Sreenivasa Nayaka

Dr. Sreenivasa Nayaka

Assistant Professor
+1
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

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30 January 2022 in Nanomaterials
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Journal Article
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Muthuraj RudrappaMuthuraj Rudrappa
Muthuraj Rudrappa
HRHassan Rudayni
Hassan Rudayni
RARasha Assirii
Rasha Assirii
ABAsmatanzeem Bepari
Asmatanzeem Bepari
Dhanyakumara Shivapoojar BasavarajappaDhanyakumara Shivapoojar Basavarajappa
Dhanyakumara Shivapoojar Basavarajappa
Sreenivasa NayakaSreenivasa Nayaka
Sreenivasa Nayaka
Plumeria alba (P. alba) is a small laticiferous tree with promising medicinal properties. Green synthesis of nanoparticles is eco-friendly, cost-effective, and non-hazardous compared to chemical and physical synthesis methods. Current research aiming to synthesize silver nanoparticles (AgNPs) from the leaf extract of P. alba (P- AgNPs) has described its physiochemical and pharmacological properties in recognition of its therapeutic potential as an anticancer and antimicrobial agent. These biogenic synthesized P-AgNPs were physiochemically characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM), atomic force microscopy (AFM), X-ray diffractometry (XRD), and zeta potential analysis. Antimicrobial activity was investigated against Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Enterococcus faecalis, Bacillus subtilis, Streptococcus pneumoniae, Candida albicans, and Candida glabrata. Anticancer activity against glioblastoma U118 MG cancer lines was investigated using an MTT assay, and apoptosis activity was determined by flow cytometry. UV–visible spectroscopic analysis portrayed surface plasmon resonance at 403 nm of synthesized P-AgNPs, and FTIR suggested the presence of amines, alkanes, and phenol molecules that could be involved in reduction and capping processes during AgNPs formation. Synthesized particles were spherical in shape and poly-dispersed with an average particle size of 26.43 nm and a poly-dispersity index (PDI) of 0.25 with a zeta potential value of −24.6 mV, ensuring their stability. The lattice plane values confirm the crystalline nature as identified by XRD. These P-AgNPs exhibited potential antimicrobial activity against selected human pathogenic microbes. Additionally, the in vitro MTT assay results showed its effective anticancer activity against the glioma U118 MG cancer cell line with an IC50 value of 9.77 µg/mL AgNPs by initiating apoptosis as identified by a staining study with flow cytometric Annexin V–Fluorescein Isothiocyanate (FITC) and Propidium Iodide (PI). Thus, P. alba AgNPs can be recommended for further pharmacological and other biological research. To conclude, the current investigation developed an eco-friendly AgNPs synthesis using P. alba leaf extract with potential cytotoxic and antibacterial capacity, which can therefore be recommended as a new strategy to treat different human diseases.

16 December 2022 in Materials
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Shashiraj K NShashiraj K N
Shashiraj K N
SNShaik Kalimulla Niazi
Shaik Kalimulla Niazi
ABAsmatanzeem Bepari
Asmatanzeem Bepari
RARasha Assirii
Rasha Assirii
Sreenivasa NayakaSreenivasa Nayaka
Sreenivasa Nayaka
Biosynthesis of silver nanoparticles (AgNPs) using the green matrix is an emerging trend and is considered green nanotechnology because it involves a simple, low-cost, and environmentally friendly process. The present research aimed to synthesize silver nanoparticles from a Leonotis nepetifolia (L.) R.Br. flower bud aqueous extract, characterize these nanoparticles, and perform in vitro determination of their biological applications. UV-Vis spectra were used to study the characterization of biosynthesized L. nepetifolia-flower-bud-mediated AgNPs (LnFb-AgNPs); an SPR absorption maximum at 418 nm confirmed the formation of LnFb-AgNPs. The presumed phytoconstituents subjected to reduction in the silver ions were revealed by FTIR analysis. XRD, TEM, EDS, TGA, and zeta potential with DLS analysis revealed the crystalline nature, particle size, elemental details, surface charge, thermal stability, and spherical shape, with an average size of 24.50 nm. In addition, the LnFb-AgNPs were also tested for antimicrobial activity and exhibited a moderate zone of inhibition against the selected pathogens. Concentration-dependent antioxidant activity was observed in the DPPH assay. Further, the cytotoxicity increased proportionate to the increasing concentration of the biosynthesized LnFb-AgNPs with a maximum effect at 200 μg/mL by showing the inhibition cell viability percentages and an IC50 of 35.84 μg/mL. Subsequently, the apoptotic/necrotic potential was determined using Annexin V/Propidium Iodide staining by the flow cytometry method. Significant early and late apoptosis cell populations were observed in response to the pancreatic ductal adenocarcinoma (PANC-1) cell line, as demonstrated by the obtained results. In conclusion, the study’s findings suggest that the LnFb-AgNPs could serve as remedial agents in a wide range of biomedical applications.

