Membrane supported scaffold : architectures for tissue engineering

Tissue engineering aims at restoring or regenerating a damaged tissue. Often the tissue recreation occurs by combining cells, derived from a patient biopsy, onto a 3D porous matrix, functioning as a scaffold. One of the current limitations of tissue engineering is the inability to provide sufficient nutrient and oxygen supply in developing 3D in-vitro culture. In human body the vasculature is embedded into almost every tissues and organs. They transport blood, and thus nutrients and waste products, to and from almost any part of the body. It is a critical template for the exchange of gas, nutrients, cells or molecules and a regulator of tissue development. Insufficient vascularization within the construct results in nutrient limitations, which in-turn results in suboptimal integration of, and cell death in tissue engineered constructs. \ud This thesis explores a new approach by integrating semi-permeable porous hollow fiber membrane in to tissue engineered scaffolds to mimic capillary network. The rationale of this method is that the hollow fibers integrated within the tissue engineered scaffolds would supply required nutrients and gases through the walls of the fiber during in-vitro perfusion bioreactor culture. Furthermore, the same approach is used to develop 3D multilayer tissue using bottom-up process by rolling pre-seeded electrospun (ES) sheets around multibore hollow fiber. The rolling of pre-seeded ES sheet to form multilayer constructs achieves uniform cell distribution in the scaffold and has a marked potential to form functional tissue composed of multiple cell types. This thesis also presents the development of biodegradable hollow fiber membrane of poly (L-lactic acid) (PLLA), suitable for nutrient perfusion and illustrates the effect of scaffold surface structure and curvature which plays a critical role in cell adhesion and proliferation in dynamic culture conditions

Diversity and extracellular enzyme activities of fungal endophytes isolated from medicinal plants of Western Ghats, Karnataka

A total of 112 endophytic fungi belonging to 26 genera were isolated from six wild medicinal plants belonging to Bisle region, Western Ghats of Karnataka, among which Hedychium flavescens Carey ex Roscoe and Hedychium coronarium J. Koenig are listed as endangered plants in the Red data book. The endophytic fungal diversity and extracellular enzyme activity from the endangered plants are reported for the first time. The diversity of the fungal isolates was analyzed using Simpson’s diversity indices, Shannon–Weiner index and Evenness. The fungal isolates were screened for the production of extracellular enzymes, of which 29% were positive for amylase, 28% for cellulase, 18% for pectinase and 40% for asparaginase activity. None of the endophytic isolates depicted laccase activity

A kinetic analysis of the tumor-associated galactopyranosyl-(1→3)-2-acetamido-2-deoxy-α-D-galactopyranoside antigen-lectin interaction

A kinetic study of the tumor-associated galactopyranosyl-(1→3)-2-acetamido-2-deoxy-α-D-galactopyranoside (T-antigen) with lectin peanut agglutinin is described. The disaccharide antigen was synthesized by chemical methods and was functionalized suitably for immobilization onto a carboxy-methylated sensor chip. The ligand immobilized surface was allowed interaction with the lectin peanut agglutinin, which acted as the analyte and the interaction was studied by the surface plasmon resonance method. The ligand-lectin interaction was characterized by the kinetic on-off rates and a bivalent analyte binding model was found to describe the observed kinetic constants. It was identified that the antigen-lectin interaction had a faster association rate constant (ka1) and a slower dissociation rate constant (kd1) in the initial binding step. The subsequent binding step showed much reduced kinetic rates. The antigen-lectin interaction was compared with the kinetic rates of the interaction of a galactopyranosyl-(1→4)-β -D-galactopyranoside derivative and a mannopyranoside derivative with the lectin

Phytochemical Screening and in Vitro Assessment of Antimicrobial and Antioxidant Potential of Andrographis Serpyllifolia-An Endemic Medicinal Plant from South India

The current study was aimed to investigate the phytochemical composition, antibacterial and antioxidant activity of A. serpyllifolia plant extracts. Phytochemical screening revealed the presence of alkaloid, tannins, steroids, terpenoids, phlobatannin, anthraquinones flavonoids, saponins and phenolic compounds. Quantitative analysis revealed the presence of saponins (4.2%) in high concentration followed by tannins (4.12%), phenolics (1.4%), alkaloids (1.2%) and flavonoids (0.98%). This study will provide phytochemical information for preparation of concentrated and effective extract of A. serpyllifolia. Petroleum ether, chloroform, benzene and methanol extracts of shade dried plant parts of A. serpyllifolia were tested for antibacterial activity against six strains of bacterial species, viz., Bacillus subtilis, Escherichia coli, Proteus, Pseudomonas aeruginosa, Klebsiella sps and Staphylococcus aureus using the standard agar disk diffusion method. All the extracts have shown significant activity against tested microbes with the inhibition zone ranged of 5.7-16.8mm. Among various solvent extracts studied petroleum ether extract showed a highest antibacterial activity followed by methanol, benzene, chloroform. Antioxidant potential of methanol extracts was determined by DPPH and ABTS free radical scavenging assay. The extracts showed a very good antioxidant property and the IC50 value was found to 268.12ìg/ml for DPPH assay and 398.46ìg/ml for ABTS assay. Ascorbic acid taken as control showed highest antioxidant power in the present study. The results suggest that A. serpyllifolia has promising antioxidant activity and could serve as potential source of natural antioxidant

