Project

Discipline

biomechanics; surgery; mesenchymal; stem cells; microcarriers; intervertebral; regeneration

Lead
Zelltherapie bei degenerativen Bandscheibenerkrankungen unter der Anwendung von Microcarriern mit kovalent gebundenen WachstumsfaktorenRückenschmerzen sind eine wichtige - und teure - Morbiditätsursache in der heutigen Gesellschaft. Die Behandlungsmodalitäten zur Schmerzlinderung und Abmilderung von Funktionsverlusten zielen häufig auf die Bandscheibe ab. Seit kurzem ist ein explosionsartig gesteigertes Forschungsinteresse an degenerativen Bandscheibenerkrankungen sowie der Verwendung von biologischen Methoden zur Bandscheibenregeneration zu beobachten. Eine der größten Herausforderungen für die Regenerationstherapie ist die Übertragung der Therapieansätze auf die in vivo Situation, insbesondere in eine reale Therapie im Gegensatz zu vereinfachten Tiermodellen. Wir wollen einen solchen in-vivo-Ansatz auf der Grundlage unserer bisherigen wissenschaftlichen und klinischen Erfahrungen weiterentwickeln und verbessern.
Lay summary
Dieses Projekt stellt eine Fortsetzung unseres vorangegangenen Projekts dar, in welchem es um eine Therapie mit injizierbaren Stammzellen zur Bandscheibenregeneration großer Hunde ging. Hunde mit natürlich vorkommenden degenerativen Bandscheibenerkrankungen stellen eine wertvolle Ressource für die Forschung dar. Der Vorteil dieser Ressource liegt in einer Verringerung der Anzahl an durchgeführten Tierversuchen und bietet durch die richtige Kombination von Risikofaktoren auch ein realistisches Modell. An dieser Stelle werden wir die injizierbare Therapie weiterentwickeln, die aus mesenchymalen Stammzellen und speziellen Kollagenmicrocarriern besteht. Diese Microcarrier wurden durch aktive, an ihre Oberfläche vernetzte Proteine weiter verstärkt. Wir werden zwei Verfahren zur Vernetzung anwenden und die Ergebnisse auf drei Ebenen unter Anwendung von Methoden aus der Molekularbiologie, der Biomechanik und Wirbelsäulenchirurgie validieren. Die postoperative Nachsorge der Tiere ist vergleichbar mit der eines menschlichen Patienten – sie wird durchgeführt mit MRI, funktionalen Tests und den Berichten über mögliche Schmerzen durch die Besitzer der Tiere. Die Ergebnisse werden mit einer Kontrollgruppe verglichen, bei denen die Standard-Wirbelsäulenchirurgie (ohne Stammzellen) zur Anwendung kam. Gegenwärtige Behandlungsansätze Bandscheibenerkrankungen - konservativ wie operativ – zielen nur auf die Symptome und nicht auf die zugrundeliegende Erkrankung ab, wenn gleich sie wirksam sind was die Verringerung der Schmerzen angeht. Eine vielversprechende Therapie wäre eine, die eine Bandscheibe von innen heraus zu reparieren oder komplett wieder herzustellen vermag.  Obwohl es Forschung über die Biologie der Bandscheibendegeneration und –regeneration gab, wurde wenig davon in die medizinische Praxis übertragen. Wir arbeiten daran, dass die Forschungsergebnisse in der Tiermedizin Anwendung finden und hoffen, dass dieser Ansatz den Weg für eine zukünftige Humantherapie bereiten wird.

