Intravascular contrast agents in diagnostic applications： Use of red blood cells to improve the lifespan and efficacy of blood pool contrast agents

In medicine, discrimination between pathologies and normal areas is of great importance, and in most cases, such discrimination is made possible by novel imaging technologies. Numerous modalities have been developed to visualize tissue vascularization in cardiovascular diseases or during angiogenic and vasculogenic processes. Here, we report the recent advances in vasculature imaging, providing an overview of the current non-invasive approaches in biomedical diagnostics and potential future strategies for prognostic assessment of vessel diseases, such as aneurysms and coronary artery occlusion leading to myocardial infarction. There are several contrast agents （CAs） available to improve the visibility of specific tissues at the early stage of diseases, allowing for rapid treatment. However, CAs are also hampered by numerous limitations, including rapid diffusion from blood vessels into the interstitial space, toxicity, and low sensitivity. Extravasation from blood vessels leads to a rapid loss of the image. If the contrast medium can fully be confined to the vascular space, high-resolution structural and functional vascular imaging could be obtained. Many scientists have contributed new materials and/or new carrier systems. For example, the use of red blood cells （RBCs） as CA-delivery systems appears to provide a scalable alternative to current procedures that allows adequate vascular imaging. Recognition and removal of CAs from the circulation can be prevented and/or delayed by using RBCs as biomimetic CA-carriers, and this technology should be clinically validated.

Second-harmonic generation as a DNA malignancy indicator of prostate glandular epithelial cells

This paper first demonstrates second-harmonic generation （SHG） in the intact cell nucleus, which acts as an optical indicator of DNA malignancy in prostate glandular epithelial cells. Within a scanning region of 2.7 μm×2.7μm in cell nuclei, SHG signals produced from benign prostatic hyperplasia （BPH） and prostate carcinoma （PC） tissues （mouse model C57BL/6） have been investigated. Statistical analyses （t test） of a total of 405 measurements （204 nuclei from BPH and 201 nuclei from PC） show that SHG signals from BPH and PC have a distinct difference （p 〈 0.05）, suggesting a potential optical method of revealing very early malignancy in prostate glandular epithelial cells based upon induced biochemical and/or biophysical modifications in DNA.

Triboelectric nanogenerators for clinical diagnosis and therapy:A report of recent progress

Triboelectric nanogenerators(TENGs)are considered as an ideal platform for power harvesting for living organisms,thanks to their unique characteristics like flexibility,conversion efficient,and manufacturing cost.Recent advances in TENGs have brought innovative solutions for clinical healthcare.Particularly,TENGs offer novel solutions of continues power supply for wearable and implantable medical devices with lightweight,thinness,good biocompatibility,and excellent soft tissue conformability.In this review,we discuss(1)The working principle and representative structure of TENGs,(2)the material selection of TENGs,(3)the recent progression of application of TENG in the medical field of cardiovascular system,nervous system,respiratory system,microbial inactivation,antibiofouling,disinfection,and tissue repair,(4)challenges and future perspectives of TENG-based medical devices.The emerging TENGs and their applications in medicine cannot simply be seen as an alternative to conventional power supplies,it provides a revolutionary solution for wearable and implantable medical devices,and they will surely change the paradigm of disease diagnosis and treatment in the future.