Atomic Force Microscopy Probing of Receptor–Nanoparticle Interactions for Riboflavin Receptor Targeted Gold–Dendrimer Nanocomposites

Abstract

Riboflavin receptors are overexpressed in malignant cells from certain human breast and prostate cancers, and they constitute a group of potential surface markers important for cancer targeted delivery of therapeutic agents and imaging molecules. Here we report on the fabrication and atomic force microscopy (AFM) characterization of a core–shell nanocomposite consisting of a gold nanoparticle (AuNP) coated with riboflavin receptor-targeting poly(amido amine) dendrimer. We designed this nanocomposite for potential applications such as a cancer targeted imaging material based on its surface plasmon resonance properties conferred by AuNP. We employed AFM as a technique for probing the binding interaction between the nanocomposite and riboflavin binding protein (RfBP) in solution. AFM enabled precise measurement of the AuNP height distribution before (13.5 nm) and after chemisorption of riboflavin-conjugated dendrimer (AuNP–dendrimer; 20.5 nm). Binding of RfBP to the AuNP–dendrimer caused a height increase to 26.7 nm, which decreased to 22.8 nm when coincubated with riboflavin as a competitive ligand, supporting interaction of AuNP–dendrimer and its target protein. In summary, physical determination of size distribution by AFM imaging can serve as a quantitative approach to monitor and characterize the nanoscale interaction between a dendrimer-covered AuNP and target protein molecules in vitro.

Riboflavin-Targeted Drug Delivery

“…Furthermore, the RF-targeted dendrimer conjugate (N-10 position) was used to coat gold nanoparticles (AuNP) [76]. The AuNP were prepared by the gold (III) reduction method and had a hydrodynamic size of 30 nm according to dynamic light scattering (DLS), while atomic force microscopy (AFM) showed a 13.5 nm core diameter.…”

“…The dendrimer conjugates were attached to the AuNP via gold-sulfur chemisorption and had a size of 20.5 nm measured by AFM. The uptake of AuNP-PAMAM-RF was tested in KB cells [76]. According to surface plasmon resonance (SPR) and luminescence of AuNP, the RF-targeted nanocomposite showed higher internalization into cells than the control.…”

Adsorption of Organophosphate Pesticide Dimethoate on Gold Nanospheres and Nanorods

“…Freshly cleaved mica was modified with a 100 L deposit of 0.01% 3-(aminopropyl)triethoxysilane (APTES) solution. After a 20 min incubation period, the mica surface was rinsed six times with 1 mL aliquots of water and dried with compressed nitrogen [25]. A drop of 10 L suspension of AuNPs without and with dimethoate was deposited on mica surface and incubated for 30 min, followed by repeated washing with deionized water to remove any unbound materials and dried in air for AFM measurements [26].…”

Riboflavin immobilized Fe 3 O 4 magnetic nanoparticles carried with n -butylidenephthalide as targeting-based anticancer agents

“…Previous reports [32][33][34][35][36][37][38][39][40] showed that BP can induce cell death of certain cancer cells through apoptosis. When cancer cells respond to apoptotic stimuli, the nerve growth factor IB, that is, Nur77, translocates from the nucleus to the mitochondria, where it binds to B-cell lymphoma 2.…”

“…Angelica sinensis (Danggui), a common Chinese medicinal herb, has been used to promote blood circulation [29] to treat female menstrual disorders [30] and menopausal symptoms [31]. n-Butylidenephthalide (BP) is one of the active ingredients of A. sinensis with potential in treating multiforme [32][33][34][35], breast cancer [32], prostate cancer [36,37], oral squamous cell carcinoma [38], lung cancer [39] and hepatoma [40].…”