Enhanced Intracellular Delivery and Cell Harvest Using a Candle Soot-Based Photothermal Platform with Dual-Stimulus Responsiveness

Abstract

Intracellular delivery of bioactive macromolecules and functional materials plays a crucial role in fundamental biological research and clinical applications. Nondestructive and efficient harvesting of engineered cells is also required for some specific applications. In this work, we develop a multifunctional platform based on candle soot modified with copolymer brushes containing temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and sugar-responsive phenylboronic acid (PBA) components. This platform possesses a high cell adhesion capacity due to the inherent hierarchical structure of candle soot and the formation of boronate ester bonds between the PBA groups and glycoproteins on the cell membrane. Under the irradiation of a near-infrared laser, the excellent light-to-heat conversion ability of candle soot enables the highly efficient delivery of macromolecules into diverse cells (including hard-to-transfect cells) attached to the surface via a photothermal-poration mechanism. Owing to the temperature-responsive properties of PNIPAAm and the sugar-responsive properties of PBA, the engineered cells could be harvested nondestructively from the platform by a mild treatment using a cold fructose solution. A proof-of-concept experiment demonstrates that fibroblasts attached to the surface could be transfected by a functional plasmid encoding basic fibroblast growth factor and then harvested efficiently and recultured with improved proliferation and migration ability. The whole delivery-harvesting process required less than 1 h, allowing the cells to be engineered without compromising their viability. This platform thus provides a widely applicable method for both the intracellular delivery of diverse macromolecules efficiently as well as harvesting engineered cells simply and safely, holding great potential for biomedical applications.

Nordihydroguaiaretic Acid-Cross-Linked Phenylboronic Acid-Functionalized Polyplex Micelles for Anti-angiogenic Gene Therapy of Orthotopic and Metastatic Tumors

“…The introduction of the hydrophobic moieties into PEG- b -polycationic block copolymers is recognized as a valid strategy to improve the colloidal stabilities of the pDNA-based polyplex micelles by virtue of the favorable hydrophobic interactions. , In particular, there has been rising interest in utilizing phenylboronic acid (PBA) and its derivatives as functional components in fabrication of nonviral gene delivery systems. , These components are acknowledged to exist in equilibrium as the uncharged trivalent form and the negatively charged tetravalent form in aqueous milieu. , Of note, the tetravalent boronate could selectively form stable ester linkage with diols, particularly favorable in a physiological or relatively alkaline microenvironment. − Based on the unique characteristic of PBA, Yoshinaga et al developed PBA/ d -gluconamide (GlcAm) cross-linked polyplex micelles for construction of pDNA delivery systems, thereby accomplishing enhanced structural stabilities of polyplex micelles in extracellular conditions. Moreover, the acidic pH in the endolysosomes is determined to assist the breakage of phenylboronate ester linkages and the protonation of amino groups for polyplex micelles residing in acidic endolysosomes, thereby promoting the selective release of PEG- b -PAsp­(DET/FPBA) and PEG- b -PAsp­(DET/GlcAm) in endolysosomal compartments.…”