-
-
-
Materials Science and Engineering C 02/2012; · 2.69 Impact Factor
-
Journal of Molecular Structure THEOCHEM 01/2011; 994:117-124. · 1.44 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this study, we report on physical and in vitro biological characterization of succinylated collagen (SC).
SC was prepared by succinylation of type I bovine tendon collagen. SC swells and dissolves in physiological
pH buffers (pH 7.4) Biocompatibility of SC to collagen for fibroblasts was comparable but L6 myoblasts
showed pronounced proliferation and differentiation with SC. Using the MALDI-TOF/MS
technique, SC was found with increased molecular mass by 16,359 Da per molecule which corresponds
to about 54 succinyl groups covalently linked to the collagen strand. Raman spectroscopy revealed the
retention of triple helical structure conformation in the presence of linked succinyl groups. New peaks
near 1737, 1675 and 1420 cm�1 and decreased intensities near 2440 and 488 cm�1 provides the most
convenient marker bands for succinylation of collagen. The intense band regions near 2856–2934,
2724, and 1445 cm�1 also confirms the existence of succinyl groups
Journal of Molecular Structure. 01/2011; 994:117-124.
-
Reactive and Functional Polymers 01/2011; 71:62–69. · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The antioxidant activity of the total aqueous extract (TAE) and total phenolic extract (TPE) of Momordica charantia fruits was assayed by radical-scavenging methods and cytoprotective effects on hydrogen peroxide (H(2)O(2))- and hypoxanthin-xanthin oxidase (HX-XO)-induced damage to rat cardiac fibroblasts (RCFs), NIH 3T3, and keratinocyte (A431). Cell viability was monitored by a 3-[4,5-dimethyltriazol-2-yl]-2,5-diphenyltretrazolium (MTT) assay. For fibroblasts, TPE at 200 and 300 microg/mL showed maximum and consistent cytoprotection against oxidants. The extract at 50 microg/mL also had significant and slightly protective effects on fibroblasts against H(2)O(2)- and HX-XO-induced damage, respectively. RCF was more tolerant toward the damage. For keratinocytes, a dose-dependent relationship of oxidant toxicity was only seen with H(2)O(2) but the protective action of the extract correlated with oxidant dosage. At 200 and 300 microg/mL TPE, cytoprotection was dose-dependent against oxidants. Extracts had no effect on HX-XO toxicity at 50 microg/mL. Pretreatment with both the extracts did not show any cytoprotection.
Journal of Agricultural and Food Chemistry 02/2010; 58(3):1518-22. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A series of novel choline based salts, some of which can be described as ionic liquids, are prepared and evaluated for their biocompatibility; when combined with collagenous biomaterials they exhibit good cell viability and adhesion properties as required for biomedical implant applications.
Chemical Communications 01/2010; 46(2):294-6. · 6.17 Impact Factor
-
Journal of Bioactive and Compatible Polymers. 01/2010; 25:419-436.
-
Advanced Engineering Materials 01/2010; 12:B380–B387. · 1.18 Impact Factor
-
Advanced Engineering Materials. 01/2010; 12:B380-B387.
-
[show abstract]
[hide abstract]
ABSTRACT: This is a pilot study of 10 eyes of 6 patients. This paper describes the preparation and clinical evaluation of succinylated collagen punctal plugs (SCPP) in the treatment of dry eye syndrome (DES).
SCPP were prepared from succinylated collagen with the exact dimensions of the punctum (length 1.5-2.5 mm, diameter 0.2-0.5 mm, water content between 50 and 55%). All the patients were clinically evaluated for best corrected visual acuity (BCVA), tear fluid levels (TFL), protein content, tear fluid osmolarity (TFO), fluorescence staining of the cornea and tear break-up time (TBUT) before and after punctal occlusion with SCPP.
TFL improved among all the patients after punctal occlusion with SCPP. BCVA showed improvement in case 4 (right eye/left eye), case 5 (left eye) and case 6 (right eye), who had developed dry eyes due to environmental conditions. Protein content increased on day 7 in all the patients and gradually decreased. TFO decreased on days 3 and 5 in all patients after punctal occlusion with SCPP, and showed the same levels on day 14. TFL, PC, TFO and TBUT showed significant improvement in all the patients after punctal occlusion with SCPP.
