The use of Z-scan technique for determination of biochemical parameters in children with solid tumors or leukemias supplemented or not with selenium

Investigating the Z-scan technique for quantifying circulating cell-free DNA (ccfDNA) extracted from blood plasma as a potential biomarker for various cancers

The Z-scan technique is a nonlinear optical method that has found applications in characterizing various materials, particularly those exhibiting nonlinear optical response (NLOR). This study applies the continuous wave (CW) Z-scan technique to examine the NLOR in terms of the nonlinear optical phase shifts(ΔΦ0) exhibited by the ccfDNA extracted from blood plasma samples collected from a group constituting 30 cancer-diagnosed patients and another group constituting 30 non-diagnosed individuals. The cancer group exhibited significantly higherΔΦ0versus incident power slopes compared to the non-cancer group (0.34 versus 0.12) providing a clear distinction between the two groups. The receiver operating characteristic (ROC) curve analysis of the results indicates a clear separation between cancer and non-cancer groups, along with a 94% accuracy rate of the data. The Z-scan results are corroborated by spectrophotometric analysis, revealing a consistent trend in the concentration values of ccfDNA samples extracted from both cancerous and non-cancerous samples, measuring 3.24 and 1.41 respectively. Additionally, more sensitive fluorometric analyses of the respective samples demonstrate significantly higher concentrations of ccfDNA in the cancer group, further affirming the correlation with the Z-scan results. The study suggests that the Z-scan technique holds promise as an effective method for cancer detection, potentially contributing to improved oncology diagnosis and prognosis in the future.

Nonlinear optical response of cancer cells following conventional and nano-technology based treatment strategies: Results of chemo-, thermo- and radiation therapies

BACKGROUND

Although traditional treatments are able to increase cancer survival rate, undesirable impact on off-target tissues are considered a limitation of these approaches. Nanotechnology-based treatments have been proposed as a possible option to enhance targeting., Further,current methods for evaluating cellular damage, are time consuming, highly dependent on the operator skills, and expensive. The aim of this study was to evaluate the capability of nonlinear optical response of cells to determine cellular damages during conventional and nano-technology based treatments.

METHODS

Three different cancer cell lines, CT26, KB, and MCF-7 were used in this study. The alginate hydrogel co-loaded with cisplatin and Au nanoparticle (ACA) nanocomplex and gold-coated iron oxide nanoparticle (Au@IONP) were considered for chemo- and chemo-photothermal therapies, and thermo-radiation therapy, respectively. The sign and value of nonlinear optical absorption coefficient and imaginary part of the third-order nonlinear susceptibility of cells were computed. MTT assay was utilized as a reference method.

RESULTS

The value of nonlinear optical indices increased with increasing cellular damage and cell death. The linear regression analysis indicated high correlation between nonlinear optical indices and MTT results, in all treatments.

CONCLUSION

The nonlinear optical indices are robust from confounding factors, namely treatment approach (traditional and nano-technology based), treatment modality (chemotherapy, thermotherapy, photothermal therapy, and radiation therapy), and cell types. Nonlinear optical properties of cells can be used as a rapid estimation method for cell damage, at the nanoscale level.

Z-scan method to measure the nonlinear optical behavior of cells for evaluating the cytotoxic effects of chemotherapy and hyperthermia treatments