10 July 2023 in Bioengineering
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Shashiraj K NShashiraj K N
Shashiraj K N
AHAnil Hugar
Anil Hugar
SRSuresh Kumar Raju
Suresh Kumar Raju
Muthuraj RudrappaMuthuraj Rudrappa
Muthuraj Rudrappa
MBMeghashyama Bhat
Meghashyama Bhat
Sreenivasa NayakaSreenivasa Nayaka
Sreenivasa Nayaka
Biosynthesized nano-composites, such as silver nanoparticles (AgNPs), can be engineered to function as smart nano-biomedicine platforms for the detection and management of diverse ailments, such as infectious diseases and cancer. This study determined the eco-friendly fabrication of silver nanoparticles using Lagerstroemia speciosa (L.) Pers. flower buds and their efficacy against antimicrobial and anticancer activities. The UV-Visible spectrum was found at 413 nm showing a typical resonance spectrum for L. speciosa flower bud extract-assisted silver nanoparticles (Ls-AgNPs). Fourier transform infrared analysis revealed the presence of amines, halides, and halogen compounds, which were involved in the reduction and capping agent of AgNP formation. X-ray diffraction analysis revealed the face-centered cubic crystals of NPs. Energy dispersive X-ray verified the weight of 39.80% of silver (Ag), TEM analysis revealed the particles were spherical with a 10.27 to 62.5 nm range, and dynamic light scattering recorded the average particle size around 58.5 nm. Zeta potential showed a significant value at −39.4 mV, and finally, thermo-gravimetric analysis reported higher thermal stability of Ls-AgNPs. Further, the obtained Ls-AgNPs displayed good antimicrobial activity against clinical pathogens. In addition, a dose-dependent decrease in the anticancer activity by MTT assay on the osteosarcoma (MG-63) cell line showed a decrease in the cell viability with increasing in the concentration of Ls-AgNPs with an IC50 value of 37.57 µg/mL. Subsequently, an apoptotic/necrosis study was conducted with the help of Annexin-V/PI assay, and the results indicated a significant rise in early and late apoptosis cell populations. Therefore, green synthesized Ls-AgNPs were found to have potent antimicrobial and anticancer properties making them fascinating choices for future bio-medical implementations.

13 March 2023 in Antibiotics
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Muthuraj RudrappaMuthuraj Rudrappa
Muthuraj Rudrappa
SRSuresh Kumar Raju
Suresh Kumar Raju
Shashiraj K NShashiraj K N
Shashiraj K N
Halaswamy H MHalaswamy H M
Halaswamy H M
PGPooja Vidyasagar Gunagambhire
Pooja Vidyasagar Gunagambhire
Sreenivasa NayakaSreenivasa Nayaka
Sreenivasa Nayaka
Currently, the exploration of fungal organisms for novel metabolite production and its pharmacological applications is much appreciated in the biomedical field. In the present study, the fungal strains were isolated from soil of unexplored Yellapura regions. The potent isolate NP5 was selected based on preliminary screening and identified as Penicillium brasilianum NP5 through morphological, microscopic, and molecular characterizations. Synthesis of silver nanoparticles from P. brasilianum was confirmed by the color change of the reaction mixture and UV-visible surface plasmon resonance (SPR) spectra of 420 nm. Fourier transform infrared (FTIR) analysis revealed the functional groups involved in synthesis. Atomic force microscopy (AFM) and transmission electron microscope (TEM) analysis showed aggregation of the NPs, with sizes ranged from 10 to 60 nm, an average particle size of 25.32 nm, and a polydispersity index (PDI) of 0.40. The crystalline nature and silver as the major element in NP5-AgNPs was confirmed by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The negative value −15.3 mV in Zeta potential exhibited good stability, and thermostability was recorded by thermogravimetric analysis (TGA). NP5-AgNPs showed good antimicrobial activity on selected human pathogens in a concentration-dependent manner. The MTT assay showed concentration-dependent anticancer activity with an IC50 of 41.93 µg/mL on the MDA-MB-231 cell line. Further, apoptotic study was carried out by flow cytometry to observe the rate of apoptosis. The calculated sun protection factor (SPF) value confirms good photoprotection capacity. From the results obtained, NP5-AgNPs can be used in the pharmaceutical field after successful in vitro clinical studies.

