Two-dimensional cell sheet manipulation of heterotypically co-cultured lung cells utilizing temperature-responsive culture dishes results in long-term maintenance of differentiated epithelial cell functions.

Here we report two-dimensional cell sheet manipulation (2D CSM) of heterotypically co-cultured lung cell sheets and the maintenance of differentiated phenotypes of lung epithelial cells over prolonged periods of up to 70 days. This was facilitated by poly(N-isopropylacrylamide) (PIPAAm)-grafted tissue culture dishes. PIPAAm-grafted dishes are responsive to temperature changes and offer a unique surface on which cells adhere and multiply like on ordinary tissue culture dishes under the permissive temperature of 37 degrees C, but on lowering of temperature resulting in changes in hydration of the polymer the cells spontaneously detach from the surface without use of enzymes like trypsin which is the common procedure.

Thermally responsive polymer-grafted surfaces facilitate patterned cell seeding and co-culture.

Tissue engineering constructs that effectively duplicate natural tissue function must also maintain tissue architectural and organization features, particularly the integration of multiple cell types preserving distinct, integrated phenotypes. Cell-cell communication and biochemical cross-talk have been shown to be essential for the maintenance of differentiated cell functions in tissues and organs. Current limitations of cell-culture hinder progress in understanding the features and dynamics of heterotypic cell communication pathways critical to developing more sophisticated or effective tissue-engineered devices.

Pulsatile drug release control using hydrogels.

Current research in the field of drug delivery devices, by which pulsed and/or pulsatile release is achieved, has been intensified. In this article several types of drug delivery systems using hydrogels are discussed that showed pulsed and/or pulsatile drug delivery characteristics. As is frequently found in the living body, many vital functions are regulated by pulsed or transient release of bioactive substances at a specific site and time.

Adhesion behavior of monocytes, macrophages, and foreign body giant cells on poly (N-isopropylacrylamide) temperature-responsive surfaces.

Monocyte and macrophage adhesion and foreign body giant cell (FBGC) formation has been observed on surfaces with a wide range of properties. In this study we have utilized novel, temperature-responsive surfaces (TRS) with dynamic surface properties to investigate inflammatory cell adhesion behavior. With temperature changes, grafted chains of poly-N-isopropylacrylamide pass through their lower critical solution temperature (LCST) and can either extend (hydrate), creating a hydrophilic surface at 20 degrees C, or contract (dehydrate), creating a hydrophobic surface at 37 degrees C.