Electrospun Poly(butylene-adipate-co-terephthalate)/Nano-hyDroxyapatite/Graphene Nanoribbon Scaffolds Improved the In Vivo Osteogenesis of the Neoformed Bone

Abstract

Electrospun ultrathin fibrous scaffold filed with synthetic nanohydroxyapatite (nHAp) and graphene nanoribbons (GNR) has bioactive and osteoconductive properties and is a plausible strategy to improve bone regeneration. Poly(butylene-adipate-co-terephthalate) (PBAT) has been studied as fibrous scaffolds due to its low crystallinity, faster biodegradability, and good mechanical properties; however, its potential for in vivo applications remains underexplored. We proposed the application of electrospun PBAT with high contents of incorporated nHAp and nHAp/GNR nanoparticles as bone grafts. Ultrathin PBAT, PBAT/nHAp, and PBAT/nHAp/GNR fibers were produced using an electrospinning apparatus. The produced fibers were characterized morphologically and structurally using scanning electron (SEM) and high-resolution transmission electron (TEM) microscopies, respectively. Mechanical properties were analyzed using a texturometer. All scaffolds were implanted into critical tibia defects in rats and analyzed after two weeks using radiography, microcomputed tomography, histological, histomorphometric, and biomechanical analyses. The results showed through SEM and high-resolution TEM characterized the average diameters of the fibers (ranged from 0.208 µm ± 0.035 to 0.388 µm ± 0.087) and nHAp (crystallite around 0.28, 0.34, and 0.69 nm) and nHAp/GNR (200–300 nm) nanoparticles distribution into PBAT matrices. Ultrathin fibers were obtained, and the incorporated nHAp and nHAp/GNR nanoparticles were well distributed into PBAT matrices. The addition of nHAp and nHAp/GNR nanoparticles improved the elastic modulus of the ultrathin fibers compared to neat PBAT. High loads of nHAp/GNR (PBATnH5G group) improved the in vivo lamellar bone formation promoting greater radiographic density, trabecular number and stiffness in the defect area 2 weeks after implantation than control and PBAT groups.

Collagen-chitosan-hydroxyapatite composite scaffolds for bone repair in ovariectomized rats

“…There is still a preference for the use of autologous grafts for bone grafting; however, due to the need for two surgical beds (donor and recipient area), morbidity and limited availability, advantages arise in the use of synthetic biomaterials for bone tissue regeneration 47 . Three-dimensional scaffolds are particularly interesting in tissue engineering since they can act as structures to accommodate cells and support tissue growth, providing support for cell adhesion, proliferation, and migration 48 . The creation of a bone defect triggers a sequence of events in the local microenvironment, including the migration of inflammatory and proliferative cells of bone tissue, compatible with the remodeling process.…”

A scoping review of graphene-based biomaterials for in vivo bone tissue engineering

“…109,110 All animal models successfully compared osteogenesis capability, but the size of the defect was not adequately described to make a pattern for later comparison. However, the sites of the defect could be listed as a cranial defect in 49 experiments, 31,35,39–44,47–50,52,54–56,59–63,65,67,69,71–75,77–81,83,84,86–91,93,94,96,98,100,109,110 limb defect in 25 experiments, 36–38,45,46,51,53,58,64,66,68,70,76,82,85,92,95,97,99,101–103,105–107 or jaw defect in four experiments. 39,57,104,108 These findings may reflect the exposition to functional charges or not during bone repair.…”

“…77 experiments were assessed in the manuscripts reviewed. Calcium was associated with graphene in 30 experiments, 37,38,40,41,46,47,[58][59][60][61][62][63]66,77,78,[81][82][83]85,88,89,[94][95][96][97][98]102,106,107,110 with 35 experiments presenting the association of graphene with Natural Polymers, 35,39,[42][43][44][45]47,[50][51][52]56,58,59,[62][63][64][66][67][68][69][70]…”

The Local Release of Teriparatide Incorporated in 45S5 Bioglass Promotes a Beneficial Effect on Osteogenic Cells and Bone Repair in Calvarial Defects in Ovariectomized Rats

“…Currently, autogenous bone is considered the gold standard in the replacement of bone defects [ 8 ], but the disadvantages associated with autogenous bone, such as the need for more than one surgical site, limited availability, and the possibility of the post-complications [ 9 , 10 , 11 ], have motivated the development of new biomaterials used in bone repair [ 12 , 13 ], particularly bioglass, which has excellent physical–chemical properties and a long history of applications as biomedical fillers, which has stimulated several researchers to test the use of these materials in tissue engineering and regeneration strategies [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. Furthermore, the discovery of bioglass as the first artificial material with a clear ability to form an integrated bond with bones has stimulated the interest of scientists and clinicians for a long time [ 22 ].…”