An investigation into cellular attachment and contraction in collagen-GAG scaffolds with characterized pore sizes

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004.Vita.Includes bibliographical references (p. 99-104).Scaffolds fabricated from natural and man-made polymers have historically been used in partial- and full-thickness dermal wound beds to inhibit contraction and promote natural healing of tissue. By encouraging fibroblast migration and proliferation in the scaffolds, it is possible to reduce scar tissue formation and regenerate functioning dermis. A series of experiments were performed to determine the effects of average pore size and available surface area in a lyophilized Collagen-GAG scaffold on the infiltration and attachment of dermal fibroblasts. An updated design of the Cell Force Monitor (CFM) was used to quantify bulk cellular contractile behavior in seeded scaffolds. The effect of scaffold geometry on fibroblast contractile behavior was also investigated with the CFM. Results show that cellular seeding methods employed led to cellular agglomeration on the surfaces of the scaffolds, negating any possible correlation between internal available surface area and cellular attachment. It was also discovered that cell culture passaging techniques have more of an influence on cellular contractile behavior than scaffold pore size, given the seeding techniques employed in this study. No correlation was found between contractile behavior and scaffold geometry in the CFM.by Andrew Michael Albers.S.M

Experimental Analysis of Droplet Generation in Presence of Newtonian and non-Newtonian Flows within Microjunctions

Microdroplets have attracted increasing interest among researchers due to the wide spread of promising technological applications such as biological analysis, cancer diagnosis, drug discovery and chemical reactions. With respect to traditional emulsion methods which are usually able to produce droplets with a broad size variation (polydispersed emulsions), microfluidic devices have been developed to produce monodispersed microdroplets with a controllable size. The diameter and size variation of droplets are controlled by a series of parameters, including the geometries and dimensions of the microfluidic devices, properties of the liquids, flow rates and surfactant concentrations. In this Ph.D. thesis, droplet formation has been analyzed experimentally, thanks to a series of specific tests on simple microfluidic devices devoted to droplet generation based on the use of T-junctions or micro cross-junctions. The experimental work has been focused on the analysis of the control of droplet regime which can be activated in a microfluidic droplet generator in presence of Newtonian and non-Newtonian dispersed phases, with or without the addition of surfactants. The mechanism of the droplet formation has been studied by following the evolution of the interface between the immiscible liquids at the microjunction thanks to the post processing of images acquired by using a speed camera connected to an inverted microscope. In order to study the behavior of non-Newtonian shear thinning liquids during droplet formation, Xanthan gum aqueous solutions have been used because their rheological properties are very similar to those of blood. The effect on the droplet regimes of the main controlling parameters, such as the flow rates of the immiscible liquids introduced in the microfluidic device, fluid viscosity and interfacial tension has been studied with the aim to individuate the range of these controlling parameters for which the microfluidic device is able to produce monodispersed droplets with an assigned volume and frequency

Modern meat: the next generation of meat from cells

Modern Meat is the first textbook on cultivated meat, with contributions from over 100 experts within the cultivated meat community. The Sections of Modern Meat comprise 5 broad categories of cultivated meat: Context, Impact, Science, Society, and World. The 19 chapters of Modern Meat, spread across these 5 sections, provide detailed entries on cultivated meat. They extensively tour a range of topics including the impact of cultivated meat on humans and animals, the bioprocess of cultivated meat production, how cultivated meat may become a food option in Space and on Mars, and how cultivated meat may impact the economy, culture, and tradition of Asia