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Host inflammatory response to polypropylene implants: insights from a quantitative immunohistochemical and birefringence analysis in a rat subcutaneous model.

Prudente A, Favaro WJ, Latuf P, Riccetto CL - Int Braz J Urol (2016 May-Jun)

Bottom Line: After 30 days, a reduction of IL-1 (p=0.010) and TNF (p=0.016) for PP and of IL-1 (p=0.010) for sham were observed.Moreover, area of MMP-2 immunoreactivity decreased over time for PP group (p=0.018).The implantation of monofilament and macroporous polypropylene in the subcutaneous of rats resulted in increased inflammatory activity and higher TNF production in the early post implant phase.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Ciências Médicas da Universidade de Campinas, Campinas, SP, Brasil.

ABSTRACT

Objectives: To describe acute and sub acute aspects of histological and immunohistochemical response to PP implant in a rat subcutaneous model based on objective methods.

Materials and methods: Thirty rats had a PP mesh subcutaneously implanted and the same dissection on the other side of abdomen but without mesh (sham). The animals were euthanized after 4 and 30 days. Six slides were prepared using the tissue removed: one stained with hematoxylin-eosin (inflammation assessment); one unstained (birefringence evaluation) and four slides for immunohistochemical processing: IL-1 and TNF-α (pro-inflammatory cytokines), MMP-2 (collagen metabolism) and CD-31 (angiogenesis). The area of inflammation, the birefringence index, the area of immunoreactivity and the number of vessels were objectively measured.

Results: A larger area of inflammatory reaction was observed in PP compared to sham on the 4th and on the 30th day (p=0.0002). After 4 days, PP presented higher TNF (p=0.0001) immunoreactivity than sham and no differences were observed in MMP-2 (p=0.06) and IL-1 (p=0.08). After 30 days, a reduction of IL-1 (p=0.010) and TNF (p=0.016) for PP and of IL-1 (p=0.010) for sham were observed. Moreover, area of MMP-2 immunoreactivity decreased over time for PP group (p=0.018). Birefringence index and vessel counting showed no differences between PP and sham (p=0.27 and p=0.58, respectively).

Conclusions: The implantation of monofilament and macroporous polypropylene in the subcutaneous of rats resulted in increased inflammatory activity and higher TNF production in the early post implant phase. After 30 days, PP has similar cytokines immunoreactivity, vessel density and extracellular matrix organization.

No MeSH data available.


Related in: MedlinePlus

Evaluation of collagen fibers birefringence in polarization microscopy. (A) The collagen fibers bright on the dark background. (B) The same area after 45o rotation of the polarization microscope stage. White arrow indicates the same fiber package in opposite arrangement (200x).
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f02: Evaluation of collagen fibers birefringence in polarization microscopy. (A) The collagen fibers bright on the dark background. (B) The same area after 45o rotation of the polarization microscope stage. White arrow indicates the same fiber package in opposite arrangement (200x).

Mentions: The analysis of the direction and packing of collagen fibers was performed by polarizing microscopy, but only for those animals euthanized at 30 days due to the time necessary for the growth of the host collagen fibers. In each selected image (200x magnification), two records were obtained by rotating the microscope stage at approximately 45º in each field, to obtain the maximum polarization effect (called positions A and B), in order to demonstrate the group of fibers with the same or opposite orientation (Figure-2).


Host inflammatory response to polypropylene implants: insights from a quantitative immunohistochemical and birefringence analysis in a rat subcutaneous model.

Prudente A, Favaro WJ, Latuf P, Riccetto CL - Int Braz J Urol (2016 May-Jun)

Evaluation of collagen fibers birefringence in polarization microscopy. (A) The collagen fibers bright on the dark background. (B) The same area after 45o rotation of the polarization microscope stage. White arrow indicates the same fiber package in opposite arrangement (200x).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920579&req=5

f02: Evaluation of collagen fibers birefringence in polarization microscopy. (A) The collagen fibers bright on the dark background. (B) The same area after 45o rotation of the polarization microscope stage. White arrow indicates the same fiber package in opposite arrangement (200x).
Mentions: The analysis of the direction and packing of collagen fibers was performed by polarizing microscopy, but only for those animals euthanized at 30 days due to the time necessary for the growth of the host collagen fibers. In each selected image (200x magnification), two records were obtained by rotating the microscope stage at approximately 45º in each field, to obtain the maximum polarization effect (called positions A and B), in order to demonstrate the group of fibers with the same or opposite orientation (Figure-2).

Bottom Line: After 30 days, a reduction of IL-1 (p=0.010) and TNF (p=0.016) for PP and of IL-1 (p=0.010) for sham were observed.Moreover, area of MMP-2 immunoreactivity decreased over time for PP group (p=0.018).The implantation of monofilament and macroporous polypropylene in the subcutaneous of rats resulted in increased inflammatory activity and higher TNF production in the early post implant phase.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Ciências Médicas da Universidade de Campinas, Campinas, SP, Brasil.

ABSTRACT

Objectives: To describe acute and sub acute aspects of histological and immunohistochemical response to PP implant in a rat subcutaneous model based on objective methods.

Materials and methods: Thirty rats had a PP mesh subcutaneously implanted and the same dissection on the other side of abdomen but without mesh (sham). The animals were euthanized after 4 and 30 days. Six slides were prepared using the tissue removed: one stained with hematoxylin-eosin (inflammation assessment); one unstained (birefringence evaluation) and four slides for immunohistochemical processing: IL-1 and TNF-α (pro-inflammatory cytokines), MMP-2 (collagen metabolism) and CD-31 (angiogenesis). The area of inflammation, the birefringence index, the area of immunoreactivity and the number of vessels were objectively measured.

Results: A larger area of inflammatory reaction was observed in PP compared to sham on the 4th and on the 30th day (p=0.0002). After 4 days, PP presented higher TNF (p=0.0001) immunoreactivity than sham and no differences were observed in MMP-2 (p=0.06) and IL-1 (p=0.08). After 30 days, a reduction of IL-1 (p=0.010) and TNF (p=0.016) for PP and of IL-1 (p=0.010) for sham were observed. Moreover, area of MMP-2 immunoreactivity decreased over time for PP group (p=0.018). Birefringence index and vessel counting showed no differences between PP and sham (p=0.27 and p=0.58, respectively).

Conclusions: The implantation of monofilament and macroporous polypropylene in the subcutaneous of rats resulted in increased inflammatory activity and higher TNF production in the early post implant phase. After 30 days, PP has similar cytokines immunoreactivity, vessel density and extracellular matrix organization.

No MeSH data available.


Related in: MedlinePlus