Gelatin/nanoceria nanocomposite fibers as antioxidant scaffolds for neuronal regeneration.

BACKGROUND: The design of efficient nerve conduits able to sustain the axonal outgrowth and its guidance towards appropriate targets is of paramount importance in nerve tissue engineering. METHODS: In this work, we propose the preparation of highly aligned nanocomposite fibers of gelatin/cerium oxide nanoparticles (nanoceria), prepared by electrospinning. Nanoceria are powerful self-regenerative antioxidant nanomaterials, that behave as strong reactive oxygen species scavengers, and among various beneficial effects, they have been proven to inhibit the cell senescence and to promote the neurite sprouting. RESULTS: After a detailed characterization of the developed substrates, they have been tested on neuron-like SH-SY5Y cells, demonstrating strong antioxidant properties and beneficial multi-cue effects in terms of neurite development and alignment. CONCLUSIONS: Obtained findings suggest efficiency of the proposed substrates in providing combined topographical stimuli and antioxidant effects to cultured cells. GENERAL SIGNIFICANCE: Proposed nanocomposite scaffolds represent a promising approach for nerve tissue engineering and regenerative medicine.

Nanostructured scaffold with biomimetic and antibacterial properties for wound healing produced by 'green electrospinning'.

HYPOTHESIS: Wound healing is a complex process that often requires treatment with antibacterial agents to avoid infection, which affects the optimal tissue regeneration process. Ideal scaffolds for wound healing treatment should combine biomimetic features to ensure the tissue growth on properly designed extracellular matrix (ECM)-like scaffolds and antibacterial properties in order to avoid bacterial colonization. EXPERIMENTS: In this work, gelatin cross-linked nanofibers (GL-nanofibres), with diameters ranging from 200 to 300 nm, were prepared via a "green electrospinning technique" to mimic the structure and composition of the extracellular matrix (ECM), and promote the normal skin wound healing process. Nanofibres were doped with two antibacterial agents (gentamicin sulphate or silver nanoparticles) to achieve an antibacterial effect against Gram + and Gram- bacteria. FINDINGS: The ECM-mimicking structure of GL-nanofibres was not affected by the presence of the antibacterial agents, which were homogeneously distributed within the mats as shown by SEM and EDS. The antibacterial properties of the developed matrices were confirmed using 4 strains (S. aureus, S. epidermidis, P. aeruginosa and E. coli) while the biocompatibility of the developed substrates and their ability to induce cell growth was assessed using Neonatal Normal Human Dermal Fibroblasts (NHDF-Neo).

Non-covalently crosslinked chitosan nanofibrous mats prepared by electrospinning as substrates for soft tissue regeneration.

Chitosan (CS) membranes obtained by electrospinning are potentially ideal substrates for soft tissue engineering as they combine the excellent biological properties of CS with the extracellular matrix (ECM)-like structure of nanofibrous mats. However, the high amount of acid solvents required to spun CS solutions interferes with the biocompatibility of CS fibres. To overcome this limitation, novel CS based solutions were investigated in this work. Low amount of acidic acid (0.5M) was used and dibasic sodium phosphate (DSP) was introduced as ionic crosslinker to improve nanofibres water stability and to neutralize the acidic pH of electrospun membranes after fibres soaking in biological fluids. Randomly oriented and aligned nanofibres (128±19nm and 140±41nm, respectively) were obtained through electrospinning process (voltage of 30kV, 30µL/min flow rate and temperature of 39°C) showing mechanical properties similar to those of soft tissues (Young Modulus lower than 40MPa in dry condition) and water stability until 7 days. C2C12 myoblast cell line was cultured on CS fibres showing that the aligned architecture of substrate induces cell orientation that can enhance skeletal muscle regeneration.