Synthesis and characterization of polystyrene embolization particles doped with tantalum oxide nanoparticles for X-ray contrast

Abstract

Radiopaque and fluorescent embolic particles have been synthesized and characterised to match the size of vasculature found in tumours to ensure effective occlusion of the vessels. A literature search showed that the majority of vessels surrounding a tumour were less than 50 µm and therefore polydispersed polystyrene particles with a peak size of 50 µm have been synthesised. The embolic particles contain 5-8 nm amorphous tantalum oxide nanoparticles which provide X-ray contrast. Embolic particles containing up to 9.4 wt% tantalum oxide were prepared and showed significant contrast compared to the undoped polystyrene particles. The X-ray contrast of the embolic particles was shown to be linear (R(2) = 0.9) with respect to the concentration of incorporated tantalum nanoparticles. A model was developed which showed that seventy-five 50 µm embolic particles containing 10% tantalum oxide could provide the same contrast as 5 cm of bone. Therefore, the synthesized particles would provide sufficient X-ray contrast to enable visualisation within a tumour.

Additively Manufactured Tantalum Implants for Repairing Bone Defects: A Systematic Review

“…Due to high atomic weight and high X-ray absorption of tantalum, it is difficult to obtain perfect imaging results that demonstrate the osteogenic activity and bone ingrowth of am-Ta implants in vivo with standard imaging evaluation techniques. 92 We should acknowledge the fact that clinical application of am-Ta implants for bone repair is still in its infancy. The reported clinical results had a very small sample size, and the follow-up period was also short.…”

Bench-to-bedside development of multifunctional flexible embolic agents

“…There are two major approaches: a) encapsulation and b) in situ generation. For most metal nanoparticles or metal oxide particles that are difficult to synthesize (such as Ta (Figure 6 A, ii) 93 and TaO x (Figure 6 A, iii) 103 nanoparticles), they can be encapsulated into the embolic matrix. For some nanoparticles that can be synthesized by precipitation or redox reactions (such as BaSO 4 (Figure 6 A, iv) 88 , 112 , Bi 2 S 3 124 , Au (Figure 6 A, ii) 125 ), they can be in situ generated within the embolic structure.…”

Evaluation of X‐ray tomography contrast agents: A review of production, protocols, and biological applications

“…MRI investigations reveal weighted contrast enhancement effect in liver. Further studies about encapsulating tantalum oxide nanoparticles into polypyrole nanoparticles for CT/PAI (photoacoustic imaging) and cancer therapy (Jin et al, ) and polystyrene embolization particles doped with tantalum oxide nanoparticles as CT contrast agents (Morrison, Thompson, Bird, & Hill, ) were reported. The 7‐nm TaO x nanoparticles were produced and encapsulated with PPy using chemical oxidation polymerization with total size of 45 nm by Jin et al ().…”