Polylactide (PLA)-based amphiphilic block copolymers: synthesis, self-assembly, and biomedical applications

Polylactide (PLA) and its copolymers are one type of hydrophobic aliphatic polyester based on hydroxyalkanoic acids. They possess exceptional qualities: biocompatibility; FDA approval for clinical use; biodegradability by enzyme and hydrolysis under physiological conditions; low immunogenicity; and good mechanical properties. These critical properties have facilitated their value as sutures, implants for bone fixation, drug delivery vehicles, and tissue engineering scaffolds in pharmaceutical and biomedical applications. However, the hydrophobicity of PLA and its copolymers remains concerns for further biological and biomedical applications. One promising approach is to design and synthesize well-controlled PLA-based amphiphilic block copolymers (ABPs); typical hydrophilic copolymers include poly(meth)acrylates, poly(ethylene glycol), polypeptides, polysaccharides, and polyurethanes. This review summarizes recent advances in the synthesis and self-assembly of PLA-containing ABPs and their bio-related applications including drug delivery and imaging platforms of self-assembled nanoparticles, and tissue engineering of crosslinked hydrogels.