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Sample records for gelatinous drop-like corneal

  1. Gelatinous drop-like corneal dystrophy: a review.

    Science.gov (United States)

    Kaza, Hrishikesh; Barik, Manas R; Reddy, Mamatha M; Mittal, Ruchi; Das, Sujata

    2017-01-01

    Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive form of corneal dystrophy characterised by subepithelial and stromal amyloid deposits. It is relatively common in Japan. It usually presents in the first two decades of life with subepithelial nodular lesions that later coalesce to form mulberry-like opacities. Although various surgical modalities have been attempted, recurrence remains a major challenge.

  2. Limbal Stem Cell Transplantation for Gelatinous Drop-like Corneal Dystrophy

    Directory of Open Access Journals (Sweden)

    Hossein Movahedan

    2013-01-01

    Full Text Available Purpose: To report the outcomes of allograft limbal stem cell transplantation for recurrent gelatinous drop-like corneal dystrophy (GDLD. Methods: In this non-comparative interventional case series, 4 eyes of 3 consecutive patients with recurrent GDLD underwent allograft limbal stem cell transplantation. Two eyes underwent concomitant penetrating keratoplasty while the other two underwent simultaneous superficial keratectomy. Main outcome measures were best spectacle corrected visual acuity, intraocular pressure and corneal clarity. Results: Patient age ranged from 28 to 63 years. Mean follow-up after surgery was 23±10 (median, 22; range, 12-36 months. Mean visual acuity improved from 2.70±0.61 logMAR preoperatively to 1.05±0.06 logMAR at final postoperative visit (P=0.066. Intraocular pressure was normal in all eyes at baseline and remained within normal limits at all postoperative visits. All corneas remained smooth and clear during the follow-up period with no episode of rejection or recurrence. All patients maintained ambulatory vision until final follow-up. Conclusion: The present study provides further evidence that limbal stem cell transplantation may be an effective therapeutic alternative in patients with GDLD.

  3. Combined Excimer Laser Photoablation and Amniotic Membrane Overlay for Relief of Symptomatic Discomfort in Gelatinous Drop-like Corneal Dystrophy.

    Science.gov (United States)

    Alex, Anne F; Eter, Nicole; Uhlig, Constantin E

    2015-10-01

    To describe the efficacy of combined excimer laser photoablation and amniotic overlay membrane in the relief of symptomatic discomfort in a 17-year-old patient who had gelatinous drop-like corneal dystrophy. The best-corrected visual acuity (BCVA) was measured with Snellen letters. Slit-lamp examination of the ocular surface and anterior chamber was performed at baseline. Results were photodocumented. Excimer laser photoablation was performed and subsequently 2 amniotic membranes were transconjunctivally fixated with 10.0 nylon sutures. Investigations and documentation were performed at baseline, every 2 months in the first year, and then every 6 months. The duration of follow-up was 22 months. At baseline, the BCVA was 20/70 in the right eye and 20/200 in the left eye. The patient reported distinct photophobia. Slit-lamp examination was difficult because of blepharospasm. Although gelatinous drops developed again and the BCVA decreased to 2/200, the patient reported significant relief after both microsurgical treatments and remained comfortable at 20 and 22 months. Excimer laser photocoagulation combined with amniotic membrane overlay does not stop the development of gelatinous drop-like corneal dystrophy but may improve subjective comfort. Such treatment does not hinder subsequent lamellar or penetrating grafts and is helpful in providing the necessary time for preparation of matched keratoplasties.

  4. Electron microscopic studies of primary band-shaped keratopathy and gelatinous, drop-like corneal dystrophy in two brothers.

    Science.gov (United States)

    Kanai, A; Kaufman, H E

    1982-06-01

    We present here a case of bilateral primary band-shaped keratopathy that changed into a gelatinous, drop-like dystrophy over two years. To our knowledge, this is the first such case reported in the literature. In the first examination of the right eye, histologic evidence revealed no amyloid deposits and the presence of disorganized collagen lamellae with a high-density amorphous substance. The left corneal disc, obtained two years after the first and second examinations, revealed an agglomeration of amyloid fibrils in the subepithelial portion.

  5. Tissue engineering of corneal stroma with rabbit fibroblast precursors and gelatin hydrogels.

    Science.gov (United States)

    Mimura, Tatsuya; Amano, Shiro; Yokoo, Seiichi; Uchida, Saiko; Yamagami, Satoru; Usui, Tomohiko; Kimura, Yu; Tabata, Yasuhiko

    2008-01-01

    To isolate fibroblast precursors from rabbit corneal stroma using a sphere-forming assay, to engineer corneal stroma with the precursors and gelatin, and to establish the therapeutic application of precursors in a rabbit corneal stroma. In the in vitro study, a sphere-forming assay was performed to produce precursors from rabbit corneal stroma. Corneal stroma was engineered by cultivating precursors in porous gelatin for one week. In the in vivo study, the engineered corneal stromal sheet with precursors (precursor/gelatin group) or with fibroblasts (fibroblast /gelatin group) or without cells (gelatin group) was transplanted to a pocket of rabbit corneal stroma. Gene expression and extracellular matrix production were examined immunohistochemically in each group one week and four weeks after surgery. In the in vitro study, cells in the spheres were BrdU-positive, and their progeny were keratocan-positive. The study also showed that the corneas transplanted with a porous gelatin sheet did not show any opacity four weeks after transplantation in any group. In the gelatin sheet of the precursor/gelatin group, a more intense expression of type I collagen was observed relative to the other two groups four weeks after the surgery. Our findings demonstrate that the transplantation of fibroblast precursors combined with gelatin hydrogel into the corneal stroma is a possible treatment strategy for corneal stromal regeneration.

  6. Nanoscale modification of porous gelatin scaffolds with chondroitin sulfate for corneal stromal tissue engineering

    Directory of Open Access Journals (Sweden)

    Lai JY

    2012-02-01

    Full Text Available Jui-Yang Lai*, Ya-Ting Li*, Ching-Hsien Cho, Ting-Chun Yu Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan, Taiwan, Republic of China*These authors contributed equally to this workAbstract: Recent studies reflect the importance of using naturally occurring biopolymers as three-dimensional corneal keratocyte scaffolds and suggest that the porous structure of gelatin materials may play an important role in controlling nutrient uptake. In the current study, the authors further consider the application of carbodiimide cross-linked porous gelatin as an alternative to collagen for corneal stromal tissue engineering. The authors developed corneal keratocyte scaffolds by nanoscale modification of porous gelatin materials with chondroitin sulfate (CS using carbodiimide chemistry. Scanning electron microscopy/energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy showed that the amount of covalently incorporated polysaccharide was significantly increased when the CS concentration was increased from 0% to 1.25% (w/v. In addition, as demonstrated by dimethylmethylene blue assays, the CS content in these samples was in the range of 0.078–0.149 nmol per 10 mg scaffold. When compared with their counterparts without CS treatment, various CS-modified porous gelatin membranes exhibited higher levels of water content, light transmittance, and amount of permeated nutrients but possessed lower Young’s modulus and resistance against protease digestion. The hydrophilic and mechanical properties of scaffolds modified with 0.25% CS were comparable with those of native corneas. The samples from this group were biocompatible with the rabbit corneal keratocytes and showed enhanced proliferative and biosynthetic capacity of cultured cells. In summary, the authors found that the nanoscale-level modification has influence on the characteristics and cell-material interactions of CS-containing gelatin hydrogels

  7. Characterization of cross-linked porous gelatin carriers and their interaction with corneal endothelium: biopolymer concentration effect.

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    Jui-Yang Lai

    Full Text Available Cell sheet-mediated tissue regeneration is a promising approach for corneal reconstruction. However, the fragility of bioengineered corneal endothelial cell (CEC monolayers allows us to take advantage of cross-linked porous gelatin hydrogels as cell sheet carriers for intraocular delivery. The aim of this study was to further investigate the effects of biopolymer concentrations (5-15 wt% on the characteristic and safety of hydrogel discs fabricated by a simple stirring process combined with freeze-drying method. Results of scanning electron microscopy, porosity measurements, and ninhydrin assays showed that, with increasing solid content, the pore size, porosity, and cross-linking index of carbodiimide treated samples significantly decreased from 508±30 to 292±42 µm, 59.8±1.1 to 33.2±1.9%, and 56.2±1.6 to 34.3±1.8%, respectively. The variation in biopolymer concentrations and degrees of cross-linking greatly affects the Young's modulus and swelling ratio of the gelatin carriers. Differential scanning calorimetry measurements and glucose permeation studies indicated that for the samples with a highest solid content, the highest pore wall thickness and the lowest fraction of mobile water may inhibit solute transport. When the biopolymer concentration is in the range of 5-10 wt%, the hydrogels have high freezable water content (0.89-0.93 and concentration of permeated glucose (591.3-615.5 µg/ml. These features are beneficial to the in vitro cultivation of CECs without limiting proliferation and changing expression of ion channel and pump genes such as ATP1A1, VDAC2, and AQP1. In vivo studies by analyzing the rabbit CEC morphology and count also demonstrate that the implanted gelatin discs with the highest solid content may cause unfavorable tissue-material interactions. It is concluded that the characteristics of cross-linked porous gelatin hydrogel carriers and their triggered biological responses are in relation to biopolymer

  8. Liquid-drop-like model for cylindrical helium systems

    Science.gov (United States)

    Szybisz, Leszek

    2000-08-01

    Free liquid 4He at T=0 K with cylindrical symmetry is studied. The ground-state energy and chemical potential are computed by using a density functional approach. A liquid-drop-like model is formulated for analyzing the behavior of these observables as a function of the size of the systems. It is shown that such a model allows to get precise information about the asymptotic values of the energy per particle and surface tension.

  9. Fish gelatin.

    Science.gov (United States)

    Boran, Gokhan; Regenstein, Joe M

    2010-01-01

    Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed.

  10. Corneal Laceration

    Medline Plus

    Full Text Available ... Laceration? Corneal Laceration Diagnosis Corneal Laceration Treatment What Is Corneal Laceration? Written By: Daniel Porter Reviewed By: ... A Harrison MD Sep. 01, 2016 The cornea is the clear front window of the eye . A ...

  11. Starch gelatinization.

    Science.gov (United States)

    Ratnayake, Wajira S; Jackson, David S

    2009-01-01

    Starch occurs as highly organized structures, known as starch granules. Starch has unique thermal properties and functionality that have permitted its wide use in food products and industrial applications. When heated in water, starch undergoes a transition process, during which the granules break down into a mixture of polymers-in-solution, known as gelatinization. The sequence of structural transformations that the starch granule undergoes during this order-to-disorder transition has been extensively researched. None of the published starch gelatinization theories can fully and adequately explain the exact mechanism of sequential structural changes that starch granules undergo during gelatinization. This chapter analyzes several published theories and summarizes our current understanding of the starch gelatinization process.

  12. Corneal Laceration

    Medline Plus

    Full Text Available ... your vision. Privacy Policy Related People with Advanced Keratoconus May Have A Future Alternative to Full Corneal ... 2016 Corneal Collagen Cross-linking Approved to Treat Keratoconus in U.S. Aug 01, 2016 Firework Blinds Teenager, ...

  13. Corneal Laceration

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    Full Text Available ... lost sight from a corneal scar as a child. Now that I’m older, will a corneal transplant help me? May 15, 2015 Why Do My Eyes Burn After Inserting My Contacts? Feb 27, 2015 Dark ...

  14. Corneal Abrasions

    Science.gov (United States)

    ... and lead to a serious condition called a corneal ulcer . That's why it's important to see a doctor to get a corneal abrasion checked out. What Causes a Corneal ... and land on your cornea, tears help to wash the particles away. Sometimes, ...

  15. Corneal Laceration

    Science.gov (United States)

    ... drugs. These drugs thin the blood and may increase bleeding. After you have finished protecting the eye, see a physician immediately. Next Corneal Laceration Symptoms Related Ask an Ophthalmologist Answers I lost sight from a corneal scar as a child. Now that I’m older, ...

  16. Corneal Laceration

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    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué Es una Laceración de la Córnea? Written ...

  17. Corneal Laceration

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    Full Text Available ... Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask ... Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration Sections What Is Corneal Laceration? ...

  18. Corneal Laceration

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    Full Text Available ... Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask ... Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration Sections What Is Corneal Laceration? ...

  19. Corneal Laceration

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    Full Text Available ... from Laundry Packets On the Rise Jun 30, 2017 People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation Nov 29, 2016 Combating Eye Injuries from Air Guns Aug 30, ...

  20. Corneal transplant

    Science.gov (United States)

    ... lenses to achieve the best vision. Laser vision correction may be an option if you have nearsightedness, ... Editorial team. Related MedlinePlus Health Topics Corneal Disorders Refractive Errors Browse the Encyclopedia A.D.A.M., Inc. ...

  1. Corneal Laceration

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    Full Text Available ... Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide ... What Is Corneal Laceration? Leer en Español: ¿Qué ...

  2. Corneal Laceration

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    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... Dangerous for Your Eyes Sep 20, 2017 Eye Injuries from Laundry Packets On the Rise Jun 30, ...

  3. Corneal Laceration

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    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... 27, 2015 Dark Spot in Vision After Blunt Trauma Dec 21, 2014 Pain a Year After Eyelid ...

  4. Corneal Laceration

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    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... and preserving your vision. Privacy Policy Related Eye Injuries from Laundry Packets On the Rise Jun 30, ...

  5. Corneal Laceration

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    Full Text Available ... 2017 People with Advanced Keratoconus May Have A Future Alternative to Full Corneal Transplantation Nov 29, 2016 Combating Eye Injuries from Air Guns Aug 30, ... Public & Patients: Contact Us About ...

  6. Corneal Laceration

    Medline Plus

    Full Text Available ... by something sharp flying into the eye. It can also be caused by something striking the eye ... If the corneal laceration is deep enough it can cause a full thickness laceration. This is when ...

  7. Corneal Laceration

    Medline Plus

    Full Text Available ... Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide ... What Is Corneal Laceration? Written By: Daniel Porter ...

  8. Corneal Laceration

    Medline Plus

    Full Text Available ... By: Devin A Harrison MD Sep. 01, 2017 The cornea is the clear front window of the eye . A corneal laceration is a cut on the cornea. It is usually caused by something sharp ...

  9. Corneal Laceration

    Medline Plus

    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... 27, 2015 Dark Spot in Vision After Blunt Trauma Dec 21, 2014 Pain a Year After Eyelid ...

  10. Corneal Transplantation

    DEFF Research Database (Denmark)

    Hjortdal, Jesper Østergaard

    Corneal transplantation has been performed for more than 100 years. Until 15 years ago the state-of-the art type of transplantation was penetrating keratoplasty, but since the start of this millennium, newly designed surgical techniques have developed considerably. Today, the vast majority of ker...

  11. Corneal Laceration

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    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... After Eyelid Scratch Jul 28, 2014 Leer en Español: ¿Qué Es una Laceración de la Córnea? Find ...

  12. Corneal topography

    DEFF Research Database (Denmark)

    Andersen, J.; Koch-Jensen, P.; Østerby, Ole

    1993-01-01

    The central corneal zone is depicted on keratoscope photographs using a small target aperture and a large object distance. Information on the peripheral area is included by employing a hemispherical target with a dense circular and radial pattern. On a 16 mm (R = 8 mm) reference steel sphere...

  13. Corneal chromoblastomycosis.

    Science.gov (United States)

    Barton, K; Miller, D; Pflugfelder, S C

    1997-03-01

    We sought to illustrate the difficulty in managing uncommon, pigmented mold-related corneal ulceration and to highlight the role of itraconazole in treating these patients. We describe the management and clinical course of a patient with a recurring corneal infection caused by Fonsecaea pedrosoi and discuss this experience in the light of existing literature on management of cutaneous chromoblastomycosis. A corneal ulcer caused by this organism healed initially on treatment with topical and systemic antifungal medication, but infection recurred in the deep stroma 4 months after cessation of therapy. After failure to respond to a further period of medical therapy, a small therapeutic penetrating keratoplasty was performed. Culture of a fibrinous membrane from the anterior iris surface demonstrated intraocular fungal infection, and postoperatively, an episode of marked fibrinous uveitis developed, suggesting the presence of viable intraocular fungal elements. A large penetrating keratoplasty was therefore performed with excision of involved iris in combination with extracapsular cataract extraction. F. pedrosoi was again cultured from the fibrinous membrane adherent to the iris and from the anterior lens capsule. Postoperatively the patient received a 5-month course of systemic itraconazole, and no further recurrences have been encountered after a further 2 months. F. pedrosoi is the organism most commonly isolated from the chronic cutaneous mycosis, chromoblastomycosis, and is relatively resistant to medical therapy. As has been reported for cutaneous disease, surgery in combination with systemic itraconazole may provide the best chance of cure in corneal chromoblastomycosis.

  14. Feline corneal disease.

    Science.gov (United States)

    Moore, Phillip Anthony

    2005-05-01

    The cornea is naturally transparent. Anything that interferes with the cornea's stromal architecture, contributes to blood vessel migration, increases corneal pigmentation, or predisposes to corneal edema, disrupts the corneas transparency and indicates corneal disease. The color, location, and shape and pattern of a corneal lesion can help in determining the underlying cause for the disease. Corneal disease is typically divided into congenital or acquired disorders. Congenital disorders, such as corneal dermoids are rare in cats, whereas acquired corneal disease associated with nonulcerative or ulcerative keratitis is common. Primary ocular disease, such as tear film instability, adenexal disease (medial canthal entropion, lagophthalmus, eyelid agenesis), and herpes keratitis are associated with the majority of acquired corneal disease in cats. Proliferative/eosinophilic keratitis, acute bullous keratopathy, and Florida keratopathy are common feline nonulcerative disorders. Nonprogressive ulcerative disease in cats, such as chronic corneal epithelial defects and corneal sequestration are more common than progressive corneal ulcerations.

  15. Equine corneal stromal abscesses

    DEFF Research Database (Denmark)

    Henriksen, M. D. L.; Andersen, P. H.; Plummer, C. E.

    2013-01-01

    The last 30 years have seen many changes in the understanding of the pathogenesis and treatment of equine corneal stromal abscesses (SAs). Stromal abscesses were previously considered an eye problem related to corneal bacterial infection, equine recurrent uveitis, corneal microtrauma and corneal...

  16. Corneal ulcers in horses.

    Science.gov (United States)

    Williams, Lynn B; Pinard, Chantale L

    2013-01-01

    Corneal ulceration is commonly diagnosed by equine veterinarians. A complete ophthalmic examination as well as fluorescein staining, corneal cytology, and corneal bacterial (aerobic) and fungal culture and sensitivity testing are necessary for all infected corneal ulcers. Appropriate topical antibiotics, topical atropine, and systemic NSAIDs are indicated for all corneal ulcers. If keratomalacia (melting) is observed, anticollagenase/antiprotease therapy, such as autologous serum, is indicated. If fungal infection is suspected, antifungal therapy is a necessity. Subpalpebral lavage systems allow convenient, frequent, and potentially long-term therapy. Referral corneal surgeries provide additional therapeutic options when the globe's integrity is threatened or when improvement has not been detected after appropriate therapy.

  17. Corneal transplant - discharge

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000243.htm Corneal transplant - discharge To use the sharing features on this page, please enable JavaScript. You had a corneal transplant. Most of the tissue of your cornea (the ...

  18. Wave propagation in ballistic gelatine.

    Science.gov (United States)

    Naarayan, Srinivasan S; Subhash, Ghatu

    2017-01-23

    Wave propagation characteristics in long cylindrical specimens of ballistic gelatine have been investigated using a high speed digital camera and hyper elastic constitutive models. The induced transient deformation is modelled with strain rate dependent Mooney-Rivlin parameters which are determined by modelling the stress-strain response of gelatine at a range of strain rates. The varying velocity of wave propagation through the gelatine cylinder is derived as a function of prestress or stretch in the gelatine specimen. A finite element analysis is conducted using the above constitutive model by suitably defining the impulse imparted by the polymer bar into the gelatine specimen. The model results are found to capture the experimentally observed wave propagation characteristics in gelatine effectively.

  19. Molecular mechanism of the inhibition effect of Lipoxin A4 on corneal dissolving pathology process

    Directory of Open Access Journals (Sweden)

    Hong-Yan Zhou

    2013-02-01

    Full Text Available AIM: Excessive dissolve of corneal tissue induced by MMPs which were activated by cytokins and chemokines will lead to corneal ulcer. The molecular mechanism of Lipoxin A4 (LXA4 on corneal collagen degradation in three dimensions was investigated.METHODS:Rabbit corneal fibroblasts were harvested and suspended in serum-free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidified in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP-1, -3 and TMMP-1,-2 was performed. MMP-2,-9 was detected by the method of Gelatin zymography. Cytotoxicity assay was measured.RESULTS:LXA4 inhibited corneal collagen degradation in a dose and time manner. LXA4 inhibited the IL-1β induced increases in the pro-MMP-1, -2, -3, -9 and active MMP-1, -2, -3, -9 in a concentration dependent manner. LXA4 could also inhibit the IL-1β induced increases in TIMP-1, -2.CONCLUSION: As a potent anti-inflammation reagent, LXA4 can inhibit corneal collagen degradation induced by IL-1β in corneal fibroblasts thus inhibiting corneal dissolving pathology process.

  20. Corneal mucus plaques.

    Science.gov (United States)

    Fraunfelder, F T; Wright, P; Tripathi, R C

    1977-02-01

    Corneal mucus plaques adhered to the anterior corneal surface in 17 of 67 advanced cases of keratoconjunctivitis sicca. The plaques were translucent to opaque and varied in size and shape, from multiple isolated islands to bizarre patterns involving more than half the corneal surface. Ultrastructurally, they consisted of mucus mixed with desquamated degenerating epithelial cells and proteinaceous and lipoidal material. The condition may be symptomatic but can be controlled and prevented in most cases by topical ocular application of 10% acetylcysteine.

  1. Modification of gelatin-DNA interaction for optimised DNA extraction from gelatin and gelatin capsule.

    Science.gov (United States)

    Mohamad, Nurhidayatul Asma; Mustafa, Shuhaimi; El Sheikha, Aly Farag; Khairil Mokhtar, Nur Fadhilah; Ismail, Amin; Ali, Md Eaqub

    2016-05-01

    Poor quality and quantity of DNA extracted from gelatin and gelatin capsules often causes failure in the determination of animal species using PCR. Gelatin, which is mainly derived from porcine and bovine, has been a matter of concern among customers in order to fulfill religious obligation and safety precaution against several transmissible infectious diseases associated with bovine species. Thus, optimised DNA extraction from gelatin is very important for successful real-time PCR detection of gelatin species. In this work, the DNA extraction method was optimised in terms of lysis incubation period and inclusion of pre-treatment pH modification of samples. The yield of DNA extracted from porcine gelatin was significantly increased when the pH of the samples was adjusted to pH 8.5 prior to DNA precipitation with isopropanol. The optimal pH for DNA precipitation from bovine gelatin solution was then determined at the original pH range of solution: pH 7.6 to 8. A DNA fragment of approximately 300 base pairs was available for PCR amplification. DNA extracted from gelatin and commercially available capsules has been successfully utilised for species detection using real-time PCR assay. However, significant adulterations of porcine and bovine in pure gelatin and capsules have been detected, which require further analytical techniques for validation. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  2. Characterization of Corneal Indentation Hysteresis.

    Science.gov (United States)

    Ko, Match W L; Dongming Wei; Leung, Christopher K S

    2015-01-01

    Corneal indentation is adapted for the design and development of a characterization method for corneal hysteresis behavior - Corneal Indentation Hysteresis (CIH). Fourteen porcine eyes were tested using the corneal indentation method. The CIH measured in enucleated porcine eyes showed indentation rate and intraocular pressure (IOP) dependences. The CIH increased with indentation rate at lower IOP ( 25 mmHg). The CIH was linear proportional to the IOP within an individual eye. The CIH was positively correlated with the IOP, corneal in-plane tensile stress and corneal tangent modulus (E). A new method based on corneal indentation for the measurement of Corneal Indentation Hysteresis in vivo is developed. To our knowledge, this is the first study to introduce the corneal indentation hysteresis and correlate the corneal indentation hysteresis and corneal tangent modulus.

  3. SYNERESIS AND SWELLING OF GELATIN.

    Science.gov (United States)

    Kunitz, M

    1928-11-20

    1. When solid blocks of isoelectric gelatin are placed in cold distilled water or dilute buffer of pH 4.7, only those of a gelatin content of more than 10 per cent swell, while those of a lower gelatin content not only do not swell but actually lose water. 2. The final quantity of water lost by blocks of dilute gelatin is the same whether the block is immersed in a large volume of water or whether syneresis has been initiated in the gel through mechanical forces such as shaking, pressure, etc., even in the absence of any outside liquid, thus showing that syneresis is identical with the process of negative swelling of dilute gels when placed in cold water, and may be used as a convenient term for it. 3. Acid- or alkali-containing gels give rise to greater syneresis than isoelectric gels, after the acid or alkali has been removed by dialysis. 4. Salt-containing gels show greater syneresis than salt-free gels of the same pH, after the salt has been washed away. 5. The acid and alkali and also the salt effect on syneresis of gels disappears at a gelatin concentration above 8 per cent. 6. The striking similarity in the behavior of gels with respect to syneresis and of gelatin solutions with respect to viscosity suggests the probability that both are due to the same mechanism, namely the mechanism of hydration of the micellae in gelatin by means of osmosis as brought about either by diffusible ions, as in the presence of acid or alkali, or by the soluble gelatin present in the micellae. The greater the pressures that caused swelling of the micellae while the gelatin was in the sol state, the greater is the loss of water from the gels when the pressures are removed. 7. A quantitative study of the loss of water by dilute gels of various gelatin content shows that the same laws which have been found by Northrop to hold for the swelling of gels of high concentrations apply also to the process of losing water by dilute gels, i.e. to the process of syneresis. The general

  4. Current status of corneal xenotransplantation.

    Science.gov (United States)

    Kim, Mee Kum; Hara, Hidetaka

    2015-11-01

    Corneal allo-transplantation is a well-established technique to treat corneal blindness. However, the limited availability of human donors demands the exploration of alternative treatments such as corneal xenotransplantation (e.g., pigs as donors) and bioengineered corneas. Since the first attempt of corneal xenotransplantation using a donor pig cornea in 1844, great advances have been made in the development of genetically-engineered pigs, effective immunosuppressive protocols and the establishment of guidelines for the conduction of clinical trials. We highlight immunological and physio-anatomical barriers of corneal xenotransplantation, recent progress of corneal xenotransplantation in non-human-primates studies, and regulatory guidelines to conduct clinical trials for corneal xenotransplantation.

  5. Corneal blindness and xenotransplantation.

    Science.gov (United States)

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K C

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

  6. Refractive corneal surgery - discharge

    Science.gov (United States)

    Nearsightedness surgery - discharge; Refractive surgery - discharge; LASIK - discharge; PRK - discharge ... You had refractive corneal surgery to help improve your vision. This surgery uses a laser to reshape your cornea. It corrects mild-to-moderate nearsightedness, ...

  7. Equine corneal surgery and transplantation.

    Science.gov (United States)

    Denis, Heidi M

    2004-08-01

    Corneal disease is common in equine ophthalmology and requires vigilant monitoring and appropriate therapy to optimize the outcome. Many equine corneal diseases, particularly those that progress rapidly, may benefit from surgical intervention. These include descemetoceles, deep corneal lacerations and ulcers, corneal perforation/iris prolapse, ulcerative keratitis, corneal stromal abscesses, and corneoscleral neoplasia. Indications for corneal transplantation include optical, tectonic, therapeutic, and cosmetic purposes. Corneal transplantation is most often implemented in equine patients for tectonic and therapeutic reasons when a cornea is compromised by corneal stromal abscess, iris prolapse, or neoplasia. This article provides an outline of when to consider surgical intervention for corneal disease, the procedures available and expected outcomes, and how appropriate early surgical intervention can dramatically improve the end result.

  8. Central corneal abscess.

    Science.gov (United States)

    van Bijsterveld, O P

    1976-05-01

    Central corneal abscess developed in the experimental animal after inoculation of biologically active staphylococcal strains in a paracentral epithelial lesion of the cornea. These abscesses did not ulcerate, developed only with high inocula, occurred more frequently in immunized rabbits. A serpiginous type of ulceration did not develop at the site of the initial epithelial lesion nor at any other place in the cornea. Histologically, the lesions consisted of densely packed polymorphonuclear leukocytes between the corneal lamellae.

  9. Effects of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell counts.

    Science.gov (United States)

    Gao, Feng; Lin, Tao; Pan, Yingzhe

    2016-09-01

    Diabetic keratopathy is an ocular complication that occurs with diabetes. In the present study, the effect of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell count was investigated. One hundred and eighty diabetic patients (360 eyes) were enrolled in the study during the period from March, 2012 to March, 2013. The patients were divided into three age groups: 10 years, with 60 patients per group (120 eyes). During the same period, 60 healthy cases (120 eyes) were selected and labeled as the normal control group. The Pentacam was used to measure the corneal optical density, and central corneal thickness. Specular microscopy was used to examine the corneal endothelial cell density. The coefficient of partial correlation was used to control age and correlate the analysis between the corneal optical density, corneal endothelial cell density, and central corneal thickness. The stage of the disease, the medial and intimal corneal optical density and central corneal thickness was analyzed in the diabetes group. The corneal optical density in the diabetes group increased compared with that of the normal control group. The medial and intimal corneal optical density and central corneal thickness were positively correlated with the course of the disease. However, the corneal endothelial cell density was not associated with the course of diabetes. There was a positive association between the medial and intimal corneal optical density and central corneal thickness of the diabetic patients. In conclusion, the results of the present study show that medial and intimal corneal optical density and central corneal thickness were sensitive indicators for early diabetic keratopathy.

  10. A corneal mold to restore normal corneal dimensions.

    Science.gov (United States)

    Swinger, C A; Kornmehl, E W; York, S; Forman, J S

    1986-01-01

    A corneal mold is described that provides an MK corneal button of normal thickness and curvature from an edematous, post-mortem button. The uniform, processed tissue can then be used for experimental refractive surgery.

  11. Inhibition by all-trans retinoic acid of collagen degradation mediated by corneal fibroblasts.

    Science.gov (United States)

    Kimura, Kazuhiro; Zhou, Hongyan; Orita, Tomoko; Kobayashi, Shinya; Wada, Tomoyuki; Nakamura, Yoshikuni; Nishida, Teruo; Sonoda, Koh-Hei

    2016-08-01

    We examined the effect of all-trans retinoic acid on collagen degradation mediated by corneal fibroblasts. Rabbit corneal fibroblasts were cultured with or without all-trans retinoic acid in a three-dimensional collagen gel, and the extent of collagen degradation was determined by measurement of hydroxyproline in acid hydrolysates of culture supernatants. Matrix metalloproteinase expression was examined by immunoblot analysis and gelatin zymography. The abundance and phosphorylation state of the endogenous nuclear factor-kappaB inhibitor IκB-α were examined by immunoblot analysis. Corneal ulceration was induced by injection of lipopolysaccharide into the central corneal stroma of rabbits and was assessed by observation with a slitlamp microscope. All-trans retinoic acid inhibited interleukin-1β-induced collagen degradation by corneal fibroblasts in a concentration- and time-dependent manner. It also attenuated the release and activation of matrix metalloproteinases as well as the phosphorylation and degradation of IκB-α induced by interleukin-1β in these cells. Topical application of all-trans retinoic acid suppressed corneal ulceration induced by injection of lipopolysaccharide into the corneal stroma. All-trans retinoic acid inhibited collagen degradation mediated by corneal fibroblasts exposed to interleukin-1β, with this effect being accompanied by suppression of nuclear factor-kappaB signalling as well as of matrix metalloproteinase release and activation in these cells. All-trans retinoic acid also attenuated lipopolysaccharide-induced corneal ulceration in vivo. Our results therefore suggest that all-trans retinoic acid might prove effective for the treatment of patients with corneal ulceration. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  12. Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats.

    Science.gov (United States)

    Lakshminarayanan, Rajamani; Sridhar, Radhakrishnan; Loh, Xian Jun; Nandhakumar, Muruganantham; Barathi, Veluchamy Amutha; Kalaipriya, Madhaiyan; Kwan, Jia Lin; Liu, Shou Ping; Beuerman, Roger Wilmer; Ramakrishna, Seeram

    2014-01-01

    Topical application of antifungals does not have predictable or well-controlled release characteristics and requires reapplication to achieve therapeutic local concentration in a reasonable time period. In this article, the efficacy of five different US Food and Drug Administration-approved antifungal-loaded (amphotericin B, natamycin, terbinafine, fluconazole, and itraconazole) electrospun gelatin fiber mats were compared. Morphological studies show that incorporation of polyenes resulted in a two-fold increase in fiber diameter and the mats inhibit the growth of yeasts and filamentous fungal pathogens. Terbinafine-loaded mats were effective against three filamentous fungal species. Among the two azole antifungals compared, the itraconazole-loaded mat was potent against Aspergillus strains. However, activity loss was observed for fluconazole-loaded mats against all of the test organisms. The polyene-loaded mats displayed rapid candidacidal activities as well. Biophysical and rheological measurements indicate strong interactions between polyene antifungals and gelatin matrix. As a result, the polyenes stabilized the triple helical conformation of gelatin and the presence of gelatin decreased the hemolytic activity of polyenes. The polyene-loaded fiber mats were noncytotoxic to primary human corneal and sclera fibroblasts. The reduction of toxicity with complete retention of activity of the polyene antifungal-loaded gelatin fiber mats can provide new opportunities in the management of superficial skin infections.

  13. Starch gelatinization under thermal stress.

    Science.gov (United States)

    Faroongsarng, D; Wongpoowarak, W; Mitrevej, A

    1999-01-01

    The behavior under thermal stress of starch dispersed in water was studied by differential scanning calorimetry (DSC) to estimate the heat transported through the aqueous medium in gelatinization, and to characterize the range of gelatinization temperatures. In DSC scanning mode, the endotherm of 10% starch in aqueous dispersion showed the tracing of gelatinization at between 67 and 80 degrees C, having an onset at approximately 69 degrees C. In the isothermal mode, characteristically distinct isothermal heat flow profiles were revealed. It was hypothesized that the thermal influx proposed as being analogous to the diffusion process may affect the profiles. The profiles were transformed and nonlinearly fitted according to the square root of time model to characterize a so-called t-parameter, which was related to mean square displacement of molecular distribution. The t-parameter of starch in excess of water decreased compared to that of water only. The plot of difference in these t-parameters, expressed as delta, against temperature showed a dramatically decreased delta at the temperature between 66.7 and 75.2 degrees C, which coincided with the findings from scanning mode DSC. It was further hypothesized that the decreased delta may be due to the gelatinizing process. According to the theory of polymer solution, the critical temperature (theta) at 75.2 degrees C, where the free energy became theoretically negative, i.e., the starch became spontaneously dissolved, was drawn. This theta was located within the range of gelatinizing temperatures. It was deduced that starch polymer may have dissolved during gelatinization. The dissolution from acetaminophen tablets prepared by starch paste was lower compared with that of negative controls (without paste). Moreover, the paste prepared at gelatinizing temperature (70 degrees C) seemed to inhibit acetaminophen dissolution from tablet matrices more than that prepared at subgelatinizing temperature (50 degrees C).

  14. Corneal Topography Analysis of Stromal Corneal Dystrophies

    OpenAIRE

    Kocluk, Yusuf; Yalniz-Akkaya, Zuleyha; Burcu, Ayse; Ornek, Firdevs

    2015-01-01

    Objective: The aim was to compare the corneal topography and tomography parameters of macular corneal dystrophy (MCD), granular corneal dystrophy (GCD) and lattice corneal dystrophy (LCD) patients obtained by Scheimpflug imaging system. Methods: The charts, photographs and topography images of patients were reviewed retrospectively. This study included 73 eyes of 73 patients (28 MCD, 20 GCG and 25 LCD patients). Topography images were obtained by Pentacam (Oculus Optikgerate, Wetzlar, Germany...

  15. [Corneal sensibility following epikeratophakia].

    Science.gov (United States)

    Biermann, H; Grabner, G; Baumgartner, I; Reim, M

    1992-07-01

    The postoperative rate of reinnervation following corneal surgery is widely considered to be a useful indicator of the healing process. This study reports the corneal sensitivity of 14 patients following epikeratophakia for different indications (myopia, aphakia and keratoconus) after time periods ranging from 7 to 104 weeks. All transplants were clear at the time of measurement. A newly developed aesthesiometer (using a low electric current for stimulation) was employed. Nine positions on the operated eye were chosen for the measurements, five locations of the non-operated fellow eye served as controls. On the operated eye the corneal sensitivity peripheral to the trephination were significantly reduced at the 9 and 12 o'clock positions as compared to the other eye. The 3 and 6 o'clock locations showed no significant difference. On the epikeratophakia lenticule the sensitivity was significantly reduced at all points, the center showing the largest difference (p less than 0.001). No correlation with age, sex or the indication for the procedure was observed. Although there was a trend of a positive correlation between the postoperative time period and the central corneal sensitivity, the follow-up was too short to reach significant levels. The nearly complete lack of corneal sensitivity, particularly in the center of the transplant is therefore well compatible with its long-time survival, even when the lenticule has been prepared with the cryolathe and lyophilized for transportation.

  16. Antifibrotic effect by activation of peroxisome proliferator-activated receptor-gamma in corneal fibroblasts.

    Science.gov (United States)

    Pan, Hongwei; Chen, Jiansu; Xu, Jintang; Chen, Miaojiao; Ma, Rong

    2009-11-10

    The transformation of quiescent keratocytes to active phenotypes and the ensuing fibrotic response play important roles in corneal scar formation. This study aims to observe the antifibrotic effect of peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist on corneal fibroblasts cultured in vitro, and to explore the potential application of peroxisome proliferator-activated receptor agonist to the prevention of corneal opacity following wound repair. Rabbit corneal keratocytes were cultured in a medium containing 10% serum to induce their transformation to fibroblasts and myofibroblasts, which are similar to those that repair corneas. After incubation with the PPARgamma agonist pioglitazone at different concentrations, the effect of pioglitazone on the migration, contractility, and viability of corneal fibroblasts was examined. The secretion of matrix metalloproteinase-2 and matrix metalloproteinase-9 was determined by gelatin zymography, and the synthesis of collagen I and fibronectin was investigated by western blotting. Treatment with pioglitazone at concentrations ranging from 1 to 10 mum significantly decreased corneal fibroblast migration, as determined by scrape-wound assay, inhibited corneal fibroblast-induced collagen lattice contraction, and reduced MMP-2 and MMP-9 secretion into the supernatant of cell cultures in a dose-dependent manner. The expression of fibronectin was significantly decreased, while the expression of collagen I was only decreased when treated with 10 mum pioglitazone. Cell viability was not evidently changed compared to the control. This in vitro study demonstrated the anti-fibrotic effect of pioglitazone, suggesting that activation of PPARgamma may be a new approach for the treatment of corneal opacity and scar formation in the corneal wound healing process.

  17. Inhibition by female sex hormones of collagen degradation by corneal fibroblasts.

    Science.gov (United States)

    Zhou, Hongyan; Kimura, Kazuhiro; Orita, Tomoko; Nishida, Teruo; Sonoda, Koh-Hei

    2011-01-01

    Corneal fibroblasts contribute to collagen remodeling in the corneal stroma in part by mediating collagen degradation. Given that corneal structure is influenced by sex hormone status, we examined the effects of sex hormones on collagen degradation by corneal fibroblasts. Rabbit corneal fibroblasts were cultured in three-dimensional collagen gels with or without sex hormones including 17β-estradiol, progesterone, testosterone, and dehydroepiandrosterone (DHEA). Collagen degradation was determined by measurement of hydroxyproline after acid hydrolysis. The expression and activity of matrix metalloproteinases (MMPs) were evaluated by immunoblot analysis and gelatin zymography. The phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappa B (NF-κB) inhibitor NF kappa B Inhibitor-alpha (IκB-α) in corneal fibroblasts was examined by immunoblot analysis. Cell proliferation and viability were evaluated by measurement of bromodeoxyuridine incorporation and the release of lactate dehydrogenase, respectively. 17β-Estradiol and progesterone each inhibited interleukin (IL)-1β-induced collagen degradation by corneal fibroblasts in a concentration-dependent manner, whereas testosterone and DHEA had no such effect. MMP expression and activation in corneal fibroblasts exposed to IL-1β were also inhibited by 17β-estradiol and progesterone. These female sex hormones did not affect cell proliferation or viability. Both 17β-estradiol and progesterone inhibited the IL-1β-induced phosphorylation of p38 MAPK without affecting that of the MAPKs extracellular Signal-regulated Kinase (ERK) or c-jun N-terminal kinase (JNK). 17β-Estradiol also inhibited the IL-1β-induced phosphorylation of IκB-α. 17β-Estradiol and progesterone inhibited MMP expression and activity in IL-1β-stimulated corneal fibroblasts and thereby suppressed collagen degradation by these cells.

  18. Review: gelatin, source, extraction and industrial applications

    Directory of Open Access Journals (Sweden)

    Abdalbasit Adam Mariod

    2013-06-01

    Full Text Available Gelatin is an important functional biopolymer widely used in foods to improve elasticity, consistency, and stability. It can be obtained not only from the skin and bones of land animals, but also from fish and insects. In recent years gelatins from fish and edible insects provide an alternative source that is acceptable for halal (Muslim and kosher (Jewish products, gelatin extraction has been reported for different fishes and insects. In gelatin manufacture, two methods are usually used: the acid and the alkaline processes, to produce type A and type B gelatins, respectively.  

  19. Inhibition by medroxyprogesterone acetate of interleukin-1β-induced collagen degradation by corneal fibroblasts.

    Science.gov (United States)

    Zhou, Hongyan; Kimura, Kazuhiro; Orita, Tomoko; Nishida, Teruo; Sonoda, Koh-Hei

    2012-06-28

    To examine the effect of medroxyprogesterone 17-acetate (MPA) on interleukin-1β (IL-1β)-induced collagen degradation by corneal fibroblasts. Rabbit corneal fibroblasts were cultured in three-dimensional collagen gels with or without MPA. Collagen degradation was determined by measurement of hydroxyproline after acid hydrolysis. The expression or activity of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) was evaluated by immunoblot analysis or gelatin zymography. The phosphorylation of mitogen-activated protein kinases (MAPKs) in corneal fibroblasts was examined by immunoblot analysis. Cell proliferation and viability were evaluated by measurement of bromodeoxyuridine incorporation and the release of lactate dehydrogenase, respectively. MPA inhibited IL-1β-induced collagen degradation by corneal fibroblasts in a concentration- and time-dependent manner. MMP expression and activation as well as TIMP expression in corneal fibroblasts exposed to IL-1β were also inhibited by MPA. MPA had no effect on cell proliferation or viability. MPA inhibited the IL-1β-induced phosphorylation of p38 MAPK without affecting that of the MAPKs ERK or JNK. IL-1β-induced MMP expression and activation as well as collagen degradation were also blocked by the p38 MAPK inhibitor SB203580. MPA inhibited MMP expression and thereby suppressed collagen degradation by corneal fibroblasts induced by IL-1β. Furthermore, inhibition of p38 MAPK phosphorylation by MPA may contribute to its inhibition of collagen degradation.

  20. Gelatin and Non-Gelatin Capsule Dosage Forms.

    Science.gov (United States)

    Gullapalli, Rampurna P; Mazzitelli, Carolyn L

    2017-06-01

    Capsules offer an alternate to tablets for oral delivery of therapeutic compounds. One advantage of capsules over tablets is their amenability to deliver not only solids but also nonaqueous liquids and semisolids as a unit dose solid dosage form. Shell component is an essential part of capsule dosage forms. Capsule shells, available as hard or soft shells, are formulated from gelatin or a non-gelatin polymeric material such as hypromellose and starch, water, and with or without a nonvolatile plasticizer. The capsule shells may also be formulated to modify the release of their fill contents in a site-specific manner in the gastrointestinal tract. The goal of the current review is to provide an in-depth discussion on polymeric film-forming materials and manufacturing technologies used in the production of capsule shells. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  1. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    OpenAIRE

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Topical application of benzalkonium chloride (BAK) to the eye causes dose-related corneal neurotoxicity. Corneal inflammation and reduction in aqueous tear production accompany neurotoxicity. Cessation of BAK treatment leads to recovery of corneal nerve density.

  2. Genetics of corneal endothelial dystrophies

    Indian Academy of Sciences (India)

    Chitra Kannabiran

    2009-12-01

    The corneal endothelium maintains the level of hydration in the cornea. Dysfunction of the endothelium results in excess accumulation of water in the corneal stroma, leading to swelling of the stroma and loss of transparency. There are four different corneal endothelial dystrophies that are hereditary, progressive, non-inflammatory disorders involving dysfunction of the corneal endothelium. Each of the endothelial dystrophies is genetically heterogeneous with different modes of transmission and/or different genes involved in each subtype. Genes responsible for disease have been identified for only a subset of corneal endothelial dystrophies. Knowledge of genes involved and their function in the corneal endothelium can aid understanding the pathogenesis of the disorder as well as reveal pathways that are important for normal functioning of the endothelium.

  3. Bilateral acute corneal calcification.

    Science.gov (United States)

    Freddo, T F; Leibowitz, H M

    1985-04-01

    A 38-year-old man with brittle, juvenile onset diabetes mellitus and bilateral severe dry eyes with recurrent corneal ulcers developed atypical band-shaped calcifications of both corneas during a 24-hour period. Serum calcium, phosphate, and carbon dioxide levels all were within normal limits. The patient was mildly uremic but was not in renal failure. When EDTA chelation failed to clear the deposits, partial keratectomies were performed in both eyes and the specimens were examined by light and electron microscopy, including energy dispersive x-ray analysis. Microscopic studies revealed an atypical calcific keratopathy which involved neither Bowman's layer nor the most superficial stromal lamellae. The deposits were confined to deeper lamellae in the anterior stroma and by electron microscopy were composed of extracellular crystalline aggregates. Energy dispersive x-ray analysis of these aggregates confirmed the presence of calcium and phosphate. Corneal dessication appeared to be a major contributing factor in the rapid formation of these deposits.

  4. Starch gelatinization in coiled heaters.

    Science.gov (United States)

    Kelder, J D H; Ptasinski, K J; Kerkhof, P J A M

    2004-01-01

    A gelatinizing model food derived from a 5% w/w cross-linked waxy maize starch suspension was simulated in coiled heaters to assess the impact of centrifugal forces on flow and heat transfer. For four coil diameters (D = 0.25, 1, 2.5, and infinity m) and three flow rates (w = 0.5, 1, and 2 m/s), heat transfer, viscous development, and the severity of channeling were evaluated. Increasing curvature proved to suppress channeling as a result of more uniform heating and gelatinization. The maximum attainable viscosity was also higher, implying a lower starch consumption for a target viscosity. Higher flow rates necessitated longer heaters, and the maximum viscosity decreased. Moderate product velocities are therefore recommended.

  5. Multilayered Magnetic Gelatin Membrane Scaffolds

    Science.gov (United States)

    Samal, Sangram K.; Goranov, Vitaly; Dash, Mamoni; Russo, Alessandro; Shelyakova, Tatiana; Graziosi, Patrizio; Lungaro, Lisa; Riminucci, Alberto; Uhlarz, Marc; Bañobre-López, Manuel; Rivas, Jose; Herrmannsdörfer, Thomas; Rajadas, Jayakumar; De Smedt, Stefaan; Braeckmans, Kevin; Kaplan, David L.; Dediu, V. Alek

    2016-01-01

    A versatile approach for the design and fabrication of multilayer magnetic scaffolds with tunable magnetic gradients is described. Multilayer magnetic gelatin membrane scaffolds with intrinsic magnetic gradients were designed to encapsulate magnetized bioagents under an externally applied magnetic field for use in magnetic-field-assisted tissue engineering. The temperature of the individual membranes increased up to 43.7 °C under an applied oscillating magnetic field for 70 s by magnetic hyperthermia, enabling the possibility of inducing a thermal gradient inside the final 3D multilayer magnetic scaffolds. On the basis of finite element method simulations, magnetic gelatin membranes with different concentrations of magnetic nanoparticles were assembled into 3D multilayered scaffolds. A magnetic-gradient-controlled distribution of magnetically labeled stem cells was demonstrated in vitro. This magnetic biomaterial–magnetic cell strategy can be expanded to a number of different magnetic biomaterials for various tissue engineering applications. PMID:26451743

  6. Corneal blindness: prevention, treatment and rehabilitation

    Directory of Open Access Journals (Sweden)

    Matthew J Burton

    2009-12-01

    Full Text Available Blindness from corneal disease is a major ophthalmic public health problem. There are three important elements to addressing corneal blindness: prevention, treatment, and rehabilitation.

  7. Gelatinous plankton: irregularities rule the world (sometimes)

    OpenAIRE

    Boero, F.; Bouillon, J; GRAVILI C.; Miglietta, M. P.; Parsons, T. R.; Piraino, S.

    2008-01-01

    In spite of being one of the most relevant components of the biosphere, the plankton-benthos network is still poorly studied as such. This is partly due to the irregular occurrence of driving phenomena such as gelatinous plankton pulses in this realm. Gelatinous plankters rely on their life cycles and histories to exploit temporarily abundant resources with an undeniable, but often overlooked, impact on marine food webs. Dramatic increases of gelatinous filter-feeders and/or carnivores (both ...

  8. [Gelatinous transformation of the bone marrow].

    Science.gov (United States)

    Kemona, A; Dziecioł, J; Sulik, M; Brykalska, A; Sobaniec-Lotowska, M; Baltaziak, M

    1990-01-01

    The incidence and histopathologic picture of gelatinous transformation of the bone marrow were analysed in non-selected autopsy material. It was found that gelatinous transformation of the bone marrow occurred in terminal stages of various diseases (malignant neoplasms, chronic inflammation). Histological studies showed that gelatinous transformation of the bone marrow led to atrophy of the hematopoietic and adipose tissues of the bone marrow and accumulation of acid mucopolysaccharides. The patients with gelatinous transformation of the bone marrow exhibit hematologic disorders, most frequently anemia and thrombocytopenia.

  9. Preservation and storage of prepared ballistic gelatine.

    Science.gov (United States)

    Mattijssen, E J A T; Alberink, I; Jacobs, B; van den Boogaard, Y

    2016-02-01

    The use of ballistic gelatine, generally accepted as a human muscle tissue simulant in wound ballistic studies, might be improved by adding a preservative (Methyl 4-hydroxybenzoate) which inhibits microbial growth. This study shows that replacing a part of the gelatine powder by the preservative does not significantly alter the penetration depth of projectiles. Storing prepared blocks of ballistic gelatine over time decreased the penetration depth of projectiles. Storage of prepared gelatine for 4 week already showed a significant effect on the penetration depth of projectiles.

  10. Fractal lattice of gelatin nanoglobules

    Science.gov (United States)

    Novikov, D. V.; Krasovskii, A. N.

    2012-11-01

    The globular structure of polymer coatings on a glass, which were obtained from micellar solutions of gelatin in the isooctane-water-sodium (bis-2-ethylhexyl) sulfosuccinate system, has been studied using electron microscopy. It has been shown that an increase in the average globule size is accompanied by the formation of a fractal lattice of nanoglobules and a periodic physical network of macromolecules in the coating. The stability of such system of the "liquid-in-a-solid" type is limited by the destruction of globules and the formation of a homogeneous network structure of the coating.

  11. Corneal Densitometry for Quantification of Corneal Deposits in Monoclonal Gammopathies.

    Science.gov (United States)

    Enders, Philip; Holtick, Udo; Schaub, Friederike; Tuchscherer, Armin; Hermann, Manuel M; Scheid, Christoph; Cursiefen, Claus; Bachmann, Björn O

    2017-04-01

    To assess the capability of Scheimpflug-based densitometry of the cornea to quantify light chain deposits in patients with active monoclonal gammopathies. This is a case-control study in which data from a leading tertiary university center in myeloma care were analyzed. Ten eyes of 5 patients with monoclonal gammopathy and 26 eyes of 13 healthy controls undergoing clinical evaluation and Scheimpflug-based measurements were included in the study. The main outcome measures were densitometry data of the 4 corneal layers-anterior layer (AL), central layer (CL), posterior layer, and total layer (TL)-in 4 different annuli (central annular zone 0-2 mm, intermediate annular zone 2-6 mm, peripheral annular zone 6-10 mm, and total annular zone 0-12 mm). In 8 eyes of 4 patients with IgG-based gammopathy, corneal light backscatter was highest in the AL and decreased with increasing corneal depth. The peripheral annular zone showed a higher densitometry value compared with the corneal center. Compared with healthy controls, the AL (P < 0.001), the CL (P < 0.001), and the TL (P < 0.001) had significantly higher corneal light backscatter in patients with gammopathy in the total and the peripheral annular zones. In one patient with predominantly IgA-based disease, corneal light backscatter was not elevated. Scheimpflug-based densitometry of the cornea is able to quantify opacification by immunoglobulin G light chain deposits in monoclonal gammopathies. This noninvasive technique can complement presently used in vivo confocal microscopy and corneal photography to objectivize corneal changes. Densitometry might allow monitoring of corneal immunoglobulin deposits in follow-up examinations.

  12. Aloe vera: an in vitro study of effects on corneal wound closure and collagenase activity.

    Science.gov (United States)

    Curto, Elizabeth M; Labelle, Amber; Chandler, Heather L

    2014-11-01

    To evaluate the in vitro effects of an aloe vera solution on (i) the viability and wound healing response of corneal cells and (ii) the ability to alter collagenase and gelatinase activities. Primary cultures of corneal epithelial cells and fibroblasts were prepared from grossly normal enucleated canine globes and treated with an aloe solution (doses ranging from 0.0-2 mg/mL). Cellular viability was evaluated using a colorimetric assay. A corneal wound healing model was used to quantify cellular ingrowth across a defect made on the confluent surface. Anticollagenase and antigelatinase activities were evaluated by incubating a bacterial collagenase/gelatinase with aloe solution (doses ranging from 0.0-500 μg/mL) and comparing outcome measures to a general metalloproteinase inhibitor, 1, 10-phenanthroline, and canine serum (doses ranging from 0.0-100%). None of the concentrations of aloe solution tested significantly affected the viability of corneal epithelial cells or fibroblasts. Concentrations ≤175 μg/mL slightly accelerated corneal epithelial cell wound closure; this change was not significant. Concentrations ≥175 μg/mL significantly (P ≤ 0.001) slowed the rate of corneal fibroblast wound closure, while aloe concentrations Aloe solution did not alter the ability for collagenase to degrade gelatin or collagen Type I but increased the ability for collagenase to degrade Type IV collagen. Although additional experiments are required, lower concentrations of aloe solution may be beneficial in healing of superficial corneal wounds to help decrease fibrosis and speed epithelialization. An increase in collagenase activity with aloe vera warrants further testing before considering in vivo studies. © 2014 American College of Veterinary Ophthalmologists.

  13. Role of nuclear factor-kappaB in interleukin-1-induced collagen degradation by corneal fibroblasts.

    Science.gov (United States)

    Lu, Ying; Fukuda, Ken; Li, Qin; Kumagai, Naoki; Nishida, Teruo

    2006-09-01

    The proinflammatory cytokine interleukin (IL)-1 is implicated in corneal ulceration. The role of nuclear factor (NF)-kappaB in the IL-1-induced degradation of collagen by corneal fibroblasts that underlies corneal ulceration was investigated. Rabbit corneal fibroblasts were cultured in three-dimensional gels of type I collagen with or without IL-1 and sulfasalazine, an inhibitor of NF-kappaB activation. Collagen degradation was assessed from the amount of hydroxyproline generated by acid-heat hydrolysis of culture supernatants. The release of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) into culture supernatants was examined by immunoblot analysis and gelatin zymography, and the cellular abundance of MMP and TIMP mRNAs was determined by reverse transcription and real-time polymerase chain reaction analysis. The phosphorylation and degradation of the NF-kappaB-inhibitory protein IkappaB-alpha were examined by immunoblot analysis. The subcellular localization and DNA binding activity of the p65 subunit of NF-kappaB were evaluated by immunofluorescence analysis and with a colorimetric assay, respectively. The transactivation activity of NF-kappaB was assessed with a reporter gene assay. Sulfasalazine inhibited IL-1-induced collagen degradation by corneal fibroblasts in a concentration-dependent manner. It also inhibited the stimulatory effects of IL-1 on the synthesis or activation of various MMPs in a concentration-dependent manner. IL-1 induced the phosphorylation and degradation of IkappaB-alpha, the nuclear translocation and up-regulation of the DNA binding activity of the p65 subunit of NF-kappaB, and the activation of NF-kappaB in a manner sensitive to sulfasalazine. These results suggest that NF-kappaB contributes to the IL-1-induced degradation of collagen by corneal fibroblasts and is therefore a potential therapeutic target for treatment of corneal ulcers.

  14. Combined effects of interleukin-1β and cyclic stretching on metalloproteinase expression in corneal fibroblasts in vitro.

    Science.gov (United States)

    Feng, Pengfei; Li, Xiaona; Chen, Weiyi; Liu, Chengxing; Rong, Shuo; Wang, Xiaojun; Du, Genlai

    2016-06-10

    Corneal tensile strain increases if the cornea becomes thin or if intraocular pressure increases. However, the effects of mechanical stress on extracellular matrix (ECM) remodelling in the corneal repair process and the corneal anomalies are unknown. In this study, the combined effects of interleukin-1β (IL-1β) on matrix metalloproteinases (MMPs) in corneal fibroblasts under cyclic stretching were investigated in vitro. Cultured rabbit corneal fibroblasts were subjected to 5, 10 or 15 % cyclic equibiaxial stretching at 0.1 Hz for 36 h in the presence of IL-1β. Conditioned medium was harvested for the analysis of MMP2 and MMP9 protein production using the gelatin zymography and western blot techniques. Cyclic equibiaxial stretching changed the cell morphology by increasing the contractility of F-actin fibres. IL-1β alone induced the expression of MMP9 and increased the production of MMP2, and 5 % stretching alone decreased the production of MMP2, which indicates that a low stretching magnitude can reduce ECM degradation. In the presence of IL-1β, 5 and 10 % stretching increased the production of MMP2, whereas 15 % stretching increased the production of MMP9. These results indicate that MMP expression is enhanced by cyclic mechanical stimulation in the presence of IL-1β, which is expected to contribute to corneal ECM degradation, leading to the development of post-refractive surgery keratectasia.

  15. Gelatin

    Science.gov (United States)

    ... joint function in patients with osteoarthritis. Brittle bones (osteoporosis). Strengthening bones and joints. Strengthening fingernails. Improving hair quality. Weight loss. Shortening recovery after exercise and sports-related injury. Other conditions. More evidence ...

  16. [Methods for sealing of corneal perforations].

    Science.gov (United States)

    Samoilă, O; Totu, Lăcrămioara; Călugăru, M

    2012-01-01

    A variety of corneal pathology can lead to corneal ulcers and perforations. A deep corneal ulcer may need surgical treatment to allow good volume restoration and reepithelisation. Corneal perforation must be sealed and when the perforation is large, the task of repairing the defect can be underwhelming. The elegant solution is the corneal transplant, but this is not always readily available, especially in undeveloped countries. We present here two cases with different solutions to seal the perforated cornea: the first one has a large peripheral defect and it is successfully sealed with scleral patch and the second one is central with small perforation and is successfully sealed with multilayered amniotic membrane. Both cases are followed for over 12 months and demonstrate good corneal restoration (both on clinical examination and corneal topography). Sclera and amniotic membrane can be used to seal corneal defects when corneal transplant is not readily available.

  17. Corneal collagen crosslinking: a systematic review.

    Science.gov (United States)

    Sorkin, Nir; Varssano, David

    2014-01-01

    Keratoconus (KCN) is an ectatic disorder with progressive corneal thinning and a clinical picture of corneal protrusion, progressive irregular astigmatism, corneal fibrosis and visual deterioration. Other ectatic corneal disorders include: post-LASIK ectasia (PLE) and pellucid marginal degeneration (PMD). Corneal crosslinking (CXL) is a procedure whereby riboflavin sensitization with ultraviolet A radiation induces stromal crosslinks. This alters corneal biomechanics, causing an increase in corneal stiffness. In recent years, CXL has been an established treatment for the arrest of KCN, PLE and PMD progression. CXL has also been shown to be effective in the treatment of corneal infections, chemical burns, bullous keratopathy and other forms of corneal edema. This is a current review of CXL - its biomechanical principles, the evolution of CXL protocols in the past, present and future, indications for treatment, treatment efficacy and safety.

  18. Corneal Topographic Changes After Eyelid Ptosis Surgery.

    Science.gov (United States)

    Savino, Gustavo; Battendieri, Remo; Riso, Monica; Traina, Salvatore; Poscia, Andrea; DʼAmico, Giovanni; Caporossi, Aldo

    2016-04-01

    To evaluate the corneal topography and the topographic changes after ptosis surgery on patients affected by congenital and acquired blepharoptosis. Twenty eyes of 17 patients affected by acquired and congenital ptosis underwent surgical correction through anterior levator complex tightening. Computerized tomography (Syrius Sistem; CSO) was used to analyze any change in corneal astigmatism (CYL), simulated keratometry, anterior corneal symmetry index front, apical keratometry front, and central corneal thickness. Visual acuity, margin reflex distance, and levator function were also measured. After surgical ptosis repair, corneal topography demonstrated a reduction in average keratometry of 0.15 ± 0.47 diopters (D) and in corneal astigmatism of 0.26 ± 1.12 D. Significant differences were found in apical keratometry front (-1.84 ± 1.76 D) and in best-corrected visual acuity (-0.18 ± 0.06 logMAR) in the postoperative examinations. Central corneal thickness did not show significant differences between preoperative and postoperative examinations. Postoperative topographic maps showed a reduction of symmetry index front (0.10 ± 0.64 D). Eyelid ptosis modifies anterior corneal surface inducing refractive errors and modifying corneal astigmatism in patients, thus affecting the quality of vision. The surgical correction of blepharoptosis induces anterior corneal surface modification, restoring corneal symmetry and regular corneal astigmatism. Postoperative corneal topography showed normal corneal contours.

  19. Patching for corneal abrasion.

    Science.gov (United States)

    Lim, Chris H L; Turner, Angus; Lim, Blanche X

    2016-07-26

    Published audits have demonstrated that corneal abrasions are a common presenting eye complaint. Eye patches are often recommended for treating corneal abrasions despite the lack of evidence for their use. This systematic review was conducted to determine the effects of the eye patch when used to treat corneal abrasions. The objective of this review was to assess the effects of patching for corneal abrasion on healing and pain relief. We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2016), EMBASE (January 1980 to May 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to May 2016), System for Information on Grey Literature in Europe (OpenGrey) (January 1995 to May 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 9 May 2016. We also searched the reference lists of included studies, unpublished 'grey' literature and conference proceedings and contacted pharmaceutical companies for details of unpublished trials. We included randomised and quasi-randomised controlled trials that compared patching the eye with no patching to treat simple corneal abrasions. Two authors independently assessed the risk of bias and extracted data. Investigators were contacted for further information regarding the quality of trials. The primary outcome was healing at 24, 48 and 72 hours while secondary outcomes included measures of pain, quality of life and adverse effects. We graded the certainty of the evidence using GRADE. We included 12 trials which

  20. Microwave Drying Effects On Dichromated Gelatin Holograms

    Science.gov (United States)

    Andrade, Ana A.; Rebordao, Jose M.

    1989-05-01

    Holograms recorded in dichromated gelatin can easily be destroyed when subjected to high temperatures. In this work, a new treatment of holographic dichromated gelatin layers that improves remarkably the hologram life time under adverse thermal conditions, is presented: exposing the developed hologram to microwave radiaton. Similar holograms were subjected to microwave radiation for variable timelengths and then subjected to heating. The resultant angular and spectral bandwidths were measured after different heating time intervals. Some preliminary results will be presented. The role of water in holograms made with dicromated gelatin will be discussed, in this new context.

  1. Collection and culture techniques for gelatinous zooplankton.

    Science.gov (United States)

    Raskoff, Kevin A; Sommer, Freya A; Hamner, William M; Cross, Katrina M

    2003-02-01

    Gelatinous zooplankton are the least understood of all planktonic animal groups. This is partly due to their fragility, which typically precludes the capture of intact specimens with nets or trawls. Specialized tools and techniques have been developed that allow researchers and aquarists to collect intact gelatinous animals at sea and to maintain many of these alive in the laboratory. This paper summarizes the scientific literature on the capture, collection, and culture of gelatinous zooplankton and incorporates many unpublished methods developed at the Monterey Bay Aquarium in the past 15 years.

