Preparation and physicochemical assessment of bioactive films based on chitosan and starchy powder of white turmeric rhizomes (Curcuma Zedoaria) for green packaging applications.

In the current study, the bioactive films of chitosan/white turmeric (CH/WT) were prepared by employing solvent casting technique and analyzed their physicochemical and biological properties for active packaging applications. The successful inclusion of white turmeric into the chitosan matrix is confirmed by Fourier Transform Infrared Spectroscopy. Due to the presence of hydrogen bonding interaction, the active films exhibited good tensile properties, smooth surface morphology, miscibility, water resistance and UV barrier properties. The incorporation of white turmeric reduced the water vapour transmission rate and oxygen permeability (p < 0.05) in contrast with pristine film. The prepared blend films revealed soil degradation rate more than 60% within 15 days. Furthermore, the blend films exhibited lesser water solubility, moisture content and swelling index after addition of white turmeric to chitosan (p < 0.05). The prepared films revealed extensive antimicrobial activity against gram positive and gram negative bacteria. The antioxidant activity and total phenolic content were improved upon the incorporation of white turmeric. Moreover, the oil absorption rate of the blend films was decreased by 46% in comparison with pristine film. Overall, white turmeric incorporated chitosan films were employed as a green packaging material to extend the shelf life of the foodstuff.

Smart biodegradable films based on chitosan/methylcellulose containing Phyllanthus reticulatus anthocyanin for monitoring the freshness of fish fillet.

The current work aims to prepare biologically active and pH responsive smart films based on Chitosan (CS)/Methylcellulose (MC) matrix integrated with Phyllanthus reticulatus (PR) ripen fruit anthocyanin. The prepared smart films (CMPR) were fabricated through a cost-effective solvent casting technique. The existences of secondary interactions were confirmed by the FT-IR analysis. The smooth SEM images revealed the miscibility and compatibility of the CS/MC matrix with PR anthocyanin. The incorporation of PR anthocyanin significantly blocked the UV light transmission of the CS/MC films while slight decrease in the transparency was observed. The water solubility, moisture retention capacity, and water vapor transmission rate were significantly enhanced with an increase in the PR anthocyanin content. Additionally, the prepared CMPR smart films showed pink color in acidic pH while yellowish in basic pH solution and further exhibited strong antioxidant activity as well as antibacterial activity against the common foodborne pathogens such as S. aureus, P. aeruginosa, and E. coli. The CMPR smart film also displayed potential result for monitoring the fish fillet freshness at room temperature. The results proclaim that the prepared CMPR smart films could be utilized for quality assurance as well as shelf life extension of the marine food products.

Production and characterization of monospecific and bispecific antibodies against dengue virus NS1 protein.

Dengue is a mosquito borne infection, which in recent years has become a major international public health concern. Annually, 100 million dengue virus infections are reported worldwide. The nonstructural protein 1 (NS1) of dengue virus is a useful target for diagnostics of dengue infection since the protein is abundantly circulating in the blood during acute phase of the disease, in both primary and secondary infections. This research paper highlights the development of a panel of Mab and bsMab for dengue NS1 detection. The P148 series of Mabs showed high specificity for recombinant dengue NS1 antigen. These antibodies showed no cross reactivity with recombinant dengue envelope protein and other viral proteins. The hybrid-hybridoma approach to generate the P156.1 and P156.2 bsMabs from the P148 monoclonal antibody method was used during this study. Furthermore, the affinity purification provided good yields of quadromas associated with HRPO in two steps. Direct detection method involved coating of plates with different concentrations of recombinant antigen and detecting with bsMab. Sensitive sandwich assay with Mabs and bsMabs was also done. Detection of nonstructural dengue antigens may be of benefit for early and rapid diagnosis of dengue infection due to their long half-life in the blood.

Heterosandwich immunoswab assay for dengue virus Ns1 antigen detection.

Dengue and the more severe dengue hemorrhagic fever have been a very critical public health problem globally. Millions of people especially in the tropical areas get infected with dengue. An efficient diagnostic is very important for early screening of dengue infection. In dengue-infected patients, the nonstructural protein NS1 is present on the surface of infected cells and secreted in plasma. The NS1 antigen is an important target for developing a quick diagnostic largely due to its long presence in the blood. We have developed a simple-to-use immunoswab-based diagnostic procedure employing monoclonal antibodies and the second-generation quadromas. The detection limit for NS1 has been established to be in the subnanogram range. The assay is very sensitive, has a visual end point, and also being extremely inexpensive. With this assay, screening time for a dengue-infected person would be very rapid.

