A P value <0.05

was considered to indicate a significant difference. Results and discussions Synthesis and characterization of Lenvatinib mouse PLA-PCL-TPGS random copolymer. The structure of the synthesized PLA-PCL-TPGS copolymer was detected by 1H NMR in CDCl3. Figure 1 shows the chemical structure of PLA-PCL-TPGS random copolymer and 1H NMR spectroscopy of the PLA-PCL-TPGS copolymer. The signals at 5.2 and 1.69 ppm (peaks a and e) were assigned to the CH protons and methyl protons -CH3 of PLA segment, respectively. The peak at 3.65 ppm (peak c) was assigned to the -CH2 protons of PEO part of Q-VD-Oph ic50 TPGS. The lower peaks in the aliphatic region belong to various moieties of vitamin E tails. The peaks at 4.06 (peak b), 2.31 (peak d), 1.60 to 1.70 (peak e), and 1.35 to 1.43 (peak f) were assigned to -OCH2, -COCH2, -CH2 (4 H), and -CH2 (2 H) segments of PCL, Fosbretabulin clinical trial respectively [24]. The molecular weight of the PLA-PCL-TPGS was calculated using the ratio between the peak areas at 4.06 (peak area 9.64), 5.2 (peak area 1.23), and 3.65 (peak area 3.00). The number-averaged molecular weight of the PLA-PCL-TPGS random copolymer was determined to be 33,229. The feeding ratios of ε-caprolactone, lactide, and TPGS molecular mass were 75%, 15%, and 10%, respectively. However, the ratios of ε-caprolactone, lactide, and TPGS molecular mass

which were integrated into the PLA-PCL-TPGS copolymers were 87.18%, 8.17%, and 4.64%. Characterization of nanoparticles Size, zeta potential, and encapsulation efficiency The particle size data of the 5% thiolated chitosan-modified PCL nanoparticles (CNP), unmodified PLA-PCL-TPGS nanoparticles (UNP), 5% thiolated chitosan-modified PLA-PCL-TPGS nanoparticles (TNP), and 20% thiolated chitosan-modified PLA-PCL-TPGS nanoparticles (DNP) fabricated in this new research are presented in Table 1. The particle size was found to be an important parameter regarding particle uptake. The small nanoparticle size may provide a large surface area and increase in mucin adsorption, which leads to a high mucoadhesive property

for the nanoparticles [34]. The permeability of the particles through the intestinal mucosa decreases with increasing particle size reaching a cut-off at around 500 nm [35, 36]. The average diameter of the resulted nanoparticles was around 200 nm, which is in the size range favoring the intestinal uptake of the nanoparticles [2, 8]. The results also showed that the addition of thiolated chitosan resulted in a slight increase in particle size. Zeta potential analysis confirmed that surface modification with 5% thiolated chitosan reversed the PLA-PCL-TPGS nanoparticles from a negative surface charge of −18.29 mV to a significantly positive charge of +24.66 mV. As reported in the literature, positive surface charge could enhance the mucosal uptake due to anionic nature of mucous layer [37].