Design and fabrication of alginate hydrogel nanohybrid as a promising cancer treatment.

Objectives: Basal cell carcinoma (BCC) is the most common form of skin cancer and the most frequently occurring form of all cancers, affecting sun-exposed areas like the face. Surgery is the main treatment, focusing on safe and minimally invasive methods for better outcomes. Technology has enabled the development of artificial skin substitutes for tissue repair. Tissue engineering uses scaffolds to create functional replacements. This project aims to create an alginate-based hydrogel with PEG-coated gold nanoparticles. Materials and Methods: The project extensively explored the modification of alginate hydrogels with PEG-coated gold nanoparticles, involving the synthesis of gold nanoparticles, their integration with the polymer, and the subsequent preparation of the concentrated hybrid hydrogel. Utilizing various physicochemical techniques, such as UV-visible spectroscopy, transmission electron microscopy, dynamic light scattering, zeta potential analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy, the fabrication process was optimized and characterized. Results: The successful synthesis of the hybrid biomaterial was achieved through robust and highly reproducible methods. The MTT assay results offered valuable insights into the biocompatibility and safety of the PEG-coated gold nanoparticle-loaded alginate-based films. The incorporation of PEG-coated gold nanoparticles allowed for potential drug loading on the nanoparticle surface and, consequently, within the hydrogel. Cellular assays were conducted to assess the potential applications of this novel biomaterial. Conclusion: The addition of polyethylene glycol made it possible to load different drugs onto the gold nanoparticles and also within the hydrogel. This makes it a promising choice for potential uses in tissue engineering.

Cobalt ferrite nanoparticle for the elimination of CD133+CD44+ and CD44+CD24-, in breast and skin cancer stem cells, using non-ionizing treatments.

Background: Cancer stem cells (CSCs) are the most challenging issue in cancer treatment, because of their high resistance mechanisms, that can cause tumor recurrence after common cancer treatments such as drug and radiation based therapies, and the insufficient efficiency of common treatments in CSCs removal and the recurrence of tumors after these treatments, it is essential to consider other methods, including non-ionizing treatments likes light-based treatments and magnetic hyperthermia (MHT). Method and material: After synthesis, characterization and investigation, the toxicity of novel on A375 and MAD-MB-231 cell lines, magnetic hyperthermia and light-based treatments were applied. MTT assay and flow cytometry was employed to determine cell survival. the influence of combination therapy on CD44 + CD24-and CD133 + CD44+ cell population, Comparison and evaluation of combination treatments was done respectively using Combination Indices (CIs). Result: The final nanoparticle has a high efficiency in producing hydroxyl radicals and generating heat in MHT. According to CIs, we can conclude that combined using of light-based treatment and MHT in the presence of final synthesized nanoparticle have synergistic effect and a high ability to reduce the population of stem cells in both cell lines compared to single treatments. Conclusion: In this study a novel multi-functional nanoplatform acted well in dual and triple combined treatments, and showed a good performance in the eradication of CSCs, in A375 and MAD-MB-231 cell lines.

Effect of photothermal and photodynamic therapy with cobalt ferrite superparamagnetic nanoparticles loaded with ICG and PpIX on cancer stem cells in MDA-MB-231 and A375 cell lines.

BACKGROUND: Cancer cells are resistant to treatments such as chemotherapy and radiotherapy due to their characteristics such as self-renewal, high proliferation and other resistance mechanisms. To overcome this resistance, we combined a light-based treatment with nanoparticles to get advantage of both PDT and PTT in order to increase efficiency and beater outcome. METHODS AND MATERIAL: After synthesis and characterization of CoFe2O4@citric@PEG@ICG@ PpIX NPs, their dark cytotoxicity concentration was determined with MTT assay. Then light-base treatments were performed by two different light source for MDA-MB-231 and A375 cell lines. After treatment, the results were evaluated 48 h and 24 h after treatment by MTT assay and flow cytometry. Among CSCs defined markers, CD44, CD24 and CD133 are the most widely-used markers in CSC research and are also therapeutic targets in cancers. So we used proper antibodies to detect CSCs. Then indexes like ED50, synergism defined to evaluated the treatment. RESULTS: ROS production and temperature increase have a direct relationship with exposure time. In both cell lines, the death rate in combinational treatment (PDT/PTT) is higher than single treatment and the amount of cells with CD44+CD24- and CD133+CD44+ markers has decreased. According to the synergism index, conjugated NPs show a high efficiency in use in light-based treatments. This index was higher in cell line MDA-MB-231 than A375. And the ED50 is proof of the high sensitivity of A375 cell line compared to MDA-MB-231 in PDT and PTT. CONCLUSION: Conjugated NPs along with combined photothermal and photodynamic therapies may play an important role in eradication CSCs.

