Poly(ester amide)s from Poly(ethylene terephthalate) Waste for Enhancing Bone Regeneration and Controlled Release

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Recycling poly(ethylene terephthalate) (PET) waste is crucial for sustainability.
• Developing novel biodegradable polymers with tunable properties is essential for tissue engineering applications.

Purpose of the Study:

• To synthesize and characterize novel poly(ester amide)s (PEAs) from PET waste.
• To investigate the influence of dicarboxylic acid chain length on PEA properties, degradation, and osteogenic potential.

Main Methods:

• Synthesis of PEAs using bis(2-hydroxy ethylene) terephthalamide derived from PET waste.
• Characterization using Fourier transform infrared spectroscopy (FTIR), 1H Nuclear Magnetic Resonance (NMR), Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA).
• In vitro degradation, dye release, cytocompatibility, and osteogenic studies (Alizarin red staining, alkaline phosphatase expression, real-time PCR).

Main Results:

• PEAs were successfully synthesized and characterized, confirming the presence of ester and amide linkages.
• Glass transition temperature decreased, while modulus and hydrophobicity increased with longer dicarboxylic acid chain lengths.
• Degradation and release kinetics followed first-order and zero-order models, respectively, decreasing with increased chain length.
• Polymers exhibited minimal toxicity and significantly promoted osteogenesis, evidenced by increased calcium phosphate deposition and expression of osteogenic markers.

Conclusions:

• Tunable physical properties, degradation, and release kinetics of PEAs can be achieved by controlling monomer chain length.
• These novel PEAs demonstrate significant potential for organ regeneration and tissue engineering applications.
• The study highlights the development of cost-effective, biodegradable polymers from recycled materials for advanced biomedical applications.