Erratum to: J Nanopart Res (2013) 15:2096 DOI 10.1007/s11051-013-2096-1

The original paper “Folate-conjugated chitosan–polylactide nanoparticles for enhanced intracellular uptake of anticancer drug” was published in the Journal of Nanoparticle Research, 2013, 15:2096. The description for the synthesis of folate-conjugated chitosan-polylactide (FA-CH-PCL), which appeared in the page 3 of 15, right column, lines: 11–35, was not correct and is replaced with the following statement.

“Polylactide (PLA) was grafted onto CH following group-protection methods with some modifications (Duan et al. 2010; Zhou et al. 2013; Feng and Dong 2007). In a typical procedure, 1 g of CH was dissolved in 30 mL of methanesulfonic acid, followed by addition of 2.57 g of LA monomer and 0.73 g of 4-dimethylaminopyridine. The reaction was allowed to perform for 12 h at 120 °C with stirring while bubbling with nitrogen. The resulting mixture was then transferred to a beaker that contained 200 mL of 0.2 M KH2PO4, 20 mL of 4 M NaOH and was cooled in a bath (0 °C) to remove the acid residue. The collected precipitate was extracted with toluene to remove PLA homopolymers. Afterward, the product was dialyzed against distilled water for 2 days using a membrane tube (MW cutoff: 10 kD) and lyophilized for further use. By mainly changing the feed ratio of LA to CH, several types of CH-PLA copolymers were synthesized using the same protocol. Folate was then conjugated onto CH–PLAs using the method as the same as that described in the synthesis of FA–CH and FA-substitution degree for FA-CH-PLAs was controlled around 10 wt% or lower.”