Opto-microfluidic assisted synthesis of photo-protoporphyrin (pPP) conjugated to hollow gold-albumin hybrid nanoshells to enhance the efficiency of photodynamic therapy of triple negative breast cancer cells.

INTRODUCTION: Protoporphyrin-IX (PpIX), a photosensitizer used in photodynamic therapy, has limitations due to its hydrophobicity, rapid photobleaching, and low absorption peak in the red region. These limitations make the use of PpIX less effective for photodynamic therapy treatments. In this study, we harnessed the power of microfluidic technology to manipulate the properties of PpIX and quickly synthesize albumin-based hybrid nanoshells with high reproducibility. METHODS AND MATERIAL: To begin with, we designed a microfluidic chip with SolidWorksⓇ software; then the chip was fabricated in Poly(methyl methacrylate) (PMMA) material using micromilling and thermal bonding. We synthesized PpIX-loaded CTAB micelles and subsequently transformed the PpIX structure into photo-protoporphyrin (PPP,) by opto-microfluidic chip (Integrating a microfluidic chip with a light source). Simultaneously with CTAB-PPP synthesis complex, we trapped it in binding sites of bovine serum albumin (BSA). Afterward, we used the same method (without irradiating) to generate a hybrid nanostructure consisting of hollow gold nanoshells (HGN) and BSACTAB-PPP. Then, after physical characterization of nanostructures, the photodynamic effects of the agents (HGNs, CTAB-PpIX, BSA-CTABPpIX, HGN-BSA-CTAB-PpIX, CTAB-PPP, BSA-CTAB-PPP, and HGNs-BSA-CTAB-PPP) were evaluated on MDA-MB-231 and 4T1 cells and the cytotoxic properties of the therapeutic agents after treatment for 24, 48, and 72 hours were investigated using MTT assay. Finally, we analyzed the findings using GraphPad Prism 9.0 software. RESULTS: Results revealed that the opto-microfluidic assisted synthesis of HGN-BSA-CTAB-PPP is highly efficient and reproducible, with a size of 120 nm, a zeta potential of -16 mV, and a PDI index of 0.357. Furthermore, the cell survival analysis demonstrated that the HGNBSA-CTAB-PPP hybrid nanostructure can significantly reduce the survival of MDA-MB-231 and 4T1 cancer cells at low radiation doses (< 10 J/cm2) when exposed to an incoherent light source due to its strong absorption peak at a wavelength of 670 nm. CONCLUSION: This research indicates that developing albumin-based multidrug hybrid nanostructures using microfluidic technology could be a promising approach to design more efficient photodynamic therapy studies.

Optimization of cobalt ferrite magnetic nanoparticle as a theranostic agent: MRI and hyperthermia.

OBJECTIVE: Magnetic nanoparticles (MNPs) are considered a theranostic agent in MR imaging, playing an effective role in inducing magnetic hyperthermia. Since, high-performance magnetic theranostic agents are characterized by superparamagnetic behavior and high anisotropy, in this study, cobalt ferrite MNPs were optimized and investigated as a theranostic agent. METHODS: CoFe2O4@Au@dextran particles were synthesized and characterized by DLS, HRTEM, SEM, XRD, FTIR, and VSM methods. After cytotoxicity evaluation, MR imaging parameters (r1, r2 and r2 / r1) were calculated for these nanostructures. Afterward, magnetic hyperthermia at the frequency of 425 kHz was applied to calculate specific loss power (SLP). RESULTS: Formation of CoFe2O4@Au@dextran was confirmed by UV-Visible spectrophotometry. On the basis of the relaxometric and hyperthermia induction findings of nanostructures in all stages of synthesis, the CoFe2O4@Au@dextran could produce the highest parameters of r2 and r2/r1 and SLP with values ​​of 389.7, 51.2 mM-1 s-1, and 2449 W/g, respectively. CONCLUSION: The formation of multi-core MNPs by dextran coating is expected to improve the magnetic properties of the nanostructure, leading to optimization of theranostic parameters, so that CoFe2O4@Au@dextran NPs can create contrast-enhanced images more than three times the clinical use and require less contrast agent, reducing side effects. Accordingly, CoFe2O4@Au@dextran can be introduced as a suitable theranostic nanostructure with optimal efficiency.

