Pulsed electric field as a potential new method for microbial inactivation in scaffold materials for tissue engineering: The effect on collagen as a scaffold

Abstract

Hybrid scaffolds for tissue engineering are becoming increasingly complex through incorporation of biologically active biomacromolecules. There is a need to develop a compatible sterilization method that is capable of killing microorganisms, without adversely affecting the labile scaffold biomaterials or biomacromolecular components. Pulsed electric field (PEF) treatment has been successful as a nonthermal microbial inactivation-pasteurization method within the food industry. We have previously demonstrated that PEF treatment inactivates E. coli seeded in collagen gels. Here, we show that PEF treatment does not affect the structural integrity of the collagen molecule or its adsorption to polystyrene and hydroxyapatite surfaces. Moreover, osteoblast cells cultured on PEF-treated collagen, which was coated onto two- and three-dimensional scaffolds, retained their normal morphology, growth rate, and functionality. PEF treatment, therefore, shows great potential to be used as a sterilization method for collagen-based biomaterials.

Poly(N-acryloyl ciprofloxacin-co-acrylic acid) grafted magnetite nanoparticles for microbial decontamination of collagen solution: have we conquered the problem of antimicrobial residues?

“…7,8 Stepwise filtration is capable of removing bacteria and fungi from collagen solution, but not guaranteed to eliminate all viruses or mycoplasmas. 7,8 Stepwise filtration is capable of removing bacteria and fungi from collagen solution, but not guaranteed to eliminate all viruses or mycoplasmas.…”

“…Currently, the most commonly employed techniques for microbial decontamination of collagen include filtration, gamma-irradiation, fumigation with ethylene oxide, and sterilization using chloroform. 7,8 Stepwise filtration is capable of removing bacteria and fungi from collagen solution, but not guaranteed to eliminate all viruses or mycoplasmas. More importantly, a substantial portion of collagen macromolecules will be lost by being retained on the filter.…”

Decontamination of collagen biomatrices with combined pulsed electric field and nisin treatment

“…The ability of collagen matrices to engraft and generate new collagen is critical for clinical performance. The initial findings of PEF or nisin treatment of collagen matrices have not demonstrated any adverse effect, nisin‐treated gels were able to support cell proliferation and PEF treatment has been shown not to cause adverse effects to the structure of the collagen molecule at field strengths as high as 60 kV/cm 1. Similarly osteoblasts cultured on PEF‐treated collagen, coated onto two‐ or three‐dimensional scaffolds, retained their normal morphology, growth rate, and functionality 1.…”

“…The initial findings of PEF or nisin treatment of collagen matrices have not demonstrated any adverse effect, nisin‐treated gels were able to support cell proliferation and PEF treatment has been shown not to cause adverse effects to the structure of the collagen molecule at field strengths as high as 60 kV/cm 1. Similarly osteoblasts cultured on PEF‐treated collagen, coated onto two‐ or three‐dimensional scaffolds, retained their normal morphology, growth rate, and functionality 1. Although no adverse effect to the structure of collagen was detected after PEF treatment future work should be conducted to confirm that the mechanical properties of these collagen matrices also remain unaltered after either the individual or combined treatment of nisin and PEF.…”

“…Pulsed electric field (PEF) treatment has been proposed as a potential method for the inactivation of microorganisms in collagen gel matrices for use in tissue engineering 1. In order to develop an artificial tissue, typically a highly porous, degradable biomatrix or scaffold is required and can be critical in the success of the tissue engineered product.…”