Drug Delivery and Translational Research

, Volume 9, Issue 1, pp 123–130 | Cite as

Influence of PEG coating on the biodistribution and tumor accumulation of pH-sensitive liposomes

  • Shirleide Santos Nunes
  • Renata Salgado Fernandes
  • Carolina Henriques Cavalcante
  • Isabela da Costa César
  • Elaine Amaral Leite
  • Sávia Caldeira Araújo Lopes
  • Alice Ferretti
  • Domenico RubelloEmail author
  • Danyelle M. Townsend
  • Mônica Cristina de Oliveira
  • Valbert Nascimento Cardoso
  • André Luís Branco de BarrosEmail author
Original Article


Liposomes are lipid vesicles widely used as nanocarriers in targeted drug delivery systems for therapeutic and/or diagnostic purposes. A strategy to prolong the blood circulation time of the liposomes includes the addition of a hydrophilic polymer polyethylene glycol (PEG) moiety onto the surface of the vesicle. Several studies claim that liposome PEGylation by a single chain length or a combination of PEG with different chain lengths may alter the liposomes’ pharmacokinetic properties. Therefore, the purpose of this study was to evaluate the influence of PEG on the biodistribution of pH-sensitive liposomes in a tumor-bearing animal model. Three liposomal formulations (PEGylated or not) were prepared and validated to have a similar mean diameter, monodisperse distribution, and neutral zeta potential. The pharmacokinetic properties of each liposome were evaluated in healthy animals, while the biodistribution and scintigraphic images were evaluated in tumor-bearing mice. High tumor-to-muscle ratios were not statistically different between the PEGylated and non-PEGylated liposomes. While PEGylation is a well-established strategy for increasing the blood circulation of nanostructures, in our study, the use of polymer coating did not result in a better in vivo profile. Further studies must be carried out to confirm the feasibility of the non-PEGylated pH-sensitive liposomes for tumor treatment.


Liposomes Tumor targeting PEGylation Drug delivery 


Funding information

We wish to thank Pro-Reitoria de Pesquisa (UFMG), Comissão Nacional de Energia Nuclear (CNEN), Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for their financial support and fellowships.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Controlled Release Society 2018

Authors and Affiliations

  • Shirleide Santos Nunes
    • 1
  • Renata Salgado Fernandes
    • 1
  • Carolina Henriques Cavalcante
    • 1
  • Isabela da Costa César
    • 1
  • Elaine Amaral Leite
    • 1
  • Sávia Caldeira Araújo Lopes
    • 1
  • Alice Ferretti
    • 2
  • Domenico Rubello
    • 2
    Email author
  • Danyelle M. Townsend
    • 3
  • Mônica Cristina de Oliveira
    • 1
  • Valbert Nascimento Cardoso
    • 1
  • André Luís Branco de Barros
    • 1
    • 4
    Email author
  1. 1.Faculdade de FarmáciaUniversidade Federal de Minas GeraisBelo HorizonteBrazil
  2. 2.Department of Nuclear Medicine, Radiology, Neuroradiology, Medical Physics, Clinical Laboratory, Microbiology, Pathology, Trasfusional MedicineSanta Maria della Misericordia HospitalRovigoItaly
  3. 3.Department of Drug Discovery and Pharmaceutical SciencesMedical University of South CarolinaCharlestonUSA
  4. 4.Faculty of PharmacyFederal University of Minas GeraisBelo HorizonteBrazil

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