title: NH4HCO3gas-generating liposomal nanoparticle for photoacoustic imaging in breast cancer.
abstract: In this study, we have developed a biodegradable nanomaterial for photoacoustic imaging (PAI). Its biodegradation products can be fully eliminated from a living organism. It is a gas-generating nanoparticle of liposome-encapsulating ammonium bicarbonate (NH4HCO3) solution, which is safe, effective, inexpensive, and free of side effects. When lasers irradiate these nanoparticles, NH4HCO3decomposes to produce CO2, which can absorb much of the light energy under laser irradiation with a specific wavelength, and then expand under heat to generate a thermal acoustic wave. An acoustic detector can detect this wave and show it as a photoacoustic signal on a display screen. The intensity of the photoacoustic signal is enhanced corresponding to an increase in time, concentration, and temperature. During in vivo testing, nanoparticles were injected into tumor-bearing nude mice through the caudal vein, and photoacoustic signals were detected from the tumor, reaching a peak in 4 h, and then gradually disappearing. There was no damage to the skin or subcutaneous tissue from laser radiation. Our developed gas-generating nanomaterial, NH4HCO3nanomaterial, is feasible, effective, safe, and inexpensive. Therefore, it is a promising material to be used in clinical PAI.
authors.affiliation: Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Jizhu
authors.initials: J
authors.lastname: Xia
authors.affiliation: Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Feng
authors.affiliation: Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Xia
authors.affiliation: Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Lan
authors.initials: L
authors.lastname: Hao
authors.affiliation: Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D001639:Bicarbonates / Q000737:chemistry*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D045744:Cell Line, Tumor; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008081:Liposomes; D008325:Mammary Neoplasms, Experimental / Q000175:diagnosis / Q000473:pathology; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D061848:Optical Imaging; D061088:Photoacoustic Techniques / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D012996:Solutions; D013055:Spectrophotometry, Infrared; D040521:Subcutaneous Tissue / Q000473:pathology; D013696:Temperature; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D001639:Bicarbonates; D008081:Liposomes; D012996:Solutions; C027043:ammonium bicarbonate
keywords: CO2; NH4HCO3; Photoacoustic tomography; cancer; contrast agent