808 nm NIR Laser-Excited Upconversion Nanoplatform for Combinatory Photodynamic and Chemotherapy with Deep Penetration and Acid Bursting Release Performance

Shortwave Infrared Imaging of a Quantum Dot-Based Magnetic Guidewire Toward Non-Fluoroscopic Peripheral Vascular Interventions

Peripheral vascular interventions (PVIs) offer several benefits to patients with lower extremity arterial diseases, including reduced pain, simpler anesthesia, and shorter recovery time, compared to open surgery. However, to monitor the endovascular tools inside the body, PVIs are conducted under X-ray fluoroscopy, which poses serious long-term health risks to physicians and patients. Shortwave infrared (SWIR) imaging of quantum dots (QDs) has shown great potential in bioimaging due to the non-ionizing penetration of SWIR light through tissues. In this paper, a QD-based magnetic guidewire and its system is introduced that allows X-ray-free detection under SWIR imaging and precise steering via magnetic manipulation. The QD magnetic guidewire contains a flexible silicone tube encapsulating a QD polydimethylsiloxane (PDMS) composite, where HgCdSe/HgS/CdS/CdZnS/ZnS/SiO2 core/multi-shell QDs are dispersed in the PDMS matrix for SWIR imaging upon near-infrared excitation, as well as a permanent magnet for magnetic steering. The SWIR penetration of the QD magnetic guidewire is investigated within an artificial tissue model (1% Intralipid) and explore the potential for non-fluoroscopic PVIs within a vascular phantom model. The QD magnetic guidewire is biocompatible in its entirety, with excellent resistance to photobleaching and chemical alteration, which is a promising sign for its future clinical implementation.

Actively targeted gold-polydopamine (PDA@Au) nanocomplex for sequential drug release and combined synergistic chemo-photothermal therapeutic effects

Multifunctional nanoparticles for treatment in cancer are getting more and more attention recently. In this study, we employed a novel polydopamine (PDA) framework-based gold nanoparticles as a carrier of an antimetabolite drug, 5-Fluorouracil (5-FU). Folic acid (FA) was embellished onto the surface of nanoparticle imparting the nanosystem with remarkable tumor-targeting abilities through its precise binding with FA receptor that is notably overexpressed in breast cancer cells. PDA served as a photothermal treatment (PTT) agent and a gatekeeper to regulate drug release since it is highly pH-sensitive and might lengthen the residency period while simultaneously enhancing water solubility and biological compatibility of nanomaterials. Gold nanoparticles (Au NPs) end up serving as both a drug delivery platform and a source of substantial photothermal effects, culminating in synergistically coupled chemo-photothermal therapy. The PDA@Au@FA nanocomplex, loaded with 5-FU, is biocompatible, features strong NIR absorption and photothermal conversion, and can control drug release in pH/NIR dual response environment. The cell viability in PDA@Au@5-FU-FA group with NIR irradiation in 48 h was only 20.1 ± 2.6%. In addition, apoptosis staining experiments revealed greater cellular uptake of PDA@Au@5-FU-FA by MCF-7 cells. Therefore, PDA@Au@5-FU-FA nanocomplex that we postulated herein may be a potential contender for effective curative treatment for breast cancer.

The Coming of Age of Neodymium: Redefining Its Role in Rare Earth Doped Nanoparticles

Among luminescent nanostructures actively investigated in the last couple of decades, rare earth (RE³⁺) doped nanoparticles (RENPs) are some of the most reported family of materials. The development of RENPs in the biomedical framework is quickly making its transition to the ∼800 nm excitation pathway, beneficial for both in vitro and in vivo applications to eliminate heating and facilitate higher penetration in tissues. Therefore, reports and investigations on RENPs containing the neodymium ion (Nd³⁺) greatly increased in number as the focus on ∼800 nm radiation absorbing Nd³⁺ ion gained traction. In this review, we cover the basics behind the RE³⁺ luminescence, the most successful Nd³⁺-RENP architectures, and highlight application areas. Nd³⁺-RENPs, particularly Nd³⁺-sensitized RENPs, have been scrutinized by considering the division between their upconversion and downshifting emissions. Aside from their distinctive optical properties, significant attention is paid to the diverse applications of Nd³⁺-RENPs, notwithstanding the pitfalls that are still to be addressed. Overall, we aim to provide a comprehensive overview on Nd³⁺-RENPs, discussing their developmental and applicative successes as well as challenges. We also assess future research pathways and foreseeable obstacles ahead, in a field, which we believe will continue witnessing an effervescent progress in the years to come.

Upconversion Nanomaterials in Bioimaging and Biosensor Applications and Their Biological Response

In recent decades, upconversion nanomaterials (UCNMs) have attracted considerable research interest because of their unique optical properties, such as large anti-Stokes shifts, sharp emissions, non-photobleaching, and long lifetime. These unique properties make them ideal candidates for unified applications in biomedical fields, including drug delivery, bioimaging, biosensing, and photodynamic therapy for specific cancers. This review describes the general mechanisms of upconversion, synthesis methods, and potential applications in biology and their biological responses. Additionally, the biological toxicity of UCNMs is explained and summarized with the associated intracellular association mechanisms. Finally, the prospects and future challenges of UCNMs at the clinical level in biological applications are described, along with a summary of opportunity for biological as well as clinical applications of UCNMs.