  2. Chitosan-gelatin biopolymers as carrier substrata for limbal epithelial stem cells.

    Science.gov (United States)

    de la Mata, Ana; Nieto-Miguel, Teresa; López-Paniagua, Marina; Galindo, Sara; Aguilar, María Rosa; García-Fernández, Luis; Gonzalo, Sandra; Vázquez, Blanca; Román, Julio San; Corrales, Rosa María; Calonge, Margarita

    2013-12-01

    The aim of this work was to evaluate semi-synthetic biopolymers based on chitosan (CH) and gelatin (G) as potential in vitro carrier substrata for human limbal epithelial cells (hLECs). To that end, human corneal epithelial cells (HCE) were cultured onto different CH-G membranes. None of the polymers were cytotoxic and cell proliferation was higher when CH was functionalized with G. Expression levels of corneal epithelial markers (K3, K12, E-caherin, desmoplakin, and zonula occludens (ZO)-1) were better maintained in HCE cells grown on CH-G 20:80 membranes than other proportions. Consequently, CH-G 20:80 was chosen for the subsequent expansion of hLECs. Cells derived from limbal explants were successfully expanded on CH-G 20:80 membranes using a culture medium lacking components of non-human animal origin. The expression levels found for corneal (K3 and K12) and limbal epithelial stem cells (K15) specific markers were similar to or higher than those found in limbal cells grown onto the control substratum. Our results demonstrate that CH-G 20:80 membranes are suitable for the expansion and maintenance of stem cells derived from the limbal niche. These results strongly support the use of polymers as alternative substrata for the transplantation of cultivated limbal cells onto the ocular surface.

  3. Corneal collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Jankov II Mirko

    2010-01-01

    Full Text Available Corneal collagen cross-linking (CXL with riboflavin and ultraviolet-A (UVA is a new technique of corneal tissue strengthening by using riboflavin as a photosensitizer and UVA to increase the formation of intra- and interfibrillar covalent bonds by photosensitized oxidation. Keratocyte apoptosis in the anterior segment of the corneal stroma all the way down to a depth of about 300 microns has been described and a demarcation line between the treated and untreated cornea has been clearly shown. It is important to ensure that the cytotoxic threshold for the endothelium has not been exceeded by strictly respecting the minimal corneal thickness. Confocal microscopy studies show that repopulation of keratocytes is already visible 1 month after the treatment, reaching its pre-operative quantity and quality in terms of functional morphology within 6 months after the treatment. The major indication for the use of CXL is to inhibit the progression of corneal ectasias, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photoablation. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. Combination with other treatments, such as intracorneal ring segment implantation, limited topography-guided photoablation and conductive keratoplasty have been used with different levels of success.

  4. Performance of high amylose starch-composited gelatin films influenced by gelatinization and concentration.

    Science.gov (United States)

    Wang, Wenhang; Wang, Kun; Xiao, Jingdong; Liu, Yaowei; Zhao, Yana; Liu, Anjun

    2017-01-01

    In order to study the impact of starch in film performance, high amylose corn starch was composited in gelatin films under different gelatinization conditions and, in high and low concentrations (10 and 50wt.%). It was found that hot water gelatinized starch (Gel-Shw) increased film mechanical strength and was dependent upon the starch concentration. The addition of an alkali component to the starch significantly enhanced the swelling of the starch granules and expedited the gelatinization process. Incorporation of starch, especially the alkalized starch (Sha), into the gelatin films decreased film solubility which improved its water resistance and water vapor permeability (WVP). Multiple techniques (DSC, TGA, FT-IR, and XRD) were used to characterize the process and results, including the crosslinking of the dissolved starch molecules and the particles formed from gelatinized starch during retrogradation process, which played an important role in improving the thermal stability of the composited gelatin films. Overall, the starch-gelatin composition provides a potential approach to improve gelatin film performance and benefit its applications in the food industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Role of protein kinase C signaling in collagen degradation by rabbit corneal fibroblasts cultured in three-dimensional collagen gels.

    Science.gov (United States)

    Nagano, Takashi; Hao, Ji-Long; Nakamura, Masatsugu; Nishida, Teruo

    2002-08-01

    To understand the mechanism of corneal ulceration by characterizing the intracellular signaling pathways that regulate collagen degradation by corneal fibroblasts cultured in three-dimensional type I collagen gels. Specifically, the potential roles of protein kinase C (PKC) and protein kinase A (PKA) in collagen degradation were investigated. Rabbit corneal fibroblasts were cultured in three-dimensional type I collagen gels for 24 hours in the presence of plasminogen and in the absence or presence of activators or inhibitors of PKC or PKA. Degradation of collagen fibrils was then evaluated by measurement of released hydroxyproline, and the production of matrix metalloproteinases (MMPs) was assessed by gelatin zymography and immunoblot analysis. The PKC activator phorbol 12-myristate 13-acetate (PMA) increased the extent of collagen degradation by corneal fibroblasts in a dose-dependent manner, with the maximal effect apparent at a concentration of 0.1 microM. The inactive analog 4alpha-PMA had no effect on collagen degradation. The PKC inhibitor H-7 reduced the extent of collagen degradation by corneal fibroblasts in the absence or presence of PMA. Phorbol 12-myristate 13-acetate also increased the production of proMMP-1, -3, and -9 by corneal fibroblasts, whereas H-7 inhibited this effect. Neither the PKA activators 8-bromo-cAMP, isobutylmethylxanthine, and forskolin nor the PKA inhibitor HA1004 affected collagen degradation by corneal fibroblasts. These results demonstrate that PKC plays an important role in collagen degradation by corneal fibroblasts in three-dimensional type I collagen gels, whereas PKA does not appear to participate in this process.

  6. Suppression by an RAR-γ Agonist of Collagen Degradation Mediated by Corneal Fibroblasts.

    Science.gov (United States)

    Kimura, Kazuhiro; Zhou, Hongyan; Orita, Tomoko; Kobayashi, Masaaki; Nishida, Teruo; Sonoda, Koh-Hei

    2017-04-01

    To examine the role of retinoic acid receptor (RAR) isoforms in interleukin-1β (IL-1β)-induced collagen degradation by corneal fibroblasts. Primary rabbit corneal fibroblasts embedded in a three-dimensional collagen gel were incubated with or without all-trans retinoic acid (ATRA), the RAR-α agonist Am580, the RAR-β agonist AC55649, or the RAR-γ agonist R667. Collagen degradation was determined by measurement of hydroxyproline produced in acid hydrolysates of culture supernatants. Matrix metalloproteinase (MMP) expression was evaluated by immunoblot analysis and gelatin zymography. The phosphorylation of mitogen-activated protein kinases (MAPKs) and the endogenous nuclear factor (NF)-κB inhibitor IκB-α was examined by immunoblot analysis. Cell proliferation was measured with a bromodeoxyuridine incorporation assay, and cell viability was determined by measurement of the release of lactate dehydrogenase. Interleukin-1β-induced collagen degradation by corneal fibroblasts was inhibited by ATRA, Am580, and R667 in a concentration-dependent manner but was unaffected by AC55649, with the inhibitory effects of ATRA and R667 being markedly greater than that of Am580. The IL-1β-induced production of MMP-1, MMP-2, MMP-3, and MMP-9 by corneal fibroblasts was also inhibited by R667 in a concentration-dependent manner. R667 inhibited the IL-1β-induced phosphorylation of IκB-α but not that of MAPKs. R667 had no effect on the proliferation or viability of corneal fibroblasts. The RAR-γ agonist R667 suppressed MMP production and thereby inhibited collagen degradation by corneal fibroblasts exposed to the proinflammatory cytokine IL-1β. These effects of R667 may be mediated by the NF-κB signaling pathway.

  7. Dexamethasone inhibition of IL-1-induced collagen degradation by corneal fibroblasts in three-dimensional culture.

    Science.gov (United States)

    Lu, Ying; Fukuda, Ken; Liu, Yang; Kumagai, Naoki; Nishida, Teruo

    2004-09-01

    Corticosteroids regulate the functions of inflammatory cells. The purpose of the present study was to investigate the effect of dexamethasone on collagen degradation by corneal fibroblasts, an underlying cause of corneal ulceration. Rabbit corneal fibroblasts were cultured in three-dimensional gels of type I collagen and in the absence or presence of IL-1beta or dexamethasone. The extent of collagen degradation was determined by measurement of the amount of hydroxyproline generated by acid-heat hydrolysis of culture supernatants. The expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) was evaluated by immunoblot analysis, gelatin zymography, and reverse transcription and real-time polymerase chain reaction. The phosphorylation of mitogen-activated protein kinases (MAPKs) in corneal fibroblasts was assessed by immunoblot analysis. Dexamethasone inhibited IL-1beta-induced collagen degradation by corneal fibroblasts in a dose-dependent manner. Both the synthesis and activation of MMPs and the expression of TIMPs were inhibited by dexamethasone, as was the activity of plasmin in culture supernatants. Dexamethasone also inhibited the IL-1beta-induced phosphorylation of the MAPKs extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), but not that of p38. Dexamethasone exerted multiple effects on the MMP-TIMP system in corneal fibroblasts and thereby inhibited IL-1beta-induced collagen degradation by these cells. Inhibition of the IL-1beta-induced activation of ERK and JNK may contribute to these effects of dexamethasone. Copyright Association for Research in Vision and Ophthalmology

  8. Corneal stromal dystrophies: a clinical pathologic study

    Directory of Open Access Journals (Sweden)

    Elvira Barbosa Abreu

    2012-12-01

    Full Text Available INTRODUCTION: Corneal dystrophy is defined as bilateral and symmetric primary corneal disease, without previous associated ocular inflammation. Corneal dystrophies are classified according to the involved corneal layer in superficial, stromal, and posterior dystrophy. Incidence of each dystrophy varies according to the geographic region studied. PURPOSE: To evaluate the prevalence of stromal corneal dystrophies among corneal buttons specimens obtained by penetrating keratoplasty (PK in an ocular pathology laboratory and to correlate the diagnosis with patient age and gender. METHODS: Corneal button cases of penetrating keratoplasty from January-1996 to May-2009 were retrieved from the archives of The Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, Montreal, Canada. The cases with histopathological diagnosis of stromal corneal dystrophies were stained with special stains (Peroxid acid Schiff, Masson trichrome, Congo red analyzed under polarized light, and alcian blue for classification and correlated with epidemiological information (age at time of PK and gender from patients' file. RESULTS: 1,300 corneal buttons cases with clinical diagnose of corneal dystrophy were retrieved. Stromal corneal dystrophy was found in 40 (3.1% cases. Lattice corneal dystrophy was the most prevalent with 26 cases (65%. Nineteen were female (73.07% and the PK was performed at average age of 59.3 years old. Combined corneal dystrophy was found in 8 (20% cases, 5 (62.5% of them were female and the average age of the penetrating keratoplasty was 54.8 years old. Granular corneal dystrophy was represented by 5 (12.5% cases, and 2 (40% of them were female. Penetrating keratoplasty was performed at average age of 39.5 years old in granular corneal dystrophy cases. Macular corneal dystrophy was present in only 1 (2.5% case, in a 36 years old female. CONCLUSION: Systematic histopathological approach and evaluation, including special stains in all stromal

  9. Evaluation of Factors Limiting Corneal Donation.

    Science.gov (United States)

    Röck, Daniel; Wude, Johanna; Yoeruek, Efdal; Bartz-Schmidt, Karl Ulrich; Röck, Tobias

    2016-11-15

    BACKGROUND This study aimed to investigate factors limiting corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS We retrospectively studied all hospital deaths from January 2012 to December 2015, considering each deceased patient as a potential corneal donor. During this period an ophthalmic resident managed corneal donor procurement on a full-time basis. Various factors limiting corneal donation were examined. RESULTS Among the 3412 deaths, 2937 (86.1%) displayed nonfulfillment of corneal donation. Consent for corneal donation was obtained in 475 cases (13.9%). The mean annual corneal donation rate was 13.9 donors per 100 deaths (range: 11.2-17.8). The leading causes of nonfulfillment of corneal donations were refusal to donate (49.8%, 1698 cases) and medical contraindications (23.6%, 805 cases). After next-of-kin interview of 2173 potential donors (109 potential donors were excluded because of logistical problems), willingness to participate in corneal donation was present in 475 cases (21.9%), whereas in 1698 cases (78.1%) corneal donation was refused. CONCLUSIONS Our study showed refusal to donate is the most important factor limiting corneal donation. It seems that increasing the knowledge of people about corneal donation through public education and media are necessary to address the corneal shortage.

  10. Aligned Fibrous Scaffold Induced Aligned Growth of Corneal Stroma Cells in vitro Culture

    Institute of Scientific and Technical Information of China (English)

    GAO Yan; YAN Jing; CUI Xue-jun; WANG Hong-yan; WANG Qing

    2012-01-01

    To investigate the contribution of fibre arrangement to guiding the aligned growth of corneal stroma cells,aligned and randomly oriented fibrous scaffolds of gelatin and poly-L-lactic acid(PLLA) were fabricated by electrospinning.A comparative study of two different systems with corneal stroma cells on randomly organized and aligned fibres were conducted.The efficiency of the scaffolds for inducing the aligned growth of cells was assessed by morphological observation and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT) assay.Results show that the cells cultured on both randomly oriented and aligned scaffolds maintained normal morphology and well spreading as well as long term proliferation.Importantly,corneal stroma cells grew high orderly on the aligned scaffold,while the cells grew disordered on the randomly oriented scaffold.Moreover,the cells exhibited higher viability in aligned scaffold than that in randomly oriented scaffold.These results indcate that electrospinng to prepare aligned fibrous scaffolds has provided an effective approach to the aligned growth of corneal stroma cells in vitro.Our findings that fiber arrangement plays a crucial role in guiding the aligned growth of cells may be helpful to the development of better biomaterials for tissue engineered cornea.

  11. Gelatin microcapsules for enhanced microwave tumor hyperthermia

    Science.gov (United States)

    Du, Qijun; Fu, Changhui; Tie, Jian; Liu, Tianlong; Li, Linlin; Ren, Xiangling; Huang, Zhongbing; Liu, Huiyu; Tang, Fangqiong; Li, Li; Meng, Xianwei

    2015-02-01

    Local and rapid heating by microwave (MW) irradiation is important in the clinical treatment of tumors using hyperthermia. We report here a new thermo-seed technique for the highly efficient MW irradiation ablation of tumors in vivo based on gelatin microcapsules. We achieved 100% tumor elimination in a mouse model at an ultralow power of 1.8 W without any side-effects. The results of MTT assays, a hemolysis test and the histological staining of organs indicated that the gelatin microcapsules showed excellent compatibility with the physiological environment. A possible mechanism is proposed for MW hyperthermia using gelatin microcapsules. We also used gelatin microcapsules capped with CdTe quantum dots for in vivo optical imaging. Our study suggests that these microcapsules may have potential applications in imaging-guided cancer treatment.Local and rapid heating by microwave (MW) irradiation is important in the clinical treatment of tumors using hyperthermia. We report here a new thermo-seed technique for the highly efficient MW irradiation ablation of tumors in vivo based on gelatin microcapsules. We achieved 100% tumor elimination in a mouse model at an ultralow power of 1.8 W without any side-effects. The results of MTT assays, a hemolysis test and the histological staining of organs indicated that the gelatin microcapsules showed excellent compatibility with the physiological environment. A possible mechanism is proposed for MW hyperthermia using gelatin microcapsules. We also used gelatin microcapsules capped with CdTe quantum dots for in vivo optical imaging. Our study suggests that these microcapsules may have potential applications in imaging-guided cancer treatment. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07104b

  12. Corneal Biomechanical Findings in Contact Lens Induced Corneal Warpage

    Science.gov (United States)

    Letafatnejad, Mojgan; Beheshtnejad, Amir Hooshang; Ghaffary, Seyed Reza; Hassanpoor, Narges; Yaseri, Mehdi

    2016-01-01

    Purpose. To evaluate the difference in biomechanical properties between contact lens induced corneal warpage and normal and keratoconic eyes. Method. Prospective observational case control study, where 94 eyes of 47 warpage suspicious and 46 eyes of 23 keratoconic patients were included. Warpage suspected cases were followed until a definite diagnosis was made (warpage, normal, or keratoconus). Results. 44 eyes of 22 patients had contact lens related corneal warpage. 46 eyes of 23 people were diagnosed as nonwarpage normal eyes. 46 eyes of 23 known keratoconus patients were included for comparison. The mean age of the participants was 23.8 ± 3.8 years, and 66.2% of the subjects were female. The demographic and refractive data were not different between warpage and normal groups but were different in the keratoconus group. The biomechanical properties (corneal hysteresis or CH and corneal resistance factor or CRF) were different with the highest value in the warpage group followed by normal and keratoconus groups. CRF was 10.08 ± 1.75, 9.23 ± 1.22, and 7.38 ± 2.14 and CH was 10.21 ± 1.57, 9.59 ± 1.21, and 8.69 ± 2.34 in the warpage, normal, and keratoconus groups, respectively. Conclusion. Corneal biomechanics may be different in people who develop contact lens induced warpage. PMID:27688908

  13. Enzyme-Gelatin Electrochemical Biosensors: Scaling Down

    Directory of Open Access Journals (Sweden)

    Hendrik A. Heering

    2012-03-01

    Full Text Available In this article we investigate the possibility of scaling down enzyme-gelatin modified electrodes by spin coating the enzyme-gelatin layer. Special attention is given to the electrochemical behavior of the selected enzymes inside the gelatin matrix. A glassy carbon electrode was used as a substrate to immobilize, in the first instance, horse heart cytochrome c (HHC in a gelatin matrix. Both a drop dried and a spin coated layer was prepared. On scaling down, a transition from diffusion controlled reactions towards adsorption controlled reactions is observed. Compared to a drop dried electrode, a spin coated electrode showed a more stable electrochemical behavior. Next to HHC, we also incorporated catalase in a spin coated gelatin matrix immobilized on a glassy carbon electrode. By spincoating, highly uniform sub micrometer layers of biocompatible matrices can be constructed. A full electrochemical study and characterization of the modified surfaces has been carried out. It was clear that in the case of catalase, gluteraldehyde addition was needed to prevent leaking of the catalase from the gelatin matrix.

  14. Reconstruction of Rabbit Corneal Layer Composed of Corneal Fibroblasts and Corneal Epithelium on the Lyophilized Amniotic Membrane

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Many researchers have employed the cryopreserved amniotic membrane(CAM) and corneal epithelial cells in the treatment of a severely damaged burned cornea, with corneal epithelial cells cultured on an amniotic membrane (AM). The lyophilized amniotic membrane (LAM) has a higher graft take and a longer shelf life; it is easier to store and safer because of gamma irradiation. Two Teflon rings(Ahn's supporter) were made for culturing the cells on the LAM, and were then used to support the LAM. To reconstruct a corneal layer composed of corneal fibroblasts and epithelium, the corneal fibroblasts were first cultivated on the stromal side of LAM for five days, followed by epithelial cells culture on the epithelial side, by using the air-liquid interface culture. The reconstructed corneal layer composed of corneal fibroblasts and corneal epithelial cells has a much healthier basal layer of corneal epithelium than the reconstructed corneal epithelium, which was got by using only corneal epithelial cells, and resembles the epithelium of normal corneas, without the horny layer. Thus, the reconstruction of the corneal layer by using a LAM is considered to be a good in vitro model, not only for its application in toxicological test kits, but also for transplantation in patients with a severely damaged cornea.

  15. Halal authenticity of gelatin using species-specific PCR.

    Science.gov (United States)

    Shabani, Hessam; Mehdizadeh, Mehrangiz; Mousavi, Seyed Mohammad; Dezfouli, Ehsan Ansari; Solgi, Tara; Khodaverdi, Mahdi; Rabiei, Maryam; Rastegar, Hossein; Alebouyeh, Mahmoud

    2015-10-01

    Consumption of food products derived from porcine sources is strictly prohibited in Islam. Gelatin, mostly derived from bovine and porcine sources, has many applications in the food and pharmaceutical industries. To ensure that food products comply with halal regulations, development of valid and reliable analytical methods is very much required. In this study, a species-specific polymerase chain reaction (PCR) assay using conserved regions of mitochondrial DNA (cytochrome b gene) was performed to evaluate the halal authenticity of gelatin. After isolation of DNA from gelatin powders with known origin, conventional PCR using species-specific primers was carried out on the extracted DNA. The amplified expected PCR products of 212 and 271 bp were observed for porcine and bovine gelatin, respectively. The sensitivity of the method was tested on binary gelatin mixtures containing 0.1%, 1%, 10%, and 100% (w/w) of porcine gelatin within bovine gelatin and vice versa. Although most of the DNA is degraded due to the severe processing steps of gelatin production, the minimum level of 0.1% w/w of both porcine and bovine gelatin was detected. Moreover, eight food products labeled as containing bovine gelatin and eight capsule shells were subjected to PCR examination. The results showed that all samples contained bovine gelatin, and the absence of porcine gelatin was verified. This method of species authenticity is very useful to verify whether gelatin and gelatin-containing food products are derived from halal ingredients.

  16. Corneal biomechanics: a review.

    Science.gov (United States)

    Piñero, David P; Alcón, Natividad

    2015-03-01

    Biomechanics is often defined as 'mechanics applied to biology'. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that are currently commercially available (Ocular Response Analyzer and CorVis ST). The clinical applicability of the parameters provided by these devices are discussed, especially in the fields of glaucoma, detection of ectatic disorders and orthokeratology. Likewise, other methods are also reviewed, such as Brillouin microscopy or dynamic optical coherence tomography and others with potential application to clinical practice but not validated for in vivo measurements, such as ultrasonic elastography. Advantages and disadvantages of all these techniques are described. Finally, the concept of biomechanical modelling is revised as well as the requirements for developing biomechanical models, with special emphasis on finite element modelling.

  17. Corneal Decompensation after Selective Laser Trabeculoplasty

    Directory of Open Access Journals (Sweden)

    Ahmet Ozkok

    2014-01-01

    Full Text Available A 64-year-old Caucasian man referred for decreased vision after selective laser trabeculoplasty (SLT. Slit lamp examination revealed diffuse corneal edema. Despite intensive topical treatment including steroids, corneal edema did not resolve; on the contrary, it advanced to bullous keratopathy. Corneal edema after SLT is an exceptionally rare complication and in all of the previous reports edema resolved with medical treatment. To the best of our knowledge, this is the first report presenting persistent corneal edema after SLT.

  18. Chip electrophoresis of gelatin-based nanoparticles.

    Science.gov (United States)

    Weiss, Victor U; Lehner, Angela; Grombe, Ringo; Marchetti-Deschmann, Martina; Allmaier, Günter

    2013-08-01

    Recently, biodegradable nanoparticles received increasing attention for pharmaceutical applications as well as applications in the food industry. With the current investigation we demonstrate chip electrophoresis of fluorescently (FL) labeled gelatin nanoparticles (gelatin NPs) on a commercially available instrument. FL labeling included a step for the removal of low molecular mass material (especially excess dye molecules). Nevertheless, for the investigated gelatin NP preparation two analyte peaks, one very homogeneous with an electrophoretic net mobility of μ = -24.6 ± 0.3 × 10(-9) m(2) /Vs at the peak apex (n = 17) and another more heterogeneous peak with μ between approximately -27.2 ± 0.2 × 10(-9) m(2) /Vs and -36.6 ± 0.2 × 10(-9) m(2) /Vs at the peak beginning and end point (n = 11, respectively) were recorded. Filtration allowed enrichment of particles in the size range of approximately 35 nm (pore size employed for concentration of gelatin NPs) to 200 nm (pore size employed during FL labeling). This corresponded to the very homogeneous peak linking it to gelatin NPs, whereas the more heterogeneous peak probably corresponds to gelatin not cross-linked to such a high degree (NP building blocks). Several further gelatin NP preparations were analyzed according to the same protocol yielding peaks with electrophoretic net mobilities between -23.3 ± 0.3 × 10(-9) m(2) /Vs and -28.9 ± 0.2 × 10(-9) m(2) /Vs at peak apexes (n = 15 and 6). Chip electrophoresis allows analyte separation in less than two minutes (including electrophoretic sample injection). Together with the high sensitivity of the FL detection - the LOD as derived for the first main peak of the applied dye from the threefold standard deviation of the background noise values 80 pM for determined separation conditions - this leads to a very promising high throughput separation technique especially for the analysis of bionanoparticles. For gelatin NP preparations, chip electrophoresis

  19. Progress of research on corneal collagen cross-linking for corneal melting

    Directory of Open Access Journals (Sweden)

    Ke-Ren Xiao

    2016-06-01

    Full Text Available Corneal collagen cross-linking(CXLcould increase the mechanical strength, biological stability and halt ectasia progression due to covalent bond formed by photochemical reaction between ultraviolet-A and emulsion of riboflavin between collagen fibers in corneal stroma. Corneal melting is an autoimmune related noninfectious corneal ulcer. The mechanism of corneal melting, major treatment, the basic fundamental of ultraviolet-A riboflavin induced CXL and the clinical researches status and experiment in CXL were summarized in the study.

  20. Ocular dimensions, corneal thickness, and corneal curvature in quarter horses with hereditary equine regional dermal asthenia.

    Science.gov (United States)

    Badial, Peres R; Cisneros-Àlvarez, Luis Emiliano; Brandão, Cláudia Valéria S; Ranzani, José Joaquim T; Tomaz, Mayana A R V; Machado, Vania M; Borges, Alexandre S

    2015-09-01

    The aim of this study was to compare ocular dimensions, corneal curvature, and corneal thickness between horses affected with hereditary equine regional dermal asthenia (HERDA) and unaffected horses. Five HERDA-affected quarter horses and five healthy control quarter horses were used. Schirmer's tear test, tonometry, and corneal diameter measurements were performed in both eyes of all horses prior to ophthalmologic examinations. Ultrasonic pachymetry was performed to measure the central, temporal, nasal, dorsal, and ventral corneal thicknesses in all horses. B-mode ultrasound scanning was performed on both eyes of each horse to determine the dimensions of the ocular structures and to calculate the corneal curvature. Each corneal region examined in this study was thinner in the affected group compared with the healthy control group. However, significant differences in corneal thickness were only observed for the central and dorsal regions. HERDA-affected horses exhibited significant increases in corneal curvature and corneal diameter compared with unaffected animals. The ophthalmologic examinations revealed mild corneal opacity in one eye of one affected horse and in both eyes of three affected horses. No significant between-group differences were observed for Schirmer's tear test, intraocular pressure, or ocular dimensions. Hereditary equine regional dermal asthenia-affected horses exhibit decreased corneal thickness in several regions of the cornea, increased corneal curvature, increased corneal diameter, and mild corneal opacity. Additional research is required to determine whether the increased corneal curvature significantly impacts the visual accuracy of horses with HERDA. © 2014 American College of Veterinary Ophthalmologists.

  1. Acute corneal hydrops in keratoconus

    Directory of Open Access Journals (Sweden)

    Prafulla K Maharana

    2013-01-01

    Full Text Available Acute corneal hydrops is a condition characterized by stromal edema due to leakage of aqueous through a tear in descemet membrane. The patient presents with sudden onset decrease in vision, photophobia, and pain. Corneal thinning and ectasias combined with trivial trauma to the eye mostly by eye rubbing is considered as the underlying cause. With conservative approach self-resolution takes around 2 to 3 months. Surgical intervention is required in cases of non-resolution of corneal edema to avoid complications and for early visual rehabilitation. Intracameral injection of air or gas such as perflouropropane is the most common surgical procedure done. Recent investigative modality such as anterior segment optical coherence tomography is an extremely useful tool for diagnosis, surgical planning, and postoperative follow up. Resolution of hydrops may improve the contact lens tolerance and visual acuity but most cases require keratoplasty for visual rehabilitation.

  2. Posterior Corneal Surface Stability after Femtosecond Laser-Assisted Keratomileusis

    Directory of Open Access Journals (Sweden)

    Carlo Cagini

    2015-01-01

    Full Text Available The purpose of this study was to evaluate posterior corneal surface variation after femtosecond laser-assisted keratomileusis in patients with myopia and myopic astigmatism. Patients were evaluated by corneal tomography preoperatively and at 1, 6, and 12 months. We analyzed changes in the posterior corneal curvature, posterior corneal elevation, and anterior chamber depth. Moreover, we explored correlation between corneal ablation depth, residual corneal thickness, percentage of ablated corneal tissue, and preoperative corneal thickness. During follow-up, the posterior corneal surface did not have a significant forward corneal shift: no significant linear relationships emerged between the anterior displacement of the posterior corneal surface and corneal ablation depth, residual corneal thickness, or percentage of ablated corneal tissue.

  3. Correlations between corneal and total wavefront aberrations

    Science.gov (United States)

    Mrochen, Michael; Jankov, Mirko; Bueeler, Michael; Seiler, Theo

    2002-06-01

    Purpose: Corneal topography data expressed as corneal aberrations are frequently used to report corneal laser surgery results. However, the optical image quality at the retina depends on all optical elements of the eye such as the human lens. Thus, the aim of this study was to investigate the correlations between the corneal and total wavefront aberrations and to discuss the importance of corneal aberrations for representing corneal laser surgery results. Methods: Thirty three eyes of 22 myopic subjects were measured with a corneal topography system and a Tschernig-type wavefront analyzer after the pupils were dilated to at least 6 mm in diameter. All measurements were centered with respect to the line of sight. Corneal and total wavefront aberrations were calculated up to the 6th Zernike order in the same reference plane. Results: Statistically significant correlations (p corneal and total wavefront aberrations were found for the astigmatism (C3,C5) and all 3rd Zernike order coefficients such as coma (C7,C8). No statistically significant correlations were found for all 4th to 6th order Zernike coefficients except for the 5th order horizontal coma C18 (p equals 0.003). On average, all Zernike coefficients for the corneal aberrations were found to be larger compared to Zernike coefficients for the total wavefront aberrations. Conclusions: Corneal aberrations are only of limited use for representing the optical quality of the human eye after corneal laser surgery. This is due to the lack of correlation between corneal and total wavefront aberrations in most of the higher order aberrations. Besides this, the data present in this study yield towards an aberration balancing between corneal aberrations and the optical elements within the eye that reduces the aberration from the cornea by a certain degree. Consequently, ideal customized ablations have to take both, corneal and total wavefront aberrations, into consideration.

  4. Progress in corneal wound healing.

    Science.gov (United States)

    Ljubimov, Alexander V; Saghizadeh, Mehrnoosh

    2015-11-01

    Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β (TGF-β) system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal

  5. Progress in corneal wound healing

    Science.gov (United States)

    Ljubimov, Alexander V.; Saghizadeh, Mehrnoosh

    2015-01-01

    Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal epithelium, and

  6. [Corneal manifestations in systemic diseases].

    Science.gov (United States)

    Zarranz Ventura, J; De Nova, E; Moreno-Montañés, J

    2008-01-01

    Systemic diseases affecting the cornea have a wide range of manifestations. The detailed study of all pathologies that cause corneal alteration is unapproachable, so we have centered our interest in the most prevalent or characteristic of them. In this paper we have divided these pathologies in sections to facilitate their study. Pulmonar and conective tissue (like colagen, rheumatologic and idiopathic inflamatory diseases), dermatologic, cardiovascular, hematologic, digestive and hepatopancreatic diseases with corneal alteration are described. Endocrine and metabolic diseases, malnutrition and carential states are also studied, as well as some otorhinolaryngologic and genetic diseases that affect the cornea. Finally, a brief report of ocular toxicity induced by drugs is referred.

  7. Corneal Regeneration After Photorefractive Keratectomy: A Review.

    Science.gov (United States)

    Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane; Hanneken, Ludger

    2015-01-01

    Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  8. Controlled release gelatin hydrogels and lyophilisates with potential application as ocular inserts

    Energy Technology Data Exchange (ETDEWEB)

    Natu, Madalina V [Department of Chemical Engineering, University of Coimbra, Polo II, Pinhal de Marrocos, 3030-290 Coimbra (Portugal); Sardinha, Jose P [Department of Chemical Engineering, University of Coimbra, Polo II, Pinhal de Marrocos, 3030-290 Coimbra (Portugal); Correia, IlIdio J [Centro de Investigacao em Ciencias da Saude, Faculdade de Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Gil, M H [Department of Chemical Engineering, University of Coimbra, Polo II, Pinhal de Marrocos, 3030-290 Coimbra (Portugal)

    2007-12-15

    Hydrogels and lyophilisates were obtained by chemical crosslinking of gelatin using N-hydroxysuccinimide and N, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride. The systems were characterized with respect to the degree of crosslinking, morphology, water uptake, in vitro drug release and biocompatibility studies. Pilocarpine hydrochloride, a drug for the treatment of glaucoma, was loaded by soaking in an aqueous solution containing the drug. In vitro, the released drug percentage varied between 29.2% and 99.2% in 8 h of study. The release data were fitted to the Korsmeyer-Peppas equation to calculate the release exponent, which indicated anomalous transport for the release of pilocarpine. The corneal endothelial cell culture tests indicated that the prepared biomaterials are not cytotoxic.

  9. Understanding starch gelatinization: The phase diagram approach.

    Science.gov (United States)

    Carlstedt, Jonas; Wojtasz, Joanna; Fyhr, Peter; Kocherbitov, Vitaly

    2015-09-20

    By constructing a detailed phase diagram for the potato starch-water system based on data from optical microscopy, synchrotron X-ray scattering and differential scanning calorimetry, we show that gelatinization can be interpreted in analogy with a eutectic transition. The phase rule explains why the temperature of the gelatinization transition (G) is independent on water content. Furthermore, the melting (M1) endotherm observed in DSC represents a liquidus line; the temperature for this event increases with increasing starch concentration. Both the lamellar spacing and the inter-helix distance were observed to decrease with increasing starch content for starch concentrations between approximately 65 wt% and 75 wt%, while the inter-helix distance continued decreasing upon further dehydration. Understanding starch gelatinization has been a longstanding challenge. The novel approach presented here shows interpretation of this phenomenon from a phase equilibria perspective. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Corneal stroma microfibrils

    KAUST Repository

    Hanlon, Samuel D.

    2015-03-01

    Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (~10nm diameter). Immunogold evidence clearly

  11. Corneale crosslinking voor progressieve keratoconus

    NARCIS (Netherlands)

    Wisse, Robert P L; Soeters, Nienke; Godefrooij, Daniel A.; De Koning-Tahzib, Nayyirih G.

    2016-01-01

    Keratoconus is a corneal disease with onset typically occurring during puberty or early adulthood. The cornea progressively thins and acquires a cone-like shape which negatively affects visual acuity. In the early stages, visual acuity can be corrected with glasses or contact lenses. In more

  12. Corneale crosslinking voor progressieve keratoconus

    NARCIS (Netherlands)

    Wisse, Robert P L; Soeters, Nienke; Godefrooij, Daniel A.; De Koning-Tahzib, Nayyirih G.

    2016-01-01

    Keratoconus is a corneal disease with onset typically occurring during puberty or early adulthood. The cornea progressively thins and acquires a cone-like shape which negatively affects visual acuity. In the early stages, visual acuity can be corrected with glasses or contact lenses. In more advance

  13. Terahertz sensing of corneal hydration.

    Science.gov (United States)

    Singh, Rahul S; Tewari, Priyamvada; Bourges, Jean Louis; Hubschman, Jean Pierre; Bennett, David B; Taylor, Zachary D; Lee, H; Brown, Elliott R; Grundfest, Warren S; Culjat, Martin O

    2010-01-01

    An indicator of ocular health is the hydrodyanmics of the cornea. Many corneal disorders deteriorate sight as they upset the normal hydrodynamics of the cornea. The mechanisms include the loss of endothelial pump function of corneal dystophies, swelling and immune response of corneal graft rejection, and inflammation and edema, which accompany trauma, burn, and irritation events. Due to high sensitivity to changes of water content in materials, a reflective terahertz (300 GHz and 3 THz) imaging system could be an ideal tool to measure the hydration level of the cornea. This paper presents the application of THz technology to visualize the hydration content across ex vivo porcine corneas. The corneas, with a thickness variation from 470 - 940 µm, were successfully imaged using a reflective pulsed THz imaging system, with a maximum SNR of 50 dB. To our knowledge, no prior studies have reported on the use of THz in measuring hydration in corneal tissues or other ocular tissues. These preliminary findings indicate that THz can be used to accurately sense hydration levels in the cornea using a pulsed, reflective THz imaging system.

  14. Gelatin use impairs platelet adhesion during cardiac surgery

    NARCIS (Netherlands)

    Tabuchi, N; deHaan, J; Huet, RCGG; Boonstra, PW; vanOeveren, W

    1995-01-01

    Artificial colloids based on gelatin are used as plasma expander to replace donor blood products. In laboratory experiments, gelatin reduced both the velocity and extend of platelet agglutination by ristocetin, and only the agglutination velocity by polybrene (p These negative effects of gelatin on

  15. Physicochemical and functional properties of gelatin extracted from Yak skin.

    Science.gov (United States)

    Xu, Mengqi; Wei, Lixin; Xiao, Yuancan; Bi, Hongtao; Yang, Hongxia; Du, Yuzhi

    2017-02-01

    Different molecular weight distribution (MWD) gelatin was extracted from Yak skin after enzymatic pretreatments and their physicochemical and functional properties (SDS-PAGE, UV-vis absorption spectra, DSC, FT-IR, Amino acid analysis, AFM, emulsibility and foamability) were analyzed. The gelatin was extracted by pepsin and got different MWD of Yak skin gelatin by controlling the enzymolysis time. The SDS-PAGE showed the MWD of the Yak skin gelatin. The UV-vis absorption turned out that the broad MWD of Yak skin gelatin had a higher maximum absorption peaks. The FT-IR and AFM indicated that the gelatin structures and microstructures changed with the change of the MWD. The broad MWD of the Yak skin gelatin had a higher denaturation temperature (TD), and it was higher than most of the other mammals and marine biological gelatin. The broad MWD gelatin also had higher imino acids (proline and hydroxyproline) contents and lower foamability and emulsibility compared to the narrow MWD gelatin. These findings, obtained for the first time for Yak skin gelatin, showed that it has great potential for application as an alternative to commercial gelatin due to its good thermotolerance, particularly in the applications of the biological materials, stabilizer of thermo-tolerant and so on.

  16. Management of corneal bee sting

    Directory of Open Access Journals (Sweden)

    Razmjoo H

    2011-12-01

    Full Text Available Hassan Razmjoo1,2, Mohammad-Ali Abtahi1,2,4, Peyman Roomizadeh1,3, Zahra Mohammadi1,2, Seyed-Hossein Abtahi1,3,41Medical School, Isfahan University of Medical Sciences (IUMS; 2Ophthalmology Ward, Feiz Hospital, IUMS; 3Isfahan Medical Students Research Center (IMSRC, IUMS; 4Isfahan Ophthalmology Research Center (IORC, Feiz Hospital, IUMS, Isfahan, IranAbstract: Corneal bee sting is an uncommon environmental eye injury that can result in various ocular complications with an etiology of penetrating, immunologic, and toxic effects of the stinger and its injected venom. In this study we present our experience in the management of a middle-aged male with a right-sided deep corneal bee sting. On arrival, the patient was complaining of severe pain, blurry vision with acuity of 160/200, and tearing, which he had experienced soon after the injury. Firstly, we administered conventional drugs for eye injuries, including topical antibiotic, corticosteroid, and cycloplegic agents. After 2 days, corneal stromal infiltration and edema developed around the site of the sting, and visual acuity decreased to 100/200. These conditions led us to remove the stinger surgically. Within 25 days of follow-up, the corneal infiltration decreased gradually, and visual acuity improved to 180/200. We suggest a two-stage management approach for cases of corneal sting. For the first stage, if the stinger is readily accessible or primary dramatic reactions, including infiltration, especially on the visual axis, exist, manual or surgical removal would be indicated. Otherwise, we recommend conventional treatments for eye injuries. Given this situation, patients should be closely monitored for detection of any worsening. If the condition does not resolve or even deteriorates, for the second stage, surgical removal of the stinger under local or generalized anesthesia is indicated.Keywords: bee sting, stinger, cornea, removal, management, surgery

  17. Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats

    Directory of Open Access Journals (Sweden)

    Lakshminarayanan R

    2014-05-01

    conformation of gelatin and the presence of gelatin decreased the hemolytic activity of polyenes. The polyene-loaded fiber mats were noncytotoxic to primary human corneal and sclera fibroblasts. The reduction of toxicity with complete retention of activity of the polyene antifungal-loaded gelatin fiber mats can provide new opportunities in the management of superficial skin infections. Keywords: fungal infections, electrospinning, antifungals, controlled release, drug–matrix interactions

  18. Turning the tide of corneal blindness.

    Science.gov (United States)

    Oliva, Matthew S; Schottman, Tim; Gulati, Manoj

    2012-01-01

    Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world's largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

  19. Turning the tide of corneal blindness

    Directory of Open Access Journals (Sweden)

    Matthew S Oliva

    2012-01-01

    Full Text Available Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world′s largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

  20. Clinical applications of corneal confocal microscopy

    Directory of Open Access Journals (Sweden)

    Mitra Tavakoli

    2008-06-01

    Full Text Available Mitra Tavakoli1, Parwez Hossain2, Rayaz A Malik11Division of Cardiovascular Medicine, University of Manchester and Manchester Royal Infirmary, Manchester, UK; 2University of Southampton, Southampton Eye Unit, Southampton General Hospital, Southampton, UKAbstract: Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowman’s layer, stroma, Descemet’s membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious conditions, corneal dystrophies and ecstasies, monitoring contact lens induced corneal changes and for pre and post surgical evaluation (PRK, LASIK and LASEK, flap evaluations and Radial Keratotomy, and penetrating keratoplasty. Most recently it has been used as a surrogate for peripheral nerve damage in a variety of peripheral neuropathies and may have potential in acting as a surrogate marker for endothelial abnormalities.Keywords: corneal confocal microscopy, cornea, infective keratitis, corneal dystrophy, neuropathy

  1. Crosslinked collagen-gelatin-hyaluronic acid biomimetic film for cornea tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang; Ren, Li, E-mail: psliren@scut.edu.cn; Wang, Yingjun, E-mail: imwangyj@163.com

    2013-01-01

    Cornea disease may lead to blindness and keratoplasty is considered as an effective treatment method. However, there is a severe shortage of donor corneas worldwide. This paper presents the crosslinked collagen (Col)-gelatin (Gel)-hyaluronic acid (HA) films developed by making use of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as the crosslinker. The test results on the physical and biological properties indicate that the CGH631 film (the mass ratio of Col:Gel:HA = 6:3:1) has appropriate optical performance, hydrophilicity and mechanical properties. The diffusion properties of the CGH631 film to NaCl and tryptophan are also satisfactory and the measured data are 2.43 Multiplication-Sign 10{sup -6} cm{sup 2}/s and 7.97 Multiplication-Sign 10{sup -7} cm{sup 2}/s, respectively. In addition, cell viability studies demonstrate that the CGH631 film has good biocompatibility, on which human corneal epithelial cells attached and proliferated well. This biocompatible film may have potential use in cornea tissue engineering. - Highlights: Black-Right-Pointing-Pointer Crosslinked collagen-gelatin-hyaluronic acid films were fabricated in this study. Black-Right-Pointing-Pointer The film had appropriate physical properties. Black-Right-Pointing-Pointer Diffusion coefficient of the film was comparable with the human cornea. Black-Right-Pointing-Pointer HCEC viability studies confirmed the biocompatibility of the film.

  2. Visual outcome after corneal transplantation for corneal perforation and iris prolapse in 37 horses

    DEFF Research Database (Denmark)

    Henriksen, Michala de Linde; Plummer, C. E.; Mangan, B.;

    2012-01-01

    We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation.......We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation....

  3. Recombinant gelatin and collagen from methylotrophic yeasts

    NARCIS (Netherlands)

    Bruin, de E.C.

    2002-01-01

    Based on its structural role and compatibility within the human body, collagen is a commonly used biomaterial in medical applications, such as cosmetic surgery, wound treatment and tissue engineering. Gelatin is in essence denatured and partly degraded collagen and is, as a result of

  4. Determination of corneal image-forming properties from corneal topography.

    Science.gov (United States)

    Maloney, R K; Bogan, S J; Waring, G O

    1993-01-01

    Keratometry provides useful information about the cornea's image-forming properties, such as corneal astigmatism, but is inaccurate on irregular corneas. Quantitative corneal topographic information is now obtainable on irregular corneas, but is difficult for the clinician to interpret. We developed a method to determine the spherical power, astigmatism, and topographic irregularity of a cornea by finding the best-fit spherocylinder that was closest to its measured topography. Keratometric measurements and two videokeratographs were gathered prospectively on 262 normal and abnormal corneas. The best-fit measurements of spherical power, astigmatism, and topographic irregularity were reproducible with one standard deviation of 0.75 diopter or better; agreement with keratometric measurements in normal eyes was good (0.60 diopter or better). Topographic irregularity averaged 0.1 diopter on precision spheres, 0.4 diopter on 146 normal eyes, 0.8 diopter on 29 eyes after radial keratotomy, 2.0 diopters on 58 eyes after penetrating keratoplasty, and 3.0 diopters on 29 eyes with advanced keratoconus. We conclude the following: basic corneal image-forming properties can be measured from videokeratographs; the properties can be determined, by our methods, on irregular corneas in which keratometry is unreliable; and topographic irregularity provides a measure of irregular astigmatism.

  5. Genetics Home Reference: lattice corneal dystrophy type I

    Science.gov (United States)

    ... corneal dystrophy type I lattice corneal dystrophy type I Enable Javascript to view the expand/collapse boxes. ... All Close All Description Lattice corneal dystrophy type I is an eye disorder that affects the clear, ...

  6. Immunoglobulins in granular corneal dystrophy Groenouw type I

    DEFF Research Database (Denmark)

    Møller, H U; Bojsen-Møller, M; Schrøder, H D

    1993-01-01

    Three patients with granular corneal dystrophy Groenouw type I underwent corneal grafting, and cryostat sections of the corneal buttons were examined immunohistochemically for immunoglobulins. Positive results were obtained for IgG, Kappa-, and Lambda chains with immunofluorescence technique...

  7. Polar Value Analysis of Corneal Astigmatism in Intrastromal Corneal Ring Segment Implantation

    OpenAIRE

    Chang Rae Rho; Min-Ji Kim; Choun-Ki Joo

    2016-01-01

    Purpose. To evaluate surgically induced astigmatism (SIA) and the average corneal power change in symmetric intrastromal corneal ring segment (ICRS) implantation. Methods. The study included 34 eyes of 34 keratoconus patients who underwent symmetric Intacs SK ICRS implantation. The corneal pocket incision meridian was the preoperative steep meridian. Corneal power data were obtained before and 3 months after Intacs SK ICRS implantation using scanning-slit topography. Polar value analysis was ...

  8. [Regeneration and fibrosis of corneal tissues].

    Science.gov (United States)

    Simirskiĭ, V N

    2014-01-01

    In this review, the features of the regeneration of corneal tissue and its disorders leading to the development of fibrosis are considered. The data on the presence of stem (clonogenic) cell pool in the corneal tissues (epithelium, endothelium, stroma) are given; these cells can serve as a source for regeneration of the tissues at injury or various diseases. The main steps of regeneration of corneal tissues and their disorders that lead to outstripping proliferation of myofibroblasts and secretion of extracellular matrix in the wound area and eventually cause the formation of connective tissue scar and corneal opacity are considered. Particular attention is given to the successes of translational medicine in the treatment of corneal tissue fibrosis. The methods of cell therapy aimed at the restoration of stem cell pool of corneal tissues are the most promising. Gene therapy provides more opportunities; one of its main objectives is the suppression of the myofibroblast proliferation responsible for the development of fibrosis.

  9. Modification of gelatin functionality for culinary applications by using transglutaminase

    DEFF Research Database (Denmark)

    Calvarro, Julia; Pérez-Palacios, Trinidad; Ruiz Carrascal, Jorge

    2016-01-01

    Porcine gelatin was subjected to the action of different amounts of commercial transglutaminase (TGase) and subsequently used to produce foams or gels. Foam stability at 20 °C and 80 °C, and thermal stability and instrumental texture of the gels were studied. Gelatin and TGase contents...... significantly increased the foam stability at both temperatures, but the effect of TGase was much more marked. Also both factors enhanced the thermal stability of gelatin gels, so that gels containing 3% of gelatin and 0.7% TGase were still gelled after 1 h at 80 °C, while any of the gelatin-based gels without...... TGase turned rapidly into liquid in less than 10 min at 80 °C. Hardness and chewiness of the gels were strongly enhanced by gelatin content, but very especially by TGase concentration. Gels tended to be less springy with increasing amounts of TGase. Modification of gelatin-based foams and gels...

  10. Inhibition by a selective IkappaB kinase-2 inhibitor of interleukin-1-induced collagen degradation by corneal fibroblasts in three-dimensional culture.

    Science.gov (United States)

    Kondo, Yukiko; Fukuda, Ken; Adachi, Tadafumi; Nishida, Teruo

    2008-11-01

    Corneal ulcer results from excessive collagen degradation in the corneal stroma. Interleukin (IL)-1 promotes this process by activating signaling molecules that include nuclear factor (NF)-kappaB and stimulating the synthesis of matrix metalloproteinases (MMPs) in corneal fibroblasts. NF-kappaB activation is mediated by phosphorylation of the inhibitor IkappaB by IkappaB kinase (IKK)-2 and consequent IkappaB degradation. The authors investigated the effects of the IKK-2 inhibitor [5-(p-fluorophenyl)-2-ureido]thiophene-3-carboxamide (TPCA-1) on collagen degradation by corneal fibroblasts. Rabbit corneal fibroblasts were cultured in three-dimensional collagen gels. Collagen degradation was evaluated by spectrophotometric quantitation of hydroxyproline in culture supernatants subjected to acid-heat hydrolysis. Expression of MMPs was evaluated by immunoblot analysis, gelatin zymography, and real-time reverse transcription polymerase chain reaction analysis. The phosphorylation and degradation of IkappaBalpha and the subcellular localization of NF-kappaB were examined by immunoblot and immunofluorescence analyses, respectively. IL-1beta-induced collagen degradation by corneal fibroblasts was inhibited by TPCA-1 in a concentration- and time-dependent manner. TPCA-1 inhibited the IL-1beta-induced expression of MMP-1, -3, and -9 in these cells at both the mRNA and protein levels and the IL-1beta-induced activation of pro-MMP-2. In contrast to dexamethasone, TPCA-1 inhibited the phosphorylation and degradation of IkappaBalpha and the nuclear translocation of NF-kappaB induced by IL-1beta. An IKK-2 inhibitor blocked IL-1beta-induced collagen degradation by corneal fibroblasts by inhibiting the activation of the NF-kappaB signaling pathway and the upregulation of MMPs. IKK-2 inhibitors are thus potential alternatives to dexamethasone for the treatment of corneal ulcer.

  11. Solubilization of bovine gelatin using power ultrasound: gelation without heating.

    Science.gov (United States)

    Farahnaky, Asgar; Zendeboodi, Fatemeh; Azizi, Rezvan; Mesbahi, Gholamreza; Majzoobi, Mahsa

    2017-04-01

    The aim of this study was to investigate the efficacy of power ultrasound without using any heating stage in solubilizeing gelatin dispersions, and to characterize the mechanical and microstructural properties of the resulting gels using texture analysis and scanning electron microscopy, respectively. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. For solubilising gelatin, an ultrasound equipment with a frequency of 20 kHz, amplitude of 100% and power range of 50-150 W was used. Aqueous gelatin dispersions (4% w/v) were subjected to ultrasound for different times (40-240 s) at a constant temperature of 13C. Applying ultrasound to gelatin dispersions caused increases in water absorption and water solubility of the hydrocolloid. The textural parameters of the resulting gelatin gels, increased with increasing time and power of ultrasound. Moreover, a generalized Maxwell model with three elements was used for calculating relaxation times of the gels. The microstructural observations by SEM showed that the structural cohesiveness of the gels increased by increasing ultrasonication time. Ultrasound-assisted solubilization of gelatin can have emerging implications for industrial uses in pharmaceuticals, food and non-food systems. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. Therefore, the use of gelatin as a hydrocolloid in food processings or pharmaceutical formulations which lack a heating step has been a technological and practical challenge. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. Ultrasound-assisted solubilisation of gelatin can have emerging implications for industrial uses in pharmaceuticals

  12. Obtaining corneal tissue for keratoplasty.

    Science.gov (United States)

    Navarro Martínez-Cantullera, A; Calatayud Pinuaga, M

    2016-10-01

    Cornea transplant is the most common tissue transplant in the world. In Spain, tissue donation activities depend upon transplant coordinator activities and the well-known Spanish model for organ and tissue donation. Tissue donor detection system and tissue donor evaluation is performed mainly by transplant coordinators using the Spanish model on donation. The evaluation of a potential tissue donor from detection until recovery is based on an exhaustive review of the medical and social history, physical examination, family interview to determine will of the deceased, and a laboratory screening test. Corneal acceptance criteria for transplantation have a wider spectrum than other tissues, as donors with active malignancies and infections are accepted for kearatoplasty in most tissue banks. Corneal evaluation during the whole process is performed to ensure the safety of the donor and the recipient, as well as an effective transplant. Last step before processing, corneal recovery, must be performed under standard operating procedures and in a correct environment. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  13. A native-like corneal construct using donor corneal stroma for tissue engineering.

    Directory of Open Access Journals (Sweden)

    Jing Lin

    Full Text Available Tissue engineering holds great promise for corneal transplantation to treat blinding diseases. This study was to explore the use of natural corneal stroma as an optimal substrate to construct a native like corneal equivalent. Human corneal epithelium was cultivated from donor limbal explants on corneal stromal discs prepared by FDA approved Horizon Epikeratome system. The morphology, phenotype, regenerative capacity and transplantation potential were evaluated by hematoxylin eosin and immunofluorescent staining, a wound healing model, and the xeno-transplantation of the corneal constructs to nude mice. An optically transparent and stratified epithelium was rapidly generated on donor corneal stromal substrate and displayed native-like morphology and structure. The cells were polygonal in the basal layer and became flattened in superficial layers. The epithelium displayed a phenotype similar to human corneal epithelium in vivo. The differentiation markers, keratin 3, involucrin and connexin 43, were expressed in full or superficial layers. Interestingly, certain basal cells were immunopositive to antibodies against limbal stem/progenitor cell markers ABCG2 and p63, which are usually negative in corneal epithelium in vivo. It suggests that this bioengineered corneal epithelium shared some characteristics of human limbal epithelium in vivo. This engineered epithelium was able to regenerate in 4 days following from a 4mm-diameter wound created by a filter paper soaked with 1 N NaOH. This corneal construct survived well after xeno-transplantation to the back of a nude mouse. The transplanted epithelium remained multilayer and became thicker with a phenotype similar to human corneal epithelium. Our findings demonstrate that natural corneal stroma is an optimal substrate for tissue bioengineering, and a native-like corneal construct has been created with epithelium containing limbal stem cells. This construct may have great potential for clinical use in

  14. Corneal tomography and biomechanics in primary pterygium.

    Science.gov (United States)

    Vanathi, M; Goel, Sahil; Ganger, Anita; Agarwal, Tushar; Dada, T; Khokhar, Sudarshan

    2017-05-13

    To study the Scheimpflug's imaging and corneal biomechanics in primary pterygium. A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer. Of the total 55 patients, mean age was 43.0 + 11.4 years (range: 20-72 years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21 + 0.20 and 0.12 + 0.15, respectively (p = 0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09 + 3.38/44.33 + 2.29 in pterygium eyes, 43.13 + 1.79/43.98 + 2.17 in control eyes (p  0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ = 0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ = 0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively). Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

  15. Electrochemical Characterization of Gelatine Derived Ceramics

    Directory of Open Access Journals (Sweden)

    Nowak A.P.

    2014-12-01

    Full Text Available New materials obtained by pyrolysis of gelatine (G and poly(1,2-dimethylsilazane (PSN (weight ratio: G/PSN 70/30 at temperatures 700 and 900 °C were characterized by SEM and Raman spectroscopy. The presence of ceramics influences on the cluster size of the materials. Electrochemical tests were performed by cyclic voltammetry and galvanostatic cyclic polarization. The capacity of G/PSN was 464 and 527 mAh/g for materials pyrolysed at 700 and 900 °C. The capacity fading was 1 % after 17th cycle for G/PSN at 900 °C. This value is higher of 185 mAh/g in comparison to capacity of gelatine pyrolysed at the same conditions.

  16. Simplified dichromated gelatin hologram recording process

    Science.gov (United States)

    Georgekutty, Tharayil G.; Liu, Hua-Kuang

    1987-01-01

    A simplified method for making dichromated gelatin (DCG) holographic optical elements (HOE) has been discovered. The method is much less tedious and it requires a period of processing time comparable with that for processing a silver halide hologram. HOE characteristics including diffraction efficiency (DE), linearity, and spectral sensitivity have been quantitatively investigated. The quality of the holographic grating is very high. Ninety percent or higher diffraction efficiency has been achieved in simple plane gratings made by this process.

  17. Corneal laceration caused by river crab

    Directory of Open Access Journals (Sweden)

    Vinuthinee N

    2015-01-01

    Full Text Available Naidu Vinuthinee,1,2 Anuar Azreen-Redzal,1 Jaafar Juanarita,1 Embong Zunaina2 1Department of Ophthalmology, Hospital Sultanah Bahiyah, Alor Setar, 2Department of Ophthalmology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia Abstract: A 5-year-old boy presented with right eye pain associated with tearing and photophobia of 1-day duration. He gave a history of playing with a river crab when suddenly the crab clamped his fingers. He attempted to fling the crab off, but the crab flew and hit his right eye. Ocular examination revealed a right eye corneal ulcer with clumps of fibrin located beneath the corneal ulcer and 1.6 mm level of hypopyon. At presentation, the Seidel test was negative, with a deep anterior chamber. Culture from the corneal scrapping specimen grew Citrobacter diversus and Proteus vulgaris, and the boy was treated with topical gentamicin and ceftazidime eyedrops. Fibrin clumps beneath the corneal ulcer subsequently dislodged, and revealed a full-thickness corneal laceration wound with a positive Seidel test and shallow anterior chamber. The patient underwent emergency corneal toileting and suturing. Postoperatively, he was treated with oral ciprofloxacin 250 mg 12-hourly for 1 week, topical gentamicin, ceftazidime, and dexamethasone eyedrops for 4 weeks. Right eye vision improved to 6/9 and 6/6 with pinhole at the 2-week follow-up following corneal suture removal. Keywords: corneal ulcer, pediatric trauma, ocular injury

  18. Corneal staining after treatment with topical tetracycline

    NARCIS (Netherlands)

    R. Lapid-Gortzak; C.P. Nieuwendaal; A.R. Slomovic; L. Spanjaard

    2006-01-01

    Purpose: The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline. Methods: A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of

  19. Corneal cellular proliferation and wound healing

    OpenAIRE

    Gan, Lisha

    2000-01-01

    Background. Cellular proliferation plays an important role in both physiological and pathological processes. Epithelial hyperplasia in the epithelium, excessive scar formation in retrocorneal membrane formation and neovascularization are examples of excessive proliferation of cornea cells. Lack of proliferative ability causes corneal degeneration. The degree of proliferative and metabolic activity will directly influence corneal transparency and very evidently refractive res...

  20. Corynebacterium macginleyi isolated from a corneal ulcer

    Directory of Open Access Journals (Sweden)

    Kathryn Ruoff

    2010-02-01

    Full Text Available We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT. To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.

  1. Photocrosslinkable Gelatin Hydrogel for Epidermal Tissue Engineering.

    Science.gov (United States)

    Zhao, Xin; Lang, Qi; Yildirimer, Lara; Lin, Zhi Yuan; Cui, Wenguo; Annabi, Nasim; Ng, Kee Woei; Dokmeci, Mehmet R; Ghaemmaghami, Amir M; Khademhosseini, Ali

    2016-01-01

    Natural hydrogels are promising scaffolds to engineer epidermis. Currently, natural hydrogels used to support epidermal regeneration are mainly collagen- or gelatin-based, which mimic the natural dermal extracellular matrix but often suffer from insufficient and uncontrollable mechanical and degradation properties. In this study, a photocrosslinkable gelatin (i.e., gelatin methacrylamide (GelMA)) with tunable mechanical, degradation, and biological properties is used to engineer the epidermis for skin tissue engineering applications. The results reveal that the mechanical and degradation properties of the developed hydrogels can be readily modified by varying the hydrogel concentration, with elastic and compressive moduli tuned from a few kPa to a few hundred kPa, and the degradation times varied from a few days to several months. Additionally, hydrogels of all concentrations displayed excellent cell viability (>90%) with increasing cell adhesion and proliferation corresponding to increases in hydrogel concentrations. Furthermore, the hydrogels are found to support keratinocyte growth, differentiation, and stratification into a reconstructed multilayered epidermis with adequate barrier functions. The robust and tunable properties of GelMA hydrogels suggest that the keratinocyte laden hydrogels can be used as epidermal substitutes, wound dressings, or substrates to construct various in vitro skin models.

  2. Gelatin-Based Materials in Ocular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    James B. Rose

    2014-04-01

    Full Text Available Gelatin has been used for many years in pharmaceutical formulation, cell culture and tissue engineering on account of its excellent biocompatibility, ease of processing and availability at low cost. Over the last decade gelatin has been extensively evaluated for numerous ocular applications serving as cell-sheet carriers, bio-adhesives and bio-artificial grafts. These different applications naturally have diverse physical, chemical and biological requirements and this has prompted research into the modification of gelatin and its derivatives. The crosslinking of gelatin alone or in combination with natural or synthetic biopolymers has produced a variety of scaffolds that could be suitable for ocular applications. This review focuses on methods to crosslink gelatin-based materials and how the resulting materials have been applied in ocular tissue engineering. Critical discussion of recent innovations in tissue engineering and regenerative medicine will highlight future opportunities for gelatin-based materials in ophthalmology.

  3. Biosynthesis and Characterization of Nanocellulose-Gelatin Films

    Directory of Open Access Journals (Sweden)

    Muenduen Phisalaphong

    2013-02-01

    Full Text Available A nanocellulose-gelatin (bacterial cellulose gelatin (BCG film was developed by a supplement of gelatin, at a concentration of 1%–10% w/v, in a coconut-water medium under the static cultivation of Acetobacter xylinum. The two polymers exhibited a certain degree of miscibility. The BCG film displayed dense and uniform homogeneous structures. The Fourier transform infrared spectroscopy (FTIR results demonstrated interactions between the cellulose and gelatin. Incorporation of gelatin into a cellulose nanofiber network resulted in significantly improved optical transparency and water absorption capacity of the films. A significant drop in the mechanical strengths and a decrease in the porosity of the film were observed when the supplement of gelatin was more than 3% (w/v. The BCG films showed no cytotoxicity against Vero cells.

  4. Synthesis, Characterization, and Biological Evaluation of Gelatin-based Scaffolds

    CERN Document Server

    Tronci, G

    2011-01-01

    This thesis presents the development of entropy-elastic gelatin based networks in the form of films or scaffolds. The materials have good prospects for biomedical applications, especially in the context of bone regeneration. Entropy-elastic gelatin based hydrogel films with varying crosslinking densities were prepared with tailored mechanical properties. Gelatin was covalently crosslinked in water above its sol gel transition, which suppressed the gelatin chain helicity. Amorphous films were prepared with tailorable degrees of swelling and wet state Young's modulus. The knowledge gained with this bulk material was transferred to the integrated process of foaming and crosslinking to obtain porous gelatin-based scaffolds. A gelatin solution was foamed in the presence of saponin and the resulting foam was fixed by chemical crosslinking with a diisocyanate. The scaffolds were analyzed in the dry state by micro computed tomography (\\mu CT, porosity: 65\\pm 11-73\\pm 14 vol.-%), and scanning electron microscopy (SEM,...

  5. Dorsally located corneal dermoid in a cat

    Directory of Open Access Journals (Sweden)

    Alexander J LoPinto

    2016-04-01

    Full Text Available Case summary A 2-month-old, male kitten was presented for evaluation of unilateral blepharospasm and epiphora involving the right eye. Ocular examination revealed conjunctivitis, a superficial corneal ulcer, reflex anterior uveitis and a haired mass within the dorsal cornea of the right eye. The mass was subsequently removed surgically via a lamellar keratectomy. Histologic evaluation of the mass via light microscopy revealed it to be comprised of normal-haired skin with mild inflammation. One week after surgical removal and medical management of the corneal ulcer, all ocular clinical signs had resolved with minimal corneal scarring. On re-examination 6 months following surgical excision of the mass, the kitten was noted to be comfortable with no significant corneal scarring. Relevance and novel information To our knowledge, this is the first case report of a dorsally located corneal dermoid in a cat.

