Synthesis of alternating copolymer PAspNa-alt-PAsp(Pr) for drug delivery system

Alternating copolymers (ACs) contain two distinct monomeric unit types dispersed in alternating order of hydrophilic block and hydrophobic block. ACs have extensive and versatile applications in both academia and industry, especially in drug delivery systems (DDS) due to their unique physical and chemical properties. In the present research, poly(beta-benzyl l-aspartate) (PBLA) was prepared by ring-opening polymerization of BLA-NCA. The result obtained from GPC showed that PBLA was successfully synthesized with narrow weight distribution Mw/Mn = 1.055. The outcome of copolymer has the degree of polymerization (DP) of PBLA was 50 based on the 1H NMR spectroscopy. Further, alternating copolymer poly(aspartate-sodium) alternating poly(aspartate-R) (PAspNa-alt-PAsp(Pr)), which allows the installation of expected compounds into a polymer backbone of PBLA without unwanted side effects, was synthesized via 2 steps: (1) aminolysis by 0.5 fold primary amine to attach hydrophobic group and (2) hydrolysis slowly by NaOH solution to form the hydrophilic group on the side chain of the polymer. The novel alternating copolymer synthesized successfully in this study was expected to be a promising candidate for drug delivery devices.