Development of biodegradable polycaprolactone film as an internal fixation material to enhance tendon repair: an in vitro study

Abstract

BackgroundCurrent tendon repair techniques do not provide sufficient tensile strength at the repair site, and thus early active motion rehabilitation after tendon repair is discouraged. To enhance the post-operative tensile strength, we proposed and tested an internal fixation technique using a polycaprolactone (PCL) biofilm. PCL was chosen for its good biocompatibility, excellent mechanical strength, and an appropriate degradation time scale.MethodsPCL biofilms were prepared by a modified melt-molding/leaching technique, and the physical and mechanical properties and in vitro degradation rate were assessed. The pore size distribution of the biofilm and the paratenon of native tendons were observed using scanning electron microscopy. Next, we determined whether this biofilm could enhance the tensile strength of repaired tendons. We performed tensile tests on rabbit Achilles tendons that were first lacerated and then repaired: 1) using modified Kessler suture combined with running peripheral suture (‘control’ group), or 2) using biofilm to wrap the tendon and then fixation with sutures (‘biofilm’ group). The influence of different repair techniques on tendon tensile strength was evaluated by mechanical testing.ResultsThe novel biofilm had supple texture and a smooth surface. The mean thickness of the biofilm was 0.25 mm. The mean porosity of the biofilm was 45.3%. The paratenon of the rabbit Achilles tendon had pores with diameters ranging from 1 to 9 μm, which were similar to the 4–12 μm diameter pores in the biofilm cross-section. The weight loss of the biofilms at 4 weeks was only 0.07%. The molecular weight of PCL biofilms did not change after immersion in phosphate buffered saline for 4 weeks. The failure loads of the biofilm were similar before (48 ± 9 N) and after immersion (47 ± 7 N, P > 0.1). The biofilm group had ~70% higher mean failure loads and 93% higher stiffness compared with the control group.ConclusionsWe proposed and tested an internal fixation technique using a PCL biofilm to enhance tendon repair. Internal fixation with the biofilm followed by standard suturing can significantly increase the tensile strength of tendon repair sites. This technique has the potential to allow active motion rehabilitation during the early post-operative period.

In VitroBehavior of Human Adipose Tissue-Derived Stem Cells on Poly(ε-caprolactone) Film for Bone Tissue Engineering Applications

“…Moreover, over the last decade, since polymers lack osteoconductivity, considerable attention has been directed toward their combination with natural or synthetic bioceramics, such as hydroxyapatite or calcium phosphate. This strategy has permitted the creation of many composite scaffolds that imitate the natural structure of bone with superior osteoconductive property, stimulating MSCs to foster a favorable osteogenic microenvironment [ 31 , 40 , 48 , 49 ].…”

In VivoEvaluation of Electrospun Polycaprolactone Graft for Anterior Cruciate Ligament Engineering

“…39 Furthermore, its standalone use has more recently been proposed for extra-articular tendon repair and replacement. 9 In the current study, we hypothesize that an electrospun PCL graft would promote collagen deposition and elicit minimal immunogenic response in an IA rodent model of ACL reconstruction and that maturation of the graft would result in improved biomechanical properties over time.…”

“…20 However, recent work by Hu et al has demonstrated the potential feasibility of unblended PCL as a polymer for reinforcing tendon repair. 9 Electrospinning is a relatively inexpensive technique for submicron and micron diameter fibers from polymer solutions. Electrospinning is of great interest as the resulting fiber diameters are in the size range (submicron to nanometer) of the extracellular matrix microstructures, particularly the higher ordered collagen microfibrils.…”

Multifaceted Design and Emerging Applications of Tissue Adhesives

“…Adhesive materials could provide instructive cues to promote tissue repair and regeneration. [ 100–157 ] These cues can be biochemical, cellular, or mechanical. The strategies to design adhesives to match tissue mechanics have been thoroughly reviewed elsewhere.…”