  6. Corneal Topographical Changes Flollowing Strabismus Surgery

    Institute of Scientific and Technical Information of China (English)

    MaiGH; WangZ

    1999-01-01

    Purpose:To study corneal topographical changes after strabismus surgery.Methods:Computer-aided corneal topography was used in 43 strabismus patients(45 eyes)one or two days prior to and six or seven ays after strabismus surgery.The spherical and cylindrical equivalents were calculated based on the simulated keratometry.Results:After the surgery,only the changes at 3mm in the inferior quadrant were statistically significant.The changes at 3mm in the rest quadrants and the changes at 7mm were no significant.Significant changes in spherical equivalent were found post-operatively.neither the horizontal nor the verical meridional equivalent showed significant changes after surgery.Conclusions:The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

  7. Corneal neovascularization and contemporary antiangiogenic therapeutics.

    Science.gov (United States)

    Hsu, Chih-Chien; Chang, Hua-Ming; Lin, Tai-Chi; Hung, Kuo-Hsuan; Chien, Ke-Hung; Chen, Szu-Yu; Chen, San-Ni; Chen, Yan-Ting

    2015-06-01

    Corneal neovascularization (NV), the excessive ingrowth of blood vessels from conjunctiva into the cornea, is a common sequela of disease insult that can lead to visual impairment. Clinically, topical steroid, argon laser photocoagulation, and subconjunctival injection of bevacizumab have been used to treat corneal NV. Sometimes, the therapies are ineffective, especially when the vessels are large. Large vessels are difficult to occlude and easily recanalized. Scientists and physicians are now dedicated to overcoming this problem. In this article, we briefly introduce the pathogenesis of corneal NV, and then highlight the existing animal models used in corneal NV research-the alkali-induced model and the suture-induced model. Most of all, we review the potential therapeutic targets (i.e., vascular endothelial growth factor and platelet-derived growth factor) and their corresponding inhibitors, as well as the immunosuppressants that have been discovered in recent years by corneal NV studies.

  8. Creating 3D gelatin phantoms for experimental evaluation in biomedicine

    Directory of Open Access Journals (Sweden)

    Stein Nils

    2015-09-01

    Full Text Available We describe and evaluate a setup to create gelatin phantoms by robotic 3D printing. Key aspects are the large workspace, reproducibility and resolution of the created phantoms. Given its soft tissue nature, the gelatin is kept fluid during inside the system and we present parameters for additive printing of homogeneous, solid objects. The results indicate that 3D printing of gelatin can be an alternative for quickly creating larger soft tissue phantoms without the need for casting a mold.

  9. Corneal Regeneration by Deep Anterior Lamellar Keratoplasty (DALK Using Decellularized Corneal Matrix.

    Directory of Open Access Journals (Sweden)

    Yoshihide Hashimoto

    Full Text Available The purpose of this study is to demonstrate the feasibility of DALK using a decellularized corneal matrix obtained by HHP methodology. Porcine corneas were hydrostatically pressurized at 980 MPa at 10°C for 10 minutes to destroy the cells, followed by washing with EGM-2 medium to remove the cell debris. The HHP-treated corneas were stained with H-E to assess the efficacy of decellularization. The decellularized corneal matrix of 300 μm thickness and 6.0 mm diameter was transplanted onto a 6.0 mm diameter keratectomy wound. The time course of regeneration on the decellularized corneal matrix was evaluated by haze grading score, fluorescein staining, and immunohistochemistry. H-E staining revealed that no cell nuclei were observed in the decellularized corneal matrix. The decellularized corneal matrices were opaque immediately after transplantation, but became completely transparent after 4 months. Fluorescein staining revealed that initial migration of epithelial cells over the grafts was slow, taking 3 months to completely cover the implant. Histological sections revealed that the implanted decellularized corneal matrix was completely integrated with the receptive rabbit cornea, and keratocytes infiltrated into the decellularized corneal matrix 6 months after transplantation. No inflammatory cells such as macrophages, or neovascularization, were observed during the implantation period. The decellularized corneal matrix improved corneal transparency, and remodelled the graft after being transplanted, demonstrating that the matrix obtained by HHP was a useful graft for corneal tissue regeneration.

  10. First Identification of a Triple Corneal Dystrophy Association: Keratoconus, Epithelial Basement Membrane Corneal Dystrophy and Fuchs' Endothelial Corneal Dystrophy

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2014-09-01

    Full Text Available Purpose: To report the observation of a triple corneal dystrophy association consisting of keratoconus (KC, epithelial basement membrane corneal dystrophy (EBMCD and Fuchs' endothelial corneal dystrophy (FECD. Methods: A 55-year-old male patient was referred to our cornea service for blurred vision and recurrent foreign body sensation. He reported bilateral recurrent corneal erosions with diurnal visual fluctuations. He underwent corneal biomicroscopy, Scheimpflug tomography, in vivo HRT confocal laser scanning microscopy and genetic testing for TGFBI and ZEB1 mutations using direct DNA sequencing. Results: Biomicroscopic examination revealed the presence of subepithelial central and paracentral corneal opacities. The endothelium showed a bilateral flecked appearance, and the posterior corneal curvature suggested a possible concomitant ectatic disorder. Corneal tomography confirmed the presence of a stage II KC in both eyes. In vivo confocal laser scanning microscopy revealed a concomitant bilateral EBMCD with hyperreflective deposits in basal epithelial cells, subbasal Bowman's layer microfolds and ridges with truncated subbasal nerves as pseudodendritic elements. Stromal analysis revealed honeycomb edematous areas, and the endothelium showed a strawberry surface configuration typical of FECD. The genetic analysis resulted negative for TGFBI mutations and positive for a heterozygous mutation in exon 7 of the gene ZEB1. Conclusion: This is the first case reported in the literature in which KC, EBMCD and FECD are present in the same patient and associated with ZEB1 gene mutation. The triple association was previously established by means of morphological analysis of the cornea using corneal Scheimpflug tomography and in vivo HRT II confocal laser scanning microscopy.

  11. Effect of maltodextrin on characteristics and antioxidative activity of spray-dried powder of gelatin and gelatin hydrolysate from scales of spotted golden goatfish.

    Science.gov (United States)

    Chuaychan, Sira; Benjakul, Soottawat

    2016-09-01

    Characteristics and antioxidative activity of gelatin and gelatin hydrolysate powders from scale of spotted golden goatfish using maltodextrin as a carrier agent at different ratios [1:0, 2:1, 1:1 and 1:2 (w/w)] were investigated. Gelatin hydrolysates with 40 % degree of hydrolysis exhibited the highest antioxidative activity. With increasing maltodextrin proportions, the resulting powders showed an increase in yields, total sugar content and whiteness with coincidental decrease in [Formula: see text], [Formula: see text]-values and browning intensity. Solubility of gelatin powder increased with increase in maltodextrin proportion. Gelatin powder was spherical with smooth surface of hydrolysate varied, regardless of maltodextrin levels. Gelatin hydrolysate powder form, uniform agglomerates when maltodextrin was incorporated. DPPH and ABTS radical scavenging activities and ferric-reducing antioxidant power of gelatin and gelatin hydrolysate decreased when maltodextrin was used as a carrier agent. Thus, maltodextrin levels directly affected characteristics and antioxidative activity of gelatin and gelatin hydrolysate powders.

  12. Factors Affecting Corneal Hysteresis in Taiwanese Adults

    Institute of Scientific and Technical Information of China (English)

    Jia-Kang Wang; Tzu-Lun Huang; Pei-Yuan Su; Pei-Yao Chang

    2015-01-01

    Purpose: To investigate the correlation of various corneal hysteresis (CH) factors in Chinese adults. Methods: From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the study. Goldmann-correlated intraocular pressure (IOPG) and CH were measured using an ocular response analyzer (ORA). Central corneal thickness was measured using the ORA’s in-tegrated handheld ultrasonic pachymeter. The IOLMaster was used to obtain the ocular biometric measurements including axial length, anterior chamber depth, and keratometric values. The Pearson correlation coefficient was used to test correla-tions between CH and quantitative factors. The chi-square test was used to detect differences in categorical values. Results: Longer axial length (P=0.0001), lower IOPG (P=0.03), older age(P=0.003),and thinner central corneal thick-ness (P=0.0001) were significantly associated with lower CH. The anterior chamber depth (P=0.34), gender (P=0.23), and corneal curvature (P=0.18) had no relationship to CH. Conclusion:Various factors including axial length, intraocular pressure, age, and central corneal thickness can affect measure-ment of corneal biomechanical properties in Chinese adults. But the anterior chamber depth, gender, and corneal curvature were irrelevant to CH.

  13. Corneal sensitivity in five horse breeds

    Directory of Open Access Journals (Sweden)

    Eunice Santos de Andrade

    Full Text Available ABSTRACT: This study aimed to determine and compare corneal sensitivity values in different regions of the cornea in five horse breeds. One hundred and forty five healthy horses, adults of both sexes, of the following breeds - Arabian horse (AH; n=20, Mangalarga Marchador (MM; n=50, Pure Blood Lusitano (PBL; n=35, Quarter Horse (QH; n=20, Brazilian Sport Horse (BSH; n=20-were investigated. Corneal touch threshold (CTT was measured with a Cochet-Bonnet esthesiometer in five different corneal regions. Measurements of the median central CTT were: 4.50±0.50cm (AH, 3.50±0.56cm (MM, 3.00±0.25cm (PBL, 2.50±0.44cm (QH and 2.50±0.00cm (BSH. The central region was the most sensitive and the dorsal region the least sensitive corneal region for all breeds. CTT values differed for corneal regions and horse breeds. The CTT values were different among the corneal regions and the horse breeds. Arabian horses presented higher sensitivity values being the most sensitive in all of the corneal regions.

  14. Corneal topographic changes following retinal surgery

    Directory of Open Access Journals (Sweden)

    Pandey RM

    2004-08-01

    Full Text Available Abstract Background To study the effect of retinal/ vitreoretinal surgeries on corneal elevations. Methods Patients who underwent retinal/ vitreoretinal surgeries were divided into 3 groups. Scleral buckling was performed in 11 eyes (Group 1. In 8 (25% eyes, vitreoretinal surgery was performed along with scleral buckling (Group 2. In 12 eyes, pars plana vitrectomy was performed for vitreous hemorrhage (Group 3. An encircling element was used in all the eyes. The parameters evaluated were best-corrected visual acuity (BCVA, change in axial length, and corneal topographic changes on Orbscan topography system II, preoperative and at 12 weeks following surgery. Results There was a statistically significant increase in anterior corneal elevation in all the three groups after surgery (p = 0.003, p = 0.008 & p = 0.003 respectively. The increase in posterior corneal elevation was highly significant in all the three groups after surgery (p = 0.0000, p = 0.0001 & p = 0.0001 respectively. The increase in the posterior corneal elevation was more than the increase in the anterior elevation and was significant statistically in all the three groups (group I: p = 0.02; group II: p = 0.01; group III: p = 0.008. Conclusions Retinal/ vitreoretinal surgeries cause a significant increase in the corneal elevations and have a greater effect on the posterior corneal surface.

  15. Differences between real and predicted corneal shapes after aspherical corneal ablation

    Science.gov (United States)

    Anera, Rosario G.; Villa, César; Jiménez, José R.; Gutiérrez, Ramón; Jiménez del Barco, Luis

    2005-07-01

    We study the differences between real and expected corneal shapes, using an aspherical ablation algorithm with a known equation and avoiding the limitation imposed by most studies of refractive surgery in which the ablation equations are not known. We have calculated the theoretical corneal shape predicted by this algorithm, comparing this shape with the real corneal topography. The results indicate that the deviations that appear in the corneal shape are significant for visual performance and for the correction of eye aberrations. If we include in this analysis the effect of reflection losses and nonnormal incidence on the cornea, we can reduce corneal differences, but they will remain significant. These results confirm that it is essential to minimize corneal differences to achieve effective correction in refractive surgery.

  16. Graphene oxide decorated electrospun gelatin nanofibers: Fabrication, properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Jalaja, K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India); Sreehari, V.S. [Indian Institute of Science Education and Research Bhopal, Bhauri, Madhya Pradesh 462066 (India); Kumar, P.R. Anil [Tissue culture laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Thiruvananthapuram, Kerala 695 012 (India); Nirmala, R. James, E-mail: nirmala@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India)

    2016-07-01

    Gelatin nanofiber fabricated by electrospinning process is found to mimic the complex structural and functional properties of natural extracellular matrix for tissue regeneration. In order to improve the physico-chemical and biological properties of the nanofibers, graphene oxide is incorporated in the gelatin to form graphene oxide decorated gelatin nanofibers. The current research effort is focussed on the fabrication and evaluation of physico-chemical and biological properties of graphene oxide-gelatin composite nanofibers. The presence of graphene oxide in the nanofibers was established by transmission electron microscopy (TEM). We report the effect of incorporation of graphene oxide on the mechanical, thermal and biological performance of the gelatin nanofibers. The tensile strength of gelatin nanofibers was increased from 8.29 ± 0.53 MPa to 21 ± 2.03 MPa after the incorporation of GO. In order to improve the water resistance of nanofibers, natural based cross-linking agent, namely, dextran aldehyde was employed. The cross-linked composite nanofibers showed further increase in the tensile strength up to 56.4 ± 2.03 MPa. Graphene oxide incorporated gelatin nanofibers are evaluated for bacterial activity against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria and cyto compatibility using mouse fibroblast cells (L-929 cells). The results indicate that the graphene oxide incorporated gelatin nanofibers do not prevent bacterial growth, nevertheless support the L-929 cell adhesion and proliferation. - Highlights: • Graphene oxide nano reinforced gelatin nanofibers are fabricated by electrospinning. • Graphene oxide (0.5%) loading resulted in increased tensile strength. • GO/gelatin nanofibers are cross-linked with dextran aldehyde. • Composite nanofibers favoured adhesion of L-929 cells. • GO/gelatin mats do not prevent bacterial growth.

  17. Expression of MMP-2, MT1-MMP, and TIMP-2 by cultured rabbit corneal fibroblasts under mechanical stretch.

    Science.gov (United States)

    Liu, Chengxing; Feng, Pengfei; Li, Xiaona; Song, Jie; Chen, Weiyi

    2014-08-01

    Refractive surgery not only leads to tissue injury but also evokes mechanical stress increase of the cornea. How the mechanical stress affects the corneal matrix remodeling, specifically, matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of metalloproteinases; TIMPs) is not well understood. In this study, cultured rabbit corneal fibroblasts in vitro were subjected to regimen of 5%, 10%, or 15% equibiaxial stretch at 0.1 Hz for 3 or 24 h. MMP-2 protein level was measured by gelatin zymography and Western blotting. MMP-2, membrane type 1 MMP (MT1-MMP), and TIMP-2 mRNA levels were quantified by real-time quantitative PCR. Extracellular regulated protein kinase (ERK) phosphorylation protein levels were assessed by Western blotting. Our results showed that a 15% stretch resulted in increases in MMP-2 protein, MMP-2 mRNA, and MT1-MMP mRNA levels, but a decrease in TIMP-2 mRNA level. However, a 5% stretch caused decreases in MMP-2 protein and mRNA level, but an increase in TIMP-2 mRNA level, and no change in MT1-MMP mRNA level. A 15% stretch also caused a significant increase in ERK1/2 phosphorylation. Inhibition of the mitogenactivated protein kinase (MEK) pathway with PD98059 attenuated stretch-induced increase in MMP-2 production and ERK activity. These results suggest that small-magnitude stretching may promote corneal matrix synthetic events, whereas large-magnitude stretching promotes corneal matrix degradation by changing the balance between MMPs and TIMPs in corneal fibroblasts. Large-magnitude stretch-induced increase in pro-MMP-2 production was in an ERK-dependent manner. © 2014 by the Society for Experimental Biology and Medicine.

  18. Morphological evaluation of normal human corneal epithelium

    DEFF Research Database (Denmark)

    Ehlers, Niels; Heegaard, Steffen; Hjortdal, Jesper

    2010-01-01

    PURPOSE: The human corneal epithelium is usually described as a 50-µm-thick layer of regular stratified squamous non-keratinized cells with a thickness of 5-7 cells. The purpose of this study is systemically to revisit the histopathological appearance of 100 corneas. METHODS: 5-µm-thick sections...... in Bowman's membrane. No intraepithelial microcysts, as found in Meesmann corneal dystrophy, were observed. CONCLUSION: The total corneal thickness was higher than reported in in vivo studies and with a wider variation. This may be an effect of uncontrolled swelling and dehydration during preparation...

  19. Polar Value Analysis of Corneal Astigmatism in Intrastromal Corneal Ring Segment Implantation

    Science.gov (United States)

    Rho, Chang Rae; Kim, Min-Ji

    2016-01-01

    Purpose. To evaluate surgically induced astigmatism (SIA) and the average corneal power change in symmetric intrastromal corneal ring segment (ICRS) implantation. Methods. The study included 34 eyes of 34 keratoconus patients who underwent symmetric Intacs SK ICRS implantation. The corneal pocket incision meridian was the preoperative steep meridian. Corneal power data were obtained before and 3 months after Intacs SK ICRS implantation using scanning-slit topography. Polar value analysis was used to evaluate the SIA. Hotelling's trace test was used to compare intraindividual changes. Results. Three months postoperatively, the combined mean polar value for SIA changed significantly (Hotelling's T2 = 0.375; P = 0.006). The SIA was 1.54 D at 99° and the average corneal power decreased significantly by 3.8 D. Conclusion. Intacs SK ICRS placement decreased the average corneal power and corneal astigmatism compared to the preoperative corneal power and astigmatism when the corneal pocket incision was made at the preoperative steep meridian. PMID:27795856

  20. Polar Value Analysis of Corneal Astigmatism in Intrastromal Corneal Ring Segment Implantation

    Directory of Open Access Journals (Sweden)

    Chang Rae Rho

    2016-01-01

    Full Text Available Purpose. To evaluate surgically induced astigmatism (SIA and the average corneal power change in symmetric intrastromal corneal ring segment (ICRS implantation. Methods. The study included 34 eyes of 34 keratoconus patients who underwent symmetric Intacs SK ICRS implantation. The corneal pocket incision meridian was the preoperative steep meridian. Corneal power data were obtained before and 3 months after Intacs SK ICRS implantation using scanning-slit topography. Polar value analysis was used to evaluate the SIA. Hotelling’s trace test was used to compare intraindividual changes. Results. Three months postoperatively, the combined mean polar value for SIA changed significantly (Hotelling’s T2=0.375; P=0.006. The SIA was 1.54 D at 99° and the average corneal power decreased significantly by 3.8 D. Conclusion. Intacs SK ICRS placement decreased the average corneal power and corneal astigmatism compared to the preoperative corneal power and astigmatism when the corneal pocket incision was made at the preoperative steep meridian.

  1. Graphene oxide decorated electrospun gelatin nanofibers: Fabrication, properties and applications.

    Science.gov (United States)

    Jalaja, K; Sreehari, V S; Kumar, P R Anil; Nirmala, R James

    2016-07-01

    Gelatin nanofiber fabricated by electrospinning process is found to mimic the complex structural and functional properties of natural extracellular matrix for tissue regeneration. In order to improve the physico-chemical and biological properties of the nanofibers, graphene oxide is incorporated in the gelatin to form graphene oxide decorated gelatin nanofibers. The current research effort is focussed on the fabrication and evaluation of physico-chemical and biological properties of graphene oxide-gelatin composite nanofibers. The presence of graphene oxide in the nanofibers was established by transmission electron microscopy (TEM). We report the effect of incorporation of graphene oxide on the mechanical, thermal and biological performance of the gelatin nanofibers. The tensile strength of gelatin nanofibers was increased from 8.29±0.53MPa to 21±2.03MPa after the incorporation of GO. In order to improve the water resistance of nanofibers, natural based cross-linking agent, namely, dextran aldehyde was employed. The cross-linked composite nanofibers showed further increase in the tensile strength up to 56.4±2.03MPa. Graphene oxide incorporated gelatin nanofibers are evaluated for bacterial activity against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria and cyto compatibility using mouse fibroblast cells (L-929 cells). The results indicate that the graphene oxide incorporated gelatin nanofibers do not prevent bacterial growth, nevertheless support the L-929 cell adhesion and proliferation.

  2. Gelatin-Pectin Composite Films from Polyion Complex Hydrogels

    Science.gov (United States)

    Composite films from gelatin and low-methoxyl pectin were prepared by either ionic complexation or covalent cross-linking. The ionic interactions between positively charged gelatin and negatively charged pectin produced physically reversible hydrogels. The resultant homogeneous gels had improved mec...

  3. Covalently immobilized gelatin gradients within three-dimensional porous scaffolds

    Institute of Scientific and Technical Information of China (English)

    WU JinDan; TAN HuaPing; LI LinHui; GAO ChangYou

    2009-01-01

    A stable gelatin gradient providing continuous increment of signaling for cell adhesion and proliferation was fabricated within 3D poly(L-lactic acid) (PLLA) scaffolds. The porous PLLA scaffold fabricated by NaCI particle leaching was vertically fixed on a glass vial. 1,6-Hexanediamine/propanol solution was continuously injected into the vial by a micropump to aminolyze the PLLA scaffold. As a result of reaction time difference,the introduced-NH2 groups increased continuously along with the longitude of the PLLA scaffold in the z-direction. After covalent immobilization of gelatin by glutaraldehyde coupling,the gelatin gradient scaffold was thus obtained. In vitro chondrocyte culture showed that the cells had higher viability and more extending morphology in the gelatin gradient scaffold than that in the uniform gelatin control.

  4. Gelatin Functionalization of Biomaterial Surfaces: Strategies for Immobilization and Visualization

    Directory of Open Access Journals (Sweden)

    Peter Dubruel

    2011-01-01

    Full Text Available In the present work, the immobilization of gelatin as biopolymer on two types of implantable biomaterials, polyimide and titanium, was compared. Both materials are known for their biocompatibility while lacking cell-interactive behavior. For both materials, a pre-functionalization step was required to enable gelatin immobilization. For the polyimide foils, a reactive succinimidyl ester was introduced first on the surface, followed by covalent grafting of gelatin. For the titanium material, methacrylate groups were first introduced on the Ti surface through a silanization reaction. The applied functionalities enabled the subsequent immobilization of methacrylamide modified gelatin. Both surface modified materials were characterized in depth using atomic force microscopy, static contact angle measurements, confocal fluorescence microscopy, attenuated total reflection infrared spectroscopy and X-ray photo-electron spectroscopy. The results indicated that the strategies elaborated for both material classes are suitable to apply stable gelatin coatings. Interestingly, depending on the material class studied, not all surface analysis techniques are applicable.

  5. Surgical compensation of presbyopia with corneal inlays.

    Science.gov (United States)

    Konstantopoulos, Aris; Mehta, Jodhbir S

    2015-05-01

    Presbyopia, the physiological change in near vision that develops with ageing, gradually affects individuals older than 40 years and is a growing cause of visual disability due to ageing demographics of the global population. The routine use of computers and 'smartphones', combined with the affluence of the 'baby boomers' generation has set high standards for near vision correction. Corneal inlays are a relatively new treatment modality that is effective at compensating for presbyopia. The dimensions of these devices vary from 2 to 3.8 mm in diameter and 5 to 32 μm in thickness. They are implanted in the anterior corneal stroma of the non-dominant eye, most commonly, in a femtosecond laser created corneal pocket. They improve near vision by increasing the depth of focus, creating a hyper-prolate region of increased central cornea power or providing a refractive add power. This article reviews the literature on the efficacy and safety of corneal inlays.

  6. Conjunctival intraepithelial neoplasia with corneal furrow degeneration

    Directory of Open Access Journals (Sweden)

    Pukhraj Rishi

    2014-01-01

    Full Text Available A 68-year-old man presented with redness of left eye since six months. Examination revealed bilateral corneal furrow degeneration. Left eye lesion was suggestive of conjunctival squamous cell carcinoma, encroaching on to cornea. Anterior segment optical coherence tomography (AS-OCT confirmed peripheral corneal thinning. Fluorescein angiography confirmed intrinsic vascularity of lesion. Patient was managed with "no touch" surgical excision, dry keratectomy without alcohol, cryotherapy, and primary closure. Pathologic examination of removed tissue confirmed clinical diagnosis. Management of this particular case required modification of standard treatment protocol. Unlike the alcohol-assisted technique of tumor dissection described, ethyl alcohol was not used for risk of corneal perforation due to underlying peripheral corneal thinning. Likewise, topical steroids were withheld in the post-operative period. Three weeks post-operatively, left eye was healing well. Hence, per-operative usage of absolute alcohol and post-operative use of topical steroids may be best avoided in such eyes.

  7. Effect of aggregation behavior of gelatin in aqueous solution on the grafting density of gelatin modified with glycidol.

    Science.gov (United States)

    Xu, Jing; Li, Tian-Duo; Tang, Xiao-Long; Qiao, Cong-De; Jiang, Qing-Wei

    2012-06-15

    The effect of aggregation behavior of gelatin in aqueous solution on the grafting density of glycidol grafted gelatin polymers (GGG polymers) was investigated. The grafting density was measured using the Van Slyke method by calculating the conversion rate of free - NH(2) groups of gelatin. The conversion rate reached peak values at 6% and 14% of the gelatin aqueous solution. SEM micrographs displayed a series of structural transitions (i.e., spherical, spindle, butterfly, irregular and dendritic aggregates) at varying concentrations from 2% to 16% (w/w) at an interval of 2% (w/w). The spindle aggregates reappeared at the concentrations of 6% and 14%. Viscosity measurements indicated that the physicochemical properties of the gelatin solution had changed with increasing concentration. UV and CD analysis indicated that hydrophobic interactions competed with hydrogen bonding, and the random coils partly transformed to β-sheet structure by changing the concentration. Zeta potential and pH data confirmed the increasing electrostatic repulsion associated with increasing the hydrophobic region. XPS analysis revealed that the elemental composition of the gelatin particle surface changed with variation in the aggregate structure, determining the monotonic variation of the grafting density with increasing concentration. Results demonstrate that aggregation behavior of gelatin in aqueous solution plays a crucial role in deciding the grafting density of gelatin modified products.

  8. Properties of electrospun pollock gelatin/poly(vinyl alcohol) and pollock gelatin/poly(lactic acid) fibers

    Science.gov (United States)

    Pollock gelatin/poly(vinyl alcohol) (PVA) fibers were electrospun using deionized water as the solvent and pollock gelatin/poly(lactic acid) (PLA) fibers were electrospun using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. The chemical, thermal, and thermal stability properties were exami...

  9. The Dynamic Behaviour of Ballistic Gelatin

    Science.gov (United States)

    Shepherd, C. J.; Appleby-Thomas, G. J.; Hazell, P. J.; Allsop, D. F.

    2009-12-01

    In order to characterise the effect of projectiles it is necessary to understand the mechanism of both penetration and resultant wounding in biological systems. Porcine gelatin is commonly used as a tissue simulant in ballistic tests because it elastically deforms in a similar manner to muscular tissue. Bullet impacts typically occur in the 350-850 m/s range; thus knowledge of the high strain-rate dynamic properties of both the projectile and target materials are desirable to simulate wounds. Unlike projectile materials, relatively little data exists on the dynamic response of flesh simulants. The Hugoniot for a 20 wt.% porcine gelatin, which exhibits a ballistic response similar to that of human tissues at room temperature, was determined using the plate-impact technique at impact velocities of 75-860 m/s. This resulted in impact stresses around three times higher than investigated elsewhere. In US-uP space the Hugoniot had the form US = 1.57+1.77 uP, while in P-uP space it was essentially hydrodynamic. In both cases this was in good agreement with the limited available data from the literature.

  10. Corneal topography and soft contact lens fit.

    Science.gov (United States)

    Young, Graeme; Schnider, Cristina; Hunt, Chris; Efron, Suzanne

    2010-05-01

    To determine which ocular topography variables affect soft contact lens fit. Fifty subjects each wore three pairs of soft lenses in random succession (Vistakon Acuvue 2, Vistakon Acuvue Advance, Ciba Vision Night & Day), and various aspects of lens fit were evaluated. The steeper base curves of each type were worn in one eye and the flatter base curves in the other eye. Corneal topography data were collected using a Medmont E300 corneal topographer (Camberwell, Australia). Corneal curvature, shape factor (SF), and corneal height were measured over a 10 mm chord and also over the maximum measurable diameter. These were measured in the horizontal, vertical, steepest, and flattest meridians. With each lens type, the steeper base curve provided the best fit on the greatest proportion of eyes and the significant differences in various aspects of fit were noted between base curves. For each lens type, there was no significant difference in mean K-reading between those eyes best fit with the steeper base curve and those eyes best fit with the flatter base curve. Two of the lenses showed a positive correlation between centration and horizontal corneal height (maximum), whereas one lens showed a negative correlation between centration and horizontal SF (SF = e). Several lenses showed a positive correlation between post-blink movement and horizontal or vertical corneal SF. The measurement of corneal topography using current Placido disc instrumentation allows a better prediction of soft lens fit than by keratometry, but it is not reliable enough to enable accurate selection of the best fitting base curve. Some correlations are evident between corneal measurements; however, trial fitting remains the method of choice for selection of soft lens base curve.

  11. Serological profile of candidates for corneal donation

    OpenAIRE

    Adroaldo Lunardelli; Richard Beraldini Alvarenga; Maria Luiza Assmann; Dário Eduardo de Lima Brum; Mirna Adolfina Barison

    2014-01-01

    Objetive: The purpose of this study is to map the serological profile of candidates to corneal donation at Irmandade Santa Casa de Misericórdia de Porto Alegre, identifying the percentage of disposal by serology and the marker involved. Methods: There have been analised – retrospectively – the results of serology of all corneal donors, made between the period of 1st january 2006 and 31st december 2012. Data analised were related to age, gender and the results of serology pert...

  12. Asphericity analysis using corneal wavefront and topographic meridional fits

    Science.gov (United States)

    Arba-Mosquera, Samuel; Merayo-Lloves, Jesús; de Ortueta, Diego

    2010-03-01

    The calculation of corneal asphericity as a 3-D fit renders more accurate results when it is based on the corneal wavefront aberrations rather than on the corneal topography of the principal meridians. A more accurate prediction could be obtained for hyperopic treatments compared to myopic treatments. We evaluate a method to calculate corneal asphericity and asphericity changes after refractive surgery. Sixty eyes of 15 consecutive myopic patients and 15 consecutive hyperopic patients (n=30 each) are retrospectively evaluated. Preoperative and 3-month-postoperative topographic and corneal wavefront analyses are performed using corneal topography. Ablations are performed using a laser with an aberration-free profile. Topographic changes in asphericity and corneal aberrations are evaluated for a 6-mm corneal diameter. The induction of corneal spherical aberrations and asphericity changes correlates with the achieved defocus correction. Preoperatively as well as postoperatively, asphericity calculated from the topography meridians correlates with asphericity calculated from the corneal wavefront in myopic and hyperopic treatments. A stronger correlation between postoperative asphericity and the ideally expected/predicted asphericity is obtained based on aberration-free assumptions calculated from corneal wavefront values rather than from the meridians. In hyperopic treatments, a better correlation can be obtained compared to the correlation in myopic treatments. Corneal asphericity calculated from corneal wavefront aberrations represents a 3-D fit of the corneal surface; asphericity calculated from the main topographic meridians represents a 2-D fit of the principal corneal meridians. Postoperative corneal asphericity can be calculated from corneal wavefront aberrations with higher fidelity than from corneal topography of the principal meridians. Hyperopic treatments show a greater accuracy than myopic treatments.

  13. Update on pathologic diagnosis of corneal infections and inflammations

    Directory of Open Access Journals (Sweden)

    Geeta K Vemuganti

    2011-01-01

    Full Text Available One of the most frequent types of corneal specimen that we received in our pathology laboratory is an excised corneal tissue following keratoplasty. Several of these cases are due to corneal infections or the sequelae, like corneal scar. Advances in the histological and molecular diagnosis of corneal infections and inflammations have resulted in rapid and accurate diagnosis of the infectious agent and in the overall understanding of the mechanisms in inflammatory diseases of the cornea. This review provides an update of histopathological findings in various corneal infections and inflammations.

  14. Survival and integration of tissue-engineered corneal stroma in a model of corneal ulcer.

    Science.gov (United States)

    Zhang, Chao; Nie, Xin; Hu, Dan; Liu, Yuan; Deng, Zhihong; Dong, Rui; Zhang, Yongjie; Jin, Yan

    2007-08-01

    Tissue-engineered replacement of diseased or damaged tissue has become a reality for some types of tissue, such as skin and cartilage. Tissue-engineered corneal stroma represents a promising concept to overcome the limitations of cornea replacement with allograft. In this study, porcine cornea was decellularized by a series of extraction methods, and the in vivo biocompatibility of the scaffold was measured subcutaneously in rabbits (n = 8). These were not acutely rejected and no abscesses were observed by hematoxylin and eosin staining at the 8th week, indicating that the scaffolds had good biocompatibility. To investigate the potential value of clinical applications, rabbit stromal keratocytes were implanted onto decellularized scaffolds to fabricate tissue-engineered corneal stroma. Allograft, tissue-engineered corneal stroma, or scaffolds were implanted into a model of corneal ulcer. The survival and reconstruction of corneal transplantation were morphologically evaluated by light and electron microscopy until the 32nd week after implantation. Experiments involving transplantation indicated that the epithelial and stromal defect healed quickly, with improvement in corneal clarity. The integration of the graft was accompanied by neurite ingrowth from the host tissue. By 16 weeks after transplantation, the cornea had gradually regained an intact state similar to that of normal cornea. Our results demonstrate that the tissue-engineered corneal stroma with allogenetic cells is a promising therapeutic method for corneal injury.

  15. Gelation, oxygen permeability, and mechanical properties of mammalian and fish gelatin films.

    Science.gov (United States)

    Avena-Bustillos, R J; Chiou, B; Olsen, C W; Bechtel, P J; Olson, D A; McHugh, T H

    2011-09-01

    The objective of this study was to evaluate the gelation, thermal, mechanical, and oxygen permeability properties of different mammalian, warm- and cold-water fish gelatin solutions and films. Mammalian gelatin solutions had the highest gel set temperatures, followed by warm-water fish and then cold-water fish gelatin solutions. These differences were related to concentrations of imino acids present in each gelatin, with mammalian gelatin having the highest and cold-water fish gelatin having the lowest concentrations. Mammalian and warm-water fish gelatin films contained helical structures, whereas cold-water fish gelatin films were amorphous. This was due to the films being dried at room temperature (23 °C), which was below or near the gelation temperatures of mammalian and warm-water fish gelatin solutions and well above the gelation temperature of cold-water fish gelatin solutions. Tensile strength, percent elongation, and puncture deformation were highest in mammalian gelatin films, followed by warm-water fish gelatin film and then by cold-water fish gelatin films. Oxygen permeability values of cold-water fish gelatin films were significantly lower than those for mammalian gelatin films. These differences were most likely due to higher moisture sorption in mammalian gelatin films, leading to higher oxygen diffusivity. Journal of Food Science © 2011 Institute of Food Technologists® No claim to original US government works.

  16. Ultrasound biomicroscopy confirmation of corneal overriding due to improper suturing of full-thickness corneal laceration

    Directory of Open Access Journals (Sweden)

    Murat Kucukevcilioglu

    2014-12-01

    Full Text Available We herein present a case with corneal overriding due to improper suturing of a full-thickness corneal laceration. There was a 2.5-mm difference between horizontal and vertical white-to-white measurements in the cornea. However, slit lamp examination failed to demonstrate the exact architecture of the laceration. Ultrasound biomicroscopy defined the wound edges thoroughly and confirmed the presence of corneal overriding. Six weeks after suture enhancement, the abnormal oval appearance of the cornea was absent and correct apposition of the corneal edges was seen on ultrasound biomicroscopy. Ultrasound biomicroscopy can be used in preoperative surgical planning of cases with complicated corneal lacerations. It can be used to adjust and enhance wound architecture in eyes with penetrating injury.

  17. Effects of Gelatinization of Enteral Nutrients on Human Gastric Emptying.

    Science.gov (United States)

    Kawasaki, Naruo; Urashima, Mitsuyoshi; Odaira, Hironori; Noro, Takuji; Suzuki, Yutaka

    2010-06-01

    Gastrointestinal side effects, particularly diarrhea, are still the main reasons for discontinuation of enteral nutrition. Gelatinization of liquid meal for the prevention of diarrhea has been reported as effective. The purpose of this study was to investigate the effects of gelatinization of liquid meal on gastric emptying. Ten healthy volunteers were studied two times, with 2-week interval between tests. The total calorific value was set at 225 kcal, and 3 test meals were prepared: liquid meal and 2 types of gelatinized meals. These 2 types of gelatinized meals are different viscosity. (13)C-sodium acetate (100 mg) was thoroughly mixed, and exhaled air was sampled. The results of gastric emptying were expressed as the time of peak excretion (Tmax), and absorption was expressed as the area under the (13)CO2 curve up to Tmax (AUC-Tmax). At the same time, blood samples were collected to measure levels of blood glucose, insulin and gastrin. The mean value of Tmax were 52.0, 77.3 and 85.6 min. Compared to liquid meal, gastric emptying for gelatinized meals was significantly delayed. The mean value of AUC-Tmax were 22.7, 28.7 and 33.7%dose, respectively, and no significant differences in absorption were seen. No significant differences existed in blood glucose, gastrin and insulin. Gelatinization of liquid meal delays gastric emptying. Gelatinized liquid meal may be useful for the management of diarrhea accompanied with enteral nutrition without influencing gastrointestinal hormone and blood glucose.

  18. Wet method for measuring starch gelatinization temperature using electrical conductivity.

    Science.gov (United States)

    Morales-Sanchez, E; Figueroa, J D C; Gaytan-Martínez, M

    2009-09-01

    The objective of the present study was to develop a method for obtaining the gelatinization temperature of starches by using electrical conductivity. Native starches from corn, rice, potato, and wheat were prepared with different proportions of water and heated from room temperature to 90 degrees C, in a device especially designed for monitoring the electrical conductivity as a function of temperature. The results showed a linear trend of the electrical conductivity with the temperature until it reaches the onset gelatinization temperature. After that point, the electrical conductivity presented an increment or decrement depending on the water content in the sample and it was related to starch swelling and gelatinization phenomena. At the end gelatinization temperature, the conductivity becomes stable and linear, indicating that there are no more changes of phase. The starch gelatinization parameter, which was evaluated in the 4 types of starches using the electrical conductivity, was compared with those obtained by using differential scanning calorimeter (DSC). The onset temperature at which the electrical conductivity increased or decreased was found to be similar to that obtained by DSC. Also, the final temperature at which the electrical conductivity returned to linearity matched the end gelatinization temperature of the DSC. Further, a wet method for measuring the onset, peak, and end gelatinization temperatures as a function of temperature using the electrical conductivity curves is presented for a starch-water suspension.

  19. Maintenance of human embryonic stem cells on gelatin

    Institute of Scientific and Technical Information of China (English)

    LI Yang; LIN ChangSheng; WANG Li; LIU Ying; MU XiaoNing; MAYue; LI LingSong

    2009-01-01

    Matrigel is routinely used as a coating material in the feeder-free culture system of human embryonic stem cells (hESCs).However,matrigel is costive and inconvenient to use.In this study,the possibility of using gelatin as an alternative coating material was investigated.The results showed that,after trypsinization,hESCs were maintained undifferentiated on gelatin.These hESCs expressed pluripotent markers,formed teratoma and maintained a normal karyotype.As measured at passage 10,the hESCs expressed a high level of Oct4 on both gelatin and Matrigel.hESCs growing on gelatin formed AP-positive colonies in similar size and number to those growing on Matrigel (P>0.05).Moreover,hESCs growing on gelatin contained a comparable percentage of SSEA-4-positive cells to those growing on Matrigel (95.1% vs.94.3%,P>0.05).H-1 hESCs were maintained undifferentiated on gelatin for 20 passages and remained the stable normal karyotype.This gelatin-based culture protocol may allow us to propagate hESCs in large scale,with less cost.

  20. Antioxidant activity of hydrolysates of deer bone gelatin in a liposome

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yuhong; GAO Tian; ZHANG Ligang

    2007-01-01

    Gelatin extracted from deer bone was hydrolyzed for 3.5-120 min. The degree of hydrolysis was higher from Alcalase-hydrolyzed gelatin than that from neutral proteinase-hydrolyzed gelatin. Alcalase-hydrolyzed gelatin exhibited a stronger antioxidant activity than that of neutral proteinase-hydrolyzed gelatin. Hydrolysates showed strong radical-scavenging ability and Fe2+-chelating activity, both of which were influenced by hydrolysis time. Although nonhydrolyzed gelatin displayed a certain antioxidative effect, it was far less than that of hydrolysates. The hydrolysates of deer bone gelatin can work as a radical stabilizer and metal ion chelator to inhibit lipid oxidation.

  1. Comparison of recovered carp scales (Cyprinus carpio gelatin and commercial calf and pork skin gelatins

    Directory of Open Access Journals (Sweden)

    Mehmet Tolga Dinçer

    2016-11-01

    Full Text Available Significant progress carries some evaluations towards the developments on seafood processing technologies and waste utilizing sector in recent years. Evaluation of wastes also has the potential to provide raw material for many industrial sectors. Evaluating the wastes also has a real potential for many industry sectors to obtain raw materials. The development of new products and commercially important of bio-molecules which have to be obtained from the wastes were important area for researches. Gelatin is used as a raw material for food industry and other industries, not only in our country but also in the world. Because of the growing demand particularly in Muslim countries hesitant considering alternatives to pork and calf sourced products are required. In the current study collagen which is used as raw material for many industries was recovered from carp scales (Cyprinus carpio. Obtained collagen was also used to produce gelatin product and some physical (colour, odour and some functional (gelling temperature, viscosity, gel strength properties were compared with commercial calf and pork skin gelatins.

  2. Studies on the starch-water interactions between partially gelatinized corn starch and water during gelatinization.

    Science.gov (United States)

    Fu, Zong-Qiang; Wang, Li-Jun; Zou, Hui; Li, Dong; Adhikari, Benu

    2014-01-30

    The effect of moisture content on the interactions between water and partially gelatinized starch during gelatinization process was investigated. The interactions were probed using differential scanning calorimetry (DSC). The starch samples were partially gelatinized at 25°C (S25), 64°C (S64), 68°C (S68) and 70°C (S70) and the moisture contents were varied from 25% to 78% (w/w). The G endotherm was not observed and only the M1 endotherm was observed in S64, S68 and S70 in the entire moisture content range. The G endotherm was not observed and only the M1 endotherm was observed at higher peak temperature in S25 when the moisture content was below 30% (w/w). The melting temperature of M2 endotherm in S70 was the highest among all the samples tested in the entire moisture content range. At water content>30% (w/w), S68 and S70 had lower amount of unfreezable water, while S64 had higher amount of unfreezable water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Gelatin Effects on the Physicochemical and Hemocompatible Properties of Gelatin/PAAm/Laponite Nanocomposite Hydrogels.

    Science.gov (United States)

    Li, Changpeng; Mu, Changdao; Lin, Wei; Ngai, To

    2015-08-26

    In recent years, inorganic nanoparticles such as Laponite have frequently been incorporated into polymer matrixes to obtain nanocomposite hydrogels with hierarchical structures, ultrastrong tensibilities, and high transparencies. Despite their unique physical and chemical properties, only a few reports have evaluated Laponite-based nanocomposite hydrogels for biomedical applications. This article presents the synthesis and characterization of a novel, hemocompatible nanocomposite hydrogels by in situ polymerization of acrylamide (AAm) in a mixed suspension containing Laponite and gelatin. The compatibility, structure, thermal stability, and mechanical properties of the resulting NC gels with varied gel compositions were investigated. Our results show that the prepared nanocomposite hydrogels exhibit good thermal stability and mechanical properties. The introduction of a biocompatible polymer, gelatin, into the polymer matrix did not change the transparency and homogeneity of the resulting nanocomposite hydrogels, but it significantly decreased the hydrogel's pH-responsive properties. More importantly, gelatins that were incorporated into the PAAm network resisted nonspecific protein adsorption, improved the degree of hemolysis, and eventually prolonged the clotting time, indicating that the in vitro hemocompatibility of the resulting nanocomposite hydrogels had been substantially enhanced. Therefore, these nanocomposite hydrogels provide opportunities for potential use in various biomedical applications.

  4. Gelatin/graphene systems for low cost energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Landi, Giovanni [Faculty of Mathematics and Computer Science, FernUniversität Hagen, 58084 Hagen (Germany); Fedi, Filippo; Sorrentino, Andrea; Iannace, Salvatore [Institute for Composite and Biomedical Materials (IMCB-CNR), Piazzale Enrico Fermi 1, 80055 Portici (Italy); Neitzert, Heinz C. [Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (Italy)

    2014-05-15

    In this work, we introduce the possibility to use a low cost, biodegradable material for temporary energy storage devices. Here, we report the use of biologically derived organic electrodes composed of gelatin ad graphene. The graphene was obtained by mild sonication in a mixture of volatile solvents of natural graphite flakes and subsequent centrifugation. The presence of exfoliated graphene sheets was detected by atomic force microscopy (AFM) and Raman spectroscopy. The homogeneous dispersion in gelatin demonstrates a good compatibility between the gelatin molecules and the graphene particles. The electrical characterization of the resulting nanocomposites suggests the possible applications as materials for transient, low cost energy storage device.

  5. The characterisation of a genipin-gelatin gel dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Davies, J B; Bosi, S; Baldock, C, E-mail: jbd@ansto.gov.a

    2010-11-01

    Genipin cross links gelatin to slowly form a blue colour that bleaches upon irradiation. Spectrophotometric measurements of the absorbance change following irradiation to doses up to 100 Gy gives a linear dose response for certain concentrations of the gel ingredients; genipin, gelatin and sulphuric acid. Dose sensitivity increases with increasing concentrations of sulphuric acid and genipin and is also strongly dependent on the time allowed for the genipin-gelatin cross linking reaction (referred to here as blending) to take place. The optimum formulation of this gel was found for genipin concentration between 0.3 - 0.5 mM and blending time of at least 4 h.

  6. Gelatin/piassava composites treated by Electron Beam Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Takinami, Patricia Yoko Inamura; Shimazaki, Kleber; Moura, Esperidiana Augusta Barretos de; Mastro, Nelida Lucia del, E-mail: patyoko@yahoo.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Colombo, Maria Aparecida [Faculdade de Tecnologia da Zona Leste (FATEC), Sao Paulo, SP (Brazil)

    2010-07-01

    Piassava (Attalea funifera Mart) fiber has been investigated as reinforcement for polymer composites with potential for practical applications. The purpose of the present work was to assess the behavior of specimens of piassava fiber and gelatin irradiated with electron beam at different doses and percentage. The piassava/gelatin specimens were made with 5 and 10% (w/w) piassava fiber, gelatin 25% (w/w), glycerin as plasticizer and acrylamide as copolymer. The samples were irradiated up to 40 kGy using an electron beam accelerator, at room temperature in presence of air. Preliminary results showed mechanical properties enhancement with the increase in radiation dose. (author)

  7. Rheological properties of gelatin, carrageenan and locust bean gum mixtures

    OpenAIRE

    Jones, Guy Matthew John

    2004-01-01

    This thesis reports data on blends of carrageenan (0.3%w/w) and locust bean gum (0.3%w/w) in the presence of biopolymers, particularly gelatin of varying concentration. Particular attention is given to their behaviour on autoclaving since this is relevant to one of the most important applications of these materials as gelling agents in canned meat products. It was shown there is such 3% gelatin could be found in the gelling system as a result of from collagen in the meat. Gelatin at this ...

  8. Gelation on heating of supercooled gelatin solutions.

    Science.gov (United States)

    Guigo, Nathanaël; Sbirrazzuoli, Nicolas; Vyazovkin, Sergey

    2012-04-23

    Diluted (1.0-1.5 wt%) aqueous gelatin solutions have been cooled to -10 °C at a cooling rate 20 °C min(-1) without freezing and detectable gelation. When heated at a constant heating rate (0.5 -2 °C min(-1)), the obtained supercooled solutions demonstrate an atypical process of gelation that has been characterized by regular and stochastically modulated differential scanning calorimetry (DSC) as well as by isoconversional kinetic analysis. The process is detectable as an exothermic peak in the total heat flow of regular DSC and in the nonreversing heat flow of stochastically modulated DSC. Isoconversional kinetic analysis applied to DSC data reveals that the effective activation energy of the process increases from approximately 75 to 200 kJ mol(-1) as a supercooled solution transforms to gel on continuous heating.

  9. Solvent effects on starch dissolution and gelatinization.

    Science.gov (United States)

    Koganti, Nagamani; Mitchell, John R; Ibbett, Roger N; Foster, Tim J

    2011-08-08

    The disruption of starch granular structure during dissolution in varying concentrations of N-methyl morpholine N-oxide (NMMO) has been studied using three maize starches with varying ratios of amylose and amylopectin. Behavior in NMMO has been characterized by differential scanning calorimetry (DSC), microscopy, rapid viscosity analysis (RVA), and rheometry. Exothermic transitions were observed for the three starches in both 78 and 70% NMMO; the transition changed to an endotherm at 60 and 50% NMMO. Consistent with DSC, hot stage microscopy showed that starch granules dissolved at NMMO concentrations of 78 and 70%, whereas in 60 and 50% NMMO, gelatinization behavior similar to that found for starch in water was observed. Mechanical spectroscopy revealed the dominant viscous behavior (G″ > G') of starch at NMMO concentrations of 70 and 78% and more elastic behavior (G' > G″) at lower concentrations. Starch solutions in 78% NMMO obey the Cox-Merz rule, suggesting that the solutions are homogeneous on a molecular level.

  10. Changes on the corneal thickness and curvature after orthokeratology

    Science.gov (United States)

    Mitsui, Iwane; Yamada, Yoshiya

    2004-07-01

    To evaluate the corneal thickness and curvature changes after Orthokeratology contact lens wear, using the ORBSCAN II corneal topography system, corneal thickness and corneal curvature were measured on one hundred and twenty eyes of sixty patients before and after wearing the custom rigid gas permeable contact lenses for Orthokeratology. The contact lenses were specially designed for each eye. The subjects wore the orthokeratology lenses for approximately Four hours with their eyes closed. The corneal thickness of the subjects was increased on fifty-five eyes at not only the peripheral zone but also the center of the cornea. The average increase of central and peripheral corneal thickness was 18 micrometer and 22micrometer, respectively. The mean anterior curvature of corneal surface changed 1.25D. The mean posterior curvature of corneal endothelium side changed 0.75D.

  11. Acute Corneal Hydrops 3 Years after Intra-corneal Ring Segments and Corneal Collagen Cross-linking

    Science.gov (United States)

    Antonios, Rafic; Dirani, Ali; Fadlallah, Ali; Chelala, Elias; Hamadeh, Adib; Jarade, Elias

    2016-01-01

    This case report describes a 15-year-old male with allergic conjunctivitis and keratoconus, who underwent uneventful intra-corneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in the right eye. During the follow-up periods, the patient was noted to have several episodes of allergic conjunctivitis that were treated accordingly. At the 2 years postoperatively, he presented with another episode of allergic conjunctivitis and progression of keratoconus was suspected on topography. However, the patient was lost to follow-up, until he presented with acute hydrops at 3 years postoperatively. There are no reported cases of acute corneal hydrops in cross-linked corneas. We suspect the young age, allergic conjunctivitis and eye rubbing may be a risk factors associated with possible progression of keratoconus after CXL. Prolonged follow-up and aggressive control of the allergy might be necessary in similar cases. PMID:26957859

  12. [Representation and mathematical analysis of human corneal surface].

    Science.gov (United States)

    Tălu, Stefan; Tălu, Mihai; Giovanzana, Stefano

    2011-01-01

    In the description and analysis of human corneal surface are used various mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the cornea. Mathematical models are important into the biomechanics of the cornea to model the corneal behavior. Corneal biomechanics also has the potential to improve outcomes in refractive surgery. The objective of this paper is to present the most representative mathematical models currently used for modeling of human corneal in optics and biomechanics fields.

  13. The molecular genetics of the corneal dystrophies--current status.

    Science.gov (United States)

    Klintworth, Gordon K

    2003-05-01

    The pertinent literature on inherited corneal diseases is reviewed in terms of the chromosomal localization and identification of the responsible genes. Disorders affecting the cornea have been mapped to human chromosome 1 (central crystalline corneal dystrophy, familial subepithelial corneal amyloidosis, early onset Fuchs dystrophy, posterior polymorphous corneal dystrophy), chromosome 4 (Bietti marginal crystalline dystrophy), chromosome 5 (lattice dystrophy types 1 and IIIA, granular corneal dystrophy types 1, 2 and 3, Thiel-Behnke corneal dystrophy), chromosome 9 (lattice dystrophy type II), chromosome 10 (Thiel-Behnke corneal dystrophy), chromosome 12 (Meesmann dystrophy), chromosome 16 (macular corneal dystrophy, fish eye disease, LCAT disease, tyrosinemia type II), chromosome 17 (Meesmann dystrophy, Stocker-Holt dystrophy), chromosome 20 (congenital hereditary endothelial corneal dystrophy types I and II, posterior polymorphous corneal dystrophy), chromosome 21 (autosomal dominant keratoconus) and the X chromosome (cornea verticillata, cornea farinata, deep filiform corneal dystrophy, keratosis follicularis spinulosa decalvans, Lisch corneal dystrophy). Mutations in nine genes (ARSC1, CHST6, COL8A2, GLA, GSN, KRT3, KRT12, M1S1and TGFBI [BIGH3]) account for some of the corneal diseases and three of them are associated with amyloid deposition in the cornea (GSN, M1S1, TGFBI) including most of the lattice corneal dystrophies (LCDs) [LCD types I, IA, II, IIIA, IIIB, IV, V, VI and VII] recognized by their lattice pattern of linear opacities. Genetic studies on inherited diseases affecting the cornea have provided insight into some of these disorders at a basic molecular level and it has become recognized that distinct clinicopathologic phenotypes can result from specific mutations in a particular gene, as well as some different mutations in the same gene. A molecular genetic understanding of inherited corneal diseases is leading to a better appreciation of the

  14. Contact lens rehabilitation following repaired corneal perforations

    Directory of Open Access Journals (Sweden)

    Sreenivas V

    2006-03-01

    Full Text Available Abstract Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60% required aphakic contact lenses. The best corrected visual acuity (BCVA of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25% eyes with spectacle correction and 37 (92.5% eyes with the use of contact lens (p Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries.

  15. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

    Directory of Open Access Journals (Sweden)

    Winai Chaidaroon

    2016-07-01

    Full Text Available Purpose: To report a rare case of keratitis infected by Bipolaris hawaiiensis. Methods: A patient who was diagnosed as fungal keratitis caused by B. hawaiiensis was retrospectively reviewed for history, clinical characteristics, risk factors, laboratory findings, treatments, and outcomes. Results: A 63-year-old man with a history of trauma and saw dust in the left eye presented with a corneal ulcer. Eye examination revealed whitish infiltration with a feathery edge and small brownish deposits in the anterior stroma of the left cornea. Numerous septate hyphal fragments were detected in a corneal specimen, and nucleotide sequence analysis identified B. hawaiiensis. Treatment was started with 5% natamycin eyedrops and oral itraconazole. Subsequently, a corneal plaque developed which did not respond to medication and debridement. The patient underwent therapeutic penetrating keratoplasty. Conclusions: B. hawaiiensis is a rare cause of corneal phaeohyphomycosis. A brownish pigmented infiltration is an important diagnostic clue, however microbiologic studies are required to obtain a definite diagnosis. Although antifungal medication and debridement are the mainstay of most corneal fungal infection, therapeutic penetrating keratoplasty can prevent morbidity related to this fungal infection.

  16. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

    Science.gov (United States)

    Chaidaroon, Winai; Supalaset, Sumet; Tananuvat, Napaporn; Vanittanakom, Nongnuch

    2016-01-01

    Purpose To report a rare case of keratitis infected by Bipolaris hawaiiensis. Methods A patient who was diagnosed as fungal keratitis caused by B. hawaiiensis was retrospectively reviewed for history, clinical characteristics, risk factors, laboratory findings, treatments, and outcomes. Results A 63-year-old man with a history of trauma and saw dust in the left eye presented with a corneal ulcer. Eye examination revealed whitish infiltration with a feathery edge and small brownish deposits in the anterior stroma of the left cornea. Numerous septate hyphal fragments were detected in a corneal specimen, and nucleotide sequence analysis identified B. hawaiiensis. Treatment was started with 5% natamycin eyedrops and oral itraconazole. Subsequently, a corneal plaque developed which did not respond to medication and debridement. The patient underwent therapeutic penetrating keratoplasty. Conclusions B. hawaiiensis is a rare cause of corneal phaeohyphomycosis. A brownish pigmented infiltration is an important diagnostic clue, however microbiologic studies are required to obtain a definite diagnosis. Although antifungal medication and debridement are the mainstay of most corneal fungal infection, therapeutic penetrating keratoplasty can prevent morbidity related to this fungal infection. PMID:27721785

  17. Corneal trephination with the femtosecond laser.

    Science.gov (United States)

    Meltendorf, Christian; Schroeter, Jan; Bug, Reinhold; Kohnen, Thomas; Deller, Thomas

    2006-10-01

    To evaluate the feasibility and cut quality of corneal trephination in human donor corneal tissue with the femtosecond laser. Twelve human corneoscleral discs were inserted in an artificial anterior chamber. After corneal thickness measurement and tonometry, the cornea was mounted on a femtosecond laser (FEMTEC; 20/10 Perfect Vision, Heidelberg, Germany) through a contact lens (patient interface). Trephination was performed with diameters of 7.0, 7.5, 8.0, and 8.5 mm in 3 corneas each. The corneal button was removed from the corneoscleral disc in 2 of the 3 corneas in each case. The cut was not manipulated in the remaining corneas to enable histologic detection of possible tissue bridges. The cut edges were macroscopically and light-microscopically examined for quality. Corneal buttons and corneoscleral discs could be separated by blunt dissection in all cases. Tissue bridges were more common in thicker edematous corneas than in thinner ones. Both the macro- and microscopic examination disclosed smooth rectilinear cut margins with a perpendicular cut edge. This feasibility study shows that the femtosecond laser enables sufficient trephination of human donor corneas.

  18. Corneal reconstruction by stem cells and bioengineering

    Directory of Open Access Journals (Sweden)

    Arjamaa O

    2012-09-01

    Full Text Available Olli ArjamaaDepartment of Biology, University of Turku, Turku, FinlandAbstract: Almost 300 million people are visually impaired worldwide due to various eye diseases such as cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy, and corneal diseases. Notably, ten million people are blind because of severe ocular surface diseases and the majority of cases occur in developing countries. Blinding ocular surface diseases have, however, become treatable by grafting of surface layers, or by full-thickness transplantation of the cornea. As the demand for human corneal tissue for surface reconstruction and transplantation far exceeds the supply, methods are being developed to supplement tissue donation. Xenotransplantation of the cornea or cells from genetically modified pigs may become one of the solutions. Transplantation of limbal stem cells within tissue biopsies, to restore the transparency of the cornea is another remarkable method, which has shown its potential in several clinical studies. The combination of stem cell technology and engineering of biocompatible tissue equivalent, still at preclinical stage, has shown us how synthetic corneal tissue is able to guide cultured corneal stromal stem cells of human origin, to become native-like stroma, the most important layer of the cornea. These findings give hope for a large-quantity production of biomaterial for corneal reconstruction. As such, clinical ophthalmologists should become more familiar with the methods of laboratory science.Keywords: eye, grafting, keratoplasty, xenotransplantation, cell reservoir, biocompatible tissue equivalent

  19. IgE-mediated allergic reactions to fruit gums and investigation of cross-reactivity between gelatine and modified gelatine-containing products.

    Science.gov (United States)

    Wahl, R; Kleinhans, D

    1989-01-01

    A 32-year-old female reacted with a contact urticaria syndrome after eating 'gummy bears' (fruit gums). The reaction began in the oral mucosa and led to treatment on an inpatient basis. RAST measurements with allergen discs produced with gelatine and gelatine-containing products (among them 'gummy bears') demonstrated the presence of IgE antibodies in the serum of this patient. Proteins with molecular weights in the range of 40-120 kD were identified as the allergens in gelatine by using Western blot analysis. RAST inhibition showed cross-reactivity between gelatine, gelatine-containing products and the modified gelatine used in some plasma substitutes. Allergic reactions towards coloured fruit candies and 'gummy bears' may result from an IgE-mediated hypersensitivity towards gelatine. The long-known anaphylactoid reactions towards gelatine-containing plasma substitutes may, at least in part, be of an allergic nature.

  20. Analysis of the horizontal corneal diameter, central corneal thickness, and axial length in premature infants

    Directory of Open Access Journals (Sweden)

    Ozdemir Ozdemir

    2014-08-01

    Full Text Available Purpose: To determine the horizontal corneal diameter, central corneal thickness, and axial length in premature infants. Methods: Infants with a birth weight of less than 2,500 g or with a gestation period of less than 36 weeks were included in the study. Infants with retinopathy of prematurity (ROP were allocated to Group 1 (n=138, while those without ROP were allocated to Group 2 (n=236. All infants underwent a complete ophthalmologic examination, including corneal diameter measurements, pachymetry, biometry, and fundoscopy. Between-group comparisons of horizontal corneal diameter, central corneal thickness, and axial lengths were performed. Independent sample t-tests were used for statistical analysis. Results: Data was obtained from 374 eyes of 187 infants (102 female, 85 male. The mean gestational age at birth was 30.7 ± 2.7 weeks (range 25-36 weeks, the mean birth weight was 1,514 ± 533.3 g (range 750-1,970 g, and the mean postmenstrual age at examination was 40.0 ± 4.8 weeks. The mean gestational age and the mean birth weight of Group 1 were statistically lower than Group 2 (p0.05. Conclusions: The presence of ROP in premature infants does not alter the horizontal corneal diameter, central corneal thickness, or axial length.

  1. 21 CFR 886.1450 - Corneal radius measuring device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  2. Starvation marrow – gelatinous transformation of bone marrow

    Directory of Open Access Journals (Sweden)

    Eric Osgood

    2014-09-01

    Full Text Available Gelatinous bone marrow transformation (GMT, also known as starvation marrow, represents a rare pathological entity of unclear etiology, in which bone marrow histopathology demonstrates hypoplasia, fat atrophy, and gelatinous infiltration. The finding of gelatinous marrow transformation lacks disease specificity; rather, it is an indicator of severe illness and a marker of poor nutritional status, found in patients with eating disorders, acute febrile illnesses, acquired immunodeficiency syndrome, alcoholism, malignancies, and congestive heart failure. We present a middle-aged woman with a history of alcoholism, depression, and anorexia nervosa who presented with failure to thrive and macrocytic anemia, with bone marrow examination demonstrative of gelatinous transformation, all of which resolved with appropriate treatment. To our knowledge, there are very few cases of GMT which have been successfully treated; thus, our case highlights the importance of proper supportive management.

  3. Possible influences on bullet trajectory deflection in ballistic gelatine.

    Science.gov (United States)

    Riva, Fabiano; Kerkhoff, Wim; Bolck, Annabel; Mattijssen, Erwin J A T

    2017-02-01

    The influence of the distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots on a bullet's trajectory, when passing through ballistic gelatine, was studied. No significant difference in deflection was found when trajectories of 9mm Luger bullets, fired at a 3.5cm distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots, were compared to trajectories of bullets fired 7cm or more away from any of the aforementioned aspects. A surprisingly consistent 6.5° absolute deflection angle was found when these bullets passed through 22.5 to 23.5cm of ballistic gelatine. The projection angle, determined by the direction of the deflection, appeared to be random. The consistent absolute angle, in combination with the random projection angle, resulted in a cone-like deflection pattern.

  4. Release of lysozyme from electrospun PVA/lysozyme-gelatin scaffolds

    Institute of Scientific and Technical Information of China (English)

    Dong-zhi YANG; Yu-hua LONG; Jun NIE

    2008-01-01

    This article describes an electrospinning process in fabricating ultra fine fibers with core-shell structure. A biodegradable polymer, poly(vinyl alcohol) (PVA), was used as the shell; lysozyme was a kind of antioxidant; and gelatin were used as the core. Morphology and microstruc-ture of the ultra fine fibers were characterized by scanning electron microscope (SEM), transmission electron micro-scopy (TEM) and X-ray photoelectron spectroscopy (XPS) analysis. As a comparison, composite nanofiber PVA/lysozyme-gelatin blend was prepared by a normal electrospinning process. In vitro drug release behaviors of the nanofibrous membranes were determined in phosphate-buffered saline (PBS) solution. It was found that core-shell nanofibers PVA/lysozyme-gelatin obviously exhibit higher initial release rates compared to that of PVA/lysozyme-gelatin blend nanofibers. The current method may find wide application in controlled release of bioactive proteins and tissue engineering.

