40 results on '"Rekha MR"'
Search Results
2. Synthesis and evaluation of an alginate-methacrylate xerogel for insulin delivery towards wound healing applications
- Author
-
Rajalekshmy, GP, primary and Rekha, MR, additional
- Published
- 2021
- Full Text
- View/download PDF
3. Cationised dextran and pullulan modified with diethyl aminoethyl methacrylate for gene delivery in cancer cells
- Author
-
Harikrishnan V S, M. Caroline Diana Sherly, and Rekha Mr
- Subjects
Biodistribution ,Polymers and Plastics ,Cell Survival ,Surface Properties ,02 engineering and technology ,Gene delivery ,010402 general chemistry ,Polysaccharide ,01 natural sciences ,HeLa ,chemistry.chemical_compound ,Cations ,Cell Line, Tumor ,Materials Chemistry ,Ethylamines ,Humans ,Polyethyleneimine ,Particle Size ,Glucans ,chemistry.chemical_classification ,biology ,Organic Chemistry ,Gene Transfer Techniques ,Pullulan ,Dextrans ,Transfection ,Genetic Therapy ,021001 nanoscience & nanotechnology ,biology.organism_classification ,0104 chemical sciences ,Dextran ,chemistry ,Biochemistry ,Cancer cell ,Methacrylates ,0210 nano-technology ,HeLa Cells - Abstract
This work describes the synthesis and characterisation of cationised dextran and pullulan modified with diethyl aminoethyl methacrylate (DEAEM) for gene delivery in cancer cells. To dextran and pullulan, PEI was conjugated to impart cationicity. These cationised polysaccharides were then modified with DEAEM monomer via Michael addition reaction and synthesised four different derivatives viz DPD I, DPD II, PPD I and PPD II. These vectors form nanocomplexes with DNA exhibiting positive zeta potential. These nanoplexes are cytocompatible in C6, HeLa and L929 cells. Transfection efficiency of these vectors was evaluated using p53 plasmid which demonstrated good transfection in cancer cells (C6 and HeLa) alone. Biodistribution studies of DPD II and PPD II in BALB/c mice shows its tendency to accumulate in liver tissue and not in any vital organs like brain, lungs and heart. In addition, these derivatives also exhibit good renal clearance.
- Published
- 2019
4. Barriers to gene delivery: systemic and intracellular
- Author
-
Ambattu, Lizebona August, primary, Rekha, MR, additional, and Sharma, Chandra P, additional
- Published
- 2015
- Full Text
- View/download PDF
5. Effect of pulsed electric field treated on quality of curd.
- Author
-
Preeti B, Ravindra MR, Shivaram M, Gajanan DP, and Singh AM
- Subjects
- Animals, Humans, Food Microbiology, Hydrogen-Ion Concentration, Hot Temperature, Viscosity, Food Quality, Taste, Food Preservation methods, Food Handling methods, Electricity, Milk microbiology, Milk chemistry
- Abstract
Pulsed electric field (PEF) is a potential pre-treatment technique to improve the quality of milk by reducing its microbial load. The present study aims at addressing this issue with respect to a popular fermented dairy product, that is, curd. Milk was treated with high voltage and frequency (55 kV and 90 Hz) square waves of pulse width 900 µs for 100 s. Curd samples were prepared with conventional heat treatment (CHT), PEF-treated milk subjected to CHT (PT-CHT), and PEF-treated milk (PT). PT samples resulted in curd with higher acidity (0.17 ± 0.005% LA) and microbial load (6.65 ± 0.27 log CFU/g), while the PT-CHT samples resulted in curd with better whey holding capacity. The firmness recorded for CHT, PT-CHT, and PT was 1.15 ± 0.05, 1.32 ± 0.04, and 0.91 ± 0.03 N, respectively. PT-CHT showed a higher viscosity index, that is, 0.207 ± 0.005 g. Sensorial properties showed the acidic nature of PT-curd with greater syneresis and softer texture resulted in its poorer sensory scores for texture. Shelf-life analysis showed no significant difference between curd prepared using the CH and PT-CHT up to 12 days. The study demonstrated the potential of employing PEF with CHT for improving the texture and shelf life of curd without impacting its quality., Competing Interests: DECLARATION OF CONFLICTING INTERESTSThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2024
- Full Text
- View/download PDF
6. Design, synthesis, and biological evaluation of pyrazole-ciprofloxacin hybrids as antibacterial and antibiofilm agents against Staphylococcus aureus .
- Author
-
Ommi O, Dhopat PS, Sau S, Estharla MR, Nanduri S, Kalia NP, and Yaddanapudi VM
- Abstract
In our continued efforts to tackle antibiotic resistance, a new series of pyrazole-ciprofloxacin hybrids were designed, synthesized, and evaluated for their antibacterial activity against Staphylococcus aureus ( S. aureus ), Pseudomonas aeruginosa ( P. aeruginosa ), and Mycobacterium tuberculosis ( Mtb ). Most of the compounds exhibited good to excellent activities against S. aureus , and six compounds (7a, 7b, 7d, 7g, 7k, and 7p) exhibited higher or comparable activity (MIC = 0.125-0.5 μg mL
-1 ) to ciprofloxacin (0.125 μg mL-1 ). Further, these selected compounds were non-toxic (CC50 ≥ 1000 μg mL-1 ) when evaluated for cell viability test against the Hep-G2 cell line. Three compounds (7a, 7d, and 7g) demonstrated excellent activity against ciprofloxacin-resistant S. aureus with MIC values ranging from 0.125-0.5 μg mL-1 and good antibiofilm activity. Among them, 7g displayed remarkable antibiofilm activity with an MBIC50 value of 0.02 μg mL-1 , which is 50 times lower than ciprofloxacin (MBIC50 = 1.06 μg mL-1 ). A time-kill kinetics study indicated that 7g showed both concentration and time-dependent bactericidal properties. In addition, 7g effectively inhibited DNA-gyrase supercoiling activity at 1 μg mL-1 (8× MIC). Two compounds 7b and 7d exhibited the highest activity against Mtb with a MIC of 0.5 μg mL-1 , while 7c showed the highest activity against P. aeruginosa with a MIC value of 2 μg mL-1 . Molecular docking studies revealed that 7g formed stable interactions at the DNA active site., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2024
- Full Text
- View/download PDF
7. A combination of calcium hydroxide and sodium hydrosulphate controls pathogens causing environmental mastitis in recycled manure solids.
- Author
-
Praveen S, Kataktalware MA, Meena P, Lavanya M, Patoliya P, Jeyakumar S, Ravindra MR, Chauhan M, Ramesha KP, Devi GL, Kastelic JP, and Dhali A
- Abstract
Recycled manure solids (RMS) are dried cow dung processed using a manure dewatering machine and subsequently sun-dried to ~ 20% moisture. Benefits of RMS include abundant availability, low cost, and eco-friendliness, but its use as bedding material for cows is hindered by a moisture content that promotes microbial growth. This in vitro study evaluated impacts of calcium hydroxide (CH; 5 and 7.5%) and sodium hydrosulphate (SHS; 6 and 8%), independently and in combinations, at various depths of RMS, on physicochemical and microbial properties. The CH-treated groups had increased pH and reduced moisture on Day 0. Incorporating 7.5% CH + 6% SHS at 15-20 cm, and 7.5% CH + 8% SHS at all depths, effectively suppressed Escherichia coli and Klebsiella spp. Furthermore, a combination of 7.5% CH + 8% SHS at 20 cm inhibited coliform growth, whereas 7.5% CH with 6% SHS inhibited Streptococcus spp. In conclusion, a combination of 7.5% CH with either 6 or 8% SHS at a depth of 15 cm in RMS was particularly effective in controlling environmental mastitis-causing pathogens, specifically E. coli and Klebsiella spp., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
8. Enhancing hoof health and locomotion in crossbred dairy cows: impact of recycled manure solids bedding on lameness incidence and gait kinematics.
