Catalyst Selection for Body-Temperature Curable Polyurethane Networks from Poly(δ-Decalactone) and Lysine...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Orthopedic Surgery

Background:

• Meniscus degradation due to aging, injury, or overuse causes pain and necessitates surgical replacement.
• Current surgical meniscus replacement carries risks of infection and complications from open wounds.
• Injectable polyurethane-based joint fillers offer a less invasive alternative.

Purpose of the Study:

• To synthesize a biocompatible, injectable polyurethane for meniscus replacement.
• To investigate catalysts for rapid in vivo crosslinking of the polyurethane.
• To evaluate the properties of the resulting polyurethane elastomer for joint filler applications.

Main Methods:

• Synthesized a polyurethane prepolymer using poly(δ-decalactone)triol and Lysine diisocyanate.
• Performed ¹H NMR kinetic studies to assess catalyst activity for alcohol/isocyanate addition at body temperature.
• Monitored isocyanate conversion and characterized the final polyurethane elastomer's mechanical and swelling properties.

Main Results:

• Stannous octoate demonstrated the highest catalytic activity, achieving 92% conversion with primary alcohols and 80% with secondary alcohols.
• Stannous octoate showed similar reactivity towards primary (49%) and secondary (47%) isocyanates.
• The resulting polyurethane elastomer exhibited an elastic modulus of 519 kPa and a low swelling index (<3% in PBS).

Conclusions:

• Stannous octoate is an effective catalyst for rapid polyurethane crosslinking.
• The synthesized polyurethane elastomer possesses suitable properties for injectable joint filler applications.
• This approach offers a promising, less invasive alternative to traditional meniscus surgery.