Bioactive materials based on calcium phosphates and mesoporous bioglass ion-doped with magnesium and/or strontium: synthesis, processing, characterization and biomedical application

[T. Matić]

122 str.

Tehnološko inženjerstvo - Inženjerstvo materijala / Technological engineering -Materials Engineering

U okviru ove doktorske disertacije sintetisani su i ispitani prahovi na bazi kalcijum-fosfata (CaP) i mezoporoznog bioaktivnog stakla (MBAG) dopirani jonima magnezijuma (Mg2+) i/ili stroncijuma (Sr2+). Različitim metodama procesiranja, a polazeći od sintetisanih prahova, dobijeni su kontrolisano porozni kompakti i makroporozni nosači ćelija, a u nastavku je ispitan njihov potencijal za primenu u stomatologiji i biomedicini. Pokazano je da istovremeno prisustvo jona Sr2+ i Mg2+ u strukturi hidroksiapatita (HAP) destabiliše HAP rešetku, rezultujući bifaznim CaP sastavom, dok prilikom sinterovanja stabiliše b- TCP fazu odlaganjem transformacije u a-TCP. Najbolja mehanička svojstva su potvrđena kod SrMgHAP uzorka dopiranog sa po 3 mol.% Sr2+ i Mg2+ (5,02 GPa i 1,12 MPa‧m1/2). Sferne nanočestice SrMgMBAG su uspešno sintetisane mikroemulzionom tehnikom. Binarno dopiranje je uticalo na stvaranje radijalne dendritske mezoporozne strukture, što je ubrzalo otpuštanje leka ibuprofena u poređenju sa nedopiranim česticama. Procesirani kompakti kotrolisane poroznosti na bazi dopiranih HAP su ispitani za primenu u stomatologiji u vidu dentalnih inserata. Predložen je novi protokol za restauraciju velikih kaviteta zuba korišćenjem dentalnih inserata na bazi HAP. Ekstrahovani ljudski molari restaurirani korišćenjem konvencionalnog postupka i primenom novopredloženog protokola su imali sličnu otpornost na lom. Dobijeni makroporozni nosači ćelija na bazi SrMgCaP i njihovi kompoziti sa MBAG predstavljaju adekvatne nosače ćelija za primenu u inženjerstvu koštanog tkiva, omogućuju dobru adheziju i proliferaciju BM-MSC i EA.hy926 ćelija, ali i pokazuju pro-osteogena i pro-angiogena svojstva. Nanošenje biorazgradive biokompozitne prevlake na bazi želatina i čestica Sr,MgMBAG je značajno poboljšalo pritisnu čvrstoću makroporoznih nosača.

Within this doctoral dissertation powders based on calcium phosphates (CaP) and mesoporous bioactive glass (MBAG) doped with magnesium (Mg2+) and/or strontium (Sr2+) ions were synthesized. Using various techniques the obtained powders were processed in the form of compacts with controlled porosity, or scaffolds, and their possible biomedical or dental application was evaluated. It was shown that simultaneous presence of Sr2+ and Mg2+ in the hydroxyapatite (HAP) structure destabilizes the HAP lattice resulting in the biphasic CaP composition, while also stabilizing the b-TCP phase during sintering by postponing its transformation into a-TCP. The best mechanical properties were obtained in the case of SrMgHAP doped with 3 mol.% of Sr2+ and Mg2+ (5,02 GPa i 1,12 MPa‧m1/2). Spherical SrMgMBAG nanoparticles were successfully synthesized using microemulsion sol- gel technique. The binary doping influenced formation of radial dendritic mesoporous structure, which increased the rate of ibuprofen drug release, compared to pristine particles. Obtained compacts with controlled porosity based on doped HAP were analyzed for application in dentistry as dental inserts. A novel protocol for restoration of large tooth cavities using dental inserts based on HAP was proposed. Extracted human molars were restored using convectional and novel protocols, and their fracture resistance was shown to be similar. Fabricated scaffolds based on SrMgCaP and their composites with MBAG were shown to be adequate cell carriers for application in bone tissue engineering, by showing good cells adhesion and proliferation of BM-MSC and EA.hy926 cells, as well as pro-osteogenic and pro-angiogenic properties. Coating the scaffolds with biodegradable biocomposites based on gelatine and SrMgMBAG particles showed significantly improved compressive strength of the scaffolds

kalcijum-fosfati; mezoporozno bioaktivno staklo; dentalni insert; skafoldi

calcium phosphates; mesoporous bioactive glass; dental insert; scaffold

666.1.017:616.314-74(043.3)

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