Fabrication of photothermally active poly(vinyl alcohol) films with gold nanostars for antibacterial applications.

The unique photothermal properties of non-spherical gold nanoparticles under near-infrared (NIR) irradiation find broad application in nanotechnology and nanomedicine. The combination of their plasmonic features with widely used biocompatible poly(vinyl alcohol) (PVA) films can lead to novel hybrid polymeric materials with tunable photothermal properties and a wide range of applications. In this study, thin PVA films containing highly photothermally efficient gold nanostars (GNSs) were fabricated and their properties were studied. The resulting films displayed good mechanical properties and a pronounced photothermal effect under NIR irradiation. The local photothermal effect triggered by NIR irradiation of the PVA-GNS films is highly efficient at killing bacteria, therefore providing an opportunity to develop new types of protective antibacterial films and coatings

Nanocomposite sprayed films with photo-thermal properties for remote bacteria eradication

Currently there is a strong demand for novel protective materials with effcient antibacterial properties. Nanocomposite materials loaded with photo-thermally active nanoparticles can offer promising opportunities due to the local increase of temperature upon near-infrared (NIR) light exposure capable of eradicating bacteria. In this work, we fabricated antibacterial films obtained by spraying on glass slides aqueous solutions of polymers, containing highly photo-thermally active gold nanostars (GNS) or Prussian Blue (PB) nanoparticles. Under NIR light irradiation with low intensities (0.35W/cm2) these films demonstrated a pronounced photo-thermal effect: 06Tmax up to 26.4 ffC for the GNS-containing films and 06Tmax up to 45.8 ffC for the PB-containing films. In the latter case, such a local temperature increase demonstrated a remarkable effect on a Gram-negative strain (P. aeruginosa) killing (84% of dead bacteria), and a promising effect on a Gram-positive strain (S. aureus) eradication (69% of dead bacteria). The fabricated films are promising prototypes for further development of lightweight surfaces with effcient antibacterial action that can be remotely activated on demand

Self-assembled monolayers of copper sulfide nanoparticles on glass as antibacterial coatings

We developed an easy and reproducible synthetic method to graft a monolayer of copper sulfide nanoparticles (CuS NP) on glass and exploited their particular antibacterial features. Samples were fully characterized showing a good stability, a neat photo-thermal effect when irradiated in the Near InfraRed (NIR) region (in the so called \u201cbiological window\u201d), and the ability to release controlled quantities of copper in water. The desired antibacterial activity is thus based on two different mechanisms: (i) slow and sustained copper release from CuS NP-glass samples, (ii) local temperature increase caused by a photo-thermal effect under NIR laser irradiation of CuS NP\u2013glass samples. This behavior allows promising in vivo applications to be foreseen, ensuring a \u201cstatic\u201d antibacterial protection tailored to fight bacterial adhesion in the critical timescale of possible infection and biofilm formation. This can be reinforced, when needed, by a photo-thermal action switchable on demand by an NIR light

An innovative method of interosseous lumbar spine stabilization surgery using the dynamic implant in a professional athlete as a way to return to competitive activity as quickly as possible

Objective: surgical intervention for spinal pathologies in professional athletes represents a pertinent topic in contemporary sports medicine and neurosurgery, given the extended rehabilitation period and potential decline in competitive activity following spinal surgeries. In this clinical case we describe an innovative technique for stabilizing the lumbar spine in an elite adult professional athlete which enables rapid return to regular competitive activities without restrictions.Materials and methods: a clinical case involving the surgical treatment of lumbar spine instability with compression of neural structures caused by an intervertebral disc herniation is presented. An innovative method for spinal stabilization employing an interbody dynamic implant is outlined.Results: the implementation of this spinal stabilization method allowed an adult professional elite futsal player to resume active physical sport-specific activities without any limitations just three weeks post-surgery.Conclusion: this clinical observation illustrates that spinal fixation using this novel and original method ensures the stability of the operated segment during physical exertion of any intensity

Photothermally Active Inorganic Nanoparticles: from Colloidal Solutions to Photothermally Active Printed Surfaces and Polymeric Nanocomposite Materials

Nanoparticles with absorption in Near-Infrared (NIR) region and subsequent efficient release of heat, are receiving great attention due to wide opportunities of applications in different fields including biotechnology and nanomedicine. However, the colloidal solutions of such nanoparticles may have limitations in effective application connected with long-term stability of nanoparticle solutions and possible re-usability. Therefore, this minireview focuses on the state-of-the art of research and application of photothermally active nanoparticles to engineer remotely activated materials with controllable photothermal properties: printed surfaces and polymeric nanocomposite materials. We highlight in this minireview different types of photothermally active nanoparticles (e.g. non-spherical gold nanoparticles, copper sulfide nanoparticles) that already have been applied for fabrication of printed patterns and polymeric nanocomposites, the properties of the resulting materials and further application opportunitie

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

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

Novel photo-thermally active polyvinyl alcohol-Prussian blue nanoparticles hydrogel films capable of eradicating bacteria and mitigating biofilms

Antibacterial treatment is an essential issue in many diverse fields, from medical device treatments (for example prostheses coating) to food preservation. However, there is a need of novel and light-weight materials with high antibacterial efficiency (preferably due to the physical activation). Utilization of photo-thermally active nanoparticles can lead to novel and re-usable materials that can be remotely activated on-demand to thermally eradicate bacteria and mitigate biofilm formation, therefore meeting the above challenge. In this study polyvinyl alcohol (PVA) hydrogel films containing non-toxic and highly photo-thermally active Prussian blue (PB) nanoparticles were fabricated. The confocal microscopy studies indicated a uniform nanoparticle distribution and a low degree of aggregation. Upon near-infrared (NIR; 700 and 800 nm) light irradiation of PVA-PB films, the local temperature increases rapidly and reaches a plateau (up to \u394T  45 78 \ub0C), within  486-10 s under relatively low laser intensities, I  45 0.3 W cm-2. The high and localized increase of temperature on the fabricated films resulted in an efficient antibacterial effect on Pseudomonas aeruginosa (P. aeruginosa) bacteria. In addition, the localized photo-thermal effect was also sufficient to substantially mitigate biofilms growth

Photo-activated raster scanning thermal imaging at sub-diffraction resolution

Active thermal imaging is a valuable tool for the nondestructive characterization of the morphological properties and the functional state of biological tissues and synthetic materials. However, state-of-the-art techniques do not typically combine the required high spatial resolution over extended fields of view with the quantification of temperature variations. Here, we demonstrate quantitative far-infrared photo-thermal imaging at sub-diffraction resolution over millimeter-sized fields of view. Our approach combines the sample absorption of modulated raster-scanned laser light with the automated localization of the laser-induced temperature variations imaged by a thermal camera. With temperature increments ∼0.5–5 °C, we achieve a six-time gain with respect to our 350-μm diffraction-limited resolution with proof-of-principle experiments on synthetic samples. We finally demonstrate the biological relevance of sub-diffraction thermal imaging by retrieving temperature-based super-resolution maps of the distribution of Prussian blue nanocubes across explanted murine skin biopsies