Direct link to Lay Summary

Last update: 19.08.2015

Lead
Back pain is a major - and expensive - source of morbidity in today’s society and the treatment modalities towards pain relief and relief of loss of function frequently target the intervertebral disc. Recently there is an explosion of research interest in degenerative disc disease and the use of biological methods for disc regeneration. A major challenge for regenerative therapy is the delivery of the therapy in vivo, especially in a real therapy in contrast with simplified animal models. Here we develop and improve such in an-vivo approach based on our recent scientific and clinical experience
Lay summary
This project is founded  as  a continuation of our project to use injectable stem cells therapy for intervertebral disc regeneration in large dogs. Dogs with naturally occurring degenerative disc disease are valuable resource which offers the advantage of not only reduced animal experimentation but is a realistic model because of the right combination of age, genetics, biochemistry and biomechanical risk factors. Here we will further develop  injectable therapy which consist of autologous mesenchymal stem cells, and recently developed collagen microcarriers further enhanced with active proteins bound (crosslinked) to the surface of these microcarriers. We will use two methods for crosslinking and validate the results on three levels using methods of molecular and cell biology, biomechanics and stem cell enhanced spine surgery. The animals will be followed up postoperatively with similar methods as human patients are – functional tests, MRI and  reporting of pain by the owners. The results will be compared to a control group treated with standard spine surgery (without stem cells).     Scientific and Social Context of the Research Project Current treatments of degenerative disc disease -  conservative and surgical - although can be very effective in reducing pain are targeting the symptoms and not the underlying disease. Sometimes surgery can even lead to further degenerative changes. A promising therapy would be one, which repairs or even restores the disc from inside, such as stem cell therapy.  Although  research has been done on the biology of intervertebral disc degeneration and regeneration, very little of this research has been translated in the medical practice. Here we try to make this translation first in the veterinary practice and hope that this will open the avenue for a future human therapy.

Direct link to Lay Summary

Last update: 19.08.2015

Active participation

Communication	Title	Media	Place	Year

Number	Title	Start	Funding scheme

This grant application is a continuation of our project to establish injectable stem cell therapy for intervertebral disc (IVD) repair. Our approach allows feedbacks between basic research in IVD biology, tissue engineering, biomechanics of the IVD and existing clinical practices with the ultimate aim to repair degenerated discs.So far, the close interaction of biological, engineering and surgical competences allowed us to deal with problems which are in the way of clinical implementation of basic IVD research. We studied patient variability (quality of the patient’s cells), in vitro senescence of the expanded cultures, cell speed as quality control, microcarrier development and injectability, patient recruitment, microcarrier extrusion and MRI imaging. By creating easily injectable microcarriers, we developed a new, simplified and robust but safe workflow, which can be handled with medical instead of research hardware, however our wish to develop a single step expansion-differentiation procedure was not feasible because of formation of spheroids with too large size. The microcarriers were initially produced from different medically approved for human use collagen and gelatine sponges. We selected one of the best materials for growth and handling of cells with superior performance compared to many research systems. In basic research, the biomechanical and clinical properties of the proposed biological solutions are rarely optimized and finalized. Simultaneously with the biological research we conducted preclinical biomechanical testing and tested the feasibility of the clinical approach. We made injectability studies and mechanical testing of cadaveric discs loaded with microcarriers as a feedback to the biological development stage and as forward planning of the clinical strategy. Further, we moved from an in vitro study to a clinical IVD regeneration application in veterinary patients (large dogs), which have degenerative disc disease (DDD). Dogs with DDD are a valuable unused resource which offer the advantages not only of reduced animal experimentation but of being a realistic model, because of the right combination of age, genetic predisposition and disc biochemistry. Diagnostics and outcome evaluation of veterinary patients (MRI of disc height, functional and neurological tests) which closely resembles that of the human condition and human clinical trials were conducted. These showed that the therapy was generally safe and the dogs had good clinical recovery. The problem was that significant MRI changes (increase of disc height or water content) which can confirm that the clinical recovery is due to the stem cell therapy were absent. Going back to the laboratory data, it was obvious that the MSC would not differentiate without differentiation factors and the hope to find these factors within already degenerated discs might have been too optimistic. The MRI state of the patient’s vertebral end plates - important gates of nutrition and waste removal was another variable which we didn’t measure. Our hypothesis is that mesenchymal stem cell therapy for intervertebral disc regeneration is within reach. In order to be successful we need to introduce the following improvements: On the biology side to develop further microcarriers which have on the surface covalently bound proteins or peptides. To test their properties in vitro and then to validate their injectability, extrusion and disc height restoration by biomechanical testing. To address this problem we will use two methods for covalent binding of growth and differentiation factors to the microcarriers. Finally we will again prove safety and efficiency in veterinary patients. We also want to introduce an improved disc imaging based on gadolinium contrast enhanced MRI, which will allow us to see also changes in the vertebral endplates, a possible source of degenerative changes. Possibly selecting patients with functional endplates can improve the outcome which can be seen by MRI. These results will give insights in the interactions needed to translate stem cell research into clinical practice and will be a strong foundation for a human clinical trials.