Evaluation of the parameters affecting the loading of anticancer drug Paclitaxel on coated gold nanoparticles for breast cancer treatment.

The purpose of this study is the design and synthesis of gold nanoparticles (GNPs) conjugated with paclitaxel and to investigate the parameters affecting the stability of synthesised nanoparticles with drug delivery capability. Here, synthesised GNPs were coated with polyethylene glycol. Then these particles were conjugated with paclitaxel under different conditions and the physical and structural characteristics, as well as the factors affecting the loading of paclitaxel on nanoparticles, were evaluated by ultraviolet spectrophotometer, fourier transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering and zeta potential apparatus. It was found that pegylated GNPs have a limited loading capacity at the time of 24 h of incubation and the Paclitaxel loading was observed to be pH dependent. The use of these particles in the treatment of breast cancer (MCF7) was also investigated using the MTT test. It was determined that the survival percentage of MCF7 cells in the presence of paclitaxel-bound nanoparticles decreases to about 55% at the maximum measured concentration (690 µM).

The Synergistic Effect of Cold Atmospheric Plasma Mediated Gold Nanoparticles Conjugated with Indocyanine Green as An Innovative Approach to Cooperation with Radiotherapy.

OBJECTIVE: The multimodality treatment of cancer provides a secure and effective approach to improve the outcome of treatments. Cold atmospheric plasma (CAP) has got attention because of selectively target and kills cancer cells. Likewise, gold nanoparticles (GNP) have been introduced as a radiosensitizer and drug delivery with high efficacy and low toxicity in cancer treatment. Conjugating GNP with indocyanine green (ICG) can develop a multifunctional drug to enhance radio and photosensitivity. The purpose of this study is to evaluate the anticancer effects of GNP@ICG in radiotherapy (RT) and CAP on DFW melanoma cancer and HFF fibroblast normal cell lines. MATERIALS AND METHODS: In this experimental study, the cells were irradiated to RT and CAP, alone and in combination with or without GNP@ICG at various time sequences between RT and CAP. Apoptosis Annexin V/PI, MTT, and colony formation assays evaluated the therapeutic effect. Finally, the index of synergism was calculated to compare the results. RESULTS: Most crucially, the cell viability assay showed that RT was less toxic to tumors and normal cells, but CAP showed a significant anti-tumor effect on melanoma cells with selective toxicity. In addition, cold plasma sensitized melanoma cells to radiotherapy so increasing treatment efficiency. This effect is enhanced with GNP@ICG. In comparison to RT alone, the data showed that combination treatment greatly decreased monolayer cell colonization and boosted apoptotic induction. CONCLUSION: The results provide new insights into the development of better approaches in radiotherapy of melanoma cells assisted plasma and nanomedicine.

Surface modification of gold nanoparticles with 6-mercapto-1-hexanol to facilitate dual conjugation of protoporphyrin IX and folic acid for improving the targeted photochemical internalization.

Objectives: Photochemical internalization (PCI) is an important type of photodynamic therapy for delivering macromolecules into the cytosol by the endocytosis process. In this study, 6-mercapto-1-hexanol (MH) was used to functionalize the gold nanostructure as a primer for surface modification to improve conjugation of multi-agents such as protoporphyrin IX (Pp-IX) and folic acid with gold nanoparticles (PpIX/FA-MH-AuNP) to facilitate the photochemical internalization. Materials and Methods: After surface modification of AuNPs with MH, PpIX and FA are bonded to the surface of the MH-AuNPs through the coupling reaction to produce the desired conjugated AuNPs. In the next step, the synthesized nanostructures were characterized by different methods. Finally, after selecting specific concentrations, light treatments were applied and cell survival was measured based on MTT analysis. Also, in order to better study the morphology of the cells, they were stained by the Giemsa method. The SPSS 16 software was used for data analysis. Results: By surface modification of the nanostructure with MH and then conjugation of FA to it, the incubation time of the drug in PpIX/FA-MH-AuNP was reduced from 3 hr to 30 min. Also, at each light dose, cell death in the presence of PpIX/FA-MH-AuNP was significantly reduced compared with unconjugated conditions (P<0.001). Under these conditions, the ED50 for PpIX and PpIX-MH-AuNP and PpIX/FA-MH-AuNP at a concentration of 2.5 µg/ml is 8.9, 9.1, and 6.17 min, respectively. Conclusion: The results show that the PCI of PpIX/FA-MH-AuNP increases the selective phototoxicity efficiency on cancer cells compared with the conventional process of photodynamic therapy.

