title: A review of biocompatibility in hernia repair; considerations in vitro and in vivo for selecting the most appropriate repair material.
abstract: OBJECTIVE
  Repair of hernia typically makes use of a prosthetic material; synthetic or biologic in nature. Any material which enters the body is subject to interrogation by the inflammation and immune system in addition to numerous other cell families, the outcome of which ultimately determines the success of the repair. In this review, we discuss the fundamental biology which occurs in situ when a biomaterial associates with a tissue, compare and contrast the techniques available to predict this in vitro, and review how features of hernia repair materials specifically may manipulate tissue interrogation and integration. Finally, we conclude our article by examining how biocompatibility impacts surgical practise and how a better understanding of the manner by which materials and tissues interact could benefit hernia repair.
  
  
  METHODS
  A review of the literature was conducted using appropriate scientific search engines in addition to inclusion of findings from the groups' primary research.
  
  
  RESULTS
  Using pre-clinical assays to anticipate the biocompatibility of a medical device is critical; however, to maximise the scientific power of in vitro findings, we must carefully consider the in vivo niche of the cells with which we are working. Excessive in vitro culture or contact to non-self materials can add compounding complexity to studies involving leucocytes for instance; therefore, we must ensure careful and stringent assay design when developing techniques for assaying pre-clinical biocompatibility. Furthermore, many of the features associated with hernia repair material design specifically, included to enhance their mechanical or biodegradation characteristics, are inadvertently instructive to cells, and therefore, throughout the prototype stages of a materials development, regular biocompatibility assessment must be performed.
  
  
  CONCLUSIONS
  The biocompatibility of a material is rate limiting in its ability to function as a medical device. The future of hernia repair materials will rely on close cohesion between the surgical and scientific communities to ensure the most robust biocompatibility assessment techniques, and models are utilised to predict the efficacy of a given material in a particular surgical application.
authors.affiliation: Clinical Engineering (UKCTE), Institute of Ageing and Chronic Disease, Duncan Building Ground Floor, Daulby Street, Liverpool, L69 3GA, UK, n.bryan@liv.ac.uk.
authors.forename: N
authors.initials: N
authors.lastname: Bryan
authors.forename: C
authors.initials: C
authors.lastname: Battersby
authors.forename: N
authors.initials: N
authors.lastname: Smart
authors.forename: J
authors.initials: J
authors.lastname: Hunt
mesh_terms: D001672:Biocompatible Materials; D006547:Hernia / Q000503:physiopathology*; D059685:Herniorrhaphy; D006801:Humans; D066298:In Vitro Techniques; D007962:Leukocytes / Q000502:physiology*; D013526:Surgical Mesh; D014945:Wound Healing / Q000502:physiology*
chemical_list: D001672:Biocompatible Materials