Sodium poly 4 styrene sulfonate

Tetrachloroauric acid trihydrate (99.99%), sodium citrate dihydrate (≥ 99%), Triton X-100 (laboratory grade), sodium borohydride (≥ 98%), silver nitrate (> 99%), poly(ethylene glycol) methyl ether thiol (mw 2000), poly(allylamine) hydrochloride (PAH, mw 50000), sodium poly(4-styrene sulfonate) (PSS, mw 70000), nitric acid (≥ 65%), nitric acid (1M), hydrochloric acid (≥ 37%), sulfuric acid (95.0–97.0%), hydrogen peroxyde (30% w/w), ethanol (≥ 99.8%), 2-propanol (99.5%), and ethyl cellulose (10 cP; 22 cP; 46 cP; 100 cP) were bought from Sigma Aldrich (Milano, Italy); α-mercapto,ω-carboxy poly(ethylene glycol) (mw 3000), poly(ethylene glycol) methyl ether thiol (mw 5000), poly(ethylene glycol) methyl ether thiol (mw 10000), and poly(ethylene glycol) methyl ether thiol (mw 20000) were bought RAPP Polymere (Tübingen, Germany); Ethylene glycol (99.5%) and ammonia solution in water (30% w/w) were bought from Carlo Erba Reagenti S.p.A. (Milano, Italy) Glass coverslides (22 × 26 mm, 0.14 mm thickness) were bought from Delchimica Scientific Gòassware (Napoli, Italy).

Iron(II) sulfate, ammonium chloride, 25% ammonia solution, and o-phosphoric acid were purchased from Reakhim (Moscow, Russia). Sodium hydroxide was obtained from LenReaktiv (St. Petersburg, Russia). 1,2-Propylene glycol was the product of EKOS-1 (Moscow, Russia). D-Glucose monohydrate was obtained from LenReaktiv (St. Petersburg, Russia). Anhydrous sodium hydrogen phosphate (≥99.0%) and potassium dihydrogen phosphate (≥99.5%) used to prepare the buffer solutions were purchased from Sigma-Aldrich (St. Louis, MO, USA). All chemicals were of analytical grade and were used as received. Dextran ((C₆H₁₀O₅)_n M_r~40.000), sodium poly(4-styrenesulfonate) (PSS, M_r~70.000) and branched polyethylenimine (PEI, M_r~25,000) were obtained from Sigma-Aldrich, DOX (lyophilizate for solution for injection, 10 mg/ampoule) was obtained from Pharmachemie (Petah Tikva, Israel). All solutions were prepared using ultrapure water obtained from a Milli-Q system, Millipore Corporation (Millipore SAS, Molsheim, France).