Santiago Mille Fragoso

All Publications

• Photoacoustic imaging of 3D-printed vascular networks. Biofabrication Ma, C., Li, W., Li, D., Chen, M., Wang, M., Jiang, L., Mille, L. S., Garciamendez, C. E., Zhao, Z., Zhou, Q., Zhang, Y. S., Yao, J. 1800; 14 (2)

  Abstract

  Thrombosis in the circulation system can lead to major myocardial infarction and cardiovascular deaths. Understanding thrombosis formation is necessary for developing safe and effective treatments. In this work, using digital light processing (DLP)-based 3D printing, we fabricated sophisticatedin vitromodels of blood vessels with internal microchannels that can be used for thrombosis studies. In this regard, photoacoustic microscopy (PAM) offers a unique advantage for label-free visualization of the 3D-printed vessel models, with large penetration depth and functional sensitivity. We compared the imaging performances of two PAM implementations: optical-resolution PAM and acoustic-resolution PAM, and investigated 3D-printed vessel structures with different patterns of microchannels. Our results show that PAM can provide clear microchannel structures at depths up to 3.6 mm. We further quantified the blood oxygenation in the 3D-printed vascular models, showing that thrombi had lower oxygenation than the normal blood. We expect that PAM can find broad applications in 3D printing and bioprinting forin vitrostudies of various vascular and other diseases.

  View details for DOI 10.1088/1758-5090/ac49d5

  View details for PubMedID 35008080

• Microfluidic integration of regeneratable electrochemical affinity-based biosensors for continual monitoring of organ-on-a-chip devices NATURE PROTOCOLS Aleman, J., Kilic, T., Mille, L. S., Shin, S., Zhang, Y. 2021; 16 (5): 2564-2593

  Abstract

  Organs-on-chips have emerged as viable platforms for drug screening and personalized medicine. While a wide variety of human organ-on-a-chip models have been developed, rarely have there been reports on the inclusion of sensors, which are critical in continually measuring the microenvironmental parameters and the dynamic responses of the microtissues to pharmaceutical compounds over extended periods of time. In addition, automation capacity is strongly desired for chronological monitoring. To overcome this major hurdle, in this protocol we detail the fabrication of electrochemical affinity-based biosensors and their integration with microfluidic chips to achieve in-line microelectrode functionalization, biomarker detection and sensor regeneration, allowing continual, in situ and noninvasive quantification of soluble biomarkers on organ-on-a-chip platforms. This platform is almost universal and can be applied to in-line detection of a majority of biomarkers, can be connected with existing organ-on-a-chip devices and can be multiplexed for simultaneous measurement of multiple biomarkers. Specifically, this protocol begins with fabrication of the electrochemically competent microelectrodes and the associated microfluidic devices (~3 d). The integration of electrochemical biosensors with the chips and their further combination with the rest of the platform takes ~3 h. The functionalization and regeneration of the microelectrodes are subsequently described, which require ~7 h in total. One cycle of sampling and detection of up to three biomarkers accounts for ~1 h.

  View details for DOI 10.1038/s41596-021-00511-7

  View details for Web of Science ID 000645191100006

  View details for PubMedID 33911259