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In this article, we describe how nanoparticles work in photothermally triggered drug delivery, starting with a description of the plasmon resonance and the photothermal effect, and how this is used to release a drug. Then, we describe the four major functionalization strategies and each of their different applications. Finally, we discuss the biodistribution and toxicity of these systems and the necessary requirements for the use of gold nanoparticles for spatially and temporally controlling drug release through the photothermal effect.

Lab‐on‐a‐particle: Fluorescent, plasmonic, and magnetic SiO2*‐Au‐γ‐Fe2O3 nanostructures were assembled under continuous flow using two microfluidic devices (μR1 and μR2) connected in series. After assembling the SiO2*‐Au nanostructures by electrostatic interactions, γ‐Fe2O3 nanoparticles were attached to the structures (see picture).

One among other remarkable methods to produce multifunctional assemblies with different spatial organizations is the use of liquid–liquid (L–L) interfaces. Herein, a droplet microfluidic-based method is reported as a strategy for the assembly of asymmetrical inorganic nanohybrid structures. As a proof of concept and motivated by their wide applications in different fields, we studied the assembly of two building nanoblocks, which are fluorescent silica (160 nm diameter) and gold nanoparticles (15 nm diameter). In this strategy, droplets of an aqueous solution of citrated gold nanoparticles are generated in a continuous flow of amine functionalized fluorescent silica nanoparticles dispersed in cyclohexane using the microdevice. The electrostatic attraction between the two nanoparticles confined at the water/cyclohexane interface to form a Pickering emulsion allowed their assembly. We show that Janus nanohybrids can only be observed when the residence time in the microdevice was less than 30 min, thus avoiding the formation of solid shells for longer residence times. Transmission and scanning electron microscopies, optical microscopies, and UV–vis spectroscopy were used to characterize the resulting assemblies. The results were compared to experiments in bulk which showed that microfluidics offers a higher control over the assembly and reduces the time for their elaboration. Moreover, an analytical model based on transport of nanoparticles and their adsorption onto interfaces is used to rationalize our observations. Both flow recirculation inside and outside the droplets in the microchannel and the confinement effect seem to be relevant for the enhanced nanoparticle transport to the interfaces

Copper oxide nanoparticles (CuO NPs) were synthesized in air by reducing copper (II) sulfate pentahydrate salt (CuSO4·5H2O) in the presence of sodium borohydride. The reaction was stabilized with Hexadecyltrimethylammonium bromide (CTAB) in a basic medium and using ultrasound waves. Different molar ratios of CTAB:Cu2+ and NaBH4:Cu2+ were explored, to optimize the synthesis conditions, and to study the stability, size, and Zeta potential of the colloidal suspension. Optimum conditions to generate spherical, stable, and monodispersed nanoparticles with hydrodynamic diameters of 36 ± 1.3 nm were obtained, using 16 mM CTAB and 2 M NaBH4 (molar ratios Cu2+:CTAB:NaBH4 of 1:6:10). X-ray diffraction (XRD) was implemented, and a monoclinic CuO crystal system was formed. This demonstrated a monoclinic crystal system corresponding to CuO. The diffraction peaks were identified and confirmed according to their selected area electron diffraction (SAED) patterns.

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Pure decahedral anatase TiO(2) particles with high content of reactive {001} facets were obtained from titanium(IV) tetrachloride (TiCl(4)) using a microemulsions droplet system at specific conditions as chemical microreactor. The product was systematically characterized by X-ray diffraction, field-emission scanning and transmission electron microscopy (FE-SEM, TEM), N(2) adsorption-desorption isotherms, FT-IR and UV-vis spectroscopy, and photoluminescence studies. The obtained cuboids around 90 nm in size have a uniform and dense surface morphology with a BET specific surface area of 11.91 m(2) g(-1) and a band gap energy (3.18 eV) slightly inferior to the anatase dominated by the less-reactive {101} surface (3.20 eV). The presence of reactive facets on titania anatase favors the biomimetic growth of amorphous tricalcium phosphate after the first day of immersion in simulated human plasma. The results presented here can facilitate and improve the integration of anchored implants and enhance the biological responses to the soft tissues.