Photoacoustic imaging and photoacoustic spectrum analysis in mouse models of cutaneous squamous cell carcinoma / 中华皮肤科杂志

Objective To establish a photoacoustic detection system and data processing methods for skin tumors,and to explore photoacoustic imaging and photoacoustic spectrum in mouse models of cutaneous squamous cell carcinoma (CSCC).Methods A total of 60 healthy specific pathogen-free (SPF) female BALB/C nude mice aged 6-8 weeks were randomly and equally divided into 2 groups to be inoculated with a murine CSCC cell line XL50 and a human CSCC cell line A431 respectively on the right back near the upper limbs,and mouse models of murine CSCC (n =20) and human CSCC (n =20) were successfully established.The 850-nm photoacoustic detection system was applied in the above 2 kinds of mouse models,and photoacoustic imaging and photoacoustic spectrum data were collected.The fitted slope of acoustic power spectrum curves was compared between squamous cell carcinoma tissues and normal skin on the left back of the mouse model.After the photoacoustic detection,tumor tissues and normal skin at the opposite side were excised from the 2 kinds of mouse models,and subjected to histopathological examination.The fitted slope of different tissues was compared by using t test.Results Photoacoustic imaging showed higher photoacoustic signals of hemoglobin in squamous cell carcinoma tissues compared with the normal skin tissues.In the model of murine CSCC,the fitted slope of acoustic power spectrum curve was significantly lower in the tumor tissues (-1.827 ± 0.153 1) than in the normal skin tissues (-1.059 ± 0.117 8,t =3.973,P ＜ 0.001).In the model of human CSCC,the fitted slope of acoustic power spectrum curve was also significantly lower in the tumor tissues (-1.537 ± 0.125 5) than in the normal skin tissues (-0.960 ± 0.259 7,t =2.166,P =0.043).Histopathological examination showed that the number of vessels increased in the tumor tissues compared with the normal skin tissues.Conclusion CSCC tissues are different from normal skin tissues in photoacoustic imaging signals and the fitted slope of acoustic power spectrum,which may lay a foundation for non-invasive photoacoustic diagnosis of CSCC.

Progression in photoacoustic imaging for cancer diagnosis and therapy / 中华核医学与分子影像杂志

Photoacoustic imaging (PAI) is an emerging new biomedical imaging technique integrated with the high spatial resolution of ultrasonic imaging and high contrast of optical imaging for real-time molecular imaging.PAI is well-suited for in vivo cellular/molecular signatures imaging in cancer diagnosis, therapy management and treatment response, with a promising potential in clinical and translational medicine.This review summarizes the current state of PAI application research on cancer theranostics, and gives insights on future translational medicine research.

Clinical photoacoustic imaging of cancer

Photoacoustic imaging is a hybrid technique that shines laser light on tissue and measures optically induced ultrasound signal. There is growing interest in the clinical community over this new technique and its possible clinical applications. One of the most prominent features of photoacoustic imaging is its ability to characterize tissue, leveraging differences in the optical absorption of underlying tissue components such as hemoglobin, lipids, melanin, collagen and water among many others. In this review, the state-of-the-art photoacoustic imaging techniques and some of the key outcomes pertaining to different cancer applications in the clinic are presented.

Targeted multifunctional nanoparticles probe mediated photoacoustic imaging and treatment study of breast carcinoma in vitro / 中华超声影像学杂志

Objective To investigate the ability of targeting in vitro breast carcinoma and photoacoustic-mediate apoptosis of breast carcinoma of the nanoparticle probe loaded with Fe3O4 and observe its consequence of photoacoustic imaging in vitro.Methods The polymeric multifunctional nanoparticles probe that was loaded with Fe3O4 and connected with Herceptin targeting breast carcinoma was prepared in the use of double emulsion method and carbodiimide method.General physical property,the condition of Herceptin connected with nanoparticles and the ability of targeting of the probe were tested.The different concentration of nanoparticles was imaged by photoacoustic.The inhibiting effect of targeting nanoparticles on breast carcinoma cells was evaluated in vitro.Results The targeting polymeric multifunctional nanoparticles probes loaded with Fe3O,were prepared successfully with average particle diameter of (235.4± 53.75)nm and Zeta potential (-13.4 ± 4.7)mV.Fe3O4 particles dispersed on the shell of the probes.Antibody Hereeptin was successfully connected with the surface of the nanoprobes.There were massive targeting nanoprobes surround the breast carcinoma cell strains SKBR3 in the targeting group in vitro.The photoascoustic signal of the nanoprobes enhanced with the increase of Fe3O4 concentration in photoacoustic experiment in vitro.The apoptotic rate of breast carcinoma increased after the laser irradiation in the cell inhibition experiment in vitro.That proved the obvious inhibition of breast carcinoma cells was caused by photothermal effect of the prepared nanoprobes.Conclusions The prepared polymeric multifunctional nanoparticles probe that was loaded with Fe3O4 and connected with Herceptin targeting breast carcinoma can be used as a photoacoustic contrast agent,which can inhibit the proliferation of breast carcinoma by targeting photoacoustic therapy.

Production of a dual model probe for photoacoustic imaging and fluorescence imaging targeting integrinαvβ6 / 中华超声影像学杂志

Objective To develop a probe for photoacoustic imaging and fluorescence imaging targeting integrin αvβ6 . Methods The probe was separated by RP‐HPLC .Molecular weight and the maximum absorption wavelength of the probe were detected by mass spectrum instrument and optical spectrum instrument . Various concentrations of the probe were detected by photoacoustic imaging and fluorescence imaging . The stability of the probe was evaluated when exposed under laser . Targeting of the probe on integrinαvβ6 was evaluated in cell uptake assay with integrinαvβ6 positive and negative cells . The minimum number of cells that could be detected by photoacoustic imaging and fluorescence imaging was also evaluated . Results The probe ICG‐peptide was separated from reaction mixture by RP‐HPLC .The probe had a retention time of 21 .4 minutes and m/z of 4 727 . The labeling ratio of the probe was 1∶1 . The maximum absorption wavelength of the probe was 790 nm . The photoacoustic signal was linearly dependent on the concentration of the probe . The fluorescence signal was linearly dependent on the concentration of the probe when the concentration was smaller than 1 .5 × 10 -5 mol/L . The lowest concentration of the probe that could be detected above the background by photoacoustic imaging and fluorescence imaging was 0 .09 × 10-5 mol/L and 0 .05 × 10-5 mol/L ,respectively . No obvious decrease of the photoacoustic signal was observed after the probe was scanned 20 times ( each time lasted for 1 min) by laser . There existed differences ( P <0 .001) in cell uptake of the probe with various concentrations and reaction time between A431 cells (αvβ6 positive) and 293T cells (αvβ6 negative) . Cell uptake was inhibited by the addition of 5μmol/L unlabeled peptide in A431 cells ( P = 0 .001 ) . The lowest number of the labeled A431 cells detected by photoacoustic imaging and fluorescence imaging was 0 .4 × 106 and 0 .05 × 106 ,respectively . Conclusions The dual functional photoacoustic and fluorescence probe targeting integrin αvβ6 was successfully developed . The targeting and sensitivity of the probe makes it potentially useful in early detection of αvβ6 positive tumors .