Daniela Istrati

Dr. Daniela Istrati

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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21 May 2024 in Nanomaterials
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Adelina-Gabriela NiculescuAdelina-Gabriela Niculescu
Adelina-Gabriela Niculescu
O(Oana Maria Munteanu (Mihaiescu)
Oana Maria Munteanu (Mihaiescu)
ABAda Birca
Ada Birca
AMAlina Moroșan
Alina Moroșan
BPBogdan Purcăreanu
Bogdan Purcăreanu
Alexandru Mihai GrumezescuAlexandru Mihai Grumezescu
Alexandru Mihai Grumezescu
This study’s main objective was to fabricate an innovative three-dimensional microfluidic platform suitable for well-controlled chemical syntheses required for producing fine-tuned nanostructured materials. This work proposes using vortex mixing principles confined within a 3D multilayered microreactor to synthesize magnetic core-shell nanoparticles with tailored dimensions and polydispersity. The newly designed microfluidic platform allowed the simultaneous obtainment of Fe3O4 cores and their functionalization with a salicylic acid shell in a short reaction time and under a high flow rate. Synthesis optimization was also performed, employing the variation in the reagents ratio to highlight the concentration domains in which magnetite is mainly produced, the formation of nanoparticles with different diameters and low polydispersity, and the stability of colloidal dispersions in water. The obtained materials were further characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM), with the experimental results confirming the production of salicylic acid-functionalized iron oxide (Fe3O4-SA) nanoparticles adapted for different further applications.

24 November 2021 in Nanomaterials
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DIDaniela Istrati
Daniela Istrati
AMAlina Moroșan
Alina Moroșan
Raluca StanRaluca Stan
Raluca Stan
Bogdan Stefan VasileBogdan Stefan Vasile
Bogdan Stefan Vasile
VGVasilievici Gabriel
Vasilievici Gabriel
Dan Eduard MihaiescuDan Eduard Mihaiescu
Dan Eduard Mihaiescu
This work describes a new synthesis method for core–shell magnetite nanoparticles with a secondary silica shell, functionalized with a linker system (Fe3O4-PABA-SiO2-linker) using a microwave-assisted heating technique. The functionalized solid nanomaterial was used for the nanophase synthesis of peptides (Fmoc route) as a solid support. The co-precipitation method was selected to obtain magnetite nanoparticles and sol–gel technique for silica coating using a microwave-assisted (MW) procedure. The magnetic properties of the nanoparticle core offer the advantage of a quick and easy alternative for the magnetic separation of the product from the reaction mixture, facilitating all the intermediary washing and separation operations. The intermediate and final materials were analyzed by advanced characterization methods. The effectiveness of the nanophase peptide synthesis using this nanostructured material as solid support was demonstrated for a short peptide sequence.

11 June 2024 in Gels
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Adelina-Gabriela NiculescuAdelina-Gabriela Niculescu
Adelina-Gabriela Niculescu
BMBogdan Mihaiescu
Bogdan Mihaiescu
ABAda Birca
Ada Birca
AMAlina Moroșan
Alina Moroșan
O(Oana Maria Munteanu (Mihaiescu)
Oana Maria Munteanu (Mihaiescu)
Alexandru Mihai GrumezescuAlexandru Mihai Grumezescu
Alexandru Mihai Grumezescu
Aerogels have emerged as appealing materials for various applications due to their unique features, such as low density, high porosity, high surface area, and low thermal conductivity. Aiming to bring the advantages of these materials to the environmental field, this study focuses on synthesizing magnetic silica aerogel-based films suitable for water decontamination. In this respect, a novel microfluidic platform was created to obtain core-shell iron oxide nanoparticles that were further incorporated into gel-forming precursor solutions. Afterward, dip-coating deposition was utilized to create thin layers of silica-based gels, which were further processed by 15-hour gelation time, solvent transfer, and further CO2 desiccation. A series of physicochemical analyses (XRD, HR-MS FT-ICR, FT-IR, TEM, SEM, and EDS) were performed to characterize the final films and intermediate products. The proposed advanced imaging experimental model for film homogeneity and adsorption characteristics confirmed uniform aerogel film deposition, nanostructured surface, and ability to remove pesticides from contaminated water samples. Based on thorough investigations, it was concluded that the fabricated magnetic aerogel-based thin films are promising candidates for water decontamination and novel solid-phase extraction sample preparation.

