Injectable and biodegradable piezoelectric hydrogel for osteoarthritis treatment

TLDR

Osteoarthritis affects millions worldwide, yet current analgesic or anti‑inflammatory treatments only alleviate symptoms. We present an injectable, biodegradable piezoelectric hydrogel designed to drive cartilage healing. The hydrogel consists of short electrospun poly‑L‑lactic acid nanofibers embedded in a collagen matrix and self‑produces localized electrical cues under ultrasound activation. In vitro, the ultrasound‑activated hydrogel promotes stem‑cell migration and TGF‑β1 secretion, enhancing chondrogenesis, while in vivo it increases subchondral bone formation, improves hyaline‑cartilage structure and mechanical properties near native cartilage, and shows promise for broader tissue regeneration.

Abstract

Osteoarthritis affects millions of people worldwide but current treatments using analgesics or anti-inflammatory drugs only alleviate symptoms of this disease. Here, we present an injectable, biodegradable piezoelectric hydrogel, made of short electrospun poly-L-lactic acid nanofibers embedded inside a collagen matrix, which can be injected into the joints and self-produce localized electrical cues under ultrasound activation to drive cartilage healing. In vitro, data shows that the piezoelectric hydrogel with ultrasound can enhance cell migration and induce stem cells to secrete TGF-β1, which promotes chondrogenesis. In vivo, the rabbits with osteochondral critical-size defects receiving the ultrasound-activated piezoelectric hydrogel show increased subchondral bone formation, improved hyaline-cartilage structure, and good mechanical properties, close to healthy native cartilage. This piezoelectric hydrogel is not only useful for cartilage healing but also potentially applicable to other tissue regeneration, offering a significant impact on the field of regenerative tissue engineering.