An in-vitro investigation of skin tissue soldering using gold nanoshells and diode laser

In Vitro and Ex Planta Gold-Bonded and Gold-Mineralized Tobacco Mosaic Virus

Biotemplated mineralization is a promising and ecofriendly approach to manufacture metal nanoparticles and composites with precise size control. Plant viruses are suitable templates for biomineralization because they are chemically robust and highly scalable through molecular farming. Here, we report a gold-nanoparticle-coated tobacco mosaic virus (TMV) synthesized in a test tube or in plant extracts making use of a TMV displaying a gold-binding peptide (GBP). The methods developed are a step toward engineered living materials, where gold nanowires could be formed in plant tissues for sensing or energy harvest applications.

Near IR-plasmon enhanced guided fluorescence and thermal imaging of tissue subsurface target using ICG-labeled gold nanourchin and protein contrast agent: implication of stability

A dual-function nanocomposite agent (NCA) was prepared for deep tissue fluorescence and thermal imaging. The results showed that a combination of some agents such as gold nanourchins (GNU) and indocyanine green (ICG) can have spectral overlapping and hence some peak broadening. Despite 83% and 92% loss of NCA fluorescence after tissue layers L1 and L2, respectively, there was sufficient signal detected for imaging the target buried under the tissue. No fluorescence was detected after L3. A significant contribution was made by GNU for both the fluorescence signal due to the plasmon-enhanced fluorescence (PEF) effect and the thermal heating because of local surface plasmon resonance (LSPR) due to its sharp tips. In the first case, PEF occurred within the first 40 s then followed by a gradual quenching by 23% in 4 min and 72% in the following 6 min. During the second quenching time, the emission signal was blue shifted by 10 nm. Of the three samples, sample 2 (S2) indicated the highest temperature rise ≈ 60 °C in 50 s; sample 3 (S3) produced the lowest temperature of ≈ 33 °C in 250 s after the first layer, thus showing BSA acting as a heat sink. Both the heating and cooling time are determined by the thermal properties of the material such as conductivity and diffusivity. Finally, despite the advantages of PEF, the photostability and quenching rate of a dye molecule must be considered in a dynamic detection monitoring system to account and compensate for the effect of contrast agent quality variation.

Nanoshell-mediated targeted photothermal therapy of HER2 human breast cancer cells using pulsed and continuous wave lasers: an in vitro study

In this study, we report the apoptosis induction in HER2 overexpressed breast cancer cells using pulsed, continuous wave lasers and polyvinylpyrrolidone (PVP)-stabilized magneto-plasmonic nanoshells (PVP-MPNS) delivered by immunoliposomes. The immunoliposomes containing PVP-MPNS were fabricated and characterized. Heating efficiency of the synthesized nanostructures was calculated. The effect of functionalization on cellular uptake of nanoparticles was assessed using two cell lines of BT-474 and Calu-6. The best uptake result was achieved by functionalized liposome (MPNS-LAb) and BT-474. Also, the interaction of 514 nm argon (Ar) and Nd/YAG second harmonic 532-nm lasers with nanoparticles was investigated based on the temperature rise of the nanoshell suspension and the release value of 5(6)-carboxyfluorescein (CF) from CF/MPNS-loaded liposomes. The temperature increase of the suspensions after ten consecutive pulses of 532 nm and 5 min of irradiation by Ar laser were measured approximately 2 and 12 °C, respectively. The irradiation of CF/MPNS-loaded liposomes by Ar laser for 3 min resulted in 24.3 % release of CF, and in the case of 532 nm laser, the release was laser energy dependent. Furthermore, the comparison of CF release showed a higher efficiency for the Ar laser than by direct heating of nanoshell suspension using circulating water. The percentage of cell apoptosis after irradiation by Ar and 532 nm lasers were 44.6 and 42.6 %, respectively. The obtained results suggest that controlling the NP-laser interaction using optical properties of nanoshells and the laser parameters can be used to develop a new cancer therapy modality via targeted nanoshell and drug delivery.

Simulation and experimental results of optical and thermal modeling of gold nanoshells

This paper proposes a generalized method for optical and thermal modeling of synthesized magneto-optical nanoshells (MNSs) for biomedical applications. Superparamagnetic magnetite nanoparticles with diameter of 9.5 ± 1.4 nm are fabricated using co-precipitation method and subsequently covered by a thin layer of gold to obtain 15.8 ± 3.5 nm MNSs. In this paper, simulations and detailed analysis are carried out for different nanoshell geometry to achieve a maximum heat power. Structural, magnetic and optical properties of MNSs are assessed using vibrating sample magnetometer (VSM), X-ray diffraction (XRD), UV-VIS spectrophotometer, dynamic light scattering (DLS), and transmission electron microscope (TEM). Magnetic saturation of synthesized magnetite nanoparticles are reduced from 46.94 to 11.98 emu/g after coating with gold. The performance of the proposed optical-thermal modeling technique is verified by simulation and experimental results.

Emerging concepts of laser-activated nanoparticles for tissue bonding

We report recent achievements and future perspectives of minimally invasive bonding of biological tissues triggered by laser light. In particular, we review new advancements in the biomedical exploitation of near-infrared absorbing gold nanoparticles as an original solution for the photothermal closure of surgical incisions. Advanced concepts of laser tissue bonding involving the application of hybrid nanocomposites obtained by inclusion of nanochromophores into biopolymer scaffolds are also introduced. The perspectives of tissue bonding are discussed in the following aspects: (1) tissue bonding with highly-stabilized nanochromophores, (2) enhanced tissue bonding with patterned nanocomposites, (3) real-time monitoring of temperature distributions, (4) tracking of tissue regeneration based on the optical resonances of gold nanoparticles.

Enhanced laser tissue soldering using indocyanine green chromophore and gold nanoshells combination

Gold nanoshells (GNs) are new materials that have an optical response dictated by the plasmon resonance. The wavelength at which the resonance occurs depends on the core and shell sizes. The purposes of this study were to use the combination of indocyanine green (ICG) and different concentration of gold nanoshells for skin tissue soldering and also to examine the effect of laser soldering parameters on the properties of repaired skin. Two mixtures of albumin solder and different combinations of ICG and gold nanoshells were prepared. A full thickness incision of 2 × 20 mm(2) was made on the surface and after addition of mixtures it was irradiated by an 810 nm diode laser at different power densities. The changes of tensile strength (σ(t)) due to temperature rise, number of scan (Ns), and scan velocity (Vs) were investigated. The results showed at constant laser power density (I), σ(t) of repaired incisions increases by increasing the concentration of gold nanoshells in solder, Ns, and decreasing Vs. It was demonstrated that laser soldering using combination of ICG + GNs could be practical provided the optothermal properties of the tissue are carefully optimized. Also, the tensile strength of soldered skin is higher than skins that soldered with only ICG or GNs. In our case, this corresponds to σ(t) = 1800 g cm(-2) at I ∼ 47 Wcm(-2), T ∼ 85 [ordinal indicator, masculine]C, Ns = 10, and Vs = 0.3 mms(-1).