Biomedical subjects

Yukiko Tsuda

Publications and source records attributed to Yukiko Tsuda.

3 recordsLinked to original sources

PubMed2006

Heterotypic cell interactions on a dually patterned surface.

It is worth investigating heterotypic cell-cell interactions by mimicking their in vivo structures and environment. In the present study, physiological cellular response and behavior of hepatocytes and endothelial cells were investigated by controlling their contact periphery in a new co-culture system. Rat primary hepatocytes and bovine endothelial cells were co-cultured on a dually patterned surface. Hepatic physiological functions such as albumin secretion and ammonium metabolism were enhanced by increasing heterotypic cell-cell interactions in a patterned co-culture. Furthermore, enhanced hepatic functions through heterotypic interactions are effective within a limited area apart from endothelial cells as evidenced by immunofluorescence staining of hepatic intracellular albumin, indicating that heterotypic interactions act in a paracrine manner. Thus, heterotypic cell communications that play indispensable roles in increasing hepatic physiological functions should be obtained with an increasing periphery of two-cell domains. These findings are important for the reconstruction of complex tissues such as liver and pancreas.

Animals↗

PubMed2005

The use of patterned dual thermoresponsive surfaces for the collective recovery as co-cultured cell sheets.

Heterotypic cell interactions are critical to achieve and maintain specific functions in many tissues and organs. We have focused on patterned structure surfaces to enable co-culture of heterotypic cells and recovery of patterned co-cultured cell sheets for applications in tissue engineering. Thermoresponsive polymers exhibiting different transition temperatures in water comprise both poly(N-isopropylacrylamide) (PIPAAm) and n-butyl methacrylate (BMA) co-grafted as side chains to PIPAAm main chains. These copolymers were surface-grafted in patterns to obtain patterned dual thermoresponsive cell culture surfaces using electron beam polymerisation method and porous metal masks. On patterned surfaces, site-selective adhesion on and growth of rat primary hepatocytes (HCs) and bovine carotid endothelial cells (ECs) allowed patterned co-culture, exploiting hydrophobic/hydrophilic surface chemistry regulated by culture temperature as the sole variable. At 27 degrees C, seeded HCs adhered exclusively onto hydrophobic, dehydrated P(IPAAm-BMA) co-grafted domains (1-mm laser dot), but not onto neighbouring hydrated PIPAAm domains. Sequentially seeded ECs then adhered exclusively to hydrophobised PIPAAm domains upon increasing culture temperature to 37 degrees C, achieving patterned co-cultures. Reducing culture temperature to 20 degrees C promoted hydration of both polymer-grafted domains, permitting release of the co-cultured, patterned cell monolayers as continuous cell sheets with heterotypic cell interactions. Recovered co-cultured cell sheets can be manipulated, moved and sandwiched with other structures, providing new useful constructs both for basic cell biology research and preparation of tissue-mimicking multi-layer materials through overlaying co-cultured cell sheets.

Acrylic Resins↗

PubMed2004

Control of cell adhesion and detachment using temperature and thermoresponsive copolymer grafted culture surfaces.

The hydrophobic monomer, n-butyl methacrylate (BMA) has been incorporated into thermoresponsive poly(N-isopropylacrylamide) (PIPAAm) to lower PIPAAm phase transition temperatures necessary for systematically regulating cell adhesion on and detachment from culture dishes at controlled temperatures. Poly(IPAAm-co-BMA)-grafted dishes were prepared by electron beam irradiation methods, systematically changing BMA content in the feed. Copolymer-grafted surfaces decreased grafted polymer transition temperatures with increasing BMA content as shown by water wettabilities compared to homopolymer PIPAAm-grafted surfaces. Bovine endothelial cells readily adhered and proliferated on copolymer-grafted surfaces above collapse temperature at 37 degrees C, finally reaching confluence. Cell sheet detachment behavior from copolymer-grafted surfaces depended on the culture temperature and BMA content. In conclusion, cell attachment/detachment can be controlled to an arbitrary temperature by varying the content of hydrophobic monomer incorporated into PIPAAm grafted to culture surfaces.

Animals↗