Gayathri Vijayakumar

Dr. Gayathri Vijayakumar

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 January 2023 in Antibiotics
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GVGayathri Vijayakumar
Gayathri Vijayakumar
Hyung Joo KimHyung Joo Kim
Hyung Joo Kim
SRSENTHIL KUMARAN RANGARAJULU
SENTHIL KUMARAN RANGARAJULU
The prospective application of probiotics is an adjuvant for the advancement of novel antimicrobial and wound-healing agents. Currently, probiotic bacteria are utilized for the biosynthesis of nanoparticles in the development of innovative therapeutics. The present study aimed at using nanoparticle-conjugated probiotic bacteria for enhanced antibacterial and wound-healing activity. In the present investigation, the probiotic bacteria were isolated from a dairy source (milk from domestic herbivores). They screened for antibacterial activity against infection-causing Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Bacillus subtilis and Staphylococcus aureus) pathogens. Further, the probiotic strain with higher bactericidal activity was used to synthesize silver, selenium, and copper nanoparticles. The isolated strain was found to be Lactiplantibacillus plantarum and it only has the ability to synthesize silver nanoparticles. This was verified using Ultra violet-Visible (UV-Vis) spectroscopy, where the test solution turned brown and the greatest UV-Vis absorptions peaked at 425 nm. Optimization studies on the synthesis of AgNPs (silver nanoparticles) are presented and the results show that stable synthesis was obtained by using a concentration of 1mM silver nitrate (AgNO3) at a temperature of 37 °C with pH 8. The FTIR (Fourier transform infrared spectroscopy) study confirmed the involvement of functional groups from the cell biomass that were involved in the reduction process. Additionally, biosynthesized AgNPs showed increased antioxidant and antibacterial activities. The nano silver had a size distribution of 14 nm and was recorded with HR-TEM (high-resolution transmission electron microscopy) examination. The EDX (energy dispersive X-ray) analysis revealed 57% of silver groups found in the nanoparticle production. The biosynthesized AgNPs show significant wound-healing capabilities with 96% of wound closure (fibroblast cells) being observed through an in vitro scratch-wound assay. The cytotoxic experiments demonstrated that the biosynthesized AgNPs are not extremely hazardous to the fibroblast cells. The present study provides a new platform for the green synthesis of AgNPs using probiotic bacteria, showing significant antibacterial and wound-healing potentials against infectious pathogens.

Verified
Journal Article
Open access
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GVGayathri Vijayakumar
Gayathri Vijayakumar
Hyung Joo KimHyung Joo Kim
Hyung Joo Kim
JJJEONG WOOK JO
JEONG WOOK JO
SRSENTHIL KUMARAN RANGARAJULU
SENTHIL KUMARAN RANGARAJULU
Recently, the utilization of biological agents in the green synthesis of nanoparticles has been given interest. In this study, silver nanoparticles were synthesized from an aqueous extract of macrofungus (mushroom), namely Phellinus adamantinus, in a dark room using 20 µL of silver nitrate. Biosynthesized silver nanoparticles were confirmed by analyzing them using a UV-Vis (ultraviolet-visible) spectrophotometer. The synthesized silver nanoparticles were optimized at different pH and temperatures with various dosages of AgNO3 (silver nitrate) and fungal extracts. The synthesized AgNPs (silver nanoparticles) were characterized using TEM (transmission electron microscopy) and EDX (energy-dispersive X-ray) analyses, which confirmed the presence of silver nanoparticles. The size of the nanosilver particles was found to be 50 nm with higher stability. The mycosynthesized AgNPs showed effective antibacterial activity against strains of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (E. coli and Pseudomonas aeruginosa) bacteria. The minimum inhibitory concentration (MIC) was found to be 3.125 μg/mL by MIC assay. The MTT assay (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl-2H-tetrazolium bromide) was performed to study cytotoxicity, and reduced cell viability was recorded at 100 μg/mL. Silver-Polygalacturonic acid-Polyvinyl alcohol ((Ag-PGA)-PVA) nanofiber was prepared using the electrospinning method. The in vitro wound scratch assay was demonstrated to study the wound-healing efficacy of the prepared nanofiber. The wound-healing efficacy of the AgNP-incorporated nanofiber was found to be 20% after 24 h. This study will lay a platform to establish a unique route to the development of a novel nanobiomaterial and its application in antibacterial and wound-healing therapy.