Sonodynamic Therapy Using Dacarbazine-Loaded AuSiO2 Nanoparticles for Melanoma Treatment: An In-Vitro Study on the B16F10 Murine Melanoma Cell Line.

The use of nanoparticles as a sonosensitizer in cancer sonodynamic therapy has been gaining attention because of their great advantages in drug delivery applications. By conjugating chemotherapy agents with nanoparticles, we can develop a drug delivery platform, control drug release and improve the outcome of treatments. The in-vitro study described here evaluates the combination of AuSiO2 nanoparticles and dacarbazine (DTIC@AuSiO2) as a sonosensitizer for sonodynamic therapy of melanoma. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays revealed that the viability of B16F10 melanoma cells was significantly inhibited by the increase in apoptosis induction in treatment with DTIC@AuSiO2 nanoparticles under ultrasound exposure compared with treatment with the free DTIC or AuSiO2 nanoparticles. The sonosensitization activity of AuSiO2 nanoparticles and greater uptake of DTIC by tumor cells after loading in DTIC@AuSiO2 nanoparticles inhibited the proliferation of melanoma tumor cells effectively. In conclusion, the DTIC@AuSiO2 nanoparticles established in this study could represent a good drug delivery and sonosensitizer platform for use in melanoma sonodynamic therapy.

Study of the Parameters Affecting the Loading of Fluorescein on Coated Gold Nanoparticles: Promising Nanostructure for Cancer Diagnosis.

BACKGROUND: Recent advances in nanotechnology have led to the use of nanomaterials in the diagnosis of cancer by imaging techniques. OBJECTIVE: This study aimed to synthesize fluorescein-conjugated gold nanoparticles and study the parameters affecting the loading of fluorescein on synthesized coated gold nanoparticles with the ability to be used in medical diagnostic methods. METHODS: The synthesized gold nanoparticles were functionalized with polyethylene glycol. Then, these particles were conjugated with fluorescein under different conditions. To investigate the optical and structural features as well as the factors affecting the loading, the nanoparticles were evaluated by ultraviolet-visible, fluorescence and FT-IR spectrophotometer, fluorescence spectrophotometer, transmission electron microscopy, dynamic light scattering, and zeta potential measuring device. Also, the use of these particles in cancer diagnosis on the skin melanoma cell (B16F10) was examined using a fluorescence microscope. RESULTS: PEG-coated spherical gold nanoparticles were synthesized as a carrier for the fluorescein dye detector. The coating agent concentration, incubation time, temperature, and pH of the medium affected the loading efficiency of fluorescein on the nanoparticles. Also, optimal conditions for use in the diagnostic applications were investigated. Ten micromolar of the sample were selected for cell imaging studies. The fluorescence signal of B16F10 cells containing nanoparticles was relatively strong, indicating the amount of nanoparticles uptaken by the cells. CONCLUSION: The results showed that by designing fluorescent gold nanoparticles with fluorescein as fluorescent detectors and considering their diagnostic importance, an efficient way to diagnose incurable diseases can be found.

Superparamagnetic cobalt ferrite nanoparticles as T2 contrast agent in MRI: in vitro study.

