OBJECTIVE:To study the absorption features of Silymarin enteric coated-polyllactic-co-glycolic acid (PLGA) nanoparticles in rat in situ intestine perfusion model and colonic adenoma Caco-2 cell model. METHODS:HPLC method was used to determine the content of silymarin. The absorption rate constant(Ka)and apparent absorption coefficient(Kapp)of Silymarin sus-pension,Silymarin PLGA nanoparticles and Silymarin enteric coated-PLGA nanoparticles were investigated in duodenum,jejunum, ileum and colon of rat in situ intestine perfusion model;the apparent permeability coefficient (Papp) of those drugs containing low-concentration,medium-concentration and high-concentration(20,40,60 μg/mL)of silymarin in Caco-2 cell model were also investigated. RESULTS:Compared with Silymarin suspension,Ka and Kapp of Silymarin PLGA nanoparticles and Silymarin enteric coated-PLGA nanoparticles were all increased in duodenum,jejunum,ileum and colon(P<0.05);compared with the correspond-ing concentration Silymarin suspension,two-way Papp of Silymarin PLGA nanoparticles and Silymarin enteric coated-PLGA nanopar-ticles containing low-concentration,medium-concentration and high-concentration of silymarin were all increased in Caco-2 cell model (P<0.05);there was no statistical significance between Silymarin PLGA nanoparticles and Silymarin enteric coated-PLGA nanoparticles (P>0.05). CONCLUSIONS:Silymarin enteric coated-PLGA nanoparticles can effectively increase the intestinal ab-sorption,cellular uptake and transmembrane transport rate of silymarin.

Objective:To compare the effects of gelatin(Gel)and polydopamine(PDA)modification of polycaprolactone(PCL)on the biological behaviour and osteogenic function of osteoblasts.Methods:PCL electrospun membranes were prepared by electrostatic spinning technique,PCL surface was modified by Gel and PDA respectively as G/PCL and D/PCL with chemical self-assembly tech-nique,and the physicochemical properties of the electrospun membranes were characterized by scanning electron microscopy(SEM),Fourier infrared spectroscopy(FTIR),X-ray photoelectron spectroscope(XPS)and contact angle measurement.The MC3T3-E1 cell adhesion morphology was observed by SEM,immunofluorescence staining followed by confocal microscopy(CLSM),cell proliferation at 1,3 and 5 d was tested by CCK-8 assay,alkaline phosphatase(ALP)staining,alizarin red staining and qRT-PCR were used to detect osteogenic gene expression of the cells.Results:A coating of PDA particles was observed on the surface of D/PCL film.FTIR and XPS showed that the characteristic peaks of Gel and PDA,and there was no obvious droplets on the surface of G/PCL and D/PCL ob-served by contact angle test.Cell density of G/PCL group was higher,the adhesion morphology was good and pseudopods were obvi-ous.CCK-8 assay showed the highest proliferation of the cells on G/PCL(P＜0.05).ALP and alizarin red staining of the cells were stronger in D/PCL group than in the other 2 groups.qRT-PCR results showed that the mRNA expression of ALP,COL-1,RUNX2 and OCN was higher in the D/PCL group than in the other 2 groups.Conclusion:Both Gel and PDA modification can enhance the cell adhesion,proliferation and osteogenic properties of PCL scaffolds,Gel modification may induce a more pronounced proliferative effect and PDA modification more pronounced osteogenic effect.