Development of drug loaded nanoparticles for tumor targeting. Part 1: synthesis, characterization, and biological evaluation in 2D cell cultures

Abstract

Nanoparticles (NPs) are being extensively studied as carriers for drug delivery, but they often have limited penetration inside tumor. We envision that by targeting an endocytic receptor on cell surface, the uptake of NPs can be significantly enhanced through receptor mediated endocytosis. In addition, if the receptor is recycled to cell surface, the NP cargo can be transported out of the cells, which are then taken up by neighboring cells thus enhancing solid tumor penetration. To validate our hypothesis, in the first of two articles, we report the synthesis of doxorubicin (DOX)-loaded, hyaluronan (HA) coated silica nanoparticles (SNP) containing a highly fluorescent core to target CD44, a receptor expressed on cancer cell surface. HA was conjugated onto amine-functionalized SNPs prepared through an oil/water microemulsion method. The immobilization of the cytotoxic drug DOX was achieved through an acid sensitive hydrazone linkage. The NPs were fully characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential measurements, thermal gravimetric analysis (TGA), UV-vis absorbance, and nuclear magnetic resonance (NMR). Initial biological evaluation experiments demonstrated that compared to ligand-free SNPs, the uptake of HA-SNP by the CD44-expressing SKOV-3 ovarian cancer cells was significantly enhanced when evaluated in the 2D monolayer cell culture. Mechanistic studies suggested that cellular uptake of HA-SNP was mainly through CD44 mediated endocytosis. HA-SNPs with DOX immobilized were endocytosed efficiently by the SKOV-3 cells as well. The enhanced tumor penetration and drug delivery properties of HA-SNP will be evaluated in 3D tumor models in the subsequent paper.

Design of thiol- and light-sensitive degradable hydrogels using Michael-type addition reactions

“…Nanobeads were chosen here for proof of concept where similarly sized particles loaded or decorated with small molecular drugs, proteins, or siRNA can be encapsulated within these hydrogels for localized release for specific applications of interest. 69, 70 Note, a more continuous release profile upon bulk degradation by thiol exchange or hydrolysis would be expected for biologics (e.g., antibodies and other therapeutic proteins) directly encapsulated within these types of gels; protein release will be driven by diffusion as the mesh size of the hydrogel increases commensurate with degradation, as observed in our earlier work with dually degradable hydrogels. 37 Overall, these results support the hypothesis that the release of cargo can be tuned by controlling the degradation rate and, in principle, such a strategy could be employed for spatiotemporal control over release of cargo molecules in biological systems.…”

Selective anticancer activity of hydroxyapatite/chitosan-poly(d,l)-lactide-co-glycolide particles loaded with an androstane-based cancer inhibitor

“…HAp nanoparticles can slow down the growth of various cancer cells, particularly human glioma cells [16]. Organ-targeting or tumor-targeting via drug-loaded nanoparticles demonstrated their ability to act on specific receptors [17]. The targeting of receptors by HAp nanocrystals was proposed as the basis for the utilization of HAp doped with rare earth elements for noninvasive medical imaging at the molecular level [18].…”

Assessing the in Vivo Efficacy of Doxorubicin Loaded Hyaluronan Nanoparticles

“…40 We recently reported that conjugating the anticancer drug doxorubicin (DOX) on the surface of nanoparticles (Figure 1) rendered the DOX-resistant NCI-ADR-RES ovarian cancer cells more sensitive to drug treatment most likely through modulation of the intracellular distribution of drug. 27 The interaction between the hyaluronan (HA) coating on the nanoparticles and the CD44 receptor overexpressed on the external cell membranes of SKOV-3 epithelial ovarian cancer cells facilitated the enhanced uptake of the nanoparticles by cells in 2D cell cultures, 41 and mediated deeper penetration of the nanoparticles in 3D SKOV-3 cancer spheroids through receptor mediated transcytosis. 42 In this manuscript, we investigate the efficacy of DOX conjugated onto HA-SPIONs in vivo in subcutaneous (S.C.) and intraperitoneal (I.P.)…”