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Abstract: Nanotechnology has enabled the engineering of nanostructured materials to meet current challenges in bone replacement therapies. Biocomposite nanofibrous scaffolds of poly(l-lactic acid)-co-poly(ɛ-caprolactone), gelatin and hydroxyapatite (HA) were fabricated by combining the electrospinning and electrospraying techniques in order to create a better osteophilic environment for the growth and mineralization of osteoblasts. Electrospraying of HA nanoparticles on electrospun nanofibers helped to attain rough surface morphology ideal for cell attachment and proliferation and also achieve improved mechanical properties than HA blended nanofibers. Nanofibrous scaffolds showed high pore size and porosity up to 90% with fiber diameter in the range of 200–700nm. Nanofibrous scaffolds were characterized for their functional groups and chemical structure by FTIR and XRD analysis. Studies on cell–scaffold interaction were carried out by culturing human fetal osteoblast cells (hFOB) on both HA blended and sprayed PLACL/Gel scaffolds and assessing their growth, proliferation, mineralization and enzyme activity. The results of MTS, ALP, SEM and ARS studies confirmed, not only did HA sprayed biocomposite scaffolds showed better cell proliferation but also enhanced mineralization and alkaline phosphatase activity (ALP) proving that electrospraying in combination with electrospinning produced superior and more suitable biocomposite nanofibrous scaffolds for bone tissue regeneration. [Copyright &y& Elsevier]

Different biomaterials have been used as scaffolds for bone tissue engineering. Here we characterize a biomaterial composed of sintered (1100°C) and powdered hydroxyapatite (HA) and type I collagen (Coll), both of bovine origin, designed for osteoconductive and osteoinductive scaffolds. Coll/HA proportions were 1/2.6 and 1/1 (wet weight), and particles sizes varied from 200 to 400 μm. Vv (volume density) and Sv (surface to volume density) for the HA particles in the composite ranged from 0.48±0.06 to 0.55±0.02 and 5.090±0.545 to 6.366±0.289 μm−1, respectively. Due to the relatively small changes in Vv and Sv, a macroporosity could be characterized for the biocomposite. X-ray diffraction and infrared spectroscopy showed that the sintered bone was composed essentially of HA with minimum additional groups such as surface calcium hydroxide, surface and crystal water, free carbon dioxide and possibly brushite. Mass spectrometry detected carbonates at A and B sites of HA, and weakly bound to the structure. Human osteoblasts adhered and spread on both the HA particle surface and the collagen fibers, which seemed to guide cells between adjacent particles. The biocomposite studied has several characteristics considered as ideal for its use as a scaffold for osteoconduction and osteoinduction. [Copyright &y& Elsevier]

• Functionalized nHAp was obtained using arginine or polyethylenimine. • Resulted nanoparticles were comparatively characterized relative to used modifiers. • Linear polyethylenimine coated hydroxyapatite had the best DNA binding ability. • Use of LPEI functionalized nHAp in biocomposites recipe had a strengthening effect. • The 3D constructs demonstrated rapid self–recovery and fatigue resistant behavior. Functionalized nano-hydroxyapatite (nHAp) was obtained by wet chemical technique, using arginine (Arg) or polyethylenimine (branched-bPEI, or linear-LPEI) as cationic modifiers and dispersing agents. TEM, FT-IR, SEM, DLS and WAXD characterization results showed that the prepared nanoparticles possessed needle- or plate-like morphologies and Arg and PEI were successfully grafted onto nHAp. LPEI functionalized nHAp exhibited a good similitude with biological apatite and the best DNA binding ability. In addition, the incorporation of nHAp/LPEI nanoparticles within collagen/dimethylsilanediol hyaluronate-based porous matrices pointed out a significant improvement of the compressive modulus of biocomposites: up to a six-fold increase, compared with the polymer matrix without fillers. Moreover, the composite sponges revealed high toughness during five consecutive compression tests without any permanent deformation and cracks. Therefore, nHAp/LPEI nanoparticles could be considered promising materials for biomedical applications, like gene carrier or reinforcement filler with strong interfacial adhesion in biocomposites for bone engineering. [ABSTRACT FROM AUTHOR]