A biodegradable, flexible photonic patch for in vivo phototherapy

Therapeutic and diagnostic illumination on internal organs and tissues with high controllability and adaptability in terms of spectrum, area, depth, and intensity remains a major challenge. Here, we present a flexible, biodegradable photonic device iCarP featured with a micrometer scale air gap constructed between a refractive polyester patch and the embedded removable tapered optical fiber (TOF). ICarP combines the advantages of light diffraction by TOF, dual refractions on TOF/air and air/patch interfaces of the air gap, and reflection inside the patch to obtain a “bulb-like” illumination, guiding the light towards the target tissue. Large area, high intensity, wide spectrum, continuous/pulsatile, deeply penetrating illumination was achieved without puncturing the target tissues. ICarP supported phototherapies with different photosensitizers and achieved higher efficacy compared to optical fibers with clinically relevant optical fiber structures, attributed to the light scattering effect. The robust photonic device is compatible with thoracoscopy-based minimally invasive implantation and exhibited consistent performance on mechanically dynamic animal hearts in a demonstrative application of in situ photosynthesis for myocardial infarction treatment. The iCarP phototherapy improved survival of cardiac cells and preserved cardiac functions. These initial results showed that iCarP could be a safe, precise and widely applicable device suitable for internal organs/tissues illumination and associated therapy and diagnosis. Overall design: Examination of the transcriptomes of rat heart tissue samples with the following treatments: n=4 MI, n=4 iCarP+/Light+, and n=4 Sham.