Potential of hybrid iron oxide–gold nanoparticles as thermal triggers for pancreatic cancer therapy

Theranostics are emerging platforms for rapid cancer diagnosis and therapy. Hybrid iron oxide–gold nanoparticles (HNPs) have shown potential as theranostics due to their ability for imaging using MRI, heating using laser irradiation and carrier abilities for drug molecules after surface functionalization. The ability of HNPs to act as localised nano-heaters has been well documented for tumour ablation applications where maximal heating effect is desired. However, the use of HNPs as thermal triggers for drug release requires more control over temperature output and careful consideration of heat dissipation. In this work we report the potential of HNPs to act as localised nano-heaters in vitro and ocument the cellular effect prior and post laser irradiation in human pancreatic adenocarcinoma (BxPC-3) cell lines. The data showed that after incubation of 50 mg mL 1 HNPs, a thermal increase of up to 9 C was observed in the cells after laser irradiation with the total area experiencing heat dissipation from the laser beam being 346 mm2. Although the total temperature experienced by cells was below the perceived temperature for irreversible cell damage, after 24 h significant levels of HSP27 and HSP70 were evident with a drop in cell viability to 85%. This indicated that even with rapid irradiation at low temperatures the cells were undergoing stress. Upon I.T. injection in pancreatic xenograft models, a similar heating capacity was observed at identical concentration which also resulted in bulk tumour dissipation. The findings from this work highlight the factors which must be taken into consideration when designing HNPs as theranostics for heat triggered drug delivery

587 - Thermally triggered theranostics for pancreatic cancer

Conference abstract

The use of iron oxide nanoparticles for pancreatic cancer therapy

Over the last decade major advances have been made in the treatment of cancer such as breast and leukaemia. However, no satisfactory progress has been made in the effective treatment of pancreatic cancer. Treatment of this disease is hindered by resistance of tumor cells to chemotherapy and impaired drug delivery after administration. Pancreatic adenocarcinomas characteristically form a dense stroma, which hinders drug penetration. Increasing administration dosage may provide increased therapeutic effects. However, toxic drug molecules do not act selectively to tumor cells and, as such; a vast range of undesirable side effects can be experienced. Nano-sized formulations of cytotoxic agents have proved to passively target pancreatic adenocarcinomas and promote increased drug efficacy. This is thought to be due to the accumulation via enhanced permeability and retention resulting in deeper drug penetration. Nanoparticles with easily modified surfaces have been investigated extensively in recent years and play a pivotal role in biomedicine. In recent years, magnetic NPs have been increasingly explored for clinical applications, such as drug delivery, magnetic resonance imaging and magnetic fluid hyperthermia for diagnosis and cancer therapy. In comparison with traditional cancer therapy, magnetic field operated therapeutic approaches can treat cancer in an unconventional but more effective and safer way. In this literature review, we highlight the recent advances in the use of iron oxide nanoparticles in pancreatic cancer therapy

Heat Dissipation of Hybrid Iron Oxide-Gold Nanoparticles in an Agar Phantom

Hybrid iron oxide-gold nanoparticles (HNPs) have shown potential in cancer therapy as agents for tumour ablation and thermal switches for targeted drug release. Heat generation occurs by exploitation of the surface plasmon resonance of the gold coating, which usually occurs at the maximum UV absorption wavelength. However, lasers at such wavelength are often expensive and highly specialised. Here, we report the heating and monitoring of heat dissipation of HNPs suspended in agar phantoms using a relatively inexpensive Ng: YAG pulsed 1064 nm laser source. The particles experience heating of up to 40°C with a total area of heat dissipation up to 132.73 mm2 from the 1 mm diameter irradiation point after 60 seconds. This work reports the potential and possible drawbacks of these particles for translation into cancer therapy based on our findings

Enamel Erosion by 15% and 18% Hydrochloric Acid Gels after Different Application Times

Background and Aim: Discolored teeth are among the most common reasons behind seeking esthetic dental treatments. Resin infiltration is a new technique for treatment of white spot lesions (WSLs). In this technique, 15% hydrochloric acid (HCl) is used to cause surface erosion. The aim of this study was to compare the enamel erosion caused by 15% and 18% HCl gels after different application times. Materials and Methods: In this experimental study, sixty sound enamel surfaces were randomly divided into six groups of 10 (G1-G6). G1 specimens were subjected to 15% HCl gel for 75 seconds. G2 and G3 samples were subjected to 15% HCl for 90 and 120 seconds, respectively. G4, G5, and G6 specimens were subjected to 18% HCl for 75, 90, and 120 seconds, respectively. The specimens were then evaluated under a scanning electron microscope (SEM), and the depth of erosion was recorded. Data were analyzed by using one-way analysis of variance (ANOVA) and Tukey’s post-hoc test with a 95% confidence interval. Results: The depth of erosion in 18% HCl groups was greater than that in 15% HCl groups after the same application times (P0.05). Conclusion: The results of this study showed that the application of 18% HCl for 75 seconds is a suitable alternative to the application of 15% HCl for 120 seconds in the resin infiltration technique