Li et al. Nanoscale Res Lett 2011, 6:29 http://www.nanoscalereslett.com/content/6/1/29 N A N O E X P R E S S Open Access Novel Strategy to Fabricate PLA/Au Nanocomposites as an Efficient Drug Carrier for Human Leukemia Cells in Vitro Jingyuan Li1, Chen Chen1, Xuemei Wang1*, Zhongze Gu1, Baoan Chen2 Abstract Poly (lactic acid) (PLA) polymer has the promising applications in the biomedical field because of its biodegradability and safe elimination. In this study, we have explored the bio-application of new nanocomposites composed with PLA nanofibers and Au nanoparticles as the potential drug carrier for an efficient drug delivery in target cancer cells. The results demonstrated that the anticancer drug daunorubicin could be efficiently self-assembled on the surface of PLA/Au nanocomposites and the synergistic enhancement of PLA/Au nanocomposites conjugated with daunorubicin into drug-sensitive K562 and drug-resistant leukemia K562/AO2 cells could be obviously observed by MTT assay and confocal fluorescence microscopy studies. These observations suggest that the new nanocomposites could readily induce daunorubicin to accumulate and uptake in target leukemia cells and increase the drug’s cytotoxicity. Especially, the PLA/Au nanocomposites could significantly facilitate the cellular drug absorbtion of daunorubicin into drug-resistant K562/AO2 cells and efficiently inhibit the cancer cell proliferation. This raised the possibility to utilize the PLA/Au nanocomposites as a new effective additive agent to inhibit the drug resistance and thus as a novel strategy to sensitively track the respective cancer cells. Introduction As one of the difficult treated diseases, cancer threats the life of many patients. To reduce the morbidity and mortality of cancer, early diagnosis and cancer systemic therapies are of paramount importance. The cure effi- ciency of cancer chemotherapy depends not only on the anticancer drug itself but also on how the drug reagent is efficiently delivered to its targets [1]. Although there is much effort to solve the relevant problems, it is still a big challenge to develop a new strategy to mark and track the target cancer cells for the early diagnosis and cure of cancers. Besides, the emergence of drug resis- tance is a worldwide puzzle in the related diseases’ therapies, while the occurrence of the multidrug resis- tance (MDR) phenomenon is one of the major obstacles to the success of the tumors’ chemotherapy [2,3]. It is noted that the mechanisms involved in drug resistance of cancer cells are pertaining to multifactor processes. And the cellular uptake of some drugs may be poor by * Correspondence: xuewang@seu.edu.cn 1State Key Lab of Bioelectronics (Chien-Shiung WU Laboratory), Southeast University, 210096, Nanjing, China. Full list of author information is available at the end of the article the mutated tumor cells. The proteins related with drug resistance may pump out the drug molecules from the mutated tumor cells, which will decrease the drug con- centration inside the tumor cells [4]. Thus, the efficient targeting of drug delivery for relevant cancer cells could afford a new strategy for the effective treatment of tar- geted cancers [5,6]. Recently, some reports have demonstrated that antic- ancer drugs could be readily modified on the biocompa- tible nanomaterials covalently or non-covalently, which could afford the sustained drug delivery for the target cancer cell lines and reduce the relevant toxicity toward normal cells and tissues [7-9]. For instance, some semi- conductor nanoparticles such as TiO2 nanoparticles can penetrate across barriers into cancer cells to allow effi- cient drug accumulation at the targeted locations, which could have promising application in biomedical and bioengineering fields due to its oxidizing and biocompa- tible properties, chemical inertness and photoactivity [10-16]. Au nanoparticles were also applied as a poten- tial carrier or protective container for biologically active agents [8]. With the characteristics of biocompatibility, biodegradability and absorbability, some polymers have © 2010 Li et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.