Elastic and surgeon friendly electrospun tubes delivering PDGF-BB positively impact tendon rupture healing in a rabbit Achilles tendon model. (February 2020)

• Record Type: Journal Article
• Authors: Evrova, Olivera; Bürgisser, Gabriella Meier; Ebnöther, Christian; Adathala, Ashal; Calcagni, Maurizio; Bachmann, Elias; Snedeker, Jess G.; Scalera, Chiara; Giovanoli, Pietro; Vogel, Viola; Buschmann, Johanna
• Is Part Of: Biomaterials. Volume 232(2020)
• Publication Date: 2020-02
• Subjects: Electrospinning -- PDGF-BB release -- Tendon repair -- Tendon biomechanics -- Tissue engineering; Biomedical materials -- Periodicals; Biocompatible Materials -- Periodicals; Biomatériaux -- Périodiques; 610.28
• DOI: 10.1016/j.biomaterials.2019.119722
• Languages: English
• ISSNs: 0142-9612

Abstract

Abstract: A major problem after tendon laceration is the low mechanical strength of the repaired tissue. One viable strategy for improving the functional and biomechanical properties of ruptured and repaired tendons is the delivery of growth factors at the injury site. Here, bioactive and reversibly expandable double-layered emulsion and coaxially electrospun tubes made from biodegradable DegraPol® (DP) (polyester urethane), delivering platelet-derived growth factor BB (PDGF-BB), are explored as implants to improve tendon healing in a rabbit Achilles tendon full laceration model. In vitro studies showed that both emulsion and coaxially electrospun scaffolds allow sustained delivery of bioactive PDGF-BB with similar release kinetics (150–190 pg PDGF-BB/mg of DP scaffold) over a period of 30 days. In vivo assessment after three weeks showed that PDGF-BB delivery through the bioactive DP tubes increased the tensile strength of the treated tendons 2-fold without additional pro-fibrotic effects, i.e., cell hyperproliferation or increase in α-smooth muscle actin expression at the wound site. While no major differences in ECM composition at the wound site were observed for ± PDGF-BB treated samples, collagen I and III were upregulated and fibronectin was downregulated compared to native tendons. In areas away from the wound, increased fibronectin expression was observed qualitatively in regions with lower collagen I and III expression. Both types of bioactive DP tubes provided surgeon-friendly and stable implants to deliver bioactive molecules and positively affected the strength of the repaired tendons after 3 weeks, thus presenting promising bioactive implants for clinical applications in the tendon repair field. Graphical abstract: ToC Keywords: biomedical applications, block copolymers, drug delivery, fibers, tissue engineering. Elastic and bioactive DegraPol® tubes, produced by two electrospinning techniques that can deliver bioactive PDGF-BB in a sustained manner at the site of tendon rupture, have been developed and assessed in a rabbit in vivo model. Three weeks post-implantation, treatment with the bioactive tubes leads to improvement of the tensile strength of the ruptured and healing tendons. Image 1