  5. Marine ecology: gelatinous bells may ring change in marine ecosystems.

    Science.gov (United States)

    Hay, Steve

    2006-09-05

    Gelatinous plankton are critical components of marine ecosystems. Recent studies are providing evidence of increased population outbursts of such species. Jellyfish seem to respond when an ecosystem is over-fished, and their ecology is under-researched.

  6. Dichromated-gelatin hologram process for improved optical quality

    Science.gov (United States)

    Stewart, W. C.

    1975-01-01

    Optical distortions are eliminated by use of wetting agency followed by sequential immersion in several alcohol-water baths of increasing alcohol concentration. Dehydration proceeds uniformly over surface of gelatin. Dried plate is free of optically-distorting thickness variations.

  7. Discussion on the Gelatin%浅谈明胶

    Institute of Scientific and Technical Information of China (English)

    郭玮

    2012-01-01

    Gelatin is a partially hydrolyzed product of the collagen.Most gelatins are extracted from animal tissues,such as skins and bones,etc.Gelatin has wide applications in food,pharmaceutical,photographic,and industrial areas.This paper focuses on the source and composition of gelatin,classification and application,and potential dangers.%明胶是胶原蛋白部分水解的产物,是从动物的皮、骨等结蹄组织中提取而成,在食品、医药、感光和工业等领域有着广泛的用途。文章就明胶的来源和组成、分类和应用以及潜在的危害性等方面进行综述,使人们能对明胶有个基本的认识。

  8. Preparation and Characterization Analysis of Hydroxyapatite/Gelatin Composite

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The hydroxyapatite (HAp)/gelatin composite was prepared by self-assembly method. X-ray diffraction confirmed that the inorganic phase in the composite was HAp. The Fourier transform infra-red spectrum(FT-IR) indicated the presence of amide and hydroxyl groups in the composite. The organic-inorganic ratio of the composite is similar to that of the human bone, which was determined by differential thermal analysis ( DTA )and thermogravimetric analysis ( TGA ). Transmission Electron Microscopy (TEM) showed that the composite is composed by spindly grains and the multilayer nanostructure can also be seen. Gelatin in the composite assembled orderly and directionally ; and the HAp crystals grew along the gelatin molecule at nearly the same direction. A model was established to explain the process of the interaction between gelatin and HAp.

  9. Preparation and characterization of gelatin scaffold containing microorganism fermented cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Mook; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang; Lee, Byeong Heon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Mi Yeong; Lee, Jong Dae; Song, Sung Gi [Quegenbiotech, Co., Incheon (Korea, Republic of)

    2010-12-15

    Cellulose, chitin, chitosan and hyaluronic acid are well known as polysaccharides. These polysaccharides have many effects on cell growth and differentiation. Cell activation increases with increasing the polysaccharides concentration. In this study, gelatin scaffold containing microorganism fermented cellulose, citrus gel were prepared by using irradiation technique. Physical properties of the scaffolds were investigated as a function of the concentrations of gelatin and citrus gel and the cell attachment, cell morphology and inflammation of the scaffolds also were characterized for regeneration of skin tissue.

  10. Synthesis and characterization of gelatin based polyester urethane scaffold

    Indian Academy of Sciences (India)

    S Sarkar; A Chourasia; S Maji; S Sadhukhan; S Kumar; B Adhikari

    2006-10-01

    For tissue engineering purpose two gelatin based polyester urethane scaffolds of different compositions were prepared from lactic acid, polyethylene glycol 400 (PEG 400) and characterized by FTIR, XRD for their mechanical and morphological properties using SEM and optical microscopic analyses. Degradation and swelling studies of gelatin based polyester urethane scaffolds in phosphate buffer saline (PBS) were performed. Human keratinocyte cells were cultured within these scaffolds, which showed good cell adherence and proliferation.

  11. Soft Collagen-Gelatine Sponges by Convection Drying

    Directory of Open Access Journals (Sweden)

    Michael Meyer

    2015-02-01

    Full Text Available This study showed that thermally labile fibrillar collagen could be processed continuously in combination with gelatine as foaming additive by convection drying. The procedure led to stable sponges with similar structural and physical properties as found for freeze-dried collagen samples. The fibrillar collagen remained native, while gelatine acted as foaming additive. The absorbency of the sponges was improved by opening the surface with abrasives. A use as medical device with hemostyptic properties would be possible.

  12. Enzymatic regulation of functional vascular networks using gelatin hydrogels.

    Science.gov (United States)

    Chuang, Chia-Hui; Lin, Ruei-Zeng; Tien, Han-Wen; Chu, Ya-Chun; Li, Yen-Cheng; Melero-Martin, Juan M; Chen, Ying-Chieh

    2015-06-01

    To manufacture tissue engineering-based functional tissues, scaffold materials that can be sufficiently vascularized to mimic the functionality and complexity of native tissues are needed. Currently, vascular network bioengineering is largely carried out using natural hydrogels as embedding scaffolds, but most natural hydrogels have poor mechanical stability and durability, factors that critically limit their widespread use. In this study, we examined the suitability of gelatin-phenolic hydroxyl (gelatin-Ph) hydrogels that can be enzymatically crosslinked, allowing tuning of the storage modulus and the proteolytic degradation rate, for use as injectable hydrogels to support the human progenitor cell-based formation of a stable and mature vascular network. Porcine gelatin-Ph hydrogels were found to be cytocompatible with human blood-derived endothelial colony-forming cells and white adipose tissue-derived mesenchymal stem cells, resulting in >87% viability, and cell proliferation and spreading could be modulated by using hydrogels with different proteolytic degradability and stiffness. In addition, gelatin was extracted from mouse dermis and murine gelatin-Ph hydrogels were prepared. Importantly, implantation of human cell-laden porcine or murine gelatin-Ph hydrogels into immunodeficient mice resulted in the rapid formation of functional anastomoses between the bioengineered human vascular network and the mouse vasculature. Furthermore, the degree of enzymatic crosslinking of the gelatin-Ph hydrogels could be used to modulate cell behavior and the extent of vascular network formation in vivo. Our report details a technique for the synthesis of gelatin-Ph hydrogels from allogeneic or xenogeneic dermal skin and suggests that these hydrogels can be used for biomedical applications that require the formation of microvascular networks, including the development of complex engineered tissues.

  13. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Changcan; Yuan, Wenjie; Khan, Musammir; Li, Qian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin) Tianjin 300072 (China); Yao, Fanglian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Zhang, Wencheng, E-mail: wenchengzhang@yahoo.com [Department of Physiology and Pathophysiology, Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China)

    2015-05-01

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  14. Differences in cytocompatibility between collagen, gelatin and keratin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yanfang; Zhang, Weiwei; Yuan, Jiang, E-mail: jyuan@njnu.edu.cn; Shen, Jian, E-mail: jshen@njnu.edu.cn

    2016-02-01

    Keratins are cysteine-rich intermediate filament proteins found in the cytoskeleton of the epithelial cells and in the matrix of hair, feathers, wool, nails and horns. The natural abundance of cell adhesion sequences, RGD (Arg-Gly-Asp) and LDV (Leu-Asp-Val), makes them suitable for tissue engineering applications. The purpose of our study is to evaluate their cytocompatibility as compared to well-known collagen and gelatin proteins. Herein, collagen, gelatin and keratin were blended with poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and electrospun to afford nanofibrous mats, respectively. These PHBV/protein composite mats were characterized by field emission scanning electron microscopy (FE-SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and dynamic mechanical analysis (DMA). The cytocompatibility was evaluated with cell adhesion, cell viability and cell proliferation. The data from MTT and BrDU revealed that collagen had significantly superior cytocompatibility as compared to gelatin and keratin. Gelatin showed a better cytocompatibility than keratin without statistical significance difference. Finally, we gave the reasons to account for the above conclusions. - Highlights: • Collagen, gelatin and keratin were coelectrospun with PHBV to afford nanofibrous mats. • Cytocompatibility was evaluated with cell adhesion, cell viability and cell proliferation. • Collagen had significantly superior cytocompatibility as compared to gelatin and keratin.

  15. Gelatin-Based Hydrogels for Organ 3D Bioprinting

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2017-08-01

    Full Text Available Three-dimensional (3D bioprinting is a family of enabling technologies that can be used to manufacture human organs with predefined hierarchical structures, material constituents and physiological functions. The main objective of these technologies is to produce high-throughput and/or customized organ substitutes (or bioartificial organs with heterogeneous cell types or stem cells along with other biomaterials that are able to repair, replace or restore the defect/failure counterparts. Gelatin-based hydrogels, such as gelatin/fibrinogen, gelatin/hyaluronan and gelatin/alginate/fibrinogen, have unique features in organ 3D bioprinting technologies. This article is an overview of the intrinsic/extrinsic properties of the gelatin-based hydrogels in organ 3D bioprinting areas with advanced technologies, theories and principles. The state of the art of the physical/chemical crosslinking methods of the gelatin-based hydrogels being used to overcome the weak mechanical properties is highlighted. A multicellular model made from adipose-derived stem cell proliferation and differentiation in the predefined 3D constructs is emphasized. Multi-nozzle extrusion-based organ 3D bioprinting technologies have the distinguished potential to eventually manufacture implantable bioartificial organs for purposes such as customized organ restoration, high-throughput drug screening and metabolic syndrome model establishment.

  16. Preparation and stabilization of heparin/gelatin complex coacervate microcapsules.

    Science.gov (United States)

    Tsung, M; Burgess, D J

    1997-05-01

    The aims of this study are to optimize conditions for the preparation, stabilization, and harvesting of heparin/gelatin microcapsules prepared by complex coacervation. Microelectrophoresis and dry coacervate weight were used to determine the optimum conditions of pH and ionic strength for maximum heparin/gelatin coacervate yield. Heparin/gelatin microcapsules were formed by complex coacervation in the presence and absence of poly(1-vinyl-2-pyrrolidone) (PVP), which was used as a stabilizer. The microcapsules were collected using a spray-drying technique. Microcapsule particle size was analyzed using an AccuSizer optical sizer. Optimized conditions for maximum coacervate yield were pH 2.6, ionic strength 10 mM, and a 1:2 heparin/gelatin A ratio. PVP stabilized the heparin/gelatin coacervate droplets and reduced droplet aggregation during spray-drying. The mean particle diameter of the spray-dried coacervate droplets was lower in the presence of PVP and was unaffected by PVP concentration (in the range 0.5-2.0% w/w). Heparin/gelatin microcapsules, prepared under conditions optimized for maximum coacervate yield, were stabilized without the use of chemical cross-linking agents. Stabilization was achieved by a combination of the addition of PVP and spray-drying.

  17. Microchannel emulsification using gelatin and surfactant-free coacervate microencapsulation.

    Science.gov (United States)

    Nakagawa, Kei; Iwamoto, Satoshi; Nakajima, Mitsutoshi; Shono, Atsushi; Satoh, Kazumi

    2004-10-01

    In this study, we investigated the use of microchannel (MC) emulsifications in producing monodisperse gelatin/acacia complex coacervate microcapsules of soybean oil. This is considered to be a novel method for preparing monodisperse O/W and W/O emulsions. Generally, surfactants are necessary for MC emulsification, but they can also inhibit the coacervation process. In this study, we investigated a surfactant-free system. First, MC emulsification using gelatin was compared with that using decaglycerol monolaurate. The results demonstrated the potential use of gelatin for MC emulsification. MC emulsification experiments conducted over a range of conditions revealed that the pH of the continuous phase should be maintained above the isoelectric point of the gelatin. A high concentration of gelatin was found to inhibit the production of irregular-sized droplets. Low-bloom gelatin was found to be suitable for obtaining monodisperse emulsions. Finally, surfactant-free monodisperse droplets prepared by MC emulsification were microencapsulated with coacervate. The microcapsules produced by this technique were observed with a confocal laser scanning microscope. Average diameters of the inner cores and outer shells were 37.8 and 51.5 microm; their relative standard deviations were 4.9 and 8.4%.

  18. Molecular interactions in gelatin/chitosan composite films.

    Science.gov (United States)

    Qiao, Congde; Ma, Xianguang; Zhang, Jianlong; Yao, Jinshui

    2017-11-15

    Gelatin and chitosan were mixed at different mass ratios in solution forms, and the rheological properties of these film-forming solutions, upon cooling, were studied. The results indicate that the significant interactions between gelatin and chitosan promote the formation of multiple complexes, reflected by an increase in the storage modulus of gelatin solution. Furthermore, these molecular interactions hinder the formation of gelatin networks, consequently decreasing the storage modulus of polymer gels. Both hydrogen bonds and electrostatic interactions are formed between gelatin and chitosan, as evidenced by the shift of the amide-II bands of polymers. X-ray patterns of composite films indicate that the contents of triple helices decrease with increasing chitosan content. Only one glass transition temperature (Tg) was observed in composite films with different composition ratios, and it decreases gradually with an increase in chitosan proportion, indicating that gelatin and chitosan have good miscibility and form a wide range of blends. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Corneal nerve microstructure in Parkinson's disease.

    Science.gov (United States)

    Misra, Stuti L; Kersten, Hannah M; Roxburgh, Richard H; Danesh-Meyer, Helen V; McGhee, Charles N J

    2017-03-03

    Ocular surface changes and blink abnormalities are well-established in Parkinson's disease. Blink rate may be influenced by corneal sub-basal nerve density, however, this relationship has not yet been investigated in Parkinson's disease. This case-control study examined the ocular surface in patients with moderately severe Parkinson's disease, including confocal microscopy of the cornea. Fifteen patients with moderately severe Parkinson's disease (modified Hoehn and Yahr grade 3 or 4) and fifteen control participants were recruited. Ophthalmic assessment included slit-lamp examination, blink rate assessment, central corneal aesthesiometry and in vivo corneal confocal microscopy. The effect of disease laterality was also investigated. Of the 15 patients with Parkinson's disease, ten were male and the mean age was 65.5±8.6years. The corneal sub-basal nerve plexus density was markedly reduced in patients with Parkinson's disease (7.56±2.4mm/mm(2)) compared with controls (15.91±2.6mm/mm(2)) (pParkinson's disease (0.79±1.2mBAR) and the control group (0.26±0.35mBAR), p=0.12. Sub-basal nerve density was not significantly different between the eye ipsilateral to the side of the body with most-severe motor symptoms, and the contralateral eye. There was a significant positive correlation between ACE-R scores and sub-basal corneal nerve density (R(2)=0.66, p=0.02). This is the first study to report a significant reduction in corneal sub-basal nerve density in Parkinson's disease and demonstrate an association with cognitive dysfunction. These results provide further evidence to support the involvement of the peripheral nervous system in Parkinson's disease, previously thought to be a central nervous system disorder.

  20. Normal corneal endothelial cell density in Nigerians

    Directory of Open Access Journals (Sweden)

    Ewete T

    2016-03-01

    Full Text Available Temitope Ewete,1 Efeoghene Uchenna Ani,2 Adegboyega Sunday Alabi1 1MeCure Eye Center, Lagos, 2Department of Ophthalmology, University of Port Harcourt, Port Harcourt, Nigeria Aim: The aim of the study was to describe the corneal endothelial cell density of adults at the MeCure Eye Center and to determine the relationship between age, sex, and corneal endothelial cell density. Methods: This study was a retrospective study looking at those records of individuals who had undergone specular microscopy or corneal endothelial cell count measurement at the MeCure Eye Center. Results: The endothelial cell characteristics of 359 healthy eyes of 201 volunteers were studied. The mean corneal endothelial cell density (MCD was 2,610.26±371.87 cells/mm2 (range, 1,484–3,571 cells/mm2. The MCD decreased from 2,860.70 cells/mm2 in the 20–30-year age group to 2,493.06 cells/mm2 in the >70-year age group, and there was a statistically significant relationship between age and MCD with a P-value of <0.001. There was no statistically significant correlation between sex and corneal endothelial cell density (P=0.45. Conclusion: This study shows that endothelial cell density in Nigerian eyes is less than that reported in the Japanese, American, and Chinese eyes, and is comparable to that seen in Indian and Malaysian eyes. Keywords: corneal, endothelial cell density, Nigerian

  1. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-10-01

    Full Text Available Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, contact between the stroma and epithelium resulting from Bowman’s membrane rupture, chromatin fragmentation in keratocyte nuclei, phagocytosis, abnormal staining and arrangement of collagen fibers, enzyme system disorders, and keratocyte apoptosis. In corneal ectasia, altered enzymatic processes result in the synthesis of abnormal collagen. Collagen packing is determined by the activity of various extracellular matrix enzymes which bind amines and aldehydes of collagen fiber amino acids. In the late stage, morphological changes of Descemet’s membrane (i.e., rupture and detachment develop. Abnormal hexagonal-shaped keratocytes and their apoptosis are the signs of endothelial dystrophy. The lack of analogs in domestic ophthalmology encouraged the scientists of Ufa Eye Research Institute to develop a device for corneal collagen crosslinking. The parameters of ultraviolet (i.e., wavelength, exposure time, power to achieve the desired effect were identified. The specifics of some photosensitizers in the course of the procedure were studied. UFalink, a device for UV irradiation of cornea, and photosensitizer Dextralink were developed and adopted. Due to the high risk of endothelial damage, this treatment is contraindicated in severe keratoconus (CCT less than 400 microns. Major effects of corneal collagen crosslinking are the following: Young’s modulus (modulus of elasticity increase by 328.9 % (on average, temperature tolerance increase by 5

  2. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-01-01

    Full Text Available Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, contact between the stroma and epithelium resulting from Bowman’s membrane rupture, chromatin fragmentation in keratocyte nuclei, phagocytosis, abnormal staining and arrangement of collagen fibers, enzyme system disorders, and keratocyte apoptosis. In corneal ectasia, altered enzymatic processes result in the synthesis of abnormal collagen. Collagen packing is determined by the activity of various extracellular matrix enzymes which bind amines and aldehydes of collagen fiber amino acids. In the late stage, morphological changes of Descemet’s membrane (i.e., rupture and detachment develop. Abnormal hexagonal-shaped keratocytes and their apoptosis are the signs of endothelial dystrophy. The lack of analogs in domestic ophthalmology encouraged the scientists of Ufa Eye Research Institute to develop a device for corneal collagen crosslinking. The parameters of ultraviolet (i.e., wavelength, exposure time, power to achieve the desired effect were identified. The specifics of some photosensitizers in the course of the procedure were studied. UFalink, a device for UV irradiation of cornea, and photosensitizer Dextralink were developed and adopted. Due to the high risk of endothelial damage, this treatment is contraindicated in severe keratoconus (CCT less than 400 microns. Major effects of corneal collagen crosslinking are the following: Young’s modulus (modulus of elasticity increase by 328.9 % (on average, temperature tolerance increase by 5

  3. Corneal Topographic Analysis in Patients with Cataract

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    We studied the corneal curvature of 161 eyes in 101 patients, aged from 50 to 80 years (mean: 63 years), with senile cataract using the Topographic Modeling System (IMS) preoperatively. The results revealed that mean surface asymmetry index (SAD was 0. 36 and mean surface regularity index (SRI) 0. 79. Simulated keratometry reading (Sim K) was 44. 46 D, and 43. 56 D. Minimun K reading was 42. 60 D. The same patterns of corneal topography in both eyes were 50% in 60 patients who had binocular examination....

  4. Bessel Function Model for Corneal Topography

    CERN Document Server

    Okrasiński, Wojciech

    2011-01-01

    In this paper we consider a new nonlinear mathematical model for corneal topography formulated as two-point boudary value problem. We derive it from first physical principles and provide some mathematical analysis. The existence and uniqeness theorems are proved as well as various estimates on exact solution. At the end we fit the simplified model based on Modified Bessel Function of the First Kind with the real corneal data consisting of matrix of 123x123 points and obtain an error of order of 1%.

  5. Colletotrichum graminicola: a new corneal pathogen.

    Science.gov (United States)

    Ritterband, D C; Shah, M; Seedor, J A

    1997-05-01

    We report the first case of an ocular infection with the fungus Colletotrichum graminicola causing keratitis in a 27-year-old man. Twenty-four months after a postoperative course complicated by recurrent fungal keratitis requiring two penetrating keratoplasties, two anterior chamber washouts, a conjunctival flap, and medical treatment with topical natamycin, intracameral amphotericin B, and oral fluconazole. The patient has shown no signs of fungal recurrence despite a failed corneal graft. C. graminicola is a new corneal pathogen and should be included in the differential diagnosis of mycotic keratitis.

  6. Research on inhibition of corneal neovascularization

    Directory of Open Access Journals (Sweden)

    Zhang-Hui Yang

    2015-12-01

    Full Text Available Corneal transparency is the basis of the normal physiological functions.However, corneal neovascularization(CNVmay occur in the infection, mechanical and chemical injury or under other pathological conditions,which make the cornea lose original transparency and severe visual impairment. In recent years, along with the development of immunology, molecular biology, biochemistry and other disciplines, there is more in-depth understanding on the CNV, and clinical treatment of CNV has made new breakthroughs. This article provides an overview of the inhibition of CNV.

  7. Thermosensitive chitosan-based hydrogels releasing stromal cell derived factor-1 alpha recruit MSC for corneal epithelium regeneration.

    Science.gov (United States)

    Tang, Qiaomei; Luo, Chenqi; Lu, Bing; Fu, Qiuli; Yin, Houfa; Qin, Zhenwei; Lyu, Danni; Zhang, Lifang; Fang, Zhi; Zhu, Yanan; Yao, Ke

    2017-10-01

    Corneal epithelium integrity depends on continuous self-renewing of epithelium and connections between adjacent cells or between the cells and the basement membrane. Self-renewing epithelium cells mainly arise from the continuous proliferation and differentiation of the basal layer and limbal stem cells. The aim of the present study was to generate a bioactive, thermosensitive chitosan-gelatin hydrogel (CHI hydrogel) by incorporating exogenous recombinant human stromal cell-derived factor-1 alpha (SDF-1 alpha) for corneal epithelium regeneration. The exogenous SDF-1 alpha could enhance the stem cells proliferation, chemotaxis and migration, and the expression levels of related genes were significantly elevated in LESCs and mesenchymal stem cells (MSCs) in vitro. Moreover, the MSCs promoted the proliferation and maintained the corneal fate of the LESCs. The rat alkali injury model was used for in vivo study. The injured eyes were covered with CHI hydrogel alone or rhSDF-1 alpha-loaded CHI hydrogel. All rats were followed for 13days. Histological examination showed that the SDF-1 alpha/CHI hydrogel complex group had a nearly normal thickness; moreover, it was also found that this group could upregulate the expression of some genes and had more ΔNp63-positive cells. The SDF-1 alpha/CHI hydrogel complex group had a more tightly arranged epithelium compared with the control group using transmission electron microscopy (TEM). The mechanism for this may have involved the activation of stem cell homing and the secretion of growth factors via the SDF-1/CXCR4 chemokine axis. Therefore, SDF-1 alpha/CHI hydrogel complexes could provide a new idea for the clinical application. The clarity of cornea is important for normal vision. The loss or dysfunction of LESCs leads to the impairment of corneal epithelium. The complete regeneration of corneal epithelium has not been achieved. Our study demonstrated that the incorporation of rhSDF-1 alpha with CHI hydrogel accelerated corneal

  8. Reversible corneal toxicity of retained intracameral Perfluoro-n-octane

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    Saad S Alharbi

    2016-01-01

    Full Text Available A 58-year-old female presented with intracameral retained perfluoro-n-octane (PFO following previous retinal reattachment surgery. After 4 years of follow-up without related sequelae, the patient complained of a gradual decrease in vision secondary to corneal edema with whitish corneal precipitate inferiorly corresponding to the area of retained PFO. Three weeks after anterior chamber washout, corneal edema resolved and the patient obtained 20/40 visual acuity. Even though PFO considered to have a relatively good safety profile, early anterior chamber washout may prevent corneal toxicity and avoid later persistent corneal decompensation.

  9. Current status of accelerated corneal cross-linking

    Directory of Open Access Journals (Sweden)

    Michael Mrochen

    2013-01-01

    Full Text Available Corneal cross-linking with riboflavin is a technique to stabilize or reduce corneal ectasia, in diseases such as keratoconus and post-laser-assisted in situ keratomileusis (LASIK ectasia. There is an interest by patient as well as clinicians to reduce the overall treatment time. Especially, the introduction of corneal cross-linking in combination with corneal laser surgery demands a shorter treatment time to assure a sufficient patient flow. The principles and techniques of accelerated corneal cross-linking is discussed.

  10. Hydration of gelatin molecules in glycerol-water solvent and phase diagram of gelatin organogels.

    Science.gov (United States)

    Sanwlani, Shilpa; Kumar, Pradip; Bohidar, H B

    2011-06-09

    We present a systematic investigation of hydration and gelation of the polypeptide gelatin in water-glycerol mixed solvent (glycerol solutions). Raman spectroscopy results indicated enhancement in water structure in glycerol solutions and the depletion of glycerol density close to hydration sheath of the protein molecule. Gelation concentration (c(g)) was observed to decrease from 1.92 to 1.15% (w/v) while the gelation temperature (T(g)) was observed to increase from 31.4 to 40.7 °C with increase in glycerol concentration. Data on hand established the formation of organogels having interconnected networks, and the universal gelation mechanism could be described through an anomalous percolation model. The viscosity of sol diverged as η ∼ (1 - c(g)/c)(-k) as c(g) was approached from below (c c(g)). It is important to note that values determined for critical exponents k and t were universal; that is, they did not depend on the microscopic details. The measured values were k = 0.38 ± 0.10 and t = 0.92 ± 0.17 whereas the percolation model predicts k = 0.7-1.3 and t = 1.9. Isothermal frequency sweep studies showed power-law dependence of gel storage modulus (G') and loss modulus (G'') on oscillation frequency ω given as G'(ω) ∼ ω(n') and G''(ω) ∼ ω(n''), and consistent with percolation model prediction it was found that n' ≈ n'' ≈ δ ≈ 0.73 close to gelation concentration. We propose a unique 3D phase diagram for the gelatin organogels. Circular dichroism data revealed that the gelatin molecules retained their biological activity in these solvents. Thus, it is shown that the thermomechanical properties of these organogels could be systematically tuned and customized as per application requirement.

  11. Corneal invasion of ocular surface squamous neoplasia after clear corneal phacoemulsification: in vivo confocal microscopy analysis.

    Science.gov (United States)

    Balestrazzi, Angelo; Martone, Gianluca; Pichierri, Patrizia; Tosi, Gian Marco; Caporossi, Aldo

    2008-06-01

    We describe an unusual case of ocular surface squamous neoplasia (OSSN) that occurred in a male patient after superonasal clear corneal phacoemulsification with extensive papillomatous corneal invasion near a side port. The features of the macroscopic invasion of the corneal superficial layers were analyzed by in vivo confocal analysis using the Heidelberg Retina Tomograph II. After OSSN was diagnosed, topical mitomycin-C 0.02% eyedrops were prescribed 4 times a day in a cyclic manner (3 cycles of 1 week on drops followed by 1 week off). After 1 month (second cycle), the natural visual acuity was 20/20, the corneal epithelium had healed completely, and the limbal lesion had regressed markedly. The patient remained asymptomatic without recurrence during a 6-month follow-up.

  12. Corneal heat scar caused by photodynamic therapy performed through an implanted corneal inlay.

    Science.gov (United States)

    Mita, Mariko; Kanamori, Tomomi; Tomita, Minoru

    2013-11-01

    A 60-year-old man had a combination of laser in situ keratomileusis and Kamra corneal inlay implantation to correct presbyopia. Although the outcome was favorable postoperatively, central serous chorioretinopathy was observed in the left eye along with a decrease in the uncorrected (UDVA) and corrected (CDVA) distance visual acuities and the corrected near visual acuity (CNVA). Photodynamic therapy (PDT) was later performed in a university hospital. After PDT, the patient experienced a decline in the visual acuity and came to our clinic a month after the PDT. Degeneration and a scar were observed at the location of the inlay due to the heat and burning. Flattening of the corneal topography was also observed where the corneal scar was located, along with a significant decrease in CDVA in the left eye. Prior to any surgery in which the corneal inlay is an impediment, surgeons should take advantage of the reversibility of the Kamra inlay by explanting the inlay.

  13. Controlled Fabrication of Gelatin Nanoparticles as Drug Carriers

    Science.gov (United States)

    Jahanshahi, M.; Sanati, M. H.; Minuchehr, Z.; Hajizadeh, S.; Babaei, Z.

    2007-08-01

    In recent years, significant effort has been devoted to develop nanotechnology for drug delivery since it offers a suitable means of delivering small molecular weight drugs, as well as macromolecules such as proteins, peptides or genes by either localized or targeted delivery to the tissue of interest. Nanotechnology focuses on formulating therapeutic agents in biocompatible nanocomposites such as nanoparticles, nanocapsules, micellar systems, and conjugates. Protein nanoparticles (BSA, HAS and gelatin) generally vary in size from 50-300 nm and they hold certain advantages such as greater stability during storage, stability in vivo, non-toxicity, non-antigen and ease to scale up during manufacture over the other drug delivery systems. The primary structure of gelatin offers many possibilities for chemical modification and covalent drug attachment. Here nanoparticles of gelatin type A were prepared by a two-step desolvation method as a colloidal drug delivery system and the essential parameters in fabrication were considered. Gelatin was dissolved in 25 mL distilled water under room temperature range. Then acetone was added to the gelatin solution as a desolvating agent to precipitate the high molecular weight (HMW) gelatin. The supernatant was discarded and the HMW gelatin re-dissolved by adding 25 mL distilled water and stirring at 600 rpm. Acetone were added drop-wise to form nanoparticles. At the end of the process, glutaraldehyde solution was used for preparing nanoparticles as a cross-linking agent, and stirred for 12h at 600 rpm. For purification stage we use centrifuge with 600rpm for 3 times. The objective of the present study is consideration of some factors such as temperature, gelatin concentration, agitation speed and the amount of acetone and their effects on size and distribution of nanoparticles. Among the all conditions, 60° C, 50 mg/ml gelatin concentration, 75 ml acetone had the best result and the nanoparticle size was under 170 nm. The effect

  14. The Effect of Corneal Epithelium on Corneal Curvature in Patients with Keratoconus.

    Science.gov (United States)

    Akcay, Emine Kalkan; Uysal, Betul Seher; Sarac, Ozge; Ugurlu, Nagehan; Yulek, Fatma; Cagil, Nurullah; Aslan, Nabi

    2015-01-01

    To investigate the effects of corneal epithelium on corneal curvature in patients with keratoconus. This is a prospective, nonrandomized study. Fifty-nine eyes of 47 patients diagnosed as keratoconus and for whom corneal collagen crosslinking (CXL) was recruited in this study. This study is a single-center clinical trial. Pregnancy, lactation, connective tissue disease, corneal thickness below 350 μm, severe dry eyes, or scar of corneal surgery were exclusion criteria. Before and during CXL procedure after removing the corneal epithelium, maximum values of corneal apical curvature, simulated keratometry 1 (Sim-K1), simulated keratometry 2 (Sim-K2), temporal and inferior curvature values, all of which are 1.5 mm from the corneal center, were calculated. These values before and after removal of epithelium were compared statistically. Mean age of patients was 23.30 ± 5.5 (12-38) years. Twenty-eight (59%) were male while 19 (41%) were female. Mean values measured before and after removing the corneal epithelium were: apical curvature; 59.19 ± 7.2 (47.06-82.40) diopter (D) and 61.70 ± 8.8 (49.19-92.66) D (p = 0.001), SimK1; 47.57 ± 4.3 (39.14-64.57) D and 48.23 ± 4.3 (41.89-66.70) D (p = 0.001), SimK2; 52.04 ± 5.3 (43.56-69.34) D and 53.34 ± 5.6 (43.73-70.89) D (p = 0.001), inferior curvature; 53,85 ± 5.2 (43.47-76.56) D and 55.05 ± 5.8 (44.56-81.93) D (p = 0.002), temporal curvature 49.49 ± 5.1 (41.50-71.03) D and 51.53 ± 5.4 (41.58-73.34) D (p = 0.001), respectively. In keratoconus patients during CXL treatment, after removing the corneal epithelium, more steepness is detected in the curvature of the steeper area of the cornea. When evaluating patients with keratoconus, the masking effect of corneal epithelium on values of curvature should be taken into consideration.

  15. Congenital Unilateral Corneal Anaesthesia with Microphthalmos: A Case Report

    Directory of Open Access Journals (Sweden)

    George Voyatzis

    2012-01-01

    Full Text Available Congenital corneal anaesthesia (CCA is an uncommon condition difficult to diagnose. We report the case of a 20-month-old boy who presented with unilateral congenital corneal anaesthesia. The child was referred with a persistent corneal epithelial defect, unresponsive to symptomatic local treatment for over 10 months. Intensive topical treatment and strict corneal protection led to quick corneal healing. Congenital corneal anaesthesia occurs either alone or in association with neurological diseases or systemic congenital abnormalities. It is important to search for corneal anaesthesia in children with chronic ulcerations of the cornea and self-inflicted injuries. Early diagnosis and treatment are important due to the risk of poor visual prognosis. Management of CCA should aim for the prevention of epithelial defects and is a life-long process.

  16. Corneal Higher Order Aberrations in Granular, Lattice and Macular Corneal Dystrophies

    Science.gov (United States)

    Yagi-Yaguchi, Yukari; Yamaguchi, Takefumi; Okuyama, Yumi; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun

    2016-01-01

    Purpose To evaluate the corneal higher-order aberrations (HOAs) in granular, lattice and macular corneal dystrophies. Methods This retrospective study includes consecutive patients who were diagnosed as granular corneal dystrophy type2 (GCD2; 121 eyes), lattice corneal dystrophies type 1, type 3A (LCDI; 20 eyes, LCDIIIA; 32 eyes) and macular corneal dystrophies (MCD; 13 eyes), and 18 healthy control eyes. Corneal HOAs were calculated using anterior segment optical coherence tomography, and the correlations between HOAs and visual acuity were analyzed. Results HOAs of the total cornea within 4 mm diameter were significantly larger in GCD2 (0.17 ± 0.35 μm), in LCDI (0.33 ± 0.27), LCDIIIA (0.61 ± 1.56) and in MCD (0.23 ± 0.18), compared with healthy controls (0.09 ± 0.02μm, all P GCD2 (0.32 ± 0.48), in LCDI (0.60 ± 0.46), LCDIIIA (0.83 ± 2.29) and in MCD (0.44 ± 0.24), compared with healthy controls (0.19 ± 0.06, all P GCD2, there was no significant correlation between logMAR and HOAs (r = 0.113, P = 0.227). In MCD, LCDI and LCDIIIA, logMAR was positively significantly correlated with HOAs (r = 0.620 and P = 0.028, r = 0.587 and P = 0.007, r = 0.614 and P < 0.001, respectively). Conclusions Increased HOAs occur in eyes with corneal dystrophies, especially in eye with LCD and MCD. Larger amount corneal HOAs are associated with poorer visual acuity in patients with LCD and MCD. PMID:27536778

  17. Gelatin/chitosan biofilm: preparation and characterization; Biofilme gelatina/quitosana: preparacao e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, Luciane da C.; Nunes, Raquel A.; Diniz, Nadie K.S. [Engenharia de Materiais, Universidade Federal de Campina Grande - UFCG, Campina Grande, PB (Brazil); Braga, Carla R.C. [Programa de Pos-graduacao em Ciencia e Engenharia de Materiais da UFCG, Campina Grande, PB (Brazil); Silva, Suedina M. de Lima, E-mail: suedina@dema.ufcg.edu.br [Unidade Academica de Engenharia de Materiais da UFCG, Campina Grande (Brazil)

    2011-07-01

    In this study, gelatin, chitosan and gelatin/chitosan bio films using the ratio of gelatin/chitosan (50/50) were prepared by casting method. The bio films prepared were characterized by X-ray diffraction, scanning electron microscopy and dissolution ratio. According to the results, the incorporation of chitosan into gelatin indicate the decrease of crystallinity of chitosan, a compact structure without large pores and that the dissolution of gelatin/chitosan film is little influenced by hot water than gelatin films. (author)

  18. The relationship between central corneal thickness and corneal curvature in adult Nigerians

    Directory of Open Access Journals (Sweden)

    E. Iyamu

    2011-12-01

    Full Text Available Purpose: The aim of this study was to provide average values for central corneal thickness (CCT and corneal curvature (CC and also to determine a regression model for the relationship between CCT and CC in adult Nigerians without glaucoma.Methods: A total of 95 subjects consisting of 56 males and 39 females aged between 20 and 69 years with mean age of 47.1 ± 14.1 years were recruited for the study. Central corneal thickness was measured by ultrasound pachymetry (SW-1000P ultrasound pachymeter, Tianjin Suowei Electronic Technology, China and corneal curvature was measured by keratometry (Bausch & Lomb keratometer H-135A, USA.Results: The average values of 550.1 ± 33.1µm and 43.0 ± 1.1 D were obtained for CCT and CC respectively. CCT significantly correlated with age (p=0.01, and the regression model predicts a decrease of 6.0 µm in CCT per decade. No significant association was found between CC and age (p=0.56. Also, no significant association was found between CCT and CC (p=0.07. Female subjects had significantly steeper corneas than their male counterparts.Conclusion: Central corneal thickness decreases with increasing age. Neither CCT nor age appear to be significantly correlated with corneal curvature. (S Afr Optom 2011 70(1 44-50

  19. CORNEAL STROMAL THINNING: A RARE CORNEAL COMPLICATION AFTER BARE SCL ERA PTERYG I UM EXCISION TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Sulaiman Abdul

    2015-06-01

    Full Text Available INTRODUCTION : Bare sclera technique without using any anti - mitotic drugs are commonly employed in rural population. Corneal dellen formation and recurrence of pterygium are more common in these cases. But the corneal complication like stromal thinning, necrosis of corne a and sclera are not common. The corneal epithelium is a highly differentiated cell type that is self - renewing. Also corneal epithelium is important for the stromal replacement in the situations like chemical, thermal burns, ocular surgery like pterygium s urgery. Interference with status of stem cell replacement and as a consequent to it, stromal thinning is occurring in the pterygium surgery. P atient 1: A 68 yr s. old male patient underwent pterygium surgery ( B aresclera excision technique. After 30 days he developed corneal thinning with the punched out partial stromal loss without perforation or descmetocele or scleral thinning. Patient 2: A 60yr s. old male patient underwent pterygium surgery 2months back, he developed same type of corneal thinning. Both P atients were treated with tear drops and improved. CONCLUSION : The stromal thinning in these two cases is may be due to chemical factors like collagenase which might have been released from the traumatised conjunctival epithelial cells causing thinning wit hout replacement of stroma by limbal stem cells.

  20. Quantitative proteomic analysis of mice corneal tissues reveals angiogenesis-related proteins involved in corneal neovascularization.

    Science.gov (United States)

    Shen, Minqian; Tao, Yimin; Feng, Yifan; Liu, Xing; Yuan, Fei; Zhou, Hu

    2016-07-01

    Corneal neovascularization (CNV) was induced in Balb/c mice by alkali burns in the central area of the cornea with a diameter of 2.5mm. After fourteen days, the cornea from one eye was collected for histological staining for CNV examination, while the cornea from the other eye of the same mouse was harvested for proteomic analysis. The label-free quantitative proteomic approach was applied to analyze five normal corneal tissues (normal group mice n=5) and five corresponding neovascularized corneal tissues (model group mice n=5). A total of 2124 proteins were identified, and 1682 proteins were quantified from these corneal tissues. Among these quantified proteins, 290 proteins were significantly changed between normal and alkali burned corneal tissues. Of these significantly changed proteins, 35 were reported or predicted as angiogenesis-related proteins. Then, these 35 proteins were analyzed using Ingenuity Pathway Analysis Software, resulting in 26 proteins enriched and connected to each other in the protein-protein interaction network, such as Lcn-2, αB-crystallin and Serpinf1 (PEDF). These three significantly changed proteins were selected for further Western blotting validation. Consistent with the quantitative proteomic results, Western blotting showed that Lcn-2 and αB-crystallin were significantly up-regulated in CNV model, while PEDF was down-regulated. This study provided increased understanding of angiogenesis-related proteins involved in corneal vascular development, which will be useful in the ophthalmic clinic of specifically target angiogenesis.

  1. A brief history of corneal transplantation: From ancient to modern

    Directory of Open Access Journals (Sweden)

    Alexandra X Crawford

    2013-01-01

    Full Text Available This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD. Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17 th and 18 th centuries, true scientific and surgical experimentation in this field did not begin until the 19 th century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of

  2. A brief history of corneal transplantation: From ancient to modern.

    Science.gov (United States)

    Crawford, Alexandra Z; Patel, Dipika V; McGhee, Charles Nj

    2013-09-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17(th) and 18(th) centuries, true scientific and surgical experimentation in this field did not begin until the 19(th) century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of corticosteroids. Recent

  3. Effects of Gelatinization of Enteral Nutrients on Human Gastric Emptying

    Science.gov (United States)

    Kawasaki, Naruo; Urashima, Mitsuyoshi; Odaira, Hironori; Noro, Takuji; Suzuki, Yutaka

    2010-01-01

    Background Gastrointestinal side effects, particularly diarrhea, are still the main reasons for discontinuation of enteral nutrition. Gelatinization of liquid meal for the prevention of diarrhea has been reported as effective. The purpose of this study was to investigate the effects of gelatinization of liquid meal on gastric emptying. Methods Ten healthy volunteers were studied two times, with 2-week interval between tests. The total calorific value was set at 225 kcal, and 3 test meals were prepared: liquid meal and 2 types of gelatinized meals. These 2 types of gelatinized meals are different viscosity. 13C-sodium acetate (100 mg) was thoroughly mixed, and exhaled air was sampled. The results of gastric emptying were expressed as the time of peak excretion (Tmax), and absorption was expressed as the area under the 13CO2 curve up to Tmax (AUC-Tmax). At the same time, blood samples were collected to measure levels of blood glucose, insulin and gastrin. Results The mean value of Tmax were 52.0, 77.3 and 85.6 min. Compared to liquid meal, gastric emptying for gelatinized meals was significantly delayed. The mean value of AUC-Tmax were 22.7, 28.7 and 33.7%dose, respectively, and no significant differences in absorption were seen. No significant differences existed in blood glucose, gastrin and insulin. Conclusions Gelatinization of liquid meal delays gastric emptying. Gelatinized liquid meal may be useful for the management of diarrhea accompanied with enteral nutrition without influencing gastrointestinal hormone and blood glucose. PMID:27942287

  4. Corneal injuries from liquid detergent pods.

    Science.gov (United States)

    Gray, Michael E; West, Constance E

    2014-10-01

    Laundry and dishwasher detergent "pods" were introduced to the United States market in 2010 and are sold by several manufacturers. They represent a high percentage of household cleaning product exposure in the United Kingdom. We present a consecutive case series of 10 children seen in a 9-month period with corneal injuries from exposure to liquid detergent pods.

  5. Evaluation and Treatment of Perioperative Corneal Abrasions

    Directory of Open Access Journals (Sweden)

    Kira L. Segal

    2014-01-01

    Full Text Available Purpose. To evaluate perioperative risk factors for corneal abrasion (CA and to determine current care for perioperative CA in a tertiary care setting. Methods. Hospital-based, cross-sectional study. In Operating Room and Post-Anesthesia Care Units patients, a comparison of cases and controls was evaluated to elucidate risk factors, time to treatment, and most common treatments prescribed for corneal abrasions. Results. 86 cases of corneal abrasion and 89 controls were identified from the 78,542 surgical procedures performed over 2 years. Statistically significant risk factors were age (P=0.0037, general anesthesia (P<0.001, greater average estimated blood loss (P<0.001, eyes taped during surgery (P<0.001, prone position (P<0.001, trendelenburg position (P<0.001, and supplemental oxygen en route to and in the Post-Anesthesia Care Units (P<0.001. Average time to complaint was 129 minutes. 94% of cases had an inpatient ophthalmology consult, with an average time to consult of 164 minutes. The most common treatment was artificial tears alone (40%, followed by combination treatment of antibiotic ointment and artificial tears (35.3%. Conclusions. Trendelenburg positioning is a novel risk factor for CA. Diagnosis and treatment of perioperative corneal abrasions by an ophthalmologist typically require three hours in the tertiary care setting.

  6. Serological profile of candidates for corneal donation

    Directory of Open Access Journals (Sweden)

    Adroaldo Lunardelli

    2014-10-01

    Full Text Available Objetive: The purpose of this study is to map the serological profile of candidates to corneal donation at Irmandade Santa Casa de Misericórdia de Porto Alegre, identifying the percentage of disposal by serology and the marker involved. Methods: There have been analised – retrospectively – the results of serology of all corneal donors, made between the period of 1st january 2006 and 31st december 2012. Data analised were related to age, gender and the results of serology pertinent to viral markers (HBsAg, anti-HBc, anti-HCV and anti-HIV, these, determined by immunosorbent tests (ELISA. Results: In the period of the study, there were 2476 corneal donors at the institution, with a major incidence on the male gender, on an average of 58.7 years old. 23% of retention because of serological unfitness was also identified, that is, 570 samples were non-negative to any of the used tests. The marker anti- HBc was the most prevalent on the studied population, followed by the Hepatitis C virus (HCV and by the Human Immunodeficiency Virus (HIV. Conclusion: From the data found through this study, it is essential to have the participation of an efficient service on the serological evaluation of the candidates to corneal donation, once the security of the receptor must be taken into consideration in a population of donors with 23% of unfitness prevalence, in which the most prevalent marker is the one of Hepatits B.

  7. Peptide Amphiphiles in Corneal Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Martina Miotto

    2015-08-01

    Full Text Available The increasing interest in effort towards creating alternative therapies have led to exciting breakthroughs in the attempt to bio-fabricate and engineer live tissues. This has been particularly evident in the development of new approaches applied to reconstruct corneal tissue. The need for tissue-engineered corneas is largely a response to the shortage of donor tissue and the lack of suitable alternative biological scaffolds preventing the treatment of millions of blind people worldwide. This review is focused on recent developments in corneal tissue engineering, specifically on the use of self-assembling peptide amphiphiles for this purpose. Recently, peptide amphiphiles have generated great interest as therapeutic molecules, both in vitro and in vivo. Here we introduce this rapidly developing field, and examine innovative applications of peptide amphiphiles to create natural bio-prosthetic corneal tissue in vitro. The advantages of peptide amphiphiles over other biomaterials, namely their wide range of functions and applications, versatility, and transferability are also discussed to better understand how these fascinating molecules can help solve current challenges in corneal regeneration.

  8. Corneal topography measurements for biometric applications

    Science.gov (United States)

    Lewis, Nathan D.

    The term biometrics is used to describe the process of analyzing biological and behavioral traits that are unique to an individual in order to confirm or determine his or her identity. Many biometric modalities are currently being researched and implemented including, fingerprints, hand and facial geometry, iris recognition, vein structure recognition, gait, voice recognition, etc... This project explores the possibility of using corneal topography measurements as a trait for biometric identification. Two new corneal topographers were developed for this study. The first was designed to function as an operator-free device that will allow a user to approach the device and have his or her corneal topography measured. Human subject topography data were collected with this device and compared to measurements made with the commercially available Keratron Piccolo topographer (Optikon, Rome, Italy). A third topographer that departs from the standard Placido disk technology allows for arbitrary pattern illumination through the use of LCD monitors. This topographer was built and tested to be used in future research studies. Topography data was collected from 59 subjects and modeled using Zernike polynomials, which provide for a simple method of compressing topography data and comparing one topographical measurement with a database for biometric identification. The data were analyzed to determine the biometric error rates associated with corneal topography measurements. Reasonably accurate results, between three to eight percent simultaneous false match and false non-match rates, were achieved.

  9. Aspergillus terreus recovered from a corneal scraping.

    Science.gov (United States)

    Campbell, Suzanne

    2014-01-01

    A 52 year old, healthy male presented to his optometrist complaining of redness and irritation in the right eye. A foreign body was removed from the eye. The patient was started on ophthalmic solutions of vigamox and systane. At 48 hours, the patient reported increased redness, limited vision, and yellow discharge from the eye. The patient was referred to an ophthalmologist for further evaluation. Physical assessment revealed a superlative central infiltrate (extreme, centrally located injury that had permeated the cornea), diffuse corneal haze, and edema with a 3- to 4+ conjunctival injection and a 1 millimeter hypopyon (an effusion of pus into the anterior chamber of the eye). Corneal scrapings were collected for aerobic and anaerobic bacterial and fungal cultures. The patient was then prescribed. vancomycin, tobramycin, and natamycin ophthalmic eyedrops. On day three, fungal culture results indicated possible fungal forms seen. On day 12, results from the fungal culture of the corneal scraping revealed the causative agent to be Aspergillus terreus. Voriconazole eyedrops were added to the treatment regimen and continued for 10 weeks. The physician order for a fungal culture as well as laboratory data providing the final identification of Aspergillus terreus and laboratory comments indicating an elevated minimum inhibitory concentration (MIC) (> 2 microg/mL) to amphotericin B is associated with treatment failure positively impacted the patient outcome. After completion of the treatment regimen, a photo-therapeutic keratectomy (PTK) was performed in an attempt to remove the dense corneal scarring caused by the fungal infection.

  10. [Purulent corneal ulcers: etiology, pathogenesis, classification].

    Science.gov (United States)

    Kasparova, Evg A

    2015-01-01

    Advanced purulent corneal ulcer, as well as abscess, is a serious vision-threatening condition notable for its fulminant course and possible loss of the eye due to endophthalmitis. Its leading causes, pathogenesis, and classifications are described and analyzed in this paper.

  11. Change in corneal curvature induced by surgery

    NARCIS (Netherlands)

    G. van Rij (Gabriel)

    1987-01-01

    textabstractThe first section deals with the mechanisms by which sutures, incisions and intracorneal contact lenses produce a change in corneal curvature. To clarify the mechanisms by which incisions and sutures produce astigmatism, we made incisions and placed sutures in the corneoscleral limbus of

  12. Autophagy in granular corneal dystrophy type 2.

    Science.gov (United States)

    Choi, Seung-Il; Kim, Eung Kweon

    2016-03-01

    Autophagy is a lysosomal degradative process that is essential for cellular homeostasis and metabolic stress adaptation. Defective autophagy is involved in the pathogenesis of many diseases including granular corneal dystrophy type 2 (GCD2). GCD2 is an autosomal dominant disorder caused by substitution of histidine for arginine at codon 124 (R124H) in the transforming growth factor β-induced gene (TGFBI) on chromosome 5q31. Transforming growth factor β-induced protein (TGFBIp) is degraded by autophagy, but mutant-TGFBIp accumulates in autophagosomes and/or lysosomes, despite significant activation of basal autophagy, in GCD2 corneal fibroblasts. Furthermore, inhibition of autophagy induces cell death of GCD2 corneal fibroblasts through active caspase-3. As there is currently no pharmacological treatment for GCD2, development of novel therapies is required. A potential strategy for preventing cytoplasmic accumulation of mutant-TGFBIp in GCD2 corneal fibroblasts is to enhance mutant-TGFBIp degradation. This could be achieved by activation of the autophagic pathway. Here, we will consider the role and the potential therapeutic benefits of autophagy in GCD2, with focus on TGFBIp degradation, in light of the recently established role of autophagy in protein degradation.

  13. Polysaccharide coating of human corneal endothelium

    DEFF Research Database (Denmark)

    Schroder, H D; Sperling, S

    1977-01-01

    Electron microscopy revealed the presence of a 600-1500 A thick layer of polysaccharide on the surface of human corneal endothelial cells. The surface layer was visualized by combined fixation and staining in a mixture of ruthenium red and osmium tetroxide. The coating material was stable...

  14. Traumatic wound dehiscence after corneal keratoplasty

    Directory of Open Access Journals (Sweden)

    Patrick Frensel Tzelikis

    2015-10-01

    Full Text Available ABSTRACTPurpose:To assess patient characteristics, risk factors, outcomes, and the treatment of wound dehiscence (WD in patients after corneal keratoplasty.Methods:Retrospective chart review of 11 eyes of 11 patients with corneal grafts who underwent repair of WD from January 1, 2004 to December 31, 2012 at Hospital Oftalmologico de Brasilia.Results:Eight (72.7% patients were men and three were women. Six (54.5% patients had deep anterior lamellar keratoplasty (DALK and 5 had penetrating keratoplasty. The mean age at trauma was 31.1 years. The mean time from corneal keratoplasty to WD was 12.82 months (range, 3-33 months. The mean best-corrected visual acuity of patients before trauma was 20/60 (0.48 logMAR and after final treatment was 20/160 (0.90 logMAR (P=0.15. In one case, visual acuity decreased to no light perception because of retinal detachment and phthisis bulbi. Accidental blunt trauma and fall were the most common causes of WD.Conclusion:Patients who undergo corneal keratoplasty have a life-long risk of WD. The full-thickness rupture at the graft-host junction in our study suggests that the junction remains vulnerable, even following DALK, and can rupture with trauma. In our series, depending upon the severity of the trauma, postkeratoplastic WD can be associated with a good visual prognosis.

  15. Past and present of corneal refractive surgery

    DEFF Research Database (Denmark)

    Vestergaard, Anders Højslet

    Surgical correction of refractive errors is becoming increasingly popular. In the 1990s, the excimer laser revolutionized the field of corneal refractive surgery with PRK and LASIK, and lately refractive lenticule extraction (ReLEx) of intracorneal tissue, using only a femtosecond laser, has become...

  16. Oxygen-deficient metabolism and corneal edema.

    Science.gov (United States)

    Leung, B K; Bonanno, J A; Radke, C J

    2011-11-01

    Wear of low-oxygen-transmissible soft contact lenses swells the cornea significantly, even during open eye. Although oxygen-deficient corneal edema is well-documented, a self-consistent quantitative prediction based on the underlying metabolic reactions is not available. We present a biochemical description of the human cornea that quantifies hypoxic swelling through the coupled transport of water, salt, and respiratory metabolites. Aerobic and anaerobic consumption of glucose, as well as acidosis and pH buffering, are incorporated in a seven-layer corneal model (anterior chamber, endothelium, stroma, epithelium, postlens tear film, contact lens, and prelens tear film). Corneal swelling is predicted from coupled transport of water, dissolved salts, and especially metabolites, along with membrane-transport resistances at the endothelium and epithelium. At the endothelium, the Na+/K+ - ATPase electrogenic channel actively transports bicarbonate ion from the stroma into the anterior chamber. As captured by the Kedem-Katchalsky membrane-transport formalism, the active bicarbonate-ion flux provides the driving force for corneal fluid pump-out needed to match the leak-in tendency of the stroma. Increased lactate-ion production during hypoxia osmotically lowers the pump-out rate requiring the stroma to swell to higher water content. Concentration profiles are predicted for glucose, water, oxygen, carbon dioxide, and hydronium, lactate, bicarbonate, sodium, and chloride ions, along with electrostatic potential and pressure profiles. Although the active bicarbonate-ion pump at the endothelium drives bicarbonate into the aqueous humor, we find a net flux of bicarbonate ion into the cornea that safeguards against acidosis. For the first time, we predict corneal swelling upon soft-contact-lens wear from fundamental biophysico-chemical principles. We also successfully predict that hypertonic tear alleviates contact-lens-induced edema.

  17. Investigating Linear and Nonlinear Viscoelastic behaviour and microstructures of Gelatine-Multiwalled carbon nanotubes composites

    KAUST Repository

    Yang, Zhi

    2015-12-01

    We have investigated the linear and nonlinear rheology of various gelatine-multiwalled carbon nanotube (gel-MWNT) composites, namely physically-crosslinked-gelatine gel-MWNT composites, chemically-crosslinked-gelatine gel-MWNT composites, and chemically-physically-crosslinked-gelatine gel-MWNT composites. Further, the internal structures of these gel-MWNT composites were characterized by ultra-small angle neutron scattering and scanning electron microscopy. The adsorption of gelatine onto the surface of MWNT is also investigated to understand gelatine-assisted dispersion of MWNT during ultrasonication. For all gelatine gels, addition of MWNT increases their complex modulus. The dependence of storage modulus with frequency for gelatine-MWNT composites is similar to that of the corresponding neat gelatine matrix. However, by incorporating MWNT, the dependence of the loss modulus on frequency is reduced. The linear viscoelastic region is decreased approximately linearly with the increase of MWNT concentration. The pre-stress results demonstrate that the addition of MWNT does not change the strain-hardening behaviour of physically-crosslinked gelatine gel. However, the addition of MWNT can increase the strain-hardening behaviour of chemically-crosslinked gelatine gel, and chemically-physically crosslinked gelatine gel. Results from light microscopy, cryo-SEM, and USANS demonstrate the hierarchical structures of MWNT, including that tens-of-micron scale MWNT agglomerates are present. Furthermore, the adsorption curve of gelatine onto the surface of MWNT follows two-stage pseudo-saturation behaviour.

  18. Recent advancement of gelatin nanoparticles in drug and vaccine delivery.

    Science.gov (United States)

    Sahoo, Nityananda; Sahoo, Ranjan Ku; Biswas, Nikhil; Guha, Arijit; Kuotsu, Ketousetuo

    2015-11-01

    Novel drug delivery system using nanoscale materials with a broad spectrum of applications provides a new therapeutic foundation for technological integration and innovation. Nanoparticles are suitable drug carrier for various routes of administration as well as rapid recognition by the immune system. Gelatin, the biological macromolecule is a versatile drug/vaccine delivery carrier in pharmaceutical field due to its biodegradable, biocompatible, non-antigenicity and low cost with easy availability. The surface of gelatin nanoparticles can be modified with site-specific ligands, cationized with amine derivatives or, coated with polyethyl glycols to achieve targeted and sustained release drug delivery. Compared to other colloidal carriers, gelatin nanoparticles are better stable in biological fluids to provide the desired controlled and sustained release of entrapped drug molecules. The current review highlights the different formulation aspects of gelatin nanoparticles which affect the particle characteristics like zeta potential, polydispersity index, entrapment efficacy and drug release properties. It has also given emphasis on the major applications of gelatin nanoparticles in drug and vaccine delivery, gene delivery to target tissues and nutraceutical delivery for improving the poor bioavailabity of bioactive phytonutrients.

  19. Electrospun gelatin/polyurethane blended nanofibers for wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Eun; Heo, Dong Nyoung; Lee, Jung Bok; Kwon, Il Keun [Department of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Jong Ryul; Park, Sang Hyuk [Conservative Dentistry and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Jeon, Seong Ho, E-mail: kwoni@khu.ac.k [College of Pharmacy, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2009-08-15

    In this study, we prepared a blended nanofiber scaffold using synthetic and natural polymers, polyurethane (PU) and gelatin respectively, using the electrospinning method to prepare a material for wound dressing. In order to confirm the properties of this gelatin/PU blended nanofiber scaffold, we performed scanning electron microscopy, atomic force microscopy, attenuated total reflectance Fourier-transform infrared spectroscopy, thermal gravimetric analysis, contact angle, water uptake, mechanical property, recovery, and degradation tests, and cellular response. The results obtained indicate that the mean diameter of these nanofibers was uniformly electrospun and ranged from 0.4 to 2.1{mu}m. According to the results, when the amount of gelatin in the blended solution decreased, the contact angle increased and water uptake of the scaffold decreased concurrently. In the mechanical tests, the blended nanofibrous scaffolds were elastic, and elasticity increased as the total amount of PU increased. Moreover, as the total amount of gelatin increased, the cell proliferation increased with the same amount of culture time. Therefore, this gelatin/PU blended nanofiber scaffold has potential application for use as a wound dressing.

  20. A Novel Tissue Adhesive Composed of Modified Gelatin and Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Xiumei MO; Hiroo IWATA; Yoshito IKADA

    2000-01-01

    A two-component adhesive glue was prepared from gelatin and polysaccharides. Gelatin was modified with ethylenediamine (ED) in the presence of water soluble carbodiimine (WSC) to introduce more amino groups into the original gelatin, while dextran and hydroxyethyl-starch (HES) were oxidized by sodium periodate to convert neighbouring hydroxyl groups into dialdehyde groups. Upon mixing the two polymer components in aqueous solution, Schiff's base reaction occurred between the amino groups in the modified gelatin and the aldehyde groups in the modified polysaccharides to give intermolecular crosslinking and gel formation. This new glue showed a capability to stop bleeding and seal tissues when a cut liver of rat was used for hemostatic experiments. It could also form a gel much faster than fibrin glue in in-vitro experiments. The fastest gel formation took place within 2 sec and the bonding strength to porcine skin was about 225gf/cm2 when an amino-gelatin (55% amino) and an aldehyde-HES (>84% dialdehyde) was mixed. In contrast, the gelation time and bonding strength of fibrin gluewere 5 seconds and 120gf/cm2, respectively. The effective adhesive properties have also been identified by the animal experiments of rat.

  1. Massive consumption of gelatinous plankton by Mediterranean apex predators.

    Science.gov (United States)

    Cardona, Luis; Álvarez de Quevedo, Irene; Borrell, Assumpció; Aguilar, Alex

    2012-01-01

    Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus), little tunny (Euthynnus alletteratus), spearfish (Tetrapturus belone) and swordfish (Xiphias gladius). Loggerhead sea turtles (Caretta caretta) in the oceanic stage and ocean sunfish (Mola mola) also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix), blue shark (Prionace glauca), leerfish (Lichia amia), bonito (Sarda sarda), striped dolphin (Stenella caerueloalba) and loggerhead sea turtles (Caretta caretta) in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus) were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga), amberjack (Seriola dumerili), blue butterfish (Stromaeus fiatola), bullet tuna (Auxis rochei), dolphinfish (Coryphaena hyppurus), horse mackerel (Trachurus trachurus), mackerel (Scomber scombrus) and pompano (Trachinotus ovatus) were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage) and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish), most of them with shrinking populations due to overfishing.

  2. Using glucosamine to improve the properties of photocrosslinked gelatin scaffolds.

    Science.gov (United States)

    Suo, Hairui; Xu, Kedi; Zheng, Xiaoxiang

    2015-02-01

    The use of hydrogel-based cell transport scaffolds holds great promise in regenerative medicine, such as treating osteoarthritis. Gelatin and glucosamine are the ideal materials to be used in the hydrogel scaffolds for cartilage regeneration for they could act as compositions of cartilage. To overcome the weak strength of traditional gelatin hydrogels and down-regulate cell toxicity of glucosamine, gelatin and glucosamine molecules were grafted with acrylate groups and covalently crosslinked under photo-radiation to form hydrogels. Hydrogels with tuning physiochemical properties were produced according to different proportions of methacrylate gelatin (GelMA) and N-acryloyl glucosamine (AGA). The process of photocrosslinking was elaborated, and the hypothesis of increasing AGA concentration leading to higher strength of hydrogels was corroborated by testing rheological property and scanning micro-morphological features. A serial of properties, including smaller swelling ratio, lower gelatin dissolution and slower degradation of GelMA/AGA hydrogels with higher AGA concentration further proved our hypothesis. Moreover, AGA molecules showed less cytotoxicity than unmodified glucosamine molecules and the incorporation of AGA molecules in GelMA/AGA hydrogels upregulated cell adhesion and spreading on the hydrogel surface. All of these results indicated that addition of AGA molecules could significantly alter the physiochemical properties of GelMA/AGA hydrogels, which may have broad application prospects in the future.

  3. Massive consumption of gelatinous plankton by Mediterranean apex predators.

    Directory of Open Access Journals (Sweden)

    Luis Cardona

    Full Text Available Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus, little tunny (Euthynnus alletteratus, spearfish (Tetrapturus belone and swordfish (Xiphias gladius. Loggerhead sea turtles (Caretta caretta in the oceanic stage and ocean sunfish (Mola mola also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix, blue shark (Prionace glauca, leerfish (Lichia amia, bonito (Sarda sarda, striped dolphin (Stenella caerueloalba and loggerhead sea turtles (Caretta caretta in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga, amberjack (Seriola dumerili, blue butterfish (Stromaeus fiatola, bullet tuna (Auxis rochei, dolphinfish (Coryphaena hyppurus, horse mackerel (Trachurus trachurus, mackerel (Scomber scombrus and pompano (Trachinotus ovatus were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish, most of them with shrinking populations due to overfishing.

