The chemical structure of TPGS-b-(PCL-ran-PGA) copolymer is shown in Figure 2A. In order to further confirm the formation AZD1152 research buy of the random copolymer, the 1H NMR spectrum is recorded and is shown in Figure 2B. The peak at
3.65 ppm (Figure 2, peak e) could be attributed to the -CH2 protons of the PEO part of TPGS [2, 41]. The lower signals in the aliphatic zone belong to various moieties of vitamin E tails [2, 41]. Peaks at 1.39 (h), 1.67 (g), 2.31 to 2.44 (f), and 4.06 ppm (d) are assigned to methylene protons in PCL units, respectively [2, 41]. The difference between the two peaks at 4.06 (c) and 4.16 ppm (b) which indicated that two kinds of copolymers would be obtained was reasonable (shown in Figure 2). Furthermore, it was from the appearance of the two different peaks that we could conclude that both GA ICG-001 and CL monomers had copolymerized with TPGS monomers. The characteristic signal at 4.62 to 4.82 ppm (a) exists, which is attributed to the
methylene (CH2) protons of the PGA units . The molecular selleck chemical weight of the TPGS-b-(PCL-ran-PGA) copolymer was calculated by the use of the ratio between the peak areas at 4.06, 4.62 to 4.82, and 3.65 ppm. The Mn of the TPGS-b-(PCL-ran-PGA) copolymer was estimated to be 23,852. The Mn calculated from the gel permeation chromatograph was 25,811. It seemed that the molecular weight measured from NMR and GPC can confirm each other. Figure 1 FT-IR spectra of TPGS and TPGS- b -(PCL- ran -PGA) copolymer. Figure 2 Chemical structure (A) and typical 1 H NMR spectra (B) of TPGS- b -(PCL- ran -PGA) copolymer. Construction and expression of pShuttle2-TRAIL and pShuttle2-endostatin Recombinant plasmids pShuttle2-TRAIL and pShuttle2-endostatin were verified by enzyme digestion and DNA sequencing. Protein expression of TRAIL and endostatin was analyzed not by Western blot using cell lysate after transfection of HeLa cells using PEI (Figure 3). These results showed that pShuttle2-TRAIL and pShuttle2-endostatin were successfully constructed
and expressed in HeLa cells. Figure 3 Western blot analysis of recombined pShuttle2-endostatin and pShuttle2-TRAIL expression in 293 T cells. Control: 293 T cells transfected by pShuttle2. rE: 293 T cells transfected by pShuttle2-endostatin. rT: 293 T cells transfected by pShuttle2-TRAIL. Characterization of nanoparticles The effect of PEI modification on particle size was determined by dynamic light scattering (DLS; Table 1). The average hydrodynamic diameter of the polyplexed PEI/pDNA nanoparticles (CNP) was 83 nm, whereas the diameters of the unmodified TPGS-b-(PCL-ran-PGA) nanoparticles (DNP) and PEI-modified TPGS-b-(PCL-ran-PGA) nanoparticles (HNP) were approximately 215 and approximately 273 nm, respectively (Figure 4A). In addition, the surface charge (zeta potential) of the nanoparticles was determined by laser Doppler anemometry (Zetasizer Nano ZS90, Malvern Instruments, Malvern, UK; Table 1 and Figure 4B).