A research paper by Jiangsu University professors published in European Cells & Materials

Recently, a research paper entitled “Incorporating pTGF-β1/calciumphosphate nanoparticles with fibronectin into 3-dimensional collagen/chitosanscaffolds: Efficient, sustained gene delivery to stem cells for chondrogenicdifferentiation ”was published in the internationally prestigious journalEuropean Cells & Materials（23:81-93,2012）. The paper was written by a research team headed by professor XuXiming, dean of Jiangsu University Pharmacy School .The objective of this studywas to prepare a 3-dimensional nanoparticle gene delivery system (3D-NGDS)based on collagen/chitosan scaffolds, in which plasmid transforming growthfactor beta 1 (TGF-β1)/calcium phosphate nanoparticles mixed with fibronectin(FN) were used to transfect mesenchymal stem cells (MSCs). Scanning electronmicroscopy was used to characterise the microstructure of 3-dimensionalcollagen/chitosan scaffolds. An analysis performed to quantify the TGF-b1concentrations in MSC cultures revealed that the MSCs transfected with the3D-NGDS showed remarkably high levels of TGF-b1 over long periods, retaining aconcentration of TGF-b1 of approximately 10 ng/mL within two weeks, with thehighest level (12.6 ng/mL) being observed on the 6th day. Animmunohistochemistry analysis for collagen type II revealed that much higherproduction of collagen II from the 9th to 15th day was observed in the3D-NGDS-transfected MSCs than that in MSCs transfected by the Lipofectamine2000 method. The glycosaminoglycan content of the 3D-NGDS was comparable tothose treated with TGF-β1 as well as TGF-β1 plus dexamethasone, and wassignificantly higher than those treated with free plasmid and Lipofectamine2000. A remarkable type I collagen expression inhibition of the 3D-NGDS at day21 was observed via ELISA. These results suggested that transfection with the3D-NGDS could successfully induce MSC chondrogenic differentiation in vitrowithout dexamethasone. The research team has made applications for Chinese andAmerican invention patents.