The effects of new treatments must be investigated in vitro before using clinically or in vivo. The aim of this study was to introduce the Z-scan technique as a fast, accurate, inexpensive, and safe in vitro method to distinguish the cytotoxic effects of various treatments. C6 and OLN-93 cell lines were prepared and treated with Temozolomide (TMZ), radiofrequency hyperthermia (HT), and chemo-hyperthermia (HT+TMZ). The cytotoxic effects of different treatments on both cell lines were evaluated using colony formation assay and Z-scan method. The results of colony assay showed that the surviving fraction (SF) of C6 cells treated with TMZ, HT, and HT + TMZ were significantly decreased compared to the control group. Whereas, hyperthermia treatment had no significant effect on the SF of OLN-93 cells. The results of Z-scan technique indicated that the control group of C6 cells had the negative nonlinear refractive index (n₂). Whereas, the C6 cells treated with HT, TMZ, and HT + TMZ had the positive n₂ index. The sign of n₂ index in the control and HT groups of OLN-93 cells was positive but treatment of cells with TMZ and HT + TMZ changed the sign of it. Moreover, with increasing the cytotoxic effects of different treatments, the SF value of both cell lines decreased and the magnitude of n₂ index increased. The results of Z-scan technique were completely in line with the results of colony assay. Therefore, Z-scan method could distinguish the cytotoxic effects of various treatments by examining the nonlinear optical properties of the samples.

Magneto-plasmonic nanoparticle mediated thermo-radiotherapy significantly affects the nonlinear optical properties of treated cancer cells

In order to determine the level of cell damage in cancerous cells, current cytogenetic tests have limitations such as time consumption and high cost. The aim of this study was to demonstrate the ability of nonlinear refractive (NLR) index as a predictor of breast cell damage caused by magneto-plasmonic nanoparticle based thermo-radiotherapy treatments. MCF-7 breast cancer cells were subjected individually to the treatment of radiation, radio-frequency (RF) hyperthermia, and radiation + RF hyperthermia. These treatments were repeated in the presence of magneto-plasmonic nanoparticle (Au@IONP). The MTT and nonlinear optical assays were used to evaluate the damage induced by different treatment modalities. The results of MTT were correlated with Z-scan, as the magnitude of nonlinear refraction increased with higher intensity of induced cell damages. In this regard, the lowest cell viability (38 %,) and highest magnitude of NLR index (+28.12) were obtained from combination of radiation (at 4 Gy dose) and hyperthermia treatment in the presence of nanoparticles. The proposed optical index (NLR) indicated high capability and can be used as an auxiliary tool to monitor induced cell damage during different treatment strategies. This technique is fast, noninvasive, does not impose cost, and finally does not waste materials.

The capability of nonlinear optical characteristics as a predictor for cellular uptake of nanoparticles and cell damage

Current methods for determining the cellular effects of a treatment modality need expensive materials and much time to provide a researcher with results. The aim of this study was to evaluate the potential of nonlinear optical characteristics of cancer cells using Z-scan technique to monitor the level of cellular uptake and cell damage caused by a nanotechnology based treatment modality. Two nanocomplexes were synthesized and characterized. The first one was made of alginate hydrogel co-loaded with cisplatin and gold nanoparticles (AuNPs) named as ACA nanocomplex. The second one, named as AA nanocomplex, was the same as ACA, but without cisplatin and this AA nanocomplex was considered as the control for ACA. Different groups of CT26 mouse colon cancer cell line received various treatments of cisplatin, ACA, and AA nanocomplexes and then the samples were prepared for Z-scan studies. The MTT assay was used to evaluate the cytotoxicity induced by different treatment modalities. Transmission electron microscopy (TEM) and inductively coupled plasma-mass spectrometry (ICP-MS) were used for qualitative and quantitative assessments of the level of AuNPs cellular uptake. The trend of nonlinear optical properties changes for treated cells was in agreement with MTT, TEM and ICP-MS results. Z-scan technique was able to successfully indicate the occurrence of cell damage. It was also capable to determine the intensity of cell damage induced by ACA nanocomplex in comparison to free cisplatin. Furthermore, Z-scan results showed that it was able to discriminate the differences of optical properties of the cells incubated with ACA nanocomplex for various incubation times. Nonlinear optical characteristics of a cell may be considered as a reliable indicator to predict the level of cellular effects induced by a nanotechnology based treatment modality. The protocol suggested in this article does not waste materials, not take much time to provide the results, and it is inexpensive technique.