Construction of cell-compatible layer and culture of human umbilical vascular endothelial cells on porous polystyrene membranes

Medical Applications of Porous Biomaterials: Features of Porosity and Tissue-Specific Implications for Biocompatibility

Porosity is an important material feature commonly employed in implants and tissue scaffolds. The presence of material voids permits the infiltration of cells, mechanical compliance, and outward diffusion of pharmaceutical agents. Various studies have confirmed that porosity indeed promotes favorable tissue responses, including minimal fibrous encapsulation during the foreign body reaction (FBR). However, increased biofilm formation and calcification is also described to arise due to biomaterial porosity. Additionally, the relevance of host responses like the FBR, infection, calcification, and thrombosis are dependent on tissue location and specific tissue microenvironment. In this review, the features of porous materials and the implications of porosity in the context of medical devices is discussed. Common methods to create porous materials are also discussed, as well as the parameters that are used to tune pore features. Responses toward porous biomaterials are also reviewed, including the various stages of the FBR, hemocompatibility, biofilm formation, and calcification. Finally, these host responses are considered in tissue specific locations including the subcutis, bone, cardiovascular system, brain, eye, and female reproductive tract. The effects of porosity across the various tissues of the body is highlighted and the need to consider the tissue context when engineering biomaterials is emphasized.

Photografting of poly(hydroxylethyl acrylate) onto porous polyurethane scaffolds to improve their endothelial cell compatibility

In order to improve the cytocompatibility of polyurethane (PU) porous scaffolds obtained by thermally-induced phase separation, poly(hydroxylethyl acrylate) (PHEA) was covalently immobilized by grafting copolymerization of HEA by photo-oxidation of the scaffolds and initiation of UV light. FT-IR-ATR spectroscopy and X-ray photoelectron spectroscopy (XPS) characterizations confirmed the occurrence of the grafting co-polymerization of HEA on the porous PU scaffolds. The measurement of water absorption demonstrated the improvement of the hydrophilicity after grafting with PHEA. The results obtained in a human umbilical vein endothelial cell (HUVEC) culture proved that the porous PU scaffold modified with the hydrophilic PHEA had better cytocompatibility than the control. The influence of surface pore size on the HUVEC growth behavior was assessed regarding cell anchorage, proliferation and viability, as well as morphology. An overall increase of cell number and viability with the decrease of the surface pore size was found.

Endothelial cells grown on thin polyelectrolyte mutlilayered films: an evaluation of a new versatile surface modification

Endothelial cell seeding constitutes an appreciated method to improve blood compatibility of small-diameter vascular grafts. In this study, we report the development of a simple innovative technique based on multilayered polyelectrolyte films as cell adhesive substrates. Polyelectrolyte multilayered films ending by poly(sodium-4-styrenesulfonate)/poly(allylamine hydrochloride) (PSS/PAH) or poly(L-glutamic acid)/poly(D-lysine) (PGA/PDL) could enhance cell adhesion by modification of the physico-chemical properties of the surface. The biological responses of human umbilical vein endothelial cells seeded on the polyelectrolyte multilayer films, on PDL or PAH monolayers, and on control surfaces, were evaluated in terms of initial attachment, growth, cellular metabolic activity, endothelial phenotype, and adhesion. The results showed that polyelectrolyte multilayers neither induce cytotoxic effects nor alter the phenotype of the endothelial cells. The polyelectrolyte multilayered films enhanced initial cell attachment as compared to the polyelectrolyte monolayer. Cell growth observed on the films was similar to that on TCPS. Among the different coating tested, the film ending by PSS/PAH exhibited an excellent cellular biocompatibility and appeared to be the most interesting surface in terms of cellular adhesion and growth. Such films could be used to cover hydrophobic (cell resistant) substrates in order to promote cell colonization, thereby constituting an excellent material for endothelial cell seeding.