Starburst® PAMAM dendrimers are potential carriers for drug delivery due to their unique structure. Drug-delivery scaffolds were designed and built up based on the polyethylene glycolpolyamidoamine (PEG-PAMAM) star polymer. Penicillin V was used as a model carboxylic group containing drug to conjugate with full- and half-generation PAMAM dendrimers. G2.5 PAMAM (with 32 carboxylic groups on the surface) dendrimers and G3.0 (with 32 primary amine groups on the surface) were typically chosen. There are two strategies given in the paper where a drug carrying a carboxylic group (e.g. penicillin V) was coupled to star polymer via amide and ester bonds, respectively. FT-IR, UV-Vis and 1H-NMR were used to characterize the intermediates and drug-star polymer conjugates. A single-strain bacterium, Staphylococcus aureus, was grown up for penicillin-conjugated PEG-PAMAM (G3.0) star polymer activity test. The result verified the bioavailability of modified penicillin after the ester bond was cleaved.