- Author
-
Praveen S, Kataktalware MA, Lavanya M, Abhijeet S, Chinnusamy D, Jeyakumar S, Ravindra MR, Devi GL, and Ramesha KP
- Subjects
- Animals, Cattle, Female, Biomechanical Phenomena, Hoof and Claw, Incidence, Animal Welfare, Recycling, Floors and Floorcoverings, Lameness, Animal epidemiology, Lameness, Animal prevention & control, Gait, Cattle Diseases prevention & control, Cattle Diseases epidemiology, Housing, Animal, Locomotion, Dairying methods, Manure analysis
- Abstract
Recycled manure solids has emerged as a promising alternative for animal bedding, owing to its economic feasibility, ready availability on farms, and soft, non-abrasive nature. This research aimed to assess the impact of recycled manure solids (RMS) bedding, combined with a conditioner containing 7.5% lime and 6% sodium hydrosulphate, on dairy cow welfare and gait kinematics over three months. Hock and knee injury scores, lameness incidence, and gait kinematic parameters were evaluated for animals housed on cement flooring (Control), RMS bedding (Treatment I), and conditioner-added RMS bedding (Treatment II) on days 0, 45, and 90 of the experiment with six crossbred cows in each group. The results revealed a significant reduction (p < 0.05) in lameness scores (5-point scale) for animals in both the RMS and conditioner-added RMS groups, with scores of 1.09 ± 0.05 and 1.04 ± 0.03, respectively, compared to those on cement floors. Moreover, a noteworthy decrease (p < 0.05) in knee and hock injury scores (4-point scale) was observed in the RMS groups, indicating a potentially positive impact on joint health. Gait kinematic analysis demonstrated that animals in the RMS (1.03 ± 0.04 m/s) and conditioner-added RMS (1.02 ± 0.06 m/s) groups exhibited higher walking speeds and increased step angles (158.59 ± 4.82° and 149.58 ± 3.85°) compared to their cement-floor counterparts. No significant changes (p > 0.05) were observed in stride length, step asymmetry, step length, and step width. The study concluded that the conditioner incorporated recycled manure solids resulting in a substantial decrease in lameness incidence and a reduction in hock and knee injuries among dairy cows. Additionally, the improved gait kinematics observed in non-lame animals suggest that this bedding combination positively influences overall animal well-being. These findings underscore the potential of sustainable bedding practices to enhance both physical health and locomotor behaviour in dairy cattle., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)
- Published
- 2024
- Full Text
- View/download PDF
9. The effect of the different waves of COVID-19 pandemic on the outcome of diabetic foot ulcers.
- Author
-
Goyal G, Majumdar S, Biswas Bose U, Shrivastava MR, Mukherjee JJ, Banka SP, Kapoor S, and Jude E
- Abstract
Aims: COVID-19 pandemic has massively impacted human health. We studied the effect of COVID-19 on outcome of Diabetic foot ulcers (DFUs)., Objectives and Methods: We recruited 483 people with DFUs from June 2020 to April 2022 (pandemic) together with a matched group of 226 people with DFU from March 2019 to March 2020 (pre-pandemic). Primary endpoint was outcome of ulcers-healed or amputation (major/minor). It was sub-analysed into 3 waves of COVID-19. Secondary endpoint was healing of individual types of DFUs. Basic anthropometric data included site and type of ulcer (ischemic or neuropathic), duration, presence or absence of infection and Wagner's grading of DFUs was collected for all patients. Diagnosis of peripheral neuropathy was done by monofilament testing and peripheral arterial disease by handheld Doppler and ankle brachial index (ABI). Standardized treatment protocol was provided. All patients were monitored for 6 months., Results: In the pandemic group 323 (66.9%) patients in whom ulcers healed, 70 (14.5%) underwent minor amputation, 11 (2.2%) major amputation, 29 (6%) were lost to follow up, 22 (4.6%) were not healed. Rate of healing of DFU was higher (66.9% vs 53.5%) and rate of amputation was lower (16.7% vs 23.4%) in the pandemic group than in the pre-pandemic group (P = 0.001 and 0.037 respectively). Rate of healing in first, second and third wave was 65.4%, 75.2%, 58.3% respectively (P = 0.001). Neuropathic ulcers though less prevalent (49.8% vs 57.8%) in the first two waves than in the third wave, healing was better (79.3% vs 75.6%) in the first two waves than in the third wave (P = 0.085 and 0.488 respectively). Similarly, amputation rates in ischemic and neuro-ischemic ulcers were greater in the third wave than first two waves (46.7% vs 15.7%, P = 0.049)., Conclusion: During the COVID-19 pandemic, healing of neuropathic ulcers was better, especially in the first and second waves and travel restriction may have accounted for this. However, worsening of ischemic and neuro-ischemic ulcers was observed with more amputation in these two groups. Conversely, in the third wave withdrawal of lockdown led to worsening of DFUs resulting in less healing and more amputation., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2024
- Full Text
- View/download PDF
10. Ascorbic acid-loaded gellan-g-poly(ethylene glycol) methacrylate matrix as a wound-healing material.
- Author
-
Ravi D, Rajalekshmy GP, Rekha MR, and Joseph R
- Subjects
- Humans, Methacrylates chemistry, Keratinocytes drug effects, Keratinocytes metabolism, Fibroblasts drug effects, Animals, Ascorbic Acid pharmacology, Ascorbic Acid chemistry, Wound Healing drug effects, Polysaccharides, Bacterial chemistry, Polysaccharides, Bacterial pharmacology, Polyethylene Glycols chemistry, Hydrogels chemistry, Hydrogels pharmacology
- Abstract
Ascorbic acid (AA) is one of the important biomolecules involved in all phases of wound healing. The aim of this study was to develop a new hydrogel system that offers topical delivery of ascorbic acid to wounds during wound care management. In this work, we grafted poly (ethylene glycol) methacrylate onto a renewable biopolymer gellan, and the graft copolymer (GPMA) formed was crosslinked covalently and ionically, and used as a matrix for delivering AA to the wounds. By the processes of grafting and crosslinking, the mechanical properties of the gellan increased several fold compared to mechanically weak native gellan. In vitro cytotoxicity evaluation showed that GPMA was non-cytotoxic to fibroblast cells. GPMA hydrogel matrix allowed the sustained release of AA. When AA was incorporated in GPMA, a significant improvement in wound closure was observed in scratch wound assay performed with keratinocytes. Since AA acts as a cofactor in collagen synthesis, the controlled delivery of AA to the wound microenvironment favors the up-regulation of colα1 gene expression. This study revealed that ascorbic acid, at a concentration of 150 μM, has a favorable impact on wound healing when tested in vitro. Overall results indicate that the GPMA matrix could be a promising material for wound healing applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
11. Impact of pulsed electric field treated milk on quality of paneer and khoa .
- Author
-
Preeti B, Ravindra MR, Surendra Nath B, and Gajanan Panditrao D
- Subjects
- Animals, Colony Count, Microbial, Hot Temperature, Milk microbiology, Food Preservation methods
- Abstract
The present work was undertaken to investigate the feasibility of pre-treatment of raw milk with Pulse Electric Field (PEF) treatment before its entry into the processing chain. A custom-designed and fabricated PEF applicator was used for the non-thermal treatment protocol. Raw milk was treated under three treatment protocols, viz., conventionally heat treatment (CHT), PEF treated milk subjected to conventional heat treatment (PT-CHT) and PEF treatment (PT). For the PT protocol, milk was subjected to high voltage (55 kV) square wave of pulse width 900 µs, for 100 s at a frequency of 90 Hz. The treated milk was then converted to two popular products, namely and paneer and khoa , which were evaluated for its physico-chemical, microbiological, sensory quality and shelf stability. Since khoa is a heat desiccated product, it was evaluated only against PT-CHT and CHT treatments. It was observed that PT treatment resulted in paneer with softer body with higher whiteness index, compared to other experimental samples. The PT treatment did not affect the product acceptability and the product had a shelf stability of 12 days under refrigeration, as against 16 days for CHT and PT-CHT treatment. The treatment protocols for milk did not significantly affect the quality and shelf life of khoa . Thus, there is wide future scope to used pulsed electric fields treatment synergistically with conventional heat treatment for inactivation of microorganisms, with better retention of nutritional and physical properties of product which has potential to save considerable amount of energy and time during processing of product.
