IL-10 Gene Transfection in Primary Endothelial Cells via Linear and Branched Poly(β-amino ester) Nanoparticles Attenuates Inflammation in Stimulated Macrophages

Design and development of Branched Poly(ß-aminoester) nanoparticles for Interleukin-10 gene delivery in a mouse model of atherosclerosis

Atherosclerosis progression is a result of chronic and non-resolving inflammation, effective treatments for which still remain to be developed. We designed and developed branched poly(ß-amino ester) nanoparticles (NPs) containing plasmid DNA encoding IL-10, a potent anti-inflammatory cytokine to atherosclerosis. The NPs (NP-VHPK) are functionalized with a targeting peptide (VHPK) specific for VCAM-1, which is overexpressed by endothelial cells at sites of atherosclerotic plaque. The anionic coating affords NP-VHPK with significantly lower toxicity than uncoated NPs in both endothelial cells and red blood cells (RBCs). Following injection of NP-VHPK in ApoE^-/- mice, Cy5-labelled IL-10 significantly accumulates in both whole aortas and aortic sinus sections containing plaque compared to injection with a non-targeted control. Furthermore, IL-10 gene delivery results in an attenuation of inflammation locally at the plaque site. NP-VHPK may thus have the potential to reduce the inflammatory component of atherosclerosis in a safe and effective manner. STATEMENT OF SIGNIFICANCE: Atherosclerosis is a chronic inflammatory disease that results in the formation of lipid-laden plaques within vascular walls. Although treatments using drugs and antibodies are now beginning to address the inflammation in atherosclerosis, neither is sufficient for long-term therapy. In this paper, we introduce a strategy to deliver genes encoding the anti-inflammatory protein interleukin-10 (IL-10) in vivo. We showed that Branched Poly(ß-aminoester) carrying the IL-10 gene are able to localize specifically at the plaque via surface-functionalized targeting moieties against inflamed VCAM-1 and/or ICAM-1 and to facilitate gene transcription by ECs to increase the local concentration of the IL-10 within the plaque. To date, there is no report involving non-viral nanotechnology to provide gene-based therapies for atherosclerosis.

Development of an optimized freeze-drying protocol for OM-PBAE nucleic acid polyplexes

Long-term stability of polyplexes used for biomedical purposes is an objective envisaged by any research group developing this kind of nanoformulations. However, since biodegradable polymers such as oligopeptide end-modified poly (β-aminoester) (OM-PBAE) are frequently used to ensure safety, and formulations are produced as aqueous dispersions, the stability of the nanoformulations is usually compromised. In this context, freeze-drying has aroused as a promising storage alternative to obtain solid nanoformulations with enhanced stability over time. Lyophilization is a challenging step that usually produces aggregation. Although some studies already achieved freeze-dried PBAE nanoparticles, none of them detailed the parameters that are critical for the success of this process. Moreover, due to the specific composition of each formulation, the critical parameters for the correct freeze-drying process need to be adjusted for each polyplex developed. In this paper, we have studied the variables that have a direct influence on the manufacturing and lyophilization of OM-PBAE nanoparticles with the aim to develop a versatile and robust freeze-drying receipt that properly preserves the library of polyplexes designed in our group, which have different pKa depending on the modification applied.