Hyaluronate-Thiol Passivation Enhances Gold Nanoparticle Peritumoral Distribution When Administered Intratumorally in Lung Cancer

Hyaluronic acid-functionalized nanomedicines for CD44-receptors-mediated targeted cancer therapy: A review of selective targetability and biodistribution to tumor microenvironment

Cancer is a leading cause of death globally, driven by late diagnoses, aggressive progression, and multidrug resistance (MDR). Advances in nanotechnology are tackling these challenges, paving the way for transformative cancer treatments. Hyaluronic acid (HA)-based nanoparticles (NPs) have emerged as promising platforms due to their biocompatibility, biodegradability, and natural targeting capabilities via CD44 (cluster of differentiation 44) receptors. Functionalizing NPs with HA enhances cellular uptake through CD44, improves pharmacokinetics, tumor localization, and anticancer efficacy while reducing systemic toxicity. This review provides a comprehensive overview of HA-based NPs, highlighting their potential to address limitations in cancer treatment and inspire further innovation. The targeting efficiency of HA-based NPs can be further optimized by integrating passive (e.g., PEGylation), active (e.g., ligand conjugation), and stimuli-responsive mechanisms (e.g., pH, redox, light, enzyme activity, and temperature sensitivity). These NPs also enable therapeutic combinations, such as co-delivery of chemotherapeutics with gene therapies (e.g., siRNA) and integration of photothermal and photodynamic therapies, alongside immune checkpoint inhibitors, amplifying therapeutic synergy. Despite promising preclinical results, challenges such as scalability, stability, long-term safety, ethical and regulatory hurdles, and high costs persist. Nonetheless, HA-based NPs represent a cutting-edge approach, combining biocompatibility, precision targeting, and multimodal functionality to combat cancer effectively, while mitigating side effects.

Preparation, Characterization, and Anticancer Activity Assessment of Chitosan/TPP Nanoparticles Loaded with Echis carinatus Venom

AIMS AND BACKGROUND

Echis carinatus venom is a toxic substance naturally produced by special glands in this snake species. Alongside various toxic properties, this venom has been used for its therapeutic effects, which are applicable in treating various cancers (liver, breast, etc.).

OBJECTIVE

Nanotechnology-based drug delivery systems are suitable for protecting Echis carinatus venom against destruction and unwanted absorption. They can manage its controlled transfer and absorption, significantly reducing side effects.

METHODS

In the present study, chitosan nanoparticles were prepared using the ionotropic gelation method with emulsion cross-linking. The venom's encapsulation efficiency, loading capacity, and release rate were calculated at certain time points. Moreover, the nanoparticles' optimal formulation and cytotoxic effects were determined using the MTT assay.

RESULTS

The optimized nanoparticle formulation increases cell death induction in various cancerous cell lines. Moreover, chitosan nanoparticles loaded with Echis carinatus venom had a significant rate of cytotoxicity against cancer cells.

CONCLUSION

It is proposed that this formulation may act as a suitable candidate for more extensive assessments of cancer treatment using nanotechnology-based drug delivery systems.

Thiol functionalised gold nanoparticles loaded with methotrexate for cancer treatment: From synthesis to in vitro studies on neuroblastoma cell lines

HYPOTHESIS

Colloidal gold nanoparticles (AuNPs) functionalised with hydrophilic thiols can be used as drug delivery probes, thanks to their small size and hydrophilic character. AuNPs possess unique properties for their use in nanomedicine, especially in cancer treatment, as diagnostics and therapeutic tools.

EXPERIMENTS

Thiol functionalised AuNPs were synthesised and loaded with methotrexate (MTX). Spectroscopic and morphostructural characterisations evidenced the stability of the colloids upon interaction with MTX. Solid state (GISAXS, GIWAXS, FESEM, TEM, FTIR-ATR, XPS) and dispersed phase (UV-Vis, DLS, ζ-potential, NMR, SAXS) experiments allowed to understand structure-properties correlations. The nanoconjugate was tested in vitro (MTT assays) against two neuroblastoma cell lines: SNJKP and IMR5 with overexpressed n-Myc.

FINDINGS

Molar drug encapsulation efficiency was optimised to be >70%. A non-covalent interaction between the π system and the carboxylate moiety belonging to MTX and the charged aminic group of one of the thiols was found. The MTX loading slightly decreased the structural order of the system and increased the distance between the AuNPs. Free AuNPs showed no cytotoxicity whereas the AuNPs-MTX nanoconjugate had a more potent effect when compared to free MTX. The active role of AuNPs was evidenced by permeation studies: an improvement on penetration of the drug inside cells was evidenced.

Zonal Intratumoral Delivery of Nanoparticles Guided by Surface Functionalization

Delivery of small molecules and anticancer agents to malignant cells or specific regions within a tumor is limited by penetration depth and poor spatial drug distribution, hindering anticancer efficacy. Herein, we demonstrate control over gold nanoparticle (GNP) penetration and spatial distribution across solid tumors by administering GNPs with different surface chemistries at a constant injection rate via syringe pump. A key finding in this study is the discovery of different zone-specific accumulation patterns of intratumorally injected nanoparticles dependent on surface functionalization. Computed tomography (CT) imaging performed in vivo of C57BL/6 mice harboring Lewis lung carcinoma (LLC) tumors on their flank and gross visualization of excised tumors consistently revealed that intratumorally administered citrate-GNPs accumulate in particle clusters in central areas of the tumor, while GNPs functionalized with thiolated phosphothioethanol (PTE-GNPs) and thiolated polyethylene glycol (PEG-GNPs) regularly accumulate in the tumor periphery. Further, PEG functionalization resulted in larger tumoral surface coverage than PTE, reaching beyond the outer zone of the tumor mass and into the surrounding stroma. To understand the dissimilarities in spatiotemporal evolution across the different GNP surface chemistries, we modeled their intratumoral transport with reaction-diffusion equations. Our results suggest that GNP surface passivation affects nanoparticle reactivity with the tumor microenvironment, leading to differential transport behavior across tumor zones. The present study provides a mechanistic understanding of the factors affecting spatiotemporal distribution of nanoparticles in the tumor. Our proof of concept of zonal delivery within the tumor may prove useful for directing anticancer therapies to regions of biomarker overexpression.