Primena biomimičnih bioreaktora u dizajniranju i karakterizaciji novih biomaterijala za inženjerstvo tkiva

Abstract

Cilj istraživanja u ovoj doktorskoj disertaciji je bila primena biomimičnih bioreaktora za sveobuhvatnu i fiziološki relevantnu karakterizaciju novih bioaktivnih biomaterijala za potencijalnu primenu u inženjerstvu tkiva, a time i razvoj novih metodologija za pouzdanu evaluaciju biomaterijala. Ispitani su nanokompozitni hidrogelovi alginata sa nanočesticama srebra za inženjerstvo tkiva artikularne hrskavice i hidrogelovi gelanske gume sa nanočesticama bioaktivnog stakla za inženjerstvo tkiva kosti i osteohondralnog tkiva primenom dva biomimična bioreaktora: protočnog i bioreaktora sa dinamičkom kompresijom. Poseban cilj ove disertacije je bio i razvoj novog bioreaktora za inženjerstvo tkiva intervertebralnog diska. Ispitivanja nanokompozitnih Ag/alginatih hidrogelova baziranih na dve vrste alginata pokazala su da polazni sastav alginata utiče na veličinu i kinetiku otpuštanja nanočestica srebra i mehaničke karakteristike hidrogelova u fiziološki relevantnim bioreaktorskim uslovima, na osnovu kojih je određena njihova potencijalna primena. Kinetika otpuštanja srebra je uspešno modelovana prenosom mase difuzijom i konvekcijom. Makroporozni hidrogelovi na bazi gelanske gume i bioaktivnog stakla sa otvorenim porama su dobijeni unapređenom procedurom, a u fiziološki relevantnim uslovima u protočnom bioreaktoru došlo je do značajnog formiranja kalcijum fosfata i poboljšanja mehaničkih karakteristika. Razvijena je i jednostavna metoda za dobijanje dvofaznih osteohondralnih implantata sa dobrom integracijom između slojeva. Rezultati dobijeni u ovoj doktorskoj disertaciji su potvrdili značaj i široki potencijal primene biomimičnih bioreaktora i sprovedene metodologije u više naučnih oblasti, od razvoja novih biomaterijala i inženjerstva tkiva do nanotoksikologije i biologije ćelija.

The aim of this doctoral dissertation was application of biomimetic bioreactors for comprehensive and physiologically relevant characterization of novel, bioactive biomaterials intended for tissue engineering (TE), and, consequently development of new methodologies for reliable biomaterial evaluation, as well. The focus was on nanocomposite alginate hydrogels with silver nanoparticles (AgNPs) for articular cartilage TE and gellan gum hydrogels with bioactive glass nanoparticles (GG-BAG) for bone and osteochondral TE, while two biomimetic bioreactors were applied: perfusion and a bioreactor with dynamic compression. The specific goal of this dissertation was also development of a novel bioreactor for intervertebral disc TE. Investigation of nanocomposite Ag/alginate hydrogels based on two alginate types has shown that the initial alginate composition affects the size and release kinetics of AgNPs, as well as hydrogel mechanical properties under physiologically relevant bioreactor conditions, which indicated the potential use for each alginate hydrogel type. The silver release kinetics was successfully modeled by mass transfer by diffusion and advection-diffusion. Macroporous GG-BAG hydrogels with open pores were obtained by a novel procedure. Physiologically relevant conditions in perfusion bioreactors enhanced calcium phosphate formation and improved hydrogel mechanical properties. Also, a simple method was developed for obtaining biphasic osteochondral implants with good integration between layers. The obtained results indicate the significance and vast potentials of biomimetic bioreactors and methodologies developed in this doctoral dissertation for applications in different scientific fields from biomaterials science and TE to nanotoxicology and cell biology.