Hollow silica and silica-boron nano/microparticles for contrast-enhanced ultrasound to detect small tumors

Abstract

Diagnosing tumors at an early stage when they are easily curable and may not require systemic chemotherapy remains a challenge to clinicians. In order to improve early cancer detection, gas filled hollow boron-doped silica particles have been developed, which can be used for ultrasound-guided breast conservation therapy. The particles are synthesized using a polystyrene template and subsequently calcinated to create hollow, rigid nanoporous microspheres. The microshells are filled with perfluoropentane vapor. Studies were performed in phantoms to optimize particle concentration, injection dose, and the ultrasound settings such as pulse frequency and mechanical index. In vitro studies have shown that these particles can be continuously imaged by US up to 48 min and their signal lifetime persisted for 5 days. These particles could potentially be given by intravenous injection and, in conjunction with contrast-enhanced ultrasound, be utilized as a screening tool to detect smaller breast cancers before they are detectible by traditional mammography.

Synthesis and surface functionalization of silica nanoparticles for nanomedicine

“…Silica nanoparticles have been developed that can enhance image contrast with existing ultrasound technologies by incorporating perfluorocarbons within the particles; however, solid and hollow silica particles have also been shown to be detectable even by non-contrast imaging modalities [61–67]. Lui et al showed that systemically administering commercial 100 nm solid silica nanoparticles into mice could generate a detectable ultrasound response [68].…”

“…It has been shown that by filling hollow silica nanoparticles with perfluoropentane gas, silica nanoparticles can exhibit substantial contrast under ultrasound imaging [61–63]. The use of hollow silica particles has been explored for tumor detection and imaging with ultrasound.…”

“…Red arrows in all images point to the tumor, the green arrows are the backbone of the mouse, and the blue arrows point to the bottom of the mouse [61]: (A) post mortem examination of mouse reveals large white IGROV-1 tumor mass in the peritoneum. (B) Contrast pulse sequencing (CPS) imaging of the mouse tumor, some particle dependent signal can be seen in the tumor mass.…”

Self-assembled targeting of cancer cells by iron(iii)-doped, silica nanoparticles

“…Silica and iron(III) doped nanoshells have shown promise for in vitro and in vivo ultrasound imaging agents. 76, 80-83 A self-targeting property would potentially broaden their use to drug delivery and tumor localization.…”

Inhibitory Effects of Silica Nanoparticles Loaded with Hematoporphyrin on Breast Cancer Cell Line

“…Nanomaterials can damage cell membranes and DNA and lead to cell death through reactive oxygen species (ROS) production; thus, they can destroy cancer cells (1,3). Mesoporous silica nanoparticles (MSN) known as inorganic nanoparticles (4) are non-metal (5), solid, and highly porous oxides (6). These nanoparticles are used broadly in engineering, industry, biomedical applications, cosmetics, and FDA-approved food additives (7).…”