An efficient reconfigurable workload balancing scheme for fog computing network using internet of things devices

Nowadays a huge amount of data has been communicated using fog nodes spread throughout smarty cities. the communication process is performed using fog nodes which are co-located with cellular base stations (BSs) that can move the computing resources close to internet of things (IoT) devices. In smart cities, a different type of data flow has been communicated through IoT devices. The communication process performs efficiently using the remote cloud. The IoT devices very close to the BS can communicate data without using fog nodes. Due to these phenomena, workload unbalancing occurs in IoT devices communicating in fog computing networks. Hence, it generates communication and computing latency. The task distribution process between the IoT devices is unbalanced. Hence, congestion and loss of information occur in fog computing network. A proposed reconfigurable load balancing algorithm (RLBA) is efficiently balancing the workload by reconfigurable communication channels and deviates the task with respect to the BS locations, IoT devices density and load IoT devices in each fog nodes in a network to minimize the communication and computing latency. As per the performance analysis, the proposed algorithm shows better performance as compared to conventional methods’ average latency ratio, communication latency ratio, computing load and traffic load

Influence of Growth Factors on Pigmentation of Chaetomium Cupreum SS-02 and the Antibacterial Efficacy of the Pigment against Ralstonia Solanacearum

An extracellular pigment-producing ascomycetous filamentous fungus Chaetomium was isolated from litter sample and identified as Chaetomium cupreum SS-02. The optimal growth conditions for high pigment yield and the invitro antagonistic activity of the pigment against Ralstonia solanacearum – a phytopathogenic bacterium, was investigated. The optimal culture conditions for pigment production were as follows; Dextrose 2%, Peptone + Yeast extract (0.4%), pH 6, temperature 35°C and inoculum age - 6 days old. The invitro screening of antibacterial activity of the pigment against five pathogenic strains of Ralstonia solanacearum was measured in terms of zone of inhibition. The highest activity was recorded against RS4 strain

Induction of Systemic Resistance by Trichoderma Asperellum against Bacterial Wilt of Tomato Caused by Ralstonia Solanacearum

Trichoderma asperellum was used as a biological control agent against bacterial wilt disease caused by Ralstonia solanacearum. The present investigation is focused on the role of defense- related enzymes in imparting resistance to tomato against bacterial wilt pathogen Ralstonia solanacearum. Two isolates of Trichoderma asperellum (T4 and T8) exhibiting high antagonistic activity against a virulent strain of Ralstonia solanacearum (RS) were selected during screening for studies on several biocontrol mechanisms under greenhouse conditions. Seed treatment with T. asperellum isolates significantly improved the quality of seed germination and seedling vigor. Efficacy of T4 and T8 isolates, evaluated under greenhouse conditions exhibited suppression by about 50% in disease incidence of bacterial wilt and promoted growth in tomato plant. The isolates T4 and T8 were further tested for their ability to induce the production of defense-related enzymes in plants. The seed application with T4 and T8 isolates induced a significant increase in the activities of peroxidase (POX), Polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), and â.1, 3-glucanase in treated tomato plants. Increased activities of phenylalanine ammonia lyase, peroxidase, Polyphenol oxidase, â-1, 3-glucanase were observed in T4 and T8 pre-treated tomato plants challenged with Ralstonia solanacearum. Trichoderma asperellum treatment also triggered the defense related enzymes involved in synthesis of phenols. Higher accumulation of phenolics was noticed in plants pre-treated with T4 and T8 challenged with Ralstonia solanacearum. Native PAGE analysis of both peroxidase (POX) and Polyphenol oxidase (PPO) was carried out for the time course of enzyme activities. The present study shows that in addition to direct antagonism and plant growth promotion; induction and increased activity of defense related enzymes involved in the phenyl propanoid pathway collectively contributed to enhanced resistance against invasion of bacterial wilt in tomato caused by Ralstonia solanacearum

Optimization of physiological conditions for L-asparaginase production by endophytic fungi (Fusarium solani) isolated from Tinospora cordifolia (Willd.) Hook. F & Thomson

Asparaginase converts L-asparagine to L-aspartic acid and has received considerable attention in the recent years for its anti-carcinogenic potential. In the present investigation, the endophytic fungi isolated from T. cordifolia were screened for the production of extracellular L-asparaginase during their growth on Modified Czapekdox medium (MCD). The physical and nutritional conditions were optimized for maximum production of L-asparaginase by F. solani under submerged fermentation conditions (SmF). The fungi exhibited significant variations in the production of L-asparaginase under the influence of incubation period, temperature, pH, carbon and nitrogen sources. It was observed that maximum enzyme activity was recorded on the 6th day of incubation period at pH 7.0 with an incubation temperature of 30°C at 120 rpm. Sucrose (0.2%) was the best carbon source. Different nitrogen sources at concentrations ranging from 0.1% to 0.5% were assessed. Among them, ammonium nitrate (0.4%) and sodium nitrate (0.4%) showed maximum production of L- asparaginase

A comprehensive study of noninfectious neurological disorders of Bovine

Call number: LD2668 .R4 1964 M98