Preparation of poly(L-lactide)-based microspheres having a cationic or anionic surface using biodegradable...

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Poly(L-lactide) (PLLA) is a biodegradable polymer widely used in biomedical applications.
• Surface modification of PLLA microspheres is crucial for targeted drug delivery and tissue engineering.
• Developing effective surfactants for controlled microsphere fabrication remains a challenge.

Purpose of the Study:

• To synthesize novel polydepsipeptide-block-poly(L-lactide) copolymers for use as surfactants.
• To prepare poly(L-lactide)-based microspheres with tunable cationic or anionic surface charges.
• To investigate the effect of block copolymer concentration on microsphere surface properties and size.

Main Methods:

• Anionic ring-opening polymerization of L-lactide using protected polydepsipeptides as macroinitiators.
• Deprotection of side chains to introduce amino or carboxylic acid groups.
• Oil-in-water emulsion method for microsphere preparation using the synthesized block copolymers.
• Scanning electron microscopy (SEM) for microsphere size analysis.

Main Results:

• Successfully synthesized amphiphilic polydepsipeptide-block-poly(L-lactide) copolymers.
• Prepared PLLA microspheres with controllable cationic or anionic surface charges.
• Surface ionic group density increased with higher block copolymer feed.
• Microsphere diameter decreased with increasing block copolymer concentration.

Conclusions:

• Polydepsipeptide-block-poly(L-lactide) copolymers are effective surfactants for creating charged PLLA microspheres.
• This method allows for precise control over microsphere surface functionality and size.
• The developed microspheres hold potential for advanced biomedical applications requiring surface-specific interactions.