title: Histological reaction of sintered nanohydroxyapatite-coated cuff and its fibroblast-like cell hybrid for an indwelling catheter.
abstract: Rapid tissue-ingrowth of a sintered hydroxyapatite(HAp)-coated and cell-hybrid subcutaneous cuff equipped with an indwelling catheter was developed. The rod-like HAp nanoparticles were coated by covalent bonding on the surface of the silk fibroin (SF) fibers for about 100 microm of the length. The fibers were transplanted three-dimensionally on a cuff substrate made of silicone elastomer with an adhesive. The fibroblast-like cells, explanted and proliferated from skin tissue containing the epidermis, dermis, and subcutaneous tissue of Japanese white rabbits, were incubated on the three-dimensional cuff for three days. Three types of cuff--polyester, HAp-coated, and cell-hybrid cuffs--were percutaneously implanted into the backs of the same animals for 3 and 7 days. The subcutaneous tissues around the cuffs were stained with hematoxylin-eosin. Immunohistochemical staining to identify macrophages and alpha-smooth muscle actin (alpha-SMA) was also done and examined by light microscopy. The alpha-SMA-positive area was very limited in the polyester cuff group even after 7 days, although many macrophages infiltrated into the fibers. In the cell-hybrid cuff group, on the other hand, an alpha-SMA-positive area was formed extensively after 3 and 7 days, causing severe inflammation. In the HAp-coated cuff group, an alpha-SMA-positive area was formed among the fibers with little inflammation. The extent order of the alpha-SMA-positive area was cell-hybrid cuff >> HAp-coated cuff >> polyester cuff, while the degree of inflammatory cells order was cell-hybrid cuff >> polyester cuff >> HAp-coated cuff.
authors.affiliation: Department of Biomedical Engineering, Advanced Medical Engineering Center, National Cardiovascular Center Research Institute, Suita, Osaka, Japan. furuzono@ri.ncvc.go.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Furuzono
authors.forename: Mitsuki
authors.initials: M
authors.lastname: Ueki
authors.forename: Harumi
authors.initials: H
authors.lastname: Kitamura
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Oka
authors.forename: Enyu
authors.initials: E
authors.lastname: Imai