Preclinical comparison of novel rotator cuff repair scaffolds

Thesis

Background: Rotator cuff tears affect up to 16% of the adult population, but inadequate treatment options are currently available. Our research group has developed a range of degradable scaffolds, manufactured from electrospinning and weaving, designed to assist the tendon repair both biologically and mechanically. The scaffolds have been successfully tested in vitro, however, to further assess the potential of these materials for clinical applications, an in vivo study is necessary.

Aim: The overall aim of this study was to assess the safety and biocompatibility of the scaffolds in vivo. The objectives included optimisation of the weaving process and assessment of the systemic and local host reaction to scaffolds upon implantation.

Methodology: The weaving process was first optimised to achieve satisfactory mechanical properties for the woven components. For the in vivo study, four different scaffolds were implanted into the shoulder of Lewis rats. The infraspinatus was transected and repaired using the scaffolds and at six timepoints up to 5 months, the shoulder joint was dissected for histological assessment. The foreign body response was assessed by hematoxylin and eosin (H&E) staining and by evaluating the presence of foreign body giant cells (FBGCs).

Results and Discussion: The optimisation of the weaving process resulted in the development of scaffolds with improved tensile strength. Upon implantation, most scaffolds did not indicate any severe adverse reaction. However histology revealed that the presence of large quantities of electrospun material elicits a strong foreign body reaction, with significantly more FBGCs in the group which had an electrospun scaffold compared to the positive control.

Conclusion: Scaffolds containing no or moderate electrospun materials seemed to be well tolerated by the rats and appear safe for human use. However, implanting large volumes of electrospun material may elicit an unwanted foreign body reaction and more in vivo work is needed to understand its tissue integration.

Authors: Lostis, E

• Publication date: 2014
• Type of award: MSc by Research
• Level of award: Masters
• Awarding institution: Oxford University, UK
• Language: English
• Keywords: Tendinopathy; Implant; Tendon; Rotator cuff; Electrospinning; Polydioxanone
• Subjects: Medical Sciences; Orthopaedics