enzymatically active silicatein that had been encapsulated in poly(D,L-lactide)/
polyvinyl pyrrolidone-based microspheres (Wiens et al. 2010a). Application of
this material to treat artificial defects in rabbit femurs resulted in a complete
restoration of HA and bone regeneration. Therefore, it has been concluded that
biosilica might be useful for healing of bone fractures/defects also in vivo (Wiens
et al. 2010b). Moreover, the presented results show that biosilica is a selective
inducer of OPG expression but not of RANKL expression (Wiens et al. 2010c). As a
consequence, increased amounts of the cytokine OPG are released by the
osteoblasts. In the extracellular space, OPG binds to and hence sequesters
RANKL which becomes incapable of binding to its receptor RANK. The abolishment of the function of RANKL is expected to result in an inhibition of osteoclast
differentiation and of bone resorption. Hence, biosilica has been proposed to
possess a considerable potential for treatment and prophylaxis of osteoporosis
(Wiens et al. 2010c). Studies are going on to examine the promising biological
effects of biosilica in vivo, in animal experiments. In addition, a combined application of polymeric silica with other inorganic polymers, in particular inorganic
polyphosphates (Leyhausen et al. 1998; Schr€ oder et al. 2000b; Lorenz and Schr€ oder
2001), will be considered as well.
Acknowledgments This work was supported by grants from the Bundesministerium f€ ur Bildung
und Forschung (project “Center of Excellence BIOTECmarin”), the Deutsche Forschungsgemeinschaft (Schr 277/10-1), the European Commission (no PITN-GA-2008-215507 –
BIOMINTEC), the BiomaTiCS consortium of the Mainz University Medical Center, the Johannes
Gutenberg University Research Center for Complex Matter (COMATT), and the International S &
T Cooperation Program of China (Grant No. 2008DFA00980). W.E.G.M. is a holder of an ERC
Advanced Grant (no 268476 BIOSILICA).
References
Adachi JD (1997) Corticosteroid-induced osteoporosis. Am J Med Sci 313:41–49
Adler AJ, Berlyne GM (1986) Silicon metabolism II. Renal handling chronic renal failure patients.
Nephron 44:36–39
Adler AJ, Etzion Z, Berlyne GM (1986) Uptake, distribution, and excretion of 31silicon in normal
rats. Am J Physiol 251:E670–E673
Adkisson HD, Strauss-Schoenberger J, Gillis M, Wilkins R, Jackson M, Hruska KA (2000) Rapid
quantitative bioassay of osteoinduction. J Orthop Res 18:503–511
Albrektsson T, Johansson C (2001) Osteoinduction, osteoconduction and osseointegration. Eur
Spine J 10:S96–S101
Ammann P, Shen V, Robin B, Mauras Y, Bonjour JP, Rizzoli R (2004) Strontium ranelate
improves bone resistance by increasing bone mass and improving architecture in intact female
rats. J Bone Miner Res 19:2012–2020
Arumugam MQ, Ireland DC, Brooks RA, Rushton N, Bonfield W (2006) The effect of orthosilicic
acid on collagen type I, alkaline phosphatase and osteocalcin mRNA expression in human
bone-derived osteoblasts in vitro. Key Eng Mater 32:309–311
Berlyne GM, Adler AJ, Ferran N, Bennett S, Holt J (1986) Silicon metabolism I: some aspects of
renal silicon handling in normal man. Nephron 43:5–9
304
H.C. Schr€ oder et al.
polyvinyl pyrrolidone-based microspheres (Wiens et al. 2010a). Application of
this material to treat artificial defects in rabbit femurs resulted in a complete
restoration of HA and bone regeneration. Therefore, it has been concluded that
biosilica might be useful for healing of bone fractures/defects also in vivo (Wiens
et al. 2010b). Moreover, the presented results show that biosilica is a selective
inducer of OPG expression but not of RANKL expression (Wiens et al. 2010c). As a
consequence, increased amounts of the cytokine OPG are released by the
osteoblasts. In the extracellular space, OPG binds to and hence sequesters
RANKL which becomes incapable of binding to its receptor RANK. The abolishment of the function of RANKL is expected to result in an inhibition of osteoclast
differentiation and of bone resorption. Hence, biosilica has been proposed to
possess a considerable potential for treatment and prophylaxis of osteoporosis
(Wiens et al. 2010c). Studies are going on to examine the promising biological
effects of biosilica in vivo, in animal experiments. In addition, a combined application of polymeric silica with other inorganic polymers, in particular inorganic
polyphosphates (Leyhausen et al. 1998; Schr€ oder et al. 2000b; Lorenz and Schr€ oder
2001), will be considered as well.
Acknowledgments This work was supported by grants from the Bundesministerium f€ ur Bildung
und Forschung (project “Center of Excellence BIOTECmarin”), the Deutsche Forschungsgemeinschaft (Schr 277/10-1), the European Commission (no PITN-GA-2008-215507 –
BIOMINTEC), the BiomaTiCS consortium of the Mainz University Medical Center, the Johannes
Gutenberg University Research Center for Complex Matter (COMATT), and the International S &
T Cooperation Program of China (Grant No. 2008DFA00980). W.E.G.M. is a holder of an ERC
Advanced Grant (no 268476 BIOSILICA).
References
Adachi JD (1997) Corticosteroid-induced osteoporosis. Am J Med Sci 313:41–49
Adler AJ, Berlyne GM (1986) Silicon metabolism II. Renal handling chronic renal failure patients.
Nephron 44:36–39
Adler AJ, Etzion Z, Berlyne GM (1986) Uptake, distribution, and excretion of 31silicon in normal
rats. Am J Physiol 251:E670–E673
Adkisson HD, Strauss-Schoenberger J, Gillis M, Wilkins R, Jackson M, Hruska KA (2000) Rapid
quantitative bioassay of osteoinduction. J Orthop Res 18:503–511
Albrektsson T, Johansson C (2001) Osteoinduction, osteoconduction and osseointegration. Eur
Spine J 10:S96–S101
Ammann P, Shen V, Robin B, Mauras Y, Bonjour JP, Rizzoli R (2004) Strontium ranelate
improves bone resistance by increasing bone mass and improving architecture in intact female
rats. J Bone Miner Res 19:2012–2020
Arumugam MQ, Ireland DC, Brooks RA, Rushton N, Bonfield W (2006) The effect of orthosilicic
acid on collagen type I, alkaline phosphatase and osteocalcin mRNA expression in human
bone-derived osteoblasts in vitro. Key Eng Mater 32:309–311
Berlyne GM, Adler AJ, Ferran N, Bennett S, Holt J (1986) Silicon metabolism I: some aspects of
renal silicon handling in normal man. Nephron 43:5–9
304
H.C. Schr€ oder et al.