Multidimensional mass spectrometry characterization of isomeric biodegradable polyesters

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Poly(propylene fumarate) (PPF) is a biodegradable polyester copolymer.
• PPF is suitable as an inert, cross-linkable scaffold material for bone tissue engineering.
• PPF is synthesized via isomerization of poly(propylene maleate).

Purpose of the Study:

• To characterize the composition, end groups, chain connectivity, and isomeric purity of poly(propylene maleate) and poly(propylene fumarate).
• To validate the synthesis and isomerization process for producing well-defined PPF oligomers.

Main Methods:

• Multidimensional mass spectrometry (MS): Matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI).
• Tandem mass spectrometry (MS/MS) fragmentation and ion mobility mass spectrometry (IM-MS).

Main Results:

• The polymerization catalyst is confirmed to be incorporated into the polymer chain as the initiating end group.
• The isomerization of poly(propylene maleate) to poly(propylene fumarate) using an amine base proceeds with quantitative yield.
• Hydrolytic degradation does not affect the double bond geometry of either polymer chain.

Conclusions:

• Advanced mass spectrometry techniques provide comprehensive characterization of PPF and its precursor.
• The synthesis and isomerization process yields high-purity PPF suitable for bone tissue engineering applications.
• PPF exhibits stable double bond geometry, crucial for its performance as a scaffold material.