Hometown:
Langenthal / St. Moritz, Switzerland

Education:
VMD, University of Pennsylvania, 1996
B.S., Schweizerische Alpine Mittelschule Davos, 1986

Areas of Expertise:
Large animal surgery, orthopaedic large animal models Areas of Special Interest:
Orthopaedic tissue engineering and biomaterials; intervertebral disc biology, injury and novel approaches to therapy; design and development of minimally invasive surgical approaches to the musculoskeletal system; drug delivery systems for local antimicrobial therapy.

Research Description:
Permanent pain, disability and joint dysfunction are the typical consequences of skeletal afflictions (trauma, osteoarthritis, osteoporosis, complex fracture healing, bone tumours, and low back pain). The success of surgical treatment such as osteotomy, perichondral grafting, interposition arthroplasty, joint replacement, or spinal fusion is limited. A biological approach to bone, cartilage, and intervertebral disc injuries exploits the possibility of using tissues generated in vitro, by cells seeded onto suitable scaffolds, and then implanted in vivo to regenerate a functional tissue (tissue engineering). There is an increasing need of suitable large animal models to evaluate the long-term response of orthopaedic biomaterials and tissue-engineered products in vivo.
Our research focuses on the development of orthopaedic animal models to study the response and interaction of these soft and hard tissues to various biomaterials and tissue-engineered products. In vitro and in vivo models of healthy tissues are studied providing information to design models mimicking specific degenerative processes to study injury, degeneration and healing of specific tissues in presence of biomaterials.
The goal is to assist clinicians and engineers alike in a modular manner, integrating the existing animal health care facilities of the University of Pennsylvania New Bolton Center and U Penn Research Core for: project design, planning and management, technique development, surgery, anesthesia, animal care, data collection and processing, and presentation and publication of study results.

Ongoing Research Projects
Intervertebral disc disease –

Tissue Engineering of the intervertebral disc:
Multidisciplinary collaboration with the Dept. of Orthopaedic Surgery University of Pennsylvania School of Medicine and the Dept. of Bioengineering of the University of Pennsylvania School of Engineering and Applied Sciences.
In this work we evaluate and model in vitro mechanics of ovine lumbar motion segments to study tissue function and the mechanisms for degeneration, injury and healing. In addition, understanding in vitro mechanical behavior of the disc will allow us to design a relevant large animal model to study in vivo behavior of degeneration, injury and healing to develop novel treatments.

Nucleus Pulposus Replacement Therapy:
Collaboration with the Department of Bioengineering of Drexel University.
In this work we focus on the development of minimally invasive surgical approaches to the lumbar spine and the required surgical instrumentarium and technology for nucleus pulposus therapy.

Ultrastructural analysis of nucleus pulposus tissue:
Morphological description and comparison of human, ovine and rodent nucleus pulposus cellular architecture

Diffusion of antibiotics from a biodegradable thermogelling chitosan system in vitro:
In this work we evaluate the in vitro efficacy of drug elution of specific antimicrobials from a biodegradable matrix. The next phase will evaluate this matrix loaded with a specific antimicrobial in an in vivo osteomyelitis model in sheep.

Articular cartilage repair using a porous bioactive substrate in an ovine model:
This work studies the short and long term effects of mosaicplasty of a critical size articular defect in the medial femoral condyle in sheep. Previous work has shown that our porous bioactive substrate favors the formation of articular cartilage as repair tissue in full thickness articular defects in a rabbit model.

Articular cartilage stiffness in selected equine joints – in vivo and in vitro baseline evaluation and data collection of cartilage stiffness with Artscan 200:
This work establishes the baseline data collection (mapping) for selected “normal” equine joints in the thoroughbred and standardbred racehorse. The goal is to provide a basis for comparison of articular cartilage stiffness data when evaluating joints in the orthopaedic equine patient during arthroscopic surgery.