Crack-free　organic-inorganic　hybrid　monoliths　with　controlled　biomineralization　activity　and　mechanical　property　have　an　important　role　for　highly　efficient　bone　tissue　regeneration.　Here,　biomimetic　and　crack-free　polydimethylsiloxane　(PDMS)-modified　bioactive　glass　(BG)-poly(ethylene　glycol)　(PEG)　(PDMS-BG-PEG)　hybrids　monoliths　were　prepared　by　a　facile　sol-gel　technique.　Results　indicate　that　under　the　assist　of　co-solvents,　BG　sol　and　PDMS　and　PEG　could　be　hybridized　at　a　molecular　level,　and　effects　of　the　PEG　molecular　weight　on　the　structure,　biomineralization　activity,　and　mechanical　property　of　the　as-prepared　hybrid　monoliths　were　also　investigated　in　detail.　It　is　found　that　an　addition　of　low　molecular　weight　PEG　can　significantly　prevent　the　formation　of　cracks　and　speed　up　the　gelation　of　the　hybrid　monoliths,　and　the　surface　microstructure　of　the　hybrid　monoliths　can　be　changed　from　the　porous　to　the　smooth　as　the　PEG　molecular　weight　increases.　Additionally,　the　hybrid　monoliths　with　low　molecular　weight　PEG　show　the　high　formation　of　the　biological　apatite　layer,　while　the　hybrids　with　high　molecular　weight　PEG　exhibit　negligible　biomineralization　ability　in　simulated　body　fluid　(SBF).　Furthermore,　the　PDMS-BG-PEG　600　hybrid　monolith　has　significantly　high　compressive　strength　(32　+/-　3　MPa)　and　modulus　(153　+/-　11　MPa),　as　well　as　good　cell　biocompatibility　by　supporting　osteoblast　(MC3T3-E1)　attachment　and　proliferation.　These　results　indicate　that　the　as-prepared　PDMS-BG-PEG　hybrid　monoliths　may　have　promising　applications　for　bone　tissue　regeneration.　(C)　2015　Elsevier　B.V.　All　rights　reserved.