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Lainate, Italy

Buschmann J.,University of Zurich | Meier-Burgisser G.,University of Zurich | Bonavoglia E.,Ab Medica | Neuenschwander P.,Ab Medica | And 3 more authors.
Journal of Tissue Engineering and Regenerative Medicine | Year: 2013

In tendon rupture repair, improvements such as higher primary repair strength, anti-adhesion and accelerated healing are needed. We developed a potential carrier system of an electrospun DegraPol® tube, which was tightly implanted around a transected and conventionally sutured rabbit Achilles tendon. Histomorphometric analysis of the tendon tissue 12weeks postoperation showed that the tenocyte density, tenocyte morphology and number of inflammation zones were statistically equivalent, whether or not DegraPol tube was implanted; only the collagen fibres were slightly less parallelly orientated in the tube-treated case. Comparison of rabbits that were operated on both hind legs with ones that were operated on only one hind leg showed that there were significantly more inflammation zones in the two-leg cases compared to the one-leg cases, while the implantation of a DegraPol tube had no such adverse effects. These findings are a prerequisite for using DegraPol tube as a carrier system for growth factors, cytokines or stem cells in order to accelerate the healing process of tendon tissue. © 2012 John Wiley & Sons, Ltd.

Meier Burgisser G.,University of Zurich | Calcagni M.,University of Zurich | Muller A.,University of Zurich | Bonavoglia E.,Ab Medica | And 4 more authors.
BioMed Research International | Year: 2014

Purpose. One of the great challenges in surgical tendon rupture repair is to minimize peritendinous adhesions. In order to reduce adhesion formation, a physical barrier was applied to a sutured rabbit Achilles tendon, with two different immobilization protocols used postoperatively. Methods. Thirty New Zealand white rabbits received a laceration on the Achilles tendon, sutured with a 4-strand Becker suture, and half of the rabbits got a DegraPol tube at the repair site. While fifteen rabbits had their treated hind leg in a 180° stretched position during 6 weeks (adhesion provoking immobilization), the other fifteen rabbits were recasted with a 150° position after 3 weeks (adhesion inhibiting immobilization). Adhesion extent was analysed macroscopically, via ultrasound and histology. Inflammation was determined histologically. Biomechanical properties were analysed. Results. Application of a DegraPol tube reduced adhesion formation by approximately 20% - independently of the immobilization protocol. Biomechanical properties of extracted specimen were not affected by the tube application. There was no serious inflammatory reaction towards the implant material. Conclusions. Implantation of a DegraPol tube tightly set around a sutured tendon acts as a beneficial physical barrier and prevents adhesion formation significantly - without affecting the tendon healing process. © 2014 Gabriella Meier Bürgisser et al.

Buschmann J.,University of Zurich | Welti M.,University of Zurich | Hemmi S.,University of Zurich | Neuenschwander P.,Ab Medica | And 5 more authors.
Tissue Engineering - Part A | Year: 2011

Tissue engineering of bone grafts was addressed in a critical-sized model on the chick chorioallantoic membrane model, using DegraPol® foam as scaffold material. The scaffolds were seeded with cultures of human osteoblasts and human endothelial cells, respectively, or with a co-culture of the two cell types (control: no cells). In vitro samples (7 days cultivation) and ex vivo chorioallantoic membrane model samples at incubation day 15 were analyzed by high-field magnetic resonance imaging (MRI) and histology. The co-culture system performed best with respect to perfusion, as assessed by contrast-enhanced MRI using gadolinium-diethylene-triamine-pentaacetic acid (DTPA). The scaffold seeded by the co-culture supported an increased vascular ingrowth, which was confirmed by histological analysis. DegraPol foam is a suitable scaffold for bone tissue engineering and the MRI technique allows for nondestructive and quantitative assessment of perfusion capability during early stages of bone forming constructs. © 2011 Mary Ann Liebert, Inc.

Evrova O.,University of Zurich | Evrova O.,ETH Zurich | Houska J.,University of Zurich | Welti M.,University of Zurich | And 5 more authors.
Macromolecular Bioscience | Year: 2016

Healing of tendon ruptures represents a major challenge in musculoskeletal injuries and combinations of biomaterials with biological factors are suggested as viable option for improved healing. The standard approach of repair by conventional suture leads to incomplete healing or rerupture. Here, a new elastic type of DegraPol® (DP), a polyester urethane, is explored as a delivery device for platelet-derived growth factor—BB (PDGF-BB) to promote tendon healing. Using emulsion electrospinning as an easy method for incorporation of biomolecules within polymers, DegraPol® supports loading and release of PDGF-BB. Morphological, mechanical and delivery device properties of the bioactive DP scaffolds, as well as differences arising due to different electrospinning parameters are studied. Emulsion electrospun DP scaffolds result in thinner fibers than pure DP scaffolds and experience decreased strain at break [%], but high enough for successful surgeon handling. PDGF-BB is released in a sustained manner from emulsion electrospun DP, but not completely, with still large amount of it being inside the polymeric fibers after 30 d. In vitro studies show that the bioactive scaffolds promote tenocyte proliferation in serum free and serum+ conditions, demonstrating the potential of this surgeon-friendly bioactive delivery device to be used for tendon repair. (Figure presented.) . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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