  4. Effect of gelatinization on gastric emptying and absorption.

    Science.gov (United States)

    Kawasaki, Naruo; Suzuki, Yutaka; Urashima, Mitsuyoshi; Nakayoshi, Tomoko; Tsuboi, Kazuto; Tanishima, Yuichiro; Hanyu, Nobuyoshi; Kashiwagi, Hideyuki

    2008-01-01

    For gastrointestinal functional analysis such as gastric emptying tests, either a liquid or solid meal is used as a test meal. Only a few studies have compared meal characteristics, such as liquid and solid. No previous study has compared test meals that had the same composition but different properties. The aim of this study was to compare the gastric emptying and absorption obtained by 13C-breath test after ingestion of liquid or gelatinized liquid nutrients. Ten healthy volunteers were studied four times, with 2-week intervals. For the test meal, 200 mL of liquid meals (200 kcal) and gelatinized liquid meals were used. Gelatinized liquid nutrients were prepared by mixing 6 g, 12 g and 18 g of Natural psyllium husk with 200 mL of liquid meals. Breath samples were collected for four hours. Gastric emptying were expressed as the time of peak excretion, absorption were expressed as the area under the 13CO2 curve up to the time of peak excretion. Gastric emptying times were 54.5, 54.5, 81.7 and 93.3 min. Absorption was 20.8, 20.9, 27.8 and 29.8% dose. Gelatinization influences gastric emptying, but does not influence absorption. Gelatinized liquid meals may be useful for a substitute for solid meals on gastrointestinal functional analysis.

  5. The interaction between tea polyphenols and rice starch during gelatinization.

    Science.gov (United States)

    Wu, Yue; Lin, Qinlu; Chen, Zhengxing; Xiao, HuaXi

    2011-12-01

    The interaction between tea polyphenols (TPLs) and rice starch (RS) during gelatinization has been studied. In the RVA analysis, TPLs-fortified RS exhibited no clearly defined peak viscosity and hot paste viscosity. After excluding other factors, irregular viscosity changes were attributed to the strong interactions between RS and TPLs during pasting/gelatinization. Subsequently, the coupling constants of samples A (the gelatinized sample of the blend of 16% TPLs and RS) and B (the blend of 16% TPLs and gelatinized RS sample) in (1)H-NMR measurements were found to be the difference. Sample A had two coupling constants, (26h)J(HH) = 82.08, 100.77 Hz and (6h)J(HH) = 35.57 Hz, whereas Sample B had one larger coupling constant, (9h)J(HH) = 140.24 Hz. This implied that these two samples differed in H-H interaction and interaction strength of sample A may be stronger than that of sample B. More important is, sample A had clearly broadened O-H stretching and frequency red-shifts of C-O-H bending as compared with sample B in quantitative FT-IR analysis. The overall results indicate that TPLs and RS can have hydrogen bonding interaction during gelatinization.

  6. Investigations on the Chemical Degradation of Silver Gelatine Prints

    Directory of Open Access Journals (Sweden)

    Maha Ahmed ALI

    2012-06-01

    Full Text Available Photographs are considered composite objects with complex chemical and physical structures. Therefore they are more prone to damage as compared to other objects. Chemical degradation is by far the most common decay form found among photographic collections. This study investigates the chemical degradation of silver gelatin prints (DOP and the reaction of the image, silver, gelatin, and paper to accelerated aging, to the action of light, and oxidizing gases, in terms of their physical and chemical nature. The test materials used are properly washed and poorly washed grayscale, black-and-white processed images on photographic paper (Black & White Photographic Paper BH 0 Bromofort 6P0661 Tropical from Forte Photochemical Company Vác, Hungary. After exposure, the results were studied by means of visual inspection, amino acid analyzer, Fourier transform infrared and transmission electron microscope. The results were compared with those of the control samples. Our study revealed that the image, silver, gelatin and photographic paper are greatly affected by oxidizing agents and that the effect increased if the photographic prints were inadequately washed at the time of their processing. Furthermore, our results indicated that an increased amount of ammonia and amino acid in the silver gelatin print is a reliable indicator of the degradation of its gelatine emulsion.

  7. Meat & bone meal extract and gelatin as renewable flocculants.

    Science.gov (United States)

    Piazza, G J; Garcia, R A

    2010-01-01

    Readily available proteins were tested as renewable flocculants, and their actions were compared to that of anionic PAM, a common, commercial flocculant that requires the coaddition of a calcium ion source. Two soy proteins, a whey fraction, a porcine gelatin, and a meat & bone meal (MBM) extract were used in the flocculation test. It was found that MBM extract and porcine gelatin promoted clay flocculation, and flocculation was complete by 24h with or without the addition of calcium chloride. The other tested proteins did not promote clay flocculation, but all of the proteins were found to be adsorbed to clay. The protein adsorptions were well described by the Langmuir model, and gelatin and MBM extract had higher maximum adsorption capacities than the other proteins. Zwitterionic buffer solutions at pH 5.5, 7.0, and 10.0 were tested in the flocculation experiments. Addition of the pH 5.5 buffer caused the two soy proteins to become clay flocculants and lowered the concentration of gelatin and MBM extract necessary to promote complete flocculation by 24h. Calcium chloride was not required for flocculation. Under optimal testing conditions, the dried weight of gelatin or MBM extract was 2.6 and 17 times higher, respectively, than the weight of anionic PAM required for complete flocculation at 24h.

  8. Partial-thickness corneal tissue restoration after a chemical burn

    Directory of Open Access Journals (Sweden)

    Galan A

    2016-04-01

    Full Text Available Alessandro Galan, Anton Giulio Catania, Giuseppe Lo Giudice San Paolo Ophthalmic Center, San Antonio Hospital, Padova, Italy Purpose: We describe a case of full-thickness corneal restoration after an acute corneal burn with an acid agent. Methods: A 32-year-old male reported painful discomfort, redness, photophobia, and a decrease in visual acuity in the left eye after a unilateral burn with an acid agent. Slit-lamp examination revealed massive corneal melting involving necrotic sequestrum of the entire corneal surface. Surgical approach was carried out in order to preserve residual ocular tissues. Results: Extensive corneal–conjunctival layer curettage of the necrotic tissue was performed showing perfectly clear undamaged deep lamellar corneal layers. The patient underwent multilayered amniotic membrane transplantation and total capsular–conjunctival flap in order to preserve ocular tissue from further melting or corneal perforation. A complete and spontaneous “restitutio ad integrum” of the corneal layers was shown during the follow-up. The cornea was perfectly clear with restored normal anatomical architecture. Conclusion: In this case, a spontaneous full-thickness corneal tissue restoration occurred after an acute chemical burn. Studies about the mechanisms whereby different cells interact and replicate within the stroma may unveil the biology behind corneal regeneration and transparency. Keywords: amniotic membrane, chemical burn, corneal healing

  9. Emodin ameliorates lipopolysaccharides-induced corneal inflammation in rats

    Institute of Scientific and Technical Information of China (English)

    Guo-Ling; Chen; Jing-Jing; Zhang; Xin; Kao; Lu-Wan; Wei; Zhi-Yu; Liu

    2015-01-01

    · AIM: To investigate the effect of emodin on pseudomonas aeruginosa lipopolysaccharides(LPS)-induced corneal inflammation in rats.· METHODS: Corneal infection was induced by pseudomonas aeruginosa LPS in Wistar rats. The inflammation induced by LPS were examined by slit lamp microscope and cytological checkup of aqueous humor.Corneal tissue structure was observed by hematoxylin and eosin(HE) staining. The activation of nuclear factor kappa B(NF-κB) was determined by Western blot.Messenger ribonucleic acid(m RNA) of tumor necrosis factor-α(TNF-α) and intercellular adhesion molecule-1(ICAM-1) in LPS-challenged rat corneas were measured with reverse transcription-polymerase chain reaction(RT-PCR).· RESULTS: Typical manifestations of acute corneal inflammation were observed in LPS-induce rat model,and the corneal inflammatory response and structure were improved in rats pretreated with emodin. Treatment with emodin could improve corneal structure, reduce corneal injure by reducing corneal inflammatory response. Emodin could inhibit the decreasing lever of inhibitor of kappa B alpha(IкBα) express, and the m RNA expression of TNF-α and ICAM-1 in corneal tissues was also inhibited by emodin. The differences were statistically significant between groups treated with emodin and those without treatment(P <0.01).·CONCLUSION: Emodin could ameliorate LPS-induced corneal inflammation, which might via inhibiting the activation of NF-κB.

  10. Ocular histopathological changes after eyeball enucleation induced by corneal trauma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To observe the ocular histopathological changes aftereyeball enucleation induced by corneal trauma.Methods: Light microscopic examination was done on 117 eyeball specimens enucleated after corneal trauma (18 with corneal fissure and 99 with corneal perforating trauma).Results: Acute, subacute or chronic inflammatory changes, and fibrous membrane formation were observed in well-closed corneal wounds, whereas inflammation, atrophy and scar were observed in the focal tissues. But at the late period, secondary glaucoma, retinal detachment, endophthalmitis and eyeball atrophy resulted in blindness. Corneal fistula was observed in those with inadequate cure of wounds caused by ingrowth of corneal epithelium, embedment of iris and vitreous body, and large area of centrally located tissue deficiency of the corneal. A high incidence of endophthalmitis was noted due to the presence of corneal fistula. Severe inflammation was observed in the anterior segmental tissues with fibrous infiltration in the anterior chamber, which might result in rapid destruction of the eyeballs.Conclusions: Ocular pathology varies with the difference of the position, form, size and closing conditions of the corneal laceration after trauma.

  11. Anatomical characterization of central, apical and minimal corneal thickness

    Institute of Scientific and Technical Information of China (English)

    Federico; Saenz-Frances; Martha; Cecilia; Bermúdez-Vallecilla; Lara; Borrego-Sanz; Luis; Jaez; J; osé; Marìa; Martinez-de-la-Casa; Laura; Morales-Fernandez; Enrique; Santos-Bueso; Julián; Garcia-Sanchez; Julián; Garcia-Feijoo

    2014-01-01

    ·AIM: To anatomically locate the points of minimum corneal thickness and central corneal thickness(pupil center) in relation to the corneal apex.·METHODS: Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex(AT),minimum corneal thickness(MT) and corneal thickness at the pupil center(PT) were determined using the pentacam. Distances from the corneal apex to MT(MD)and PT(PD) were calculated and their quadrant position(taking the corneal apex as the reference) determined:point of minimum thickness(MC) and point of central thickness(PC) depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume(determined using the Pentacam)and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.·RESULTS: MT was located at a mean distance of 0.909 mm from the apex(79.4% in the inferior-temporal quadrant). PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume(B =-0.024; 95% CI:-0.043 to-0.004). No significant relations were identified in the linear regression model for PD or the multinomial logisticregressions for MC and PC.·CONCLUSION: MT was typically located at the inferiortemporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

  12. Anatomical characterization of central, apical and minimal corneal thickness

    Directory of Open Access Journals (Sweden)

    Federico Saenz-Frances

    2014-08-01

    Full Text Available AIM: To anatomically locate the points of minimum corneal thickness and central corneal thickness (pupil center in relation to the corneal apex.METHODS: Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex (AT, minimum corneal thickness (MT and corneal thickness at the pupil center (PT were determined using the pentacam. Distances from the corneal apex to MT (MD and PT (PD were calculated and their quadrant position (taking the corneal apex as the reference determined:point of minimum thickness (MC and point of central thickness (PC depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume (determined using the Pentacam and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.RESULTS: MT was located at a mean distance of 0.909 mm from the apex (79.4% in the inferior-temporal quadrant. PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume (B=-0.024; 95%CI:-0.043 to -0.004. No significant relations were identified in the linear regression model for PD or the multinomial logistic regressions for MC and PC.CONCLUSION: MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

  13. Corneal collagen cross-linking to stop corneal ectasia exacerbated by radial keratotomy.

    Science.gov (United States)

    Mazzotta, Cosimo; Baiocchi, Stefano; Denaro, Rosario; Tosi, Gian Marco; Caporossi, Tomaso

    2011-02-01

    To assess the efficacy of riboflavin ultraviolet A (UV-A) corneal collagen cross-linking in the management of keratoconic corneal ectasia exacerbated by radial keratotomy (RK). A patient with progressive corneal ectasia and hyperopic shift, occurring 10 years after RK performed in the left eye, was treated with riboflavin UV-A corneal collagen cross-linking according to the Siena protocol: Pilocarpin 0.1% drop (1 hour before), lidocaine 4% drops 15 minutes before, mechanical scraping of epithelium (9-mm-diameter area), preirradiation stromal soaking for 10 minutes in riboflavin 0.1%-dextrane 20% (Ricrolin; Sooft Italy) applied every 2 minutes, and 30 minutes of total exposure (6 steps of 5 minutes) to solid-state UV-A illuminator (Caporossi, Baiocchi, Mazzotta Vega X linker; CSO Opthalmics, Florence, Italy), energy delivered 3 mW/cm, and irradiated area 9 mm in diameter. After the operation, uncorrected visual acuity and best spectacle-corrected visual acuity improved from 0.2 to 0.6 and from 0.3 to 0.8 Snellen lines, respectively, in a 12-month follow-up. Improved topographical K readings and corneal symmetry index were also recorded starting from the first postoperative month and continuing thereafter. No adverse effects were recorded after treatment. Riboflavin UV-A-induced corneal cross-linking seems to be a promising surgical option in the management of unstable corneal ectasia exacerbated by RK, particularly in eyes with preexisting keratoconus. A large cohort and longer follow-up are needed to determine its long-term efficacy in this clinical setting.

  14. Manifestaciones corneales en las enfermedades sistémicas Corneal manifestations in systemic diseases

    Directory of Open Access Journals (Sweden)

    J. Zarranz-Ventura

    2008-01-01

    Full Text Available Un gran número de enfermedades sistémicas presentan manifestaciones corneales dentro de su espectro de enfermedad. El estudio detallado de todos los cuadros que asocian patología corneal resulta inabarcable, por ello se presentan las enfermedades más prevalentes o características. Este estudio contempla las enfermedades pulmonares y conectivopatías (colagenosis, enfermedades reumatológicas y enfermedades inflamatorias idiopáticas, las enfermedades dermatológicas, cardiovasculares, hematológicas y la patología digestiva y hepatopancreática. Se contemplan también, por ocasionar alteraciones corneales, las enfermedades endocrinas y metabólicas con algunas situaciones de malnutrición y estados carenciales, las infecciones sistémicas y las enfermedades renales. Otro área que produce afectación corneal es la patología otorrinolaringológica y las enfermedades genéticas. Se repasa brevemente la toxicidad y las alteraciones corneales provocadas por fármacos.Systemic diseases affecting the cornea have a wide range of manifestations. The detailed study of all pathologies that cause corneal alteration is unapproachable, so we have centered our interest in the most prevalent or characteristic of them. In this paper we have divided these pathologies in sections to facilitate their study. Pulmonar and conective tissue (like colagen, rheumatologic and idiopathic inflamatory diseases, dermatologic, cardiovascular, hematologic, digestive and hepatopancreatic diseases with corneal alteration are described. Endocrine and metabolic diseases, malnutrition and carential states are also studied, as well as some otorhinolaryngologic and genetic diseases that affect the cornea. Finally, a brief report of ocular toxicity induced by drugs is referred.

  15. Enhanced Vascularization in Hybrid PCL/Gelatin Fibrous Scaffolds with Sustained Release of VEGF

    National Research Council Canada - National Science Library

    Wang, Kai; Chen, Xuejiao; Pan, Yiwa; Cui, Yun; Zhou, Xin; Kong, Deling; Zhao, Qiang

    2015-01-01

    .... In this study, fibrous scaffolds that consist of PCL and gelatin fibers were fabricated. The gelatin fibers were further functionalized by heparin immobilization, which provides binding sites for VEGF and thus enables the sustained release of VEGF...

  16. The Preparation of Chitosan Oligosaccharide/Alginate Sodium/Gelatin Nanofibers by Spiral-Electrospinning.

    Science.gov (United States)

    Lu, Weipeng; Xu, Haitao; Zhang, Bing; Ma, Ming; Guo, Yanchuan

    2016-03-01

    A spiral-electrospinning was used to mass-produce gelatin nanofibers with a content of chitosan oligosaccharide (COS) and alginate sodium (AS). Multiple jets were observed to form on the edges of the helix slice-spinneret simultaneously. Important electrospinning parameters, such as concentration of COS/gelatin aqueous solution, rotational velocity of spinneret and spinning distance, were examined to investigate the electrospinnability of COS/gelatin solution and the morphology of COS/gelatin nanofiber membranes. Due to the poor miscibility between COS and AS, COS/AS/gelatin nanofiber membranes were obtained from COS/gelatin solution and AS/gelatin solution by mixing electrospinning with multi-spinnerets. The novel needleless electrospinning not only avoided the possibility of nozzle-clogging, but also prepared COS/AS/gelatin nanofibers on a large scale for a wide variety of applications.

  17. Investigating Effects of Gelatin-Chitosan Film on Culture of Bone Marrow Stromal Cells in Rat

    Directory of Open Access Journals (Sweden)

    A Karami joyani

    2015-02-01

    Conclusion: Results of proliferation,differentiation and apoptosis cultured BMSCs on a gelatin-chitosan film showed that gelatin-chitosan film can be used as a good model of a biodegradable scaffold in tissue engineering and cell therapy.

  18. Antioxidative activity and emulsifying properties of cuttlefish skin gelatin modified by oxidised phenolic compounds

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Eun, J.B.; Wierenga, P.A.; Gruppen, H.

    2009-01-01

    Antioxidative activity and emulsifying properties of cuttlefish skin gelatin modified by different oxidised phenolic compounds including caffeic acid, ferulic acid and tannic acid at different concentrations were investigated. Oxidised phenolic compounds were covalently attached to gelatin as indica

  19. Detection of porcine DNA in gelatine and gelatine-containing processed food products-Halal/Kosher authentication.

    Science.gov (United States)

    Demirhan, Yasemin; Ulca, Pelin; Senyuva, Hamide Z

    2012-03-01

    A commercially available real-time PCR, based on a multi-copy target cytochrome b (cyt b) using porcine specific primers, has been validated for the Halal/Kosher authentication of gelatine. Extraction and purification of DNA from gelatine were successfully achieved using the SureFood® PREP Animal system, and real-time PCR was carried out using SureFood® Animal ID Pork Sens kit. The minimum level of adulteration that could be detected was 1.0% w/w for marshmallows and gum drops. A small survey was undertaken of processed food products such as gum drops, marshmallows and Turkish delight, believed to contain gelatine. Of fourteen food products from Germany, two samples were found to contain porcine gelatine, whereas of twenty-nine samples from Turkey twenty-eight were negative. However, one product from Turkey contained porcine DNA and thus was not Halal, and neither was the use of porcine gelatine indicated on the product label.

  20. Gelatin-Based Films and Coatings for Food Packaging Applications

    Directory of Open Access Journals (Sweden)

    Marina Ramos

    2016-09-01

    Full Text Available This review discusses the latest advances in the composition of gelatin-based edible films and coatings, including nanoparticle addition, and their properties are reviewed along their potential for application in the food packaging industry. Gelatin is an important biopolymer derived from collagen and is extensively used by various industries because of its technological and functional properties. Nowadays, a very wide range of components are available to be included as additives to improve its properties, as well as its applications and future potential. Antimicrobials, antioxidants and other agents are detailed due to the fact that an increasing awareness among consumers regarding healthy lifestyle has promoted research into novel techniques and additives to prolong the shelf life of food products. Thanks to its ability to improve global food quality, gelatin has been particularly considered in food preservation of meat and fish products, among others.

  1. Characterization of gelatin-sodium alginate complex coacervation system

    Directory of Open Access Journals (Sweden)

    Shinde Ujwala

    2009-01-01

    Full Text Available A gelatin and sodium alginate complex coacervation system was studied and an effect of pH and colloid mixing ratios on coacervation was investigated. A colloid mixing ratio at which optimum coacervation occurred varied with the coacervation pH. Viscometric, turbidity and coacervate dry yield investigations were used to investigate optimum conditions for complex coacervation. Optimum coacervation occurred at pH 3.5 at a gelatin sodium alginate ratio 4:1. Coacervate and equilibrium fluid was analyzed for gelatin and sodium alginate contents and yields calculated on the basis of chemical analysis showed that optimum coacervation occurred at 25% sodium alginate fraction at pH 3.5.

  2. Novel formulations of ballistic gelatin. 1. Rheological properties.

    Science.gov (United States)

    Zecheru, Teodora; Său, Ciprian; Lăzăroaie, Claudiu; Zaharia, Cătălin; Rotariu, Traian; Stănescu, Paul-Octavian

    2016-06-01

    Ballistic gelatin is the simulant of the human body during field tests in forensics and other related fields, due to its physical and mechanical similarities to human trunk and organs. Since the ballistic gelatin used in present has important issues to overcome, an alternative approach is the use of gelatin-polymer composites, where a key factor is the insertion of biocompatible materials, which replicate accurately the human tissues. In order to be able to obtain an improved material in terms of mechanical performances by an easy industrial-scale technology, before the verification of the ballistic parameters by shooting in agreement with military standards, one of the best and cheapest solutions is to perform a thorough check of their rheological properties, in standard conditions.

  3. Evaluating conditions for the formation of chitosan/gelatin microparticles

    Directory of Open Access Journals (Sweden)

    Marcia C. Silva

    2009-06-01

    Full Text Available Chitosan/gelatin microparticles were prepared by complex coacervation. Three chitosan (CH samples, with different acetylation degrees and intrinsic viscosities, were used together with commercial gelatin (G samples. Microparticles formation was investigated at various CH/G ratios, within the pH range of 3.5 to 6.0. Reactions were carried out at 40 and 60 ºC, for 2, 4, and 6 hours. Turbidity measurements performed at 633 nm were used to monitor the process. The resulting curves revealed maximum values, which were correlated to the glucosamine content of CH samples. After isolation, yields were determined, and the microparticles were characterized by infrared spectroscopy (FTIR and thermogravimetry (TGA. Both techniques evidenced the formation of coacervate microparticles. The highest yields in microparticles were determined for the system comprising the CH sample with the lowest degree of acetylation and intrinsic viscosity, and the gelatin sample with the lowest bloom strength.

  4. Pressure-induced gelatinization of starch in excess water.

    Science.gov (United States)

    Vallons, Katleen J R; Ryan, Liam A M; Arendt, Elke K

    2014-01-01

    High pressure processing is a promising non-thermal technology for the development of fresh-like, shelf-stable foods. The effect of high pressure on starch has been explored by many researchers using a wide range of techniques. In general, heat and pressure have similar effects: if sufficiently high, they both induce gelatinization of starch in excess water, resulting in a transition of the native granular structure to a starch paste or gel. However, there are significant differences in the structural and rheological properties between heated and pressurized starches. These differences offer benefits with respect to new product development. However, in order to implement high-pressure technology to starch and starch-containing products, a good understanding of the mechanism of pressure-induced gelatinization is necessary. Studies that are published in this area are reviewed, and the similarities and differences between starches gelatinized by pressure and by temperature are summarized.

  5. Scaling laws of gelatin hydrogels for steady dynamic friction

    Science.gov (United States)

    Gupta, Vinit; Singh, Arun K.

    2016-09-01

    In this article, we use population balance based dynamic friction model for steady sliding to develop scaling laws in the terms of mesh size of gelatin hydrogels. First of all, it is observed in the sliding experiments that shear modulus of gelatin hydrogels depends on sliding velocity. This dependence is more evident in the case of low sliding velocity. Moreover, relaxation time constant of a dangling chain at the sliding interface scales with the same exponent as its stiffness. The scaling law is also developed for chain density and viscous retardation at the sliding interface. It is also established that the Hookean-based dynamic friction model is sufficient to study frictional behaviour of hydrogels. The reason for this observation is attributed to the weak bonding between a gelatin hydrogel and glass interface.

  6. Interferometer for measuring dynamic corneal topography

    Science.gov (United States)

    Micali, Jason Daniel

    The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. It is desirable to possess an instrument that can measure the corneal shape and tear film surface with the same accuracy and resolution that is currently performed on common optical elements. A dual interferometer system for measuring the dynamic corneal topography is designed, built, and verified. The completed system is validated by testing on human subjects. The system consists of two co-aligned polarization splitting Twyman-Green interferometers designed to measure phase instantaneously. The primary interferometer measures the surface of the tear film while the secondary interferometer simultaneously tracks the absolute position of the cornea. Eye motion, ocular variation, and a dynamic tear film surface will result in a non-null configuration of the surface with respect to the interferometer system. A non-null test results in significant interferometer induced errors that add to the measured phase. New algorithms are developed to recover the absolute surface topography of the tear film and corneal surface from the simultaneous interferometer measurements. The results are high-resolution and high-accuracy surface topography measurements of the in vivo cornea that are captured at standard camera frame rates. This dissertation will cover the development and construction of an interferometer system for measuring the dynamic corneal topography of the human eye. The discussion starts with the completion of an interferometer for measuring the tear film. The tear film interferometer is part of an

  7. THE COMBINATION OF GELATIN WITH HYDROCHLORIC ACID : II. NEW DETERMINATIONS OF THE ISOELECTRIC POINT AND COMBINING CAPACITY OF A PURIFIED GELATIN.

    Science.gov (United States)

    Hitchcock, D I

    1929-03-20

    1. Cooper's gelatin purified according to Northrop and Kunitz exhibited a minimum of osmotic pressure and a maximum of opacity at pH 5.05 +/-0.05. The pH of solutions of this gelatin in water was also close to this value. It is inferred that such gelatin is isoelectric at this pH and not at pH 4.70. 2. Hydrogen electrode measurements with KCl-agar junctions were made with concentrated solutions of this gelatin in HCl up to 0.1 M. The combination curve calculated from these data is quite exactly horizontal between pH 2 and 1, indicating that 1 gm. of this gelatin can combine with a maximum of 9.35 x 10(-4) equivalents of H(+). 3. Conductivity titrations of this gelatin with HCl gave an endpoint at 9.41 (+/-0.05) x 10(-4) equivalents of HCl per gram gelatin. 4. E.M.F. measurements of the cell without liquid junction, Ag, AgCl, HCl + gelatin, H(2), lead to the conclusion that this gelatin in 0.1 M HCl combines with a maximum of 9.4 x 10(-4) equivalents of H(+) and 1.7 x 10(-4) equivalents of Cl(-) per gram gelatin.

  8. Photofabricated gelatin-based nerve conduits: nerve tissue regeneration potentials.

    Science.gov (United States)

    Gámez, Eduardo; Goto, Yoshinobu; Nagata, Kengo; Iwaki, Toru; Sasaki, Tomio; Matsuda, Takehisa

    2004-01-01

    There is a strong demand for development of nerve guide conduit with prompt nerve regeneration potential for injury-induced nerve defect. Prior to study on nerve tissue engineering using Schwann cells or nerve stem cells, the effectiveness of photofabricated scaffolds based on photocurable gelatin was examined. This study describes the evaluation of in vivo nerve tissue regeneration potentials of three custom-designed and -fabricated prostheses (inner diameter, 1.2 mm; outer diameter, 2.4 mm; wall thickness, 0.60 mm; and length, 15 mm) made of photocured gelatin: a plain photocured gelatin tube (model I), a photocured gelatin tube packed with bioactive substances (laminin, fibronectin, and nerve growth factor) coimmobilized in a photocured gelatin rod (model II), and a photocured gelatin tube packed with bioactive substances coimmobilized in multifilament fibers (model III). These prostheses were implanted between the proximal and distal stumps 10 mm of the dissected right sciatic nerve of 70 adult male Lewis rats for up to 1 year. The highest regenerative potentials were found using the model III prosthesis, followed by the model II prosthesis. Markedly retarded neural regeneration was observed using the model I prosthesis. These were evaluated from the viewpoints of functional recovery, electrophysiological responses, and tissue morphological regeneration. The significance of the synergistic cooperative functions of multifilaments, which serve as a platform that provides contact guidance to direct longitudinal cell movement and tissue ingrowth and as a cell adhesive matrix with high surface area, and immobilized bioactive substances, which enhance nerve regeneration via biological stimulation, is discussed.

  9. Extraction and characterization of gelatin from two edible Sudanese insects and its applications in ice cream making.

    Science.gov (United States)

    Mariod, Abdalbasit Adam; Fadul, Hadia

    2015-07-01

    Three methods were used for extraction of gelatin from two insects, melon bug (Coridius viduatus) and sorghum bug (Agonoscelis versicoloratus versicoloratus). Extraction of insect gelatin using hot water gave higher yield reached up to 3.0%, followed by mild acid extraction which gave 1.5% and distilled water extraction which gave only 1.0%, respectively. The obtained gelatins were characterized by FTIR and the spectra of insect's gelatin seem to be similar when compared with commercial gelatin. Amide II bands of gelatins from melon and sorghum bug appeared around at 1542-1537 cm(-1). Slight differences in the amino acid composition of gelatin extracted from the two insects were observed. Ice cream was made by using 0.5% insect's gelatin and compared with that made using 0.5% commercial gelatin as stabilizing agent. The properties of the obtained ice cream produced using insects gelatin were significantly different when compared with that made using commercial gelatin.

  10. Induction of corneal collagen cross-linking in experimental corneal alkali burns in rabbits

    Directory of Open Access Journals (Sweden)

    Marcello Colombo-Barboza

    2014-10-01

    Full Text Available Objective: To evaluate the effect of riboflavin-ultraviolet-A-induced cross-linking (CXL following corneal alkali burns in rabbits. Methods: The right corneas and limbi of ten rabbits were burned using a 1N solution of NaOH and the animals were then divided into two groups: a control group submitted to clinical treatment alone and an experimental group that was treated 1 h after injury with CXL, followed by the same clinical treatment as administered to the controls. Clinical parameters were evaluated post-injury at 1, 7, 15, and 30 days by two independent observers. Following this evaluation, the corneas were excised and examined histologically. Results: There were no statistically significant differences in clinical parameters, such as hyperemia, corneal edema, ciliary injection, limbal ischemia, secretion, corneal neovascularization, symblepharon, or blepharospasm, at any of the time-points evaluated. However, the size of the epithelial defect was significantly smaller in the CXL group (p<0.05 (day 15: p=0.008 and day 30: p=0.008 and the extent of the corneal injury (opacity lesion was also smaller (day 30: p=0.021. Histopathology showed the presence of collagen bridges linking the collagen fibers in only the CXL group. Conclusions: These results suggest that the use of CXL may improve the prognosis of acute corneal alkali burns.

  11. Spontaneous corneal melting in pregnancy: a case report

    Directory of Open Access Journals (Sweden)

    Arya Sudesh K

    2007-11-01

    Full Text Available Abstract Background To report a case of spontaneous corneal melting in pregnancy. We reviewed the literature on corneal melting and the effect of pregnancy on cornea and collagen containing tissues. Case presentation A 29-year-old woman who underwent radial keratotomy in both eyes followed by trabeculectomy in her left eye developed corneal melting in the same eye, in her seventh month of pregnancy. Despite screening, no infectious or immune mediated condition could be identified. She was managed conservatively with cyanoacrylate glue, bandage contact lens, lubricants and antibiotics. Conclusion It may not always be possible to find the underlying cause of corneal melting but the more common underlying causes should be ruled out by proper investigations. Pregnancy with its host of hormonal changes could potentially have some effect on corneal collagen leading to corneal melting in compromised corneas.

  12. Systemic Immunomodulatory Strategies in High-risk Corneal Transplantation

    Science.gov (United States)

    Abud, Tulio B.; Di Zazzo, Antonio; Kheirkhah, Ahmad; Dana, Reza

    2017-01-01

    The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation.

  13. Indocyanine green staining for the triple corneal procedure.

    Science.gov (United States)

    Kobayashi, Akira; Segawa, Yoji; Nishimura, Akira; Shirao, Yutaka; Sugiyama, Kazuhisa

    2004-01-01

    In the triple corneal procedure, successful completion of capsulorhexis is of the utmost importance. Another use of indocyanine green dye for better visualization of the anterior lens capsule of mature cataract during the triple corneal procedure is described. Four consecutive patients (mean age, 69.5 years) with both mature cataracts and corneal opacity underwent the triple corneal procedure. After trephination of the recipient cornea, the anterior capsule of the lens was stained with indocyanine green. A continuous curvilinear capsulorhexis (CCC) was performed, after which conventional triple corneal procedures were followed. In all four cases, this technique markedly improved visualization of the lens capsule and resulted in successful and easy manipulation of the CCC and subsequent removal of residual lens cortex. Staining of the anterior capsule of mature cataract in the triple corneal procedure clearly defines the border of the capsule, thus allowing easy and complete execution of CCC.

  14. Microencapsulation of sulforaphane from broccoli seed extracts by gelatin/gum arabic and gelatin/pectin complexes.

    Science.gov (United States)

    García-Saldaña, Jesús S; Campas-Baypoli, Olga N; López-Cervantes, Jaime; Sánchez-Machado, Dalia I; Cantú-Soto, Ernesto U; Rodríguez-Ramírez, Roberto

    2016-06-15

    Sulforaphane is a phytochemical that has received attention in recent years due to its chemopreventive properties. However, the uses and applications of this compound are very limited, because is an unstable molecule that is degraded mainly by changes in temperature and pH. In this research, the use of food grade polymers for microencapsulation of sulforaphane was studied by a complex coacervation method using the interaction of oppositely charged polymers as gelatin/gum arabic and gelatin/pectin. The polymers used were previously characterized in moisture content, ash and nitrogen. The encapsulation yield was over 80%. The gelatin/pectin complex had highest encapsulation efficiency with 17.91%. The presence of sulforaphane in the complexes was confirmed by FTIR and UV/visible spectroscopy. The materials used in this work could be a new and attractive option for the protection of sulforaphane.

  15. EXPERIMENTAL STUDY ON THE CORNEAL ENDOTHELIUM OF TRAUMATIC CATARACT

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    The cell morphology of corneal endothelium in 84 mice with experimental traumatic cataract was investigated with stained corneal buttons. In the experimental group, the boundaries between adjacent corneal endothelial cells were significantly distorted, some cell boundaries manifested degenerative changes that led to coalescence of the cells. The mean density and mean area of endothelial cells of the controls showed significant difference from those of the experimental group during the 12 weeks of observ...

  16. Corneal Ectasis among Wrestlers: Report of Two Cases

    OpenAIRE

    Mohammad Ali Zare Mehrjardi; Hadi Zare Mehrjardi; Abasali Gaeeni; Elham Ashrafi; Homa Naderifar

    2014-01-01

    Report keratoconus in two patients with a long history of wrestling without any risk factor for corneal ectasia and reviewing the possible pathogenesis. To confirm suspicion of keratoconus, corneal topography was performed using scanning slit topography system and Orbscan. In two wrestlers with the complaint of visual loss in their eyes and IOP raising, corneal topography was performed and development of keratoconus (KCN) was detected. Athletes involved in sports with high strenuous exercises...

  17. A brief history of corneal transplantation: From ancient to modern

    OpenAIRE

    Alexandra X Crawford; Patel, Dipika V.; Charles NJ McGhee

    2013-01-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by ...

  18. Retinal evaluation and treatment after refractive corneal surgery.

    Science.gov (United States)

    Swinger, C A; Kraushar, M F

    1985-08-01

    Refractive corneal surgery (a collective term used to describe a variety of surgical procedures that alter the refractive status of the eye through the surgical modification of corneal curvature) shows promise for use in situations where current methods of optical correction do not meet the patient's needs. This article reviews our experiences with the retinal evaluation of patients who have undergone corneal refractive surgery and offers recommendations for the treatment of retinal pathology after such surgery.

  19. Organism Isolation in Corneal Ulcer- Utility of Different Techniques

    OpenAIRE

    M Thapa; A.K. Sharma; D.N. Shah; S KC; Shrestha, S.

    2012-01-01

    Introduction: Various techniques are available for isolation of microorganism in cases of microbial keratitis including conventional methods of scraping, re-scraping inoculation in different media and corneal biopsy. Methods: This was a cross sectional descriptive study conducted from February 2002 to July 2003. A total of 161 eyes of corneal ulcers were evaluated with scraping inoculation. Re-scraping and corneal biopsy were performed in those cases which did not grow any organism in t...

  20. New null screen design for corneal topography

    Science.gov (United States)

    Campos-García, Manuel; Estrada-Molina, Amilcar; Díaz-Uribe, Rufino

    2011-09-01

    In this work we report the design of a null screen for corneal topography. Here we assume that the corneal surface is an ellipsoid with a diameter of 12 mm and a curvature radius of 7.8 mm. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with spots (similar to ellipses) drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact radial array of circular spots if the surface is perfect. Additionally, we performed a numerical simulation introducing Gaussian random errors in the coordinates of the centroids of the spots on the image plane, and in the coordinates of the sources (spots on the null-screen) in order to obtain the conical null-screen that reduces the error in the evaluation of the topography.

  1. Corneal Chromoblastomycosis Caused by Fonsecaea pedrosoi

    Directory of Open Access Journals (Sweden)

    Winai Chaidaroon

    2015-02-01

    Full Text Available Purpose: To report 2 unusual cases of fungal keratitis due to Fonsecaea pedrosoi. Methods: Two patients were diagnosed with Fonsecaea pedrosoi keratitis. Their files were reviewed for predisposing factors, clinical characteristics, microbiological study, treatment, and outcome. Results: Two consecutive patients presented with brownish pigmented corneal ulcers in their eyes after sustaining eye trauma from vegetative matter. In both cases, corneal scrapings were collected for microscopic examination and culture. Dematiaceous hyphae were seen on the smears, and dark pigmented colonies grew on the culture media, identified as F. pedrosoi. Both patients were treated and cured with combined topical antifungal agents and oral itraconazole. The first patient required an amniotic membrane patch, while the second received an intracameral amphotericin B injection. Conclusions: Pigmented infiltrates can be an important diagnostic clue, but a microscopic evaluation and culture are required to obtain an accurate diagnosis of Fonsecaea keratitis. The prompt diagnosis and combined antifungal treatment can prevent morbidity associated with this fungal infection.

  2. Prevalence of corneal astigmatism before cataract surgery.

    Science.gov (United States)

    Mohammadi, Mehran; Naderan, Mohammad; Pahlevani, Rozhin; Jahanrad, Ali

    2016-12-01

    The purpose of this study was to describe and analyze the prevalence and pattern of corneal astigmatism in cataract surgery candidates. In a prospective cross-sectional study, preoperative demographics, and keratometric and refractive values of cataract surgery candidates were collected from January 2013 to December 2014. Axial length (AL) and flat and steep keratometry measurements were optically measured by a partial coherence interferometry device (IOLMaster). This study consisted of 2156 eyes of 1317 patients with a mean age of 64.92 ± 11.48 (SD) (30-88 years). The mean of AL was 23.33 ± 1.37 mm, and the mean of corneal astigmatism was 1.12 ± 1.10 diopter (D) (range 0.0-7.00), in all patients. Furthermore, the mean of flat and steep keratometry were 43.70 ± 1.70 and 44.83 ± 1.79 D, respectively. Corneal astigmatism was 1.50 D or less in 1590 eyes (73.7 %), more than 1.50 D in 566 eyes (26.2 %), 3.00 D or more in 161 eyes (7.4 %), WTR in 796 eyes (36.9 %), ATR in 1010 eyes (46.8 %), and oblique in 350 eyes (16.2 %). ATR astigmatism axis significantly increased with the increase in age. Corneal astigmatism of most cataract surgery candidates fell between 0.50 and 1.50 D. The results of our study however is confined to our demographics might provide useful data for cataract patients, surgeons, and intraocular lens manufacturers for different purposes.

  3. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    Science.gov (United States)

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Purpose. The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Methods. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. Results. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Conclusion. Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous

  4. RECURRENT CORNEAL EROSION SYNDROME (a review

    Directory of Open Access Journals (Sweden)

    S. V. Trufanov

    2015-01-01

    Full Text Available Recurrent corneal erosion (RCE syndrome is characterized by episodes of recurrent spontaneous epithelial defects. Main clinical symptoms (pain, redness, photophobia, lacrimation occurred at night. Corneal lesions revealed by slit lamp exam vary depending on the presence of corneal epithelium raise, epithelial microcysts or epithelial erosions, stromal infiltrates and opacities. Microtraumas, anterior corneal dystrophies, and herpesvirus give rise to RCE. Other causes or factors which increase the risk of RCE syndrome include meibomian gland dysfunction, keratoconjunctivitis sicca, diabetes, and post-LASIK conditions. Basal membrane abnormalities and instability of epithelial adhesion to stroma play a key role in RCE pathogenesis. Ultrastructural changes in RCE include abnormalities of basal epithelial cells and epithelial basal membrane, absence or deficiency of semi-desmosomes, loss of anchor fibrils. Increase in matrix metalloproteinases and collagenases which contribute to basal membrane destruction results in recurrent erosions and further development of abnormal basal membrane. The goals of RCE therapy are to reduce pain (in acute stage, to stimulate re-epithelization, and to restore «adhesion complex» of basal membrane. In most cases, RCE responds to simple conservative treatment that includes lubricants, healing agents, and eye patches. RCEs that are resistant to simple treatment, require complex approach. Non-invasive methods include long-term contact lens use, instillations of autologous serum (eye drops, injections of botulinum toxin (induces ptosis, antiviral agent use or oral intake of metalloproteinase inhibitors. Cell membrane stabilizers, i.e., antioxidants, should be included into treatment approaches as well. Antioxidant effect of Emoxipine promotes tissue reparation due to the prevention of cell membrane lipid peroxidation as well as due to its anti-hypoxic, angioprotective, and antiplatelet effects. If conservative therapy

  5. Analysis of correlation between corneal topographical data and visual performance

    Science.gov (United States)

    Zhou, Chuanqing; Yu, Lei; Ren, Qiushi

    2007-02-01

    Purpose: To study correlation among corneal asphericity, higher-order aberrations and visual performance for eyes of virgin myopia and postoperative laser in situ keratomileusis (LASIK). Methods: There were 320 candidates 590 eyes for LASIK treatment included in this study. The mean preoperative spherical equivalence was -4.35+/-1.51D (-1.25 to -9.75), with astigmatism less than 2.5 D. Corneal topography maps and contrast sensitivity were measured and analyzed for every eye before and one year after LASIK for the analysis of corneal asphericity and wavefront aberrations. Results: Preoperatively, only 4th and 6th order aberration had significant correlation with corneal asphericity and apical radius of curvature (pcorneal asphericity (pcorneal aberrations had no significant correlation with visual acuity and area under the log contrast sensitivity (AULCSF) (P>0.05). Postoperatively, corneal aberrations still didn't have significant correlation with visual acuity (P>0.05), but had significantly negative correlation with AULCSF (PCorneal asphericity had no significant correlation with AULCSF before and after the treatment (P>0.05). Conclusions: Corneal aberrations had different correlation with corneal profile and visual performance for eyes of virgin myopia and postoperative LASIK, which may be due to changed corneal profile and limitation of metrics of corneal aberrations.

  6. Clinical correlates of common corneal neovascular diseases: a literature review

    Institute of Scientific and Technical Information of China (English)

    Nizar; Saleh; Abdelfattah; Mohamed; Amgad; Amira; A; Zayed; Hamdy; Salem; Ahmed; E; Elkhanany; Heba; Hussein; Nawal; Abd; El-Baky

    2015-01-01

    A large subset of corneal pathologies involves the formation of new vessels(neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization(CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis,contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatment available so far.

  7. Decreased central corneal thickness in ankylosing spondylitis.

    Science.gov (United States)

    Ortak, Huseyin; Inanır, Ahmet; Demir, Selim; Uysal, Alper; Şahin, Şafak; Sağcan, Mustafa; Önder, Yalçın; Alim, Sait; Demir, Ayşe Kevser

    2014-04-01

    Central corneal thickness and dry eye tests were evaluated in a study population consisting of 68 ankylosing spondylitis patients diagnosed according to the modified New York criteria, and 61 age-matched controls without ankylosing spondylitis. A full ophthalmological evaluation was performed on each subject. All subjects were screened for age, gender, HLA-B27, tear break-up time test, Schirmer test, and duration of disease. Central corneal thickness was measured under topical anesthesia with an ultrasonic pachymeter. The mean central corneal thickness was 537.3 ± 30.6 μm, range 462-600 μm, in ankylosing spondylitis patients, whereas it was 551.7 ± 25.2 μm, range 510-620 μm, in controls (p = 0.005). The Schirmer test result was 7.3 ± 5.9 mm for the ankylosing spondylitis patients and 11.7 ± 5.8 mm for the control group (p = 0.002). Tear break-up time was 7.3 ± 3.2 s for the ankylosing spondylitis patients and 14.0 ± 4.5 s for the control group (p ankylosing spondylitis. In addition, attention must be given to lower dry eye tests in surgical interventions such as photorefractive keratectomy and laser in situ keratomileusis in ankylosing spondylitis patients.

  8. Meretoja's Syndrome: Lattice Corneal Dystrophy, Gelsolin Type

    Science.gov (United States)

    Abreu, C.; Neves, M.; Oliveira, L.; Beirão, M.

    2017-01-01

    Lattice corneal dystrophy gelsolin type was first described in 1969 by Jouko Meretoja, a Finnish ophthalmologist. It is caused by an autosomal dominant mutation in gelsolin gene resulting in unstable protein fragments and amyloid deposition in various organs. The age of onset is usually after the third decade of life and typical diagnostic triad includes progressive bilateral facial paralysis, loose skin, and lattice corneal dystrophy. We report a case of a 53-year-old female patient referred to our Department of Ophthalmology by severe dry eye and incomplete eyelid closure. She had severe bilateral facial paresis, significant orbicularis, and perioral sagging as well as hypoesthesia of extremities and was diagnosed with Meretoja's syndrome at the age of 50, confirmed by the presence of gelsolin mutation. At our observation she had bilateral diminished tear film break-up time and Schirmer test, diffuse keratitis, corneal opacification, and neovascularization in the left eye. She was treated with preservative-free lubricants and topical cyclosporine, associated with nocturnal complete occlusion of both eyes, and underwent placement of lacrimal punctal plugs. Ocular symptoms are the first to appear and our role as ophthalmologists is essential for the diagnosis, treatment, and monitoring of ocular alterations in these patients. PMID:28250773

  9. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    GAO Nan; CUI GuangHui; WANG ZhiChong; HUANG Bing; GE Jian; LU Rong; ZHANG KeFei; FAN ZhiGang; LU Li; PENG Zhan

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epidermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immunohistology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epidermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being cocultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  10. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epi-dermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immuno-histology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epi-dermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being co-cultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  11. Development of new therapeutic modalities for corneal endothelial disease focused on the proliferation of corneal endothelial cells using animal models.

    Science.gov (United States)

    Koizumi, Noriko; Okumura, Naoki; Kinoshita, Shigeru

    2012-02-01

    This review describes our recent attempts to develop new therapeutic modalities for corneal endothelial disease using animal models including non-human primate model in which the proliferative ability of corneal endothelial cells is severely limited, as is the case in humans. First, we describe our attempt to develop new surgical treatments using cultivated corneal endothelial cells for advanced corneal endothelial dysfunction. It includes two different approaches; a "corneal endothelial cell sheet transplantation" with cells grown on a type-I collagen carrier, and a "cell-injection therapy" combined with the application of Rho-kinase (ROCK) inhibitor. Recently, it was reported that the selective ROCK inhibitor, Y-27632, promotes cell adhesion and proliferation and inhibits the apoptosis of primate corneal endothelial cells in culture. When cultivated corneal endothelial cells were injected into the anterior chamber of animal eyes in the presence of ROCK inhibitor, endothelial cell adhesion was promoted and the cells achieved a high cell density and a morphology similar to corneal endothelial cells in vivo. We are also trying to develop a novel medical treatment for the early phase of corneal endothelial disease by the use of ROCK inhibitor eye drops. In rabbit and monkey experiments using partial endothelial dysfunction models, corneal endothelial wound healing was accelerated by the topical application of ROCK inhibitor to the ocular surface, and resulted in the regeneration of a corneal endothelial monolayer with a high endothelial cell density. We are now trying to advance the clinical application of these new therapies for patients with corneal endothelial dysfunction.

  12. Manifestaciones corneales en las enfermedades sistémicas Corneal manifestations in systemic diseases

    OpenAIRE

    J. Zarranz-Ventura; E. De Nova; Moreno-Montañés, J

    2008-01-01

    Un gran número de enfermedades sistémicas presentan manifestaciones corneales dentro de su espectro de enfermedad. El estudio detallado de todos los cuadros que asocian patología corneal resulta inabarcable, por ello se presentan las enfermedades más prevalentes o características. Este estudio contempla las enfermedades pulmonares y conectivopatías (colagenosis, enfermedades reumatológicas y enfermedades inflamatorias idiopáticas), las enfermedades dermatológicas, cardiovasculares, hematológi...

  13. Corneal tissue welding with infrared laser irradiation after clear corneal incision.

    Science.gov (United States)

    Rasier, Rfat; Ozeren, Mediha; Artunay, Ozgür; Bahçecioğlu, Halil; Seçkin, Ismail; Kalaycoğlu, Hamit; Kurt, Adnan; Sennaroğlu, Alphan; Gülsoy, Murat

    2010-09-01

    The aim of this study was to investigate the potential of infrared lasers for corneal welding to seal corneal cuts done in an experimental animal model. Full-thickness corneal cuts on freshly enucleated bovine eyes were irradiated with infrared (809-nm diode, 980-nm diode, 1070-nm YLF, and 1980-nm Tm:YAP) lasers to get immediate laser welding. An 809-nm laser was used with the topical application of indocyanine green to enhance the photothermal interaction at the weld site. In total, 60 bovine eyes were used in this study; 40 eyes were used in the first part of the study for the determination of optimal welding parameters (15 eyes were excluded because of macroscopic carbonization, opacification, or corneal shrinkage; 2 eyes were used for control), and 20 eyes were used for further investigation of more promising lasers (YLF and Tm:YAP). Laser wavelength, irradiating power, exposure time, and spot size were the dose parameters, and optimal dose for immediate closure with minimal thermal damage was estimated through histological examination of welded samples. In the first part of the study, results showed that none of the applications was satisfactory. Full-thickness success rates were 28% (2 of 7) for 809-nm and for 980-nm diode lasers and 67% (2 of 3) for 1070-nm YLF and (4 of 6) for 1980-nm Tm:YAP lasers. In the second part of the study, YLF and Tm:YAP lasers were investigated with bigger sample size. Results were not conclusive but promising again. Five corneal incisions were full-thickness welded out of 10 corneas with 1070-nm laser, and 4 corneal incisions were partially welded out of 10 corneas with 1980-nm laser in the second part of the study. Results showed that noteworthy corneal welding could be obtained with 1070-nm YLF laser and 1980-nm Tm:YAP laser wavelengths. Furthermore, in vitro and in vivo studies will shed light on the potential usage of corneal laser welding technique.

  14. Corneal layer plate removal with Fluconazole injected corneal stroma and autologous conjunctival transplantation for keratomycosis

    Directory of Open Access Journals (Sweden)

    Li-Dong Yang

    2013-08-01

    Full Text Available AIM: To investigate the clinical effect of corneal layer plate removal with Fluconazole injected corneal stroma and autologous conjunctival transplantation for keratomycosis.METHODS: There were 168 cases suffered keratomycosis that the focus located shallow of the cornea and was not obvious to drug, who registered in our hospital from March 2005 to June 2010. In surgery we removed plate layer to cormea clear, the region was greater than focus for 0.5mm,then we injected fluconazole which is 2g/L density in corneal stroma to make the edema area greater than Removal of area for 0.5mm. At last we took pedicle conjunctival flap to cover the plant bed by continuous suture. Postoperative day use drug to drop eye and to observe that whether recurrent of the keratomycosis and how was the edema degrade, the blood supply of conjunctival graft pieces, how about the stimulating signs of the surgery eye, the vision.RESULTS: The improvement rate was 96.2% after surgery for seven days and the cure rate was 95.5% after surgery for one months. We found in 157 eyes accepted trigeminy surgery there were 6 eyes recurrence and the recurrence rate was 3.8%. The mean time of corneal stromal edema faded away was 13.4 hours. After surgery for one month there were 39 eyes(24.8%whose vision removed than preoperative, there were 91 eyes(58.0%whose vision were same as preoperative and there were 27 eyes(17.2%whose vision lower than preoperative. In these operations the loss ratio of corneal endothelium was from 0%-8%, the mean was 2.9%. The irritative symptoms postoperative were mild for 87%, moderate for 10% and severe for 3%. By this surgery the mean length of stay was 7.3 days so the mean hospitalization expenses only were 2160 RMB. Three months after surgery, 4 cases were slight corneal ectasia.CONCLUSION: This operation combined corneal layer plate removal, Fluconazole injected corneal stroma and autologous conjunctival transplantation for keratomycosis which was in

  15. Distribution and emission of chloropicrin applied as gelatin capsules

    Science.gov (United States)

    Chloropicrin (CP) is a potential methyl bromide alternative for controlling soil-borne pests. However, the compound is highly volatile that poses strong exposure risks for humans and the environment because of volatile organic compound (VOC) emissions. A gelatin capsule formulation was developed as...

  16. Biopolymers produced from gelatin and other sustainable resources using polyphenols

    Science.gov (United States)

    Several researchers have recently demonstrated the feasibility of producing biopolymers from the reaction of polyphenolics with gelatin in combination with other proteins (e.g. whey) or with carbohydrates (e.g. chitosan and pectin). These combinations would take advantage of the unique properties o...

  17. Preparation of Astaxanthin Nanodispersions Using Gelatin-Based Stabilizer Systems

    Directory of Open Access Journals (Sweden)

    Navideh Anarjan

    2014-09-01

    Full Text Available The incorporation of lipophilic nutrients, such as astaxanthin (a fat soluble carotenoid in nanodispersion systems can either increase the water solubility, stability and bioavailability or widen their applications in aqueous food and pharmaceutical formulations. In this research, gelatin and its combinations with sucrose oleate as a small molecular emulsifier, sodium caseinate (SC as a protein and gum Arabic as a polysaccharide were used as stabilizer systems in the formation of astaxanthin nanodispersions via an emulsification-evaporation process. The results indicated that the addition of SC to gelatin in the stabilizer system could increase the chemical stability of astaxanthin nanodispersions significantly, while using a mixture of gelatin and sucrose oleate as a stabilizer led to production of nanodispersions with the smallest particle size (121.4 ± 8.6 nm. It was also shown that a combination of gelatin and gum Arabic could produce optimal astaxanthin nanodispersions in terms of physical stability (minimum polydispersity index (PDI and maximum zeta-potential. This study demonstrated that the mixture of surface active compounds showed higher emulsifying and stabilizing functionality compared to using them individually in the preparation of astaxanthin nanodispersions.

  18. Prolonged Culture of Aligned Skeletal Myotubes on Micromolded Gelatin Hydrogels

    Science.gov (United States)

    Bettadapur, Archana; Suh, Gio C.; Geisse, Nicholas A.; Wang, Evelyn R.; Hua, Clara; Huber, Holly A.; Viscio, Alyssa A.; Kim, Joon Young; Strickland, Julie B.; McCain, Megan L.

    2016-06-01

    In vitro models of skeletal muscle are critically needed to elucidate disease mechanisms, identify therapeutic targets, and test drugs pre-clinically. However, culturing skeletal muscle has been challenging due to myotube delamination from synthetic culture substrates approximately one week after initiating differentiation from myoblasts. In this study, we successfully maintained aligned skeletal myotubes differentiated from C2C12 mouse skeletal myoblasts for three weeks by utilizing micromolded (μmolded) gelatin hydrogels as culture substrates, which we thoroughly characterized using atomic force microscopy (AFM). Compared to polydimethylsiloxane (PDMS) microcontact printed (μprinted) with fibronectin (FN), cell adhesion on gelatin hydrogel constructs was significantly higher one week and three weeks after initiating differentiation. Delamination from FN-μprinted PDMS precluded robust detection of myotubes. Compared to a softer blend of PDMS μprinted with FN, myogenic index, myotube width, and myotube length on μmolded gelatin hydrogels was similar one week after initiating differentiation. However, three weeks after initiating differentiation, these parameters were significantly higher on μmolded gelatin hydrogels compared to FN-μprinted soft PDMS constructs. Similar results were observed on isotropic versions of each substrate, suggesting that these findings are independent of substrate patterning. Our platform enables novel studies into skeletal muscle development and disease and chronic drug testing in vitro.

  19. Solution Blow Spinning of Food-Grade Gelatin Nanofibers.

    Science.gov (United States)

    Liu, Fei; Avena-Bustillos, Roberto J; Bilbao-Sainz, Cristina; Woods, Rachelle; Chiou, Bor-Sen; Wood, Delilah; Williams, Tina; Yokoyama, Wallace; Glenn, Gregory M; McHugh, Tara H; Zhong, Fang

    2017-06-01

    The primary advantage of nanofibers over larger diameter fibers is the larger surface area to volume ratio. This study evaluated solution blow spinning (SBS) processing conditions for obtaining food-grade gelatin nanofibers from mammalian and fishery byproducts, such as pork skin gelatins (PGs) and high molecular weight fish skin gelatin (HMWFG). HMWFG had a highest intact collagen structure compared to PGs. PGs with different Bloom values, solution viscosities, and surface tensions were compared with HMWFG for their ability to produce nanofibers through SBS. Only HMWFG fibers were obtained irrespective of processing conditions, which looked like fluffy cotton candy. HMWFG nanofibers had round morphologies with a narrower diameter distribution and lower average fiber diameter (AFD) under medium gelatin concentrations, medium air pressures, and medium feed rates. The highest glass transition temperature (Tg ) values were obtained at medium concentrations, medium air pressure, and either high or low feed rate. The thinnest HMWFG nanofibers with an AFD of 80.1 nm and the highest Tg value of 59.0 °C could be formed by combining a concentration of 17.6% (w/v), an air pressure of 0.379 MPa, and a feed rate of 0.06 mL/min from the response surface analysis. HMWFG Brunauer, Emmett, and Teller surface area increased from 221 to 237 m(2) /g, indicating their potential applicability for active compound carrier. © 2017 Institute of Food Technologists®.

  20. Microencapsulation of Eugenol by Gelatin-Sodium Alginate Complex Coacervation

    OpenAIRE

    Ujwala Shinde; Mangal Nagarsenker

    2011-01-01

    Present study describes microencapsulation of eugenol using gelatin-sodium alginate complex coacervation. The effects of core to coat ratio and drying method on properties of the eugenol microcapsules were investigated. The eugenol microcapsules were evaluated for surface characteristics, micromeritic properties, oil loading and encapsulation efficiency. Eugenol microcapsules possessed good flow properties, thus improved handling. The scanning electron photomicrographs showed globular surface...

  1. Gelatine-assisted synthesis of magnetite nanoparticles for magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Alves, André F.; Mendo, Sofia G. [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal); Ferreira, Liliana P. [Universidade de Lisboa, Biosystems and Integrative Sciences Institute, Faculdade de Ciências (Portugal); Mendonça, Maria Helena [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal); Ferreira, Paula [University of Aveiro, Department of Materials and Ceramic Engineering, CICECO - Aveiro Institute of Materials (Portugal); Godinho, Margarida; Cruz, Maria Margarida [Universidade de Lisboa, Biosystems and Integrative Sciences Institute, Faculdade de Ciências (Portugal); Carvalho, Maria Deus, E-mail: mdcarvalho@ciencias.ulisboa.pt [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal)

    2016-01-15

    Magnetite nanoparticles were synthesized by the co-precipitation method exploring the use of gelatine and agar as additives. For comparison, magnetite nanoparticles were also prepared by standard co-precipitation, by co-precipitation with the addition of a surfactant (sodium dodecyl sulphate) and by the thermal decomposition method. The structure and morphology of the synthesized nanoparticles were investigated by powder X-ray diffraction and transmission electron microscopy. Their magnetic properties were studied by SQUID magnetometry and {sup 57}Fe Mössbauer spectroscopy. The nanoparticles potential for applications in magnetic hyperthermia was evaluated through heating efficiency under alternating magnetic field. The results show that all synthesis methods produce Fe{sub 3−x}O{sub 4} nanoparticles with similar sizes. The nanoparticles synthesized in the gelatine medium display the narrowest particle size distribution, the lowest oxidation degree, one of the highest saturation magnetization values and the best hyperthermia efficiency, proving that this gelatine-assisted synthesis is an efficient, environmental friendly, and low-cost method to produce magnetite nanoparticles. Graphical Abstract: A new gelatine-assisted method is an efficient and low-cost way to synthesize magnetite nanoparticles with enhanced magnetic hyperthermia.

  2. Topological Analysis, Modeling, and Imaging of Gelatin-Based Hydrogels

    Science.gov (United States)

    Koga, Maho; Marmorat, Clement; Rafailovich, Miriam; Talmon, Yishai; Zussman, Eyal; Arinstein, Arkadii

    Gelatin is a component of natural biocompatible scaffolds used in tissue engineering constructs. However, due its supra-molecular structure, the mesh size is drastically larger compared to synthetic polymers having the same moduli, and therefore the Rubber Elastic Theory cannot be used to describe properties of gelatin. Gelatin forms distinct fibrils, bundles of triple helix chains, which form rigid areas. We experimented with two different gel moduli, made possible by varying the concentration of microbial transglutaminase (mTG). mTG forms permanent cross links and affects the morphology of the gelatin by changing the number of fibrils formed. Thus, the mesh size calculated from the Rubber Elastic Theory was much smaller than the actual size of the mesh, as measured from cryoscanning electron microscopy images and fluorescent bead particle migration. We also observed the en-mass migration behavior of dermal fibroblast cells as a function of the substrate rheological response. Our results will present the ability of the cells to sense the structure of the underlying substrate, as well as the absolute value of the modulus. Furthermore, the data will be interpreted in terms of a modified theoretical model, which takes into account the structure and mesh size of the gel.

  3. Irradiated gelatin-potato starch blends: evaluation of physicochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Regis, Wellington; Mastro, Nelida L., E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Macromolecular polysaccharides of large chains as starch can interlace with gelatin modifying their mechanical resistance. In this work, biodegradable bovine gelatin-potato starch blends films were developed using glycerol as plasticizer. Three formulations of gelatin/starch proportions (w/w) were used (1:0; 3:1; 1:1) and casting was the chosen method. The dried samples were then submitted to ionizing radiation coming from an electron beam (EB) accelerator with doses of 20 and 40 kGy, at room temperature, in the presence of air. Mechanical properties such as puncture strength and elongation at break were measured. Color measurements, water absorption, moisture, and film solubility were assessed. The results showed that starch addition to films based on gelatin as well as irradiation affected physical and structural properties of the films. Although the increase of starch content in the mixture led to decrease of the puncture force even in samples irradiated with the higher dose, there was a decrease of water absorption of films with the increase of the dose, and also by the higher starch content. Samples irradiated at 20 kGy presented higher moisture and film solubility. The methodology developed in this paper can be applied to other composite systems to establish the best protein:starch ratio, and the contribution of the radiation crosslinking in each specific case. (author)

  4. Rheological evaluation of the irradiated pectin/gelatin mixed systems

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Mastro, Nelida L. del, E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The main biopolymers used in the edible films production are polysaccharides and proteins. Pectin is a heterosaccharidic polymer derived from the vegetal cell wall. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen. The aim of this research was to evaluate the effect of ionizing radiation on either the biopolymers alone or on the mixed systems prepared with high-and low-methoxyl pectin and gelatin in solution and mixed gel. The results showed that gelatin viscosity remained almost unaffected by the irradiation with doses from 1 to 15 kGy, with a slight increase at 3 kGy. On the other hand, there was a sharp decrease of viscosity values of all pectin solutions upon irradiation, being this behavior predominant when both polysaccharides and proteins were present in a mixed system. The gel hardness and gel brittleness of the gelatin were affected by the increase of radiation dose. (author)

  5. Lecithin, gelatin and hydrolyzed collagen orally disintegrating films: functional properties.

    Science.gov (United States)

    Borges, J G; Silva, A G; Cervi-Bitencourt, C M; Vanin, F M; Carvalho, R A

    2016-05-01

    Orally disintegrating films (ODFs) can transport natural active compounds such as ethanol extract of propolis (EEP). This paper aimed to investigate the effect of lecithin on different gelatin and hydrolyzed collagen (HC) polymeric matrices with addition of EEP. ODFs were prepared by casting technique and were characterized (color parameters, water content, mechanical properties, microstructure, disintegration time (DT), infrared spectroscopy (FTIR), contact angle (CA), swelling degree and total phenolic content). The mechanical properties were influenced by HC. The microstructure demonstrated increased porosity and roughness in films with EEP, and the addition of lecithin resulted in an increase in the number of pores. Lecithin-gelatin and lecithin-EEP-gelatin interactions were observed by FTIR. The addition of HC and EEP reduced the DT and CA, and HC and lecithin reduced the swelling capacity. However, the swelling capacity was not affected by presence of EEP. The addition of lecithin to gelatin and HC ODFs may improve the incorporation and the oral transport of active compounds such as EEP. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Anisotropic silk fibroin/gelatin scaffolds from unidirectional freezing

    Energy Technology Data Exchange (ETDEWEB)

    Asuncion, Maria Christine Tankeh, E-mail: christine.asuncion@u.nus.edu [National University of Singapore, Department of Biomedical Engineering (Singapore); Goh, James Cho-Hong [National University of Singapore, Department of Biomedical Engineering (Singapore); National University of Singapore, Department of Orthopedic Surgery (Singapore); Toh, Siew-Lok [National University of Singapore, Department of Biomedical Engineering (Singapore); National University of Singapore, Department of Mechanical Engineering (Singapore)

    2016-10-01

    Recent studies have underlined the importance of matching scaffold properties to the biological milieu. Tissue, and thus scaffold, anisotropy is one such property that is important yet sometimes overlooked. Methods that have been used to achieve anisotropic scaffolds present challenges such as complicated fabrication steps, harsh processing conditions and toxic chemicals involved. In this study, unidirectional freezing was employed to fabricate anisotropic silk fibroin/gelatin scaffolds in a simple and mild manner. Morphological, mechanical, chemical and cellular compatibility properties were investigated, as well as the effect of the addition of gelatin to certain properties of the scaffold. It was shown that scaffold properties were suitable for cell proliferation and that mesenchymal stem cells were able to align themselves along the directed fibers. The fabricated scaffolds present a platform that can be used for anisotropic tissue engineering applications such as cardiac patches. - Highlights: • Silk/gelatin scaffolds with unidirectional alignment were fabricated using a simple and scalable process • Presence of gelatin in silk resulted to lesser shrinkage, better water retention and improved cell proliferation. • Mesenchymal stem cells were shown to align themselves according to the fiber alignment.

