The history of photodetection and photodynamic therapy

Recent Progress in Nanomaterial-Based Biosensors and Theranostic Nanomedicine for Bladder Cancer

Bladder cancer (BCa) is one of the most expensive and common malignancies in the urinary system due to its high progression and recurrence rate. Although there are various methods, including cystoscopy, biopsy, and cytology, that have become the standard diagnosis methods for BCa, their intrinsic invasive and inaccurate properties need to be overcome. The novel urine cancer biomarkers are assisted by nanomaterials-based biosensors, such as field-effect transistors (FETs) with high sensitivity and specificity, which may provide solutions to these problems. In addition, nanomaterials can be applied for the advancement of next-generation optical imaging techniques and the contrast agents of conventional techniques; for example, magnetic resonance imaging (MRI) for the diagnosis of BCa. Regarding BCa therapy, nanocarriers, including mucoadhesive nanoparticles and other polymeric nanoparticles, successfully overcome the disadvantages of conventional intravesical instillation and improve the efficacy and safety of intravesical chemotherapy for BCa. Aside from chemotherapy, nanomedicine-based novel therapies, including photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), and combination therapy, have afforded us new ways to provide BC therapy and hope, which can be translated into the clinic. In addition, nanomotors and the nanomaterials-based solid tumor disassociation strategy provide new ideas for future research. Here, the advances in BCa diagnosis and therapy mentioned above are reviewed in this paper.

The application of antimicrobial photodynamic therapy (aPDT) in dentistry: a critical review

In recent years there have been an increasing number of in vitro and in vivo studies that show positive results regarding antimicrobial photodynamic therapy (aPDT) used in dentistry. These include applications in periodontics, endodontics, and mucosal infections caused by bacteria present as biofilms. Antimicrobial photodynamic therapy is a therapy based on the combination of a non-toxic photosensitizer (PS) and appropriate wavelength visible light, which in the presence of oxygen is activated to produce reactive oxygen species (ROS). ROS induce a series of photochemical and biological events that cause irreversible damage leading to the death of microorganisms. Many light-absorbing dyes have been mentioned as potential PS for aPDT and different wavelengths have been tested. However, there is no consensus on a standard protocol yet. Thus, the goal of this review was to summarize the results of research on aPDT in dentistry using the PubMed database focusing on recent studies of the effectiveness aPDT in decreasing microorganisms and microbial biofilms, and also to describe aPDT effects, mechanisms of action and applications.

Nano-cerium-element-doped titanium dioxide induces apoptosis of Bel 7402 human hepatoma cells in the presence of visible light

AIM

To investigate the apoptotic effect of photoexcited titanium dioxide (TiO(2)) nanoparticles in the presence of visible light on human hepatoma cell line (Bel 7402) and to study the underlying mechanism.

METHODS

Cerium-element-doped titanium dioxide nanoparticles were prepared by impregnation method. Bel 7402 human hepatoma cells were cultured in RPMI 1640 medium in a humidified incubator with 50 mL/L CO(2) at 37 centigrade. A 15 W fluorescent lamp with continuous wavelength light was used as light source in the photocatalytic test. Fluorescence morphology and agarose gel eletrophoresis pattern were performed to analyze apoptotic cells.

RESULTS

The Ce (IV)-doped TiO(2) nanoparticles displayed their superiority. The adsorption edge shifted to the 400-450 nm region. With visible light illuminated for 10 min, 10 microg/cm(3) Ce (IV)-doped TiO(2) induced micronuclei and significant apoptosis in 4 and 24 h, respectively. Hochest 33258 staining of the fixed cells revealed typical apoptotic structures (apoptotic bodies), agarose gel electrophoresis showed typical DNA ladder pattern in treated cells but not in untreated ones.

CONCLUSION

Ce (IV) doped TiO(2) nanoparticles can induce apoptosis of Bel 7402 human hepatoma cells in the presence of visible light.