30 July 2021 in Processes
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GVGayathri Vijayakumar
Gayathri Vijayakumar
HKHindhuja Kesavan
Hindhuja Kesavan
AKAnisha Kannan
Anisha Kannan
DADhanalakshmi Arulanandam
Dhanalakshmi Arulanandam
JKJeong Hee Kim
Jeong Hee Kim
SRSENTHIL KUMARAN RANGARAJULU
SENTHIL KUMARAN RANGARAJULU
To prevent microbial growth, chemical solvents are typically utilized. However, chemical solvents are hazardous to human health with low antimicrobial effects. Metallic-element (such as copper, silver, and gold) nanoparticles have many applications in biotechnology and biomedicine. Copper nanoparticles (CuNPs) are efficient owing to their antimicrobial, anti-inflammatory, and anti-proliferative properties. The objective of this study was to perform biogenic synthesis of copper nanoparticles using three different spices (star anise, seed of Illicium verum; nutmeg, seed of Myristica fragrans; and mace, membrane covering the seed of Myristica fragrans) and determine their antibacterial properties. CuNPs of spices were prepared by dissolving copper sulfate in the respective plant extract. They were then characterized by UV-Vis spectroscopy, FTIR, GC-MS, EDAX, and SEM analysis. Results of UV-Vis spectroscopy showed the maximum absorbance peak at 350 nm. SEM analysis showed that the sizes of these CuNPs were in the range of 150–200 nm. EDAX analysis confirmed the presence of copper and oxygen and revealed that copper existed in an oxidized form. FTIR spectroscopy showed the presence of different functional groups in these synthesized nanoparticles. GC-MS analysis revealed compounds such as Anethole D-limonene, heptadecanoic acid, 16-methyl-, methyl ester, myristene, methyl eugenol, and methyl stearate, indicating the presence of functional groups. The antibacterial activities of the three extracts from spices were analyzed using growth zone inhibition and TLC-bioautography methods. The results showed that star anise spice extract had the highest antibacterial activity. These results indicate that such CuNPs phyto-formulated with spice extracts having antibacterial properties could be used as potential therapeutics for microbial diseases.

29 November 2020 in Journal of Food Processing and Preservation
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GVGayathri Vijayakumar
Gayathri Vijayakumar
MBMohanKumar BS
MohanKumar BS

28 December 2025 in Processes
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GVGayathri Vijayakumar
Gayathri Vijayakumar
AKAbhiraami Kavirajan
Abhiraami Kavirajan
KNKeerthi Neminla
Keerthi Neminla
SRSENTHIL KUMARAN RANGARAJULU
SENTHIL KUMARAN RANGARAJULU
Biogenic synthesis of gold nanoparticles using plant extracts has been widely explored for biomedical applications due to its eco-friendly and cost-effective nature. In this study, gold nanoparticles were phytoformulated using an ethanolic extract of dwarf copper leaf. Their physicochemical properties, antineoplastic activity against MCF-7 breast cancer cells, and bactericidal efficacy against selected pathogenic microorganisms were systematically evaluated. The phyto-synthesized AuNPs show potential as an antineoplastic agent, significantly dropping the viability of MCF-7 breast cancer cells when administered at higher concentrations. Comprehensive characterization revealed that the phyto-formulated AuNPs were predominantly spherical with sizes ranging from 15–38 nm as observed by TEM, while XRD analysis confirmed their crystalline nature. Furthermore, FT-IR analysis determined the plant extract’s functional groups, which served as both reducing and stabilizing agents during synthesis. Additionally, the phyto-formulated AuNPs showed bactericidal efficacy against several microorganisms, including Bacillus cereus, Salmonella typhimurium, Staphylococcus epidermidis, and Serratia species. Particularly, the phyto-formulated AuNPs were effective against B. cereus and Serratia species. The present results showed that the phyto-formulated AuNPs could be used in biomedical contexts for bactericidal action and medication delivery. By using this cost-effective and eco-friendly nanobiotechnology method, AuNPs can enhance drug delivery and efficacy with lower toxicity effects associated with conventional chemotherapies.

13 March 2026 in Processes
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GVGayathri Vijayakumar
Gayathri Vijayakumar
SBSwetha B
Swetha B
SRSowmiya Raghupathy
Sowmiya Raghupathy
SRSENTHIL KUMARAN RANGARAJULU
SENTHIL KUMARAN RANGARAJULU
Sustainable alternatives to synthetic polymer-based sanitary napkins are essential to reduce the environmental impact and health concerns. This study presents a method for using water hyacinth (Eichhornia crassipes), an invasive aquatic weed, as biomass to produce biodegradable absorbent material for sanitary pads. Water hyacinth fibers were treated with an alkaline solution and incorporated into the absorbent core. Morphological, chemical, structural, functional, microbiological, and biodegradability evaluations were then conducted systematically. Scanning electron microscopy showed that non-cellulosic components were successfully removed, producing a rougher surface topology and enhanced fiber interactions. Fourier-transform infrared spectroscopy confirmed structural changes in cellulose after treatment. Additionally, X-ray diffraction showed that the crystallinity index increased from 53.21% in untreated fibers to 62.56% in treated fibers, indicating improved order and stability. The developed absorbent sanitary pad showed rapid fluid uptake, absorbing 10 mL within three seconds while maintaining a skin-compatible neutral pH of 6.87, as specified in Indian Standard IS 5405:1980. Microbial contamination remained low, with a total bacterial count of 360 CFU/g, no yeast or mold at ≤1 CFU/g, and no presence of Staphylococcus aureus. Soil burial tests showed 70% biodegradability at 40 days and approximately 95% at 60 days, indicating high biodegradability. These findings demonstrate the potential of water hyacinth as an inexpensive and environmentally friendly material for manufacturing hygienic sanitary pads, highlighting the sustainability benefits of valorizing invasive biomass and reducing reliance on synthetic polymers.