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PurposeWe tested the potential of bone morphogenic protein 7 (BMP7) and hepatocyte growth factor (HGF) combination gene therapy to treat preformed corneal fibrosis using established rabbit in vivo and human in vitro models.MethodsEighteen New Zealand White rabbits were used. Corneal fibrosis was produced by alkali injury. Twenty-four hours after scar formation, cornea received topically either balanced salt solution (BSS; n = 6), polyethylenimine-conjugated gold nanoparticle (PEI2-GNP)-naked plasmid (n = 6) or PEI2-GNP plasmids expressing BMP7 and HGF genes (n = 6). Donor human corneas were used to obtain primary human corneal fibroblasts and myofibroblasts for mechanistic studies. Gene therapy effects on corneal fibrosis and ocular safety were evaluated by slit-lamp microscope, stereo microscopes, quantitative real-time PCR, immunofluorescence, TUNEL, modified MacDonald-Shadduck scoring system, and Draize tests.ResultsPEI2-GNP–mediated BMP7+HGF gene therapy significantly decreased corneal fibrosis in live rabbits in vivo (Fantes scale was 0.6 in BMP7+HGF-treated eyes compared to 3.3 in −therapy group; P < 0.001). Corneas that received BMP7+HGF demonstrated significantly reduced mRNA levels of profibrotic genes: α-SMA (3.2-fold; P < 0.01), fibronectin (2.3-fold, P < 0.01), collagen I (2.1-fold, P < 0.01), collagen III (1.6-fold, P < 0.01), and collagen IV (1.9-fold, P < 0.01) compared to the −therapy corneas. Furthermore, BMP7+HGF-treated corneas showed significantly fewer myofibroblasts compared to the −therapy controls (83%; P < 0.001). The PEI2-GNP introduced >104 gene copies per microgram DNA of BMP7 and HGF genes. The recombinant HGF rendered apoptosis in corneal myofibroblasts but not in fibroblasts. Localized topical BMP7+HGF therapy showed no ocular toxicity.ConclusionsLocalized topical BMP7+HGF gene therapy treats corneal fibrosis and restores transparency in vivo mitigating excessive healing and rendering selective apoptosis in myofibroblasts.

Polyurethane (PU) based composites were prepared by solvent casting techniques using different wt. % (0-5 wt. %) of reduced graphene oxide (RGO) as reinforcement. Nanoindentation study has been carried out on these composite sheets in order to investigate its nano-mechanical properties. Incorporation of different wt. % RGO in PU matrix led to significant increase in the hardness and elastic modulus of the composites. The maximum nanoindentation hardness of 140 MPa for 5.0 wt. % RGO loading was observed as compared to 58.5 MPa for pure PU (an overall improvement of 139 %). The nanoindentation elastic modulus for 5.0 wt % RGO loaded sample was 881.7 MPa as compared to 385.7 MPa for pure PU (an overall improvement of 129 %). The enhancement in the nano-mechanical properties was correlated with spectroscopic and microscopic investigations using Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Due to their excellent nano-mechanical properties, these composites find their usefulness in structural applications such as automobile and wind mill blade industries. These composites can also be used in hard and scratch-less coating on automotive vehicles. The experimental results were in good agreement with theoretical Raman studies of the GO, RGO and RGO-PU composite films were carried out using Renishaw inVia Raman spectrometer, UK with an excitation source of 785 nm. The nanoindentation study was carried out using IBIS-Nanoindentation (M/S Fisher-Cripps Laboratories Pvt. Limited, Australia), equipped with Berkovich indenter and the other details are given elsewhere 28 . The analysis of the functional groups attached to the GO and RGO planes were studied by FTIR (NICOLET 5700) techniques.In order to make the samples for TEM studies, films were grinded to make it thin (~200 µm). Circular slice of 2.3 mm is cut using ultrasonic cutter. The slice is polished and dimple grinded to make it electron transparent (~ 50 nm at centre).Scheme 2: Process for the synthesis formation of stretchable and flexible RGO reinforced PU composites film

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The present investigation used Linum usitatissimum L. cv. Padmini (linseed), under field conditions in open-top chambers, to evaluate the interactive effects of supplemental ultraviolet-B (sUV-B; ambient +7.2 kJ · m(-2) · d(-1)) and ozone (O(3); ambient +10 ppb). Treatment of plants with sUV-B and O(3) , individually or in combination, caused several changes in enzymatic and non-enzymatic components of the antioxidant defence system. Photo-oxidative damage caused by sUV-B and O(3) , included lipid peroxidation, changed protein profiles and caused DNA strand breakage. One-dimensional gel electrophoresis revealed that proteins of 222.24 and 50.5 kDa are specific and appear after sUV-B and O(3) exposure, and could be used as indicator proteins. Effects of sUV-B and O(3) given separately are more detrimental as compared to combined treatment. Mutational and structural alterations in linseed DNA after these stresses were also examined using RAPD with ten different primers. The study concluded that both stresses, i.e. sUV-B and O(3) , are phytotoxic, causing significant changes in metabolites, antioxidants, the leaf proteome and the genome of linseed, but their interactive effect was always less than additive.

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A simple approach is proposed for obtaining low threshold field electron emission from large area diamond-like carbon (DLC) thin films by sandwiching either Ag dots or a thin Ag layer between DLC and nitrogen containing DLC films. The introduction of silver and nitrogen is found to reduce the threshold field for emission to under 6 V/m representing a near 46% reduction when compared with unmodified films. The reduction in the threshold field is correlated with the morphology, microstructure, interface and bonding environment of the films.We find modifications to the structure of the DLC films through promotion of metal-induced sp 2 bonding and the introduction of surface asperities, which significantly reduce the value of the threshold field. This can lead to the next generation large area simple and inexpensive field emission devices.