Glioblastoma multiforme (GBM) is the most common and lethal primary brain cancer. Current pharmacological interventions marginally increase the 12-month overall survival of patients with GBM. Among the novel therapeutic strategies being pursued, micro-RNAs, a class of non-coding RNAs, are receiving considerable attention for their regulation of several pathways implicated in tumorigenesis and survival. Notably, microRNA-181a-5p (miR-181a) has consistently been reported to be downregulated in GBM clinical samples, and its overexpression negatively affects tumor growth both in vitro and in vivo. To improve the delivery of miR-181a to GBM cells, we sought to develop a modified lipid-based nanocarrier capable of encapsulating and delivering miR-181a to GBM cells in vitro and in vivo. Optimized ionizable-lipid containing lipid nanoparticles (LNP) were constructed by covering the miR-181a-loaded LNP with alternating layers of miR-181a, poly-l-arginine and hyaluronic acid through the layer-by-layer technique. The resulting hyaluronan-decorated lipid nanoparticles (HA-LNP) targeted GBM cells more efficiently than non-modified LNP and mediated siRNA and miRNA transfection in vitro. Finally, delivery of miR-181a by HA-LNP induced significant cellular death of U87 GBM cells in vitro and delayed tumor growth in an in vivo subcutaneous tumor model.

The chemical structure of a delivery nanovehicle plays a pivotal role in determining the efficiency of drug delivery within the body. Leveraging the unique architecture of bottlebrush (BB) polymers—characterized by variations in backbone length, grafting density, and self‐assembly morphology—offers a novel approach to understanding the influence of structural properties on biological behavior. In this study, developed a drug delivery system based on core‐shell BB polymers synthesized using a “grafting‐from” strategy. Comprehensive characterization techniques, including nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and atomic force microscopy (AFM), employed to confirm the polymers’ structure. The BB polymers evaluated as carriers for molecules with differing hydrophobicity profiles, namely Rhodamine B and Paclitaxel. These nanocarriers systematically assessed for drug loading efficiency and penetration capabilities, compared to conventional polymeric micelles (PM) formed from linear amphiphilic polymers. BB‐based nanocarriers exhibited superior cellular uptake in both 2D and 3D cell culture models when compared to PM. Furthermore, analysis of drug distribution and particle penetration highlighted the profound influence of polymer morphology on biological interactions. These findings underscore the potential of unimolecular carriers with precisely defined structures as promising drug delivery platforms for a wide range of biomedical applications.

Lipid nanoparticles (LNPs) have established their position as nonviral vectors for gene therapy. Tremendous efforts have been made to modulate the properties of LNPs to unleash their full clinical potential. Among the strategies being pursued, the layer-by-layer (LbL) technique has gained considerable attention in the biomedical field. Illuminated by our previous work, here we investigate if the LbL approach could be used to modify the LNP cores formulated with three different ionizable lipids: DODMA, MC3, and DODAP. Additionally, we wondered if more than three layers could be loaded onto LNPs without disrupting their gene transfection ability. Taking advantage of physicochemical analysis, as well as uptake and gene silencing studies, we demonstrate the feasibility of modifying the surface of LNPs with the LbL assembly. Precisely, we successfully modified three different LNPs using the layer-by-layer strategy which abrogated luciferase activity in vitro. Additionally, we constructed a 5×-layered HA-LNP containing the MC3 ionizable lipid which outperformed the 3×-layered counterpart in transfecting miRNA-181-5p to the pediatric GBM cell line, as a proof-of-concept in vitro experiment. The method used herein has been proven reproducible, of easy modification to adapt to different ionizable lipid-containing LNPs, and holds great potential for the translation of RNA-based therapeutic strategies.