Imaging of drug loading distributions in individual microspheres of calcium silicate hydrate--an X-ray spectromicroscopy study

Tracking the interaction of drug molecules with individual mesoporous amorphous calcium phosphate/ATP nanocomposites - an X-ray spectromicroscopy study

Adenosine triphosphate (ATP) biomolecules play critial roles in the biomineralization process during the formation of amorphous calcium phosphate composites (ACPC), and ACPC is an important drug carrier due to its significant advantages of biocompatibility and biodegradability. Hence, studying the behavior of ACPC nanodrug carriers is crucial to investigate the structural regulation of biomimetic minerals and calcium phosphate (CaP)-based drug delivery systems. However, it is difficult to probe these interactions using traditional characterization methods. In this paper, XANES analysis together with STXM successfully provided a method to reveal the interaction of ATP and drug molecules with individual mesoporous ACPC. We found that the adenosine and phosphate groups of ATP biomolecules coordinated with Ca²⁺ and played critical roles in the formation of ACPC; drug molecules with the -COOH groups were linked to Ca²⁺via carboxylic acid groups primarily by electrostatic interactions, and the N-containing ring structures within the drug molecules also coordinated with Ca²⁺.

Nanostructured Calcium-based Biomaterials and their Application in Drug Delivery

In the past several decades, various types of nanostructured biomaterials have been developed. These nanostructured biomaterials have promising applications in biomedical fields such as bone repair, tissue engineering, drug delivery, gene delivery, antibacterial agents, and bioimaging. Nanostructured biomaterials with high biocompatibility, including calcium phosphate, hydroxyapatite, and calcium silicate, are ideal candidates for drug delivery. This review article is not intended to offer a comprehensive review of the nanostructured biomaterials and their application in drug delivery but rather presents a brief summary of the recent progress in this field. Our recent endeavors in the research of nanostructured biomaterials for drug delivery are also summarized. Special attention is paid to the synthesis and properties of nanostructured biomaterials and their application in drug delivery with the use of typical examples. Finally, we discuss the problems and future perspectives of nanostructured biomaterials in the drug delivery field.

Calcium-based biomaterials for diagnosis, treatment, and theranostics

Calcium-based biomaterials with good biosafety and bio-absorbability are promising for biomedical applications such as diagnosis, treatment, and theranostics.

Scanning transmission X-ray microscopy studies of chromium hydroxide hollow spheres and nanoparticles formed by gamma radiation

Amorphous chromium-containing solid nanoparticles and hollow spheres were formed as the intermediate product during the synthesis of Cr2O3 by gamma radiolysis of dichromate solution. Scanning transmission X-ray microscopy (STXM) is applied to investigate the electronic structure and chemical composition of this intermediate product (solid nanoparticles and hollow spheres). The STXM result obtained at O K-edge and Cr L3,2-edge confirms that chromium in the sample exists as Cr3+ and that the solid nanoparticles and hollow spheres are both Cr(OH)3. Combined with other techniques, a mechanism for gamma radiation induced formation of Cr2O3 nanoparticles via Cr(OH)3 intermediates from dissolved dichromate is proposed.

Tracking the transformations of mesoporous microspheres of calcium silicate hydrate at the nanoscale upon ibuprofen release: a XANES and STXM study

XANES and STXM imaging of mesoporous CSH microspheres indicate that amorphous silica provide aggregation site of HAp, and amorphous CaCO₃ was formed during CSH biomineralization.