Optimizing the performance of silica nanoparticles functionalized with a near-infrared fluorescent dye for bioimaging applications.

Modified fluorescent nanoparticles continue to emerge as promising candidates for drug delivery, bioimaging, and labeling tools for various biomedical applications. The ability of nanomaterials to fluorescently label cells allow for the enhanced detection and understanding of diseases. Silica nanoparticles have a variety of unique properties that can be harnessed for many different applications, causing their increased popularity. In combination with an organic dye, fluorescent nanoparticles demonstrate a vast range of advantageous properties including long photostability, surface modification, and signal amplification, thus allowing ease of manipulation to best suit bioimaging purposes. In this study, the Stöber method with tetraethyl orthosilicate (TEOS) and a fluorescent dye sulfo-Cy5-amine was used to synthesize fluorescent silica nanoparticles. The fluorescence spectra, zeta potential, quantum yield, cytotoxicity, and photostability were evaluated. The increased intracellular uptake and photostability of the dye-silica nanoparticles show their potential for bioimaging.

Neurological and Neurobehavioral Disorders Associated with Toxoplasma gondii Infection in Humans.

The intracellular parasite Toxoplasma gondii is estimated to infect up to 30% of the world population, leading to lifelong chronic infection of the brain and muscle tissue. Although most latent T. gondii infections in humans have traditionally been considered asymptomatic, studies in rodents suggest phenotypic neurological changes are possible. Consequently, several studies have examined the link between T. gondii infection and diseases such as schizophrenia, epilepsy, depression, bipolar disorder, dysphoria, Alzheimer's disease, Parkinson's disease, and obsessive-compulsive disorder (OCD). To date, there is varying evidence of the relationship of T. gondii to these human neurological or neurobehavioral disorders. A thorough review of T. gondii literature was conducted to highlight and summarize current findings. We found that schizophrenia was most frequently linked to T. gondii infection, while sleep disruption showed no linkage to T. gondii infection, and other conditions having mixed support for a link to T. gondii. However, infection as a cause of human neurobehavioral disease has yet to be firmly established.