Synergistic Interactions of a Synthetic Lubricin-Mimetic with Fibronectin for Enhanced Wear Protection

Abstract

Lubricin (LUB), a major mucinous glycoprotein of mammalian synovial fluids, is believed to provide excellent lubrication to cartilage surfaces. Consequently, when joint disease or replacement leads to increased friction and surface damage in the joint, robust synthetic LUB alternatives that could be used therapeutically to improve lubrication and surface protection are needed. Here, we report the characterization of a lubricating multiblock bottlebrush polymer whose architecture was inspired by LUB, and we investigate the role of fibronectin (FN), a glycoprotein found in the superficial zone of cartilage, in mediating the tribological properties of the polymer upon shear between mica surfaces. Our surface forces apparatus (SFA) normal force measurements indicate that the lubricin-mimetic (mimLUB) could be kept anchored between mica surfaces, even under high contact pressures, when an intermediate layer of FN was present. Additional SFA friction measurements show that FN would also extend the wearless friction regime of the polymer up to pressures of 3.4 MPa while ensuring stable friction coefficients (μ ≈ 0.28). These results demonstrate synergistic interactions between mimLUB and FN in assisting the lubrication and wear protection of ideal (mica) substrates upon shear. Collectively, these findings suggest that our proposed mimLUB might be a promising alternative to LUB, as similar mechanisms could potentially facilitate the interaction between the polymer and cartilage surfaces in articular joints and prosthetic implants in vivo.

Glycosaminoglycan and Proteoglycan Biotherapeutics in Articular Cartilage Protection and Repair Strategies: Novel Approaches to Visco‐supplementation in Orthobiologics

“…The attached interactive binding peptides on mLUB15 equip it with interactive properties with synovial fluid components which promote boundary lubrication . mLUB15 displayed synergistic properties with fibronectin, its interactive properties provided by the HA and type II collagen binding peptides ensure consistent mLUB15 localization in squeeze films at the articular surface even under high pressure conditions.…”

An Accelerated Wound‐Healing Surgical Suture Engineered with an Extracellular Matrix

“…[ 14 ] Interestingly, FN is also known to have a lubricating property when combined with synovial fluid components. [ 15 ]…”

Two compartment pharmacokinetic model describes the intra‐articular delivery and retention of rhprg4 following ACL transection in the Yucatan mini pig

“…Five different research groups have tested native, recombinant human lubricin (rhPRG4) or lubricin mimic biomolecules by re‐introducing these into rodent joints after injury in the effort to retard cartilage loss. The inflammation associated with meniscal and ACL injuries is thought to downregulate PRG4 expression .…”