Research for new biocompatible and easily implantable materials continuously
proposes new molecules and new substances with biological, chemical and physical
characteristics, that are more and more adapted to aesthetic and reconstructive
surgery and to the development of biomedical devices such as cardiovascular
prostheses.
Two classes of polymeric biomaterials seem to meet better these requirements:
“hydrogels” , which includes polyalkylimide (PAI) and polyvinylalcohol (PVA) and
“elastomers”, which includes polyurethanes (PUs). The first ones in the last decade
have had a great application for soft tissue augmentation, due to their similarity to
this tissue for their high water content, elasticity and oxygen permeability (Dini et
al., 2005). The second ones, on the contrary, are widely used in cardiovascular
applications (catheters, vascular grafts, ventricular assist devices, total artificial
hearts) due to their good mechanical properties and hemocompatibility (Zdrahala
R.J. and Zdrahala I.J., 1999).
In the biocompatibility evaluation of these synthetic polymers, that is important for
its potential use in clinical applications, a fundamental aspect is the knowledge of the
polymers cytotoxicity and the effect of their interaction with cells, in particular with
the cell populations involved in the inflammatory responses, i.e.
monocyte/macrophages.
In consideration of what above said, the aim of this study is the comprehension of
the in vitro effect of PAI, PVA and PU on three cell lines that represent three
different stages of macrophagic differentiation: U937 pro-monocytes, THP-1
monocytes and RAW 264.7 macrophages.
Cytotoxicity was evaluated by measuring the rate of viability with MTT, Neutral Red
and morphological analysis at light microscope in time-course dependent
experiments.
The influence of these polymers on monocyte/macrophage activation in terms of
cells adhesion, monocyte differentiation in macrophages, antigens distribution,
aspecific phagocytosis, fluid-phase endocitosis, pro-inflammatory cytokine (TNF-α,
IL-1β, IL-6) and nitric oxide (NO) release was evaluated.
In conclusion, our studies have indicated that the three different polymeric
biomaterials are highly biocompatible, since they scarcely affected viability of U937,
THP-1 and RAW 264.7 cells. Moreover, we have found that even though hydrogels
and polyurethane influences monocyte/macrophage differentiation (depending on the
particular type of cell and polymer), they are immunocompatible since they not
induced significantly high cytokine release. For these reasons their clinical
applications are strongly encouraged.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:698 |
| Date | 23 May 2008 |
| Creators | Scordari, Alessandra <1980> |
| Contributors | Marini, Marina |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | Italian |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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