Jones Julian - Bio-Glasses

Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Erlangen, Germany

Otto Schott Institute, Friedrich Schiller University Jena, Jena, Germany

Department of Materials Engineering, Monash University, Clayton, Victoria, Australia

Kazuo Inamori School of Engineering, New York State College of Ceramics, Alfred University, Alfred, USA

Kazuo Inamori School of Engineering, New York State College of Ceramics, Alfred University, Alfred, USA

Center for Bone and Tissue Repair, Graduate Center for Materials Research, Materials Science and Engineering Department, Missouri University of Science and Technology, Rolla, Missouri, USA

Department of Bioscience and Biotechnology, Okayama University, Tsushima, Okayama, Japan

Ivoclar Vivadent AG, Schaan, Principality of Liechtenstein

Process Chemistry Centre, bo Akademi University, Biskopsgatan, bo, Finland

Department of Materials, Imperial College London, South Kensington Campus, London, UK

MO-SCI Corporation, HyPoint North, Rolla, Missouri, USA

Department of Materials, Imperial College London, South Kensington

Campus, London, UK

Department of Bioscience and Biotechnology, Okayama University, Tsushima, Okayama, Japan

Department of Bioscience and Biotechnology, Okayama University, Tsushima, Okayama, Japan

Department of Biomaterials, Kyushu University, Maidashi, Higashi, Fukuoka, Japan

Department of Applied Science and Technology, Politecnico di Torino, Torino, Italy

Institute of Dentistry, Faculty of Medicine, University of Turku, Turku, Finland

Foreword

Hamburger. Hot Dog. Ice Cream. Five ordinary words, but each had extraordinary significance. It was 1984 when Dr. Gerry Merwin, MD, an Ear, Nose and Throat surgeon at the University of Florida, Gainesville, Florida, whispered the words into the ear of a patient. She was an extraordinary patienta young mother, expectant with her second child. She was desperate to be able to hear her new-born baby cry. However, the mother was deaf from an infection that had dissolved two of the three bones of her middle ear. Only part of the stapes (stirrup) remained. Under a local anaesthetic, Dr. Merwin had just implanted the world's first Bioglass device into her middle ear. The implant was designed to conduct sound waves from her eardrum to her inner ear, the cochlea, and thus restore her hearing.

Bioglass was the first man-made material to bond to living tissues. I discovered it in 1969, but the material had to pass 15 years of in vitro (cells growing on it in the laboratory) and in vivo (animal) tests before the first device could be implanted. The University of Florida Shands Hospital Ethics Committee had approved the first human trial after evaluating data from safety tests done on hundreds of mice by Dr. Merwin, his surgical residents and Dr. June Wilson, who interpreted the histology data.

But, the big questions remained: Would this new material work in a human? Would the implant bond to the soft connective tissue of the eardrum? Would it bond to the hard connective tissue (bone) of the stapes? Would it conduct sound? Would normal hearing be restored?

No one knew the answers to these questions. Ear surgeons had inserted other types of middle ear implants in patients for many years, but they often failed. The materials used were metals and plastics, selected because they were as inert and non-toxic as possible in the body. A thin layer of scar tissue formed around the metal and plastic parts, isolating them from the body, eventually causing the implant to be forced out of position. All of the first-generation biomedical materials used in the body (so-called bio-inert materials) led to the formation of scar tissue. For some clinical needs, the scar tissue poses no problem. For a middle ear implant, scar tissue can be disastrous. Continual vibration and motion of the implant can wear a hole in the eardrum. The implant can come out through the hole, permanently damaging the eardrum.