In the realm of advanced materials, a groundbreaking study led by Katerina Polakova from the Regional Centre of Advanced Technologies and Materials at Palacký University Olomouc, Czech Republic, has unveiled the potential of titanium nitride (TiN) nanoparticles in revolutionizing photothermal therapy (PTT) and photoacoustic imaging (PAI). The research, published in Applied Surface Science Advances, delves into the morphology-dependent near-infrared photothermal activity of TiN nanobars and nanospheres, opening new avenues for anticancer and antibacterial therapies.
TiN nanoparticles have long been recognized for their superior absorption cross-section and photostability, making them a promising alternative to conventional photosensitizers. However, the impact of their morphology on PTT efficiency has remained largely unexplored until now. Polakova and her team addressed this gap by synthesizing TiN nanocrystals in two distinct shapes—nanobars and nanospheres—through a unique pseudomorphic conversion process. This involved nitriding TiO2 nanowires and nanospheres at 800 °C, resulting in materials with broad optical absorption capabilities spanning the entire solar spectrum and biological window, including the NIR-I (750 – 1000 nm) and NIR-II (1000 – 1350 nm) ranges.
The study revealed that the morphology of TiN nanoparticles significantly influences their photothermal activity. When exposed to low-power NIR LED irradiation at 940 nm, TiN nanobars demonstrated superior efficiency in killing cancer HeLa cells compared to nanospheres. Conversely, TiN nanospheres exhibited higher antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria strains. “The morphology-dependent PTT bioactivity of TiN nanoparticles opens up exciting possibilities for targeted therapies,” Polakova explained. “By tailoring the shape of these nanoparticles, we can enhance their effectiveness in specific medical applications, whether it’s cancer treatment or combating bacterial infections.”
The implications of this research extend beyond medical applications. The unique properties of TiN nanoparticles, including their cost-effectiveness and biocompatibility, make them highly attractive for various industrial sectors, particularly in energy. For instance, the enhanced photothermal activity of TiN could lead to more efficient solar energy conversion systems, reducing the reliance on traditional energy sources. Additionally, the broad optical absorption capabilities of TiN nanoparticles could be harnessed to develop advanced sensors and imaging technologies, further driving innovation in the energy sector.
The study also confirmed the acute and long-term in vitro biocompatibility of TiN nanoparticles, as well as their in vivo biodistribution, showing an enhanced permeability and retention (EPR) effect. This was validated through photoacoustic imaging in tumor-bearing mice, highlighting the potential of TiN nanoparticles in theranostic applications. “The ability to monitor the biodistribution of TiN nanoparticles in vivo using PA imaging is a significant step forward,” Polakova noted. “It allows us to track the nanoparticles’ behavior within the body, ensuring their safe and effective use in medical treatments.”
As the field of nanomaterials continues to evolve, the findings from Polakova’s research could pave the way for future developments in PTT and PAI technologies. By understanding and leveraging the morphology-dependent properties of TiN nanoparticles, researchers and industry professionals can unlock new possibilities for targeted therapies, energy conversion, and advanced imaging techniques. The journey towards more effective and efficient medical treatments and energy solutions is well underway, and TiN nanoparticles are poised to play a pivotal role in this exciting future.
