Date/Time
Date(s) - 10/27/2020
3:00 pm - 4:00 pm
Categories
Aldo Boccaccini, Ph.D.
Professor of Biomaterials, Head of The Institute of Biomaterials
University of Erlangen-Nuremberg, Germany
Abstract:
Bioactive glass (BG) was discovered by the late Prof. Larry L. Hench at University of Florida 50 years ago [1]. The “traditional” applications of BG have been as a material for bone replacement, for example as bone defect filler, small bone and dental implants and coatings for orthopedic applications. More recently, BGs have started to be highly considered in the tissue engineering (TE) field, expanding from bone to soft TE. The success of BGs in hard and soft TE applications is based on the biochemical reactions occurring at the interface between BGs and the biological environment, involving the release of biologically active ionic dissolution products from the BG matrix [2]. The progress in the development and characterization of TE scaffolds made purely from BGs or by combining BGs and biopolymers, including their application in biofabrication approaches, will be discussed with focus on the effect of different biologically active ions released from BGs on osteogenesis and angiogenesis. Research involves BGs incorporating metallic ions such as B, Sr, Cu, Nb, Co, Li, Mn among other active ions. The variation of ion concentration in the medium as function of time and the time dependent effects on stem cells will be discussed, which is required for the comprehensive assessment of the long-term biological performance of BGs with implication for clinical applications. Moreover in-vivo investigations to determine the vascularisation potential of new bioactive glass scaffolds will be discussed in relation to the current main challenge of TE, namely that the biomaterial construct supports vascularisation. The key characteristics of BGs in terms of inorganic bioactivity (ability to bond to biologcal tissues via specific surface reactivity) and their angiogenic potential coupled with antibacterial and hemostatic properties, are the key elements enabling such applications in contact with soft tissues [3]. In the emerging field of bioactive glasses for soft tissue engineering, an overview of such applications will be presented with focus on our current work on dressings for wound healing based on combinations of BGs and phytotherapeutic agents [4] and on hydrogel-bioactive glass composites for biofabrication of cell laden scaffolds.
References:
[1] L.L. Hench, et al., Bonding mechanisms at the interface of ceramic prosthetic materials, J. Biomed. Mater. Res. 5 (1971) 117–141. [2] A. Hoppe, et al., A review of the biological response to ionic dissolution products from bioactive glasses and glass-ceramics, Biomaterials 32 (2011) 2757-2774. [3] V. Miguez-Pacheco, et al., Bioactive glasses beyond bone and teeth: emerging applications in contact with soft tissues, Acta Biomaterialia 13 (2015) 1-15. [4] K. Schuhladen, et al., Production of a novel poly (ɛ‐caprolactone)‐methylcellulose electrospun wound dressing by incorporating bioactive glass and Manuka honey, J. Biomed. Mater. Res. Part B (2020) in press.