The SlideReactor-A Simple Hollow Fiber Based Bioreactor Suitable for Light Microscopy

Membrane bioreactors enhance microenvironmental conditioning and tissue development

In membrane bioreactors the cells are isolated from the bulk medium through a semipermeable membrane. This concept, which is analogous to how the circulatory system supplies solid tissues with nutrients, allows the maintenance of cells at much higher densities than is possible in traditional cultures. The membrane-based microbioreactor described herein is easy to operate, requiring only a pipette to load and harvest cells. A 10 microL culture volume was isolated from 1 mL of bulk medium through a semipermeable membrane having a molecular weight cutoff of 10 kDa. Here we describe the benefits regarding the retention of both cells and their secretions within this small culture volume using the following two model systems: hematopoietic stem cell expansion and mesenchymal stem cell-derived cartilage matrix accumulation.

Continuously Microscopically Observed and Process-Controlled Cell Culture Within the SlideReactor: Proof of a New Concept for Cell Characterization

Certain cell types, especially primary human cells, favor a well-defined culture environment offering continuous supply of nutrients and oxygen and waste product removal. Several bioreactors based on special matrices or hollow fibers have been developed that provide such conditions. However, characterization of matrix re-organization or growth of tissue within these systems is possible only after culture termination. Evaluation of the influence of certain medium additives or culture conditions (e.g., temperature, oxygenation) on cell viability, expansion, and differentiation within these systems remains a challenging task. The SlideReactor, a miniaturized hollow fiber-based bioreactor, was developed to enable the observation of cells during culture. An operation concept offering predefined conditions for various cell types has been designed. For proof of concept, primary human cells (hepatocytes, fibroblasts, keratinocytes) and cell lines (HepG2, HuH7, C3A, WiDr, SkHep1) were cultured and observed. A series of experiments (n=40) showed the feasibility of the set-up; determination of process parameters and continuous observation is possible. The SlideReactor may serve as a simple and cost-efficient tool for cell characterization and optimization of cell-culture conditions.