Effective Distribution of Gold Nanorods in Ordered Thick Mesoporous Silica: A Choice of Noninvasive Theranostics

Surface Modification of Gold Nanorods: Multifunctional Strategies and Application Prospects

Gold nanorods (AuNRs), as an important type of gold nanomaterials, have attracted much attention in the nano field. Compared with gold nanoparticls, AuNRs have broader application potential due to their tunable localized surface plasmon resonance properties and anisotropic shapes. Yet, conventional synthesis methods using surfactants have limited the use of AuNRs in a variety of fields such as biomedical applications, plasma-enhanced fluorescence, optics and optoelectronic devices. To solve this problem and improve the stability and biocompatibility of AuNRs, researchers in recent years have used surface modification and functionalization to modify AuNRs, among which the introduction of organic ligands to prepare organic/gold hybrid nanorods has become an effective strategy. Organic materials have better toughness and easy processing, and by introducing organic ligands into the surface of AuNRs, the molecular-level composite of organic and inorganic materials can be realized, thus obtaining hybrid nanorods with excellent properties. This paper reviews the research progress of hybrid nanocomposites, and introducing the synthesis methods of AuNRs and the development of surface ligand modification, then summarises the applications of a wide variety of ligands. Also, the advantages and disadvantages of different ligands and their roles in further self-assembly processes are discussed.

Stimuli Responsive Molecular Exchange of Structure Directing Agents on Gold Nanobipyramids: Cancer Cell Detection and Synergistic Therapeutics

Surface-engineered gold nanoparticles have been considered as versatile systems for theranostics applications. Moreover, surface covering or stabilizing agents on gold nanoparticles especially gold nanobipyramids (AuNBPs) provides an extra space for cargo molecules entrapment. However, it is not well studied yet and also the preparation of AuNBPs still remains dependent largely on cetyltrimethylammonium bromide (CTAB), a cytotoxic surfactant. Therefore, the direct use of CTAB stabilized nanoparticles is not recommended for cancer theranostics applications. Herein, we address an approach of dodecyl ethyl dimethylammonium bromide (DMAB) as biocompatible structure directing agent for AuNBPs, which also accommodate anticancer drug doxorubicin (45%), an additional chemotherapeutics agent. Upon near-infrared light (NIR, 808 nm) exposure, engineered AuNBPs exhibit (i) better phototransduction (51 °C) due to NIR absorption ability (650-900 nm), (ii) photo triggered drug release (more than 80%), and (iii) synergistic chemophototherapy for breast cancer cells. Drug release response has been evaluated in tumor microenvironment conditions (84% in acidic pH and 80% at high GSH) due to protonation and high affinity of thiol binding with AuNBPs followed by DMAB replacement. Intracellular glutathione (GSH, 5-7.5 mM) replaces DMAB from AuNBPs, which cause easy aggregation of nanoparticles as corroborated by colorimetric shifts, suggesting their utilization as a molecular sensing probe of early stage cancer biomarkers. Our optimized recipe yield is monodisperse DMAB-AuNBPs with ∼90% purity even at large scales (500 mL volume per batch). DMAB-AuNBPs show better cell viability (more than 90%) across all concentrations (5-500 ug/mL) when directly compared to CTAB-AuNBPs (less than 10%). Our findings show the potential of DMAB-AuNBPs for early stage cancer detection and theranostics applications.

Propolis in the management of cardiovascular disease

BACKGROUND

Propolis is a resinous compound that is obtained from honey bees. It consists of numerous chemical constituents that impart different therapeutic action. The heart is the core of the body and cardiovascular disease (CVD) is a burden for the human being. This article emphasizes how propolis is fruitful in the management of various CVDs.

SCOPE AND APPROACH

This review focuses on how various constituents of the propolis (such as terpenes, flavonoids, phenolics, etc.) impart cardio protective actions.

KEY FINDING AND CONCLUSION

With the support of various clinical trials and research outcomes, it was concluded that propolis owns niche cardio protective properties that can be a boon for various cardiac problems (both in preventive and therapeutic action) such as atherosclerosis, excessive angiogenesis, hypertension, and many more.