Long-Term Stability and Osteogenic Activity of Recycled Polysulfone-Calcium Silicate Bone Implants In Vitro

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Materials Recycling

Background:

• Polysulfone (PSF) is a high-performance plastic with potential for orthopedic implants, but requires enhanced osteogenesis.
• Long-term mechanical stability is crucial for load-bearing bone implants.
• Recycling PSF medical waste addresses environmental concerns and material scarcity.

Purpose of the Study:

• To upcycle polysulfone (PSF) medical waste into bone composites by incorporating osteogenic calcium silicate (CaSi).
• To evaluate the biostability and osteogenic potential of PSF-CaSi composites for orthopedic applications.

Main Methods:

• PSF medical waste was compounded with 10%, 20%, and 30% calcium silicate (CaSi).
• Composites were immersed in simulated body fluid (SBF) for 12 months at pH 7.4 and 5.0.
• Phase, morphology, weight loss, bending strength, and human mesenchymal stem cell (hMSC) osteogenic activity were assessed.

Main Results:

• PSF-CaSi composites exhibited manageable weight loss (~4%) after 12 months in SBF.
• Bending strength decreased with prolonged SBF exposure.
• CaSi incorporation positively influenced hMSC attachment, proliferation, alkaline phosphatase (ALP) levels, and calcium deposits, correlating with CaSi content.

Conclusions:

• The 20% CaSi-PSF composite demonstrates a favorable balance of biostability and osteogenic ability.
• This composite shows potential as a candidate material for load-bearing orthopedic implants.
• Upcycling PSF medical waste with CaSi offers a sustainable approach to developing enhanced bone implant materials.