Fluorescence conjugated nanostructured cobalt-doped hydroxyapatite platform for imaging-guided drug delivery application

Self-calibrated HAp:Tb-EDTA paper-based probe with dual emission ratio fluorescence for binary visual and fluorescent detection of anthrax biomarker

Development of the portable device is significant for sensitive and rapid detection of an anthrax biomarker dipicolinic acid (DPA), existing in the B. anthracis. In this work, a novel HAp:Tb-EDTA paper-based ratiometric fluorescent sensor was obtained by a simple one-pot method for rapid and sensitive DPA detection. With the increased DPA concentration, the luminescence intensity of HAp (hydroxyapatite) remained constant, and thus applied as the stable reference signal, while the luminescence signal of Tb3+-EDTA was significantly enhanced due to the antenna effect. Therefore, the HAp:Tb-EDTA paper-based sensor was endowed with self-calibrated and ratiometric fluorescent detection performance for DPA. The proposed sensor showed excellent detection performance with a detection limit as low as 10.8 nM in the linear range of 0.5-30 μM. After combination with a smartphone, rapid visual and fluorescent detection of DPA was achieved. The proposed sensor was successfully applied to detect DPA from B. subtilis spore real samples, showing the application prospects of the paper-based sensors and opening a new horizon to develop novel paper-based point-of-care testing (POCT) devices.

Nanotechnology for brain tumor imaging and therapy based on π-conjugated materials: state-of-the-art advances and prospects

In contemporary biomedical research, the development of nanotechnology has brought forth numerous possibilities for brain tumor imaging and therapy. Among these, π-conjugated materials have garnered significant attention as a special class of nanomaterials in brain tumor-related studies. With their excellent optical and electronic properties, π-conjugated materials can be tailored in structure and nature to facilitate applications in multimodal imaging, nano-drug delivery, photothermal therapy, and other related fields. This review focuses on presenting the cutting-edge advances and application prospects of π-conjugated materials in brain tumor imaging and therapeutic nanotechnology.

Yb-Gd Codoped Hydroxyapatite as a Potential Contrast Agent for Tumor-Targeted Biomedical Applications

Recently, various nanomaterials based on hydroxyapatite (HAp) have been developed for bioimaging applications. In particular, HAp doped with rare-earth elements has attracted significant attention, owing to its enhanced bioactivity and imaging properties. In this study, the wet precipitation method was used to synthesize HAp codoped with Yb and Gd. The synthesized Ybx-Gdx-HAp nanoparticles (NPs) were characterized via various techniques to analyze the crystal phase, functional groups, thermal characteristics, and particularly, the larger surface area. The IR783 fluorescence dye and a folic acid (FA) receptor were conjugated with the synthesized Ybx-Gdx-HAp NPs to develop an effective imaging contrast agent. The developed FA/IR783/Yb-Gd-HAp nanomaterial exhibited improved contrast, sensitivity, and tumor-specific properties, as demonstrated by using the customized LUX 4.0 fluorescence imaging system. An in vitro cytotoxicity study was performed to verify the biocompatibility of the synthesized NPs using MTT assay and fluorescence staining. Photodynamic therapy (PDT) was also applied to determine the photosensitizer properties of the synthesized Ybx-Gdx-HAp NPs. Further, reactive oxygen species generation was confirmed by Prussian blue decay and a 2',7'-dichlorofluorescin diacetate study. Moreover, MDA-MB-231 breast cancer cells were used to evaluate the efficiency of Ybx-Gdx-HAp NP-supported PDT.

The Effect of Alginate Concentration on Crystallinity, Morphology, and Thermal Stability Properties of Hydroxyapatite/Alginate Composite

Hydroxyapatite (HAp) has been used for various applications such as orthopedics, drug delivery material, and bone tissue engineering. It is well known that HAp has a good biocompatibility and osteoconductivity, so HAp can be used in biomedical applications. Hydroxyapatite can be combined with other materials, in particular polymer, to expand its range of applications. In this study, the polymer that will be used as a support for the HAp composite is alginate (Alg). The HAp/Alg composite has been synthesized by the precipitation method. The XRD results show that the crystal system of HAp was hexagonal. The spheric-like shaped particles can be observed from SEM images, and particle size distribution spread from 400 to 1100 nm. The EDS spectrum exhibited the peak of Ca, C, P, and O elements, indicating that alginate had interacted with hydroxyapatite in the synthesized composite. The as-fabricated composite showed not only good crystallinity but also high thermal resistance. Thermogravimetric-differential thermal analysis (TGA-DTA) revealed that the HAp/Alg composites have a constant weight at 750 °C, so it might be applied in advanced applications such as bioimaging, drug carrier, and other cancer treatments.