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Targeted, on-demand delivery has been of interest using materials responsive to environmental stimuli. A delivery technique based on precise release of aqueous microdroplets from a liquid crystal (LC) medium with contactless stimulation is presented. A nematic LC is doped with a photothermal dye that produces heat under near IR light exposure. The heat is used to overcome the elastic strains in the LC phase, promoting the release of initially entrapped water droplets to the neighboring aqueous solution. Designing the geometry of LC-based emulsions and tuning the light intensity and position allows for manipulation of the release in two distinct modes defined as pulsated and continuous. In the pulsated mode, water droplets are released transiently from the casted water-in-LC emulsion layer based on sweeping by the moving isotropic-nematic phase boundary controlled by light. In the continuous mode, water droplets are ejected continuously from a droplet-shaped water-in-LC emulsion, due to a heating-induced internal flow controlled by light. The droplet release by contactless stimulation is used for the on-demand dosing of dopamine and its oxidizing reagent from isolated reservoirs to obtain an in situ reaction signal for a hydrogen peroxide assay. A new dual-mode release system developed with photothermal LCs holds potential in drug release, controlled mixing, and photothermal therapy.

Bacterial contamination is a severe issue that affects medical devices, hospital tools and surfaces. When microorganisms adhere to a surface (e.g., medical devices or implants) they can develop into a biofilm, thereby becoming more resistant to conventional biocides and disinfectants. Nanoparticles can be used as an antibacterial agent in medical instruments or as a protective coating in implantable devices. In particular, attention is being drawn to photothermally active nanoparticles that are capable of converting absorbed light into heat. These nanoparticles can efficiently eradicate bacteria and biofilms upon light activation (predominantly near the infrared to near-infrared spectral region) due a rapid and pronounced local temperature increase. By using this approach new, protective, antibacterial surfaces and materials can be developed that can be remotely activated on demand. In this review, we summarize the state-of-the art regarding the application of various photothermally active nanoparticles and their corresponding nanocomposites for the light-triggered eradication of bacteria and biofilms.

"This is the peer reviewed version of the following article: Hernández Montoto, Andy, Antoni Llopis-Lorente, Mónica Gorbe, José M. Terrés, Roberto Cao Milán, Borja Díaz de Greñu, María Alfonso, et al. 2019. Janus Gold Nanostars Mesoporous Silica Nanoparticles for NIR-Light-Triggered Drug Delivery. Chemistry A European Journal 25 (36). Wiley: 8471 78. doi:10.1002/chem.201900750, which has been published in final form at https://doi.org/10.1002/chem.201900750. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.", [EN] Janus gold nanostar-mesoporous silica nanoparticle (AuNSt-MSNP) nanodevices able to release an entrapped payload upon irradiation with near infrared (NIR) light were prepared and characterized. The AuNSt surface was functionalized with a thiolated photolabile molecule (5), whereas the mesoporous silica face was loaded with a model drug (doxorubicin) and capped with proton-responsive benzimidazole-beta-cyclodextrin supramolecular gatekeepers (N 1). Upon irradiation with NIR-light, the photolabile compound 5 photodissociated, resulting in the formation of succinic acid, which induced the opening of the gatekeeper and cargo delivery. In the overall mechanism, the gold surface acts as a photochemical transducer capable of transforming the NIR-light input into a chemical messenger (succinic acid) that opens the supramolecular nanovalve. The prepared hybrid nanoparticles were non-cytotoxic to HeLa cells, until they were irradiated with a NIR laser, which led to intracellular doxorubicin release and hyperthermia. This induced a remarkable reduction in HeLa cells viability.

"This is the peer reviewed version of the following article: Hernández Montoto, Andy, Antoni Llopis-Lorente, Mónica Gorbe, José M. Terrés, Roberto Cao Milán, Borja Díaz de Greñu, María Alfonso, et al. 2019. Janus Gold Nanostars Mesoporous Silica Nanoparticles for NIR-Light-Triggered Drug Delivery. Chemistry A European Journal 25 (36). Wiley: 8471 78. doi:10.1002/chem.201900750, which has been published in final form at https://doi.org/10.1002/chem.201900750. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.", [EN] Janus gold nanostar-mesoporous silica nanoparticle (AuNSt-MSNP) nanodevices able to release an entrapped payload upon irradiation with near infrared (NIR) light were prepared and characterized. The AuNSt surface was functionalized with a thiolated photolabile molecule (5), whereas the mesoporous silica face was loaded with a model drug (doxorubicin) and capped with proton-responsive benzimidazole-beta-cyclodextrin supramolecular gatekeepers (N 1). Upon irradiation with NIR-light, the photolabile compound 5 photodissociated, resulting in the formation of succinic acid, which induced the opening of the gatekeeper and cargo delivery. In the overall mechanism, the gold surface acts as a photochemical transducer capable of transforming the NIR-light input into a chemical messenger (succinic acid) that opens the supramolecular nanovalve. The prepared hybrid nanoparticles were non-cytotoxic to HeLa cells, until they were irradiated with a NIR laser, which led to intracellular doxorubicin release and hyperthermia. This induced a remarkable reduction in HeLa cells viability.

