Advances in Clinical and Experimental Medicine

Title abbreviation: Adv Clin Exp Med
JCR Impact Factor (IF) – 2.1 (5-Year IF – 2.0)
Journal Citation Indicator (JCI) (2023) – 0.4
Scopus CiteScore – 3.7 (CiteScore Tracker 3.8)
Index Copernicus  – 171.00; MNiSW – 70 pts

ISSN 1899–5276 (print)
ISSN 2451-2680 (online)
Periodicity – monthly

Download original text (EN)

Advances in Clinical and Experimental Medicine

2015, vol. 24, nr 2, March-April, p. 219–226

doi: 10.17219/acem/40468

Publication type: original article

Language: English

Download citation:

  • BIBTEX (JabRef, Mendeley)
  • RIS (Papers, Reference Manager, RefWorks, Zotero)

The Conductivity and pH Values of Dispersions of Nanospheres for Targeted Drug Delivery in the Course of Forced Equilibrium Dialysis

Witold Musiał1,A,B,C,D,E,F, Janusz Pluta2,E,F, Tomasz Byrski2,B,F, Julija V. Valh3,B,F

1 Department of Physical Chemistry, Faculty of Pharmacy, Wroclaw Medical University, Poland

2 Department of Pharmaceutical Technology, Faculty of Pharmacy, Wroclaw Medical University, Poland

3 Laboratory for Chemistry and Environmental Protection, Engineering Materials and Design, Faculty of Mechanical Engineering, University of Maribor, Slovenia

Abstract

Background. In the available literature, the problem of pH and conductivity in FED is evaluated separately, and limited mainly to the final purity of the synthesized polymer. In this study data from conductivity and pH measurements were evaluated in the context of the structure of the macromolecule.
Objectives. The aim of the study was to evaluate the conductivity and pH of dispersions of nanospheres synthesized with the use of N-isopropyl acrylamide (NIPA) as the main monomer, N,N’-methylenebisacrylamide (MBA) as the cross-linker and acrylic acid (AcA) as the anionic comonomer during the purification of dispersions via forced equilibrium dialysis (FED).
Material and Methods. Six batches of nanospheres were obtained in the process of surfactant free precipitation polymerization (SFPP) under inert nitrogen. The conductivity and pH of the dispersions of nanospheres were measured at the beginning of FED and after finishing that process. The conductivity in the systems being studied decreased significantly in the process of FED. The initial values of conductivity ranged from 736.85 ± 8.13 μS × cm–1 to 1048.90 ± 67.53 μS × cm–1 After 10 days, when the systems being assessed gained stability in terms of conductivity level, the values of conductivity were between 4.29 ± 0.01 μS × cm–1 and 33.56 ± 0.04 μS × cm–1. The pH values inreased significantly after FED. The resulting pH was between 6.92 ± 0.07 and 8.21 ± 0.07, while the initial values were between 3.42 ± 0.23 μS × cm–1 and 4.30 ± 0.22 μS × cm–1.
Conclusion. Conductivity and pH measurements performed during purification via FED provide important information on the composition of the resulting nanospheres, including the functional groups embedded in the structure of the polymer in the course of the synthesis, as well as the purity of the structures. The presence of a cross-linker and acidic comonomer in the poly-N-isopropyl acrylamide (polyNIPA) macromolecule may be confirmed by both the pH and the conductivity measurements.
Conclusion. Adv Clin Exp Med 2015, 24, 2, 219–226

Key words

nanosphere, conductivity, pH, N-isopropyl acrylamide, polymer, surfactant free precipitation polymerization.

References (30)

