Poly maleic anhydride alt 1 octadecene

Lead (II) chloride (PbCl₂), 1-octadecene (ODE), cadmium oxide (CdO) and sulfur powder (sublimed) were purchased from Alfa Aesar. Oleylamine, oleic acid, 1-octadecene, poly(maleic anhydride-alt-1-octadecene) (PMH; average molecular weight: 30k-50k), 4-morpholineethanesulfonic acid (MES), 4-(dimethylamino)pyridine (DMAP), poly(acrylic acid) (PAA; average molecular weight: 1800), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), and 2-Amino-2-(hydroxymethyl)-1,3-propanediol (tris-base) were purchased from Sigma-Aldrich. Hexane, toluene, chloroform, and DI water were purchased from Fisher Scientific. Methoxy polyethylene glycol amine (mPEG-NH₂; average molecular weight: 5 kD) was purchased from Laysan-Bio. 8-arm polyethylene glycol amine (8Arm-PEG-NH₂‧HCl; average molecular weight: 40 kDa) was purchased from Advanced Biochemicals. All the chemicals were used without further purification. 50 μm capillaries were bought from VitroCom. Purified anti-mouse/human PNAd antibody (Clone: MECA-79), purified anti-mouse CD169 antibody (Clone: 3D6.112) and DRAQ7 (# 424001) were purchased from BioLegend. Anti-mouse CD3 antibody (Clone: KT3) was bought from Bio X Cell.

Previously synthesized KI NPs in 3 mL of chloroform was added to the mixture and sonicated into suspension. After which 120 mg Poly(maleic anhydride alt-1-octadecene) (Sigma-Aldrich, 776866) in 3 mL chloroform (Sigma-Aldrich, C2432) and 1 mL PEG-bis-amine (43 mg in 10 mL chloroform) (Sigma-Aldrich, P9906) were added. The reaction was then mixed for 2 hrs. The solution was then poured into a round bottom flask. The solvent was removed under a rotary evaporator and gentle heat (<40 °C) until dry. 1.5 mL bis-hexamethyl triamine (43 mg in 10 mL chloroform) (Fisher Scientific, B181425G) was added to the flask and sonicated until the film was resuspended. The solution was then placed under Rotovap again until dry at room temperature. 50 mM Borate buffer is then added to cover film and sonicated until film is fully in solution. After which the solution is filtered to remove excessive aggregates then centrifuged at 10,000 rpm for 10 minutes. After which and the supernatant is discarded and the precipitate dried below 120 °C to avoid polymer softening. The dried and sealed PMAO-KI NPs can be stored for at least 6 months with no discernable loss in quality.

1-Octadecene (tech. 90%), oleic acid (tech. 90%), and iron trichloride hexahydrate (ACS, 97.0-102.0%) were obtained from Alfa Aesar. Sodium oleate (>97%) was obtained from Tokyo Chemical Industry CO, LTD. Sodium hydroxide, sodium sulfate (anhydrous), potassium permanganate (99.2%), n-heptane, ethyl acetate and methylene chloride (HPLC grade) were obtained from Fisher Scientific. Hexane (mixture of isomers), chloroform, and acetone were HPLC grade and obtained from Sigma-Aldrich. Ethanol (200 proof) was obtained from Decon Labs. Phosphoric acid (85%), sulfuric acid and concentrated hydrochloric acid were obtained from Macron. 1% oxygen in argon was obtained from Praxair. Water used in any experiment was purified at 18.2 MOhm-cm. The DigiTrol II was obtained from Sigma-Aldrich. SUBA-SEAL^® septum were obtained from Chemglass. Poly(maleic anhydride-alt-1-octadecene) (average Mn 30,000-50,000 Da) was obtained from Sigma-Aldrich. Methoxy-poly(ethylene glycol)-amine, HCl salt was purchased from JenKem Technology USA.

Iron (III) chloride, anhydrous (98%) was purchased from Alfa-Aesar. Oleic acid (technical grade, 90%), 1-octadecene (technical grade, 90%), chloroform (HPLC, ≥99.8%), methanol (HPLC, ≥99.9%), poly(maleic anhydride-alt-1-octadecene) (Mn 30,000–50,000), N-(3-Dimethylaminopropyl)-N ′ - ethylcarbodiimide hydrochloride (commercial grade, powder), N-Hydroxysulfosuccinimide sodium salt (≥98%, HPLC), lactoferrin from human milk (≥85%, SDS-PAGE, lyophilized powder), paraformaldehyde powder (95%), potassium hexacyanoferrate (II) trihydrate, DAPI, alminum sulfate hydrate (98%), Dulbecco's phosphate buffered saline, and dimethyl sulphoxide (DMSO) Hybri-Max™ were purchased from Sigma-Aldrich. Sodium hydroxide solution 1N, hydrochloric acid 1N solution, and sodium bicarbonate were purchased from Fisher Scientific. Dulbecco's modified Eagle medium (DMEM) and 0.25% trypsin-EDTA were purchased from Gibco. Coomassie protein assay reagent was purchased from Thermo Scientific. All the reagents were used without further purification. Amicon^® Ultra centrifugal filters ultracel^®-50K was purchased from Merck Millipore. Cy5.5™ Mono NHS Ester was purchased from GE Health Care.