Preparation of monodisperse polylactide microspheres by dispersion polymerization using a polymeric stabilizer with...

Area of Science:

• Polymer Chemistry
• Materials Science
• Nanotechnology

Background:

• Poly(D,L-lactide) (PDLLA) is a biodegradable polymer widely used in biomedical applications.
• Controlling the size and distribution of PDLLA microspheres is crucial for applications like drug delivery.
• Existing methods for synthesizing PDLLA microspheres can be complex and may result in broad particle size distributions.

Purpose of the Study:

• To develop a method for synthesizing monodisperse poly(D,L-lactide) (PDLLA) microspheres.
• To investigate the use of a synthetic polymeric stabilizer, poly[(dodecyl methacrylate)-co-(2-hydroxyethyl methacrylate)] (P(DMA-co-HEMA)), in dispersion polymerization.
• To characterize the size, distribution, and structural properties of the synthesized PDLLA microspheres.

Main Methods:

• Dispersion polymerization of D,L-lactide initiated by hydroxy groups of P(DMA-co-HEMA) in a xylene/heptane solvent system.
• Polymerization conducted at 368 K for 3 hours.
• Particle size and diameter distribution analyzed using dynamic light scattering (DLS).

Main Results:

• Monodisperse PDLLA microspheres were successfully prepared with a particle diameter of 3.9 µm.
• The coefficient of variation for the diameter distribution was 4.3%, indicating high uniformity.
• Dynamic light scattering measurements revealed the formation of a micellar structure between P(DMA-co-HEMA) and the PDLLA-grafted copolymer in solution.

Conclusions:

• A novel and effective pseudoanionic dispersion polymerization method was established for producing highly monodisperse PDLLA microspheres.
• The synthetic polymeric stabilizer P(DMA-co-HEMA) plays a crucial role in controlling particle size and uniformity.
• The observed micellar structure suggests potential for self-assembly and further functionalization of the PDLLA microspheres.