1 1 4 7 10 10 hexamethyltriethylenetetramine

R6G (99%), DOX hydrochloride (DOX, 98.0–102.0%), AH (pharmaceutical secondary standard), CARB (pharmaceutical secondary standard), PHEN (pharmaceutical secondary standard), 3MA (≥99%), C3 (99%), 1-undecanethiol (C11, 98%), 4-MBA (99%), 4-MPBA (90%), D-(−)-fructose (≥99%), PBS packet (pH 7.4 and ionic strength 150 mM), copper(I) bromide (99.999%), copper(II) bromide (99.999%), 1,1,4,7,10,10-hexamethyltriethylenetetramine (97%) were purchased from Sigma-Aldrich (St Louis, MO). The OEG-terminated thiol (HS(CH₂)₁₁(OCH₂)₄OH) was purchased from ProChimia (Poland). The DOXol hydrochloride (DOXol, ≥90%) was purchased from Toronto Research Chemicals (Canada). Ethanol (200 Proof) was purchased from Decon Laboratories (King of Prussia, PA). Pooled human plasma (in sodium heparin, mixed gender) was purchased from Biochemed Services (Winchester, VA). High-purity deionized (DI) water was obtained with a Millipore water purification system with a minimum resistivity of 18.2 MΩ cm.

Glycerol, sebacic acid, triethylamine (TEA), anhydrous tetrahydrofuran (THF), bromoisobutyryl bromide (BIBB), polyethylene glycol methyl ether methacrylate (PEGMEMA), 1,1,4,7,10,10-Hexamethyltriethylenetetramine (HMTETA), copper (I) bromide, doxorubicin, triethylamine (TEA), ethyl α-bromoisobutyrate (EBIB) and α-cyclodextrin (αCD) were purchased from Sigma-Aldrich, Nucleos, Singapore. Dulbecco’s modified eagle medium (DMEM), MTT and cell culture reagents was purchased from Life Technologies (Carlsbad, CA, USA).

3,4-Dimethoxythiophene (>97%), p-toluenesulfonic acid monohydrate (p-TSA, 98%), and magnesium sulfate (anhydrous 99.5%) were all purchased from Fluorochem (Derbyshire, UK). Triethylamine (TEA, >99.5%), 3-aminopropyl-trimethoxysilane (APTES, 98%), α-bromoisobutyryl bromide (BIB, 98%), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA, 97%), copper(II) bromide (99.999%), copper(I) bromide (99.999%), and DMF (>99.9%) were purchased from Sigma-Aldrich (St Louis, MO, USA). Dichloromethane (DCM, p.a.), chloroform (p.a.), toluene (p.a.), dimethylformamide (DMF, p.a.), tetrahydrofuran (THF, p.a.), methanol (p.a.), ethanol (99.9%), hydrogen peroxide (30% p.a.), and ammonia solution (30% p.a.) were all purchased from Chempur (Piekary Slaskie, Poland). Hydrochloric acid (35–38% p.a.) was obtained from POCH S. A. (Gliwice, Poland). 1,1,1-Tris(hydroxymethyl)ethane (>98%) was obtained from TCI Co. (Tokyo, Japan). Iron(III) chloride (99.5%) was purchased from Lab-Scan (Gliwice, Poland). Distilled chloroform and methanol used for sample purification after oxidative polymerization were additionally dried under molecular sieves (0.3 nm, Merck, Darmstadt, Germany) before use. The rest of the chemicals were used as received.