The unique properties of nanomaterials have propelled the field of nanomedicine. Nanomaterials have been used as drug delivery, imaging, and photothermal agents for diagnosis and therapy of diseases. Recently, photohyperthermia has attracted great interest from researchers and is actively being investigated as an alternative method of therapy for cancer and even bacteria. Photohyperthermia, or photothermal therapy, is the process of a photothermal agent absorbing light and converting it into heat for the destruction of malignant cells, which is due to elevated temperatures. This technique is non-invasive, can target specific diseased cells for minimal adverse side effects, and can be used in conjunction with other cancer treatments, such as chemotherapy. In this review, we will discuss different nanomaterials that have been implemented as photothermal agents for the treatment of various cancer and bacterial cells. The review will mainly focus on gold nanoparticles, magnetic nanoparticles, and carbon nanotubes. However, other nanomaterials, such as semiconductor nanoparticles and polymer composites, will be briefly discussed. In addition, the photothermal mechanism, current developments, dual imaging and therapy, and future perspectives of nanoparticle-based photohyperthermia will be presented.

Careful control of sol–gel chemistry allows for the encapsulation of water-reactive lithium polysulfides

Sol-gel encapsulation has been used as the basis for detecting cortisol by an immunoassay approach. Previous research showed that antibodies immobilized in the pores of a sol-gel derived silica were able to bind cortisol and be used as an immunosensor. However, this approach was not effective when measuring cortisol levels in human serum because of interference from other fluorescence sources. The present paper describes a protocol which overcomes these limitations and enables sol-gel immunoassays to effectively measure cortisol in human serum over the physiological range of cortisol blood concentrations in an adult (2-28 lg/dL). The method involves a standard additions approach in which various amounts of cortisol are added to the serum. The cortisol concentration values obtained with our sol-gel immunoassay were typically within 10% of the values obtained by traditional analytical methods. The protocol presented here represents a significant contribution to sol-gel sensing and immunoassays in particular, because of the ability to detect an analyte in human serum. In addition, this work reports the first comparison between results from a sol-gel immunosensor and an alternative immuno-binding method for analyte detection.

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The process of encapsulating antibodies in sol-gel was used for sensing various hormones, specifically cortisol, insulin, and C-peptide. A sol-gel optical biosensor for cortisol has been developed for monitoring of crew health on-orbit during space missions. Our studies involving silica sol-gel materials with competitive immunoassays demonstrated linear calibration for cortisol in the range of 2-60 μg/dL, which covers the physiological range of cortisol blood concentration for an adult (2-28 μg/dL). The method of standard additions was used to analyze human serum samples sent to us from a NASA laboratory. Our sol-gel immunosensor values were typically within 20% of the values obtained by NASA-JSC using traditional immuno-binding techniques, with some values having less than a 5% error. Initial results are presented for sensing the hormones insulin and C-peptide.