Electrical stimulation for cartilage tissue engineering - A critical review from an engineer's perspective
Julius Zimmermann, Abdul Razzaq Farooqi, Ursula van Rienen
Abstract
Cartilage has a limited intrinsic healing capacity. Hence, cartilage degradation and lesions pose a huge clinical challenge, particularly in an ageing society. Osteoarthritis impacts a significant number of the population and requires the development of repair and tissue engineering methods for hyaline articular cartilage. In this context, electrical stimulation has been investigated for more than 50 years already. Yet, no well-established clinical therapy to treat osteoarthritis by means of electrical stimulation exists. We argue that one reason is the lack of replicability of electrical stimulation devices from a technical perspective together with lacking hypotheses of the biophysical mechanism. Hence, first, the electrical stimulation studies reported in the context of cartilage tissue engineering with a special focus on technical details are summarized. Then, an experimental and numerical approach is discussed to make the electrical stimulation experiments replicable. Finally, biophysical hypotheses have been reviewed on the interaction of electric fields and cells that are relevant for cartilage tissue engineering. With that, the aim is to inspire future research to enable clinical electrical stimulation therapies to fight osteoarthritis.