- Published
- 2023
- Full Text
- View/download PDF
12. Proline conjugated chitosan as wound healing material: In vitro studies on the influence of the scaffold on collagen production and wound healing.
- Author
-
Linju MC and Rekha MR
- Subjects
- Proline pharmacology, Collagen chemistry, Wound Healing, Tissue Scaffolds chemistry, Chitosan pharmacology, Chitosan chemistry
- Abstract
The present study reports the development of L-proline conjugated chitosan scaffold for wound healing application. Proline plays a beneficial role in collagen synthesis, and as a biochemical, it has the potential to modulate wound healing. In this regard, amino acid L-proline was conjugated onto chitosan, and the scaffolds were synthesised. FTIR and NMR analysis confirmed amino acid conjugation. The prepared scaffold was characterized by studies such as swelling, dissolution, tensile strength, porosity, water-vapor transmission rate and in-vitro healing properties. Cell viability assay showed that the scaffold has no cytotoxicity against the L929 and HaCaT cells. The in-vitro wound healing potential of the scaffold by scratch wound assay on the L929 cell line showed 53.35 ± 2.3 %, 72.96 ± 2.2 %, and 50.89 ± 0.3 % wound closure for CS-P 200, CS-P 400 and CS-P 600, respectively when compared to native CS scaffold (38.86 ± 1.6 %). A similar observation was found with HaCaT cells too. The studies showed that the modified scaffold promotes collagen deposition from fibroblast cells. These findings suggest that scaffold cues remodel the wound microenvironment for a better wound-healing state, and the L-proline conjugated scaffold may have considerable potential as a wound dressing to improve wound healing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
13. Sorption and thermodynamic properties of dry crystallized Palada payasam mix prepared using manual and mechanical stirring.
- Author
-
Jose N, Ravindra MR, Deshmukh GP, and Rao KJ
- Abstract
An attempt was made to develop mathematical models to describe the sorption behaviour and determine the thermodynamic properties of sorption of dry-crystallized Palada payasam mix at different water activities (between 0.113 and 0.973) and temperature ranging from 25 to 35 °C. Samples were prepared using both manual and mechanical mixing during the crystallization process and the equilibrium moisture content (EMC) was recorded using the isopiestic technique to compare the sorption behaviour of both samples. The sorption isotherms were found to follow a J-shape-type III plot, with the sorption capacity decreasing with temperature. The isotherms also exhibited a typical temperature inversion of EMC at water activity > 0.70. The sorption data obtained was fitted to 12 mathematical models for sorption and the Guggenheim, Anderson and de Boer (GAB), Peleg and Iglesias and Chirife models were found to describe the data over the entire range of water activity with a good fit. The isosteric heat of sorption and spreading pressure were determined as a function of moisture content. Isosteric heat of the samples was computed and found to decrease from 51.75 to 47.16 kJ/mol for control (manually stirred) and 49.38 to 47.58 kJ/mol for experimental sample (mechanically stirred) for a range of moisture content up to 29% (d.b). The spreading pressures increased with increasing water activity but decreased with increasing temperature. No significant difference was observed between the sorption properties of the dry crystallized samples prepared using manually and mechanically stirring., Competing Interests: Conflicts of interestWith the submission, we hereby confirm that no conflict of interest in submission of paper to journal., (© Association of Food Scientists & Technologists (India) 2021.)
- Published
- 2022
- Full Text
- View/download PDF
14. Optimization of recombination of milk at different fat levels in a small volume universal disperser unit.
- Author
-
Datir RP, Ravindra MR, Manjunatha M, and Sharma M
- Abstract
Recombined milk (RM) can be prepared by blending of butteroil, skim milk powder and water and used for variety of purposes in dairy industry. The present work was undertaken to investigate the feasibility of a custom designed and fabricated universal disperser unit for the preparation of recombined milk. Water, SMP and butteroil were used to manufacture the recombined milk. Three levels of fat viz 1.5%, 3.0% and 4.5% were evaluated to study the effect of fat content on the recombination efficiency of the universal disperser using a high shear saw tooth impeller to impart the required shear and disperse the fat in water-SMP matrix to form a stable emulsion. Two independent parameters i.e. temperature at three different levels (20, 35 and 50 °C) and impeller speed (10,000, 15,000 and 20,000 rpm) were selected for the study. All operations were carried out in heating cum process vessel having working capacity of 3 L. The efficiency of the operation was judged based on the dependent parameters namely, mixing time, mixing index, creaming index, power consumption and overall acceptability. Experiments were designed as per RSM in Design Expert V.10.0 software and results obtained were optimized and predicted solutions were compared with observed data. From the study, the optimal combinations for preparation of recombined milk were obtained as 1.5% Fat RM (17,820 rpm, 48 °C), 3.0% Fat RM (15,701 rpm, 48 °C) and 4.5% Fat RM (15,459 rpm, 48 °C)., (© Association of Food Scientists & Technologists (India) 2020.)
- Published
- 2021
- Full Text
- View/download PDF
15. Evaluation of vacuum impregnation as a novel approach for soaking of fried Gulabjamun balls.
- Author
-
Sharanabasava, Ravindra MR, Praveen Kumar YS, Manjunatha M, Mahesh Kumar G, and Nath BS
- Abstract
Vacuum impregnation of sugar syrup into sub-baric fried Gulabjamun was evaluated as a technological approach to prepare a product of most acceptable quality. Sugar syrup concentrations (40, 50 and 60 °Brix) in combination with process time (2, 4 and 6 min) were analyzed for their effect on product quality in terms of its overall acceptability, expansion ratio, hardness, juiciness and sugar content. The effect of the process conditions on the five listed responses during the vacuum impregnation process was evaluated using response surface methodology and modelled using a second order polynomial equation. The optimum combination was obtained as soaking in a syrup of 55 °Brix for 5 min and was experimentally validated for its real time adequacy. The experimental values of the quality parameters thus obtained were found to be in close agreement with the predicted values.
- Published
- 2019
- Full Text
- View/download PDF
16. Control of matting temperature during pressing of Paneer and its effect on Paneer quality.
- Author
-
Arvind SA, Ravindra MR, Manjunatha M, Emerald FME, Deshmukh GP, and Datir R
- Abstract
An attempt was made to design, fabricate and evaluate a heat exchanger for controlling the matting temperature of Paneer during pressing. Based on preliminary investigations, the range of process parameters to be evaluated during the pressing of Paneer was selected as: pressure (2, 3, and 4 kg/cm
2 ), matting temperature (63, 66 and 69 °C) for pressing time of 8, 10 and 12 min. Experiments were designed in a central composite design for 20 runs and the Paneer was evaluated for its moisture content, hardness, springiness, chewiness, cohesiveness, bulk density, porosity and sensory attributes. It was observed that with increasing pressure and matting temperature, the hardness of the product increased; this corresponded with reduced moisture content and porosity of the product. The springiness of the samples correlated linearly with increasing matting temperature and pressing time. Increasing the pressure during pressing resulted in poorer sensory scores. The process conditions for pressing of Paneer under controlled matting conditions were optimised using Response Surface Methodology for moisture content, overall acceptability, hardness and springiness of the pressed product. It was observed that the moisture content of Paneer pressed under controlled matting temperature was marginally lower than the control Paneer , the overall acceptability for the experimental samples was higher with superior body and texture scores.- Published