Superparamagnetic cobalt ferrite nanoparticles (CoFe2O4) possess favourite advantages for theranostic applications. Most of previous studies reported that CoFe2O4 magnetic nanoparticles (MNPs) are suitable candidates for induction of hyperthermia and transfection agents for drug delivery. The present study synthesized and investigated the potential use of CoFe2O4 as a contrast agent in magnetic resonance imaging (MRI) by using a conventional MRI system. The CoFe2O4 were synthesized using co-precipitation method and characterized by TEM, XRD, FTIR, EDX and VSM techniques. Relaxivities r1 and r2 of CoFe2O4 were then calculated using a 1.5 Tesla clinical magnetic field. The cytotoxicity of CoFe2O4 was evaluated by the MTT assay. Finally, the optimal concentrations of MNPs for MRI uses were calculated through the analysis of T2 weighted imaging cell phantoms. The superparamagnetic CoFe2O4 NPs with an average stable size of 10.45 nm were synthesized. Relaxivity r1,2 calculations resulted in suitable r2 and r2/ r1 with values of 58.6 and 51 that confirmed the size dependency on relaxivity values. The optimal concentration of MNPs for MR image acquisition was calculated as 0.154 mM. Conclusion: CoFe2O4 synthesized in this study could be considered as a suitable T2 weighted contrast agent because of its high r2/r1 value.

Effect of targeted gold nanoparticles size on acoustic cavitation: An in vitro study on melanoma cells.

When a liquid is irradiated with high intensities of ultrasound irradiation, acoustic cavitation occurs. Since cavitation can be fatal to cells, it is utilized to destroy cancer tumors. Considering cavitation onset and bubbles collapse, the required ultrasonic intensity threshold can be significantly decreased in the presence of nanoparticles in a liquid. The effects of gold nanoparticles size on acoustic cavitation were investigated in this in vitro study. For this purpose, ultrasonic waves were used at intensities of 0.5, 1 and 2 W/cm2 and frequency of 1 MHz in the presence of F-Cys-GNPs with 15, 23 and 79 nm sizes and different concentrations (0.2, 1 and 5 µg/ml) in order to determine their effects on the viability of melanoma cells. This was performed at different incubation times 12, 24 and 36 h. The viability of melanoma cells decreased at higher concentrations and sizes of F-Cys-GNPs. The lowest viability of melanoma cells was seen in those containing 79, 23, and 15 nm F-Cys-GNPs. This finding could be explained from the concept that the nucleation sites on the surface of GNPs increase with an increase in size of GNPs, which results in an increase in the number of cavitation bubbles. Acoustic cavitation in the presence of gold nanoparticles can be used as a way for improving therapeutic effects on the tumors.

Dual-energy CT imaging of nasopharyngeal cancer cells using multifunctional gold nanoparticles.

The purpose of this study is to measure the concentration of gold nanoparticles (AuNPs) attached to folic acid through cysteamin as the linker (FA-Cys-AuNPs) and AuNPs in KB human nasopharyngeal cancer cells using dual-energy CT (DECT). In this study, nanoparticles with a size of ∼15 nm were synthesized and characterised using UV-Vis, TEM, FTIR and ICP-OES analyses. The non-toxicity of nanoparticles was confirmed by MTT assay under various concentrations (40-100 µg/ml) and incubation times (6, 12 and 24 h). To develop an algorithm for revealing different concentrations of AuNPs in cells, a corresponding physical phantom filled with 0.5 ml vials containing FA-Cys-AuNPs was used. The CT scan was performed at two energy levels (80 and 140 kVp). One feature of DECT is material decomposition, which allows separation and identification of different elements. The values obtained from the DECT algorithm were compared with values quantitatively measured by ICP-OES. Cells were also incubated with AuNPs and FA-Cys-AuNPs at different concentrations and incubation times. Subsequently, by increasing the incubation time in the presence of FA-Cys-AuNPs, in comparison with AuNPs, DECT pixels were increased. Thus, FA-Cys-AuNPs could be a suitable candidate for targeted contrast agent in DECT molecular imaging of nasopharyngeal cancer cells.

Targeted gold nanoparticles enable molecular CT imaging of head and neck cancer: An in vivo study.