All patients experienced symptomatic relief after punctal occlusion with SCPP. There was no discomfort, foreign body sensation, plug extrusion, corneal aberration, infection, or formation of pyogenic granuloma with SCPP. SCPP stands as a promising alternative to other punctal plugs in the treatment of DES.
Ophthalmic Research 01/2010; 43(4):185-92. · 1.56 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Momordica charantia fruit is a widely used traditional medicinal herb as, anti-diabetic, anti-HIV, anti-ulcer, anti-inflammatory, anti-leukemic, anti-microbial, and anti-tumor.
The present study is undertaken to investigate the possible mode of action of fruit extracts derived from Momordica charantia (MC) and study its pharmacological effects for controlling diabetic mellitus. Effects of aqueous and chloroform extracts of Momordica charantia fruit on glucose uptake and up-regulation of glucose transporter (Glut-4), peroxisome proliferator activator receptor gamma (PPAR gamma) and phosphatidylinositol-3 kinase (PI3K), were investigated to show its efficacy as a hypoglycaemic agent.
Dose dependent glucose uptake assay was performed on L6 myotubes using 2-deoxy-D-[1-(3)H] glucose. Up-regulatory effects of the extracts on the mRNA expression level of Glut-4, PPAR gamma and PI3K have been studied.
The association of Momordica charantia with the aqueous and chloroform extracts of Momordica charantia fruit at 6 microg/ml has shown significant up-regulatory effect, respectively, by 3.6-, 2.8- and 3.8-fold on the battery of targets Glut-4, PPAR gamma and PI3K involved in glucose transport. The up-regulation of glucose uptake was comparable with insulin and rosiglitazone which was approximately 2-fold over the control. Moreover, the inhibitory effect of the cyclohexamide on Momordica charantia fruit extract mediated glucose uptake suggested the requirement of new protein synthesis for the enhanced glucose uptake.
This study demonstrated the significance of Glut-4, PPAR gamma and PI3K up-regulation by Momordica charantia in augmenting the glucose uptake and homeostasis.
Journal of ethnopharmacology 10/2009; 126(3):533-7. · 2.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of the study was to evaluate the efficacy of succinylated collagen bandage lenses (SCBL) in the healing of various corneal conditions.
Clinical evaluation of SCBL was carried out in patients with corneal ulcer (CU), recurrent corneal erosions (RCE), dry eyes (DE) and corneal lesion (CL). In each patient, corneal healing was studied by subjective clinical assessment such as pain, redness, watering, discomfort, irritation, foreign body sensation, biochemical analysis of tear fluid (TF) for protein content, expression of matrix metalloproteinases (MMPs) by gelatin zymography (GZ) and Western blotting (WB). In both GZ and WB bands were quantified and analyzed by gel documentation analyzer.
Subjective clinical assessment of CU, RCE, DE and CL patients after treatment with SCBL showed significant reduction in the symptoms, patients felt comfortable with SCBL with no change in visual acuity, indicating complete transparency of SCBL. Protein content was very high on day 1 among all the patients, and it reduced gradually after treatment with SCBL signifying corneal healing. GZ of TF showed the expression of both MMP-2 and MMP-9 on day 3. There was significant reduction in MMP-2 and MMP-9 expression on day 7 in all cases, it decreased considerably on day 14 and was almost negligible on day 21 reflecting corneal healing with SCBL.
Our study indicated that SCBL significantly reduces symptoms of irritation and discomfort in the cornea. It maintains visual acuity, controls inflammation and watering in the eye reflecting corneal healing in all cases studied by us. SCBL represents a promising alternative to other bandage lenses in corneal healing.
Ophthalmic Research 06/2009; 42(2):64-72. · 1.56 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To study whether succinylated collagen bandage lenses (SCBL) prepared from modified bovine collagen (succinylated collagen) can replace other bandage lenses presently employed to treat various corneal conditions like filamentary keratitis, dry eyes, recurrent corneal erosions, foreign body removal and epithelial trauma.
