Challenges for the self-assembly of poly(Ethylene glycol)-poly(lactic acid) (PEG-PLA) into polymersomes: beyond the theoretical paradigms

Alexsandra Conceição Apolinário, Monika S. Magoń, Adalberto Pessoa Jr., Carlota de Oliveira Rangel-Yagui*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Polymersomes (PL), vesicles formed by self-assembly of amphiphilic block copolymers, have been described as promising nanosystems for drug delivery, especially of biomolecules. The film hydration method (FH) is widely used for PL preparation, however, it often requires long hydration times and commonly results in broad size distribution. In this work, we describe the challenges of the self-assembly of poly (ethylene glycol)-poly(lactic acid) (PEG-PLA) into PL by FH exploring different hydrophilic volume fraction (f) values of this copolymer, stirring times, temperatures and post-FH steps in an attempt to reduce broad size distribution of the nanostructures. We demonstrate that, alongside f value, the methods employed for hydration and post-film steps influence the PEG-PLA self-assembly into PL. With initial FH, we found high PDI values (>0.4). However, post-hydration centrifugation significantly reduced PDI to 0.280. Moreover, extrusion at higher concentrations resulted in further improvement of the monodispersity of the samples and narrow size distribution. For PL prepared at concentration of 0.1% (m/v), extrusion resulted in the narrower size distributions corresponding to PDI values of 0.345, 0.144 and 0.081 for PEG45-PLA69, PEG114-PLA153 and PEG114-PLA180, respectively. Additionally, we demonstrated that copolymers with smaller f resulted in larger PL and, therefore, higher encapsulation efficiency (EE%) for proteins, since larger vesicles enclose larger aqueous volumes.

Original languageEnglish
Article number373
Number of pages16
Issue number6
Publication statusPublished - 26 May 2018


  • Amphiphilic block copolymers
  • Polymeric vesicles
  • Post-film hydration steps
  • Self-aggregated nanostructures


Dive into the research topics of 'Challenges for the self-assembly of poly(Ethylene glycol)-poly(lactic acid) (PEG-PLA) into polymersomes: beyond the theoretical paradigms'. Together they form a unique fingerprint.

Cite this