Enhanced Chondrogenic Differentiation of Electrically Primed Human Mesenchymal Stem Cells for the Regeneration of Osteochondral Defects.

Mesenchymal stem cells (MSCs) offer a promising avenue for cartilage regeneration; however, their therapeutic efficacy requires substantial improvement. Cell priming using electrical stimulation (ES) is a promising approach to augmenting the therapeutic potential of MSCs and has shown potential for various regenerative applications. This study aimed to promote the ES-mediated chondrogenic differentiation of human MSCs and facilitate the repair of injured articular cartilage.

Enzymatically stable, non-cell adhesive, implantable polypyrrole/thiolated hyaluronic acid bioelectrodes for in vivo signal recording.

Implantable bioelectrodes have attracted significant attention for precise in vivo signal transduction with living systems. Conductive polymers, including polypyrrole (PPy), have been widely used as bioelectrodes due to their large surface areas, high charge injections, and versatilities for modification. Especially, several natural biopolymers, such as hyaluronic acid (HA), can be incorporated into conductive polymers to produce biomimetic electrodes with better biocompatibility.

Biomimetic polypyrrole/hyaluronic acid electrodes integrated with hyaluronidase inhibitors offer persistent electroactivity and resistance to cell binding.

Conductive polymers, including polypyrrole (PPy), have garnered much attention as bioelectrodes because of their high conductivity, low interfacial resistance, environmental stability, and biocompatibility. In particular, the introduction of high-molecular weight hyaluronic acid (HA) into PPy enables the fabrication of biomimetic and biocompatible electrodes (, PPy/HA) characterized by low biofouling. However, as HA is readily degraded by enzymes (, hyaluronidase (HAase)) in a biological milieu, PPy/HA substantially loses its original properties, including resistance to cell adhesion and electrical activity.