4. Conclusion
In this study, we report an advanced and biomimetic microfluidic platform making use of an enzymatically crosslinked eSF hydrogel, by combining photolithography and soft lithography. Functional devices were obtained in amorphous conformation with unique characteristics, such as good malleability, high transparency and flexibility. The silk fibroin concentration that presented the best characteristics was 14 wt%, proving that it retains the intricate serpentine features with high level of fidelity. Next, the platform showed a good ability to mimic characteristic features of the native tumor microenvironment, displaying a friendly microenvironment for cells functions as demonstrated by the measured cell viability and metabolic activity. The perfusion of gemcitabine affected cell viability and demonstrated the utility of the developed cell-laden enzymatic-crosslinked silk protein fibroin microfluidic chip to be utilized as a drug screening platform. Importantly, the improvement of soft microfluidics such as the one developed herein present some important features over the hard microfluidics (PDMS), e.g. physiological relevance, functional space, flexibility, ECM interaction analysis, optical properties and easy manipulation. Overall, the developed soft cell-laden enzymatic-crosslinked silk fibroin hydrogel based microfluidic device may be used in tissue engineering applications, organ or tissue/tumor models, drug discovery/screening, a tissue implant, tissue regeneration or, more interestingly, as implantable and biocompatible microdevices.