Amphiphilic Copolymer-Lipid Chimeric Nanosystems as DNA Vectors

Tannic acid cross-linked polyethylenimine quantum dot nanoclusters for efficient DNA release

In this work, we present a strategy for synthesizing nanoclusters (TC25NCs) by bonding formaldehyde functionalized tannic acid (TA-CHO) with polyethyleneimine quantum dots (CQDs). The synthesized vector effectively loads DNA and exhibits significant pH-responsive release, thereby facilitating traceable DNA delivery in cells. The TC25NCs/DNA demonstrated negligible cytotoxicity at high N/P ratios, with cell viability exceeding 80 %. Utilizing the excellent fluorescence imaging capability of TC25NCs, real-time monitoring of cell uptake and quantitative analysis of uptake efficiency were achieved. The results indicated that TC25NCs exhibited significant fluorescence effects at an excitation wavelength of 350 nm, with transfection efficiencies of 58.88 %, 42.69 %, and 35.25 % in 293T, HepG2, and HeLa cells, respectively, which were substantially higher than those of other single vector materials. This work not only provides an effective carrier for DNA delivery, but also offers valuable insights into tailoring surface chemistry and designing vectors for precise control over delivery process to achieve the visual delivery of genes.

Phospholipids of inhaled liposomes determine the in vivo fate and therapeutic effects of salvianolic acid B on idiopathic pulmonary fibrosis

Since phospholipids have an important effect on the size, surface potential and hardness of liposomes that decide their in vivo fate after inhalation, this research has systematically evaluated the effect of phospholipids on pulmonary drug delivery by liposomes. In this study, liposomes composed of neutral saturated/unsaturated phospholipids, anionic and cationic phospholipids were constructed to investigate how surface potential and the degree of saturation of fatty acid chains determined their mucus and epithelium permeability both in vitro and in vivo. Our results clearly indicated that liposomes composed of saturated neutral and anionic phospholipids possessed high stability and permeability, compared to that of liposomes composed of unsaturated phospholipids and cationic phospholipids. Furthermore, both in vivo imaging of fluorescence-labeled liposomes and biodistribution of salvianolic acid B (SAB) that encapsulated in liposomes were performed to estimate the effect of phospholipids on the lung exposure and retention of inhaled liposomes. Finally, inhaled SAB-loaded liposomes exhibited enhanced therapeutic effects in a bleomycin-induced idiopathic pulmonary fibrosis mice model via inhibition of inflammation and regulation on coagulation-fibrinolytic system. Such findings will be beneficial to the development of inhalable lipid-based nanodrug delivery systems for the treatment of respiratory diseases where inhalation is the preferred route of administration.

Self-Assembly of Symmetric Copolymers in Slits with Inert and Attractive Walls

Although the behavior of the confined semi-dilute solutions of self-assembling copolymers represents an important topic of basic and applied research, it has eluded the interest of scientists. Extensive series of dissipative particle dynamics simulations have been performed on semi-dilute solutions of A5B5 chains in a selective solvent for A in slits using a DL-MESO simulation package. Simulations of corresponding bulk systems were performed for comparison. This study shows that the associates in the semi-dilute bulk solutions are partly structurally organized. Mild steric constraints in slits with non-attractive walls hardly affect the size of the associates, but they promote their structural arrangement in layers parallel to the slit walls. Attractive walls noticeably affect the association process. In slits with mildly attractive walls, the adsorption competes with the association process. At elevated concentrations, the associates start to form in wide slits when the walls are sparsely covered by separated associates, and the association process prevents the full coverage of the surface. In slits with strongly attractive walls, adsorption is the dominant behavior. The associates form in wide slits at elevated concentrations only after the walls are completely and continuously covered by the adsorbed chains.