Optical coherence tomography (OCT) has been used to noninvasively monitor the blood glucose concentration (BGC) in healthy subjects with good accuracy and acceptable specificity. Based on this, the paper further considered the possibility of OCT in noninvasive monitoring BGC in diabetic patients. The OCT signal slope (OCTSS) changed with variation of BGC. The correlation coefficient R between BGC and OCTSS in diabetic patients was 0.91; while the correlation coefficient R in healthy volunteers was 0.78. Thus, a better linear dependence of OCTSS on BGC in diabetic patients was presented in the experiment. The results showed that the capability and accuracy of OCT in noninvasive monitoring BGC of diabetic patients, and the noninvasive monitoring BGC in diabetic patients may be better than the monitoring in the healthy subjects.

The objective is to investigate the effects of two different sized (60 and 100 nm) titanium dioxide (TiO2) nanoparticles (NPs) penetration and accumulation in in vitro human normal lung (NL) tissue, lung squamous cell carcinoma (LSCC) tissue, and 650-nm diode laser-pretreated tissue on their optical properties studied with optical coherence tomography monitoring and diffuse reflectance (DR) spectra measurement. As with TiO2 NPs penetrating into the tissues, the intensities of DR of the samples increase, and then the enhancements of DR and the attenuation coefficients of the tissues were quantitatively calculated. The results suggest that 650-nm diode laser pretreatment increased the amounts of TiO2 NPs penetration and accumulation in NL and LSCC tissues, and the tissue optical properties were significantly influenced by accumulation of TiO2 NPs.

The aims of this study were to monitor and contrast the diffusion of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles’ (NPs) penetration and accumulation in human normal endometrium (NE) tissues and uterine leiomyoma (UL) tissues combined with microneedles (MN) in vitro using optical coherence tomography (OCT) and diffuse reflectance (DR) spectral. Continuous OCT and DR spectra monitoring showed that, after application of ZnO or TiO2 NPs, the OCT signal intensities of NE and UL both increase with time, and the TiO2 NPs tend to produce a greater signal enhancement than ZnO NPs in the same type of tissue. And for the same type of NPs, they penetrate faster in NE tissue compared with UL tissue. In addition, the use of MN can significantly enhance the penetration of topically applied ZnO or TiO2 NPs in the tissue. The attenuation coefficients of NE tissue are about 5.01  ±  0.35 mm−1 for ZnO NPs treatment at 195 min and 4.62  ±  0.29 mm−1 for ZnO NPs/MN at 179 min, 4.73  ±  0.30 mm−1 for TiO2 NPs at 183 min, 4.05  ±  0.25 mm−1 for TiO2 NPs/MN at 147 min when the penetration process reached the stable state. And the attenuation coefficients of UL tissue are about 5.0  ±  0.34 mm−1 for ZnO NP treatment at 191 min and 4.20  ±  0.26 mm−1 for ZnO NPs/MN at 169 min, 4.33  ±  0.27 mm−1 for TiO2 NPs at 176 min, 3.53  ±  0.20 mm−1 for TiO2 NPs/MN at 141 min when the penetration process reached the stable state. This suggests that TiO2 NPs penetrate faster and reach the maximum amount of penetration earlier than ZnO NPs with the same condition. The results of attenuation coefficients and reflectance intensity of NE and UL tissue suggests that the accumulation of the TiO2 or ZnO NPs in both NE and UL tissue greatly influenced the tissue optical properties.

The present study is concerned with the in vitro study of different sized titanium dioxide (TiO 2 ) nanoparticles' (NPs) penetration and accumulation in human normal lung (NL) tissue and lung adenocarcinoma tumor (LAT) tissue by the methods of continuous optical coherence tomography (OCT) monitoring and diffuse reflectance (DR) spectra measurement, and their evaluating the effects of TiO 2 NPs in two sizes (60 nm and 100 nm) and their combination with ultrasound (US) on the optical properties of human NL and LAT tissue. Spectral measurements indicate that TiO 2 NPs penetrate and accumulate into the tissues and thus induce enhancement of DR. The averaged and normalized OCT signal intensity suggests that light penetration depth is significantly enlarged by ultrasound. The average attenuation coefficient of NL tissue changes from 5.10 ± 0.26 mm −1 to 3.12 ± 0.43 mm −1 and 2.15 ± 0.54 mm −1 at 120 min for 60 nm TiO 2 NPs and 60 nm TiO 2 NPs/US treatment, respectively, and from 5.54 ± 0.46 mm −1 to 3.24 ± 0.73 mm −1 and 2.69 ± 0.34 mm −1 at 150 min for 100 nm TiO 2 NPs and 100 nm TiO 2 NPs/US, respectively. The average attenuation coefficient of LAT tissue changes from 9.12 ± 0.54 mm −1 to 4.54 ± 0.39 mm −1 and 3.61 ± 0.38 mm −1 at 120 min for 60 nm TiO 2 NPs and 60 nm TiO 2 NPs/US treatment, respectively, and from 9.79 ± 0.32 mm −1 to 5.12 ± 0.47 mm −1 and 4.89 ± 0.59 mm −1 at 150 min for 100 nm TiO 2 NPs and 100 nm TiO 2 NPs/US, respectively. The results suggest that the optical properties of NL and LAT tissues are greatly influenced by TiO 2 NPs and their combination with ultrasound.

In this study, we presented the research of the penetration of zinc oxide nanoparticles (ZnO NPs) (30 and 90 nm), and electroporation (EP) assisted penetration of the ZnO NPs in the human normal colon (NC) and adenomatous colon (AC) tissues studied with optical coherence tomography (OCT) and diffuse reflectance (DR) measurement. The results have shown that the attenuation coefficient of colon tissue after the application of 30 or 90 nm ZnO NPs alone decreased approximately by 28% and 14% for NC tissue, 35% and 22% for AC tissue, respectively; while the attenuation coefficient of colon tissue after combined application of 30 or 90 nm ZnO NPs/EP decreased approximately by 46% and 30% for NC tissue, and 53% and 42% for AC tissue, respectively. The results illustrate EP can significantly increase the penetration of ZnO NPs in the colon tissue, especially in AC tissue. Through the analysis of attenuation coefficient and reflectance intensity of the colon tissue, we find that the accumulation of the ZnO NPs in the colon tissue greatly influenced the tissue optical properties.