Traumatic Brain Injury or TBIs are common across both military and civilian populations. In the US, the CDC reports an annual TBI incidence of 1.7 million, with 580,000 TBI-associated deaths in the decade 1997-2007. Low-level laser therapy (LLLT) is unique among the many therapies tested clinically for TBI. Its mechanism of action is biostimulation by nearinfrared (NIR) light. In the proposed work, through both clinical and preclinical investigations, we plan to further investigate the safety and utility of LLLT for acute TBI., The original document contains color images.

We present an application of absorption spectroscopy to directly measure temperature and concentration histories of water vapor within the expansion of a high explosive detonation. While the approach of absorption spectroscopy is well established, the combination of a fast near-infrared array, broadband light source, and rigid gauge allow the first application of time-resolved absorption measurements in an explosive environment. The instrument is demonstrated using pentaerythritol tetranitrate with a sampling rate of 20 kHz for 20 ms following detonation. Absorption by water vapor is measured between 1335 and 1380 nm. Water temperatures are determined by fitting experimental transmission spectra to a simulated database. Water mole fractions are deduced following the temperature assignment. The sources of uncertainty and their impact on the results are discussed. These measurements will aid the development of chemical-specific reaction models and the predictive capability in technical fields including combustion and detonation science., Published in Measurement Science and Technology, v22 p1-10, 15 Mar 2011.

Dental caries is a widespread disease that affects many children. Through a concerted effort by the parents, dentist, and child, the decay process can be arrested/reversed by non-surgical means via fluoride therapy, antimicrobial rinses, dietary changes, or low-intensity laser irradiation. However, success of these preventative measures depends to a great extent on the early detection of the decay process. Traditionally, dentists have utilized tactile and visual techniques to detect caries, but unfortunately these methods have a low sensitivity. Conventional radiography (x-rays) is adequate for large, cavitated lesions; however, it does not have sufficient sensitivity for the detection of early, non-cavitated caries, root surface caries, or secondary caries. Moreover, due to the distinct morphology of the primary dentition, including thin enamel, proportionally thinner dentin, and large pulp chambers, the progression of caries is intensified. Therefore, new methods for early caries detection are necessary. Recently, new technology has been approved for the diagnosis of decay, e.g. the DIAGNOdent and QLF, but these devices detect caries in its late stages when surgical intervention is usually necessary. Moreover, these devices do not provide depth-resolved images of the caries and therefore, cannot be used to assess the effectiveness of properly implemented preventative measures. Polarization-sensitive optical coherence tomography (PS-OCT) is a non-invasive imaging technique which utilizes near-infrared (NIR) light to produce depth-resolved images of dental enamel and has the potential to monitor early enamel caries. The scattering of light in the sound enamel and dentin is sufficiently strong in the visible range to obscure light transmission through the tooth. However, in the near-IR at 1310nm, enamel is highly transparent. The tissue contrast with devices utilizing near-IR light arises from changes in tissue scattering as opposed to conventional radiography, which

Dental caries is a widespread disease that affects many children. Through a concerted effort by the parents, dentist, and child, the decay process can be arrested/reversed by non-surgical means via fluoride therapy, antimicrobial rinses, dietary changes, or low-intensity laser irradiation. However, success of these preventative measures depends to a great extent on the early detection of the decay process. Traditionally, dentists have utilized tactile and visual techniques to detect caries, but unfortunately these methods have a low sensitivity. Conventional radiography (x-rays) is adequate for large, cavitated lesions; however, it does not have sufficient sensitivity for the detection of early, non-cavitated caries, root surface caries, or secondary caries. Moreover, due to the distinct morphology of the primary dentition, including thin enamel, proportionally thinner dentin, and large pulp chambers, the progression of caries is intensified. Therefore, new methods for early caries detection are necessary. Recently, new technology has been approved for the diagnosis of decay, e.g. the DIAGNOdent and QLF, but these devices detect caries in its late stages when surgical intervention is usually necessary. Moreover, these devices do not provide depth-resolved images of the caries and therefore, cannot be used to assess the effectiveness of properly implemented preventative measures. Polarization-sensitive optical coherence tomography (PS-OCT) is a non-invasive imaging technique which utilizes near-infrared (NIR) light to produce depth-resolved images of dental enamel and has the potential to monitor early enamel caries. The scattering of light in the sound enamel and dentin is sufficiently strong in the visible range to obscure light transmission through the tooth. However, in the near-IR at 1310nm, enamel is highly transparent. The tissue contrast with devices utilizing near-IR light arises from changes in tissue scattering as opposed to conventional radiography, which