Biomaterials-based microfluidics for engineered tissue constructs

The utility of microfluidics in biotechnology has dramatically increased in recent years as these systems have expanded to supplement efforts in lab-on-a-chip technology. The driving force for the widespread implementation of these systems for biological discovery is based on (1) miniaturization to increase sensitivity and reduce the scale of experimentation and (2) the ability to design high throughput systems. These two advantages have also motivated the integration of biomaterials with microfluidic structures and cell culture techniques. Micron scale systems enable precise control over cellular microenvironment while high throughput strategies are able to rapidly screen complex interactions such as cell-biomaterial responses. This review presents recent progress in the integration of biomaterials microfabrication and microfluidics-based cell culture systems towards tissue development. Materials considerations are of great importance in order to develop microfluidic biomaterials that are mechanically robust, compatible with established fabrication techniques, and able to accommodate the integration of viable cell populations. The use of biopolymers for these systems requires materials-specific microfabrication techniques for applications in microfluidic biomaterials. Pertinent examples that integrate aspects of biomaterials, microfabrication techniques, and cell culture for in vitro tissue morphogenesis are also discussed. These include systems designed to study basic mechanisms of tissue development, potential clinically relevant tissue engineered constructs, and in vitro model tissue systems for drug discovery and safety evaluation. The confluence of biomaterials-based microfluidics and controlled cellular integration portends the realization of far-reaching applications that span the spectrum between basic science and technologies for advancing human health.