Pharmaceutical Research

, 35:171 | Cite as

Combined Used of Rheology and LF-NMR for the Characterization of PVP-Alginates Gels Containing Liposomes

  • Giulia Fanesi
  • Michela Abrami
  • Francesca Zecchin
  • Irina Giassi
  • Elena Dal Ferro
  • Anja Boisen
  • Gabriele Grassi
  • Paolo Bertoncin
  • Mario Grassi
  • Paolo Marizza
Research Paper
Part of the following topical collections:
  1. 6th World Conference on Physico-Chemical Methods in Drug Discovery and Development & 3rd World Conference on ADMET and DMPK



This paper is based on the characterization of the rheological and Low Field NMR (LF-NMR) properties of an interpenetrated hydrogel made up by poly(N-vinyl-2-pyrrolidone) and sodium alginate. The final aim is to use the hydrogel as a delivery matrix for liposomes, widely used tools in the drug delivery field.


Rheology, LF-NMR, TEM, cryo-TEM, confocal laser scanning microscopy and release test were employed to characterize the interpenetrated hydrogel. Different theoretical approaches such as Flory, Chui, Scherer and Schurz theories were used to interpret the experimental results.


We found that the crosslinking mechanisms of the two polymers produced an anti-synergistic effect on the final mechanical properties of the interpenetrated hydrogel. Instead of creating a continuous network, alginate formed isolated, cross-linked, clusters embedded in a continuous network of poly(N-vinyl-2-pyrrolidone). Additionally, gel structure significantly influenced liposome delivery.


The rheological and LF-NMR characterization were confirmed and supported by the independent techniques TEM, cryo-TEM and release tests Thus, our findings reiterate the potentiality of both rheology and LF-NMR for the characterisation of soft materials such as interpenetrated polymeric networks.

Key words

Gel LF-NMR liposomes delivery rheology TEM 



Confocal fluorescence


Drug delivery system


Dynamic Light Scattering






Frequency sweep test




Interpenetrated network


Low Field Nuclear Magnetic Resonance


Laser Scanning Microscope






Stress sweep test


Transmission electron microscopy


Acknowledgments and Disclosures

This work was supported by the Italian Ministry of Education (PRIN 2010–11 (20109PLMH2)), by Fondo di Ateneo FRA 2016 – Trieste University, BIOFLUO project, POR FESR 2014–2020, FVG, Italy. The authors would like to acknowledge the Danish National Research Foundation (DNRF122) and Villum Fonden (Grant No. 9301) for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics (IDUN). Authors would like to acknowledge Prof. Leticia Hosta-Rigau and Dr. Maria Godoy Gallardo for the interesting discussions and the valuable inputs given to the investigation.

Supplementary material

11095_2018_2427_MOESM1_ESM.docx (21 kb)
ESM 1 (DOCX 20 kb)


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Giulia Fanesi
    • 1
  • Michela Abrami
    • 2
  • Francesca Zecchin
    • 2
  • Irina Giassi
    • 2
  • Elena Dal Ferro
    • 1
  • Anja Boisen
    • 1
  • Gabriele Grassi
    • 3
  • Paolo Bertoncin
    • 4
  • Mario Grassi
    • 2
  • Paolo Marizza
    • 1
  1. 1.Department of Micro- and NanotechnologyTechnical University of Denmark (DTU)Kongens LyngbyDenmark
  2. 2.Department of Engineering and ArchitectureUniversity of TriesteTriesteItaly
  3. 3.Department of Life Sciences, Cattinara HospitalUniversity of TriesteTriesteItaly
  4. 4.Department of Life SciencesUniversity of TriesteTriesteItaly

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