New cosurface capacitive stimulators for the development of active osseointegrative implantable devices

Abstract

Non-drug strategies based on biophysical stimulation have been emphasized for the treatment and prevention of musculoskeletal conditions. However, to date, an effective stimulation system for intracorporeal therapies has not been proposed. This is particularly true for active intramedullary implants that aim to optimize osseointegration. The increasing demand for these implants, particularly for hip and knee replacements, has driven the design of innovative stimulation systems that are effective in bone-implant integration. In this paper, a new cosurface-based capacitive system concept is proposed for the design of implantable devices that deliver controllable and personalized electric field stimuli to target tissues. A prototype architecture of this system was constructed for in vitro tests, and its ability to deliver controllable stimuli was numerically analyzed. Successful results were obtained for osteoblastic proliferation and differentiation in the in vitro tests. This work provides, for the first time, a design of a stimulation system that can be embedded in active implantable devices for controllable bone-implant integration and regeneration. The proposed cosurface design holds potential for the implementation of novel and innovative personalized stimulatory therapies based on the delivery of electric fields to bone cells.

Natural and Eco-Friendly Materials for Triboelectric Energy Harvesting

“…Energy harvesting is a global area of research that includes the development of suitable methods of environmental energy collection, selection of materials, and customization of harvester designs, so that harvesters can operate over long periods of time with reduced intermittency and impact on environment, while ensuring low production and ecological costs. Many transduction mechanisms for energy harvesting have already been developed, and many designs of harvesting devices have been provided for a wide range of applications from small-to large-scale powering [1][2][3][4][5][6][7]. A few years ago, the interest of researchers was attracted by the triboelectric effect, by which electricity is produced due to mechanical friction between two bodies in a motion [8,9].…”

Altering the Course of Technologies to Monitor Loosening States of Endoprosthetic Implants

“…The relevant deterioration risk of cemented fixations in the mid and long-term also supports the decision-making in favor of the bone-implant interface [20]. Nevertheless, the uncemented fixation is more prone to induce bone loss due to stress shielding, a mechanical phenomenon resulting from different mechanical stimuli patterns delivered to the periprosthetic bone stock occurring after implant insertion [18,20]. Revision rates related to stress shielding-induced bone loss can exceed 50%, with incidences confirming implant loosening among the most common causes indicating bone replacement [1,21].…”

“…Besides, surgical revisions are usually more complex and significantly invasive, and the probability to undergo a second revision is five-to sixfold higher after the first revision [16,17]. An effective implant technology must then be developed with ability to fulfill the highly demanding lifetime requirements, ideally to eliminate or reduce the need of revision surgery [1,3,18].…”

“…Although these methods are considered accurate techniques to detect loosening states of both cementeless and cemented implants, the clinical follow-up can only be carried out in clinical laboratories, and thus the monitoring cannot be established throughout the daily life of patients. However, future personalized medicine requires technology innovation to trigger the development of advanced implantable devices to simultaneously perform intensive monitoring and actuation operations, to avoid implant failures [18,29,30]. This new technological trend is emerging to implement multifunctional and intelligent orthopedic implants comprising feedback control systems with the ability to enhance bone growth when loosening states are detected [21,29].…”

Immune-to-Detuning Wireless In-Body Platform for Versatile Biotelemetry Applications

“…In-body devices allow for continuous monitoring of various physiological parameters, namely intracorporal temperature, pressure, pH, glucose, hormone, antibody levels, endoscopic imagery, and so on. Moreover, implantable devices are a promising platform for therapeutic actuation using instrumented active implants [5], neural stimulators [6], and so on.…”