Studies of the in vivo bioresorption rate of composite filaments on the basis of polylactide filled with chitin nanofibrils or silver nanoparticles

Abstract

The rates of in vivo bioresorption of composite monofilaments based on polylactide (PLA) containing chitin nanofibrils of two types (pure chitin (CN) or chitin modified with poly(ethylene glycol) (CN-PEG)) or silver nanoparticles stabilized with poly(N-vinylpyrrolidone) (Poviargol) were studied. The in vivo bioresorption rate and its dependence on the degree of orientational drawing of the samples (which varied from 1 in non-oriented samples to 4 in oriented samples) were investigated up to 12 months after implantation. Bioresorption of the samples was monitored using differential scanning calorimetry, scanning electron microscopy, and mechanical tests. Using the differential scanning calorimetry (DSC) method, it was shown that there is a gradual decrease in molecular weight due to a decrease in the temperatures of phase transitions and changes in peak shapes. It has also been shown that the addition of fillers containing water-soluble polymers accelerates the bioresorption of composite sutures. A thread made from pure PLA lost half its strength by the 9th month of implantation, whereas for threads with the addition of CNPEG or Poviargol, this happened after 3.5 months. This causes leaching of water-soluble agents and changes in the supramolecular structure of the filament. This study shows the promise of using these composite threads as a suture material.

Keywords

• chitin
• poly(lactic acid)
• fiber
• fiber spinning
• morphology
• biomaterials
• antimicrobial properties
• degradation
• implant testing
• medical device