate (CaP) were chosen as the injective biomaterials. The innate rigidity of PCL makes this material well suited for the fabrication of tissue engineering scaffolds, mainly for orthopedic applications [Shin, Yoshimoto and Vacanti, 2004;Chen, Bei andRohner, Hutmacher, Cheng, Oberholzer andHammer, 2003]. PCL was attractive also due to its low cost and sustained biodegradability although it is not bioactive [Kim, Knowles and Kim, 2003].…”