  1. Oh JN, Lee DI, Park JM: Biopolymer-based microgels/nanogels for drug delivery applications. Prog Polym Sci 2009, 34, 12, 1261–1282.
  2. Oh JN, Drumright R, Siegwart DJ: The development of microgels/nanogels for drug delivery applications. Prog Polym Sci 2009, 33, 4, 448–477.
  3. Oh JN, Bencherif SA, Matyjaszewski K: Atom transfer radical polymerization in inverse miniemulsion: A versatile route toward preparation and functionalization of microgels/nanogels for targeted drug delivery applications. Polymer 2009, 50, 19, 4407–4423.
  4. Quan CY, Wei H, Shi Y: Fabrication of multifunctional shell cross-linked micelles for targeting drug release. Colloid Polym Sci 2011, 289, 5–6, 667–675.
  5. Lee L, Woo I, Cheong S: Synthesis of Poly(N-isopropylacrylamide)/Poly(ethyl-2-cyanoacrylate) Composite Hollow Particles. Macromol Res 2010, 18, 2, 208–211.
  6. Dai W, Zhang Y, Du Z: The pH-induced thermosensitive poly (NIPAAm-co-AAc-co-HEMA)-g-PCL micelles used as a drug carrier. J Mater Sci: Mater Medi 2010, 21, 6, 1881–1890.
  7. Mayo FR, Lewis FM: Copolymerization: I. A Basis for Comparing the Behavior of Monomers in Copolymerization; The Copolymerization of Styrene and Methyl Methacrylate. J Am Chem Soc 1944, 66, 9, 1594–1601.
  8. Zhou J, Wang G, Zou L: Viscoelastic Behavior and In Vivo Release Study of Microgel Dispersions with Inverse Thermoreversible Gelation. Biomacromolecules 2008, 9, 1, 142–148.
  9. Hoare T, Pelton R: Impact of Microgel Morphology on Functionalized Microgel−Drug Interactions. Langmuir 2008, 24, 3, 1005–1012.
  10. Hoare T, Pelton R: Charge-Switching, Amphoteric Glucose-Responsive Microgels with Physiological Swelling Activity. Biomacromolecules 2008, 9, 2, 733–740.
  11. Das M, Sanson N, Fava D: Microgels Loaded with Gold Nanorods: Photothermally Triggered Volume Transitions under Physiological Conditions. Langmuir 2007, 23, 1, 196–201.
  12. Joo MK, Park MH, Choi BG: Reverse thermogelling biodegradable polymer aqueous solutions. J Materials Chem 2009, 33, 19, 5891–5905.
  13. Musial W, Vincent B, Szumny A: Morphological characteristics of modified freeze-dried poly(N-isopropylacrylamide) microspheres studied by optical microscopy. SEM, and DLS. Chem Pap 2010, 64, 5, 602–612.
  14. Naha P: Preparation, characterization and ecotoxicological evaluation of four environmentally relevant species of N-isopropylacrylamide and N-isopropylacrylamide-co-N-tert-butylacrylamide copolymer nanoparticles. Aquat Toxicol 2009, 92, 3, 146–154.
  15. Chen G, Hoffman AS: A new temperatureand pH-responsive copolymer for possible use in protein conjugation. Macromol Chem Phys 1995, 195, 4, 1251–1259.
  16. Limayem I, Charcosset C, Fessi H: Purification of nanoparticle suspensions by a concentration/diafiltration process. Sep Purif Technol 2004, 38, 1, 1–9.
  17. Jassby D, Chae SR, Hendren Z: Membrane filtration of fullerene nanoparticle suspensions: Effects of derivatization, pressure, electrolyte species and concentration. J Colloid Interface Sci 2010, 346, 2, 296–302.
  18. Kim S, Marion M, Jeong BH: Crossflow membrane filtration of interacting nanoparticle suspensions. J Membr Sci 2006, 284, 1–2, 361–372.
  19. Yun KM, Hogan CJ Jr, Matsubayashi Y: Nanoparticle filtration by electrospun polymer fibers. Cheml Eng Sci 2007, 62, 17, 4751–4759.
  20. Mihaila R, Chang S, Wei AT: Lipid nanoparticle purification by Spin Centrifugation–Dialysis (SCD): A facile and high-throughput approach for small scale preparation of siRNA–lipid complexes. Int J Pharm 2011, 420, 1, 118–121.
  21. Ding Z, Chen G, Hoffman AS: Synthesis and purification of thermally sensitive oligomer-enzyme conjugates of poly(N-isopropylacrylamide)-trypsin. Bioconjugate Chem 1996, 7, 1, 121–126.
  22. Gao J, Frisken BJ: Cross-Linker-Free N-Isopropylacrylamide Gel Nanospheres. Langmuir 2003, 19, 13, 5212–5216.
  23. Gilanyi T, Varga I, Meszaros R: Interaction of Monodisperse Poly(N-isopropylacrylamide) Microgel Particles with Sodium Dodecyl Sulfate in Aqueous Solution. Langmuir 2001, 17, 16, 4764–4769.
  24. Yallapu MM, Vasir JK, Jain TK: Synthesis, Characterization and Antiproliferative Activity of Rapamycin-Loaded Poly(N-Isopropylacrylamide)-Based Nanogels in Vascular Smooth Muscle Cells. J Biomed Nanotechnol 2008, 4, 1, 16–24.
  25. Singh N, Lyon LA: Au Nanoparticle Templated Synthesis of pNIPAm Nanogels. Chem Mater 2007, 19, 4, 719–726.
  26. Ayame H, Morimoto N, Akiyoshi K: Self-Assembled Cationic Nanogels for Intracellular Protein Delivery. Bioconjugate Chemistry 2008, 19, 4, 882–890.
  27. Coates J: Interpretation of infrared spectra, a practical approach in “Encyclopedia of analytical chemistry”. Ed. Meyers RA, Wiley, Chichester-UK 2000, 10815–10837.
  28. Dušek K: Phase separation during the formation of three-dimensional polymers. J Polym Sci C, Pol Symp 1967, 16, 1289–1299.
  29. Dušek K: Quasichemical equilibrium approach to crosslinked polymer solutions. J Polym Sci C, Pol Symp 1967, 39, 1, 83–106.
  30. Dušek K: Network build-up and structure in curing of epoxy resins. Makromol Chem 1987, 7, 1, 37–53.
© Wroclaw Medical University