Synthesis of well-defined star, star-block, and miktoarm star biodegradable polymers based on PLLA and PCL by one-pot azide-alkyne click reaction.

Based on the "arm-first" strategy, ring-opening polymerization (ROP) and one-pot azide-alkyne click reaction, well-defined star-shaped polymers with different architectures have been successfully synthesized, including the star homopolymers four-arm star-shaped polycaprolactone (4sPCL) and four-arm star-shaped poly(l-lactic acid) (4sPLLA), star-block copolymer 4sPCL--PLLA and miktoarm star-shaped copolymer PCLPLLA. The star homopolymers 4sPCL and 4sPLLA were synthesized by a click reaction of an azide small molecule initiator and HC[triple bond, length as m-dash]C-PCL or HC[triple bond, length as m-dash]C-PLLA. The star-block copolymer 4sPCL--PLLA was synthesized by a click reaction of an azide small molecule initiator and the block copolymer HC[triple bond, length as m-dash]C-PCL--PLLA.

Preparation of thermo-responsive drug-loaded nanofibrous films created by electrospinning.

We prepared thermosensitive and biocompatible drug-loaded nanofibrous films by an electrospinning technique using a block copolymer, poly(-isopropylacrylamide)--poly(l-lactide) (PNLA), and poly(l-lactide) (PLLA). The copolymer PNLA was synthesized by the radical polymerization of -isopropylacrylamide (NIPAAm), followed by the ring-opening polymerization of l-lactide. The properties of PNIPAAm and PNLA were selectively discussed based on the results of NMR, FT-IR, GPC, and CA analyses.