Abstract: Developing a Calcium Alginate Droplet Generator for the Formation of Uniformly Sized Multicellular Tumor Spheroids (Science, Technology, and Diversity for a Healthy World)

Thursday, October 11, 2012: 6:35 PM

617 (WSCC)

Jacqueline De Lora, BS/BA , Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM

Travis Woods, BS , Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM

Alice Martinic , Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM

Blake Bluestein , Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM

Heather Canavan, PhD , Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM

James Freyer, PhD , Department of Chemical and Nuclear Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM

The complexity of cellular interactions within tissues is not physiologically relevant in conventional 2D monolayer cell culture. Cells cultured in 2D lack cell-cell and cell-matrix signaling information and microenvironmental gradients normally experienced by cells within a 3D tissue or tumor. Multicellular aggregates, or spheroids, are an in vitro model for the investigation of 3D, tissue-like microenvironments. New spheroid formation technologies are needed to replace the current time consuming protocols and lack of uniformly sized populations. We have designed a protocol for cell encapsulation and formation of monodispersed spheroids using calcium alginate hydrogel chemistry and a droplet generating flow cell from a conventional flow cytometer. We first measured the kinematic viscosity of the sodium alginate pre-gel solution using an Ostwald viscometer. These data were used to quantitatively model the pressure required to generate laminar flow of the highly viscous pre-gel through the flow cell. To produce uniform spherical aggregates, sodium alginate pre-gel containing cells is passed through the device. Vibration of the 100 μm flow nozzle causes a uniform displacement of the flow stream. Uniform cell encapsulated microspheres are generated and crosslinked by dropping them into a calcium- containing solution. This forms monodispersed calcium alginate microspheres encapsulating a precise number of cells. We are actively optimizing the platform to produce cell-encapsulated microspheres of different sizes and cellular compositions. In the future we will determine (1) biocompatibility of the microspheres, (2) diffusion coefficient of the microspheres using fluorescence recovery after photobleaching, and (3) proficiency of culturing uniformly sized spheroids.

Room 617 Developing a Calcium Alginate Droplet Generator for the Formation of Uniformly Sized Multicellular Tumor Spheroids