Herein, we developed honeycomb-like scaffolds by combining poly (d, l-lactic acid) (PDLLA) with a high amount of graphene/multi-walled carbon nanotube oxides (MWCNTO-GO, 50% w/w). From pristine multi-walled carbon nanotubes (MWCNT) powders, we produced MWCNTO-GO via oxygen plasma etching (OPE), which promoted their exfoliation and oxidation. Initially, we evaluated PDLLA and PDLLA/MWCNTO-GO scaffolds for tensile strength tests, cell adhesion and cell viability (with osteoblast-like MG-63 cells), alkaline phosphatase (ALP, a marker of osteoblast differentiation) activity and mineralized nodule formation. In vivo tests were carried out using PDLLA and PDLLA/MWCNTO-GO scaffolds as fillers for critical defects in the tibia of rats. MWCNTO-GO loading was responsible for decreasing the tensile strength and elongation-at-break of PDLLA scaffolds, although the high mechanical performance observed (~600MPa) assures their application in bone tissue regeneration. In vitro results showed that the scaffolds were not cytotoxic and allowed for osteoblast-like cell interactions and the formation of mineralized matrix nodules. Furthermore, MG-63 cells grown on PDLLA/MWCNTO-GO significantly enhanced osteoblast ALP activity compared to controls (cells alone), while the PDLLA group showed similar ALP activity when compared to controls and PDLLA/MWCNTO-GO. Most impressively, in vivo tests suggested that compared to PDLLA scaffolds, PDLLA/MWCNTO-GO had a superior influence on bone cell activity, promoting greater new bone formation. In summary, the results of this study highlighted that this novel scaffold (MWCNTO-GO, 50% w/w) is a promising alternative for bone tissue regeneration and, thus, should be further studied.
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.
<p><strong>Objective: </strong>National and international data show that in the next years the elder population tends to have an exponential increase becoming to be significantly higher than other ages. Among the frequent diseases in the elderly, osteoporosis is a disease that decreases bone mass and deteriorates bone structure causing fragility and a high risk of fracture. This study aimed to evaluate the effect of phytotherapic and homeopathic <em>Arnica montana</em> on bone repair quality and its possible use in the treatment of bone fracture in patients with osteoporosis. <strong>Material and Methods:</strong> This experimental study was performed in Wistar adult female rats divided in 4 groups according to the following treatments: ovariectomized treated with homeopathic<em> A. montana</em> 6CH (OVZ 6CH); ovariectomized treated with phytotherapic <em>A. montana</em> (OVZ TM); ovariectomized with placebo (OVZ PL) and rats with sham surgery and placebo (Sham PL). In a period of 45 days after ovariectomy or sham surgery, all animals got a monocortical lesion. They were euthanized after 6, 12, 18 and 28 days and had the tibiae removed to evaluate dimensions and bone repair by radiographic density, biomechanical test and scanning electronic microscopy (SEM). Data were analyzed by ANOVA and TUKEY tests (p < 0.05). <strong>Results:</strong> Results showed that treatment with <em>Arnica</em> 6CH was better than <em>Arnica</em> TM considering bone resistance and bone repair quality. <strong>Conclusion: </strong>This study concluded that treatment with homeopathic <em>A. montana</em> was more efficient than with phytotherapic Arnica in bone regeneration in rats with osteoporosis.</p><p><strong>Keywords</strong></p><p><em>Arnica montana</em>; Homeopathy; Osteoporosis; Phytotherapy; Radiographic bone density. </p>
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