- 2019
- Full Text
- View/download PDF
17. Histidine and arginine conjugated starch-PEI and its corresponding gold nanoparticles for gene delivery.
- Author
-
Dhanya GR, Caroline DS, Rekha MR, and Sreenivasan K
- Subjects
- Arginine chemistry, DNA chemistry, Gold chemistry, Green Fluorescent Proteins genetics, HeLa Cells, Histidine chemistry, Humans, Polymers chemistry, Starch genetics, Transfection, Cell Survival genetics, Gene Transfer Techniques, Metal Nanoparticles chemistry, Starch chemistry
- Abstract
The high surface energy of gold nanoparticles (GNPs) along with its unique physical and chemical properties delivers it as an effective nonviral gene delivery platform for anticancer treatments. GNPs were synthesized by using starch-PEI in which PEI act as reducing agent and starch as a stabilizer. Cytocompatibility studies carried out in C6 cells revealed that gold modification significantly improved the percentage cell viability even at higher polymer concentration. Irrespective of excellent cellular internalization, the transfection efficiency studied with p53 plasmid was found to be compromised with gold modification. For better transfection efficiency, we further modified starch-PEI with amino acids (l-Arginine, l-Histidine) and synthesized the corresponding GNPs. Though starch-PEI gold nanoparticles exhibited low transfection, its amino acid modified counterparts were found to have good transfection efficiency along with low cytotoxicity. It was found that the GNPs containing l-Arginine showed improved transfection efficiency. Hence, it can be inferred that selective amino acid modification is beneficial for improving the transfection efficiency., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
18. Efficacy of vinyl imidazole grafted cationized pullulan and dextran as gene delivery vectors: A comparative study.
- Author
-
Caroline Diana SM and Rekha MR
- Subjects
- Biological Transport, Drug Carriers metabolism, Drug Carriers pharmacology, HeLa Cells, Humans, Materials Testing, Particle Size, Plasmids genetics, Polyethyleneimine chemistry, Dextrans chemistry, Drug Carriers chemistry, Glucans chemistry, Imidazoles chemistry, Transfection
- Abstract
The present study deals with efficacy evaluation of two cationised polysaccharides - Pullulan PEI and Dextran PEI as gene delivery vector after grafting with vinyl imidazole. Chemical modifications of these polysaccharides were confirmed by FTIR and NMR. Nanoplex formed from dextran PEI imidazole (DPI) were of smaller size and possess greater positive charge as compared to that of pullulan PEI imidazole (PPI). MTT assay carried out in C6 and HeLa cell lines revealed that both PPI and DPI are cytocompatible and the percentage cell viability is higher for former. Though DPI and PPI derivatives showed similar cellular uptake, the cell morphology was maintained with later and this may due to the high molecular flexibility of pullulan that masks the cytotoxicity of PEI. Similarly transfection studies carried out with p53 plasmid also revealed that PPI derivatives promote more apoptosis in both C6 and HeLa cell lines as compared to that of DPI derivatives. Based on cytocompatibility and transfection efficiency, PPI was found to be a better gene delivery vector that can be further explored for in vivo applications., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
19. Alginate stabilized gold nanoparticle as multidrug carrier: Evaluation of cellular interactions and hemolytic potential.
- Author
-
Dey S, Sherly MC, Rekha MR, and Sreenivasan K
- Subjects
- Animals, Biological Transport, Curcumin chemistry, Drug Carriers metabolism, Drug Carriers pharmacokinetics, Drug Carriers toxicity, Drug Stability, Glucuronic Acid chemistry, Gold metabolism, Gold pharmacokinetics, Gold toxicity, Hexuronic Acids chemistry, Humans, MCF-7 Cells, Methotrexate chemistry, Rats, Alginates chemistry, Drug Carriers chemistry, Gold chemistry, Hemolysis drug effects, Metal Nanoparticles chemistry
- Abstract
This work delineates the synthesis of curcumin (Ccm) and methotrexate (MTX) conjugated biopolymer stabilized AuNPs (MP@Alg-Ccm AuNPs). The dual drug conjugated nano-vector was characterized by FTIR, (1)H NMR and UV-vis spectroscopic techniques. Hydrodynamic diameter and surface charge of the AuNPs were determined by DLS analysis and the spherical particles were visualized by TEM. MP@Alg-Ccm AuNPs exhibited improved cytotoxic potential against C6 glioma and MCF-7 cancer cell lines and was found to be highly hemocompatible. MP@Alg-Ccm AuNPs also exhibited active targeting efficiency against MCF-7 cancer cells due to the presence of "antifolate" drug MTX. Thus MP@Alg-Ccm AuNPs may find potential application in targeted combination chemotherapy for the treatment of cancer. The study is also interesting from the synthetic point of view because, here generation of AuNPs was done using "green chemical" alginate and dual drug conjugated AuNPs were created in two simple reaction steps using "green solvent" water., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
20. Collagen synthesis promoting pullulan-PEI-ascorbic acid conjugate as an efficient anti-cancer gene delivery vector.
- Author
-
Ambattu LA and Rekha MR
- Subjects
- Animals, Cell Line, Tumor, Collagen chemistry, DNA genetics, Gene Transfer Techniques, Genetic Therapy, Genetic Vectors genetics, Glioma genetics, Glioma therapy, Nanostructures chemistry, Rats, Ascorbic Acid chemistry, DNA administration & dosage, Genetic Vectors administration & dosage, Glucans chemistry, Polyethyleneimine chemistry, Transfection methods, Tumor Suppressor Protein p53 genetics
- Abstract
Cationized pullulan (pullulan-PEI; PP) was synthesized and further modified with an anti-oxidant molecule, ascorbic acid (PPAA) at various ratios. The nanoplexes formed at an optimum ratio of 4:1 was within a size of 150nm and had a zeta potential of 9-14mV. The nanoplexes at this ratio was used for further investigations. The cell internalization and transfection efficiency of these nanoplexes were determined in presence of serum. The internalization and transfection efficiency were found to be unaffected by the presence of fetal bovine serum. Another interesting observation was that this polymer was found to have collagen synthesis promoting property. The collagen synthesis effect of these polymers was quantified and observed that PPAA3 promoted the highest. Transfection efficiency was evaluated by assessing the p53 gene expression in C6 rat glioma cells and cell death was quantified to be 96% by flow cytometry, thus establishing the high efficacy of this polymer., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
21. Simultaneous Effect of Thiolation and Carboxylation of Chitosan Particles Towards Mucoadhesive Oral Insulin Delivery Applications: An In Vitro and In Vivo Evaluation.
- Author
-
Rekha MR and Sharma CP
- Subjects
- Administration, Oral, Animals, Blood Glucose analysis, Caco-2 Cells, Delayed-Action Preparations administration & dosage, Diabetes Mellitus, Experimental blood, Diabetes Mellitus, Experimental chemically induced, Diffusion, Humans, Insulin administration & dosage, Male, Nanocapsules administration & dosage, Nanocapsules ultrastructure, Particle Size, Rats, Rats, Wistar, Streptozocin, Thiomalates chemistry, Treatment Outcome, Chitosan chemistry, Delayed-Action Preparations chemistry, Diabetes Mellitus, Experimental drug therapy, Gastric Mucins chemistry, Insulin chemistry, Nanocapsules chemistry
- Abstract
Thiomalyl chitosan (TCS), a pH sensitive thiolated chitosan derivative, was developed and investigated towards oral protein delivery application. Particles of z-average 364 ± 5.6 nm with a negative zeta potential of 14.4 mV was obtained by tripolyphosphate cross linking of TCS. The release of insulin from TCS particles was significantly restricted at pH 1.2 minimizing up to about < 10% in 3 hours. The permeation enhancement ratio was found to 13 times higher than the FD4 alone and was 1.6 times higher than the unmodified chitosan particles. The protein protective properties of the matrix were established in presence of pepsin and pancreatic enzymes. Confocal microscopy studies proved the tight junction opening of Caco-2 cells by these thiolated chitosan particles and the in vivo studies on diabetic rats established its potential towards oral peptide delivery with pharmacological availability (PA) of 1.5%. The significance of this work is to establish that, the presence of multiple functional groups having similar property in the same matrix can improve its suitability as a promising candidate for oral peptide delivery with improved release characteristics, mucoadhesion as well as protecting the insulin activity and enhancing the permeability across the intestinal wall.
