Dip TIPS as a facile and versatile method for fabrication of polymer foams with controlled shape, size and pore architecture for bioengineering applications

PLoS One. 2014 Oct 2;9(9):e108792. doi: 10.1371/journal.pone.0108792. eCollection 2014.

Abstract

The porous polymer foams act as a template for neotissuegenesis in tissue engineering, and, as a reservoir for cell transplants such as pancreatic islets while simultaneously providing a functional interface with the host body. The fabrication of foams with the controlled shape, size and pore structure is of prime importance in various bioengineering applications. To this end, here we demonstrate a thermally induced phase separation (TIPS) based facile process for the fabrication of polymer foams with a controlled architecture. The setup comprises of a metallic template bar (T), a metallic conducting block (C) and a non-metallic reservoir tube (R), connected in sequence T-C-R. The process hereinafter termed as Dip TIPS, involves the dipping of the T-bar into a polymer solution, followed by filling of the R-tube with a freezing mixture to induce the phase separation of a polymer solution in the immediate vicinity of T-bar; Subsequent free-drying or freeze-extraction steps produced the polymer foams. An easy exchange of the T-bar of a spherical or rectangular shape allowed the fabrication of tubular, open- capsular and flat-sheet shaped foams. A mere change in the quenching time produced the foams with a thickness ranging from hundreds of microns to several millimeters. And, the pore size was conveniently controlled by varying either the polymer concentration or the quenching temperature. Subsequent in vivo studies in brown Norway rats for 4-weeks demonstrated the guided cell infiltration and homogenous cell distribution through the polymer matrix, without any fibrous capsule and necrotic core. In conclusion, the results show the "Dip TIPS" as a facile and adaptable process for the fabrication of anisotropic channeled porous polymer foams of various shapes and sizes for potential applications in tissue engineering, cell transplantation and other related fields.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bioengineering / methods*
  • Calorimetry, Differential Scanning
  • Male
  • Mercury / analysis
  • Microscopy, Electron, Scanning
  • Molecular Weight
  • Phase Transition*
  • Polymers / chemistry*
  • Porosity
  • Rats, Inbred BN
  • Surface Properties
  • Temperature*
  • Time Factors
  • Tissue Scaffolds / chemistry

Substances

  • Polymers
  • Mercury

Grants and funding

The study was funded by the Ministry of Education, Youth and Sports, Czech Republic (grant number EE2.3.30.0029, awarded to IMC, Prague), by the Ministry of Health, Czech Republic (grant number 00023001, awarded to ICEM, Prague as an institutional support for the development of research organization), and by the European Regional Development Fund (Project BIOCEV: Biotechnology and Biomedicine Centre of the Academy of Science and Charles University, grant number CZ.1.05/1.1.00/02.0109, awarded to IMC, Prague). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.