Enhanced prokaryotic expression of dengue virus envelope protein.

PURPOSE: To highlight the expression and purification of the recombinant dengue virus type-1 antigen exploiting the codon optimized full length envelope for increased yield in E. coli. METHODS: A 6x His tag was inserted at the C terminus to facilitate purification. The purified protein was recognized in Western blot by Monoclonal antibody specific for the tag. The in vitro refolded recombinant protein was used to immunize mice for the development of hybridomas and also analyzed for its biological functionality with heparan sulfate binding assay. RESULTS: The polyclonal anti-sera from the immunized mice were found to recognize the envelope protein thereby establishing the immunogenicity of the protein. CONCLUSION: The purified envelope protein could potentially be used towards dengue diagnostics and vaccine development efforts. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Gene delivery system: a developing arena of study for the new era of medicine.

Gene therapy concept has been being overcome massive challenges from 1972 in ethical, socio-economical and developmental issues. In this review, we have attempted to go through almost all the arenas and described in a methodical way that reflects not only the initial ethical and scientific thoughts but also adorned a solid depiction of gene therapy related physico-chemical barriers, approaches and strategies till to date.

Overview of plant-derived vaccine antigens: Dengue virus.

This review highlights the advantages and current status of plant-derived vaccine development with special reference to the dengue virus. There are numerous problems involved in dengue vaccine development, and there is no vaccine against all four dengue serotypes. Dengue vaccine development using traditional approaches has not been satisfactory in terms of inducing neutralizing antibodies. Recently, these issues were addressed by showing a very good response to inducing neutralizing antibodies by plant-derived dengue vaccine antigens. This indicates the feasibility of using plant-derived vaccine antigens as a low-cost method to combat dengue and other infectious diseases. The application of new methods and strategies such as dendritic cell targeting in cancer therapy, severe acute respiratory syndrome, tuberculosis, human immune deficiency virus, and malaria might play an important role. These new methods are more efficient than traditional protocols. It is expected that in the near future, plant-derived vaccine antigens or antibodies will play an important role in the control of human infectious diseases.

Micropropagation of Dendrobium nobile from shoot tip sections.

Successful shoot regeneration of Dendrobium nobile was achieved using thin shoot tip sections and triacontanol (TRIA) for the first time. Protocorm-like bodies (PLBs) or proliferating shoot buds were observed when thin shoot tip sections were cultured on the basal medium of Mitra et at. (Indian J. Exp. Biol. 14 (1976) 350) supplemented with 4.0 microg L(-1) TRIA. The highest percentage of explants (93%) produced PLBs or proliferating shoot buds (21) at 4.0 microg L(-1) TRIA-supplemented basal medium. All the newly formed PLBs or proliferating shoot buds survived and ultimately produced healthy shoots with 2-3 leaves. Shoots produced roots when cultured on basal medium supplemented with 2.0 microg L(-1) TRIA. The well-rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1), and a 92% survival rate was achieved. This work reveals that TRIA can be used as an effective growth regulator in the micropropagation and conservation of D. nobile.

Somatic embryogenesis from vegetative shoot apices of mature trees of Pinus patula.

Embryogenic cultures were initiated and established from apical shoots of mature trees of three genotypes of Pinus patula Scheide et Deppe. Factors affecting initiation, including cold pretreatment, basal medium composition, growth regulators and gelling agent concentration, and the effect of partial desiccation on somatic embryo maturation were investigated. Cold pretreatment of thick sections (0.5-1.0 mm) of apical shoots at 2 degrees C for 3 days on 0.3% activated charcoal induced white mucilaginous embryogenic callus on initiation medium. Subculture of this embryogenic callus on maintenance medium resulted in the formation of embryonal suspensor masses with proembryos. Partial desiccation (12-90 h) of embryogenic tissue at the proembryo stage of development, prior to transfer to maturation medium containing 9 g l(-1) Gellan gum, enhanced somatic embryo maturation and germinability. The frequency of maturation increased from 5.3 to 16.5% after 12 h of desiccation and from 16.5 to 73.8% after 24 h of desiccation, but longer periods of desiccation were ineffective.