MPS-HEMA Ormosils

Although the biocompatibility and biodegradability of these materials were rapidly determined, the bioactivity of Si02-PCL hybrid materials was not studied until recently [99]. In order to provide bioactivity to Si02-PCL hybrid materials, Rhee prepared triethoxysilane end-capped poly(s-caprolactone) which was then cocondensed with tetraethyl orthosilicate and calcium nitrate via the sol-gel method. The Ca-containing PCL/silica hybrid so obtained showed in vitro bioactivity and biodegradability. The hybridization procedure between the a,co-hydroxyl PCL and silica phases was proposed to be as follows  

End-capping of both ends of a,co-hydroxyl PCL with 3-isocyanatopropyl triethoxysilane (IPTS). 

Two hydroxyl groups in the PCL structure react with the isocyanate group in the IPTS and form a urethane linkage. 

Regardless of the composition, the synthesis conditions also play an important role in the bioactivity and mechanical properties [ 101 ]. When PCL/silica hybrid materials 

Bioactive glasses are currently used as granulate for bone and dental grafting in small defects, or as powder incorporated into toothpaste. Although silica-based bioactive glasses meant an extraordinary advance in the field of bone tissue regeneration, their application as pieces for medium and large defects is not possible due to their very poor mechanical properties. 

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