AQP3-liposome@GelMA promotes overloaded-induced degenerated disc regeneration via IBSP/ITG αVβ3/AKT pathway.

Medical and conservative treatments for intervertebral disc degeneration (IDD) primarily focus on alleviating symptoms. However, effective curative therapies that promote disc regeneration remain lacking. Recent advancements in disc repair materials offer a potential solution, but identifying effective cytokines for regeneration and developing efficient drug delivery systems are crucial for success. This study demonstrated a negative correlation between AQP3 expression levels and the extent of disc degeneration induced by mechanical overload, as evidenced in both in vivo and in vitro models, suggesting that AQP3 is a key regulator of intervertebral disc (IVD) homeostasis. Moreover, the overexpression of AQP3 or exogenous AQP3 protein significantly repaired degenerated IVDs. As a membrane protein, exogenous AQP3 is challenging for cells to recognize and internalize. To address this issue, we designed liposomes to encapsulate AQP3 and incorporated them into GelMA (AQP3-lipo@GelMA) for targeted repair of IDD resulting from high mechanical pressure. The encapsulation of AQP3 in liposomes improved cellular recognition and uptake, thereby enhancing its functionality at the cell membrane. Additionally, AQP3 within this material inhibited the binding of integrins to sialic acid-binding proteins (IBSP), which subsequently reduced the expression of the downstream integrin αVβ3. This cascade effect indirectly activated the AKT pathway, promoting the survival of NP cells. In vivo experiments, we found that AQP3-lipo@GelMA had an efficient function of repairing degenerated intervertebral disc. This study introduced AQP3-lipo@GelMA as a promising material for clinical applications in IVD repair.