Cardiovascular diseases are increasingly becoming the main cause of death all over the world, leading to an increase in the economical and social burden. Vascular tissue engineering (VTE) is paving its routes toward challenging applications, focused mainly on substitutions of small-diameter blood vessels (\6 mm). Native collagen, a natural biological material which possesses extraordinary properties in terms of biocompatibility, has been extensively investigated as a scaffold for VTE. However, collagen is mainly extracted from collagen-rich native natural tissues by different harsh chemical and physical treatments, resulting in a solution susceptible to be processed for the fabrication of supports. These treatments imply the destruction of the native organization of the collagen microstructure, thus resulting in a collagen-based support less resistant in terms of mechanical properties than the native one. Therefore, different approaches have been investigated to increase these mechanical properties. Although UV irradiation present a strong potential for efficient crosslinking collagen macromolecules, the undesirable effects of UV on cell activity still remain the main challenge to be overpassed. The aim of this study was to investigate the potential of UV radiation and glycation for the crosslinking of collagen gels, with particular concern to the cells and capacity of the cells to remodel the collagen structure.

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To date, design guidance for hydraulic occulators has been limited, with several articles focusing on the design horizontally-baed hydraulic occulators. In this paper, a design algorithm for vertically-baed hydraulic occulators is introduced based on physical principles governing baed hydraulic occulator performance. Verticallybaed hydraulic occulators are more compact than their horizontally-baed counterparts for design ow rates less than about 200 L/s (5 MGD). Well designed hydraulic occulators have more uniform velocity gradients than conventional mechanical occulators, approach plug-ow behavior which has faster occulation kinetics and less short-circuiting, and are low cost to operate and maintain. The above characteristics make vertically-baed occulators an ideal choice for rural and resource-limited settings. Design algorithms based on theoretical and practical considerations are developed, after which two illustrative design examples are given. Afterwards, a discussion of the range of applicability for vertically-baed and horizontally-baed hydraulic occulators is presented. This vertically-baed hydraulic occulator design approach has been proven in Central America, where it has been used to design seventeen occulators that are currently in use and have demonstrated dependable performance and low cost operation and maintenance.