To explore the efficacy of photodynamic nanocarriers combined with si-P3H4 in the precise treatment of bladder tumors.

RT-qPCR and Western Blot were used to detect the expression of P3H4 mRNA and protein in EJ and T24 cell lines of bladder cancer after siRNA transfection. CCK8, scratch test and Transwell chamber were used to detect the effect of P3H4 knockdown on proliferation, migration and invasion of EJ and T24 bladder cancer cells. The polymer nanocarrier CH3-R9-cRGD was synthesized with amino resin as substrate, and the drug encapsulated si-P3H4 and photosensitizer Ce6 were transfected into bladder cancer cells (HCV29 cells) to detect the drug release in vitro under different pH and laser irradiation conditions. At the same time, the mechanism of targeted binding endocytosis of nano drugs and bladder cancer cells was explored, and the level of intracellular reactive oxygen species (ROS) was detected. Different groups of nanocomposites were transfected into bladder cancer cells, and the cell viability of each group was detected by CCK8 method. In vivo experiments were conducted to further explore of the tumor inhibitory ability of different groups of nanocomposites.

The P3H4mRNA expression levels in the EJ group and T24 group decreased to 68.4% and 57.1% of the control group, respectively, according to RT qPCR. Western blot showed that the expression of P3H4 protein in the EJ and T24 groups decreased to 20.3% and 36.5%, respectively, compared to the negative control group. The absorbance A value of CCK8 experiment was (0.785 ± 0.084) vs (1.358 ± 0.064) in the EJ group compared to the control group at 96 hours, t=12.06, P<0.01; Compared to the control group at 96 hours, the T24 group showed (0.833 ± 0.065) vs (1.346 ± 0.545), t=13.415, P<0.01. The cell healing rate in the scratch experiment was (47.8 ± 4.32)% in the EJ group compared to the control group, (68.60 ± 4.39)%, t=7.545, P<0.01; The T24 group compared to the control group was (50.40 ± 3.64)% vs (70.61 ± 3.85)%, t=8.521, P<0.01. Transwell cell penetration count: The EJ group had [(302.71±7.56) vs (130.42±3.95)] compared to the control group; t=53.40, P<0.01; T24 group [(99.56±4.50) vs (35.22±6.28)], t=24.974, P<0.01. The imaging results showed that the peptide nanocarrier had good permeability and could target si-P3H4 and Ce6 into bladder cancer cells at the same time. The CCK8 method detection results showed that when the concentration of the nanocomposite CH3-R9-cRGD&Ce6 is 50 μ At g/mL, the cell viability of the laser irradiated group was lower than that of the non laser irradiated group, and the cell viability of the nanoprobe+laser+siP3H4 group was the lowest (F=299.57, P<0.05). In vivo experiments had shown that nanocomposites/si-P3H4/laser have the most significant inhibitory effect on tumor cell enhancement.

Nanocarriers can simultaneously target si-P3H4 and Ce6 into bladder cancer cells to inhibit cell proliferation and achieve comprehensive treatment of bladder cancer. Photodynamics and gene therapy have complementary advantages in the field of bladder cancer treatment. The combination of the two can achieve synergistic enhancement of tumor treatment and can be applied to the treatment of bladder urothelial carcinoma.