  7. Fabrication and Physical Evaluation of Gelatin-Coated Carbonate Apatite Foam

    Directory of Open Access Journals (Sweden)

    Kanae Hara

    2016-08-01

    Full Text Available Carbonate apatite (CO3Ap foam has gained much attention in recent years because of its ability to rapidly replace bone. However, its mechanical strength is extremely low for clinical use. In this study, to understand the potential of gelatin-reinforced CO3Ap foam for bone replacement, CO3Ap foam was reinforced with gelatin and the resulting physical characteristics were evaluated. The mechanical strength increased significantly with the gelatin reinforcement. The compressive strength of gelatin-free CO3Ap foam was 74 kPa whereas that of the gelatin-reinforced CO3Ap foam, fabricated using 30 mass % gelatin solution, was approximately 3 MPa. Heat treatment for crosslinking gelatin had little effect on the mechanical strength of the foam. The gelatin-reinforced foam did not maintain its shape when immersed in a saline solution as this promoted swelling of the gelatin; however, in the same conditions, the heat-treated gelatin-reinforced foam proved to be stable. It is concluded, therefore, that heat treatment is the key to the fabrication of stable gelatin-reinforced CO3Ap foam.

  8. Gelatin Nanofiber Matrices Derived from Schiff Base Derivative for Tissue Engineering Applications.

    Science.gov (United States)

    Jaiswal, Devina; James, Roshan; Shelke, Namdev B; Harmon, Matthew D; Brown, Justin L; Hussain, Fazle; Kumbar, Sangamesh G

    2015-11-01

    Electrospinning of water-soluble polymers and retaining their mechanical strength and bioactivity remain challenging. Volatile organic solvent soluble polymers and their derivatives are preferred for fabricating electrospun nanofibers. We report the synthesis and characterization of 2-nitrobenzyl-gelatin (N-Gelatin)--a novel gelatin Schiff base derivative--and the resulting electrospun nanofiber matrices. The 2-nitrobenzyl group is a photoactivatable-caged compound and can be cleaved from the gelatin nanofiber matrices following UV exposure. Such hydrophobic modification allowed the fabrication of gelatin and blend nanofibers with poly(caprolactone) (PCL) having significantly improved tensile properties. Neat gelatin and their PCL blend nanofiber matrices showed a modulus of 9.08 ± 1.5 MPa and 27.61 ± 4.3 MPa, respectively while the modified gelatin and their blends showed 15.63 ± 2.8 MPa and 24.47 ± 8.7 MPa, respectively. The characteristic infrared spectroscopy band for gelatin Schiff base derivative at 1560 cm(-1) disappeared following exposure to UV light indicating the regeneration of free NH2 group and gelatin. These nanofiber matrices supported cell attachment and proliferation with a well spread morphology as evidenced through cell proliferation assay and microscopic techniques. Modified gelatin fiber matrices showed a 73% enhanced cell attachment and proliferation rate compared to pure gelatin. This polymer modification methodology may offer a promising way to fabricate electrospun nanofiber matrices using a variety of proteins and peptides without loss of bioactivity and mechanical strength.

  9. Irradiation of gelatin. Important applications for the development of new materials

    Energy Technology Data Exchange (ETDEWEB)

    Del Mastro, N. L., E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05008-900 Sao Paulo (Brazil)

    2011-11-15

    Gelatin is obtained from a naturally occurring protein, collagen, by chemical and thermal hydrolysis. As a protein, gelatin is biodegradable. Among biomaterials, gelatin is an interesting material because the dehydrated gelatin is a partially crystalline polymer and has a relatively low melting point. Gelatin melts to a liquid when heated and solidifies when cooled again. Together with water, it forms a semi-solid colloid gel. If gelatin is placed in contact with cold water, some of the material dissolves, their solubility being determined by their manufacturing method. Ionizing radiation acting on aqueous biological systems produces labile intermediates. Macromolecular free radicals may be diffusion ally mobile in homogenous solutions but relatively immobile in gelled systems. In this paper, different works, some of them performed in our laboratory, are firstly described showing gelatin irradiation in diverse systems. We have already studied the mechanical properties of gelatin composites prepared with a natural fiber, plasticizer and treated by electron beam irradiation. Departing from that, the range of novel applications for gelatin composites like gelatin nanoparticles as biodegradable s and low cell toxic alternative carrier delivery systems are outlined. The potential and the possibilities of using gelatin irradiation for important applications for the development of new materials for medical and food industry are presented. (Author)

  10. Gelatin controversies in food, pharmaceuticals, and personal care products: Authentication methods, current status, and future challenges.

    Science.gov (United States)

    Ali, Eaqub; Sultana, Sharmin; Hamid, Sharifah Bee Abd; Hossain, Motalib; Yehya, Wageeh A; Kader, Abdul; Bhargava, Suresh K

    2016-12-29

    Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.

  11. Two-layer sheet of gelatin: A new topical hemostatic agent.

    Science.gov (United States)

    Takagi, Toshitaka; Tsujimoto, Hiroyuki; Torii, Hiroko; Ozamoto, Yuki; Hagiwara, Akeo

    2016-11-02

    Uncontrolled surgical bleeding is associated with increased morbidity, mortality, and hospital cost. Topical hemostatic agents available today have problems controlling hemostatic effects; furthermore, their handling is difficult and they are unsafe. We devised a new hemostatic agent comprising gelatin sponge and film designed to be applied to the bleeding site, thereby creating a topical hemostatic agent made of gelatin alone. The gelatin was prepared by alkali treatment to eliminate viral activity. Hemostatic effects, surgical handling, and tissue reactions of the materials, namely a two-layer sheet of gelatin, TachoSil, and gelatin sponge, were evaluated using 21 dogs' spleens. The two-layer gelatin sheet and gelatin sponge exhibited superior hemostatic effects (100% hemostasis completed) compared with TachoSil (0-17% hemostasis). The gelatin matrix immediately absorbed blood flowing from wounds and activated the autologous components in the absorbed blood that promoted coagulation at the bleeding site. The two-layer gelatin sheet had the best surgical handling among the evaluated materials. Materials made of gelatin were associated with fewer inflammatory reactions compared with materials of TachoSil. The two-layer sheet of gelatin is a useful topical agent because of its superior hemostatic effects and usability, and is associated with a lower risk of transmitting diseases and inflammatory reactions. Copyright © 2016. Published by Elsevier Taiwan.

  12. Corneal donations in South Africa: A 15-year review.

    Science.gov (United States)

    York, Nicholas J; Tinley, Christopher

    2017-07-28

    Corneal pathology is one of the leading causes of preventable blindness in South Africa (SA). A corneal transplant can restore or significantly improve vision in most cases. However, in SA there is a gross shortage of corneal tissue available to ophthalmologists. Little has been published describing the magnitude of the problem. To describe trends in the number of corneal donors per year in SA, the number of corneal transplants performed each year, the origin of donors, the allocation of corneas to the public or private sector, and the demographics of donors. This was a retrospective review of all corneal donations to SA eye banks over the 15-year period 1 January 2002 - 31 December 2016. There was a progressive year-on-year decline in corneal donors over the study period, from 565 per year in 2002 to 89 in 2016. As a direct result, there has been an 85.5% decrease in the number of corneal transplants performed per year using locally donated corneas, from 1 049 in 2002 to 152 in 2016. Of the donors, 48.8% originated from mortuaries, 39.0% from private hospitals and 12.2% from government hospitals; donors from mortuaries showed the most significant decline over the 15-year period, decreasing by 94.8%. Of donated corneas, 79.3% were allocated to the private sector and 21.7% to the public sector. Males comprised 69.1% of donors, while 77.2% were white, 14.0% coloured, 6.3% black and 2.5% Indian/Asian. Donor age demonstrated a bimodal peak at 25 and 55 years. The number of corneal donations in SA has declined markedly, causing the burden of corneal disease requiring transplantation to rise steadily. Population groups with a low donor rate may have cultural and other objections to corneal donation, which should be a major focus of future research and initiatives aimed at reversing the current trends.

  13. Antioxidant and cryoprotective effects of Amur sturgeon skin gelatin hydrolysate in unwashed fish mince.

    Science.gov (United States)

    Nikoo, Mehdi; Benjakul, Soottawat; Xu, Xueming

    2015-08-15

    Antioxidant and cryoprotective effects of Amur sturgeon skin gelatin hydrolysates prepared using different commercial proteases in unwashed fish mince were investigated. Gelatin hydrolysates prepared using either Alcalase or Flavourzyme, were effective in preventing lipid oxidation as evidenced by the lower thiobarbituric acid-reactive substances formation. Gelatin hydrolysates were able to retard protein oxidation as indicated by the retarded protein carbonyl formation and lower loss in sulfhydryl content. In the presence of gelatin hydrolysates, unwashed mince had higher transition temperature of myosin and higher enthalpy of myosin and actin as determined by differential scanning calorimetry. Based on low field proton nuclear magnetic resonance analysis, gelatin hydrolysates prevented the displacement of water molecules between the different compartments, thus stabilizing the water associated with myofibrils in unwashed mince induced by repeated freeze-thawing. Oligopeptides in gelatin hydrolysates more likely contributed to the cryoprotective effect. Thus, gelatin hydrolysate could act as both antioxidant and cryoprotectant in unwashed fish mince.

  14. UV treatments on the physicochemical properties of tilapia skin and pig skin gelatin.

    Science.gov (United States)

    Wu, C K; Tsai, J S; Chen, Z Y; Sung, W C

    2015-06-01

    Tilapia skin gelatin, pig skin gelatin, and their mousse premixes were exposed to UV irradiation for 103, 206, and 309 kJ/cm(2). All samples after 309 kJ/cm(2) exposure exhibited a significant increase in gel strength, gel forming ability as well as viscosity of solutions. It was shown that UV treatment could also improve the pig skin gelatin foam stability and foam formation ability compared to those of tilapia skin gelatin. Nevertheless, the panelists gave the lowest scores to mousse made with 309 kJ/cm(2) UV-irradiated premix mousse pig skin gelatin. Tilapia skin gelatin could be used as a substitute ingredient for premix mousse made from pig skin gelatin.

  15. In vitro evaluation of crosslinked electrospun fish gelatin scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, S.R. [Centro de Física e Investigação Tecnológica / Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Rodrigues, G.; Martins, G.G. [Centro de Biologia Ambiental / Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, FCUL, 1749-016 Campo Grande, Lisboa (Portugal); Henriques, C.M.R. [Centro de Física e Investigação Tecnológica / Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Silva, J.C., E-mail: jcs@fct.unl.pt [Centro de Física e Investigação Tecnológica / Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2013-04-01

    Gelatin from cold water fish skin was electrospun, crosslinked and investigated as a substrate for the adhesion and proliferation of cells. Gelatin was first dissolved in either water or concentrated acetic acid and both solutions were successfully electrospun. Cross-linking was achieved via three different routes: glutaraldehyde vapor, genipin and dehydrothermal treatment. Solution's properties (surface tension, electrical conductivity and viscosity) and scaffold's properties (chemical bonds, weight loss and fiber diameters) were measured. Cellular viability was analyzed culturing 3T3 fibroblasts plated on the scaffolds and grown up to 7 days. The cells were fixed and observed with SEM or stained for DNA and F-actin and observed with confocal microscopy. In all scaffolds, the cells attached and spread with varying degrees. The evaluation of cell viability showed proliferation of cells until confluence in scaffolds crosslinked by glutaraldehyde and genipin; however the rate of growth in genipin crosslinked scaffolds was slow, recovering only by day five. The results using the dehydrothermal treatment were the less satisfactory. Our results show that glutaraldehyde treated fish gelatin is the most suitable substrate, of the three studied, for fibroblast adhesion and proliferation. - Highlights: ► Electrospinning of fish gelatin dissolved in both water or concentrated acetic acid ► Glutaraldehyde, genipin and dehydrothermal treatment effectively crosslink the fish gelatin fibers ► Fibroblasts effectively adhere to and propagate on all scaffolds ► Cell population is highest for glutaraldehyde crosslinked scaffolds ► Cells exhibit more filopodia and stress fibers on glutaraldehyde crosslinked scaffolds.

  16. Technique to optimize magnetic response of gelatin coated magnetic nanoparticles.

    Science.gov (United States)

    Parikh, Nidhi; Parekh, Kinnari

    2015-07-01

    The paper describes the results of optimization of magnetic response for highly stable bio-functionalize magnetic nanoparticles dispersion. Concentration of gelatin during in situ co-precipitation synthesis was varied from 8, 23 and 48 mg/mL to optimize magnetic properties. This variation results in a change in crystallite size from 10.3 to 7.8 ± 0.1 nm. TEM measurement of G3 sample shows highly crystalline spherical nanoparticles with a mean diameter of 7.2 ± 0.2 nm and diameter distribution (σ) of 0.27. FTIR spectra shows a shift of 22 cm(-1) at C=O stretching with absence of N-H stretching confirming the chemical binding of gelatin on magnetic nanoparticles. The concept of lone pair electron of the amide group explains the mechanism of binding. TGA shows 32.8-25.2% weight loss at 350 °C temperature substantiating decomposition of chemically bind gelatin. The magnetic response shows that for 8 mg/mL concentration of gelatin, the initial susceptibility and saturation magnetization is the maximum. The cytotoxicity of G3 sample was assessed in Normal Rat Kidney Epithelial Cells (NRK Line) by MTT assay. Results show an increase in viability for all concentrations, the indicative probability of a stimulating action of these particles in the nontoxic range. This shows the potential of this technique for biological applications as the coated particles are (i) superparamagnetic (ii) highly stable in physiological media (iii) possibility of attaching other drug with free functional group of gelatin and (iv) non-toxic.

  17. Gelatin functionalised porous titanium alloy implants for orthopaedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Vanderleyden, E. [Polymer Chemistry and Biomaterials Research Group, Department of Organic Chemistry, University of Ghent, Krijgslaan 281 S4, 9000 Ghent (Belgium); Van Bael, S. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Department of Mechanical Engineering, Division of Biomechanics and Engineering Design, Katholieke Universiteit Leuven, Celestijnenlaan 300c, Box 2419, 3001 Heverlee (Belgium); Chai, Y.C. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Tissue Engineering Laboratory, Skeletal Biology and Engineering Research Center, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Kruth, J.-P. [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Schrooten, J. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, Bus 2450, 3001 Leuven (Belgium); Dubruel, P., E-mail: pbmugent@gmail.com [Polymer Chemistry and Biomaterials Research Group, Department of Organic Chemistry, University of Ghent, Krijgslaan 281 S4, 9000 Ghent (Belgium)

    2014-09-01

    In the present work, we studied the immobilisation of the biopolymer gelatin onto the surface of three dimensional (3D) regular Ti6Al4V porous implants to improve their surface bio-activity. The successful immobilisation of the gelatin coating was made possible by a polydopamine interlayer, a polymer coating inspired by the adhesive nature of mussels. The presence of both coatings was first optimised on two dimensional titanium (2D Ti) substrates and confirmed by different techniques including X-ray photelectron spectroscopy, contact angle measurements, atomic force microscopy and fluorescence microscopy. Results showed homogeneous coatings that are stable for at least 24 h in phosphate buffer at 37 °C. In a next step, the coating procedure was successfully transferred to 3D Ti6Al4V porous implants, which indicates the versatility of the applied coating procedure with regard to complex surface morphologies. Furthermore, the bio-activity of these stable gelatin coatings was enhanced by applying a third and final coating using the cell-attractive protein fibronectin. The reproducible immobilisation process allowed for a controlled biomolecule presentation to the surrounding tissue. This newly developed coating procedure outperformed the previously reported silanisation procedure for immobilising gelatin. In vitro cell adhesion and culture studies with human periosteum-derived cells showed that the investigated coatings did not compromise the biocompatible nature of Ti6Al4V porous implants, but no distinct biological differences between the coatings were found. - Highlights: • Ti6Al4V porous implants were produced by selective laser melting. • A procedure to obtain a stable gelatin coating was developed. • Successful transfer of the coating procedure from 2D to 3D Ti6Al4V porous implants. • In vitro cell studies showed that the developed coatings supported cell growth.

  18. Comparison of corneal sensitivity, tear function and corneal staining following laser in situ keratomileusis with two femtosecond laser platforms

    Directory of Open Access Journals (Sweden)

    Petznick A

    2013-03-01

    Full Text Available Andrea Petznick,1 Annabel Chew,2 Reece C Hall,2 Cordelia ML Chan,2 Mohamad Rosman,1,2 Donald Tan,1–3 Louis Tong,1–4 Jodhbir S Mehta1–31Singapore Eye Research Institute, Singapore; 2Singapore National Eye Centre, Singapore; 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 4Duke-NUS Graduate Medical School, SingaporePurpose: To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK using two different femtosecond lasers.Methods: In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT, Schirmer’s test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively.Results: There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05, although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P 0.05.Conclusion: This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.Keywords: femtosecond laser, corneal sensitivity, tear film break-up time, Schirmer’s, corneal staining

  19. Outcome of corneal transplantation: can a prioritisation system predict outcome?

    OpenAIRE

    Saunders, Patrick P R; Sibley, Lyn M; Richards, John S F; Simon P. Holland; Chow, Debbie L; Courtright, Paul

    2002-01-01

    Background: In 1995 a prioritisation system for patients waiting for corneal transplantation surgery was adopted in British Columbia. In 1997 a routine outcome assessment programme was adopted. The authors sought to determine the outcomes of corneal transplant surgery in the province of British Columbia and to evaluate if they were associated with waiting list prioritisation.

  20. Genomics of corneal wound healing: a review of the literature.

    Science.gov (United States)

    Maycock, Nick J R; Marshall, John

    2014-05-01

    Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture.

  1. Applications and advantages of corneal crosslinking for treatment of keratoconus

    NARCIS (Netherlands)

    Soeters, N.

    2015-01-01

    Keratoconus is a corneal disorder in which the cornea becomes cone-shaped due to stromal thinning and corneal weakening. It mainly affects young individuals and although the prevalence is low (1:2000), the impact on quality of life is high. Despite much effort, still no cure has been found for

  2. Applications and advantages of corneal crosslinking for treatment of keratoconus

    NARCIS (Netherlands)

    Soeters, N.

    2015-01-01

    Keratoconus is a corneal disorder in which the cornea becomes cone-shaped due to stromal thinning and corneal weakening. It mainly affects young individuals and although the prevalence is low (1:2000), the impact on quality of life is high. Despite much effort, still no cure has been found for kerat

  3. Effects of genipin corneal crosslinking in rabbit corneas.

    Science.gov (United States)

    Avila, Marcel Y; Narvaez, Mauricio; Castañeda, Juan P

    2016-07-01

    To evaluate the effect of genipin, a natural crosslinking agent, in rabbit eyes. Department of Ophthalmology, Universidad Nacional de Colombia Centro de Tecnologia Oftalmica, Bogotá, Colombia. Experimental study. Ex vivo rabbit eyes (16; 8 rabbits) were treated with genipin 1.00%, 0.50%, and 0.25% for 5 minutes with a vacuum device to increase corneal permeability. Penetration was evaluated using Scheimpflug pachymetry (Pentacam). In the in vivo model (20 rabbits; 1 eye treated, 1 eye with vehicle), corneas were crosslinked with genipin as described. Corneal curvature, corneal pachymetry, and intraocular pressure (IOP) assessments as well as slitlamp examinations were performed 0, 7, 30, and 60 days after treatment. In the ex vivo model, Scheimpflug pachymetry showed deep penetration in the rabbit corneas with an increase in corneal density and a dose-dependent relationship. Corneal flattening was observed in treated eyes (mean 4.4 diopters ± 0.5 [SD]) compared with the control eyes. Pachymetry and IOP were stable in all evaluations. No eye showed toxicity in the anterior chamber or in the lens. Corneal crosslinking induced by genipin produced significant flattening of the cornea with no toxicity in rabbit eyes. This crosslinking could be useful in the treatment of corneal ectasia and in the modification of corneal curvature. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  4. Less Invasive Corneal Transepithelial Electrical Resistance Measurement Method.

    Science.gov (United States)

    Uematsu, Masafumi; Mohamed, Yasser Helmy; Onizuka, Naoko; Ueki, Ryotaro; Inoue, Daisuke; Fujikawa, Azusa; Sasaki, Hitoshi; Kitaoka, Takashi

    2016-01-01

    To evaluate acute corneal permeability changes after instillation of benzalkonium chloride (BAC) using a newly developed in vivo less invasive corneal transepithelial electrical resistance (TER) measurement method in animals and humans. We previously developed an in vivo method for measuring corneal TER using intraocular electrodes in animals. This method can be used to precisely measure the decline of the corneal barrier function after instillation of BAC. To lessen the invasiveness of that procedure, we further refined the method for measuring the corneal TER by developing electrodes that could be placed on the surface of the cornea and in the conjunctival sac instead of inserting them into the anterior chamber. Corneal TER changes before and after exposure to 0.02% BAC were determined in this study using the new device in both rabbits and humans. There was a significant decrease in the corneal TER after exposure of the cornea to 0.02% BAC solution in both rabbits and humans (Pmeasurement method enables us for the first time to measure TER of the human cornea, allowing safe and reliable investigation of the direct effect of different eye drop treatments on the corneal epithelium. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Corneal stem cells and tissue engineering: Current advancesand future perspectives

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Major advances are currently being made in regenerativemedicine for cornea. Stem cell-based therapiesrepresent a novel strategy that may substituteconventional corneal transplantation, albeit there aremany challenges ahead given the singularities of eachcellular layer of the cornea. This review recapitulatesthe current data on corneal epithelial stem cells,corneal stromal stem cells and corneal endothelialcell progenitors. Corneal limbal autografts containingepithelial stem cells have been transplanted in humansfor more than 20 years with great successful rates,and researchers now focus on ex vivo cultures andother cell lineages to transplant to the ocular surface.A small population of cells in the corneal endotheliumwas recently reported to have self-renewal capacity,although they do not proliferate in vivo . Two mainobstacles have hindered endothelial cell transplantationto date culture protocols and cell delivery methods tothe posterior cornea in vivo . Human corneal stromalstem cells have been identified shortly after therecognition of precursors of endothelial cells. Stromalstem cells may have the potential to provide a directcell-based therapeutic approach when injected tocorneal scars. Furthermore, they exhibit the ability todeposit organized connective tissue in vitro and maybe useful in corneal stroma engineering in the future.Recent advances and future perspectives in the field arediscussed.

  6. In Vivo Corneal Biomechanical Properties with Corneal Visualization Scheimpflug Technology in Chinese Population

    Directory of Open Access Journals (Sweden)

    Ying Wu

    2016-01-01

    Full Text Available Purpose. To determine the repeatability of recalculated corneal visualization Scheimpflug technology (CorVis ST parameters and to study the variation of biomechanical properties and their association with demographic and ocular characteristics. Methods. A total of 783 healthy subjects were included in this study. Comprehensive ophthalmological examinations were conducted. The repeatability of the recalculated biomechanical parameters with 90 subjects was assessed by the coefficient of variation (CV and intraclass correlation coefficient (ICC. Univariate and multivariate linear regression models were used to identify demographic and ocular factors. Results. The repeatability of the central corneal thickness (CCT, deformation amplitude (DA, and first/second applanation time (A1/A2-time exhibited excellent repeatability (CV% ≤ 3.312% and ICC ≥ 0.929 for all measurements. The velocity in/out (Vin/out, highest concavity- (HC- radius, peak distance (PD, and DA showed a normal distribution. Univariate linear regression showed a statistically significant correlation between Vin, Vout, DA, PD, and HC-radius and IOP, CCT, and corneal volume, respectively. Multivariate analysis showed that IOP and CCT were negatively correlated with Vin, DA, and PD, while there was a positive correlation between Vout and HC-radius. Conclusion. The ICCs of the recalculated parameters, CCT, DA, A1-time, and A2-time, exhibited excellent repeatability. IOP, CCT, and corneal volume significantly influenced the biomechanical properties of the eye.

  7. Customized toric intraocular lens implantation for correction of extreme corneal astigmatism due to corneal scarring

    Directory of Open Access Journals (Sweden)

    R Bassily

    2010-03-01

    Full Text Available R Bassily, J LuckOphthalmology Department, Royal United Hospital, Combe Park, Bath, UKAbstract: A 76-year-old woman presented with decreased visual function due to cataract formation. Twenty-five years prior she developed right sided corneal ulceration that left her with 10.8 diopters (D of irregular astigmatism at 71.8° (steep axis. Her uncorrected visual acuity was 6/24 and could only ever wear a balanced lens due to the high cylindrical error. Cataract surgery was planned with a custom designed toric intraocular lens (IOL with +16.0 D sphere inserted via a wound at the steep axis of corneal astigmatism. Postoperative refraction was -0.75/+1.50 × 177° with a visual acuity of 6/9 that has remained unchanged at six-week follow-up with no IOL rotation. This case demonstrates the value of high power toric IOLs for the correction of pathological corneal astigmatism.Keywords: intraocular lens, corneal ulceration, visual acuity, scarring

  8. Evidence-based Homoeopathy: A case of corneal abscess

    Directory of Open Access Journals (Sweden)

    Sandeep Sudhakar Sathye

    2016-01-01

    Full Text Available Corneal abscess is a circumscribed collection of pus within the layers of cornea. It is usually endogenous in origin and commonly found near the limbal blood vessels close to corneal margin. Treatment in modern medicine is use of local and systemic antibiotics. Homoeopathy has mentioned medicines for corneal abscess. A case reported was a female of 68 years of age suffering from symptoms of redness, dull pain, and foreign body sensation in the right eye and was diagnosed as corneal abscess. The homoeopathic medicine Hepar sulphuris 200C was prescribed on the basis of pathology. Abscess was reduced considerably within 5 days and it was absorbed completely in 21 days. No recurrence of abscess was observed thereafter. Ocular photographs during follow-up visits have provided documentary evidence about the effectiveness of homoeopathic Hepar sulphuris 200C in corneal abscess.

  9. Paracentral Corneal Dellen:A Rare Sign of Graves Ophthalmopathy

    Institute of Scientific and Technical Information of China (English)

    Jianhua Yan; Zhongyao Wu

    2003-01-01

    Purpose: To report a rare sign, paracentral corneal dellen that developed in a middleaged female patient with Graves ophthalmopathy.Methods:A paracentral corneal dellen developed in the left eye in a 42-year-old woman who was diagnosed as Graves ophthalmopathy. The patient had remarkable upper eyelid retraction, upper eyelid lag and upward motility restriction. The Graves ophthalmopathy was classified as Grade V according to NOSPECS classification.Results:Local artificial tear film and 0.3% Tobramycin eye drops were administered to both eyes.Twenty-four hours later, the left corneal dellen disappeared.Conclusions:Graves ophthalmopathy can lead to paracentral corneal dellen because of severe upper eyelid retraction and upward motility restriction of the eye in spite of the lack of lagophthalmos. Artificial tear drop and antibiotic eye drop therapy helped even though the patient did not have corneal exposure.

  10. Mechanism of Corneal Endothelial Cells Lesion during Phacoemulsification and Aspiration

    Institute of Scientific and Technical Information of China (English)

    Songtao Yuan; Lina Xie; Qinghuai Liu; Nanrong Yuan

    2003-01-01

    Purpose: To evaluate the proportions of corneal endothelial lesion caused by differentfactors during phacoemulsification and aspiration.Methods: Fourteen cats (twenty eight eyes) were divided into four groups. The processedfactors were ultrasonic power, lens extraction by phacoemulsification or not, and lensextraction using different levels of ultrasonic power. The density of central cornealendothelial cells was measured before and after operation.Results: There is no statistic difference between pre-operation density and post-operationdensity for releasing ultrasonic power only without lens extraction group. But for the lensextraction group, there is difference in density of central corneal endothelial cells andthe higher level of ultrasonic power, the more the central corneal endothelial cells densitydecreased through operation.Conclusion: The primary factor that causes corneal endothelial lesion duringphacoemulsification and aspiration procedure is debris of lens nucleus, and the otherfactors cause the lesion of corneal endothelium in normal operations just in very smalldegree.

  11. Biomechanical and morphological corneal response to placement of intrastromal corneal ring segments for keratoconus.

    Science.gov (United States)

    Dauwe, Caroline; Touboul, David; Roberts, Cynthia J; Mahmoud, Ashraf M; Kérautret, Julien; Fournier, Pierre; Malecaze, François; Colin, Joseph

    2009-10-01

    To evaluate the biomechanical and morphological changes in keratoconic corneas after Intacs intrastromal corneal ring segment (ICRS) implantation. Department of Ophthalmology, National Reference Center for Keratoconus, Bordeaux University, Bordeaux, France. Keratoconic eyes were retrospectively analyzed after ICRS implantation; preoperative and 6-month postoperative evaluation were done using the Ocular Response Analyzer (ORA) and the Orbscan II topographer. Biomechanical parameters included corneal hysteresis (CH), the corneal resistance factor (CRF), and other parameters extracted from the signal curves. Morphological parameters included simulated keratometry and the cone location magnitude index from the axial map (aCLMI) and tangential map (tCLMI). Parameters were extracted using software designed to read and process topographic maps. There were no significant differences between preoperatively and postoperatively in mean CH (7.7 mm Hg +/- 1.4 [SD] versus 7.4 +/- 1.4 mm Hg) or mean CRF (6.6 +/- 1.8 mm Hg versus 6.1 +/- 1.4 mm Hg). Only 2 ORA signal parameters were significantly different. Topographic parameters with significant decreases were minimum central keratometry (K) (mean change -5.8 +/- 2.9 diopters [D]) (P<.001), minimum central K (mean change -5.8 +/- 2.3 D) (P<.001), mean aCLMI (9.6 +/- 2.7 preoperatively versus 7.7 +/- 2.5 postoperatively) (P<.009), and mean tCLMI (18.9 +/- 2.8 versus 12.9 +/- 4.4) (P<.002). The only significant correlation between biomechanical and topographic parameters was postoperative ORA infrared signal peak 1 and postoperative aCLMI. Intrastromal corneal ring implantation significantly decreased corneal curvature, with preoperative values predicting magnitude of change. However, it did not alter the viscoelastic biomechanical parameters of CH and CRF.

  12. Corneal confocal microscopy is a rapid reproducible ophthalmic technique for quantifying corneal nerve abnormalities.

    Science.gov (United States)

    Kalteniece, Alise; Ferdousi, Maryam; Adam, Safwaan; Schofield, Jonathan; Azmi, Shazli; Petropoulos, Ioannis; Soran, Handrean; Malik, Rayaz A

    2017-01-01

    To assess the effect of applying a protocol for image selection and the number of images required for adequate quantification of corneal nerve pathology using in vivo corneal confocal microscopy (IVCCM). IVCCM was performed in 35 participants by a single examiner. For each participant, 4 observers used a standardized protocol to select 6 central corneal nerve images to assess the inter-observer variability. Furthermore, images were selected by a single observer on two occasions to assess intra-observer variability and the effect of sample size was assessed by comparing 6 with 12 images. Corneal nerve fiber density (CNFD), branch density (CNBD) and length (CNFL) were quantified using fully automated software. The data were compared using the intra class correlation coefficient (ICC) and Bland-Altman agreement plots for all experiments. The ICC values for CNFD, CNBD and CNFL were 0.93 (P<0.0001), 0.96 (P<0.0001) and 0.95 (P<0.0001) for inter-observer variability and 0.95 (P<0.0001), 0.97 (P<0.001) and 0.97 (P<0.0001) for intra-observer variability. For sample size variability, ICC values were 0.94 (P<0.0001), 0.95 (P<0.0001), and 0.96 (P<0.0001) for CNFD, CNBD and CNFL. Bland-Altman plots showed excellent agreement for all parameters. This study shows that implementing a standardized protocol to select IVCCM images results in high intra and inter-observer reproducibility for all corneal nerve parameters and 6 images are adequate for analysis. IVCCM could therefore be deployed in large multicenter clinical trials with confidence.

  13. Intrastromal corneal ring segments delay corneal grafting in patients with keratoconus

    Directory of Open Access Journals (Sweden)

    Luiz Arthur F. Beniz

    2016-02-01

    Full Text Available ABSTRACT Purpose: To assess the impact of intrastromal corneal ring segments (ICRS as a surgical alternative to corneal grafting in patients with keratoconus who were scheduled for a corneal transplant. Methods: This single-surgeon, single-center, retrospective, observational case series study included 19 eyes of 18 patients (mean age, 23.36 ± 6.22 years with a confirmed diagnosis of keratoconus. These patients were enrolled from the State of Goiás, Brazil corneal graft waiting list. Following extensive pre-operative testing, including the measurement of best-corrected visual acuity (BCVA, applanation tonometry, biomicroscopy, funduscopy, pachymetry, and corneal topography, patients were implanted with Keraring® ICRS. Patients underwent clinical examination at postoperative days 1, 7, 30, 90, and 180 and were examined again 2 years following surgery. Results: At the 2-year cut-off following ICRS implantation (mean follow-up, 28.72 ± 4.71 months, there was a statistically significant improvement in BCVA (logMAR from 0.59 ± 0.35 preoperatively to 0.35 ± 0.45 postoperatively ( p <0.01. Three of 19 eyes (15.8% still required keratoplasty. In the remaining patients (84.2%, BCVA was managed with spectacles (52.6% or contact lenses (31.6%. One patient developed infectious keratitis, requiring removal of ICR at the first postoperative visit. Conclusion: ICRS implantation may be a surgical alternative to keratoplasty in patients with keratoconus. This procedure may delay or even eliminate the need for keratoplasty in such patients.

  14. [Corneal permeability of topically applied pirenzepine solution].

    Science.gov (United States)

    Wang, Kai-di; Zhang, Jin-song; Yan, Pan-shi

    2006-06-01

    To study the corneal permeability of three different pirenzepine eye-drop solutions and provide reference for further clinical use. Sixty-three New Zealand white rabbits were divided into three groups. Each group of rabbits received 2% pirenzepine (pirenzepine group), 2% pirenzepine with 0.1% hyaluronic acid (hyaluronic acid group), or 2% pirenzepine with 0.1% azone (azone group). One drop eye-drops was applied to conjunctive sac every 5 min for six times. Aqueous samples were obtained from each group at 0.5, 1.0, 2.0, 4.0, 8.0, 12.0, 24.0 h after the last drop, respectively. Concentration of pirenzepine in these samples was determined by the HPLC (high pressure liquid chromatography). Stimulation symptom of rabbit eyes was also observed. The concentrations of pirenzepine in aqueous humor were (0.40 +/- 0.06) microg/ml at 0.5 h, (0.53 +/- 0.03) microg/ml at 1.0 h, (1.52 +/- 0.33) microg/ml at 2.0 h and (0.15 +/- 0.02) microg/ml at 4.0 h in pirenzepine group. Aqueous humor concentration of pirenzepine in both 2% pirenzepine with 0.1% azone and 2% pirenzepine with 0.1% hyaluronic acid were significantly higher than that of single pirenzepine application, and their bioavailability in the groups with combinations of pirenzepine with 0.1% azone or 0.1% hyaluronic acid were 23.0 times and 3.4 times higher than that of single pirenzepine usage. No obvious irritate symptom was found in rabbit of all three groups after eye-drop applying. The combination application of pirenzepine with azone or hyaluronic acid has higher corneal permeability compared with pirenzepine alone. This result indicates that azone and hyaluronic acid could be used in pirenzepine eye-drop solution to increase corneal permeability.

  15. Automated Decision Tree Classification of Corneal Shape

    Science.gov (United States)

    Twa, Michael D.; Parthasarathy, Srinivasan; Roberts, Cynthia; Mahmoud, Ashraf M.; Raasch, Thomas W.; Bullimore, Mark A.

    2011-01-01

    Purpose The volume and complexity of data produced during videokeratography examinations present a challenge of interpretation. As a consequence, results are often analyzed qualitatively by subjective pattern recognition or reduced to comparisons of summary indices. We describe the application of decision tree induction, an automated machine learning classification method, to discriminate between normal and keratoconic corneal shapes in an objective and quantitative way. We then compared this method with other known classification methods. Methods The corneal surface was modeled with a seventh-order Zernike polynomial for 132 normal eyes of 92 subjects and 112 eyes of 71 subjects diagnosed with keratoconus. A decision tree classifier was induced using the C4.5 algorithm, and its classification performance was compared with the modified Rabinowitz–McDonnell index, Schwiegerling’s Z3 index (Z3), Keratoconus Prediction Index (KPI), KISA%, and Cone Location and Magnitude Index using recommended classification thresholds for each method. We also evaluated the area under the receiver operator characteristic (ROC) curve for each classification method. Results Our decision tree classifier performed equal to or better than the other classifiers tested: accuracy was 92% and the area under the ROC curve was 0.97. Our decision tree classifier reduced the information needed to distinguish between normal and keratoconus eyes using four of 36 Zernike polynomial coefficients. The four surface features selected as classification attributes by the decision tree method were inferior elevation, greater sagittal depth, oblique toricity, and trefoil. Conclusions Automated decision tree classification of corneal shape through Zernike polynomials is an accurate quantitative method of classification that is interpretable and can be generated from any instrument platform capable of raw elevation data output. This method of pattern classification is extendable to other classification

  16. Mycotic corneal ulcers in upper Assam

    Directory of Open Access Journals (Sweden)

    Reema Nath

    2011-01-01

    Full Text Available Purpose : To study the association of various risk factors and epidemiological variables of mycotic keratitis treated at a tertiary referral hospital of upper Assam. Materials and Methods: In this hospital-based prospective study a total of 310 consecutive corneal ulcer cases attending the ophthalmology outpatient department of Assam Medical College were enrolled between April 2007 and March 2009. After clinical and slit-lamp biomicroscopic examination in all suspected cases, smears and culture examination for fungus was done to establish the etiology. Demographic information and associated probable risk factors of individual cases were noted in a predesigned questionnaire. Results: In 188 (60.6% cases fungal etiology could be established. Out of them 67.6% were males. The most commonly affected age group was 41-50 years (25.5%. The maximum (23.4% cases were reported during the paddy harvesting season in Assam (January and February. Fungal element could be demonstrated in 65.2% cases in direct potassium hydroxide (KOH mount. The commonest predisposing factor was corneal injury (74.5%. While diabetes was a significant systemic predisposing factor in mixed bacterial and fungal infections in 11.1% cases, blocked naso-lacrimal duct was the local predisposing factor in 11.1% of cases. Fusarium solani (25% was the commonest isolate followed by Aspergillus species (19%, Curvularia species (18.5% and Penicillium species (15.2%. Yeasts were isolated in 2.7% (n=5 cases. Conclusions : Ocular trauma was the commonest cause of fungal corneal ulcer in Assam and Fusarium solani was the commonest species responsible for it. Most of the mycotic ulcer cases come from rural areas including the tea gardens.

  17. Fractal dimension based corneal fungal infection diagnosis

    Science.gov (United States)

    Balasubramanian, Madhusudhanan; Perkins, A. Louise; Beuerman, Roger W.; Iyengar, S. Sitharama

    2006-08-01

    We present a fractal measure based pattern classification algorithm for automatic feature extraction and identification of fungus associated with an infection of the cornea of the eye. A white-light confocal microscope image of suspected fungus exhibited locally linear and branching structures. The pixel intensity variation across the width of a fungal element was gaussian. Linear features were extracted using a set of 2D directional matched gaussian-filters. Portions of fungus profiles that were not in the same focal plane appeared relatively blurred. We use gaussian filters of standard deviation slightly larger than the width of a fungus to reduce discontinuities. Cell nuclei of cornea and nerves also exhibited locally linear structure. Cell nuclei were excluded by their relatively shorter lengths. Nerves in the cornea exhibited less branching compared with the fungus. Fractal dimensions of the locally linear features were computed using a box-counting method. A set of corneal images with fungal infection was used to generate class-conditional fractal measure distributions of fungus and nerves. The a priori class-conditional densities were built using an adaptive-mixtures method to reflect the true nature of the feature distributions and improve the classification accuracy. A maximum-likelihood classifier was used to classify the linear features extracted from test corneal images as 'normal' or 'with fungal infiltrates', using the a priori fractal measure distributions. We demonstrate the algorithm on the corneal images with culture-positive fungal infiltrates. The algorithm is fully automatic and will help diagnose fungal keratitis by generating a diagnostic mask of locations of the fungal infiltrates.

  18. Production of Hypoxia-induced Corneal Edema in Aged Eyes

    Institute of Scientific and Technical Information of China (English)

    Alan K. Cheung; Andrew W. Siu; Digby W. Cheung; Edwin C. Mo

    2004-01-01

    Purpose:Corneal thickness assessment is a common clinical procedure applied in corneal and contact lens care. This study aims to investigate the effect of age on hypoxiainduced corneal swelling.Methods:Eighteen male subjects were equally divided into the younger [(23.7±0.8) and older [(74.4±2.5) years old]groups.Each subject wore a thick soft contact lens (uniform thickness of 0.3 mm) on the left cornea. With the contact lens in place, the baseline central corneal thickness was measured using a specially designed photo-pachometer. The lens was then patched behind the closed eyelids, producing an extremely hypoxic stress to the cornea. The change in central corneal thickness was monitored every 20 minutes with momentary disruptions to the hypoxic stress over the next 2 hours. The increase in thickness was taken as an index of corneal edema. The rate of change in corneal thickness, as derived from a non-linear mathematical model, was compared between groups. Results:The corneal thickness of both age groups increased significantly with time (P<0.000 1 ). The mean corneal swelling constant for the older subjects was 16.5 × 10-3 (S.E.M. = 2.65 × 10-3) and the value for the younger subjects was 46.5 × 10-3 (S.E.M. = 3.25× 10-3). The difference was statistically significant (P < 0.000 1 ).Conclusion:Aging cornea has a slower hypoxia-induced edema response compared with the younger group. Whether it is caused by a decreased corneal lactate production or an increased resistance to physical expansion deserves further investigation. Eye Science2004;20:1-5.

  19. Riboflavin concentration in corneal stroma after intracameral injection

    Institute of Scientific and Technical Information of China (English)

    Na; Li; Xiu-Jun; Peng; Zheng-Jun; Fan; Xu; Pang; Yu; Xia; Teng-Fei; Wu

    2015-01-01

    AIM: To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo.METHODS: The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions(BSS)were injected into the anterior chamber(10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5mm in diameter from each group were dissected at 30 min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography(HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24 h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 18.97, 25.08, 20.18, and 1.13 μg/g for 0.5%, 1%, 2%,de-epithelialzed samples, and the transepithelial groups,respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking(CXL) could be achieved by intracameral 1%riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30 min.CONCLUSION: Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL.

  20. Corneal surface reconstruction - a short review

    Directory of Open Access Journals (Sweden)

    Madhavan H N

    2009-01-01

    Full Text Available Cornea is the clear, dome-shaped surface that covers the front of the eye and when damage due to burns or injury and several other diseases, stem cells residing in its rim called "limbus" are stimulated to multiply to support growth of new epithelial cells over its surface. If this ready source of stem cells is damaged or destroyed the natural repair is not possible and such a condition is known as corneal limbal stem cell deficiency (CLSCD disease. Stem cell transplant helps such persons to regenerate the corneal surface. Human corneal limbal stem cell transplantation is at present an established procedure with reasonable good clinical outcome particularly when autologous limbal epithelial tissue from a fellow unaffected eye is used. 1, 2 A major concern related to the autograft is the possibility of CLSCD at the donor site, 3 techniques that allowed the expansion of a small limbal biopsy in the laboratory using cell cultures that could be then transplanted to the affected eye have been developed ,4, 5 Human amniotic membrane (HAM is used as a scaffold for both culturing the human limbal epithelial cells and for ocular surface reconstruction with the cultured limbal epithelial cells. 4-7 However, researchers have used alternative scaffolds like collagen 8, fibrin gel 9 and cross-linked gel of fibronectin and fibrin. 10 All these are biological materials and also need for animal 3T3 feeder layer for stem cell cultures. The properties of HAM are unique including antiadhesive effects, bacteriostatic effects, wound protection, pain reduction, and improvement of epithelialization and characteristically lacking imunogenicity. The use of amniotic membrane transplantation (AMT to treat ocular surface abnormalities was first reported by Graziella Pellegrini, chief of stem cell laboratory at Giovanni Paolo Hospital in Venice, Italy, who was the first to demonstrate the limbal stem cell transplant in 1997. Amniotic membrane has been successfully used in

  1. Graft Biomechanics Following Three Corneal Transplantation Techniques

    Science.gov (United States)

    Feizi, Sepehr; Montahai, Talieh; Moein, Hamidreza

    2015-01-01

    Purpose: To compare corneal biomechanical properties following three different transplantation techniques, including Descemet stripping automated endothelial keratoplasty (DSAEK), deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in comparison to normal eyes. Methods: This cross-sectional comparative study included 118 eyes: 17 eyes of 17 patients received DSAEK, 23 eyes of 21 patients underwent DALK using Anwar's big bubble technique, and 45 eyes of 36 patients had PK; 33 right eyes of 33 normal subjects served as the control group. Using the ocular response analyzer (ORA, Reichert Ophthalmic Instruments, Buffalo, New York, USA), corneal hysteresis (CH) and corneal resistance factor (CRF) were measured and compared among the study groups at least 3 months after all sutures were removed. Results: Mean patient age was 26.9 ± 5.0 years in the control group, 28.8 ± 4.2 in the PK group, 27.2 ± 6.5 in the DALK group, and 62.5 ± 16.8 in the DSAEK group (P < 0.001). Central corneal thickness (CCT) was 539.0 ± 24.8, 567.5 ± 38.8, 547.0 ± 42.6 and 631.1 ± 84.8 μm, respectively (P < 0.001). CH and CRF were significantly lower in the DSAEK group (7.79 ± 2.0 and 7.88 ± 1.74 mmHg, respectively) as compared to the PK (10.23 ± 2.07 and 10.13 ± 2.22 mmHg, respectively) and DALK (9.64 ± 2.07 and 9.36 ± 2.09 mmHg, respectively) groups. The two latter groups demonstrated biomechanical parameters comparable to normal subjects (9.84 ± 1.59 and 9.89 ± 1.73 mmHg, respectively). Conclusion: Graft biomechanical parameters after DSAEK are lower than those following PK and DALK. After PK and DALK in keratoconic eyes, these metrics are increased to normal values. These differences may have implications for interpreting intraocular pressure or planning graft refractive surgery after keratoplasty. PMID:26730307

  2. Radiation stability and modification of gelatin for biological and medical applications

    Science.gov (United States)

    Haema, Kamonwon; Oyama, Tomoko Gowa; Kimura, Atsushi; Taguchi, Mitsumasa

    2014-10-01

    Gelatin is used in various biological and medical fields, including drug delivery systems and tissue engineering. In the context of these applications, radiation sterilization of gelatin was evaluated in terms of radiation stability. The molecular weight of gelatin powder irradiated by electron beams (EB) was analyzed using gel permeation chromatography (GPC). We found that irradiation decomposed the gelatin and that the weight-averaged molar mass (Mw) decreased by approximately 7-10% with sterilization doses in the range of 5-25 kGy. Also, we found that the hydrolysis rate in body and cell culture environments (37 °C water) was affected by irradiation. Although gelatin powder underwent chain scission when irradiated, crosslinking was predominantly induced when the gelatin was irradiated in water solution. Radiation-crosslinked (RX) gelatin hydrogel was fabricated without using any crosslinkers. In this case, fabrication and radiation sterilization were performed simultaneously. Using gel fraction and GPC analysis of the eluted sol, it was determined that the RX-gelatin hydrogel was stable for 7 days in water at 37 °C. These results provide important data for evaluating the feasibility of biological and medical applications of gelatin and RX-gelatin hydrogel.

  3. Characteristics and Gel Properties of Gelatin from Goat Skin as Influenced by Alkaline-pretreatment Conditions

    Directory of Open Access Journals (Sweden)

    Sulaiman Mad-Ali

    2016-06-01

    Full Text Available Characteristics and properties of gelatin from goat skin pretreated with NaOH solutions (0.50 and 0.75 M for various times (1 to 4 days were investigated. All gelatins contained α-chains as the predominant component, followed by β-chain. Gelling and melting temperatures of those gelatins were 23.02°C to 24.16°C and 33.07°C to 34.51°C, respectively. Gel strength of gelatins increased as NaOH concentration and pretreatment time increased (p<0.05. Pretreatment for a longer time yielded gelatin with a decrease in L*-value but an increase in b*-value. Pretreatment of goat skin using 0.75 M NaOH for 2 days rendered the highest yield (15.95%, wet weight basis as well as high gel strength (222.42 g, which was higher than bovine gelatin (199.15 g. Gelatin obtained had the imino acid content of 226 residues/1,000 residues and the gelatin gel had a fine and ordered structure. Therefore, goat skin gelatin could be used as a potential replacer of commercial gelatin.

  4. CHARACTERISTICS OF GELATIN FROM SWIM BLADDER OF YELLOWFIN TUNA (THUNNUS ALBACORES AS INFLUENCED BY EXTRACTING TEMPERATURES

    Directory of Open Access Journals (Sweden)

    O. Kaewdang

    2015-09-01

    Full Text Available Gelatin was extracted from the swim bladder of yellowfin tuna (Thunnus albacores at different temperatures (60, 70 and 80°C with the extraction yields of 35.6%, 41.1% and 47.3% (dryweight basis, respectively. The α-chains of gelatin decreased with increasing extraction temperatures.Similar amino acid compositions were noticeable among all gelatins, in which glycine constituted the major amino acid. Imino acids ranged from 169 to 172 residues/1,000 residues. Thegel strength of gelatin extracted at lower temperature was higher than that of gelatins extracted at higher temperatures. Gelling and melting temperatures for swim bladder gelatin were 11.07-15.24 and 20.36-22.33°C, respectively. Higher gelling and melting points were observed for gelatin extracted at lower temperatures. Microstructure of gel of gelatin extracted at 60°C was finerwith smaller voids, compared with others. FTIR spectra of obtained gelatins revealed the significant loss of molecular order of the triple-helix. Thus, extraction temperatures showed the directimpact on characteristics of gelatin from swim bladder.

  5. Incorporation of Ag metallic nanoparticles in 3D gelatin matrix via the green strategy solution plasma.

    Science.gov (United States)

    Pootawang, Panuphong; Kim, Seong Cheol; Kim, Jung Wan; Lee, Sang Yul

    2013-01-01

    The environmental concern pays much attention to the recent cause of the global warming effect. The reduction of the chemical uses is one of many ways to avoid this crucial problem. Herein, the green process for silver nanometallic particle formation and incorporation in gelatin are proposed. By using a novel discharge process in solution named solution plasma, the silver nanometallic particle formation and its incorporation in gelatin could be accomplished in one-batch reactor during discharge by using silver nitrate (AgNO3) solution as the precursor and controlling systematical parameters. The three-dimensional scaffolds of gelatin/silver biocomposite were fabricated using lyophilizer and the water-soluble property of gelatin was improved by irradiation of ultraviolet ray. The well dispersed silver nanoparticles with the mean particle size 10-20 nm in the good texture of gelatin matrix were obtained. The density of micropore in gelatin/silver scaffold was proportional to the gelatin concentration. In addition, thermal stability of prepared samples had no change comparing with pure gelatin, indicating that the incorporation of silver nanoparticles in gelatin matrix did not affect to the nature of gelatin.

  6. Acute corneal hydrops during pregnancy with spontaneous resolution after corneal cross-linking for keratoconus: a case report.

    Science.gov (United States)

    Stock, Ricardo Alexandre; Thumé, Thaís; Bonamigo, Elcio Luiz

    2017-02-25

    Keratoconus may progress to acute corneal hydrops even after cross-linking. In some cases, keratoconus progresses during pregnancy. In this report, we present a case of a patient with increased anterior stromal resistance after cross-linking that would favor nonprogression of keratoconus during pregnancy. We report that cross-linking is likely to have had a protective effect in a white pregnant patient with acute corneal hydrops who showed rapid improvement, as documented by corneal topography. Improvement occurred within 8 days, whereas up to 250 days are reported in the literature. No keratoconus progression occurred in the 20-month follow-up period. Cross-linking failed to prevent the occurrence of acute corneal hydrops after rupture of Descemet's membrane but most likely helped to accelerate the resolution of the condition. Corneal hardening resulting from cross-linking may have also contributed to stabilizing keratoconus during pregnancy.

  7. How safe is gelatin? A systematic review and meta-analysis of gelatin-containing plasma expanders vs crystalloids and albumin.

    Science.gov (United States)

    Moeller, Claudia; Fleischmann, Carolin; Thomas-Rueddel, Daniel; Vlasakov, Vlasislav; Rochwerg, Bram; Theurer, Philip; Gattinoni, Luciano; Reinhart, Konrad; Hartog, Christiane S

    2016-10-01

    Gelatin is a widely used synthetic colloid resuscitation fluid. We undertook a systematic review and meta-analysis of adverse effects in randomized and nonrandomized studies comparing gelatin with crystalloid or albumin for treatment of hypovolemia. Multiple databases were searched systematically without language restrictions until August 2015. We assessed risk of bias of individual studies and certainty in evidence assessment by the Grading of Recommendations Assessment, Development, and Evaluation approach. Sixty studies were eligible, including 30 randomized controlled trials, 8 nonrandomized studies, and 22 animal studies. After gelatin administration, the risk ratios were 1.15 (95% confidence interval, 0.96-1.38) for mortality, 1.10 (0.86-1.41) for requiring allogeneic blood transfusion, 1.35 (0.58-3.14) for acute kidney injury, and 3.01 (1.27-7.14) for anaphylaxis. Well-performed nonrandomized trials found increased rates of hospital mortality and acute kidney injury or renal replacement therapy in the gelatin intervention periods. Between 17% and 31% of administered gelatin was taken up extravascularly. The mean crystalloid-to-colloid ratio was 1.4. Gelatin solutions increase the risk of anaphylaxis and may be harmful by increasing mortality, renal failure, and bleeding possibly due to extravascular uptake and coagulation impairment. Until well-designed randomized controlled trials show that gelatin is safe, we caution against the use of gelatins because cheaper and safer fluid alternatives are available. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The heritability of glaucoma-related traits corneal hysteresis, central corneal thickness, intraocular pressure, and choroidal blood flow pulsatility.

    Directory of Open Access Journals (Sweden)

    Ellen E Freeman

    Full Text Available PURPOSE: The purpose of this work was to investigate the heritability of potential glaucoma endophenotypes. We estimated for the first time the heritability of the pulsatility of choroidal blood flow. We also sought to confirm the heritability of corneal hysteresis, central corneal thickness, and 3 ways of measuring intraocular pressure. METHODS: Measurements were performed on 96 first-degree relatives recruited from Maisonneuve-Rosemont Hospital in Montreal. Corneal hysteresis was determined using the Reichert Ocular Response Analyser. Central corneal thickness was measured with an ultrasound pachymeter. Three measures of intraocular pressure were obtained: Goldmann-correlated and corneal compensated intraocular pressure using the Ocular Response Analyser, and Pascal intraocular pressure using the Pascal Dynamic Contour Tonometer. The pulsatility of choroidal blood velocity and flow were measured in the sub-foveolar choroid using single-point laser Doppler flowmetry (Oculix. We estimated heritability using maximum-likelihood variance components methods implemented in the SOLAR software. RESULTS: No significant heritability was detected for the pulsatility of choroidal blood flow or velocity. The Goldman-correlated, corneal compensated, and Pascal measures of intraocular pressure measures were all significantly heritable at 0.94, 0.79, and 0.53 after age and sex adjustment (p = 0.0003, p = 0.0023, p = 0.0239. Central corneal thickness was significantly heritable at 0.68 (p = 0.0078. Corneal hysteresis was highly heritable but the estimate was at the upper boundary of 1.00 preventing us from giving a precise estimate. CONCLUSION: Corneal hysteresis, central corneal thickness, and intraocular pressure are all heritable and may be suitable as glaucoma endophenotypes. The pulsatility of choroidal blood flow and blood velocity were not significantly heritable in this sample.

  9. Reagent-free crosslinking of aqueous gelatin: manufacture and characteristics of gelatin gels irradiated with gamma-ray and electron beam.

    Science.gov (United States)

    Terao, Ken; Nagasawa, Naotsugu; Nishida, Hirokazu; Furusawa, Kazuya; Mori, Yasutaka; Yoshii, Fumio; Dobashi, Toshiaki

    2003-01-01

    In order to obtain a gelatin hydrogel crosslinked by a reagent-free method, gamma-ray and electron beam radiation was applied to porcine, bovine and fish gelatin gels and the products were characterized by measuring the gel fraction, the swelling ratio and the enzymatic degradability. On increasing the radiation dose, the gel fraction increased and both the swelling ratio and the enzymatic degradability decreased. The transition temperature from gel to sol of the hydrogel containing more than 5% mammal gelatins increased up to more than 90 degrees C when gamma-ray or electron beam were irradiated by more than 10 kGy. The results show that the degree of crosslinking of irradiated gelatin hydrogels increases with increasing irradiation dose and with decreasing concentration. It is suggested that the radiation crosslinking occurs around the physical crosslinking point or multiple helix structure of gelatin gel.

  10. Gelatin films plasticized with a simulated biodiesel coproduct stream

    Directory of Open Access Journals (Sweden)

    2009-04-01

    Full Text Available In order to explore the possibility of substituting an unrefined biodiesel coproduct stream (BCS for refined glycerol as a polymer plasticizer we have prepared cast gelatin films plasticized with a simulated BCS, i.e., mixtures of glycerol and some of the typical components found in BCS (methyl linoleate, methyl oleate, linoleic acid, and oleic acid. We measured the tensile properties as a function of plasticizer composition, and analyzed the specific effect of each individual component on tensile properties. We found that it is the unrecovered alkyl esters that largely determine the tensile properties, and that BCS can be successfully used to plasticize cast gelatin films as long as the BCS contains 11 parts by weight, or less, of unrecovered alkyl esters per 100 parts glycerol.

  11. In situ observation of crystallinity disruption patterns during starch gelatinization.

    Science.gov (United States)

    Cai, Canhui; Wei, Cunxu

    2013-01-30

    Twelve starches were isolated from the tuberous root of sweet potato, the rhizomes of lotus and yam, the tuber of potato, the corm of water chestnut, and the seeds of pea, bean, barley, wheat, lotus, water caltrop, and ginkgo. Their gelatinization processes were in situ viewed using a polarizing microscope in combination with a hot stage. Four patterns of crystallinity disruption during heating were proposed. The crystallinity disruption initially occurred on the proximal surface of the eccentric hilum, on the distal surface of the eccentric hilum, from the central hilum, or on the surface of the central hilum starch granule. The patterns of initial disruption on the distal surface of the eccentric hilum and on the surface of the central hilum starch were reported for the first time. The heterogeneous distribution of amylose in starch granule might partly explain the different patterns of crystallinity disruption and swelling during gelatinization. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Encapsulation of cationic peptides into polymersomes through in situ gelatinization.

    Science.gov (United States)

    Gao, Huile; Pang, Zhiqing; Lu, Wei; Pan, Shuaiqi; Jiang, Xinguo

    2011-01-01

    Encapsulation of peptides and proteins remains an obstacle in drug nanoformulations. Here, we established an alternative method to encapsulate peptides and proteins into polymersomes (POs). NC-1900, a type of cationic peptide that can induce the gelatinization of deacetylated gellan gum (DGG), was selected as a model peptide. DGG was first trapped in POs to serve as a reservoir to capture NC-1900. Analysis of the optimized formulation revealed that the drug-loading capability of NC-1900-loaded POs was 1.20%, and the encapsulation efficiency was 30%. The release of NC-1900 from the gel was the rate-limiting step and could be expressed by Fick's law of diffusion. These results indicated that the preparation of POs encapsulated with gelatin could be employed as an effective loading method for ionic peptides and proteins.

  13. Ballistic gelatin as a putative substrate for EEG phantom devices

    CERN Document Server

    Hairston, W David; Yu, Alfred B

    2016-01-01

    Phantom devices allow the human variable to be controlled for in order to allow clear comparison and validation of biomedical imaging hardware and software. There is currently no standard phantom for electroencephalography (EEG). To be useful, such a device would need to: (a) accurately recreate the real and imaginary components of scalp electrical impedance, (b) contain internal emitters to create electrical dipoles, and (c) be easily replicable across various labs and research groups. Cost-effective materials, which are conductive, repeatable, and easily formed are a missing key enabler for EEG phantoms. Here, we explore the use of ballistics gelatin, an inexpensive, easily-formable and repeatable material, as a putative substrate by examining its electrical properties and physical stability over time. We show that varied concentrations of NaCl salt relative to gelatin powder shifts the phase/frequency response profile, allowing for selective tuning of the material electrical properties.

  14. Heterogeneities in gelatin film formation using single-sided NMR.

    Science.gov (United States)

    Ghoshal, Sushanta; Mattea, Carlos; Denner, Paul; Stapf, Siegfried

    2010-12-16

    Gelatin solutions were prepared in D(2)O. The drying process of cast solutions was followed with a single-sided nuclear magnetic resonance (NMR) scanner until complete solidification occurred. Spin-spin relaxation times (T(2)) were measured at different layers with microscopic resolution and were correlated with the drying process during film formation. Additionally, the evaporation of the gelatin solution was observed optically from the reduction of the sample thickness, revealing that at the macroscopic level, the rate of evaporation is not uniform throughout the experiment. A crossover in the spatial evolution of the drying process is observed from the NMR results. At the early stages, the gel appears to be drier in the upper layers near the evaporation front, while this tendency is inverted at the later stages, when drying is faster from the bottom. XRD (X-ray diffraction) data showed that a structural heterogeneity persists in the final film.

  15. [New stimulants of corneal reparative regeneration].

    Science.gov (United States)

    Egorov, E A; Kalinin, N I; Kiiasov, A P

    1999-01-01

    The efficacy of corneregel, a drug containing pantothenic acid, a component of coenzyme A, in healing of corneal wounds has been evaluated. The study was carried out on 19 rabbits (38 eyes) with standard corneal defect made with a 5-mm trephine for lamellar transplantation of the cornea, divided into 2 groups: 1) instillations of corneregel (10 eyes) and 0.25% levomycetin solution (10 eyes) and 2) 20% solcoseryl gel (9 eyes) and 0.25% levomycetin (9 eyes). Time course of changes were evaluated by biomicroscopy (fluorescent test), histologically (hematoxylin-eosin staining), and immunohistochemically after 1, 2, 4, 7, 30, and 90 days. Proliferative activity was studied by expression of the proliferating cell nuclear antigen and the migration capacity of cells by expression of alpha-smooth muscle actin. The terms of epithelialization were as follows: corneregel 10 +/- 7 h, 20% solcoseryl gel 108 +/- 10 h, levomycetin 124 +/- 6.93 h. Earlier epithelialization in the corneregel group was apparently due to increased expression of alpha-smooth muscle actin and increase in the cell migration capacity. Hence, corneregel is recommended for practical use as a stimulant of reparative regeneration of the cornea.

