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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.

Poly (lactic acid) (PLA) has been increasingly used in cutaneous tissue engineering due to its low cost, ease of handling, biodegradability, and biocompatibility, as well as its ability to form composites. However, these polymers possess a structure with nanoporous that mimic the cellular environment. In this study, nanocomposites are prepared using PLA and titanium dioxide (TiO₂) (10 and 35%—w/w) nanoparticles that also function as an active anti-scarring agent. The nanocomposites were prepared using an electrospinning technique. Three different solutions were prepared as follows: PLA, 10% PLA/TiO₂, and 35% PLA/TiO₂ (w/w%). Electrospun PLA and PLA/TiO₂ nanocomposites were characterized morphologically, structurally, and chemically using electron scanning microscopy, transmission electron microscopy, goniometry, and X-ray diffraction. L929 fibroblast cells were used for in vitro tests. The cytotoxic effect was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Versicam (VCAN), biglicam (BIG), interleukin-6 (IL6), interleukin-10 (IL-10), and type-1 collagen (COL1A1) genes were evaluated by RT-qPCR. In vivo tests using Wistar rats were conducted for up to 15 days. Nanofibrous fibers were obtained for all groups that did not contain residual solvents. No cytotoxic effects were observed for up to 168 h. The genes expressed showed the highest values of versican and collagen-1 (p < 0.05) for PLA/TiO₂ nanocomposite scaffolds when compared to the control group (cells). Histological images showed that PLA at 10 and 35% w/w led to a discrete inflammatory infiltration and expression of many newly formed vessels, indicating increased metabolic activity of this tissue. To summarize, this study supported the potential of PLA/TiO₂ nanocomposites ability to reduce cutaneous scarring in scaffolds.