Effect of Processing Technology on the Degradation Behavior of Poly(p-dioxanone) Cog Threads

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Medical Device Engineering

Background:

• Poly(p-dioxanone) (PPDO) cog threads are integral to facial rejuvenation procedures.
• Fabrication methods like injection molding, compression molding, and cutting impart distinct thermal and mechanical histories to PPDO threads.
• The impact of these processing-induced structural variations on PPDO thread degradation and clinical efficacy requires thorough investigation.

Purpose of the Study:

• To elucidate the influence of three distinct processing techniques on the in vitro degradation characteristics and mechanical integrity of PPDO cog threads.

Main Methods:

• PPDO cog threads fabricated via injection molding, compression molding, and cutting were subjected to in vitro degradation in 37°C phosphate-buffered saline (PBS) for 32 weeks.
• Key parameters monitored included mass loss rate, inherent viscosity, tensile strength, grasping force, and surface morphology via scanning electron microscopy (SEM).

Main Results:

• A two-stage degradation pattern was observed across all samples.
• Injection-molded threads (highest thermal processing) exhibited the most rapid degradation. Unheated, cut threads demonstrated superior molecular chain integrity and prolonged degradation resistance.
• Mechanical property analysis revealed that cut threads experienced slower initial tensile strength loss, while injection-molded threads showed a more pronounced decline in grasping force retention.

Conclusions:

• Processing technology critically dictates the degradation kinetics of PPDO cog threads.
• Strategic selection of fabrication methods allows for tailored degradation profiles, providing a scientific basis for optimizing cog thread choice in clinical settings.