  16. Bilateral Keratectasia 34 Years after Corneal Transplant

    Directory of Open Access Journals (Sweden)

    Xavier Valldeperas

    2010-07-01

    Full Text Available We report the clinical findings of a patient with severe bilateral keratectasia 34 years after a penetrating keratoplasty (PK in both eyes. An otherwise healthy 67-year-old man complained of deterioration of the eyesight in both eyes over the last 6 months. The patient was diagnosed with bilateral keratoconus at the age of 32 years, and he underwent a bilateral PK. At presentation, visual acuity was 20/200 in the right eye and light perception in the left eye. A Pentacam pachymetric map revealed a central pachymetry of 720 µm in the right eye and of 710 µm in the left eye, as well as an average paracentral pachymetry of 436 and 270 µm in the 9-mm zone in the right and the left eye, respectively. Corneal topography revealed bilateral irregular and asymmetric bowing with generalized steepening and high corneal power. We describe a case of bilateral keratectasia 34 years after PK in a patient who was originally diagnosed with bilateral keratoconus.

  17. Femtosecond laser's application in the corneal surgery

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    Shu-Liang Wang

    2015-10-01

    Full Text Available With the rapid development over the past two decades,femtosecond(10-15slasers(FShas become a new application in ophthalmic surgery. As laser power is defined as energy delivered per unit time, decreasing the pulse duration to femtosecond level(100fsnot only increases the power delivered but also decreases the fluence threshold for laser induced optical breakdown. In ablating tissue, FS has an edge over nanosecond lasers as there is minimal collateral damage from shock waves and heat conduction during surgical ablation. Thus, application of FS has been widely spread, from flap creation for laser-assisted in situ keratomileusis(LASIKsurgery, cutting of donor and recipient corneas in keratoplasty, creation of pockets for intracorneal ring implantation. FS applied in keratoplasty is mainly used in making graft and recipient bed, and can exactly cut different tissue of keratopathy. FS can also cut partial tissue of cornea, even if it is under the moderate corneal macula and corneal edema condition.

  18. IOL Power Calculation after Corneal Refractive Surgery

    Directory of Open Access Journals (Sweden)

    Maddalena De Bernardo

    2014-01-01

    Full Text Available Purpose. To describe the different formulas that try to overcome the problem of calculating the intraocular lens (IOL power in patients that underwent corneal refractive surgery (CRS. Methods. A Pubmed literature search review of all published articles, on keyword associated with IOL power calculation and corneal refractive surgery, as well as the reference lists of retrieved articles, was performed. Results. A total of 33 peer reviewed articles dealing with methods that try to overcome the problem of calculating the IOL power in patients that underwent CRS were found. According to the information needed to try to overcome this problem, the methods were divided in two main categories: 18 methods were based on the knowledge of the patient clinical history and 15 methods that do not require such knowledge. The first group was further divided into five subgroups based on the parameters needed to make such calculation. Conclusion. In the light of our findings, to avoid postoperative nasty surprises, we suggest using only those methods that have shown good results in a large number of patients, possibly by averaging the results obtained with these methods.

  19. Clinical utility of the KAMRA corneal inlay.

    Science.gov (United States)

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient's visual function.

  20. PLGA Microspheres Incorporated Gelatin Scaffold: Microspheres Modulate Scaffold Properties

    OpenAIRE

    Indranil Banerjee; Debasish Mishra; Maiti, Tapas K.

    2009-01-01

    Freeze drying is one of the popular methods of fabrication for poly(lactide-co-glycolide) (PLGA) microspheres incorporated polymer scaffolds. However, the consequence of microspheres incorporation on physical and biological properties of scaffold has not been studied yet. In this study, attempt has been made to characterize the effect of PLGA microsphere incorporation on the physical properties of freeze-dried gelatin scaffold and its influence on cytocompatibility. Scaffolds loaded with va...

  1. Effects Of Gelatine-Coated Vascular Grafts On Human Neutrophils

    Directory of Open Access Journals (Sweden)

    Meyer Frank

    2015-09-01

    Full Text Available The aim of the study was to investigate the immune-modulatory potential of commercially available PTFE and polyester vascular grafts with and without gelatine-coating. The biomaterial-cell-interaction was characterized by changes of established parameters such as PMN-related receptors/mediators, phagocytosis potential and capacity as well as the effect of an additional plasma-dependent modulation.

  2. Gelatin methacrylate microspheres for controlled growth factor release.

    Science.gov (United States)

    Nguyen, Anh H; McKinney, Jay; Miller, Tobias; Bongiorno, Tom; McDevitt, Todd C

    2015-02-01

    Gelatin has been commonly used as a delivery vehicle for various biomolecules for tissue engineering and regenerative medicine applications due to its simple fabrication methods, inherent electrostatic binding properties, and proteolytic degradability. Compared to traditional chemical cross-linking methods, such as the use of glutaraldehyde (GA), methacrylate modification of gelatin offers an alternative method to better control the extent of hydrogel cross-linking. Here we examined the physical properties and growth factor delivery of gelatin methacrylate (GMA) microparticles (MPs) formulated with a wide range of different cross-linking densities (15-90%). Less methacrylated MPs had decreased elastic moduli and larger mesh sizes compared to GA MPs, with increasing methacrylation correlating to greater moduli and smaller mesh sizes. As expected, an inverse correlation between microparticle cross-linking density and degradation was observed, with the lowest cross-linked GMA MPs degrading at the fastest rate, comparable to GA MPs. Interestingly, GMA MPs at lower cross-linking densities could be loaded with up to a 10-fold higher relative amount of growth factor than conventional GA cross-linked MPs, despite the GA MPs having an order of magnitude greater gelatin content. Moreover, a reduced GMA cross-linking density resulted in more complete release of bone morphogenic protein 4 and basic fibroblast growth factor and accelerated release rate with collagenase treatment. These studies demonstrate that GMA MPs provide a more flexible platform for growth factor delivery by enhancing the relative binding capacity and permitting proteolytic degradation tunability, thereby offering a more potent controlled release system for growth factor delivery.

  3. Preparation and characterization of gelatin/cerium(Ⅲ) film

    Institute of Scientific and Technical Information of China (English)

    黄崇军; 黄雅钦; 田娜; 童元建; 殷瑞贤

    2010-01-01

    A novel gelatin film with antibacterial activity was prepared by electrostatic crosslinking using cerium (Ⅲ) nitrate hexahydrate as the crosslinking agent. The structure and properties of the films were investigated by Fourier transform infrared spectra, tensile tests, thermogravimetric analysis, static drop contact angle and disc diffusion method. The results showed that cross-linking could not only improve the thermal and mechanical properties and lower the hydrophilic property of the films, but also make...

  4. Gelatin as a new humidity sensing material: Characterization and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Shapardanis, Steven [School of Engineering and Technology, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States); Hudpeth, Mathew [Department of Physics, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States); Kaya, Tolga, E-mail: kaya2t@cmich.edu [School of Engineering and Technology, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States); Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States)

    2014-12-15

    The goal of this work is to assert the utility of collagen and its denatured counterpart gelatin as cost-effective alternatives to existing sensing layers comprised of polymers. Rather than producing a material that will need to be discarded or recycled, collagen, as a by-product of the meat and leather industry, could be repurposed. This work examines the feasibility of using collagen as a sensing layer. Planar electrodes were patterned with lift-off process to work with the natural characteristics of gelatin by utilizing metal vapor deposition, spin coating, and photolithography. Characterization methods have also been optimized through the creation of specialized humidity chambers that isolate specific characteristics such as response time, accuracy, and hysteresis. Collagen-based sensors are found to have a sensitivity to moisture in the range of 0.065 pF/%RH. Diffusion characteristics were also analyzed with the diffusion coefficient found to be 2.5 × 10{sup −5} cm{sup 2}/s. Absorption and desorption times were found to be 20 seconds and 8 seconds, respectively. Hysteresis present in the data is attributed to temperature cross-sensitivity. Ultimately, the utility of collagen as a dielectric sensing material is, in part, due to its fibrous macrostructures as well its hydrophilic sites along the peptide chains. Gelatin was patterned between and below interdigitated copper electrodes and tested as a relative humidity sensor. This work shows that gelatin, which is inexpensive, widely available, and easy to process, can be an effective dielectric sensing polymer for capacitive-type relative humidity sensors.

  5. Gelatin as a new humidity sensing material: Characterization and limitations

    Directory of Open Access Journals (Sweden)

    Steven Shapardanis

    2014-12-01

    Full Text Available The goal of this work is to assert the utility of collagen and its denatured counterpart gelatin as cost-effective alternatives to existing sensing layers comprised of polymers. Rather than producing a material that will need to be discarded or recycled, collagen, as a by-product of the meat and leather industry, could be repurposed. This work examines the feasibility of using collagen as a sensing layer. Planar electrodes were patterned with lift-off process to work with the natural characteristics of gelatin by utilizing metal vapor deposition, spin coating, and photolithography. Characterization methods have also been optimized through the creation of specialized humidity chambers that isolate specific characteristics such as response time, accuracy, and hysteresis. Collagen-based sensors are found to have a sensitivity to moisture in the range of 0.065 pF/%RH. Diffusion characteristics were also analyzed with the diffusion coefficient found to be 2.5 × 10−5 cm2/s. Absorption and desorption times were found to be 20 seconds and 8 seconds, respectively. Hysteresis present in the data is attributed to temperature cross-sensitivity. Ultimately, the utility of collagen as a dielectric sensing material is, in part, due to its fibrous macrostructures as well its hydrophilic sites along the peptide chains. Gelatin was patterned between and below interdigitated copper electrodes and tested as a relative humidity sensor. This work shows that gelatin, which is inexpensive, widely available, and easy to process, can be an effective dielectric sensing polymer for capacitive-type relative humidity sensors.

  6. Gelatin as a new humidity sensing material: Characterization and limitations

    Science.gov (United States)

    Shapardanis, Steven; Hudpeth, Mathew; Kaya, Tolga

    2014-12-01

    The goal of this work is to assert the utility of collagen and its denatured counterpart gelatin as cost-effective alternatives to existing sensing layers comprised of polymers. Rather than producing a material that will need to be discarded or recycled, collagen, as a by-product of the meat and leather industry, could be repurposed. This work examines the feasibility of using collagen as a sensing layer. Planar electrodes were patterned with lift-off process to work with the natural characteristics of gelatin by utilizing metal vapor deposition, spin coating, and photolithography. Characterization methods have also been optimized through the creation of specialized humidity chambers that isolate specific characteristics such as response time, accuracy, and hysteresis. Collagen-based sensors are found to have a sensitivity to moisture in the range of 0.065 pF/%RH. Diffusion characteristics were also analyzed with the diffusion coefficient found to be 2.5 × 10-5 cm2/s. Absorption and desorption times were found to be 20 seconds and 8 seconds, respectively. Hysteresis present in the data is attributed to temperature cross-sensitivity. Ultimately, the utility of collagen as a dielectric sensing material is, in part, due to its fibrous macrostructures as well its hydrophilic sites along the peptide chains. Gelatin was patterned between and below interdigitated copper electrodes and tested as a relative humidity sensor. This work shows that gelatin, which is inexpensive, widely available, and easy to process, can be an effective dielectric sensing polymer for capacitive-type relative humidity sensors.

  7. Gellan gum microgel-reinforced cell-laden gelatin hydrogels

    OpenAIRE

    Shin, Hyeongho; Olsen, Bradley D.; Khademhosseini, Ali

    2013-01-01

    The relatively weak mechanical properties of hydrogels remain a major drawback for their application as load-bearing tissue scaffolds. Previously, we developed cell-laden double-network (DN) hydrogels that were composed of photocrosslinkable gellan gum (GG) and gelatin. Further research into the materials as tissue scaffolds determined that the strength of the DN hydrogels decreased when they were prepared at cell-compatible conditions, and the encapsulated cells in the DN hydrogels did not f...

  8. Corneal power evaluation after myopic corneal refractive surgery using artificial neural networks.

    Science.gov (United States)

    Koprowski, Robert; Lanza, Michele; Irregolare, Carlo

    2016-11-15

    Efficacy and high availability of surgery techniques for refractive defect correction increase the number of patients who undergo to this type of surgery. Regardless of that, with increasing age, more and more patients must undergo cataract surgery. Accurate evaluation of corneal power is an extremely important element affecting the precision of intraocular lens (IOL) power calculation and errors in this procedure could affect quality of life of patients and satisfaction with the service provided. The available device able to measure corneal power have been tested to be not reliable after myopic refractive surgery. Artificial neural networks with error backpropagation and one hidden layer were proposed for corneal power prediction. The article analysed the features acquired from the Pentacam HR tomograph, which was necessary to measure the corneal power. Additionally, several billion iterations of artificial neural networks were conducted for several hundred simulations of different network configurations and different features derived from the Pentacam HR. The analysis was performed on a PC with Intel(®) Xeon(®) X5680 3.33 GHz CPU in Matlab(®) Version 7.11.0.584 (R2010b) with Signal Processing Toolbox Version 7.1 (R2010b), Neural Network Toolbox 7.0 (R2010b) and Statistics Toolbox (R2010b). A total corneal power prediction error was obtained for 172 patients (113 patients forming the training set and 59 patients in the test set) with an average age of 32 ± 9.4 years, including 67% of men. The error was at an average level of 0.16 ± 0.14 diopters and its maximum value did not exceed 0.75 dioptres. The Pentacam parameters (measurement results) providing the above result are tangential anterial/posterior. The corneal net power and equivalent k-reading power. The analysis time for a single patient (a single eye) did not exceed 0.1 s, whereas the time of network training was about 3 s for 1000 iterations (the number of neurons in the hidden layer was 400).

  9. Cosmetic textiles with biological benefits: gelatin microcapsules containing vitamin C.

    Science.gov (United States)

    Cheng, Shuk Yan; Yuen, Marcus Chun Wah; Kan, Chi Wai; Cheuk, Kevin Ka Leung; Chui, Chung Hin; Lam, Kim Hung

    2009-10-01

    In recent years, textile materials with special applications in the cosmetic field have been developed. A new sector of cosmetic textiles is opened up and several cosmetic textile products are currently available in the market. Microencapsulation technology is an effective technique to control the release properties of active ingredients that prolong the functionality of cosmetic textiles. This study discusses the development of cosmetic textiles and addresses microencapsulation technology with respect to its historical background, significant advantages, microencapsulation methods and recent applications in the textile industry. Gelatin microcapsules containing vitamin C were prepared using emulsion hardening technique. Both the optical microscopy and scanning electron microscopy demonstrated that the newly developed microcapsules were in the form of core-shell spheres with relatively smooth surface. The particle size of microcapsules ranged from 5.0 to 44.1 microm with the average particle size being 24.6 microm. The gelatin microcapsules were proved to be non-cytotoxic based on the research findings of the toxicity studies conducted on human liver and breast cell lines as well as primary bone marrow culture obtained from patient with non-malignant haematological disorder. The gelatin microcapsules were successfully grafted into textile materials for the development of cosmetic textiles.

  10. In vitro evaluation of crosslinked electrospun fish gelatin scaffolds.

    Science.gov (United States)

    Gomes, S R; Rodrigues, G; Martins, G G; Henriques, C M R; Silva, J C

    2013-04-01

    Gelatin from cold water fish skin was electrospun, crosslinked and investigated as a substrate for the adhesion and proliferation of cells. Gelatin was first dissolved in either water or concentrated acetic acid and both solutions were successfully electrospun. Cross-linking was achieved via three different routes: glutaraldehyde vapor, genipin and dehydrothermal treatment. Solution's properties (surface tension, electrical conductivity and viscosity) and scaffold's properties (chemical bonds, weight loss and fiber diameters) were measured. Cellular viability was analyzed culturing 3T3 fibroblasts plated on the scaffolds and grown up to 7 days. The cells were fixed and observed with SEM or stained for DNA and F-actin and observed with confocal microscopy. In all scaffolds, the cells attached and spread with varying degrees. The evaluation of cell viability showed proliferation of cells until confluence in scaffolds crosslinked by glutaraldehyde and genipin; however the rate of growth in genipin crosslinked scaffolds was slow, recovering only by day five. The results using the dehydrothermal treatment were the less satisfactory. Our results show that glutaraldehyde treated fish gelatin is the most suitable substrate, of the three studied, for fibroblast adhesion and proliferation.

  11. Gelatin model for training ultrasound-guided puncture

    Directory of Open Access Journals (Sweden)

    Alexandre Campos Moraes Amato

    2015-09-01

    Full Text Available BACKGROUND: It is indispensable that members of the medical profession receive the technical training needed to enable them to rapidly obtain effective vascular access. Training procedures should be used judiciously to familiarize students with the technique. However, existing models are expensive or ineffective, and models need to be developed that are similar to what will be encountered in real patients.OBJECTIVES: To demonstrate creation and application of a gelatin model for training ultrasound-guided puncture.METHOS: The model was made using a mixture of colorless gelatin and water in a transparent plastic receptacle with two pairs of orifices of different diameters, through which two plastic tubes were inserted, to simulate blood vessels.RESULTS: The model was a close approximation to the real medical procedure in several aspects, since gelatin has a similar consistency to human tissues, providing a more faithful reproduction of the tactile sensation at the moment when the needle reaches the interior of a vessel and its contents are aspirated.CONCLUSIONS: The method proposed here can be used to easily construct a low-cost model using everyday materials that is suitable for large-scale training of ultrasound-guided puncture.

  12. Ultrasonic characterization of lactose crystallization in gelatin gels.

    Science.gov (United States)

    Yucel, Umut; Coupland, John N

    2011-01-01

    Ultrasonic velocity and attenuation measurements (2.25 MHz center frequency) were used to follow bulk crystallization of lactose (43% and 46%) from gelatin (1.5% and 3%) gels at 25 °C, and compared to turbidity (500 nm) and isothermal calorimetric measurements. Ultrasonic velocity decreased slightly (approximately 0.5%) during crystallization while ultrasonic attenuation was low in the absence of lactose crystals and increased progressively during crystallization. The lag time before the onset of crystallization decreased and the maximum rate of increase in attenuation during crystallization increased with increasing lactose supersaturation but was not affected by gelatin concentration (P crystallization kinetics in complex food matrices and to be applied on-line. Practical Application: Many foods contain crystals that affect their taste and texture (for example, lactose crystals can give a grainy defect in ice cream). The formation of crystals is often hard to predict so methods to measure the development of crystals inside real foods are useful. In this study, we show that as lactose crystallizes in a gelatin gel the ultrasonic attenuation--capacity to absorb sound--increases and can be related to the amount of crystals present. Ultrasound is easier to apply in real food processing than the existing methodologies.

  13. Release of vancomycin from multilayer coated absorbent gelatin sponges.

    Science.gov (United States)

    Shukla, Anita; Fang, Jean C; Puranam, Sravanthi; Hammond, Paula T

    2012-01-10

    Wounds have the potential to become infected during any surgical procedure. Gelatin sponges that are commonly used to absorb blood during invasive surgeries would benefit tremendously if they released antibiotics. In this work, we have examined coating a commercial gelatin sponge with degradable polymer multilayer films containing vancomycin. The effect of the film on sponge absorption capabilities and the effect of the sponge on drug release kinetics were both examined. Application of vancomycin containing layer-by-layer assembled films to this highly porous substrate greatly increased drug loading up to approximately 880% compared to a flat substrate. Vancomycin drug release was extended out to 6 days compared to 2 days for film coated flat substrates. Additionally, the absorbent properties of the gelatin sponge were actually enhanced by up to 170% due to the presence of the vancomycin film coating. A comparison of film coated sponges with sponges soaked directly in vancomycin demonstrated the ability of the multilayer films to control drug release. Film released vancomycin was also found to remain highly therapeutic with unchanged antimicrobial properties compared to the neat drug, demonstrated by quantifying vancomycin activity against Staphylococcus aureus in vitro.

  14. Hypercalcemia Leads to Delayed Corneal Wound Healing in Ovariectomized Rats.

    Science.gov (United States)

    Nagai, Noriaki; Ogata, Fumihiko; Kawasaki, Naohito; Ito, Yoshimasa; Funakami, Yoshinori; Okamoto, Norio; Shimomura, Yoshikazu

    2015-01-01

    Hypercalcemia is often observed in postmenopausal women as well as in patients with primary hyperparathyroidism or malignant tumors. In this study, we investigated the relationship between calcium ion (Ca(2+)) levels in lacrimal fluid and the rate of corneal wound healing in hypercalcemia using ovariectomized (OVX) rat debrided corneal epithelium. We also determined the effects of Ca(2+) levels on cell adhesion, proliferation and viability in a human cornea epithelial cell line (HCE-T). The calcium content in bones of OVX rats decreased after ovariectomy. Moreover, the Ca(2+) content in the blood of OVX rats was increased 1 month after ovariectomy, and decreased. The Ca(2+) content in the lacrimal fluid of OVX rats was also increased after ovariectomy, and then decreased similarly as in blood. Corneal wound healing in OVX rats was delayed in comparison with Sham rats (control rats), and a close relationship was observed between the Ca(2+) levels in lacrimal fluid and the rate of corneal wound healing in Sham and OVX rats (y=-0.7863x+8.785, R=0.78, n=25). In addition, an enhancement in Ca(2+) levels caused a decrease in the viability in HCE-T cells. It is possible that enhanced Ca(2+) levels in lacrimal fluid may cause a decrease in the viability of corneal epithelial cells, resulting in a delay in corneal wound healing. These findings provide significant information that can be used to design further studies aimed at reducing corneal damage of patients with hypercalcemia.

  15. 2-YEAR EXPERIENCE OF CORNEAL COLLAGEN CROSSLINKING IN KERATOCONUS TREATMENT

    Directory of Open Access Journals (Sweden)

    D. D. Dement’ev

    2015-01-01

    Full Text Available Aim. To assess reliability, efficacy, and stability of corneal collagen crosslinking (CXL results for stage I‑II keratoconus.Patients and methods. 2‑year (2012-2014 results of CXL were analyzed. CXL was performed on 20 eyes of 15 patients (13 men and 2 women, mean age 31 years. Stage 1 keratoconus was diagnosed in 13 eyes, stage 2 keratoconus was diagnosed in 2 eyes. Primary stage 1‑2 keratoconus was diagnosed in 17 eyes, keratoconus after corneal refractive surgery (LASIK, radial keratotomy was diagnosed in 3 eyes. Preoperative and postoperative examination included uncorrected (UCVA and best-corrected (BCVA visual acuity measurement, pachymetry, corneal topography (total astigmatism measurement, and biomicroscopy. Follow-up period varied from 1 to 24 months.Results. All patients reported on vision improvement. Preoperatively, mean UCVA and BCVA were 0.4 and 0.64, respectively. Postoperatively, mean UCVA and BCVA were 0.49 and 0.66, respectively. Preoperatively and postoperatively, total astigmatism was 2.1 D and 2.0 D, respectively, while mean central corneal thickness was 454 μm and 447 μm, respectively.Conclusions. Corneal collagen crosslinking for stage 1‑2 keratoconus provides mild UCVA and BCVA improvement, decrease in total astigmatism and central corneal thickness. CXL provides stable results of treatment of primary stage 1‑2 keratoconus and keratoconus after corneal refractive surgery. 

  16. Characteristics of corneal lens chitin in dragonfly compound eyes.

    Science.gov (United States)

    Kaya, Murat; Sargin, Idris; Al-Jaf, Ivan; Erdogan, Sevil; Arslan, Gulsin

    2016-08-01

    Chitin in the compound eyes of arthropods serves as a part of the visual system. The quality of chitin in such highly specialised body parts deserves more detailed examination. Chitin in the corneal (ommatidial) lenses of dragonfly (Sympetrum fonscolombii) compound eyes was isolated by using the classical chemical method. The chitin content of the corneal lenses was determined to be quite high (20.3±0.85%). The FT-IR analysis showed that corneal lens chitin was in the α-form as found in all arthropod species where mechanical strength is required. The surface morphology analysis by scanning electron microscopy revealed that the outer part of corneal lenses consisted of long chitin fibrils with regular arrays of papillary structures while the smoother inner part had concentric lamellated chitin formation with shorter chitin nanofibrils. Chitinase enzymatic digestion studies, elemental analysis results and the degree of acetylation value showed the purity of chitin samples from corneal lens. The maximum degradation temperature value of the corneal lens chitin was observed at 369.2°C. X-ray analysis revealed that corneal lens chitin has high crystallinity index; 96.4%. Identification of chitin found in ommaditia of insect compound eyes can provide insights into insect vision and chitin-based optical material design studies.

  17. Cytocompatibility of Three Corneal Cell Types with Amniotic Membrane

    Institute of Scientific and Technical Information of China (English)

    CHENJian-su; CHENRui; XUJin-tang; DINGYong; ZHAOSong-bin; LISui-lian

    2004-01-01

    Rabbit limbal corneal epithelial cells, corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth, arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion, amniotic membrane has good scaffold property, diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.

  18. Atmospheric Pressure Non-Equilibrium Plasma as a Green Tool to Crosslink Gelatin Nanofibers

    Science.gov (United States)

    Liguori, Anna; Bigi, Adriana; Colombo, Vittorio; Focarete, Maria Letizia; Gherardi, Matteo; Gualandi, Chiara; Oleari, Maria Chiara; Panzavolta, Silvia

    2016-12-01

    Electrospun gelatin nanofibers attract great interest as a natural biomaterial for cartilage and tendon repair despite their high solubility in aqueous solution, which makes them also difficult to crosslink by means of chemical agents. In this work, we explore the efficiency of non-equilibrium atmospheric pressure plasma in stabilizing gelatin nanofibers. We demonstrate that plasma represents an innovative, easy and environmentally friendly approach to successfully crosslink gelatin electrospun mats directly in the solid state. Plasma treated gelatin mats display increased structural stability and excellent retention of fibrous morphology after immersion in aqueous solution. This method can be successfully applied to induce crosslinking both in pure gelatin and genipin-containing gelatin electrospun nanofibers, the latter requiring an even shorter plasma exposure time. A complete characterization of the crosslinked nanofibres, including mechanical properties, morphological observations, stability in physiological solution and structural modifications, has been carried out in order to get insights on the occurring reactions triggered by plasma.

  19. KARAKTERISTIK EDIBLE FILM YANG DIPRODUKSI DARI KOMBINASI GELATIN KULIT KAKI AYAM DAN SOY PROTEIN ISOLATE

    Directory of Open Access Journals (Sweden)

    Muhamad Hasdar

    2012-09-01

    SDS-PAGE dan menunjukkan sebagai molekul kolagen. Hasil analisis kandungan asam amino edible film menggunakan HPLC dihasilkan komposisi residu asam amino terbesar adalah glysin yaitu 29,42%, 37,88%, 38,32%, 39,28% dan 39,17% pada masing-masing perlakuan. Hal itu menggambarkan bahwa profil protein edible film dapat dipastikan sebagian besar berasal dari kolagen gelatin. Pengamatan dengan scaning electron microscope menunjukkan telah terbentuk cross linking antara molekul protein gelatin dan molekul soy protein isolate dan yang ditunjukan semakin berkurangnya retakan seiring dengan meningkatnya konsentrasi gelatin. Perbedaan kombinasi gelatin kulit kaki ayam dan soy protein isolate untuk membentuk edible film tidak memberikan pengaruh nyata pada kekuatan tarik (tensile strenght, dan kemuluran (elongation, namun berpengaruh nyata pada laju transmisi uap air (Water Vapour Transmision Rate. Kombinasi 95:5 protein gelatin kulit kaki ayam dan soy protein isolate menghasilkan edible film yang terbaik. (Kata kunci: Edible film, Gelatin kaki ayam, Soy protein isolate

  20. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  1. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  2. Impact of facial conformation on canine health: corneal ulceration.

    Directory of Open Access Journals (Sweden)

    Rowena M A Packer

    Full Text Available Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled skull shape, the presence of a nasal fold (wrinkle, and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not, or if a previous diagnosis of corneal ulcer(s was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%, small breed dogs (mean± SE weight: 11.4±1.1 kg, with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio <0.5 were twenty times more likely to be affected than non-brachycephalic dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.

  3. Impact of facial conformation on canine health: corneal ulceration.

    Science.gov (United States)

    Packer, Rowena M A; Hendricks, Anke; Burn, Charlotte C

    2015-01-01

    Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.

  4. Using corneal topography design personalized cataract surgery programs

    Directory of Open Access Journals (Sweden)

    Jin-Ou Huang

    2014-08-01

    Full Text Available AIM:To investigate how to design personalized cataract surgery programs to achieve surgical correction of preoperative corneal astigmatism with surgical astigmatism under the guidance of corneal topography, improve postoperative visual quality and reduce the cost of treatment. METHODS: Totally 202 cases(226 eyescataract patients were divided into randomized treatment group and individualized treatment group. According to the method and location of the incision, randomized treatment group were divided into 8 groups. Surgical astigmatism after different incision were calculated with the use of preoperative and postoperative corneal astigmatism through vector analysis method. Individualized treatment groups were designed personably for surgical method with reference of every surgically induced astigmatism, the surgical method chooses the type of surgical incision based on close link between preoperative corneal astigmatism and surgically induced astigmatism, and the incision was located in the steep meridian. The postoperative corneal astigmatism of individualized treatment group was observed. RESULTS: Postoperative corneal astigmatism of individualized treatment group were lower than that of 3.0mm clear corneal tunnel incision in the randomized treatment group, there were statistically significance difference, while with 3.0mm sclera tunnel incision group there were no statistically significance difference. After 55.8% of patients with the use of individualized surgical plan could undergo the operation of extracapsular cataract extraction with relatively low cost and rigid intraocular lens implantation, the per capita cost of treatment could be reduced. CONCLUSION: Personalized cataract surgery programs are designed to achieve surgical correction of preoperative corneal astigmatism under the use of corneal topography, improve postoperative visual quality and reduce the cost of treatment.

  5. Barrier layers against oxygen transmission on the basis of electron beam cured methacrylated gelatin

    Science.gov (United States)

    Scherzer, Tom

    1997-08-01

    The development of barrier layers against oxygen transmission on the basis of radiation-curable methacrylated gelatin will be reported. The electron beam cured gelatin coatings show an extremely low oxygen permeability and a high resistance against boiling water. Moreover, the methacrylated gelatins possess good adhesion characteristics. Therefore, they are suited as barrier adhesives in laminates for food packaging applications. If substrate foils from biodegradable polymers are used, the development of completely biodegradable packaging materials seems to be possible.

  6. Optical properties of gelatin/CdS bionanocomposite and its conformational change**

    Institute of Scientific and Technical Information of China (English)

    Tang Shi-hua; Li You-qun; Wang Jun; Wang Bai-yang

    2013-01-01

    BACKGROUND:The properties, integration mechanism and conformation change of protein are closely related with the biological effects of nanocomposites. OBJECTIVE:To study the optical properties and integration mechanism of gelatin/CdS bionanocomposite, and to analyze the conformation change of gelatin macromolecule at pH 12.0. METHODS:The gelatin/CdS bionanocomposites were synthesized via one-pot chemical route with the materials of gelatin, cadmium acetate and Na 2 S•9H 2 O through adding the Cd2+and S2−solution into the gelatin dilute solution at the temperature of 296, 302 and 308 K, and with the concentration of 8×10−6-1.2×10−3 RESULTS AND CONCLUSION:Transmission electron microscopy images showed that the morphology of gelatin/CdS nanocomposites was mainly chain-shaped. The ultraviolet-visible spectroscopy showed that the gelatin/CdS nanocomposites band gap was decreased with the increasing in both the CdS concentration and temperature, and they showed an obvious quantum size effect. The dynamic light scattering showed that theζpotential was negative and decreased slightly with the increasing in concentration of CdS. The Fourier transform infrared spectroscopy showed that level ofα-helix andβ-sheets in gelatin macromolecular conformation was decreased and theβ-turns level was increased. The gelatin/Cd 2+complex and gelatin/CdS nanocomposites were formed on the basis of various observations, the most plausible mechanism is proposed for the integration of gelatin/CdS nanocomposites, which includes the coordination (Cd2+with the oxygen of carbonyl group in gelatin molecular chain), vulcanization and surface coated. The shape,ζpotential and optical properties of samples were characterized by transmission electron microscope, dynamic light scattering, X-ray diffraction, ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy.

  7. Study on encapsulation of chlorine dioxide in gelatin microsphere for reducing release rate

    OpenAIRE

    Ci, Ying; Wang,Lin; Guo, YanChuan; Sun, Ruixue; Wang, Xijie; Li, Jinyou

    2015-01-01

    Objective: This study aims to explore the effects of encapsulation of chlorine dioxide in a hydrophilic biodegradable polymer gelatin to reduce its release rate. Methods: An emulsification-coacervation method was adopted. The characterizations of chlorine dioxide-gelatin microspheres were described. Using UV-vis spectrophotometer the λmax of chlorine dioxide was observed at 358 nm. The particle size and distribution of chlorine oxide-gelatin microspheres was measured by a dynamic light scatte...

  8. Influence of gelatine on corrosion behavior of copper in acidic media

    OpenAIRE

    Todorović Dragiša A.; Milenković Dragan D.; Milosavljević Milutin M.; Marković Dragan A.

    2012-01-01

    This paper presents the results of gelatin and benzotriazole (BTA) inhibitory action on copper in the acid medium by the method of weight loss. The investigation was carried out in the citric acid solution (1, 5 and 20%) at the temperature of 293 K. Under such conditions, the gelatin showed higher efficiency of corrosion protection in comparison to BTA. The results, obtained through the Gibbs and Langmuir adsorption isotherm, show that gelatin adsorption on copper surface obey the Langm...

  9. Determining the Equation of State (EoS) Parameters for Ballistic Gelatin

    Science.gov (United States)

    2015-09-01

    ARL-TR-7467 ● SEP 2015 US Army Research Laboratory Determining the Equation of State (EoS) Parameters for Ballistic Gelatin ...EoS) Parameters for Ballistic Gelatin by Yolin Huang Weapons and Materials Research Directorate, ARL Approved for...State (EoS) Parameters for Ballistic Gelatin 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Yolin Huang 5d

  10. Preparation, Electromechanical, and Structural Study of Carbon Nanotube/Gelatin Nanocomposites

    Science.gov (United States)

    2008-01-15

    composite [22]. Gelatin is a high molecular weight polypeptide obtained by controlled hydrolysis of collagen [23]. It is a good film and particle... CNTs ) are a new form of carbon, consisting of concentric cylinders of graphite layers rolled into graphene cylinders. The combination of their shape...shows the incorporation of the MWNT into the gelatin fibrils and a possible cross-linked MWNT /gelatin composite. The interaction between CNT and SDS

  11. Methylene blue-related corneal edema and iris discoloration.

    Science.gov (United States)

    Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Aslanci, Mehmet Emin; Baykara, Mehmet

    2016-04-01

    We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes.

  12. Repositioning of pedicle conjunctival flap performed for refractory corneal ulcer

    Directory of Open Access Journals (Sweden)

    Ashok Sharma

    2014-01-01

    Full Text Available A 50-year-old male was referred with a previous history of conjunctival flap (CF for a nonhealing fungal corneal ulcer with extreme corneal thinning in the right eye. The peritomy for the CF extended from 6:30 to 9:30 clock h on the cornea. The CF was disengaged, peritomy area deepithelialized, and CF was repositioned. He later underwent penetrating keratoplasty and achieved 20/40 best corrected visual acuity. The authors present a new concept for surgically repositioning CF s to the original site immediately after healing of the corneal ulcer.

  13. Repositioning of pedicle conjunctival flap performed for refractory corneal ulcer.

    Science.gov (United States)

    Sharma, Ashok; Mohan, Kanwar; Sharma, Rajan; Nirankari, Verinder S

    2014-01-01

    A 50-year-old male was referred with a previous history of conjunctival flap (CF) for a nonhealing fungal corneal ulcer with extreme corneal thinning in the right eye. The peritomy for the CF extended from 6:30 to 9:30 clock h on the cornea. The CF was disengaged, peritomy area deepithelialized, and CF was repositioned. He later underwent penetrating keratoplasty and achieved 20/40 best corrected visual acuity. The authors present a new concept for surgically repositioning CF s to the original site immediately after healing of the corneal ulcer.

  14. Septo-optic dysplasia with bilateral congenital corneal anesthesia.

    Science.gov (United States)

    Chow, Clement C; Kapur, Rashmi; Wood, Michael G; Setabutr, Pete; Tu, Elmer Y

    2009-10-01

    Septo-optic dysplasia, or de Morsier syndrome, is characterized by optic nerve hypoplasia with an absent septum pellucidum and/or pituitary abnormalities. Congenital corneal anesthesia is a rare disorder that has been associated with many neurological disorders. Here we present a patient with both conditions who was successfully treated with permanent lateral tarsorrhaphy and aggressive lubrication. To our knowledge, congenital corneal anesthesia has not been reported in association with septo-optic dysplasia. The purpose of this report is to make pediatric ophthalmologists aware of a potential association since the diagnosis of congenital corneal anesthesia is often difficult and delayed.

  15. UUnilateral corneal edema caused by a hidden foreign body.

    Science.gov (United States)

    Galvis, V; Tello, A; Frederick, G A; Laiton, A N

    2017-09-01

    A middle-aged adult male was referred to our institution due to unilateral corneal edema for a possible corneal transplant. At first, the patient denied a history of trauma. A small foreign body, which had been overlooked by the primary ophthalmologist, was detected by gonioscopy, embedded in the anterior chamber angle. It was successfully surgically removed and visual results were good. In any patient with unilateral unexplained corneal edema, it is necessary to rule out the presence of a foreign body in the anterior chamber. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Corneal modeling using conic section fits of PAR corneal topography system measurements

    Science.gov (United States)

    Zipper, Stanley; Manns, Fabrice; Fernandez, Viviana; Sandadi, Samith; Ho, Arthur; Parel, Jean-Marie A.

    2001-06-01

    The purpose of this study was to measure the average shape and variability of human corneas and to develop a tool for analyzing, height, curvature, and aberrations based on a conic section model. Fresh Eye Bank Eyes were placed in Dextran until the corneal thickness reached a physiological value. The eyes were placed in a custom made holder and measured using an intraoperative PAR Corneal Topography System (CTS) mounted on an operation microscope. Topography was measured before and after removal of the epithelium. A series of MATLAB functions were written to analyze the raw-z (height) data in polar coordinates. The functions fit conic sections to the PAR CTS data along hemi-meridians at 5 degree(s) intervals. The conic shape factor and apical radius were used to calculate and display the curvature. The dependence of these parameters with meridional position was examined.

  17. Corneal melanosis successfully treated using topical mitomycin-C and alcohol corneal epitheliectomy: a 3-year follow-up case report

    Directory of Open Access Journals (Sweden)

    Mehmet Balcı

    2015-08-01

    Full Text Available ABSTRACTWe report a case of primary acquired corneal melanosis without atypia associated with corneal haze in a patient with a history of limbal malignant melanoma and the effect of mitomycin-C. A 75-year-old woman with a history of limbal malignant melanoma presented with loss of vision in right eye. Corneal examination showed a patchy melanotic pigmentation with a central haze. Topical mitomycin-C improved visual acuity and corneal haze. However, the pigmented lesions persisted, and they were removed with alcohol corneal epitheliectomy. Histopathological examination demonstrated primary acquired melanosis without atypia. The lesions were successfully removed, and there were no recurrences during the follow-up period of 36 months. The association of conjunctival and corneal melanosis without atypia is a rare condition. In addition, co-existence of central corneal haze and melanosis may decrease visual acuity. Topical mitomycin-C and alcohol corneal epitheliectomy can be useful treatments in this condition.

  18. Corneal melanosis successfully treated using topical mitomycin-C and alcohol corneal epitheliectomy: a 3-year follow-up case report.

    Science.gov (United States)

    Balcı, Mehmet; Yağcı, Ramazan; Güler, Emre; Haltaş, Hacer; Duman, Rahmi; Hepşen, İbrahim F

    2015-01-01

    We report a case of primary acquired corneal melanosis without atypia associated with corneal haze in a patient with a history of limbal malignant melanoma and the effect of mitomycin-C. A 75-year-old woman with a history of limbal malignant melanoma presented with loss of vision in right eye. Corneal examination showed a patchy melanotic pigmentation with a central haze. Topical mitomycin-C improved visual acuity and corneal haze. However, the pigmented lesions persisted, and they were removed with alcohol corneal epitheliectomy. Histopathological examination demonstrated primary acquired melanosis without atypia. The lesions were successfully removed, and there were no recurrences during the follow-up period of 36 months. The association of conjunctival and corneal melanosis without atypia is a rare condition. In addition, co-existence of central corneal haze and melanosis may decrease visual acuity. Topical mitomycin-C and alcohol corneal epitheliectomy can be useful treatments in this condition.

  19. Intraoperative Corneal Thickness Changes during Pulsed Accelerated Corneal Cross-Linking Using Isotonic Riboflavin with HPMC

    Directory of Open Access Journals (Sweden)

    Ahmed M. Sherif

    2016-01-01

    Full Text Available Purpose. To evaluate corneal thickness changes during pulsed accelerated corneal cross-linking (CXL for keratoconus using a new isotonic riboflavin formula. Methods. In this prospective, interventional, clinical study patients with grades 1-2 keratoconus (Amsler-Krumeich classification underwent pulsed accelerated (30 mW/cm2 CXL after application of an isotonic riboflavin solution (0.1% with HPMC for 10 minutes. Central corneal thickness (CCT measurements were taken using ultrasound pachymetry before and after epithelial removal, after riboflavin soaking, and immediately after completion of UVA treatment. Results. Twenty eyes of 11 patients (4 males, 7 females were enrolled. Mean patient age was 26±3 (range from 18 to 30 years. No intraoperative or postoperative complications were observed in any of the patients. Mean CCT was 507±35 μm (range: 559–459 μm before and 475±40 μm (range: 535–420 μm after epithelial removal (P<0.001. After 10 minutes of riboflavin instillation, there was a statistically significant decrease of CCT by 6.2% from 475±40 μm (range: 535–420 μm to 446±31 μm (range: 508–400 (P<0.005. There was no other statistically significant change of CCT during UVA irradiation. Conclusions. A significant decrease of corneal thickness was demonstrated during the isotonic riboflavin with HPMC application while there was no significant change during the pulsed accelerated UVA irradiation.

  20. Variation of Hydroxyapatite Content in Soft Gelatin Affects Mesenchymal Stem Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Fahsai Kantawong

    2016-01-01

    Full Text Available Gelatin is a common material used in tissue engineering and hydroxyapatite (HA has a composition and structure similar to natural bone mineral. HA is also used to increase the adhesion ability of scaffolds. The physical and mechanical properties of gelatin, together with the chemical properties of HA, can affect cell differentiation. The main purpose of this study is to investigate the gene expression of human mesenchymal stem cells (HMSCs upon culturing on gelatin composite with HA. Low amounts of HA were introduced into the gelatin in order to modulate properties of gelatin. Three types of hydrogel were fabricated by glutaraldehyde crosslinking before lyophilization to produce the porous 3D structure: (1 pure gelatin, (2 0.5 mg/ml HA in gelatin, and (3 1 mg/ml HA in gelatin. The fabricated hydrogels were used as scaffolds to cultivate HMSCs for two periods - 24 hours and 3 weeks. The results showed that all types of fabricated hydrogels could be used to cultivate HMSCs. Changes of gene expressions indicated that the HMSCs cultured on the 1 mg/ml HA in gelatin showed neuronal lineage-specific differentiation.

  1. Hydrolyzed collagen (gelatin decreases food efficiency and the bioavailability of high-quality protein in rats

    Directory of Open Access Journals (Sweden)

    Cláudia Cantelli Daud BORDIN

    2015-08-01

    Full Text Available Objective Although deficient in all indispensable amino acids, gelatin is used in protein-restricted diets. Food efficiency and protein quality of casein and gelatin mixtures in low protein diets in Wistar rats were investigated. Methods The rats were treated with protein-restricted diets (10.0 and 12.5% containing casein (control diets, casein with gelatin mixtures (4:1 of protein content, and gelatin as sources of protein. The food conversion ratio, protein efficiency ratio, relative and corrected protein efficiency ratio, true protein digestibility, and hepatic parameters were estimated. Results After 28 days of the experiment, food efficiency of 10.0% casein/gelatin diet decreased when compared to that of 10.0% casein diet, and the protein efficiency ratio of the casein/gelatin mixtures (10.0%=2.41 and 12.5%=2.03 were lower than those of the casein (10.0%=2.90 and 12.5%=2.32. After 42 days of the experiment, the weight of the liver of the animals treated with 10.0 and 12.5% casein/gelatin diets, and the liver protein retention of the 12.5% casein/gelatin diet group of animals were lower than those of the control group. Conclusion Gelatin decreases food efficiency and high-quality protein bioavailability in protein-restricted diets.

  2. Gelatin nanoparticles for use as a vaccine adjuvant in intranasal immunizations

    Science.gov (United States)

    Washington, Tara D.

    Vaccine adjuvants are used to increase the immune response in the delivery of subunit antigens. Currently the only FDA approved adjuvants are aluminum based and must be delivered parenterally. Nasal mucoadhesive vaccine administration can decrease cost, increase efficiency and increase patient compliance. The purpose of this study was to develop a mucoadhesive gelatin nanoparticle >500 nm in diameter that can be used to encapsulate a model protein antigen. The particles were prepared by nanoprecipitation of a gelatin solution with acetone. Thiol groups were incubated with gelatin to increase mucoadhesivness at 20, 40, and 80 mg per 1 gram of gelatin. The thiolation chemistry was characterized using UV-Vis and x-ray photoelectron spectroscopy (XPS). The total amount of sulfur present in the gelatin was determined to be 7.48, 30.53, and 46.75 mmol/gram respectively. However XPS analysis revealed that there was no substantial difference between surface sulfur content of the unmodified gelatin nanoparticles and the gelatin nanoparticles modified with 80 mg of iminothiolane. Particle size, charge and morphology were determined using laser light diffraction, atomic force microscopy microscopy and electron microscopy. The average diameter of the unmodified gelatin was 171 nm. The average diameter of the thiolated gelatin nanoparticles was 275 nm. The polydispersity index was approximately 0.61 +/- 0 .04 for all nanoparticles. The zeta (zeta) potential of the unmodified gelatin nanoparticles was -21.5 +/- 2.0 mV and the zeta-potential of the modified gelatin nanoparticles was -25.2 +/- 1.5, -27.3 +/- 0.8, and -28.6 +/- 3.0 mV for the 20, 40, and 80 thiolated gelatin nanoparticles. Particle encapsulation efficiency (EE) and release kinetics were conducted using fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) as a model antigen. The EE of the nanoparticles increased from 35.0% (unmodified gelatin) to 82.5% (highest modified gelatin). Particles encapsulated with

  3. Gelatinization kinetic of waxy starches under pressure according to ionic strength

    Science.gov (United States)

    Simonin, Hélène; Guyon, Claire; de Lamballerie, Marie; Lebail, Alain

    2010-12-01

    High pressure is a potential technology for the texturization of food products at ambient temperature. In this area, waxy starches are particularly interesting because they gelatinize quickly under sufficient pressure. However, gelatinization may be influenced by other components in the food matrix. Here, we investigate the influence of increasing ionic strength on gelatinization rate and kinetics at 500 MPa for waxy corn and waxy rice starches. We show that increasing ionic strength strongly retards and inhibits starch gelatinization under pressure and leads to heterogeneous gels with remnant granules.

  4. Gelatinization and solubility of corn starch during heating in excess water: new insights.

    Science.gov (United States)

    Ratnayake, Wajira S; Jackson, David S

    2006-05-17

    Starch gelatinization is associated with the disruption of granular structure causing starch molecules to disperse in water. This study was designed to examine starch granules as they were heated in water, and their resulting morphological, structural, and solubility traits. The results indicate that starch gelatinization is a more complex process than the previously suggested order-to-disorder transition. The energy absorbed by the granules facilitates the rearrangement or formation of new bonds among molecules prior to the temperatures normally associated with the melting of amylopectin crystallites during gelatinization. It is also evident that amylose plays an important role during the initial stages of corn starch gelatinization.

  5. Core-shell nanofibers: Integrating the bioactivity of gelatin and the mechanical property of polyvinyl alcohol.

    Science.gov (United States)

    Merkle, Valerie M; Zeng, Like; Slepian, Marvin J; Wu, Xiaoyi

    2014-04-01

    Coaxial electrospinning is used to fabricate nanofibers with gelatin in the shell and polyvinyl alcohol (PVA) in the core in order to derive mechanical strength from PVA and bioactivity from gelatin. At a 1:1 PVA/gelatin mass ratio, the core-shell nanofiber scaffolds display a Young's modulus of 168.6 ± 36.5 MPa and a tensile strength of 5.42 ± 1.95 MPa, which are significantly higher than those of the scaffolds composed solely of gelatin or PVA. The Young's modulus and tensile strength of the core-shell nanofibers are further improved by reducing the PVA/gelatin mass ratio from 1:1 to 1:3. The mechanical analysis of the core-shell nanofibers suggests that the presence of the gelatin shell may improve the molecular alignment of the PVA core, transforming the semi-crystalline, plastic PVA into a more crystallized, elastic PVA, and enhancing the mechanical properties of the core. Lastly, the PVA/gelatin core-shell nanofibers possess cellular viability, proliferation, and adhesion similar to these of the gelatin nanofibers, and show significantly higher proliferation and adhesion than the PVA nanofibers. Taken together, the coaxial electrospinning of nanofibers with a core-shell structure permits integration of the bioactivity of gelatin and the mechanical strength of PVA in single fibers.

  6. Enhancing water repellence and mechanical properties of gelatin films by tannin addition.

    Science.gov (United States)

    Peña, Cristina; de la Caba, Koro; Eceiza, Arantxa; Ruseckaite, Roxana; Mondragon, Iñaki

    2010-09-01

    In order to reduce pollution caused by traditional non-biodegradable plastic films, renewable raw materials from plants and wastes of meat industries have been employed in this work. A hydrolysable chestnut-tree tannin was used for gelatin modification. Films of gelatin and gelatin-tannin were obtained by casting at room conditions. Transition temperatures of both gelatin and gelatin-tannin systems were determined by differential scanning calorimetry (DSC). Glass transition temperatures of modified gelatin occurred at higher temperatures than for neat gelatin. Enthalpy and temperature of helix-coil transition decreased when tannin content increased due to variations in the helical structure of gelatin as a consequence of tannin presence in agreement with X-ray analysis. Mechanical and thermal behaviour varied as a function of the content of tannin, showing optimum values for films modified with 10 wt% tannin. The transparency of films was maintained after modification with tannin. Solubility and swelling tests of the films revealed that the presence of tannin reduced the water affinity of gelatin. (c) 2010 Elsevier Ltd. All rights reserved.

  7. Generation of corneal epithelial cells from induced pluripotent stem cells derived from human dermal fibroblast and corneal limbal epithelium.

    Directory of Open Access Journals (Sweden)

    Ryuhei Hayashi

    Full Text Available Induced pluripotent stem (iPS cells can be established from somatic cells. However, there is currently no established strategy to generate corneal epithelial cells from iPS cells. In this study, we investigated whether corneal epithelial cells could be differentiated from iPS cells. We tested 2 distinct sources: human adult dermal fibroblast (HDF-derived iPS cells (253G1 and human adult corneal limbal epithelial cells (HLEC-derived iPS cells (L1B41. We first established iPS cells from HLEC by introducing the Yamanaka 4 factors. Corneal epithelial cells were successfully induced from the iPS cells by the stromal cell-derived inducing activity (SDIA differentiation method, as Pax6(+/K12(+ corneal epithelial colonies were observed after prolonged differentiation culture (12 weeks or later in both the L1B41 and 253G1 iPS cells following retinal pigment epithelial and lens cell induction. Interestingly, the corneal epithelial differentiation efficiency was higher in L1B41 than in 253G1. DNA methylation analysis revealed that a small proportion of differentially methylated regions still existed between L1B41 and 253G1 iPS cells even though no significant difference in methylation status was detected in the specific corneal epithelium-related genes such as K12, K3, and Pax6. The present study is the first to demonstrate a strategy for corneal epithelial cell differentiation from human iPS cells, and further suggests that the epigenomic status is associated with the propensity of iPS cells to differentiate into corneal epithelial cells.

  8. Automatic system for corneal ulcer diagnostic: II

    Science.gov (United States)

    Ventura, Liliane; Chiaradia, Caio; Faria de Sousa, Sidney J.

    1998-06-01

    Corneal Ulcer is a deepithelization of the cornea and it is a very common disease in agricultural countries. The clinician most used parameter in order to identify a favorable ulcer evolution is the regress of the affected area. However, this kind of evaluation is subjective, once just the horizontal and vertical axes are measured based on a graduated scale and the affected area is estimated. Also, the registration of the disease is made by photographs. In order to overcome the subjectiveness and to register the images in a more accessible way (hard disks, floppy disks, etc.), we have developed an automatic system in order to evaluate the affected area (the ulcer). An optical system is implemented in a Slit Lamp (SL) and connected to a CCD detector. The image is displayed in PC monitor by a commercial frame grabber and a dedicated software for determining the area of the ulcer (precision of 20 mm) has been developed.

  9. [Corneal collagen cross-linking for keratoconus].

    Science.gov (United States)

    Zotov, V V; Pashtaev, N P; Pozdeeva, N A

    2015-01-01

    Over the last decade, corneal collagen cross-linking (CXL) has become a conventional treatment method for progressive keratoconus. Laboratory studies have shown that CXL increases the diameter of collagen fibers and also the number of intra- and interfibrillar cross-links, thus, increasing biomechanical strength of the irradiated cornea. As confirmed by a series of clinical and randomized controlled trials, CXL is able to slow down and, perhaps, to stop the progression of keratoconus. In most post-CXL patients visual acuity improves, while keratometric readings, spherical equivalent, and higher order aberrations reduce. Although published results prove CXL effective in the treatment of progressive keratoconus, its late consequences are yet unknown. This article reviews the stages of CXL development and results of published experimental and clinical studies. Prospects for CXL modifications that do not require epithelial debridement are discussed.

  10. Another Risk From Cigarette Smoking: Corneal Burn

    Directory of Open Access Journals (Sweden)

    Volkan Hürmeriç

    2012-12-01

    Full Text Available A 21-year-old male presented with corneal injury in his left eye after one of his friends had moved his arm backwards and accidentally hit his eye with the lit end of a cigarette. Slit lamp examination revealed epithelial defect and significant stromal edema at the superior temporal quadrant of the cornea. Cigarette ashes were noted in his lashes and inferior conjunctival fornix at the initial examination in the emergency service. 6 weeks after the injury, slit lamp examination revealed stromal thinning and haze in the temporal part of the cornea. His best spectacle-corrected distance visual acuity was 20/25 with a refractive error of -6.75x135 diopters in the left eye. Our case demonstrates that ocular thermal injury due to cigarette smoking can cause serious damage to the ocular tissues. (Turk J Oph thal mol 2012; 42: 484-5

  11. Design and validation of a corneal bioreactor.

    Science.gov (United States)

    Leonard, Elissa K; Pai, Vincent H; Amberg, Philip; Gardner, Jens; Orwin, Elizabeth J

    2012-12-01

    Mechanical strain is an important signal that influences the behavior and properties of cells in a wide variety of tissues. Physiologically similar mechanical strain can revert cultured cells to a more normal phenotype. Here, we have demonstrated that 3% equibiaxial (EB) and uniaxial strains confer favorable protein expression in cultured rabbit corneal fibroblasts (RCFs), with approximately 35% and 65% reduction in expression of α-smooth muscle actin (α-SMA), respectively. We have designed a novel bioreactor that is capable of imparting up to 7% EB strain and up to 6% EB strain using a cornea-shaped post. Additional features of the bioreactor include the application of shear stress to cells in culture and the ability to image cells using optical coherence microscopy (OCM) without being removed from the system. Copyright © 2012 Wiley Periodicals, Inc.

  12. Putative Corneal Neuralgia Responding to Vitamin D Supplementation

    Directory of Open Access Journals (Sweden)

    Eric L. Singman

    2013-09-01

    Full Text Available A patient with putative corneal neuralgia was incidentally discovered to have hypovitaminosis D. Supplementation of vitamin D appears to have led to a resolution of the patient's pain, whereas other efforts to treat the patient were unsuccessful.

  13. Review of photokeratitis: Corneal response to ultraviolet radiation (UVR exposure*

    Directory of Open Access Journals (Sweden)

    L A. Moore

    2010-12-01

    Full Text Available The development of photokeratitis in response to natural solar ultraviolet radiation (UVR is prevalent in individuals participating in outdoor recreational activities in environments with high reflective surfaces, such as beach activities, water sports and snow skiing. Eye care practitioners (ECPs are frequently encouraged by manufacturers and researchers to recommend UVR-blocking eyewear in the form of sunglasses and contact lenses. However, little is known about the precise nature of the corneal tissue response in the development of photokeratitis. This paper reviews the mechanisms responsible for the development of photokeratitis. Clinical signs and symptoms of photokeratitis, UVR corneal threshold and action spectra, corneal cellular changes and ocular protection from corneal UVR exposure are discussed. The content of this article will be useful to ECPs in making appropriate recommendations when prescribing UVR-protec-tive eyewear. (S Afr Optom 2010 69(3 123-131

  14. Treatment of Corneal Lesions in Individuals with Vernal Keratoconjunctivitis

    Directory of Open Access Journals (Sweden)

    Naoki Kumagai

    2005-01-01

    Full Text Available Vernal keratoconjunctivitis, a severe form of allergic conjunctival disease, is characterized by the development of various types of corneal lesions in conjunction with proliferative changes in the conjunctiva. Expression of bioactive substances, such as chemokines and adhesion molecules, by corneal fibroblasts likely contribute to the formation of corneal lesions by promoting local infiltration, activation, and survival of immune cells. Proliferation and deposition of extracellular matrix by conjunctival fibroblasts also may provide conditions which support the activation and survival of immune cells. Topical administration of corticosteroids is the principal mode of treatment for conjunctival inflammation in individuals with vernal keratoconjunctivitis. In some individuals, however, the surgical removal of conjunctival giant papillae or of corneal plaques is indicated.

  15. Substratum topography modulates corneal fibroblast to myofibroblast transformation.

    Science.gov (United States)

    Myrna, Kathern E; Mendonsa, Rima; Russell, Paul; Pot, Simon A; Liliensiek, Sara J; Jester, James V; Nealey, Paul F; Brown, Donald; Murphy, Christopher J

    2012-02-01

    The transition of corneal fibroblasts to the myofibroblast phenotype is known to be important in wound healing. The purpose of this study was to determine the effect of topographic cues on TGFβ-induced myofibroblast transformation of corneal cells. Rabbit corneal fibroblasts were cultured on nanopatterned surfaces having topographic features of varying sizes. Cells were cultured in media containing TGFβ at concentrations ranging from 0 to 10 ng/mL. RNA and protein were collected from cells cultured on topographically patterned and planar substrates and analyzed for the myofibroblast marker α-smooth muscle actin (αSMA) and Smad7 expression by quantitative real time PCR. Western blot and immunocytochemistry analysis for αSMA were also performed. Cells grown on patterned surfaces demonstrated significantly reduced levels of αSMA (P fibroblast phenotype while pathologic microenvironmental alterations may be permissive for increased myofibroblast differentiation and the development of fibrosis and corneal haze.

  16. Crystalline Subtype of Pre-Descemetic Corneal Dystrophy

    Directory of Open Access Journals (Sweden)

    Rosa Dolz-Marco

    2014-01-01

    Full Text Available Purpose: To report corneal findings in a familial case of the crystalline subtype of pre- Descemetic corneal dystrophy. Case Report: A 19-year-old girl and her 44-year-old mother were found to have asymptomatic, bilateral, punctiform and multi-colored crystalline opacities across the whole posterior layer of the corneas. Endothelial specular microscopy revealed the presence of white round flecks located at different levels anterior to the endothelium. No systemic abnormalities or medications could be related to account for these findings. Conclusion: To the best of our knowledge, this is the third familial report of this rare corneal disorder. Differential diagnosis may include Schnyder corneal dystrophy, cystinosis, Bietti΄s dystrophy and monoclonal gammopathy.

  17. Shadow photogrammetric apparatus for the quantitative evaluation of corneal buttons.

    Science.gov (United States)

    Denham, D; Mandelbaum, S; Parel, J M; Holland, S; Pflugfelder, S; Parel, J M

    1989-11-01

    We have developed a technique for the accurate, quantitative, geometric evaluation of trephined and punched corneal buttons. A magnified shadow of the frontal and edge views of a corneal button mounted on the rotary stage of a modified optical comparator is projected onto the screen of the comparator and photographed. This process takes approximately three minutes. The diameters and edge profile at any meridian photographed can subsequently be analyzed from the film. The precision in measuring the diameters of well cut corneal buttons is +/- 23 microns, and in measuring the angle of the edge profile is +/- 1 degree. Statistical analysis of inter observer variability indicated excellent reproducibility of measurements. Shadow photogrammetry offers a standardized, accurate, and reproducible method for analysis of corneal trephination.

  18. Central Corneal Thickness in Adult Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The central corneal thickness (CCT) in age 48 years or less of Chinese was characterized and its relationship with gender, age, refraction and intraocular pressure (IOP) was investigated.Right eyes of 1669 participants were included in this study (880 men, 52.7 % and 789 women,47.3 %). Mean age of the samples was 23.8±5.9 years. After the examination of corneal topography and refraction, Goldman applanation tonometry was carried out by one physician. Tonometric values were the mean of three consecutive readings. Subsequently, another physician carried out ultrasonic pachymetry with the DGH 2000 AP ultrasonic pachymeter. Six measuremen ts were made at the center of the cornea of each eye. The mean value was used for analysis. The results showed that mean CCT of male participants was 551.33± 34. 62 μm, 5.79 μm more than that of female participants. Linear regression analyses revealed that CCT was negatively related with age only in female and no association was found between refractive status and CCT. IOP was positively related to CCT, and there was a difference in IOP of 1.5 mmHg (1 mmHg=0. 133 kPa) per 100 μm difference in CCT. Ocular hypertension group was prone to have thicker cornea than average. The results indicated that in adult Chinese CCT tended to decrease with aging in female only. IOP measured by Goldmann tonometry was positively related with CCT so that CCT should be measured along with IOP.

  19. Clinical utility of the KAMRA corneal inlay

    Directory of Open Access Journals (Sweden)

    Naroo SA

    2016-05-01

    Full Text Available Shehzad Anjam Naroo, Paramdeep Singh Bilkhu Ophthalmic Research Group, School of Life & Health Sciences, Aston University, Birmingham, UK Abstract: The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye, with a large proportion of patients achieving Jaeger (J 2 to J1 (~0.00 logMAR to ~0.10 logMAR at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better. The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient’s visual function. Keywords: presbyopia, refractive surgery, implants, cornea

  20. The Active Metabolite of Leflunomide A771726 Inhibits Corneal Neovascularization

    Institute of Scientific and Technical Information of China (English)

    Mingchang ZHANG; Nian HAO; Fang BIAN

    2008-01-01

    The effects of A771726, the active metabolite of leflunomide, on experimental rat corneal neovascularization (NV) in vivo and on cultured human umbilical vein endothelial cells in vitro were studied. The corneal NV was induced by alkali burn in 40 SD rats. The rats were randomly divided into 4 groups with 10 rats in each group. Group A was treated with 0.9% sodium chloride (control group), and group B, group C and group D were given different concentrations of A771726 eye drops (0.5%,l.0%,2.0% respectively) 4 times daily during days 0-28. The occurrence and development of corneal NV were observed at 4,7,14,21 and 28 day after alkali burn by a slit lamp microscope. The cultured human umbilical vein endothelial cells (ECV-304) were incubated with A771726 solution at different concentrations (20,40,80,160,320μmol/L) for 36h. The proliferation of cells was assessed by methyl thiazolyl tetrazolium (MTT), and the expression of proliferating cell nuclear antigen (PCNA) in cells was detected by using immunofluorescence under the laser confocal microscope. The rat model showed that the onset of corneal NV was delayed and progression of corneal NV was inhibited in the groups C and D. The corneal NV areas in groups C and D were significantly smaller than in groups A and B (P0.05). A771726 solution (≥40μmol/L) could inhibit proliferation of human umbilical vein endothelial cells and decrease the expression of PCNA in cells significantly. A771726, as the active metabolite of leflunomide, strongly prevented corneal NV induced by alkali burn in the in vivo model, and inhibited proliferation of human umbilical vein endothelial cells in the in vitro model. Therefore, A771726 may serve as an angiogenic inhibitor in the treatment of corneal NV.

