Dextran dex

Poly(L-lysine hydrobromide) (PLL-HBr, M_w = 7.5 × 10³) and dextran (Dex, M_w = 8.0 × 10³–1.2 × 10⁴) were obtained from Sigma-Aldrich (St. Louis, MO, USA) and Funakoshi Co. (Tokyo, Japan), respectively. Sodium hydroxide, sodium chloride and manganese(II) chloride tetrahydrate were purchased from Wako Pure Chemical Industries (Osaka, Japan). 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid (HEPES) was obtained from Nacalai Tesque, Inc. (Kyoto, Japan). Poly(L-lysine)-graft-Dextran (PLL-g-Dex) cationic comb-type copolymer was synthesized by a reductive amination reaction of dextran with PLL according to [14 (link)]. The resulting copolymer was purified by an ion exchange column and dialysis, and obtained by freeze drying. ¹H nuclear magnetic resonance spectrometer and gel permeation chromatography equipped with a multi angle light scattering detector were employed to characterize the resulting copolymer. PLL-g-Dex copolymer consisting of 10 wt% PLL and 90 wt% dextran (11.5 mol.% of lysine units of PLL were substituted with dextran) was used in this study (Figure 1). HPLC-grade oligonucleotide with LNA modification was purchased from Gene Design Inc. (Osaka, Japan). HPLC-grade oligonucleotides with the sequences summarized in Figure 2(a) except that with LNA modification were purchased from Fasmac Co., Ltd (Kanagawa, Japan) and used without further purification.

Gel-B (dry content 91.3%, Mw = 209,600 g·mol ${}^{-1}$ ) and Gel-R (dry content 86.5%, Mw = 157,800 g·mol ${}^{-1}$ ) were obtained from Tanex Vladislav, a.s. Gel-C (dry content 92.7%, Mw = 190,900 g·mol ${}^{-1}$ ) was prepared according to a patented biotechnological process [37 ], which is described in detail in Mokrejš et al., 2019 [38 (link)] and Gál et al., 2020 [39 (link)]. Dextran (Dex) Mw = 40,400 g·mol ${}^{-1}$ , sodium periodate, and phosphate-buffered saline sterile solution (PBS), pH 7.4, were obtained from Sigma Aldrich. Demineralized (DEMI) water was prepared using Milipore Q System. Ammonia solution, 30 vol% was purchased from Penta and diluted to 25 vol%. Na ${}_2$ HPO ${}_4$ .12H ${}_2$ O and NaH ${}_2$ PO ${}_4$ .2H ${}_2$ O, used for the preparation of PBS pH 7, were obtained form Lach-Ner.