A robotic arm with open-source reconstructive workflow for <i>in vivo</i> bioprinting of patient-specific scaffolds

<i>In vivo</i> bioprinting, fabricating tissue-engineered implants directly in a patient, was recently developed to overcome the logistical and clinical limitations of traditional bioprinting. <i>In vivo</i> printing reduces the time to treatment, allows for real-time reconstructive adjustments, minimizes transportation challenges, improves adhesion to remnant tissue and ensuing tissue integration, and utilizes the body as a bioreactor. Unfortunately, most <i>in vivo</i> printers are frame-based systems with limited working areas that are incompatible with the human body and lack portability. Robotic arms have recently been used to resolve these challenges, but developed systems suffered from complex deposition or cross-linking modalities and lacked bioink temperature control, drastically limiting the use of biologically favorable bioinks. Here, we created a portable and affordable robotic arm bioprinter with precise control over bioink temperature. The system maintained biomaterial ink temperatures from 6 to 60 ± 0.05 °C. We tested a bioprinting optimization strategy with different temperature-sensitive bioinks. In addition, we engineered a personalized <i>in vivo</i> printing strategy derived from <i>in situ</i> scanning and model reconstruction that utilizes freely available and open-source software. We further demonstrated the benefits of human-derived bioinks made of blood components. The system and the proposed human-derived bioinks pave the way toward the personalization of scaffold-based regenerative medicine.