This observational case study included 32 patients (22 female and 10 male): 8 patients for filamentary keratitis (25%), 10 patients for dry eyes (31%), 4 patients for recurrent corneal erosions (13%), 7 patients for foreign body removal (22%) and 3 patients for epithelial trauma (9%). Their eyes were evaluated for biocompatibility, in vivo transparency, patient comfort, corneal fit, best corrected visual acuity (BCVA), tear fluid level and dissolution rate of SCBL. This was carried out over a 24-hour period of time.
SCBL exhibited good transparency and remained transparent throughout the period of study (between 0 and 24 h) in the eyes of patients. SCBL did not cause any irritation, discomfort and foreign body sensation in the eye and eyes remained comfortable throughout the experiment. BCVA in the control group of patients was 1.00 (20/20). Mean (+/-SD) BCVA before inserting SCBL (in decimal equivalent) was 0.31 (20/60) +/- 0.18 (range 0.1- 0.66). BCVA (+/-SD) changed to 0.25 (20/80) +/- 0.18 4 h after the application of SCBL and 0.27 (20/70) +/- 0.18 24 h after the application of SCBL, with a safety index of 1.20. The mean (+/-SD) tear fluid level before application of SCBL was 11.9 +/- 5.39 h (range 3-24 mm) and changed to 13.9 +/- 5.68 h (range 5-28 mm) after 4 h of application of SCBL and 15.9 +/- 5.72 h (range 7-30 mm) after 24 h with a safety index of 13 mm. The mean (+/-SD) dissolution rate of SCBL in the control group of patients was 17.8 +/- 8.65 h (range 10-24 h) and the mean (+/-SD) dissolution rate in the experimental group was 22.2 +/- 9.29 h (range 10-24 h). We report the use of SCBL in various corneal conditions.
The present study showed that SCBL has complete corneal fit and good comfort in human eyes. Transparency was maintained for a longer period along with fair visual acuity and improvement in tear fluid levels. The disadvantages of other bandage lenses presently used to treat various corneal conditions could be overcome by the use of SCBL lenses.
Ophthalmic Research 05/2008; 40(5):257-66. · 1.56 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Native proteolytic microorganisms were isolated from the hornmeal, which is a product obtained by treatment of horns and hoofs
with steam under high pressure. Keratinolytic activities of these organisms were screened in mineral salt medium with 1% hornmeal.
Bacillus subtilis MTCC (9102), a keratinase-producing organism causing extensive degradation of hornmeal has been identified. Keratinase was
purified (45-fold) by ion exchange, and gel filtration chromatography. Among the keratinases produced by the various organisms,
keratinase from the Bacillus subtilis strain reported by us was found to have a molecular weight range between 64 and 69kDa and high activity in the pH range
between 5 and 7, with maximum activity at pH 6.0 and at an optimum temperature of 40°C. It remained stable up to 70°C. The
keratinase activity was completely inhibited by ethylenediamine tetraacetic acid (EDTA), and 1 10-phenanthroline, and remained
unaffected by phenylmethanesulfonyl fluoride (PMSF, relative activity: 93%), whereas iodoacetamide inhibited considerably.
Zinc, magnesium, calcium, manganese, and nickel were found to enhance the enzyme activity, whereas mercury and copper inhibited
its activity completely. The keratinolytic metalloprotease from native Bacillus subtilis differed from the other serine proteases. It may have potential applications in the bioconversion of keratinous wastes and
eco-friendly dehairing in the leather industry.
World Journal of Microbiology and Biotechnology 01/2008; 24(11):2741-2745. · 1.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this study the efficacy of chemically modified type I collagen film as barrier membrane in guided tissue regeneration (GTR) procedure was assessed in patients with gingival recession defect. 20 Patients with Millers Class I or Class II furcation defects were selected and divided into test and control groups in which test group alone was treated with collagen membrane to cover the exposed root surface. Pre-operative (baseline) and post-operative (24 weeks) clinical recordings like plaque Index (PI), gingival index (GI) recession depth (RD), probing depth (PD), Percentage of recession coverage (RC) and clinical attachment level (CAL) were assessed in both groups. Test group showed significant root coverage (63.79%) than the control group (59.09%). The difference in mean probing depth (PD) was significantly reduced by 0.4 mm in test group, but in control group the mean PD was increased by 0.6 mm (p<0.0001). Statistically significant Clinical attachment (CA) gain of 55.9% (4.1 mm) was found in treated group than the control group, which has shown 36.36 % (2 mm) of CA gain (p=0.001). No significant changes were found in plaque index (PI) and gingival index (GI) between the groups. These results demonstrated that the clinical improvement of gingival recession defects in GTR procedure can be achieved by using modified collagen barrier membrane for the effective reconstruction of the mucogingival unit.
