Microvasculatures may become damaged by a variety of acute and chronic diseases. In many cases, microvessel function is irreversibly compromised, leading to the dysfunction and even death of surrounding tissues. Currently, there are few therapies that directly address the treatment of microvascular insufficiency. Responding to this need, researchers are developing methods to fabricate in vitro blood vessels. Typical strategies include; cellular sodding within polymers and/or biopolymers, the formation of cylindrical cellular monolayers around polymer mandrels, and the modification of biocompatible surfaces for cellular adhesion. Using currently available techniques, simple, individual vessel conduits have been engineered with internal diameters down to 150μm. However, no evidence has been provided illustrating the formation of patent, interconnected microvessel networks without the aid of a host circulatory system.

In response to this challenge, it is hypothesized that a novel flow-based experimental system will support the in vitro development of three-dimensional microvascular tissues. Addressing this hypothesis, the presented work focused on three specific aims: Specific Aim 1. Pattern planar in vitro three-dimensional microvasculatures. Specific Aim 2. Engineer a Dynamic In vitro Perfusion Chamber (DIP Chamber) for microvascular investigation. Specific Aim 3. In vitro perfusion of microvessel fragments within the DIP Chamber. Through the supporting experiments, directed endothelial sprouting from parent isolated microvessel fragments was achieved. In addition, patent in vitro microvessel networks were successfully developed. The presented experiments are the first to achieve these experimental results. In addition, the described experimental model will provide a unique method for future investigations of microcirculatory phenomena. Since no exogenous growth factors or cell signals were introduced into the constructs, it is believed that this system presents a physiological platform for future investigations into angiogenesis, angioadaptation, and network remodeling. Moreover, this model may offer a useful platform for vascular therapeutic testing and a foundation for future tissue engineering applications.