Fabrication of ultrahigh-molecular-weight polyethylene porous implant for bone application

Abstract

Porous implants play a crucial role in allowing ingrowth of host connective tissue and thereby help in keeping the implant in its place. With the aim of mimicking the microstructure of natural extracellular matrix, ultrahigh-molecular-weight polyethylene (UHMWPE) porous samples with a desirable pore size distribution were developed by combining thermally induced phase separation and salt leaching techniques. The porous UHMWPE samples consisted of a nanofibrous UHMWPE matrix with a fibre diameter smaller than 500 nm, highly interconnected, with a controllable pore diameter from nanoscale to 300 µm. Moreover, a porous UHMWPE sample was also developed as a continuous and homogeneous coating onto the UHMWPE dense sample. The dense/porous UHMWPE sample supported human foetal osteoblast 1.19 cell line proliferation and differentiation, indicating the potential of porous UHMWPE with a desirable pore size distribution for bone application. An osseointegration model in the sheep revealed substantial bone formation within the pore layer at 12 weeks via SEM evaluation. Ingrown bone was more closely opposed to the pore wall when compared to the dense UHMWPE control. These results indicate that dense/porous UHMWPE could provide improved osseointegration while maintaining the structural integrity necessary for load-bearing orthopaedic application.

Porous Ultrahigh Molecular Weight Polyethylene/Functionalized Activated Nanocarbon Composites with Improved Biocompatibility

“…Porous permeation is one of the most important characteristics in natural articular cartilage models. A low P v value can easily lead to poor fluid flow in cartilage, but a high P v value can easily lead to cartilage brittleness, resulting in fractures, cartilage loss, and other diseases [ 10 , 11 , 12 ]. For health reasons, the P v values of cartilaginous materials should be as close as possible to that of natural cartilage, which must be between 30% and 47% [ 15 , 16 , 37 , 38 ].…”

“…After treatment, MTT solution (0.5 mL) was added to each well and cultured at 37 °C for 3–4 h. A sample of 1 mL of dimethyl sulfoxide was dropped into each well to dissolve intracellular formazan. Absorption was recorded using a micro plate reader at 570 nm [ 11 ]. Cell viability percentage was determined using the equation: CV = OD m / OD r × 100 where OD m and OD r is the optical density of the treated and untreated cells, respectively.…”

“…The latest technologies in the field of joint replacement include bone integration of artificial joints, improvements in bone replacement materials, implants, and rehabilitation devices, and joint replacement technology based on dynamic bone synthesis models [ 5 , 6 ]. New bone materials, such as PVA-H [ 7 , 8 , 9 ] and UHMWPE, with a high modulus of elasticity, biocompatibility, and mechanical properties, were studied systematically and in depth [ 10 , 11 , 12 ]. Ultra-high molecular weight polyethylene (UHMWPE) is the most common material used for the artificial joint bearing component, with the advantage of unique characteristics and favorable properties, such as biocompatibility, chemical stability, high wear resistance, and low friction [ 10 , 11 , 12 , 13 , 14 ].…”

“…New bone materials, such as PVA-H [ 7 , 8 , 9 ] and UHMWPE, with a high modulus of elasticity, biocompatibility, and mechanical properties, were studied systematically and in depth [ 10 , 11 , 12 ]. Ultra-high molecular weight polyethylene (UHMWPE) is the most common material used for the artificial joint bearing component, with the advantage of unique characteristics and favorable properties, such as biocompatibility, chemical stability, high wear resistance, and low friction [ 10 , 11 , 12 , 13 , 14 ]. However, the low hydrophilicity and mechanics properties of UHMWPE easily lead to artificial joint replacement failure [ 15 , 16 ].…”

Fabrication of light‐weight ultrahigh molecular weight polyethylene films with hybrid porous structure and the thermal insulation properties

“…The fabrications of various UHMWPE porous materials have been reported, but they are usually focused on the separation efficiency, biocompatibility, and tribological properties, because these UHMWPE porous materials are employed in the water treatment 18,19 and bioengineering fields. 20,21 Moreover, due to the high viscosity and difficult processing of UHMWPE, it is arduous to adjust the porosity by traditional methods, such as uniaxial or biaxial tensile method, thermally induced phase separation method or physical leaching method. And the effect of porosity and pore structure on thermal conductivity of UHMWPE materials is still unclear.…”