Trends Biomater. Artif. Organs. 01/2008; 21:85-93.
-
[show abstract]
[hide abstract]
ABSTRACT: Keratin, a fibrous protein forming main structural constituent of feather, hair, wool, horn, hoof etc., is abundantly available as a by-product from poultry, slaughterhouse, tanning and fur processing industry. Keratins though find applications in food, pharmaceutical, cosmetic and fertilizer industry, considerable amount of these products is wasted repeatedly. Keratins are difficult to degradation and their disposal leads to environmental problems. Research is being done globally to utilize these wastes. Keratin hydrolysates find potential application in leather tanning industry. Introduction India has a large livestock population, which produce annually: goatskins, 82; sheep skins, 30; cattle hides, 23; and buffalo hides, 28 million 1 . World production of bovine and ovine skins during 2000 was 1,192 million pieces 2 . Feathers constitute up to 8-10% of total chicken weight and it is estimated that several million tons of feathers are produced annually. Bovine and ovine hair is obtained as a by-product from the tanneries during hair-saving unhairing process and it is estimated that about 5% of dry hair is recovered based on the raw hide weight 3,4 . But still most of the tanneries are following hair-burning process, which destroy the hair completely and contribute high amount of COD, BOD, TDS etc., to the effluent 5-8 . Microbial proteases offer potential solution to remove the hair completely from the raw skins 9-12 . An enormous quantity of keratins in the form of hairs, feathers, horns and hoofs are wasted each year 13 . Keratins are broadly classified as hard (5% sulfur) and soft (1% sulfur) keratins. Keratin is mechanically robust and chemically unreactive due to tight packing of protein chain in the form of α-helix or β-sheet into a super coiled polypeptide chain crosslinked with disulfide bonds. In horns, hoofs and hair, keratin is in the form of α-keratin, whereas in feathers it is in the form of β-keratin 14-17 .
Journal of Scientific & Industrial Research. 10/2007; 66:710-715.
-
[show abstract]
[hide abstract]
ABSTRACT: The present paper describes an accurate and cost-effective method requiring simple equipment to measure the oxygen permeability and transmissibility of contact lenses.
The method involves accurate measurement of oxygen across the material by allowing the gas (oxygen) to pass through the lens material in a specially fabricated lens mould. The expelled gas is collected by dissolution in ethanol and the oxygen is measured by titration of the solvent.
This method is suitable for the measurement of oxygen permeability and transmissibility of contact lenses of varying thickness and different radii of curvature. It can measure Dk and Dk/t of collagen bandage lenses in both wet and dry conditions.
The oxygen permeability and transmissibility values obtained by this method were compared with the oxygen permeability standard values of commercially available contact lenses and the results are summarised.
Clinical and Experimental Optometry 12/2006; 89(6):374-80. · 1.05 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Enzyme-treated acid-solubilized bovine collagen (ESBC Type I) prepared in laboratory-grade glass and polypropylene ware under identical conditions have shown different conformational and mechanical properties. Circular dichroism (CD) studies on ESBC have shown higher triple-helical contents in polypropylene laboratory-grade ware compared to laboratory ware of glass. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetric (DSC) studies have supported the conformational changes performed on both preparations. Both preparations, in membrane form, were evaluated for their mechanical properties—viz., shrinkage temperature (St), dissolution temperature (Dt), and tensile strength (Ts). The collagen membrane of ESBC prepared in polypropylene showed significantly higher values compared to glass ones. No difference was seen in shrinkage temperature data of the two membranes. Reduced viscosity of ESBC was also measured for both preparations, and it had a significantly higher value in polypropylene ware compared to ESBC prepared in glassware. We postulate that the presence of silicate ions (SiO3−2) in glassware has a role in all these changes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2186–2192, 2003
Journal of Applied Polymer Science 01/2003; 87(13):2186 - 2192. · 1.29 Impact Factor