16 March 2023 in Processes
Verified
Journal Article
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Shashiraj K NShashiraj K N
Shashiraj K N
Sreenivasa NayakaSreenivasa Nayaka
Sreenivasa Nayaka
SRSuresh Kumar Raju
Suresh Kumar Raju
GKGireesh Babu K
Gireesh Babu K
Dhanyakumara Shivapoojar BasavarajappaDhanyakumara Shivapoojar Basavarajappa
Dhanyakumara Shivapoojar Basavarajappa
KPKarthikeyan Perumal
Karthikeyan Perumal
Over past decades, the green method of synthesizing metal nanoparticles has acquired more attentiveness by scientific consensus because of its industrial and biomedical applications. This study focuses on the anti-proliferative effectiveness of AgNPs synthesized from Rotheca serrata (L.) Steane & Mabb. flower bud extract against the PANC-1 cell line in vitro. Various analytical instruments were utilized to visualize the formation of RsFb-AgNPs, such as UV-Vis spectroscopy, FT-IR, SEM, EDS, TEM, XRD, Zeta potential, and DLS analysis. The biosynthesis of RsFb-AgNPs was observed by a change in color and UV-Vis spectroscopy (415 nm). The FT-IR spectra exhibited the existence of many functional groups. XRD confirmed the crystallinity of the AgNPs. Morphology and elemental mapping were assessed by SEM and EDS analysis. The TEM micrograph revealed spherical-shaped particles with sizes ranging from 12 to 40 nm. Zeta potential and DLS analysis were used to measure surface charge and particle size. Biological properties, including the antioxidant, antimicrobial, and anticancer properties of synthesized RsFb-AgNPs, exhibited dose-dependent activities. In DPPH assay, synthesized RsFb-AgNPs inhibited the scavenging of free radicals in a dose-dependent manner. In addition, the resultant RsFb-AgNPs displayed moderate antimicrobial activity against tested pathogens. Further, the anti-proliferative efficacy of biosynthesized RsFb-AgNPs was determined against the PANC-1 cell line using the MTT assay. The results revealed a dose-dependent decrease in viability of cancer cells with an IC50 value of 36.01 µg/mL. Flow cytometry was then used to confirm the apoptotic effects by double staining with annexin V/PI. In response to the pancreatic ductal adenocarinoma cell line, the results showed notable early and late apoptosis cell population percentages. In conclusion, the synthesized RsFb-AgNPs revealed a potential anticancer agent that can induce apoptosis in the PANC-1 cells.

31 July 2023 in Inorganics
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Halaswamy H MHalaswamy H M
Halaswamy H M
Shashiraj K NShashiraj K N
Shashiraj K N
SRSuresh Kumar Raju
Suresh Kumar Raju
Muthuraj RudrappaMuthuraj Rudrappa
Muthuraj Rudrappa
MBMeghashyama Bhat
Meghashyama Bhat
Sreenivasa NayakaSreenivasa Nayaka
Sreenivasa Nayaka
Green nanoparticle (NPs) synthesis is eco-friendly, non-toxic, and the NPs have demonstrated improved biocompatibility for use in healthcare. This study evaluated the biogenic synthesis of AgNPs from the leaves of Cardamine hirsuta L. and their biological properties. The UV-Vis. spectra at 411 nm exhibited a distinct resonance spectrum for C-AgNPs produced from C. hirsuta L. FT-IR analysis exhibited the presence of functional groups of phyto-compounds of C. hirsuta responsible of silver salt reduction and capping agents of C-AgNPs. The microscopic-based study, such as HR-TEM analysis, showed that the particles were uniformly distributed, spherical, and ranged in size from 5.36 to 87.65 nm. EDX analysis confirmed a silver (Ag) content of 36.3% by weight, and XRD analysis exhibited the face-centred cubic (FCC) crystalline nature of C-AgNPs. DLS measured the mean particle size of 76.5 nm. The zeta potential was significant at −27.9 mV, and TGA analysis revealed that C-AgNPs had higher thermal stability. C-AgNPs demonstrated moderate antimicrobial activity against the tested pathogens. In addition, the anti-proliferative activity measured by the MTT assay on the Caco-2 cell line demonstrated decreased cell viability with increasing C-AgNPs dosage, with an IC50 concentration of 49.14 µg/mL. In addition, an Annexin-V/Propidium iodide flow cytometric study was utilized to evaluate the induction of apoptosis in cancer cells. Early and late apoptosis cell populations increased significantly compared to the untreated control. Therefore, green-synthesized C-AgNPs have significant antimicrobial and anti-proliferative abilities, making them intriguing options for future biomedical applications.