Surface functionalisation of sol-gel-based bioactive glass scaffolds for drug delivery

37-4 26 h Eu opean Con e ence on Bioma e ials, Li e pool, 31s Augus – 3 d Sep embe 2014 Su ace unc ionalisa ion o sol-gel-based bioac i e glass sca olds o d ug deli e y A. Philippa 1*, A. M. Bel án2, L. Pon i oli3, C.Vi ale-B o a one3, E. Spiecke 2 and A. R. Boccaccini1 1Ins i u e o Bioma e ials, Uni e si y E langen-Nü nbe g, Ge many, anahi.philippa [email p o ec ed]e 2Cen e o Nanoanalysis and Elec on Mic oscopy (CENEM), Uni e si y E langen-Nü nbe g, Ge many 3Ins i u e o Ma e ials Physics and Enginee ing, Applied Science and Technology Dep ., Poli ecnico di To ino, I aly INTRODUCTION Bioac i e glasses a e widely used in bone issue enginee ing (BTE) since hey can de elop s ong bonds wi h bone h ough he o ma ion o a hyd oxyapa i e (HA) laye 1. Wi hin hese ma e ials, sol-gel-based bioac i e glasses (SGBGs) a e a ac i e due o hei enhanced bioac i i y and eso babili y and hei capaci y o being unc ionalised wi h a la ge a ie y o moie ies2-3. Su ace unc ionalisa ion is an in e es ing app oach o load d ugs in o he ma e ial and allow hei elease in a con olled manne 3. The aim o his s udy is he de elopmen o new SGBGs o 3D po ous sca olds and unc ionalisa ion o hei su ace by wo di e en me hods4-5 in o de o enhance he d ug deli e y capabili y. EXPERIMENTAL METHODS Bioac i e glass sca olds wi h composi ion (in mol%) 60SiO2 30CaO 5Na2O 5P2O5 we e p epa ed by he sol gel me hod and he oam eplica echnique. Sca olds we e cha ac e ised by scanning elec on mic oscopy (SEM) and µ-CT, in o de o e alua e he mac os uc u e and po osi y and by ansmission elec on mic oscopy (TEM) and N2 adso p ion po osime y using he B unaue -Emme -Telle (BET) app oach o mesopo osi y cha ac e isa ion. Bioac i i y was e ealed by Fou ie ans o m in a ed spec oscopy (FTIR) cha ac e isa ion o he sca olds a e SFB imme sion. A e hea ea men a 700°C, he sca olds su ace was unc ionalised by pos -condensa ion o aminosilane, ollowing he eac ion shown below: A second s ep was conside ed o a oid s e ic in e e ence by adding a space and allowing an op imal loading o he model d ug. Bo h sys ems we e loaded wi h a model d ug, and he d ug elease capabili ies we e s udied in wo di e en media by UV-Vis spec oscopy. RESULTS AND DISCUSSION Sca olds exhibi ed he equi ed mac opo e size (~500μm) as well as high and in e connec ed po osi y, o up o 90% as shown in Fig.1 (a-c). TEM (Fig.1 d) e ealed he mesopo osi y, con i med by BET analysis (po e size: ~4nm; SBET=150m2/g). Bo h po osi ies a e ea u es equi ed by sca olds o BTE and d ug deli e y applica ions1-2. Figu e 1. Images o sca old a,b)SEM mic og aphs, c) µ-CT econs uc ion, d)TEM mic og aph Amino- unc ionalisa ion o he su ace was con i med by ze a po en ial measu emen s, ninhyd ine es as well as by elemen mapping in SEM. The di e en d ug elease p o iles showed ha by su ace unc ionalisa ion i was possible o achie e a educed ini ial bu s elease o he d ug in he es ed media and a long- e m sus ained elease. CONCLUSION Acco ding o SEM and µ-CT econs uc ions, 3D po ous sca olds we e success ully p epa ed, exhibi ing mac o- and mesopo osi y. Fu he mo e, amino- unc ionalised su ace allowed he sys em o exhibi a sus ain elease o he model d ug compa ed o non- unc ionalised sca olds. REFERENCES 1. Ge ha d L.C. e al.,Ma e ials 3:3867-3910, 2010 2. Jones J. R. e al., Bioma e ials 27:964-973, 2006 3. Valle Regi M.e al., Phil. T ans. R. Soc. A 370:1400-1421, 2012 4. Balas F. e al., J. Am. Chem. Soc. 128:8116-8117, 2006 5. Schneide M. e al., Langmui 29:6983-88, 2013 ACKNOWLEDGMENTS The au ho s would like o hank ITN FP-7 p ojec “GlaCERCo” o p o iding inancial suppo ; P. Rosne o he help p o ided in TEM; P o . E. Ve né and D . Sonia Fio illi o he assis ance in he ma e ial cha ac e isa ion; D . A. Inaya o BET analysis.