- Published
- 2015
- Full Text
- View/download PDF
22. Betaine conjugated cationic pullulan as effective gene carrier.
- Author
-
Ambattu LA and Rekha MR
- Subjects
- Animals, Cations, Cell Line, Humans, Nuclear Magnetic Resonance, Biomolecular, Polymers toxicity, Transfection, Betaine chemistry, Gene Transfer Techniques, Glucans chemistry, Polymers chemistry
- Abstract
Polyethyleneimne (PEI) is a very efficient transfecting agent but is toxic due to high charge density. To generate a vector which is efficient and less cytotoxic, PEI was conjugated with pullulan (PPEI). Further conjugation was done on PPEI with zwitter ionic betaine which possess antifouling property. PEI of molecular weight 1.2, 2, and 10 kDa were used in the study. Buffering capacity of pullulan-PEI-betaine (PPB) conjugates was found to be sufficient enough for the polymers to make endosomal escape. The polymers proved to be less cytotoxic and highly hemocompatible than PEI. Nuclear localization of YOYO tagged DNA was observed with the nanoplexes developed using PPEI and PPBs of PEI 10 kDa. Transfection efficiency was evaluated using p53 expressing gene and the live dead assay demonstrated very high transfection efficiency with PPB conjugates of PEI 10 kDa.
- Published
- 2015
- Full Text
- View/download PDF
23. Multifunctional polymeric nanoplexes for anticancer co-delivery of p53 and mitoxantrone.
- Author
-
Mitha AT and Rekha MR
- Abstract
Co-delivery of the anticancer drug, mitoxantrone (MTO) and the gene encoding tumor suppressor protein p53 was evaluated towards anticancer combinatorial therapy. The nanoplatforms developed herein are assembled by coupling β-cyclodextrin and the cationic polymer, polyethyleneimine to a hydrophilic polymer, pullulan (PPEICD). The β-cyclodextrin serves as a nanocontainer for the drug MTO, while the cationic moiety can condense pDNA. Acid base titrations provided insight into the buffering capacity of the PPEICD conjugate. Cytotoxicity studies by MTT assay in HepG2 and C6 cell lines and hemocompatibility studies confirmed the conjugate to be nontoxic and hemocompatible. In vitro release studies of MTO in phosphate buffered saline pH 7.4 showed an initial burst effect followed by a slow drug release. The released data fitted with the Korsmeyer-Peppas model and their diffusional exponents suggest that the drug release from the polymeric system followed diffusion and non-Fickian transport. Combined drug and gene loaded nanoplexes have a more apoptotic effect than either the drug or gene individually as confirmed by MTT assay and live dead assay. This indicated the significance of the combined drug and gene delivery system and the ability of the nanoplatform to overcome the multidrug resistance (MDR) of MTO. Moreover, preference of asialoglycoprotein receptor (ASGPR) mediated internalization for nanoparticle cellular uptake in HepG2 cell lines was identified by treating with the inhibitor asialofetuin. Cell studies in both HepG2 and C6 cell lines demonstrated that the nanoplatform PPEICD can efficiently and selectively deliver both p53 and MTO to cancer cells inducing high cell death.
- Published
- 2014
- Full Text
- View/download PDF
24. Carbonated fermented dairy drink - effect on quality and shelf life.
- Author
-
Ravindra MR, Rao KJ, Nath BS, and Ram C
- Abstract
Processing conditions were standardized for a carbonated sweetened fermented dairy beverage. The optimum level of carbonation for the beverage filled in 200 ml glass bottles was found to be at 50 psi pressure for 30 seconds. The beverage samples were stored under refrigerated conditions (7 °C) and evaluated at weekly intervals for their sensory, chemical and microbial quality. The uncarbonated control samples were found to keep well till 5 weeks of storage while the carbonated beverage was acceptable up to 12 weeks of storage. Carbonation did not significantly alter the pH of the beverage, while a marginal increase in titratable acidity was recorded for the carbonated samples. Carbonation was found to arrest the development of lipolysis and proteolysis in the beverage during storage. Microbiological investigations established the inhibition of yeast and mold growth due to dissolved CO2.
- Published
- 2014
- Full Text
- View/download PDF
25. Pullulan-protamine as efficient haemocompatible gene delivery vector: synthesis and in vitro characterization.
- Author
-
Priya SS, Rekha MR, and Sharma CP
- Subjects
- Calorimetry, Differential Scanning, DNA administration & dosage, Glucans administration & dosage, Hemolysis, In Vitro Techniques, Magnetic Resonance Spectroscopy, Native Polyacrylamide Gel Electrophoresis, Platelet Aggregation, Protamines administration & dosage, Spectroscopy, Fourier Transform Infrared, Transfection, Biocompatible Materials, Genetic Vectors, Glucans chemistry, Protamines chemistry
- Abstract
Biodegradable non-viral vectors with good transfection efficiency is essential for successful gene delivery. The purpose of this study was to design a non-viral vector by conjugating protamine to pullulan and elucidate the potential use of pullulan protamine conjugate (PPA) as an effective, non toxic and haemocompatible gene delivery system. The particle size and surface charge were measured using Nanosizer. Derivatization was confirmed by NMR, FTIR and DSC analyses. Acid base titration revealed the buffering behaviour of the conjugate. The protection of DNA from nuclease enzyme and interaction of plasma components on the stability of nanoplexes were also analysed. The uptake studies confirmed the plasmid delivery into the nucleus and the inhibitor studies determined the uptake mechanism. Transfection experiments revealed the capability of PPA to cellular uptake in C6 cells and facilitate high gene expression. Thus, PPA proves to be a promising non-viral vector., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
26. Extended shelf life flavoured dairy drink using dissolved carbon dioxide.
- Author
-
Ravindra MR, Rao KJ, Nath BS, and Ram C
- Abstract
Cardamom flavoured dairy beverage prepared using standardized method was carbonated in glass bottles. Carbonation at 50 psi pressure for 30 s was recommended. The pasteurized flavoured drink, carbonated or otherwise was evaluated for sensory, chemical and microbial quality during its refrigerated storage. The uncarbonated control samples were found to be sensorily acceptable up to 14 days, while the carbonated beverage remained acceptable up to 30 days. Carbonation of drink significantly affected the pH and acidity of product without reducing its acceptability. Carbonation resulted in inhibition of microbes, the effect was pronounced on psychrotrophic count. There was a linear but marginal increase in the pH of the carbonated samples till the 17(th) day of storage; the values diminished thereafter. The carbonated samples also had significantly reduced contents of FFA and soluble nitrogen compared to that of uncarbonated control samples as storage progressed beyond 10 days and this was attributed to inhibited microbial growth.
