Dataset Information

Ahmed implant coated with poly(2-methacryloyloxyethyl phosphorylcholine) inhibits foreign body reactions in rabbit eyes.

ABSTRACT:

Purpose

Wound healing after Ahmed glaucoma valve (AGV) implantation often entails fibrosis as a foreign body reaction to the silicone plate. Poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) forms an antifouling surface that inhibits fibrosis during wound healing. In this study, we aimed to compare the effects of the implantation of AGV coated with PMPC (wPMPC) versus AGV without PMPC (woPMPC) in rabbits.

Methods

Six New Zealand White rabbit does underwent AGV implantation in both eyes. For each rabbit, one eye was randomly selected for implantation of AGV wPMPC and a conventional AGV (woPMPC) was implanted in the contralateral eye. Gross conjunctival vascularity was compared between the two groups at the first, second, and fourth weeks after surgery. The eyes were enucleated in four weeks and subjected to staining with hematoxylin and eosin and Masson's trichrome stain. The fibrosis and inflammation status among the eye samples were compared by measuring the thickness of the fibrotic walls and counting the number of chronic inflammatory cells around the AGV. Counting of inflammatory cells and measuring fibrotic wall thickness were done in a blinded method to eliminate observer bias. Statistical analysis was performed using the Mann-Whitney U test.

Results

Gross and histological examinations revealed no toxic effects of PMPC. There were no apparent differences in overall conjunctival vascularity between the two groups at weeks 1, 2, and 4 after surgery. The average inflammatory cell counts were 14.3 ± 5.8 per slide and 27.3 ± 8.6 per slide in the wPMPC and woPMPC groups, respectively (p = 0.037). The average thicknesses of the fibrotic wall were 57.9 ± 11.3 μm and 81.5 ± 21.3 μm in the wPMPC and woPMPC groups, respectively (p = 0.025).

Conclusion

Compared to the woPMPC group, the number of inflammatory cells and fibrosis were significantly decreased in the wPMPC group.

SUBMITTER: Kee HJ

PROVIDER: S-EPMC8162657 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Nowadays, using polymers with specific characteristics to coat the surface of a device to prevent undesired biological responses can represent an optimal strategy for developing new and more efficient implants for biomedical applications. Among them, zwitterionic phosphorylcholine-based polymers are of interest due to their properties to resist cell and bacterial adhesion. In this work, the Matrix-Assisted Laser Evaporation (MAPLE) technique was investigated as a new approach for functionalising Polydimethylsiloxane (PDMS) surfaces with zwitterionic poly(2-Methacryloyloxyethyl-Phosphorylcholine) (pMPC) polymer. Evaluation of the physical-chemical properties of the new coatings revealed that the technique proposed has the advantage of achieving uniform and homogeneous stable moderate hydrophilic pMPC thin layers onto hydrophobic PDMS without any pre-treatment, therefore avoiding the major disadvantage of hydrophobicity recovery. The capacity of modified PDMS surfaces to reduce bacterial adhesion and biofilm formation was tested for Gram-positive bacteria, Staphylococcus aureus (S. aureus), and Gram-negative bacteria, Escherichia coli (E. coli). Cell adhesion, proliferation and morphology of human THP-1 differentiated macrophages and human normal CCD-1070Sk fibroblasts on the different surfaces were also assessed. Biological in vitro investigation revealed a significantly reduced adherence on PDMS-pMPC of both E. coli (from 29 × 10 6 to 3 × 102 CFU/mL) and S. aureus (from 29 × 106 to 3 × 102 CFU/mL) bacterial strains. Additionally, coated surfaces induced a significant inhibition of biofilm formation, an effect observed mainly for E. coli. Moreover, the pMPC coatings improved the capacity of PDMS to reduce the adhesion and proliferation of human macrophages by 50% and of human fibroblast by 40% compared to unmodified scaffold, circumventing undesired cell responses such as inflammation and fibrosis. All these highlighted the potential for the new PDMS-pMPC interfaces obtained by MAPLE to be used in the biomedical field to design new PDMS-based implants exhibiting long-term hydrophilic profile stability and better mitigating foreign body response and microbial infection.