Study on the transfection efficiency of chitosan-based gene vectors modified with poly-l-arginine peptides

Plasma Modification Techniques for Natural Polymer-Based Drug Delivery Systems

Natural polymers have attracted significant attention in drug delivery applications due to their biocompatibility, biodegradability, and versatility. However, their surface properties often limit their use as drug delivery vehicles, as they may exhibit poor wettability, weak adhesion, and inadequate drug loading and release. Plasma treatment is a promising surface modification technique that can overcome these limitations by introducing various functional groups onto the natural polymer surface, thus enhancing its physicochemical and biological properties. This review provides a critical overview of recent advances in the plasma modification of natural polymer-based drug delivery systems, with a focus on controllable plasma treatment techniques. The review covers the fundamental principles of plasma generation, process control, and characterization of plasma-treated natural polymer surfaces. It discusses the various applications of plasma-modified natural polymer-based drug delivery systems, including improved biocompatibility, controlled drug release, and targeted drug delivery. The challenges and emerging trends in the field of plasma modification of natural polymer-based drug delivery systems are also highlighted. The review concludes with a discussion of the potential of controllable plasma treatment as a versatile and effective tool for the surface functionalization of natural polymer-based drug delivery systems.

A cationic lipid with advanced membrane fusion performance for pDNA and mRNA delivery

The success of mRNA vaccines for COVID-19 prevention raised global awareness of the importance of nucleic acid drugs. The approved systems for nucleic acid delivery were mainly formulations of different lipids, yielding lipid nanoparticles (LNPs) with complex internal structures. Due to the multiple components, the relationship between the structure of each component and the overall biological activity of LNPs is hard to study. However, ionizable lipids have been extensively explored. In contrast to former studies on the optimization of hydrophilic parts in single-component self-assemblies, we report in this study on structural alterations of the hydrophobic segment. We synthesize a library of amphiphilic cationic lipids by varying the lengths (C = 8-18), numbers (N = 2, 4), and unsaturation degrees (Ω = 0, 1) of hydrophobic tails. Notably, all self-assemblies with nucleic acid have significant differences in particle size, stability in serum, membrane fusion, and fluidity. Moreover, the novel mRNA/pDNA formulations are characterized by overall low cytotoxicity, efficient compaction, protection, and release of nucleic acids. We find that the length of hydrophobic tails dominates the formation and stability of the assembly. And at a certain length, the unsaturated hydrophobic tails enhance the membrane fusion and fluidity of assemblies and thus significantly affect the transgene expression, followed by the number of hydrophobic tails.

A Ternary Synergistic eNOS Gene Delivery System Based on Calcium Ion and L-Arginine for Accelerating Angiogenesis by Maximizing NO Production

Purpose

This study aimed to construct a delivery system based on L-arginine-modified calcium phosphate (CaP) to load eNOS plasmids (peNOS), which could amply nitric oxide (NO) to repair endothelial damage, promote angiogenic activities and alleviate inflammation.

Methods

pDNA-loaded CaP nanocomplex (CaP/pDNA) were prepared by co-precipitation method, subsequently modified by L-arginine. The gene transfection efficiency, pro-angiogenic and anti-inflammatory ability were investigated in vivo and in vitro. The therapeutic effect on ischemic hindlimb in vivo was assessed.

Results

L-arginine modification augmented the transfection efficiency of CaP/peNOS to elevate the eNOS expression, and then served as NO substrate catalyzed by eNOS. At the same time, calcium ions produced by degradation of CaP carriers enhanced the activity of eNOS. In vitro experiments, the loading capability and transfection performance of R(L)-CaP were confirmed to be superior to that of CaP. Additionally, HUVECs treated with R(L)-CaP/peNOS showed the strongest NO release, cell migration, tube formation and the lowest inflammatory levels compared to the CaP/peNOS and R(D)-CaP/peNOS groups. We also demonstrated the advantages of R(L)-CaP/peNOS in increasing blood reperfusion in hindlimb ischemia mice by accelerating angiogenesis and reducing inflammation, which can be attributed to the highest eNOS-derived NO production.

Conclusion

The combination strategy of peNOS transfection, L-arginine supplement and calcium ions addition is a promising therapeutic approach for certain vascular diseases, based on the synergistic NO production.