- Published
- 2014
- Full Text
- View/download PDF
27. Biomimetic mucin modified PLGA nanoparticles for enhanced blood compatibility.
- Author
-
Thasneem YM, Rekha MR, Sajeesh S, and Sharma CP
- Subjects
- Blood Cells drug effects, Blood Platelets drug effects, Cell Adhesion drug effects, Cell Proliferation, Cell Survival, Cells, Cultured, Enzyme-Linked Immunosorbent Assay, Humans, Lactic Acid chemistry, Particle Size, Polyglycolic Acid chemistry, Polylactic Acid-Polyglycolic Acid Copolymer, Surface Properties, Blood Coagulation drug effects, Lactic Acid pharmacology, Molecular Mimicry, Mucins chemistry, Nanoparticles chemistry, Polyglycolic Acid pharmacology
- Abstract
Efforts to develop long circulating polymeric nanoparticles have propelled many strategies in nanoparticle surface modification to bypass immune surveillance and systemic clearance. In this context, our present study reports on the preparation and evaluation of mucin functionalized poly lactic-co-glycolic acid (PLGA) nanoparticles as hemocompatible, cell penetrating nanoparticulate drug delivery system. Amino groups of mucin were conjugated to the terminal carboxylic acid groups on PLGA to be followed by nanoparticle synthesis via standard solvent evaporation technique. Detailed in vitro experiments were performed to illustrate the significance of alternating copolymer structured mucin modified PLGA nanoparticles in terms of enhanced hemocompatibility and cellular uptake. Mucylation proved promising in controlling PLGA nanoparticle- interaction with plasma proteins (opsonins) and blood components via hemolysis, thrombogenecity and complement activation. Besides hemocompatibility, the modified and unmodified nanoparticles were also found to be cytocompatible with L929 and C6 cell lines. The fluorescent and confocal image analysis evaluated the extent of cellular uptake of nanoparticles into C6 cells. Specifically the combination of stealth properties and cellular internalization capacity of mucin modified PLGA nanoparticle (PLGA-Mucin) lead us to propose it as a safe, efficient and multifunctional nanoplatform for disease specific intravenous drug delivery applications as far as in vitro experiments are concerned., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
28. Pullulan-histone antibody nanoconjugates for the removal of chromatin fragments from systemic circulation.
- Author
-
Rekha MR, Pal K, Bala P, Shetty M, Mittra I, Bhuvaneshwar GS, and Sharma CP
- Subjects
- Animals, Apoptosis, Cell Line, Cells, Cultured, Doxorubicin, Glucans chemistry, Hep G2 Cells, Humans, Immunoconjugates chemistry, Immunoconjugates immunology, Mice, Mice, Inbred BALB C, Nanoconjugates chemistry, Neutropenia chemically induced, Rats, Rats, Wistar, Sepsis immunology, Chromatin isolation & purification, Glucans therapeutic use, Histones immunology, Immunoconjugates therapeutic use, Nanoconjugates therapeutic use, Neutropenia drug therapy, Sepsis drug therapy
- Abstract
The billions of cells that die in the adult human body daily release considerable amounts of fragmented chromatin in the form of mono- and oligonucleosomes into the circulation in normal individuals, and in higher quantities in many disease conditions. Recent results suggest that circulating chromatin fragments (Cfs) especially from abnormal cells can spontaneously enter into healthy cells to damage their DNA and induce genomic instability. Furthermore, Cfs isolated from cancer patients may induce oncogenic transformation in the recipients' cells. Thus, it follows that if such Cfs emanating from apoptotic cells could be prevented from reaching other cells, it could potentially inhibit pathological conditions, including cancer. Here we have developed pullulan based histone antibody nanoconjugates for the removal of Cfs. Nanoconjugates were developed and various physico-chemical characterizations were carried out. The efficacy of these nanoconjugates on removing Cfs was evaluated both in vitro and in vivo. Our results indicate that nanoconjugates may have therapeutic value in the efficient removal of Cfs, reducing inflammation and fatality in a mouse model of sepsis, and in preventing neutropenia following treatment with Adriamycin., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
29. Oral delivery of therapeutic protein/peptide for diabetes--future perspectives.
- Author
-
Rekha MR and Sharma CP
- Subjects
- Administration, Oral, Animals, Exenatide, Humans, Incretins administration & dosage, Diabetes Mellitus, Type 2 drug therapy, Gastrointestinal Hormones administration & dosage, Hypoglycemic Agents administration & dosage, Insulin administration & dosage, Peptides administration & dosage, Venoms administration & dosage
- Abstract
Diabetes is a metabolic disease and is a major cause of mortality and morbidity in epidemic proportions. A type I diabetic patient is dependent on daily injections of insulin, for survival and also to maintain a normal life, which is uncomfortable, painful and also has deleterious effects. Extensive efforts are being made worldwide for developing noninvasive drug delivery systems, especially via oral route. Oral route is the most widely accepted means of administration. However it is not feasible for direct delivery of peptide and protein drugs. To overcome the gastro-intestinal barriers various types of formulations such as polymeric micro/nanoparticles, liposomes, etc. are investigated. In the recent years lot of advances have taken place in developing and understanding the oral peptide delivery systems. Simultaneously, the development and usage of other peptides having anti-diabetic potentials are also considered for diabetes therapy. In this review we are focusing on the advances reported during the past decade in the field of oral insulin delivery along with the possibility of other peptidic incretin hormones such as GLP-1, exendin-4, for diabetes therapy., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
30. Polymers for gene delivery: current status and future perspectives.
- Author
-
Rekha MR and Sharma CP
- Subjects
- Acrylates administration & dosage, Acrylates chemistry, Animals, Chitosan administration & dosage, Chitosan chemistry, DNA chemistry, Esters administration & dosage, Esters chemistry, Genetic Diseases, Inborn genetics, Genetic Diseases, Inborn therapy, Humans, Mice, NIH 3T3 Cells, Patents as Topic, Polyamines administration & dosage, Polyamines chemistry, Polyethyleneimine administration & dosage, Polyethyleneimine chemistry, DNA administration & dosage, Gene Transfer Techniques trends, Genetic Therapy, Polymers administration & dosage, Polymers chemistry
- Abstract
Gene therapy is a hope for curing many diseases and pathological conditions which are relatively difficult to treat. However lack of proper gene delivery vehicle is the main limiting step in this direction. Though viral vectors still lead as the major vehicle used in gene therapy clinical trials, their immunogenicity and low capacity restrict their wide use. Hence there is a need for developing non-viral vectors which can really be used for clinical applications. Polymers are a versatile group of molecules which can be modified and designed or engineered according to the end needs of the applications. The objective of this review is to summarize the recent advances in the development of polymeric vectors for gene delivery applications reported in patents and scientific journals.
- Published
- 2012
- Full Text
- View/download PDF
31. Unraveling the intracellular efficacy of dextran-histidine polycation as an efficient nonviral gene delivery system.
- Author
-
Thomas JJ, Rekha MR, and Sharma CP
- Subjects
- Animals, Cell Line, Tumor, Cell Nucleus drug effects, Cell Nucleus metabolism, Cell Proliferation drug effects, Cell Survival drug effects, Chemical Phenomena, Dextrans adverse effects, Electrophoretic Mobility Shift Assay, Endocytosis drug effects, Hep G2 Cells, Heparin chemistry, Histidine adverse effects, Humans, Nanostructures adverse effects, Neoplasms metabolism, Neoplasms pathology, Neoplasms therapy, Plasmids chemistry, Plasmids metabolism, Polyamines adverse effects, Polyelectrolytes, Rats, Dextrans chemistry, Gene Transfer Techniques adverse effects, Genes, p53, Histidine chemistry, Nanostructures chemistry, Plasmids administration & dosage, Polyamines chemistry
- Abstract
In this study, we attempted to elucidate the capability of a natural polymer dextran, by modification with histidine, to be an efficient, safe and promising nucleic acid delivery system in gene therapy. Physicochemical characterizations were performed to get an insight into the derivative. The efficiency of the derivative as a gene delivery vehicle was also studied in depth using fluorescence microscopy. Extensive efforts were made to have a better understanding of the cellular dynamics involved. The derivative proved itself to be 6.7-fold more excelling than PEI in its transfecting capability. Mechanisms underlying cellular internalization, vector unpacking, intranuclear localization and transgene expression were also investigated. The possibility of recruiting intracellular histone to promote the entry of the gene into the nucleus seemed promising. Our findings also explored the links that mediate the correlation between the uptake of the derivative and various endocytic pathways. The results thus obtained reflect the success of the entire journey of the synthesized delivery vehicle.