  1. Pilot Study of Corneal Sensitivity and Its Association in Keratoconus.

    Science.gov (United States)

    Mandathara, Preeji S; Stapleton, Fiona J; Kokkinakis, Jim; Willcox, Mark D P

    2017-02-01

    To evaluate corneal sensitivity and its association with other clinical parameters in keratoconus. Twenty-four subjects with keratoconus aged between 18 and 65 years were recruited in this cross-sectional study. Ocular symptoms, corneal topography, tear variables such as tear osmolarity, volume and lower tear meniscus height, ocular surface staining, central sensitivity threshold (CST), and corneal subepithelial nerve mapping were obtained. Association between central CST and other clinical variables was examined using the Spearman correlation coefficient. Partial correlation was performed to control for effects of confounding factors. Data from the most severe eye of each subject were included in analyses. Based on the maximum simulated keratometry (Kmax) reading, subjects were graded as having mild (N = 11; K max ≤ 52 D) or severe (N = 13; K max > 52 D) keratoconus. Central corneal sensitivity was lower (ie, increased CST) in the severe keratoconus group compared with that in the mild keratoconus group (median, interquartile range: 1.09; 0.60-19.66 vs. 0.51; 0.39-1.51 g/mm, P = 0.035). In bivariate correlations, reduced corneal sensitivity in keratoconus was associated with age (ρ = 0.42, P = 0.040), disease duration (ρ = 0.49, P = 0.015) and severity (ρ = 0.44; P = 0.032), lower central nerve fiber density (ρ = -0.68, P = 0.014), contact lens wear (ρ = 0.44; P = 0.025), and contact lens tolerance (ρ = 0.46; P = 0.033). After adjusting for contact lens wear, reduced corneal sensitivity was negatively associated with ocular symptoms (ρ = -0.426, P = 0.048) and pain sensitivity (ρ = -0.423, P = 0.045) and positively associated with corneal staining (ρ = 0.52, P = 0.011). Altered corneal sensitivity in keratoconus affected ocular symptoms and ocular surface health, which may have significant impact on the success of management options for keratoconus.

  2. [The use of iontophoresis in corneal crosslinking technique].

    Science.gov (United States)

    Stanca, Horia T; Tabacaru, Bogdana

    2013-01-01

    Iontophoresis is a method of facilitating the penetration of a drug through an intact tissue in the presence of an low intensity electrical current. In corneal crosslinking technique, iontophoresis is used for transepitelial impregnation of cornea with riboflavin. Compared to passive technique of corneal impregnation, iontophoresis shortens the time needed for impregnation, the time of exposure to UVA radiation and does not require de-epithelialisation.

  3. On fractional Bessel equation and the description of corneal topography

    CERN Document Server

    Okrasiński, Wojciech

    2012-01-01

    In this note we apply a modified fractional Bessel differential equation to the problem of describing corneal topography. We find the solution in terms of the power series. This solution has an interesting behavior at infinity which is a generalization of the classical results for modified Bessel function of order 0. Our model fits the real corneal geometry data with an error of order of a few per cent.

  4. ROLE OF CORNEAL COLLAGEN CROSS LINKING IN KERATOCONUS

    OpenAIRE

    Atul; Superna; Bhimasankar; Vijayleela

    2015-01-01

    To evaluate the outcome of collagen cross linkage using riboflavin 0.1% and ultraviolet A radiation of a wavelength 370nm . PURPOSE : To determine the effect of collagen cross linking for keratoconus on pachymetry , corneal topography, uncorrected visual acuity, specular count, IOP at 1, 3, 6 months . METHODS : The current study was designed as a prospective interventional trial of corneal collagen cross - linking in subjects w...

  5. Hypertonic saline in the treatment of corneal jellyfish stings.

    Science.gov (United States)

    Yu Yao, Hsin; Cho, Ta Hsiung; Lu, Ching Hsiang; Lin, Feng Chi; Horng, Chi Ting

    2016-02-01

    A 20-year-old male soldier was hit by the jellyfish. The ophthalmic examination revealed that epithelial keratitis and corneal oedema in the right eye. We prescribed 3% NaCl eyedrops and 0.3% Norfloxacin eyedrops in the treatment of the corneal jellyfish stings. Two weeks later, the cornea in the right eye healed. In this case report, 3% NaCl eyedrops was effective in the treatment of acute phase of jellyfish stings of the cornea.

  6. Morphometrics of corneal growth in chicks raised in constant light.

    Science.gov (United States)

    Wahl, Christina; Li, Tong; Choden, Tsering; Howland, Howard

    2009-03-01

    In this study we wish to augment our understanding of the effect of environment on corneal growth and morphology. To understand how corneal development of chicks raised in constant light differs from that of 'normal' eyes exposed to cyclic periods of light and dark, white Leghorn chicks were raised under either constant light (approximately 700 lux at cage top) or in 12 h light/12 h dark conditions for up to 12 weeks after hatching. To determine whether corneal expansion is uniform, some birds from each group received corneal tattoos for periodic photographic assessment. By 16 days of age, constant light corneas weighed less than light/dark regimen corneas [7.39 +/- 0.35 mg (SE) vs. 8.47 mg +/- 0.26 mg SE wet weight, P < or = 0.05], and corresponding differences were seen in corneal dry weights. Spatial expansion of the corneal surface was uniform in both groups, but the rate of expansion was slower in constant light chicks [0.0327 +/- 0.009 (SE) vs. 0.144 +/- 0.018 (SE) mm(2) day(-1) for normal chicks, P < or = 0.001]. At 1 day of age, there were 422 +/- 12.5 (SE) stromal cells 0.01 mm(-2) in the central cornea and 393 +/- 21.5 (SE) stromal cells 0.01 mm(-2 )peripherally. Although this difference is not statistically significant, the cell densities in the central cornea were always larger than those of the peripheral cornea in all eight measurements over a 10.5-week period, and this difference is significant (P < or = 0.008, binomial test). Light/dark regimen birds show no such consistent difference in cell densities between central and peripheral corneas. Thus, the density distribution of corneal stromal cells of chicks grown in constant light differs from that of normal chicks. Taken together, all these observations suggest that diurnal cycles of light and darkness are necessary for normal corneal growth.

  7. Electrically assisted delivery of macromolecules into the corneal epithelium

    OpenAIRE

    HAO, JINSONG; Li, S. Kevin; Liu, Chia-Yang; Kao, Winston W. Y.

    2009-01-01

    Electrically assisted delivery is noninvasive and has been investigated in a number of ocular drug delivery studies. The objectives of this study were to examine the feasibility of electrically assisted delivery of macromolecules such as small interfering RNA (siRNA) into the corneal epithelium, to optimize the iontophoresis and electroporation methods, and to study the mechanisms of corneal iontophoresis for macromolecules. Anodal and cathodal iontophoresis, electroporation and their combina...

  8. Preparation and characterization of hydroxyapatite/gelatin composite membranes for immunoisolation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jyh-Ping, E-mail: jpchen@mail.cgu.edu.tw [Department of Chemical and Materials Engineering, Chang Gung University, 259 Wen Hwa 1st Rd., Kwei-San, Taoyuan 333, Taiwan (China); Chang, Feng-Nian [Department of Chemical and Materials Engineering, Chang Gung University, 259 Wen Hwa 1st Rd., Kwei-San, Taoyuan 333, Taiwan (China)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Cross-linking gelatin in the presence of hydroxyapatite forms composite membranes. Black-Right-Pointing-Pointer The membrane was used for immunoisolation and encapsulation of cells. Black-Right-Pointing-Pointer Encapsulated islet cells secrete insulin in response to glucose concentrations. Black-Right-Pointing-Pointer The membrane is a good candidate for bioartificial pancreas development. - Abstract: Composite membranes are fabricated from hydroxyapatite (HAP) and gelatin for immunoisolation of cells. The films were fabricated by crosslinking 5 wt%, 10 wt%, and 20 wt% gelatin with 1 wt% glutaraldehyde (GA) in the presence of HAP. Fourier transform infrared spectroscopy analysis confirms imide bond formation between GA and gelatin, while the crystal structure of HAP powder remains unchanged from X-ray diffraction analysis. The degree of crosslinking depends on crosslinking time and gelatin concentration. For 5% and 10% gelatin, the degree of crosslinking levels off at 90% within 48 h. From scanning electron microscopy micrographs, the microstructure of the composite membrane depends on the amount of gelatin used in the crosslinking reaction. The mechanical strength of the composite membrane could be enhanced by increasing the gelatin concentration. BET analysis indicates that pore size of the micropores on the surface HAP/gelatin agglomerates decreases with increasing gelatin concentration. However, the macropore, through which diffusion of molecules occurs, is larger at higher gelatin concentrations. The permeability coefficients of different molecules through a HAP/gelatin composite membrane increase with increasing gelatin concentration and is inversely correlated with the molecular weight of the molecule. For immunoisolation of cells, the diffusion of large molecules stimulated by the immune system can be rejected by a chamber constructed from the HAP/gelatin membrane. Insulinoma cells were encapsulated in alginate

  9. Characterization of edible film fabricated with channel catfish (Ictalurus punctatus) gelatin extract using selected pretreatment methods.

    Science.gov (United States)

    Zhang, S; Wang, Y; Herring, J L; Oh, J-H

    2007-11-01

    Farm-raised catfish are important to the economy of the southeastern states in the United States, and catfish processing produces about 55% of by-products for inexpensive sale. Therefore, the utilization of catfish by-products is of great interest to the catfish industry. The objectives of this research were to determine the optimum pretreatment method to extract catfish gelatin for edible film application, and to characterize physical, mechanical, and barrier properties of edible films fabricated with catfish skin gelatin. Catfish skins obtained from a local plant were treated with 6 selected pretreatment methods. The main extraction was performed with deionized water at 50 degrees C after pretreatment. The gelatin yield was calculated and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to characterize molecular weight (MW) profile. Color, tensile strength (TS), elongation, and water barrier property were determined to characterize the fabricated catfish gelatin films. From the results of gelatin yield, color, SDS-PAGE, as well as mechanical and barrier properties of the film, the pretreatment method with 0.25 M NaOH and 0.09 M acetic acid, followed by extraction at 50 degrees C for 3 h, was determined as the optimum extraction method. The catfish gelatin exhibited higher MW fractions than commercial mammalian gelatin. The catfish gelatin extracts possessed film-forming properties determined by TS, elongation, and water vapor permeability (WVP) comparable to those of commercial mammalian gelatin. The selected formula for catfish gelatin film was determined as 1% gelatin and 20% glycerol, resulting in greatest TS and lowest WVP.

  10. Corneal Cell Morphology in Keratoconus: A Confocal Microscopic Observation

    Science.gov (United States)

    Ghosh, Somnath; Mutalib, Haliza Abdul; Kaur, Sharanjeet; Ghoshal, Rituparna; Retnasabapathy, Shamala

    2017-01-01

    Purpose To evaluate corneal cell morphology in patients with keratoconus using an in vivo slit scanning confocal microscope. Methods A cross-sectional study was conducted to evaluate the corneal cell morphology of 47 keratoconus patients and 32 healthy eyes without any ocular disease. New keratoconus patients with different disease severities and without any other ocular co-morbidity were recruited from the ophthalmology department of a public hospital in Malaysia from June 2013 to May 2014. Corneal cell morphology was evaluated using an in vivo slit-scanning confocal microscope. Qualitative and quantitative data were analysed using a grading scale and the Nidek Advanced Visual Information System software, respectively. Results The corneal cell morphology of patients with keratoconus was significantly different from that of healthy eyes except in endothelial cell density (P = 0.072). In the keratoconus group, increased level of stromal haze, alterations such as the elongation of keratocyte nuclei and clustering of cells at the anterior stroma, and dark bands in the posterior stroma were observed with increased severity of the disease. The mean anterior and posterior stromal keratocyte densities and cell areas among the different stages of keratoconus were significantly different (P 0.05) among the three stages of keratoconus. Conclusion Confocal microscopy observation showed significant changes in corneal cell morphology in keratoconic cornea from normal healthy cornea. Analysis also showed significant changes in different severities of keratoconus. Understanding the corneal cell morphology changes in keratoconus may help in the long-term monitoring and management of keratoconus. PMID:28894403

  11. Corneal pain activates a trigemino-parabrachial pathway in rats.

    Science.gov (United States)

    Aicher, Sue A; Hegarty, Deborah M; Hermes, Sam M

    2014-03-06

    Corneal pain is mediated by primary afferent fibers projecting to the dorsal horn of the medulla, specifically the trigeminal nucleus caudalis. In contrast to reflex responses, the conscious perception of pain requires transmission of neural activity to higher brain centers. Ascending pain transmission is mediated primarily by pathways to either the thalamus or parabrachial nuclei. We previously showed that some corneal afferent fibers preferentially contact parabrachial-projecting neurons in the rostral pole of the trigeminal nucleus caudalis, but the role of these projection neurons in transmitting noxious information from the cornea has not been established. In the present study, we show that noxious stimulation of the corneal surface activates neurons in the rostral pole of the nucleus caudalis, including parabrachially projecting neurons that receive direct input from corneal afferent fibers. We used immunocytochemical detection of c-Fos protein as an index of neuronal activation after noxious ocular stimulation. Animals had previously received injections of a retrograde tracer into either thalamic or parabrachial nuclei to identify projection neurons in the trigeminal dorsal horn. Noxious stimulation of the cornea induced c-Fos in neurons sending projections to parabrachial nuclei, but not thalamic nuclei. We also confirmed that corneal afferent fibers identified with cholera toxin B preferentially target trigeminal dorsal horn neurons projecting to the parabrachial nucleus. The parabrachial region sends ascending projections to brain regions involved in emotional and homeostatic responses. Activation of the ascending parabrachial system may explain the extraordinary salience of stimulation of corneal nociceptors.

  12. Analysis of corneal esthesia in patients undergoing photorefractive keratectomy

    Directory of Open Access Journals (Sweden)

    Elmar Torres Neto

    2015-12-01

    Full Text Available ABSTRACT Purpose: To quantitatively analyze corneal esthesia in patients undergoing photorefractive keratectomy (PRK surgery. Methods: Forty-five patients selected for PRK in one eye underwent corneal esthesia using a Cochet-Bonnet esthesiometer preoperatively and 30 and 90 days postoperatively. Patients with a refractive diopter error of 4 or greater received intraoperative 0.02% mitomycin C for 20 s. Results: Twenty-four (53.3% of the 45 eyes received intraoperative 0.02% mitomycin. Decreased sensitivity was observed on postoperative day 30. By postoperative day 90, corneal esthesia had normalized but remained 14.9% lower than preoperative levels. In the mitomycin group, no recovery of corneal esthesia to normal sensitivity levels was observed. The mean esthesiometer level was 39.2 mm on postoperative day 90 (P<0.001. Conclusions: The results of the present study demonstrate recovery of corneal esthesia to normal levels at 90 days postoperatively in patients who did not receive mitomycin C. In patients administered mitomycin C, a 23.59% reduction in the corneal touch threshold was observed compared with preoperative levels indicating a failure of recovery to normal levels.

  13. Congenital Corneal Anesthesia and Neurotrophic Keratitis: Diagnosis and Management

    Directory of Open Access Journals (Sweden)

    Flavio Mantelli

    2015-01-01

    Full Text Available Neurotrophic keratitis (NK is a rare degenerative disease of the cornea caused by an impairment of corneal sensory innervation, characterized by decreased or absent corneal sensitivity resulting in epithelial keratopathy, ulceration, and perforation. The aetiopathogenesis of corneal sensory innervation impairment in children recognizes the same range of causes as adults, although they are much less frequent in the pediatric population. Some extremely rare congenital diseases could be considered in the aetiopathogenesis of NK in children. Congenital corneal anesthesia is an extremely rare condition that carries considerable diagnostic and therapeutic problems. Typically the onset is up to 3 years of age and the cornea may be affected in isolation or the sensory deficit may exist as a component of a congenital syndrome, or it may be associated with systemic somatic anomalies. Accurate diagnosis and recognition of risk factors is important for lessening long-term sequelae of this condition. Treatment should include frequent topical lubrication and bandage corneal or scleral contact lenses. Surgery may be needed in refractory cases. The purpose of this review is to summarize and update data available on congenital causes and treatment of corneal hypo/anesthesia and, in turn, on congenital NK.

  14. Corneal organ cultures in tyrosinemia release chemotactic factors.

    Science.gov (United States)

    Lohr, K M; Hyndiuk, R A; Hatchell, D L; Kurth, C E

    1985-05-01

    Corneal inflammation with subsequent scarring and blindness occurs in the inherited human metabolic disease tyrosinemia type II, yet putative inflammatory mediators in this disorder and in the avascular cornea in general are poorly defined. In a Tyr-fed rat model of tyrosinemia type II, intracellular crystals, presumably Tyr, are hypothesized to be responsible for the increased lysosomal activity observed in corneal epithelial lesions. Because polymorphonuclear leukocytes (PMNs) are seen only at the site of these lesions, we used this model to study humoral mediators released from Tyr-fed rat corneal organ cultures. Only Tyr-fed rats developed stromal edema and linear granular opacities in gray edematous corneal epithelium, compatible with a noninfectious keratitis. Electron micrographs confirmed epithelial edema and showed focal epithelial necrosis with PMN invasion of the stroma. Only Tyr-fed rat corneal culture supernatants contained chemotactic activity that was heat labile and moderately trypsin sensitive. Four peaks with varying amounts of chemotactic activity were found on Sephadex G-75 chromatography. Although the identity of these peaks of activity has not yet been established, we suggest that they may be responsible for the PMN infiltration observed in this model of corneal inflammation.

  15. Corneal lesion as the initial manifestation of tyrosinemia type II.

    Science.gov (United States)

    Tsai, Chun-Pin; Lin, Pei-Yu; Lee, Ni-Chung; Niu, Dau-Ming; Lee, Shui-Mei; Hsu, Wen-Ming

    2006-06-01

    Tyrosinemia type II (Richner-Hanhart syndrome) is a rare autosomal recessive disease with deficiency of tyrosine aminotransferase and subsequently increasing level of serum tyrosine. We report the case of a 2-year-old girl who was referred due to bilateral corneal lesions. Slit-lamp examination showed small granular white deposits arranged in a dendritic pattern in the superficial central cornea of both eyes. Physical examination revealed painful, non-pruritic, hyperkeratotic plaques on the soles, palms and fingertips. Mental evaluation demonstrated developmental delay for her age. Blood examination revealed serum tyrosine level to be 1868 microM (normal range, 30-110 microM), which decreased to 838 microM with 2-month diet on tyrosine and phenylalanine restriction. The corneal and skin lesions resolved completely. However, the corneal deposits recurred a month later as her mother failed to strictly control the diet because the little girl was losing weight and activity. With specific formula and adjusted diet regimen, the corneal lesions decreased again. Corneal pseudodendritic deposits may be the initial manifestation in patients with tyrosinemia type II. Early diagnosis and intervention with diet control are crucial for preventing permanent visual and developmental deficits. Corneal deposits can be one of the parameters in monitoring the efficacy of diet control.

  16. Azithromycin (AZM) treatment increases survival of high risk corneal allotransplants

    Science.gov (United States)

    Medina, Carlos A.; Rowe, Alexander M.; Yun, Hongmin; Knickelbein, Jared E.; Lathrop, Kira L.; Hendricks, Robert L.

    2012-01-01

    Purpose To test the therapeutic efficacy of AZM, a macrolide antibiotic for prolonging murine “high risk” corneal allograft survival. Methods Fully MHC mismatched corneas were transplanted from C57BL/6 donors to BALB/c recipients with suture-induced vascularized “high risk” corneal beds. Recipient mice were either not treated or treated with topical AZM, oral AZM, or both. Evaluation of graft vascularization and clarity was performed in masked fashion. Lymph nodes were excised and analyzed for CD4, FoxP3, and CD44 by flow cytometry; and for T cell priming by proliferation and cytokine production in mixed lymphocyte cultures. Corneal whole mounts were evaluated by confocal microscopy. Results The incidence of graft rejection in the control group (81.8%) was significantly reduced by AZM treatment (18.2% topical, 21.7% oral, 33.3% topical + oral), although corneal vascularization was not affected by treatment. The frequency of corneas that retained complete clarity following transplantation was higher in the AZM treated groups. Reduced graft rejection in the AZM treated groups was not associated with a reduced allospecific T cell response or increased frequency of T regulatory cells. Conclusions AZM is effective in prolonging survival of “high risk” corneal allografts by an as yet undefined mechanism that does not appear to involve modulation of corneal neovascularization or allo-specific T cell priming. PMID:23407315

  17. Limbal stem cells: Central concepts of corneal epithelial homeostasis

    Institute of Scientific and Technical Information of China (English)

    Jinny; J; Yoon; Salim; Ismail; Trevor; Sherwin

    2014-01-01

    A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal surface

  18. Corneal Complications And Visual Impairment In Vernal Keratoconjunctivitis Patients.

    Science.gov (United States)

    Arif, Abdus Salam; Aaqil, Bushra; Siddiqui, Afsheen; Nazneen, Zainab; Farooq, Umer

    2017-01-01

    Vernal kerato-conjunctivitis (VKC) is an infrequent but serious form of allergic conjunctivitis common in warm and humid areas where air is rich in allergens. It affects both eyes asymmetrically. Although VKC is a self-limiting disease but visions affecting corneal complications influence the quality of life in school children. The aim of this study was to list the corneal complications due to this condition and to find out the extent of visual impairment among VKC patients. This cross-sectional study was conducted in the department of Ophthalmology, Benazir Bhutto Shaheed Hospital on 290 eyes of diagnosed cases of VKC. The diagnosis of VKC was made on the basis of history and examination. Visual acuity was recorded using Snellen's notation and visual impairment was classified according to World Health Organization classification for visual disabilities. The mean age of presentation was 10.83±6.13 years. There were 207 (71.4%) males and 83 (28.6%) females. Corneal scarring was observed in 59 (20.3%) eyes. Keratoconus was found to be in 17 (5.9%) eyes. Shield ulcer was detected in 09 (3.1%) eyes while 07 (2.4%) eyes had corneal neovascularization. Majority of the patients with visual loss had corneal scarring and the complication that led to severe visual loss in most of the eyes was Keratoconus. Vernal kerato-conjunctivitis in the presence of corneal complications is a sight threatening disease and can lead to severe visual impairment.

  19. Inhibition of Corneal Neovascularization by Topical and Subconjunctival Tigecycline

    Directory of Open Access Journals (Sweden)

    Sertan Goktas

    2014-01-01

    Full Text Available Objective. To investigate the effects of topical and subconjunctival tigecycline on the prevention of corneal neovascularization. Materials and Methods. Following chemical burn, thirty-two rats were treated daily with topical instillation of 1 mg/mL tigecycline (group 1 or subconjunctival instillation of 1 mg/mL tigecycline (group 3 for 7 days. Control rats received topical (group 2 or subconjunctival (group 4 0.9% saline. Digital photographs of the cornea were taken on the eighth day after treatment and analyzed to determine the percentage area of the cornea covered by neovascularization. Corneal sections were analyzed histopathologically. Results. The median percentages of corneal neovascularization in groups 1 and 3 were 48% (95% confidence interval (CI, 44.2–55.8% and 33.5% (95% CI, 26.6–39.2%, respectively. The median percentages of corneal neovascularization of groups 1 and 3 were significantly lower than that of the control group (P=0.03 and P<0.001, resp.. Histologic examination of samples from groups 1 and 3 showed lower vascularity than that of control groups. Conclusion. Topical and subconjunctival administration of tigecycline seems to be showing promising therapeutic effects on the prevention of corneal neovascularization. Furthermore, subconjunctival administration of tigecycline is more potent than topical administration in the inhibition of corneal neovascularization.

  20. The Study of Corneal Topography in Myopic and Hyperopic Children

    Institute of Scientific and Technical Information of China (English)

    Lei Gao; Xuying Zhuo; Lusheng Ma; Ning Yu; Zhonghao Wang; Pengfei Jiang

    2005-01-01

    Purpose: To compare the differences of corneal topographies in myopic and hyperopic children and study the effect of Atropin on their changes.Methods: The refractive components of 136 eyes with different refractive conditions were measured with A-Scan and their corneal topographies with and without cycloplegia were obtained respectively.Results: The mean corneal power of zones 3mm (MD3, P=0.031 ) and minor keratometer K2 (P=0.003) of myopia are greater than those of hyperopia without cycloplegia. MD3 (P=0.009) and Keratometer K1 (P = 0.025) increased in hyperopic eyes, while MD3(P=0.033), K1 (P = 0.035) and K2 (P = 0.002) decreased in myopic eyes significantly after cycloplegia. Similarly, the mean corneal power of zones 5mm (MD5) and 7mm (MD7) in myopic eyes decreased dramatically (P ≤ 0.001 ).Conclusions: The corneal power was found to be greater in myopia than that in hyperopia. The effect of Atropin on corneal shape of myopia and hyperopia was in the opposite direction.

  1. Corneal confocal sub-basal nerve plexus evaluation: a review.

    Science.gov (United States)

    Kokot, Joanna; Wylęgała, Adam; Wowra, Bogumił; Wójcik, Łukasz; Dobrowolski, Dariusz; Wylęgała, Edward

    2017-07-25

    The aim of this study was to review the most recent data about corneal sub-basal nerve plexus (SNP) evaluated with the use of corneal confocal microscopy (CCM). For this purpose, an electronic search was conducted based on PubMed and Google Scholar and Web of Science databases from 2008 up to the end of 2016. Ninety-eight articles in English were cited, as well as abstracts in other languages, concerning the morphology and function of corneal SNP in various diseases. Changes in corneal SNP as a result of local treatment were also introduced. Figures with scans from confocal microscopy from our Department were included. The main conclusion of this review was that both corneal SNP diminishment and high tortuosity as well as low sensitivity are in principle related to the presence or level of pathology. In addition, increased nerve tortuosity may represent a morphological determinant of nerve regeneration. However, the presented literature shows that SNP changes are not characteristic for one unified corneal pathology; rather, they reflect the non-specific pathological process present in many diseases. Future studies should use automatized biometric software and also examine the effects of new treatments on SNP. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  2. Effect of substrate composition and alignment on corneal cell phenotype.

    Science.gov (United States)

    Phu, Donna; Wray, Lindsay S; Warren, Robert V; Haskell, Richard C; Orwin, Elizabeth J

    2011-03-01

    Corneal blindness is a significant problem treated primarily by corneal transplants. Donor tissue supply is low, creating a growing need for an alternative. A tissue-engineered cornea made from patient-derived cells and biopolymer scaffold materials would be widely accessible to all patients and would alleviate the need for donor sources. Previous work in this lab led to a method for electrospinning type I collagen scaffolds for culturing corneal fibroblasts ex vivo that mimics the microenvironment in the native cornea. This electrospun scaffold is composed of small-diameter, aligned collagen fibers. In this study, we investigate the effect of scaffold nanostructure and composition on the phenotype of corneal stromal cells. Rabbit-derived corneal fibroblasts were cultured on aligned and unaligned collagen type I fibers ranging from 50 to 300 nm in diameter and assessed for expression of α-smooth muscle actin, a protein marker upregulated in hazy corneas. In addition, the optical properties of the cell-matrix constructs were assessed using optical coherence microscopy. Cells grown on collagen scaffolds had reduced myofibroblast phenotype expression compared to cells grown on tissue culture plates. Cells grown on aligned collagen type I fibers downregulated α-smooth muscle actin protein expression significantly more than unaligned collagen scaffolds, and also exhibited reduced overall light scattering by the tissue construct. These results suggest that aligned collagen type I fibrous scaffolds are viable platforms for engineering corneal replacement tissue.

  3. Acacia honey accelerates in vitro corneal ulcer wound healing model.

    Science.gov (United States)

    Abd Ghafar, Norzana; Ker-Woon, Choy; Hui, Chua Kien; Mohd Yusof, Yasmin Anum; Wan Ngah, Wan Zurinah

    2016-07-29

    The study aimed to evaluate the effects of Acacia honey (AH) on the migration, differentiation and healing properties of the cultured rabbit corneal fibroblasts. Stromal derived corneal fibroblasts from New Zealand White rabbit (n = 6) were isolated and cultured until passage 1. In vitro corneal ulcer was created using a 4 mm corneal trephine onto confluent cultures and treated with basal medium (FD), medium containing serum (FDS), with and without 0.025 % AH. Wound areas were recorded at day 0, 3 and 6 post wound creation. Genes and proteins associated with wound healing and differentiation such as aldehyde dehydrogenase (ALDH), vimentin, alpha-smooth muscle actin (α-SMA), collagen type I, lumican and matrix metalloproteinase 12 (MMP12) were evaluated using qRT-PCR and immunocytochemistry respectively. Cells cultured with AH-enriched FDS media achieved complete wound closure at day 6 post wound creation. The cells cultured in AH-enriched FDS media increased the expression of vimentin, collagen type I and lumican genes and decreased the ALDH, α-SMA and MMP12 gene expressions. Protein expression of ALDH, vimentin and α-SMA were in accordance with the gene expression analyses. These results demonstrated AH accelerate corneal fibroblasts migration and differentiation of the in vitro corneal ulcer model while increasing the genes and proteins associated with stromal wound healing.

  4. Studies on the particle size control of gelatin microspheres

    Institute of Scientific and Technical Information of China (English)

    Ruixue SUN; Jingjing SHI; Yanchuan GUO; Lijuan CHEN

    2009-01-01

    A series of gelatin microspheres (GMs) were prepared through emulsification-coacervation method in water-in-oil (w/o) emulsions. The influence of preparation parameters on particle size, surface morphology, and dispersion of GMs was examined. The studied preparation parameters include concentration of gelatin solutions, concentration of the emulsifier, w/o ratio, emulsifying time, stirring speed, and so on. The surface morphology, dispersion, and particle sizes of GMs were determined by the scanning electron microscopy (SEM), SemAfore 4 Demo software, and particle size distribution graphic charts. The experimental results indicated that increasing the concentration of gelatin solution would increase the particle size of GMs. When the solution concentration increased from 0.050 to 0.200 g/mL gradually, the particle size increased correspondingly. The relationship between the two quantities was linear. On the contrary, increasing the concentration of the emulsifier would decrease the particle size of GMs. Furthermore, the particle size reduced quickly at initial time and slowed down latterly. With the increase of emulsifier concentration from 0 to 0.020 g/mL, the mean diameters of GMs decreased from 17.32 to 5.38 urn. However, the particle size dwindled slowly when emulsifier concentration was higher than 0.020 g/mL. The excellent result was obtained with the condition of 0.050 g/mL of emulsifier concentration, 0.100 g/mL of gelatin solution concentration, 1/5 of w/o ratio, 10 min of emulsifying time, and 900 r/min of the stirring speed. The GMs prepared at this condition had the smallest sizes, the narrowest size distribution, the best spherical shape, and fluidity. The w/o ratio has the same influence on particle size of GMs as that of gelatin solution concentration. With the increase of w/o ratio, the average particle sizes increased linearly, and the surface of microspheres become smoother as well. It is supposed that w/o ratio can be used to change the diameters

  5. Preparation of arginine–glycine–aspartic acid-modified biopolymeric nanoparticles containing epigalloccatechin-3-gallate for targeting vascular endothelial cells to inhibit corneal neovascularization

    Science.gov (United States)

    Chang, Che-Yi; Wang, Ming-Chen; Miyagawa, Takuya; Chen, Zhi-Yu; Lin, Feng-Huei; Chen, Ko-Hua; Liu, Guei-Sheung; Tseng, Ching-Li

    2017-01-01

    Neovascularization (NV) of the cornea can disrupt visual function, causing ocular diseases, including blindness. Therefore, treatment of corneal NV has a high public health impact. Epigalloccatechin-3-gallate (EGCG), presenting antiangiogenesis effects, was chosen as an inhibitor to treat human vascular endothelial cells for corneal NV treatment. An arginine–glycine–aspartic acid (RGD) peptide–hyaluronic acid (HA)-conjugated complex coating on the gelatin/EGCG self-assembly nanoparticles (GEH-RGD NPs) was synthesized for targeting the αvβ3 integrin on human umbilical vein endothelial cells (HUVECs) in this study, and a corneal NV mouse model was used to evaluate the therapeutic effect of this nanomedicine used as eyedrops. HA-RGD conjugation via COOH and amine groups was confirmed by 1H-nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The average diameter of GEH-RGD NPs was 168.87±22.5 nm with positive charge (19.7±2 mV), with an EGCG-loading efficiency up to 95%. Images of GEH-RGD NPs acquired from transmission electron microscopy showed a spherical shape and shell structure of about 200 nm. A slow-release pattern was observed in the nanoformulation at about 30% after 30 hours. Surface plasmon resonance confirmed that GEH-RGD NPs specifically bound to the integrin αvβ3. In vitro cell-viability assay showed that GEH-RGD efficiently inhibited HUVEC proliferation at low EGCG concentrations (20 μg/mL) when compared with EGCG or non-RGD-modified NPs. Furthermore, GEH-RGD NPs significantly inhibited HUVEC migration down to 58%, lasting for 24 hours. In the corneal NV mouse model, fewer and thinner vessels were observed in the alkali-burned cornea after treatment with GEH-RGD NP eyedrops. Overall, this study indicates that GEH-RGD NPs were successfully developed and synthesized as an inhibitor of vascular endothelial cells with specific targeting capacity. Moreover, they can be used in eyedrops to inhibit angiogenesis in corneal NV

  6. Preparation of arginine-glycine-aspartic acid-modified biopolymeric nanoparticles containing epigalloccatechin-3-gallate for targeting vascular endothelial cells to inhibit corneal neovascularization.

    Science.gov (United States)

    Chang, Che-Yi; Wang, Ming-Chen; Miyagawa, Takuya; Chen, Zhi-Yu; Lin, Feng-Huei; Chen, Ko-Hua; Liu, Guei-Sheung; Tseng, Ching-Li

    2017-01-01

    Neovascularization (NV) of the cornea can disrupt visual function, causing ocular diseases, including blindness. Therefore, treatment of corneal NV has a high public health impact. Epigalloccatechin-3-gallate (EGCG), presenting antiangiogenesis effects, was chosen as an inhibitor to treat human vascular endothelial cells for corneal NV treatment. An arginine-glycine-aspartic acid (RGD) peptide-hyaluronic acid (HA)-conjugated complex coating on the gelatin/EGCG self-assembly nanoparticles (GEH-RGD NPs) was synthesized for targeting the αvβ3 integrin on human umbilical vein endothelial cells (HUVECs) in this study, and a corneal NV mouse model was used to evaluate the therapeutic effect of this nanomedicine used as eyedrops. HA-RGD conjugation via COOH and amine groups was confirmed by (1)H-nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The average diameter of GEH-RGD NPs was 168.87±22.5 nm with positive charge (19.7±2 mV), with an EGCG-loading efficiency up to 95%. Images of GEH-RGD NPs acquired from transmission electron microscopy showed a spherical shape and shell structure of about 200 nm. A slow-release pattern was observed in the nanoformulation at about 30% after 30 hours. Surface plasmon resonance confirmed that GEH-RGD NPs specifically bound to the integrin αvβ3. In vitro cell-viability assay showed that GEH-RGD efficiently inhibited HUVEC proliferation at low EGCG concentrations (20 μg/mL) when compared with EGCG or non-RGD-modified NPs. Furthermore, GEH-RGD NPs significantly inhibited HUVEC migration down to 58%, lasting for 24 hours. In the corneal NV mouse model, fewer and thinner vessels were observed in the alkali-burned cornea after treatment with GEH-RGD NP eyedrops. Overall, this study indicates that GEH-RGD NPs were successfully developed and synthesized as an inhibitor of vascular endothelial cells with specific targeting capacity. Moreover, they can be used in eyedrops to inhibit angiogenesis in corneal NV mice.

  7. SCAFFOLD BHA/GELATIN DENGAN PELAPIS PVA UNTUK APLIKASI IMPLAN

    Directory of Open Access Journals (Sweden)

    Alva Edy Tontowi, MK Herliansyah, dan Punto Dewo

    2013-12-01

    Full Text Available Hard tissue defect, particularly at the bone structure, is a common problem in Indonesia causing improper function. About 60% of it is caused by defects that occur since birth, and the rest is caused by other factors, such as accidents. To treat these problems, medical doctor usually carry out transplantation or implantation. Implantation is done by filling the bone cavity with biomaterial made from Ca/P-based material, such as hydroxyapatite (HA. In the form of powder, pure HA is difficult to be formed into a certain shape and geometry since this material is brittle and has a high melting point (1400 oc, which is impossible to reach in a surgery environment. Additionally, in the form of macro-porous blocks, they are very weak and easy to break, far from the requirements. In order to form pure HA at room temperature and still fulfill the required strength, other biocompatible materials are needed. In this work, HA, gelatin and PVA were used to form samples. The HA was derived from bovine bone, bioactivity and oteoconductivity. Gelatin was used as a matrix of the composite, whilst Polyvynil Alchohol (PVA acted as a coating. The HA was derived by calcination of bovine chips at 900 oC for 2 hours, while the gelatin (G and PVA were supplied by commercial purchase. The ratio of [G/bHA] to distilled water (H2O was 30%, 40% dan 50% w/v. PVA 0.2% w/w coating was done by dipping the block in liquid nitrogen (N2. Tests were performed by DTS and microstructure analysis was carried out by SEM. The results show that sample with [G/bHA] of 50% w/v gave DTS of 6.219 MPa. This tensile strength matched the strength of human bone from a 62 year old person.  

  8. SCAFFOLD BHA/GELATIN DENGAN PELAPIS PVA UNTUK APLIKASI IMPLAN

    Directory of Open Access Journals (Sweden)

    Alva Edy Tontowi, MK Herliansyah, dan Punto Dewo

    2013-12-01

    Full Text Available Hard tissue defect, particularly at the bone structure, is a common problem in Indonesia causing improper function. About 60% of it is caused by defects that occur since birth, and the rest is caused by other factors, such as accidents. To treat these problems, medical doctor usually carry out transplantation or implantation. Implantation is done by filling the bone cavity with biomaterial made from Ca/P-based material, such as hydroxyapatite (HA. In the form of powder, pure HA is difficult to be formed into a certain shape and geometry since this material is brittle and has a high melting point (1400 oc, which is impossible to reach in a surgery environment. Additionally, in the form of macro-porous blocks, they are very weak and easy to break, far from the requirements. In order to form pure HA at room temperature and still fulfill the required strength, other biocompatible materials are needed. In this work, HA, gelatin and PVA were used to form samples. The HA was derived from bovine bone, bioactivity and oteoconductivity. Gelatin was used as a matrix of the composite, whilst Polyvynil Alchohol (PVA acted as a coating. The HA was derived by calcination of bovine chips at 900 oC for 2 hours, while the gelatin (G and PVA were supplied by commercial purchase. The ratio of [G/bHA] to distilled water (H2O was 30%, 40% dan 50% w/v. PVA 0.2% w/w coating was done by dipping the block in liquid nitrogen (N2. Tests were performed by DTS and microstructure analysis was carried out by SEM. The results show that sample with [G/bHA] of 50% w/v gave DTS of 6.219 MPa. This tensile strength matched the strength of human bone from a 62 year old person.  

  9. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    OpenAIRE

    Semra Tiryaki Demir; Mahmut Odabaşı; Mehmet Ersin Oba; Ayşe Burcu Dirim; Efe Can; Orhan Kara

    2014-01-01

    Objectives: Comparison of central corneal thickness (CCT) measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG), 41 patients with ocular hypertension (OHT), and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb) ...

  10. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    Directory of Open Access Journals (Sweden)

    Semra Tiryaki Demir

    2014-08-01

    Full Text Available Objectives: Comparison of central corneal thickness (CCT measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG, 41 patients with ocular hypertension (OHT, and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb corneal topography and ultrasonic pachymetry (Nidek Ultrasonic Pachymetry UP-1000 were used for measurement of CCT. ANOVA (Turkey test was used for variable distribution, paired sample t-test was used for repeated measurements, and the analyses were done by SPSS 20.0. Results: Mean CCT was 558.9±37.2 µm by ultrasonic pachymetry and 553.4±37 µm by corneal topography. There was a significant difference between the two measurements (p0.05. CCT was 555±39.2 µm, 564.3±28.4 µm, and 559.7±41.5 µm by ultrasonic pachymetry in POAG, OHT, and control subjects, respectively; CCT was 550.3±38.3 µm, 558.5±28 µm, and 553.2±42.5 µm by Orbscan II corneal topography in POAG, OHT, and control subjects, respectively. There was a significant linear correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements (r=0.975, p<0.0001. Repeatability of ultrasonic pachymetry for same observer was (ICC value 0.990. Conclusion: There is a significant correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements. These two methods of measurements should not be substituted for each other, since ultrasonic pachymetry measures CCT greater than Orbscan II corneal topography. Repeatability of ultrasonic pachymetry for same observer is very high. (Turk J Ophthalmol 2014; 44: 263-7

  11. Concentration-temperature superposition of helix folding rates in gelatin.

    Science.gov (United States)

    Gornall, J L; Terentjev, E M

    2007-07-13

    Using optical rotation as the primary technique, we have characterized the kinetics of helix renaturation in water solutions of gelatin. By covering a wide range of solution concentrations we identify a universal exponential dependence of folding rate on concentration and quench temperature. We demonstrate a new concentration-temperature superposition of data at all temperatures and concentrations, and build the corresponding master curve. The normalized rate constant is consistent with helix lengthening. Nucleation of the triple helix occurs rapidly and contributes less to the helical onset than previously thought.

  12. Mineralization, biodegradation, and drug release behavior of gelatin/apatite composite microspheres for bone regeneration.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Jo, J.; Wang, H.; Yamamoto, M.; Jansen, J.A.; Tabata, Y.

    2010-01-01

    Gelatin microspheres are well-known for their capacity to release growth factors in a controlled manner, but gelatin microspheres do not calcify in the absence of so-called bioactive substances that induce deposition of calcium phosphate (CaP) bone mineral. This study has investigated if CaP nanocry

  13. Study on encapsulation of chlorine dioxide in gelatin microsphere for reducing release rate.

    Science.gov (United States)

    Ci, Ying; Wang, Lin; Guo, Yanchuan; Sun, Ruixue; Wang, Xijie; Li, Jinyou

    2015-01-01

    This study aims to explore the effects of encapsulation of chlorine dioxide in a hydrophilic biodegradable polymer gelatin to reduce its release rate. An emulsification-coacervation method was adopted. The characterizations of chlorine dioxide-gelatin microspheres were described. Using UV-vis spectrophotometer the λmax of chlorine dioxide was observed at 358 nm. The particle size and distribution of chlorine oxide-gelatin microspheres was measured by a dynamic light scattering (DLS) method, the diameter was (1400~1900) nm. The entrapment of chlorine dioxide-gelatin microspheres was confirmed by IR. The surface morphology, size, and shape of chlorine dioxide-gelatin microspheres were analyzed using Scanning electron microscope (SEM). It showed that the encapsulated microspheres size was around 2000 nm with uniform distribution. The percentage entrapment of chlorine dioxide in the encapsulated samples was about 80~85%. A slow release study of chlorine dioxide from the encapsulated biopolymer (gelatin) in air was also carried out, which showed continuous release up to ten days. It can be concluded that it is possible to make a slow release formulation of ClO2 by entrapped in a hydrophilic biodegradable polymer gelatin. ClO2-gelatin microspheres can stable release low concentration ClO2 gas over an extended period.

  14. Electrospun polyurethane-core and gelatin-shell coaxial fibre coatings for miniature implantable biosensors.

    Science.gov (United States)

    Wang, Ning; Burugapalli, Krishna; Wijesuriya, Shavini; Far, Mahshid Yazdi; Song, Wenhui; Moussy, Francis; Zheng, Yudong; Ma, Yanxuan; Wu, Zhentao; Li, Kang

    2014-03-01

    The aim of this study was to introduce bioactivity to the electrospun coating for implantable glucose biosensors. Coaxial fibre membranes having polyurethane as the core and gelatin as the shell were produced using a range of polyurethane concentrations (2, 4, 6 and 8% wt/v) while keeping gelatin concentration (10% wt/v) constant in 2,2,2-trifluoroethanol. The gelatin shell was stabilized using glutaraldehyde vapour. The formation of core-shell structure was confirmed using transmission/scanning electron microscopy and FTIR. The coaxial fibre membranes showed uniaxial tensile properties intermediate to that of the pure polyurethane and the gelatin fibre membranes. The gelatin shell increased hydrophilicity and glucose transport flux across the coaxial fibre membranes. The coaxial fibre membranes having small fibre diameter (541 nm) and a thick gelatin shell (52%) did not affect the sensor sensitivity, but decreased sensor's linearity in the long run. In contrast, thicker coaxial fibre membranes (1133 nm) having a thin gelatin shell (34%) maintained both sensitivity and linearity for the 84 days of the study period. To conclude, polyurethane-gelatin coaxial fibre membranes, due to their faster permeability to glucose, tailorable mechanical properties and bioactivity, are potential candidates for coatings to favourably modify the host responses to extend the reliable in vivo lifetime of implantable glucose biosensors.

  15. Ligation of pork skin gelatin with glucose moieties affects the junction zones in gelled networks

    NARCIS (Netherlands)

    Baigts Allende, Diana; Jongh, de H.H.J.

    2015-01-01

    This study aims to investigate the role of the ligation of steric moieties on the formation of junction zones during network formation of gelatin gels. The molecular conformational propensities, heat stability and mechanical properties of gradually chemically modified pork skin gelatin have been

  16. Ligation of pork skin gelatin with glucose moieties affects the junction zones in gelled networks

    NARCIS (Netherlands)

    Baigts Allende, Diana; Jongh, de H.H.J.

    2015-01-01

    This study aims to investigate the role of the ligation of steric moieties on the formation of junction zones during network formation of gelatin gels. The molecular conformational propensities, heat stability and mechanical properties of gradually chemically modified pork skin gelatin have been

  17. Gelation, oxygen permeability and mechanical properties of mammalian and fish gelatin films

    Science.gov (United States)

    The objective of this study was to evaluate the gelation, thermal, mechanical and oxygen permeability properties of different mammalian, warm- and cold-water fish gelatin solutions and films. Mammalian gelatin solutions had the highest gel set temperatures, followed by warm-water fish and then cold-...

  18. Utilization of agricultural by-products to supplement gelatin in preparation of products for leather

    Science.gov (United States)

    When polyphenolic-modified gelatin-products were used as fillers, improvements were seen in the subjective properties of the leather. When the treated samples were compared to control samples, there were no significant changes in mechanical properties. Gelatin is in high demand and short supply, a...

  19. Utilization of agricultural by-products to partially replace gelatin in preparation of products for leather

    Science.gov (United States)

    When polyphenolic-modified gelatin-products were used as fillers, improvements were seen in the subjective properties of the leather. When the treated samples were compared to control samples, there were no significant changes in mechanical properties. At the present time, gelatin is in short supp...

  20. Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

    Directory of Open Access Journals (Sweden)

    Liu Ying

    2011-01-01

    Full Text Available Abstract Herein, the generation of gold, silver, and silver–gold (Ag–Au bimetallic nanoparticles was carried out in collagen (gelatin solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV–visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device.

  1. Gelatin Scaffolds with Controlled Pore Structure and Mechanical Property for Cartilage Tissue Engineering.

    Science.gov (United States)

    Chen, Shangwu; Zhang, Qin; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2016-03-01

    Engineering of cartilage tissue in vitro using porous scaffolds and chondrocytes provides a promising approach for cartilage repair. However, nonuniform cell distribution and heterogeneous tissue formation together with weak mechanical property of in vitro engineered cartilage limit their clinical application. In this study, gelatin porous scaffolds with homogeneous and open pores were prepared using ice particulates and freeze-drying. The scaffolds were used to culture bovine articular chondrocytes to engineer cartilage tissue in vitro. The pore structure and mechanical property of gelatin scaffolds could be well controlled by using different ratios of ice particulates to gelatin solution and different concentrations of gelatin. Gelatin scaffolds prepared from ≥70% ice particulates enabled homogeneous seeding of bovine articular chondrocytes throughout the scaffolds and formation of homogeneous cartilage extracellular matrix. While soft scaffolds underwent cellular contraction, stiff scaffolds resisted cellular contraction and had significantly higher cell proliferation and synthesis of sulfated glycosaminoglycan. Compared with the gelatin scaffolds prepared without ice particulates, the gelatin scaffolds prepared with ice particulates facilitated formation of homogeneous cartilage tissue with significantly higher compressive modulus. The gelatin scaffolds with highly open pore structure and good mechanical property can be used to improve in vitro tissue-engineered cartilage.

  2. Gelatinous zooplankton assemblages in temperate coastal waters - seasonal variations (Gulf of Trieste, Adriatic Sea):

    OpenAIRE

    Malej, Alenka; Miloš, Čarna

    2005-01-01

    Gelatinous plankton composition, abundance, biomass and their seasonality was studied in the Gulf of Trieste (Adriatic Sea) over a yearly cycle. The most diversive gelatinous groups were Hydromedusae with 14 species, followed by Siphonophora (six species), Appendicularia (five species), Chaetognatha (two species), and Thaliacea (one species)....

  3. Influence of monoglycerides on the gelatinization and enzymatic breakdown of wheat and cassava starch

    NARCIS (Netherlands)

    Lonkhuysen, H. van; Blankestijn, J.

    1976-01-01

    The influence of monoglycerides on the flocculation and gelatinization of suspensions of wheat starch and cassava starch was studied. The sedimentation volumes of native and gelatinized starch with and without added monoglycerides were measured and the quantity of bound monoglycerides was

  4. Pemisahan krom pada limbah cair industri penyamakan kulit menggunakan gelatin dan flokulan anorganik

    Directory of Open Access Journals (Sweden)

    Sugihartono

    2016-06-01

    Full Text Available ABSTRACT The aim of the study was to determine the ability of gelatin, ferrous sulfate, aluminium sulfate, and combination of gelatin with ferrous sulfate or aluminium sulfate for total chromium content (trivalent chromium and hexavalent chromium separation from tannery wastewater. Reduction of total chromium content in the wastewater was conducted using combination of gelatin and ferrous sulfate or gelatin and aluminium sulfate with a ratio of 4:0; 3:1; 2:2; 1:3; and 0:4 (w/w. The results showed that gelatin, ferrous sulfate, and aluminium sulfate, were able to reduce total chromium content in the wastewater. Combination of gelatin/ferrous sulfate or gelatin/aluminium sulfate as flocculants provide synergistic work in reducing the total chromium content. A 94.75% removal of total chromium content was achieved by combining gelatine and aluminium sulfate with a ratio of 3:1, clearer wastewater, and followed by reduction of degree of turbidity up to 74.47%. The total chromium content after treatment was 0.61 ppm, which met the requirements of wastewater for business and or daily activities especially for tanning industry.

  5. The microstructure and rheology of homogeneous and phase separated gelatine gels

    NARCIS (Netherlands)

    Ersch, C.; Linden, E. van der; Venema, P.; Martin, A.

    2016-01-01

    The gelation of gelatine in mixtures of gelatine (type A or type B) and globular proteins (Whey Protein Isolate (WPI), Whey Protein Aggregates (WPA) and Soy Protein Isolate (SPI)) was studied with a focus on their phase separation during gelation. Confocal laser scanning microscopy, visual observati

  6. The microstructure and rheology of homogeneous and phase separated gelatine gels

    NARCIS (Netherlands)

    Ersch, Carsten; Linden, van der Erik; Venema, Paul; Martin, Anneke

    2016-01-01

    The gelation of gelatine in mixtures of gelatine (type A or type B) and globular proteins (Whey Protein Isolate (WPI), Whey Protein Aggregates (WPA) and Soy Protein Isolate (SPI)) was studied with a focus on their phase separation during gelation. Confocal laser scanning microscopy, visual observ

  7. The formation of light-induced gratings in the rigid eosine K solution in gelatin

    Science.gov (United States)

    Vorob'ev, A. A.; Kolchanova, S. A.; Sizykh, A. G.; Sul'Kis, I. G.

    1992-03-01

    The mechanism of the formation of light-induced amplitude gratings in the rigid eosine K solution in gelatin is investigated. It is shown that spatial modulation of the absorptance of the recording medium is caused by the transformation of the dye into a colorless form in the process of photosensitized proton transfer from gelatin to the eosine.

  8. In vivo compatibility and degradation of crosslinked gelatin gels incorporated in knitted Dacron

    NARCIS (Netherlands)

    Kuijpers, AJ; van Wachem, PB; van Luyn, MJA; Plantinga, JA; Engbers, GHM; Krijgsveld, J; Zaat, SAJ; Feijen, J

    2000-01-01

    Gelatin gels were applied to porous Dacron meshes with the aim of using these gels for local drug delivery. in this article, the biocompatibility and degradation of gelatin gels with different crosslink densities applied in Dacron were studied in vivo by subcutaneous implantation in rats. Dacron dis

  9. In vivo compatibility and degradation of crosslinked gelatin gels incorporated in knitted Dacron

    NARCIS (Netherlands)

    Kuijpers, A.J.; Wachem, van P.B.; Luyn, van M.J.A.; Plantinga, J.A.; Engbers, G.H.M.; Krijgsveld, J.; Zaat, S.A.J.; Dankert, J.; Feijen, J.

    2000-01-01

    Gelatin gels were applied to porous Dacron meshes with the aim of using these gels for local drug delivery. In this article, the biocompatibility and degradation of gelatin gels with different crosslink densities applied in Dacron were studied in vivo by subcutaneous implantation in rats. Dacron dis

  10. Composite gels structured by a gelatin protein matrix filled with oil bodies

    NARCIS (Netherlands)

    Kirimlidou, Miro; Matsakidou, Anthia; Scholten, Elke; Nikiforidis, Constantinos V.; Kiosseoglou, Vassilios

    2017-01-01

    Oil body extracts from sesame seeds and hazelnuts were subjected to centrifugation to recover oil body concentrated creams, which were then suitably diluted with gelatin solutions to prepare mixtures of 25.0. wt% of oil and 2.0-6.0. wt% of gelatin. The gelling behaviour of the mixtures was followed

  11. Antibiotic-releasing porous polymethylmethacrylate/gelatin/antibiotic constructs for craniofacial tissue engineering.

    Science.gov (United States)

    Shi, Meng; Kretlow, James D; Spicer, Patrick P; Tabata, Yasuhiko; Demian, Nagi; Wong, Mark E; Kasper, F Kurtis; Mikos, Antonios G

    2011-05-30

    An antibiotic-releasing porous polymethylmethacrylate (PMMA) construct was developed to maintain the bony space and prime the wound site in the initial step of a two-stage regenerative medicine approach toward reconstructing significant bony or composite craniofacial tissue defects. Porous PMMA constructs incorporating gelatin microparticles (GMPs) were fabricated by the sequential assembly of GMPs, the antibiotic colistin, and a clinically used bone cement formulation of PMMA powder and methylmethacrylate liquid. PMMA/gelatin/antibiotic constructs with varying gelatin incorporation and drug content were investigated to elucidate the relationship between material composition and construct properties (porosity and drug release kinetics). The porosity of PMMA/gelatin/antibiotic constructs ranged between 7.6±1.8% and 38.4±1.4% depending on the amount of gelatin incorporated and the drug solution added for gelatin swelling. The constructs released colistin over 10 or 14 days with an average release rate per day above 10 μg/ml. The porosity and in vitro colistin release kinetics of PMMA/gelatin/antibiotic constructs were tuned by varying the material composition and fabrication parameters. This study demonstrates the potential of gelatin-incorporating PMMA constructs as a functional space maintainer for both promoting tissue healing/coverage and addressing local infections, enabling better long-term success of the definitive regenerated tissue construct. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Effect of high molecular weight plasticizers on the gelatinization of starch under static and shear conditions.

    Science.gov (United States)

    Taghizadeh, Ata; Favis, Basil D

    2013-02-15

    Starch gelatinization in the presence of high molecular weight polyol plasticizers and water was studied under static and dynamic conditions and was compared to a glycerol reference. For static gelatinization, glycerol, sorbitol, diglycerol and polyglycerol were examined using polarized light microscopy and differential scanning calorimetry. A wide range of starch/water/plasticizer compositions were prepared to explore the gelatinization regime for each plasticizer. The plasticizers show that the onset and conclusion temperatures for sorbitol and glycerol are in the same range and are lower than the other two plasticizers. On the other hand, polyglycerol shows a higher gelatinization temperature than diglycerol because of its higher molecular weight and viscosity. The results indicate that in the case of all plasticizers, increasing the water content tends to decrease the gelatinization temperature and, except for polyglycerol, increasing the plasticizer content increases the gelatinization temperature. In the case of polyglycerol, however, increasing the plasticizer content had the opposite effect and this was found to be related to the borderline solubility of polyglycerol in water. When the polyglycerol/water solubility was increased by increasing the temperature of the water/plasticizer/starch slurry, the gelatinization temperature dependence was found to be similar to the other polyols. A rheological technique was developed to study the dynamic gelatinization process by tracking the influence of shear on the complex viscosity in a couette flow system. Glycerol, diglycerol and sorbitol were subjected to different dynamic gelatinization treatments and the results were compared with static gelatinization. It is quantitatively shown that shear has a major effect on the gelatinization process. The conclusion temperature of gelatinization is significantly diminished (up to 21 °C) in the presence of shear whereas the onset temperature of gelatinization remains

  13. Preparation of gelatin-assisted polypyrrole-poly(3,4-ethylenedioxythiophene) composites

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Eun Jin; Male, Umashankar; Huh, Do Sung [Dept.of Chemistry and Nanosystem Engineering, Center for Nano Manufacturing, Inje University, Kimhae (Korea, Republic of)

    2016-11-15

    Conductive polymer composite was synthesized by the polymerization of pyrrole with 3,4-ethylenedioxythiophene using ammonium persulfate as an oxidant with different concentrations of gelatin dispersed in aqueous medium along with the polymerization. Differently from pure polypyrrole–poly(3,4-ethylenedioxythiophene) (PPy–PEDOT) copolymer, the gelatin-assisted composites showed good solubility in aqueous media. The prepared PPy–PEDOT/gelatin composites were identified with Fourier-transform infrared, UV–visible spectroscopy, and X-ray diffraction. Morphological analysis and temperature-dependent direct current conductivity of PPy–PEDOT/gelatin composites were carried out. Obtained results revealed that added gelatin greatly increased conductivity due to the improved mobility of charge carriers.

  14. Genotype diversity in structure of amylopectin of waxy rice and its influence on gelatinization properties.

    Science.gov (United States)

    Lin, Jheng-Hua; Singh, Harinder; Ciao, Jhih-Ying; Kao, Wen-Tzu; Huang, Wei-Hsiang; Chang, Yung-Ho

    2013-02-15

    A set of 13 waxy rice genotypes prepared by chemically-induced mutation of non-waxy rice variety TNG67 and 7 waxy rice varieties widely planted in Taiwan were screened for various structural and gelatinization properties of starches. Wide variation on physicochemical properties and molecular structure of amylopectin for the 20 waxy rice starches were obtained and relationship between gelatinization properties and molecular structure of starch were discussed. More attributes on swelling and gelatinization thermal properties, comparing to pasting attributes, showed significant correlation with molecular structure parameters. The swelling and gelatinization thermal properties of waxy rice starch did not show significant correlation with molecular size of amylopectin, while significant correlations were found between the swelling or gelatinization thermal properties and chain length of amylopectin. Results suggest that the swelling and pasting of waxy starch is essentially dominated by granule architecture and is dependent on the interactions among amylopectin chains. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. [Determination of the gelatinization temperature of starches via thermoanalytical and rheological methods].

    Science.gov (United States)

    Szepes, Aniko; Fehér, András; Eros, István; Szabóné, Révész Piroska

    2007-01-01

    This work provides a short review concerning the measuring techniques frequently applied to characterize the gelatinization behaviour of starches. The aim of the experiments was to determine the gelatinization temperatures of maize (A-type) and potato (B-type) starches via isothermal microcalorimetry and rheological methods (rotational viscosimetry and dynamic oscillatory testing). A significant difference was observed between the gelatinization temperatures of the aqueous starch suspensions, which can be attributed to the structural differences between A-type and B-type starches. Comparison of the applied measuring methods revealed a close correlation between the experimental data obtained by isothermal microcalorimetry and oscillatory testing, while rotational viscosimetry overestimated the gelatinization temperature. Additionally dynamic oscillatory tests provided valuable information not only on the gelatinization point, but also on the pasting temperature of the starch suspensions.

  16. Investigation of Gelatin Polypeptides of Jellyfish (Rhopilema esculentum for Their Antioxidant Activity in vitro

    Directory of Open Access Journals (Sweden)

    Yong-Liang Zhuang

    2010-01-01

    Full Text Available Jellyfish gelatin was hydrolyzed by different proteases to obtain antioxidative polypeptides. The gelatin hydrolysate obtained by progressive hydrolysis using trypsin and Properase E exhibited the highest hydrolysis degree and antioxidant activity. Three series of gelatin polypeptides (SCP1, SCP2 and SCP3 were obtained by ultrafiltrating the gelatin hydrolysate through molecular mass cut-off membranes of 10, 6 and 2 kDa, respectively. Amino acid composition analysis showed that SCP3 had the highest total hydrophobic amino acid content. The in vitro antioxidant tests demonstrated that SCP2 had the strongest hydroxyl radical and hydrogen peroxide scavenging activities and metal chelating ability, while SCP3 showed the highest reducing power, antioxidant activity in linoleic acid emulsion system and superoxide anion radical scavenging activity. The results support the feasibility of jellyfish gelatin as a natural antioxidant polypeptide provider, and enzymatic hydrolysis and ultrafiltration could be potent future processing technologies to utilize the abundant jellyfish resource.

  17. Gelatin increases the coarseness of whey protein gels and impairs water exudation from the mixed gel at low temperatures

    NARCIS (Netherlands)

    Martin, A.H.; Bakhuizen, E.; Ersch, C.; Urbonaite, V.; Jongh, H.H.J. de; Pouvreau, L.

    2016-01-01

    To understand the origin of water holding of mixed protein gels, a study was performed on water exudation from mixed whey protein (WP)-gelatin gels upon applied pressure. Mixed gels were prepared with varying WP and gelatin concentration and gelatin type to obtain gels with a wide range of gel

  18. Precision and agreement of corneal power measurements obtained using a new corneal topographer OphthaTOP.

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    Full Text Available To evaluate repeatability and reproducibility of anterior corneal power measurements obtained with a new corneal topographer OphthaTOP (Hummel AG, Germany and agreement with measurements by a rotating Scheimpflug camera (Pentacam HR, Oculus, Germany and an automated keratometer (IOLMaster, Carl Zeiss Meditec, Germany.The right eyes of 79 healthy subjects were prospectively measured three times with all three devices. Another examiner performed three additional scans with the OphthaTOP in the same session. Within one week, the first examiner repeated the measurements using the OphthaTOP. The flat simulated keratometry (Kf, steep K (Ks, mean K (Km, J0, and J45 were noted. Repeatability and reproducibility of measurements were assessed by within-subject standard deviation (Sw, repeatability (2.77 Sw, coefficient of variation (CoV, and intraclass correlation coefficient (ICC. Agreement between devices was assessed using 95% limits of agreement (LoA.Intraobserver repeatability and interobserver and intersession reproducibility of all measured parameters showed a 2.77 Sw of 0.29 diopter or less, a CoV of less than 0.24%, and an ICC of more than 0.906. Statistically significant differences (P<0.001 were found between the parameters analyzed by the three devices, except J0 and J45. The mean differences between OphthaTOP and the other two devices were small, and the 95% LoA was narrow for all results.The OphthaTOP showed excellent intraobserver repeatability and interobserver and intersession reproducibility of corneal power measurements. Good agreements with the other two devices in these parameters were found in healthy eyes.

  19. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

    Directory of Open Access Journals (Sweden)

    Jie Hou

    2016-01-01

    Full Text Available Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET and postoperative Q-value changes (ΔQ was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69±4.2, 5.19±3.8, and 6.23±3.9 μm at the center, paracenter, and mid-periphery, resp., P<0.01. A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r=0.438, 0.580, and 0.504, resp., P<0.01. Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia.

  20. Structural, Morphological, and Functional Correlates of Corneal Endothelial Toxicity Following Corneal Exposure to Sulfur Mustard Vapor

    Science.gov (United States)

    2013-10-01

    other provision of law , no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a...of the corneal endothe- lium during the acute SM injury and in resolved versus MGK corneas at 8 weeks. METHODS Ethics Statement and Disclaimers The...Endothelial Permeability Rabbits were euthanized 24 hours after exposure. Five minutes after euthanasia , 20 lL of a 0.1 mg/mL solution of AlexaFluor 488