Thiol capped poly(D,L-Lactide) (Thiol-PDLLA-OH, HO-PDLLA-SH or HS-PDLLA-OH) can be used to prepare nanoparticles, which can be further modified through -SH groups on the nanoparticle surface. Thiol can selectively react with maleimide and transition metal surface including gold, silver, etc.
Polylactides are a family of biodegradable and bioactive thermoplastic aliphatic polyester. It is used to fabricate resorbable medical devices that degrade over months in physiological conditions. Due to their history, polylactides are one of the easiest and most affordable biodegradable polymers for medical devices. PDLLA polymer is amorphous because the polymer composed randomly by the repeating units from L-lactic acid and D-lactic acid. Therefore, the polymer did not show melting point and has inferior mechanical properties than PLLA, so that the polymer is mainly applied for the coating of suture.