The development of various cost-effective multifunctional contrast agent for specific targeting molecular imaging of tumors presents a great challenge. We report here the in vivo targeting imaging of folic acid (FA) gold nanoparticles (AuNPs) through cysteamine (Cys) linking for targeted of human nasopharyngeal head and neck cancer by computed tomography (CT). The toxicity of nanoparticles in kidney, heart, spleen, brain and liver was evaluated by H&E (hematoxylin and eosin) assay. We showed that the formed FA-Cys-AuNPs with an Au core size of ˜13 nm are non-cytotoxic in the particle concentration of 3 × 103 µg/ ml. The nude mice were scanned using a 64-slice CT scan with parameters (80 kVp, slice thickness: 0.625 mm, mAs: 200, pitch: 1). CT scan was performed before and after (Three and six hours) I.V (Intra Venous) injection of AuNPs and FA-Cys-AuNPs. The distribution of nanoparticles in the nude mice was evaluated by imaging and coupled plasma optical emission spectrometry (ICP-OES) analysis. The findings clearly illustrated that a small tumor, which is undetectable via computed tomography, is enhanced by X-ray attenuation and becomes visible (4.30-times) by the molecularly targeted AuNPs. It was further demonstrated that active tumor cells targeting (FA-Cys-AuNPs) is more specific and efficient (2.03-times) than passive targeting AuNPs. According to the results, FA-Cys-AuNPs can be employed as a promising contrast agent in CT scan imaging and maybe in radiotherapy that require enhanced radiation dose.

Microtubule network as a potential candidate for targeting by gold nanoparticle-assisted photothermal therapy.

Photothermal therapy is achieving ever-increasing attention as a promising method for killing cancer cells. Although, gold nanoparticles are regarded as one of the most effective photothermal therapy agents, the mechanisms underlying their action have to be addressed. Moreover, studies have showed that gold nanoparticles induce apoptosis in treated cultures. Hence, in this study, we investigated the interaction of folic acid functionalized gold nanoparticles and gold-shelled Fe3O4 nanoparticles with microtubule and microtubule associated protein tau in order to introduce intracellular targets of these nanoparticles and provide a holistic view about the mechanism of action of gold nanoparticles used in photothermal therapy. Various spectroscopic methods were used to find gold nanoparticles interaction with Tubulin and Tau. Our results indicated that these gold nanoparticles interact with both Tau and Tubulin and their affinity increases as temperature rises. Also, the results illustrated that quenching mechanism for gold nanoparticles interaction with Tubulin and Tau was static. The hydrophobic interaction was determined as driving force for gold nanoparticles binding to Tubulin and Tau. Moreover, it was showed that both type of gold nanoparticles stabilize microtubule polymers. These results suggest Tau and Tubulin as intracellular target of gold nanoparticles and propose that microtubule network is at the heart of apoptosis mechanisms initiated by photothermal therapy.

Folate-modified and curcumin-loaded dendritic magnetite nanocarriers for the targeted thermo-chemotherapy of cancer cells.

A novel multifunctional nanoplatform constructed from methoxy-PEGylated poly(amidoamine) (PAMAM) generation 3 dendrimers with superparamagnetic iron oxide nanoparticles (SPIONs) entrapped in their core, containing curcumin as the payload drug and folic acid (folate) as the targeting ligand (abbreviated as FA-mPEG-PAMAM G3-CUR@SPIONs), is presented in this study. SPIONs entrapped in the core of the nanocomplex may act as a hyperthermia agent and generate localized heat upon excitation with an alternating magnetic field (AMF), thus enabling a thermo-chemotherapy strategy for cancer treatment. Accordingly, the cytotoxic effect and the mode of cell death triggered by the nanocomplex in combination with AMF were evaluated on two different cancer cell lines with various folate receptor (FR) expression levels, including KB nasopharyngeal cancer cells overexpressing FRs as the model and MCF-7 breast cancer cells with low level of FRs as the blank sample. The obtained results showed that KB cell death was greater than the cell death observed in MCF-7 cells. Moreover, a majority of cell death in both cell lines were related to apoptosis when the folate-modified nanocomplex was used instated of the non-folate-modified nanocomplex. Therefore, functionalizing the nanocomplex with folate modulated the response to thermo-chemotherapy by shifting the cell death pathways toward apoptosis.

Folic acid-cysteamine modified gold nanoparticle as a nanoprobe for targeted computed tomography imaging of cancer cells.

