New Approach to Bone Tissue Engineering: Simultaneous Application of Hydroxyapatite and Bioactive Glass Coated on a Poly(l-lactic acid) Scaffold

Abstract

A combination of bioceramics and polymeric nanofibers holds promising potential for bone tissue engineering applications. In the present study, hydroxyapatite (HA), bioactive glass (BG), and tricalcium phosphate (TCP) particles were coated on the surface of electrospun poly(L-lactic acid) (PLLA) nanofibers, and the capacity of the PLLA, BG-PLLA, HA-PLLA, HA-BG-PLLA, and TCP-PLLA scaffolds for bone regeneration was investigated in rat critical-size defects using digital mammography, multislice spiral-computed tomography (MSCT) imaging, and histological analysis. Electrospun scaffolds exhibited a nanofibrous structure with a homogeneous distribution of bioceramics along the surface of PLLA nanofibers. A total of 8 weeks after implantation, no sign of complication or inflammation was observed at the site of the calvarial bone defect. On the basis of imaging analysis, a higher level of bone reconstruction was observed in the animals receiving HA-, BG-, and TCP-coated scaffolds compared to an untreated control group. In addition, simultaneous coating of HA and BG induced the highest regeneration among all groups. Histological staining confirmed these findings and also showed an efficient osseointegration in HA-BG-coated nanofibers. On the whole, it was demonstrated that nanofibrous structures could serve as an appropriate support to guide the healing process, and coating their surface with bioceramics enhanced bone reconstruction. These bioceramic-coated scaffolds can be used as new bone-graft substitutes capable of efficiently inducing osteoconduction and osseointegration in orthopedic fractures and defects.

pH-dependent antibacterial effects on oral microorganisms through pure PLGA implants and composites with nanosized bioactive glass

“…To our best knowledge, among the different techniques used to produce BG-polymer composites [1,11,13], up to now, electrospinning has only been applied with sodium-free bioactive glass [27][28][29][30][31][32][33][34]. Usually, the electrospinning solution was obtained by mixing a solgel precursor of BG with a polymer solution.…”

Interação biológica de membranas poliméricas bioativas em falhas ósseas induzidas em tíbias de coelhos

“…Aos sete e 14 dias, no grupo controle, verificou-se áreas focais de matriz óssea e cartilaginosa com osteoclastos na região de matriz osteoide, indicando que o processo de reparo estava ocorrendo conforme o esperado em situações sem tratamento (RUMI et al, 2005;ROZEN et al, 2007;SCHINDELER et al, 2008;RAGGATT, 2010;ROSENBERG, 2010 (CALLAN, 1993;SZABO et al, 2005;FARDIN et al, 2010;DINARVAND et al, 2011;RAGETLY;GRIFFON, 2011). , 2007).…”

“…Não foi objetivo do trabalho elucidar os mecanismos osteoindutores dos polímeros usados, mas, com base na literatura consultada, é pertinente supor que a osteoindução está relacionada aos eventos supracitados. ZHANG et al, 2004;ROSANNA;VITTORIO;SANTI, 2004;SANG-HOON, 2004;DECLERCQ et al, 2005;DINARVAND et al, 2011), sendo a formação óssea, mediante osteoindução e osteocondução, dependente do recrutamento de precursores mesenquimais que sofrem diversas fases proliferativas antes da diferenciação em um fenótipo que suporta a deposição de matriz e sua mineralização (DINARVAND et al, 2011;RAGETLY;GRIFFON, 2011).…”

“…Os biomateriais poliméricos usados no experimento, por possuírem propriedades bioativas incluindo osteoindução, osteocondução e sinalização celular (MENEZES;FREITAS;GONÇALVES, 2009;OLIVEIRA, 2010;ROCHA, 2010;DINARVAND et al, 2011) ZHANG et al, 2004;ROSANNA;VITTORIO;SANTI, 2004;SANG-HOON, 2004;DECLERCQ et al, 2005;DEBUSSCHER et al, 2009).…”

“…A aceleração da formação óssea é requerida em diversas situações onde o reparo ósseo está prejudicado, incluindo não uniões, artrodeses ou fusão espinhal e em preenchimento de defeitos após fratura, osteotomia, ostectomia ou ressecção tumoral (WARRER et al, 1991;EL-WARRAK et al, 2004;JUNG et al, 2005;RAGETLY;GRIFFON, 2011 ZHANG, 2004;ROSANNA;VITTORIO;SANTI, 2004;SANG-HOON, 2004;DECLERCQ et al, 2005;SHIRANE et al, 2010;DINARVAND et al, 2011 (ROZEN et al, 2007;SCHINDELER et al, 2008). …”