Biomimetic cartilage-lubricating polymers regenerate cartilage in rats with early osteoarthritis

Brush-like biopolymers mimicking the lubrication properties of natural cartilage-binding complexes in articular joints enhance cartilage regeneration in a rat model of early osteoarthritis. The early stages of progressive degeneration of cartilage in articular joints are a hallmark of osteoarthritis. Healthy cartilage is lubricated by brush-like cartilage-binding nanofibres with a hyaluronan backbone and two key side chains (lubricin and lipid). Here, we show that hyaluronan backbones grafted with lubricin-like sulfonate-rich polymers or with lipid-like phosphocholine-rich polymers together enhance cartilage regeneration in a rat model of early osteoarthritis. These biomimetic brush-like nanofibres show a high affinity for cartilage proteins, form a lubrication layer on the cartilage surface and efficiently lubricate damaged human cartilage, lowering its friction coefficient to the low levels typical of native cartilage. Intra-articular injection of the two types of nanofibre into rats with surgically induced osteoarthritic joints led to cartilage regeneration and to the abrogation of osteoarthritis within 8 weeks. Biocompatible injectable lubricants that facilitate cartilage regeneration may offer a translational strategy for the treatment of early osteoarthritis.

Automated summary

Using brush-like biopolymers to mimic the lubrication properties of natural cartilage-binding complexes can enhance cartilage regeneration in a rat model of early osteoarthritis. The biomimetic nanofibers with added lubricin-like and lipid-like compounds show a high affinity for cartilage proteins and effectively lubricate damaged cartilage, leading to cartilage regeneration and the abrogation of osteoarthritis within 8 weeks. This approach may offer a translational strategy for the treatment of early osteoarthritis.