Development of various cost-effective multifunctional nanoprobes for efficient targeted molecular imaging of tumors remains a great challenge in medicine. Herein, we report a simple method of forming folic acid-targeted multifunctional gold nanoparticles via cost-effective cysteamine as a template for tumor molecular computed tomography (CT) imaging technique. The formed multifunctional cysteamine-folic acid conjugated gold nanoparticles (FA-Cys-AuNPs) were characterized via different techniques. Colony assay, hematoxylin and eosin (H&E), MTT, and flow cytometry analysis were used to evaluate the cytocompatibility of the particles. We showed that the formed FA-Cys-AuNPs with an Au core size of ~15 nm are non-cytotoxic in a given concentration range and revealed greater X-ray attenuation intensity than iodine-based contrast agent under the same concentration of the active element. At 80 kVp, FA-Cys-AuNPs enable 1.77-times greater contrast per unit mass compared with iodine at a concentration of 2000 µg/ml, and importantly, the developed FA-Cys-AuNPs can be used as a contrast media for targeted CT imaging of folic acid receptor-expressing cancer cells in vitro. CT values of the targeted cells were 2-times higher than that of non-targeted cells at 80 kVp. These findings propose that the designed FA-Cys-AuNPs can be used as a promising contrast agent for molecular CT imaging. This data can be also considered for the application of gold nanostructures in radiation dose enhancement where nanoparticles with high X-ray attenuation are applied.

Selective apoptosis induction in cancer cells using folate-conjugated gold nanoparticles and controlling the laser irradiation conditions.

In this study, we explained in detail a targeted nano-photo-thermal therapy (NPTT) method to induce selective apoptosis in cancer cells. Folate-conjugated gold nanoparticles (F-AuNPs) were synthesized by tailoring the surface of AuNPs with folic acid to enhance the specificity of NPTT. KB cancer cells, as a folate receptor over-expressing cell line, and L929 normal cells with low level of folate receptors were incubated with the synthesized F-AuNPs and then irradiated with various laser intensities and exposure durations. Following various regimes of NPTT, we assessed the level of cell viability and the ratio of apoptosis/necrosis. No significant cytotoxicity was observed for both cell lines at concentrations up to 40 µM of F-AuNPs. Moreover, no significant cell lethality occurred for various laser irradiation conditions. The viability of KB and L929 cells incubated with F-AuNPs (40 µM; 6 h) and then irradiated by laser (1 W/cm2; 2 min) was 57 and 83%, respectively. It was also demonstrated that the majority of cancer cell death is related to apoptosis (41% apoptosis of 43% overall cell death). In this process of F-AuNPs based NPTT, it may be concluded that the main factor determining whether a cell dies due to apoptosis or necrosis depends on laser irradiation conditions. In this study, we explained in detail a targeted nano-photo-thermal therapy (NPTT) method to induce selective apoptosis in cancer cells.

Selective heat generation in cancer cells using a combination of 808 nm laser irradiation and the folate-conjugated Fe2O3@Au nanocomplex.

Photothermal therapy (PTT) is a nanotechnology-assisted cancer hyperthermia approach in which the interaction between laser light and plasmonic nanoparticles (NPs) generates localized heating. The exploitation of plasmonic NPs in association with active targeting moieties causes the preferential accumulation of NPs inside cancer cells, thereby providing targeted PTT. Herein, we evaluate the effect of folic acid (FA) as an active targeting agent in enhancing the photothermal efficiency of multifunctional Iron (III) Oxide (Fe2O3)@Au core- shell NPs. Fe2O3@Au NPs were synthesized, modified with FA and then characterized. Human nasopharyngeal (KB) cancer cells were treated with different concentrations of Fe2O3@Au, with and without FA modification and the temperature rise profiles of the cells were measured upon administration of the near-infrared (NIR) laser (808 nm, 6 W/cm2, 10 min). The recorded temperature profiles of the cells were used for thermal dose calculation. Finally, the level of induced apoptosis was determined by flow cytometry using an annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit. The characterization data showed that the Fe2O3@Au NPs are spherical, with a hydrodynamic size of 33 nm. The data corroborated the successful conjugation of the NPs with FA. The thermometry results indicated the superior temperature elevation rate of the cells in the presence of the NPs upon NIR irradiation. Meanwhile, the higher heating rate and the higher thermal dose were obtained for the cells exposed to FA-targeted Fe2O3@Au rather than the non-targeted nanocomplex. Flow cytometry studies revealed that FA-targeted Fe2O3@Au induced higher level of apoptosis than non-targeted Fe2O3@Au NPs. In conclusion, our findings suggest that the synthesized FA-targeted Fe2O3@Au NP has high potentials to be considered as an efficient thermosensitizer in the process of targeted cancer hyperthermia.