- Published
- 2012
- Full Text
- View/download PDF
32. Spermine grafted galactosylated chitosan for improved nanoparticle mediated gene delivery.
- Author
-
Alex SM, Rekha MR, and Sharma CP
- Subjects
- Drug Stability, Gene Transfer Techniques, Genetic Therapy methods, Hep G2 Cells, Humans, Magnetic Resonance Spectroscopy, Nanoparticles, Particle Size, Solubility, Spectroscopy, Fourier Transform Infrared, Transfection, Chitosan chemistry, Galactose chemistry, Genetic Vectors administration & dosage, Spermine chemistry
- Abstract
Despite multitude of beneficial features, chitosan has poor water solubility and transfection ability which affect its gene delivery efficacy. The two features are improved when certain chemical modifications are incorporated into the chitosan parent backbone. This strategy is adopted here, by coupling galactose and spermine into the chitosan backbone. The conjugation was determined with FTIR and (1)H NMR and nanoparticle morphology was assessed by TEM and AFM techniques. Particle size, zeta potential, buffering capacity and DNA binding ability gave encouraging result of enhanced solubility and stability. In vitro studies of GCSM in HepG2 cell lines displayed low cytotoxicity and improved transfection. We also identified the preference of receptor mediated internalization for nanoparticles cellular uptake by treating with cellular uptake inhibitors. The results evidently led us to comprehend that galactosylated chitosan-g-spermine could be considered as a promising chitosan derivative for conducting nanoparticle mediated gene delivery., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
33. Hemocompatible pullulan-polyethyleneimine conjugates for liver cell gene delivery: In vitro evaluation of cellular uptake, intracellular trafficking and transfection efficiency.
- Author
-
Rekha MR and Sharma CP
- Subjects
- Buffers, Cell Death drug effects, Complement Activation drug effects, Complement Activation immunology, DNA metabolism, Glucans chemical synthesis, Glucans chemistry, Hep G2 Cells, Hepatocytes drug effects, Humans, Intracellular Space drug effects, Liver metabolism, Magnetic Resonance Spectroscopy, Nanoparticles ultrastructure, Particle Size, Plasmids metabolism, Polyethyleneimine chemical synthesis, Polyethyleneimine chemistry, Static Electricity, Biocompatible Materials pharmacology, Glucans pharmacology, Hepatocytes metabolism, Intracellular Space metabolism, Liver cytology, Polyethyleneimine pharmacology, Transfection methods
- Abstract
Polyethyleneimine (PEI; 25 kDa)-conjugated pullulans (PPE1, PPE2 and PPE3) were developed and investigated for possible use in gene delivery applications. The cytotoxicity, blood component interactions such as red blood cell/white blood cell aggregation, platelet and complement activation, and protein interaction of the pullulan-conjugated PEI was drastically reduced in comparison to PEI-based nanocomplexes. Based on the blood compatibility studies, PPE1 was selected for further study. The buffering capacity of this derivative was similar to that of PEI, which plays an important role in efficient gene transfection. The particle size, zeta potential, stability in the presence of plasma and resistance to nuclease degradation were evaluated. In addition, cellular uptake and localization of plasmid, as well as transgene expression, were evaluated following in vitro transfection of HepG2 cells. Endocytosis inhibitors, confocal laser scanning microscopy and fluorescent labeling techniques were used to visualize the nanoplex uptake mechanism, cellular distribution and nuclear localization. The results from inhibitor experiments in the presence of asialofetuin indicated that the asialoglycoprotein receptor is involved in transfection of hepatocytes with pullulan-PEI complexes. The conjugation of pullulan with PEI did not hinder the plasmid nuclear localization ability of PEI. The transfection efficiency of pullulan conjugate was similar to PEI, with the added advantage of hemocompatibility and non-cytotoxicity. The transfection efficiency of PEI and PPE1 was 1.6- and 2-fold more, respectively, in the presence of serum than in the absence of serum. Therefore, the pullulan-PEI conjugate seems to be a promising gene delivery vector with good hemocompatibility and low toxicity but without compromising the transfection efficacy of PEI., (Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
34. Dextran-protamine polycation: an efficient nonviral and haemocompatible gene delivery system.
- Author
-
Thomas JJ, Rekha MR, and Sharma CP
- Subjects
- Animals, Cattle, Cell Line, Tumor, DNA chemistry, DNA genetics, Gene Transfer Techniques, Genetic Therapy methods, Hemolysis drug effects, Hep G2 Cells, Humans, Microscopy, Electron, Transmission, Nanostructures ultrastructure, Polyamines, Polyelectrolytes, Polymers chemistry, Polymers pharmacology, Spectroscopy, Fourier Transform Infrared, Transfection methods, Dextrans chemistry, Nanostructures chemistry, Protamines chemistry
- Abstract
Despite the remarkable progress in the field of gene therapy with viral vectors, nonviral vectors have attracted great interests due to their unique properties. Imparting desired characteristics to nonviral gene delivery systems requires the development of cationic polymers. The purpose of this work was to design a cationic derivative (Dex-P) of dextran using protamine in order to assert target specific cellular binding. Our objective was to elucidate the potential use of Dex-P as a haemocompatible, nontoxic and efficient nonviral candidate for gene therapy. Nanoplexes were prepared with calf thymus DNA and Dex-P. Derivatization was confirmed by FTIR, gel permeation chromatography and TNBS assay. Dynamic light scattering and TEM studies determined the size and morphology of the nanoplex. The buffering behaviour was assessed by acid base titration. Complexation stability was evaluated using agarose gel electrophoresis and EtBr displacement assay. The protection of ctDNA from nuclear digestion and the effect of plasma components towards stability of the nanoplexes were also analyzed. Various haemocompatible studies were performed to check haemolysis, aggregation, clotting time, and complement activation. Transfection and cytotoxicity experiments were performed in vitro. The nanosize, spherical shape and stability of nanoplexes were affirmed. Various experiments conducted confirmed Dex-P to be nontoxic and haemocompatible. Transfection experiments revealed the capability of Dex-P to facilitate high gene expression and cellular uptake in HepG2 cells. With the improved physicochemical, biological and transfection properties, Dex-P seems to be a promising gene delivery system., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
35. Dextran-glycidyltrimethylammonium chloride conjugate/DNA nanoplex: A potential non-viral and haemocompatible gene delivery system.
- Author
-
Thomas JJ, Rekha MR, and Sharma CP
- Subjects
- Animals, Cattle, DNA chemistry, DNA toxicity, Gene Transfer Techniques, Genetic Vectors, Hemolysis, Hep G2 Cells, Humans, Transfection, DNA administration & dosage, Dextrans chemistry, Epoxy Compounds chemistry, Nanoparticles, Quaternary Ammonium Compounds chemistry
- Abstract
Non-viral gene carriers have attracted great interests for their unique properties. Cationic polymers have been in focus nowadays. Dextran is one of the most widely studied polymer in terms of gene therapy and in vivo disposition. But its applications are limited by its own drawbacks. To overcome the drawback, we have modified dextran using glycidyltrimethylammonium chloride (GTAC) bearing cationic groups. Nanoplexes were prepared using the derivative and calf thymus DNA (ctDNA) by reducing the surface charge and size of ctDNA. Complexation and stability of the nanoplex was proved using agarose gel electrophoresis and by Ethidium bromide (EtBr) displacement assay. Acid base titration studies were done to determine its buffering capacity. Derivatization was confirmed using NMR. Protection of ctDNA from nuclease digestion was evaluated. Stability of the nanoplex towards plasma components was analyzed. Its interactions with blood components were tested by haemolysis and aggregation studies. In vitro cytotoxicity studies have been done to investigate the effect of nanoplex on HepG2 cells by MTT assay. This derivative has been proved to be feasible in transfection. The above investigations prove the capability of dextran modified with GTAC as a promising non-viral and haemocompatible gene delivery agent., (Copyright 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
36. Blood compatibility and in vitro transfection studies on cationically modified pullulan for liver cell targeted gene delivery.
