Over the past few decades, metal nanoparticles less than 100 nm in diameter have made a substantial impact across diverse biomedical applications, such as diagnostic and medical devices, for personalized healthcare practice. In particular, silver nanoparticles (AgNPs) have great potential in a broad range of applications as antimicrobial agents, biomedical device coatings, drug-delivery carriers, imaging probes, and diagnostic and optoelectronic platforms, since they have discrete physical and optical properties and biochemical functionality tailored by diverse size- and shape-controlled AgNPs. In this review, we aimed to present major routes of synthesis of AgNPs, including physical, chemical, and biological synthesis processes, along with discrete physiochemical characteristics of AgNPs. We also discuss the underlying intricate molecular mechanisms behind their plasmonic properties on mono/bimetallic structures, potential cellular/microbial cytotoxicity, and optoelectronic property. Lastly, we conclude this review with a summary of current applications of AgNPs in nanoscience and nanomedicine and discuss their future perspectives in these areas.

https://www.mdpi.com/1422-0067/20/4/865/pdf

Silver Nanoparticles: Synthesis and Application for Nanomedicine

Characterization of silver nanoparticles synthesized using Urtica dioica Linn. leaves and their synergistic effects with antibiotics

Ongoing advances in nanotechnology research have established a variety of methods to synthesize nanoparticles (NPs) from a diverse range of materials, including metals, semiconductors, ceramics, metal oxides, polymers, etc. Depending upon their origin and synthesis methods, NPs possess unique physicochemical, structural and morphological characteristics, which are important in a wide variety of applications concomitant to electronic, optoelectronic, optical, electrochemical, environment and biomedical fields. This review provides a comprehensive overview on various physical, chemical and bio-assisted methods largely employed to synthesize and fabricate NPs of varying size, surface characteristics, functionalities and physicochemical behavior. The key applications of nanoparticles have also been discussed.

Methods and strategies for the synthesis of diverse nanoparticles and their applications: a comprehensive overview

Enzymatic biodiesel: Challenges and opportunities

The role of activated charcoal in plant tissue culture.

Multiple shoots were induced from seedling and axillary buds of mature plants of Dendrocalamus strictus on Murashige and Shoog's medium supplemented with BA and kinetin. About 35–45 shoots were obtained within 20–25 days from a nodal explant of seedling and 3–8 shoots were obtained from a nodal explant of mature plants in the primary culture. The seedling derived cultures were separated into groups of 5–7 and transferred to fresh subculture medium. Rooting of the shoots was achieved under in vitro and ex vitro conditions. 85–90% of rooting was achieved by the ex vitro method using IBA.

In vitro shoot propagation of Dendrocalamus strictus nees

The present study was undertaken to develop efficient transformation protocol for cucumber cv. Poinsett 76 using Agrobacterium strain EHA 105. Five-day-old mature cotyledon explants was used for transformation study. The infected explants were co-cultivated for 2 days in MS medium containing BA (1.0 mg Lˉ1). The selection of transformed shoots was carried out in MS medium fortified with BA (1.0 mg Lˉ1), Cefotaxime (300 mg Lˉ1) and PPT (2.0 mg Lˉ1). The transformed shoots were elongated in MS medium containing BA (1.0 mg Lˉ1), Cefotaxime (300 mg Lˉ1), PPT (2.0 mg Lˉ1) along with GA3 (0.5 mg Lˉ1). The rooting of elongated shoots was achieved in MS medium with BA (1.0 mg Lˉ1), Cefotaxime (300 mg Lˉ1), PPT (2.0 mg Lˉ1) and IBA (0.6mg Lˉ1). The transient GUS expression assay and leaf disc assay were carried out in order to find transformed shoots. The molecular confirmation of transformed shoots revealed the foreign gene integration into cucumber genome.

Agrobacterium-mediated Genetic Transformation in Cucumber (Cucumis sativus L.)

Somatic embryogenesis was achieved from immature cotyledon derived callus of mungbean, Vradiata (L) Wilczek in MS liquid medium Embryogenic callus was induced on MS medium with NAA (5 mg/L) Differentiation of somatic embryos was observed when embryogenic callus was transferred to MS liquid medium containing 2,4-D (15 mg/L) and L-proline (50 mg/L) The torpedo shaped embryos were transferred to MS liquid medium with BAP and ABA (1 mg/L each) for maturation and germination Fifty per cent of torpedo shaped embryos were converted into tiny plants (8-9 plants out of 17) after one week of culture The germinated embryos were isolated and transferred to MS half strength basal (solid) medium for further development

/pdf/somatic-embryogenesis-in-vigna-radiata-l-wilczek-1txo8o4wyk.pdf

Somatic embryogenesis in Vigna radiata (L.) Wilczek.

Regeneration of transformed plants from the Agrobacterium-infected tissue is a time-consuming process and requires hard work. Okra [Abelmoschus esculentus (L.) Moench] is highly recalcitrant to Agrobacterium-mediated genetic transformation and regeneration. In this study, we established a tissue culture-independent genetic transformation system for okra using seed as an explant. Agrobacterium tumefaciens EHA 105 harbouring the binary vector pCAMBIA 1301–bar was used to infect the okra seeds. Various parameters influencing the okra genetic transformation including, co-cultivation duration, acetosyringone, sonication, and vacuum infiltration have been evaluated. Maximum transformation efficiency of 18.3 % was recorded when the pre-cultured okra seeds were sonicated for 30 min and vacuum infiltrated for 3 min in Agrobacterium suspension containing 100 µM acetosyringone and co-cultivated for 3 days on a medium containing 100 µM acetosyringone. The GUS histochemical analysis confirmed the gus A gene integration and expression, whereas polymerase chain reaction (PCR) and Southern blot hybridization confirmed the bar gene integration and copy number in the transformed okra genome. The transgene was successfully segregated into the progeny plants with a Mendelian inheritance ratio of 3:1. The in planta transformation protocol developed in the present investigation is applicable to transform the okra plants with disease-resistant traits, and the transformed plants can be generated within 60 days.

Assessment of factors influencing the tissue culture-independent Agrobacterium -mediated in planta genetic transformation of okra [ Abelmoschus esculentus (L.) Moench]

Enhanced numbers of multiple shoots were induced from shoot tip explants of cucumber. The effects of amino acids (leucine, isoleucine, methionine, threonine, and tryptophan) and polyamines (spermidine, spermine, and putrescine) along with benzyladenine (BA) on multiple shoot induction were investigated. A Murashige and Skoog (MS) medium containing a combination of BA (4.44 μM), leucine (88 μM), and spermidine (68 μM) induced the maximum number of shoots (36.6 shoots per explant) compared to BA (4.44 μM) alone or BA (4.44 μM) with leucine (88 μM). The regenerated shoots were elongated on the same medium. Elongated shoots were transferred to the MS medium fortified with BA (4.44 μM), leucine (88 μM), and putrescine (62 μM) for root induction. Rooted plants were hardened and successfully established in soil with a 90% survival rate.

Andy Ganapathi

Papers

In vitro shoot propagation of Dendrocalamus strictus nees

Agrobacterium-mediated Genetic Transformation in Cucumber (Cucumis sativus L.)

Somatic embryogenesis in Vigna radiata (L.) Wilczek.

Assessment of factors influencing the tissue culture-independent Agrobacterium -mediated in planta genetic transformation of okra [ Abelmoschus esculentus (L.) Moench]

Leucine and spermidine enhance shoot differentiation in cucumber ( Cucumis sativus L.)