Model hydrogel colloids as mimics of mycoplasma

Model hydrogel colloids as mimics of mycoplasma


Biological contaminants such as microbes and viruses are the most important challenges in the (bio)pharmaceutical industry. For sterilization of biological fluid product media, polymeric membranes are commonly used due to low cost, high energy efficiency and mild thermal conditions. The separation of infectious and highly deformable colloidal microorganisms like mycoplasma is influenced by a variety of parameters in a complex way which is not clarified yet [1]. Furthermore, some mycoplasma species can even penetrate state of the art sterile filtration membranes [1]. Consequently, there is a need for development of membranes allowing an efficient separation of such infectious species. However, cultivation and detection of mycoplasma is rather difficult. Colloids mimicking critical properties of mycoplasma and enabling easy analysis may therefore help to gain a fundamental understanding of processes and parameters influencing their removal by membrane filtration.

Since the separation performance is not exclusively affected by size exclusion, the MykoRet project addresses the detailed characterization of the filtration process and the retention mechanism for mycoplasma and mycoplasma analogous deformable colloidal particles with respect to different variables affecting the separation efficiency such as i) membrane properties; ii) filtration conditions; iii) matrix interactions.

The fabrication of colloids mimicking mycoplasma and their properties such as size, shape, deformability and surface charge is performed by syntheses of homogenously cross-linked poly(acrylamide) micro- and nanogels with narrow particle size distributions in the range of 50 – 500 nm. This is achieved using inverse miniemulsion polymerization of acrylamide and N,N'-methylenebisacrylamide as cross-linker [2]. Terpolymerization with different comonomers allows tailoring of the surface charge. For detection and quantitative analysis two ways of labelling are explored, through i) fluorescent dyes or ii) reactive loading with noble metal nanoparticles.


  1. M. Folmsbee, M. Moussourakis, Bioprocess Int. 2012, 10, 60
  2. K. Landfester, A. Musyanovych, in (Eds. A. Pich, W. Richtering) Chemical Design of Responsive Microgels, Berlin, Springer, 2010, 234, 39


Funding: This work is supported by the Federal Ministry of Education and Research (grant # 13N13111 "Mykoret").

Prof. Dr. Mathias Ulbricht