- Author
-
Rekha MR and Sharma CP
- Subjects
- Animals, Cations, Humans, In Vitro Techniques, Magnetic Resonance Spectroscopy, Mice, Spectroscopy, Fourier Transform Infrared, Blood Grouping and Crossmatching, Glucans administration & dosage, Liver metabolism, Transfection
- Abstract
One of the major drawbacks of non-viral vector based gene delivery is the toxicity effects related to their positive charge. The aim of this work is to develop a cationic pullulan that can be used for gene delivery applications targeted to liver cells. Cationic groups were introduced by reacting varying amounts of glycidyl trimethyl ammonium chloride with pullulan. The cationic derivatives readily formed polyionic complexes with DNA and the size and zeta potential of these complexes were evaluated. The cytotoxicity and blood compatibility of cationic pullulan (CP) derivatives were assessed and compared to polyethyleneimine. Based on the cytotoxicity and blood compatibility test results CP3 was taken for further studies. Liver binding affinity of the modified pullulan CP3 was tested in vitro on hepatocytes and in vivo on mice. The complex was found to be stable in the presence of plasma as observed from gel retardation assay. This study focuses on the blood compatibility of the cationic pullulan, physico-chemical characterization and uptake of the nanocomplex by hepatocytes and in vitro transfection.
- Published
- 2009
- Full Text
- View/download PDF
37. Synthesis and evaluation of lauryl succinyl chitosan particles towards oral insulin delivery and absorption.
- Author
-
Rekha MR and Sharma CP
- Subjects
- Administration, Oral, Animals, Blood Glucose metabolism, Caco-2 Cells, Diabetes Mellitus, Experimental blood, Diabetes Mellitus, Experimental drug therapy, Drug Evaluation, Preclinical, Electric Impedance, Fluorescein-5-isothiocyanate analogs & derivatives, Humans, Hydrogen-Ion Concentration, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents metabolism, Insulin administration & dosage, Insulin analogs & derivatives, Insulin metabolism, Intestinal Mucosa metabolism, Jejunum metabolism, Male, Nanoparticles, Particle Size, Rats, Rats, Wistar, Streptozocin pharmacology, Time Factors, Chitosan chemistry, Drug Delivery Systems, Hypoglycemic Agents pharmacology, Insulin pharmacology, Intestinal Absorption drug effects
- Abstract
In this work a novel chitosan derivative, lauryl succinyl chitosan (LSC) was developed for the purpose of evaluating its applications towards oral peptide delivery system. Nano/microparticles were developed from this derivative by sodium tripolyphosphate (TPP) cross linking. Human insulin was used as the model protein drug and the release kinetics was studied at gastrointestinal pH. The presence of succinyl carboxyl groups had inhibitory effect on the release kinetics of insulin at pH 1.2 minimizing up to about 8.5+/-0.45% in two hours. Results showed that the presence of hydrophobic moieties controlled the release of the loaded insulin from the particles at intestinal pH. The particles were negatively charged with size ranging from 315 nm to 1.090 microm. The mucoadhesive capacity was established ex vivo using the jejunum of rat intestine. Confocal microscopy studies proved the tight junction permeability in Caco 2 cells and in vivo uptake of the FITC-insulin from loaded nanoparticles by the rat intestinal epithelium. The results demonstrated that the modified chitosan with both hydrophilic (succinyl) and hydrophobic (lauryl) moieties had improved the release characteristics, mucoadhesivity as well as the permeability of the insulin compared to the native chitosan particles. The LSC2 particles were capable of reducing blood glucose levels in diabetic rats for the duration of about 6 h. This indicated that this novel derivative could be a promising candidate for oral peptide delivery.
- Published
- 2009
- Full Text
- View/download PDF
38. Oxidative stress in sepsis in children.
- Author
-
Cherian S, Jameson S, Rajarajeswari C, Helena V, Latha L, Anu Rekha MR, Nagamma T, Subba Raju V, Kini PG, and Rao A
- Subjects
- Ascorbic Acid blood, Child, Preschool, Glutathione blood, Humans, Lipid Peroxidation immunology, Statistics, Nonparametric, Superoxide Dismutase blood, Thiobarbituric Acid Reactive Substances analysis, Oxidative Stress immunology, Sepsis immunology
- Abstract
Background & Objective: Information on oxidative damage during sepsis in children is not available, we undertook this study to assess the levels of certain antioxidants in blood of children with sepsis., Methods: Study group had 38 children with sepsis (<5 yr) and 39 age-and sex-matched controls admitted to a tertiary care hospital. Red cell glutathione (GSH), superoxide dismutase (SOD) and thiobarbituric acid reactive substance (TBARS) and plasma vitamin C were estimated by standard techniques., Results: There was no significant change in erythrocyte GSH, SOD and TBARS levels in sepsis when compared to controls. This may be due to the adaptive response of the body to combat the oxidative stress. However, plasma vitamin C levels were significantly reduced in patients aged one year one month to five years which may be due to active phagocytosis and due to its role as a free radical scavenger., Interpretation & Conclusion: Our findings show that children affected by sepsis probably adapt to the free radical toxicity induced by this condition. Further studies need to be done on a larger sample to confirm the findings.
- Published
- 2007
39. Alpha-amylase inhibitor changes during processing of sweet potato and taro tubers.
- Author
-
Rekha MR and Padmaja G
- Subjects
- Flour analysis, alpha-Amylases metabolism, Colocasia chemistry, Cooking methods, Enzyme Inhibitors metabolism, Hot Temperature, Ipomoea batatas chemistry, alpha-Amylases antagonists & inhibitors
- Abstract
Alpha-amylase inhibitor changes during processing of sweet potatoes (Ipomoea batatas) and taro (Colocasia esculenta) indicated that varietal differences profoundly influence the thermal inactivation profile. The alpha-amylase inhibitors of taro were almost totally inactivated during oven drying of the chips at 90 degrees C and 100 degrees C for 24 h, while 0.8-10% activity was retained in sweet potato chips under the same conditions. Relatively better thermal stability was exhibited by the sweet potato amylase inhibitors at lower temperatures (70 and 80 degrees C) as well. Cooking by boiling the tuber pieces in water resulted in retention of 29-59% amylase inhibitor in sweet potato and 11-16% in taro. Microwave baking was a better method for inactivation of amylase inhibitors in these tubers. Flour prepared from the tubers retained only trivial amounts of the inhibitor.
- Published
- 2002
- Full Text
- View/download PDF
40. Immunomodulation of excretory secretory materials from the filarial parasiteSetaria digitata.
- Author
-
Raj RK, Pradeep CG, Devi CM, John L, Rekha MR, and Oommen SK
- Abstract
ES materials released along with the release of mf showed immunosuppression as evidenced by a decrease in T lymphocyte levels in the immunised animals. Lipid fractions of the mf associated ES materials and protein fractions of the detergent soluble materials were found to cause suppression of immune response in the host. Further study revealed that the suppression associated with the lipid fractions is actually the end result and that mf associated ES materials is actually a mixture of immunosuppressive and immunopotentiating components and the release of the components is most likely regulated.
- Published
- 1997
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.