https://orcid.org/0000-0002-1666-4253
Figures & data
Figure 1. Adherence of MPC polymer to cultured cells.
Adherence of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer to Detroit 562 cells was measured by fluorescence-activated cell sorting (FACS) (a) and micrographs (b). Cells treated with phosphate-buffered saline (PBS) were used as the control. Compared with controls, the adherence of MPC polymer to the cells increased with increasing concentrations of MPC polymer of 0.1%, 0.5%, and 3.5%. FITC-A, fluoresce in isothiocyanate A.
Figure 2. Effects of MPC polymer concentration on the adherence of Spn and NTHi in vitro.
Five strains of Streptococcus pneumoniae (Spn) and nontypeable Haemophilus influenzae (NTHi) were investigated, and cells treated with phosphate-buffered saline (PBS) were used as a control. The number of adherent bacteria was determined. When treated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, adherence of both Spn and NTHi was significantly suppressed at 3.5% and 0.5% MPC polymer concentration compared with the control, but bacterial adherence was not suppressed at 0.1% MPC polymer concentration (*p < 0.05). CFU, colony-forming units.
Figure 3. Effects of MPC polymer and PC-KLH on the adherence of Spn and NTHi in vitro.
The relationship between bacterial phosphorylcholine (PC) expression and the number of adhering bacteria when cells were treated with PC-key hole limpet hemocyanin (PC-KLH) or 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer is shown. (a:Streptococcus pneumoniae [Spn], n = 21; b: nontypeable Haemophilus influenzae [NTHi], n = 21.) When cells were treated with MPC polymer for both Spn and NTHi, the number of adhering bacteria was similar regardless of the level of PC expression. The cells were treated with MPC polymer or PC-KLH (c and d). Cells treated with phosphate-buffered saline (PBS) were used as the control. Bacterial adherence was significantly suppressed when bacteria were treated with MPC polymer and PC-KLH compared with the control in the PC-high groups but not in the PC-low groups (*p < 0.05). N.S., not significant; CFU, colony-forming units; MFI, mean fluorescence intensity.
Figure 4. Effects of MPC polymerconcentration on the adherence of Spn and NTHi in vivo.
The number of adhering bacteria when the mouse nasal cavity was treated with phosphate-buffered saline (PBS) was used as the control. When treated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, bacterial adherence was significantly suppressed at ≤0.5% for Streptococcus pneumoniae (Spn) and at ≤0.5% for nontypeable Haemophilus influenzae (NTHi) compared with control (*p < 0.05). CFU, colony-forming units.
Figure 5. MPC polymer adherence time in vivo.
Streptococcus pneumoniae was administered into the nasal cavity of BALB/c mice as a control, and the mean number of bacteria adhering at the indicated times (2, 4, 8, 12, and 24 h after administration) was determined (n = 5). When the nasal cavities of the mice were treated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, bacterial adherence was significantly suppressed for 2 to 24 h there after. The number of adhering bacteria was lowest after 12 h (*p < 0.05). CFU, colony-forming units.
Figure 6. Effects of MPC polymer and PC-KLH on the adherence of Spn and NTHi in vivo.
The relationship between bacterial phosphorylcholine (PC) expression and the number of adhering bacteria when cells were treated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer and PC-keyhole limpet hemocyanin (PC-KLH) is shown. (a:Streptococcus pneumoniae [Spn], n = 21, and b: nontypeable Haemophilus influenzae [NTHi], n = 21.) When cells were treated with MPCpolymer for both Spn and NTHi, the number of adhering bacteria was similar, regardless of the level of PC expression. The cells were treated with MPC polymer and PC-KLH (c and d). Cells that were treated with phosphate-buffered saline (PBS) were used as the control. Bacterial adherence was significantly suppressed when treated with MPC polymer and PC-KLH compared with the control in PC-high groups but not in PC-low groups (*p < 0.05). N.S., not significant; CFU, colony-forming units; MFI, mean fluorescence intensity.
Figure 7. Effect of MPC polymer on nasal mucosa cells.
The effect of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer on the mucous membrane of BALB/c mice following administration into the nasal cavity was examined. Phosphate-buffered saline (PBS) administration was used as a control and compared with the administration of 0.5% MPC polymer. The thickness of the mucosa at the upper end of the nasal septal cartilage was measured and averaged. Three mice were used for each group. No change in mucosa thickness was observed after treatment with 0.5% MPC polymer compared with control (upper). When MPC polymer was administered, the cellular structure of the mucosa remained histologically unchanged. N.S., not significant.
Data availability statement
The authors confirm that the data supporting the findings of this study are available within the article.