3 November 2022 in Gels
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Dan Eduard MihaiescuDan Eduard Mihaiescu
Dan Eduard Mihaiescu
DIDaniela Istrati
Daniela Istrati
AMAlina Moroșan
Alina Moroșan
Maria StancaMaria Stanca
Maria Stanca
BPBogdan Purcăreanu
Bogdan Purcăreanu
RTRoxana Trușcă
Roxana Trușcă
As a third-generation β-lactam antibiotic, cefotaxime shows a broad-spectrum with Gram-positive and Gram-negative bacteria activity and is included in WHO’s essential drug list. In order to obtain new materials with sustained release properties, the present research focuses on the study of cefotaxime absorption and desorption from different functionalized mesoporous silica supports. The MCM-41-type nanostructured mesoporous silica support was synthesized by sol–gel technique using a tetraethyl orthosilicate (TEOS) route and cetyltrimethylammonium bromide (CTAB) as a surfactant, at room temperature and normal pressure. The obtained mesoporous material (MCM-41 class) was characterized through nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), N2 absorption–desorption (BET) and Fourier transform infrared spectroscopy (FT-IR), proving a good micro-structured homogeneity (SEM images), a high surface area (BET, 1029 m2/g) correlated with high silanolic activity (Q3/Q4 peak ratio from 29Si MAS-NMR), and an expected uniform hexagonal structure (2–3 nm, HRTEM). In order to non-destructively link the antibiotic compound on the solid phase, MCM-41 was further functionalized in two steps: with aminopropyl trimethoxysilane (APTMS) and glutaraldehyde (GA). Three cefotaxime-loaded materials were comparatively studied for low release capacity: the reference material with adsorbed cefotaxime on MCM-41, MCM-41/APS (aminopropyl silyl surface functionalization) adsorbed cefotaxime material, and APTMS–GA bounded MCM-41—cefotaxime material. The slow-release profiles were obtained by using an on-flow modified HPLC system. A significant improved release capacity was identified in the case of MCM-41/APS/GA—cefotaxime due to the covalent surface grafting of the biological active compound, recommending this class of materials as an effective carrier of bioactive compounds in wound dressing, anti-biofilm coatings, advanced drugs, and other related applications.

2 April 2023 in Pharmaceutics
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RȚRobert Andrei Țincu
Robert Andrei Țincu
MMMirela Mihaila
Mirela Mihaila
MBMarinela Bostan
Marinela Bostan
FTFlorina Teodorescu
Florina Teodorescu
DIDaniela Istrati
Daniela Istrati
ILIoana Lacatusu
Ioana Lacatusu
A novel nanoscale approach was developed for the improved cellular internalization of hybrid bovine serum albumin–lipid nanocarriers loaded with piperine (NLC-Pip–BSA) in different tumor cells. The effect of the BSA-targeted–NLC-Pip and untargeted-NLC-Pip on the viability, proliferation, and levels of cell-cycle damage and apoptosis in the colon (LoVo), ovarian (SKOV3) and breast (MCF7) adenocarcinoma cell lines was comparatively discussed. NLCs were characterized concerning particle size, morphology, zeta potential, phytochemical encapsulation efficiency, ATR-FTIR, and fluorescence spectroscopy. The results showed that NLC-Pip–BSA showed a mean size below 140 nm, a zeta potential of −60 mV, and an entrapment efficiency of 81.94% for NLC-Pip and 80.45% for NLC-Pip–BSA. Fluorescence spectroscopy confirmed the coating of the NLC with the albumin. By MTS and RTCA assays, NLC-Pip–BSA showed a more pronounced response against the LoVo colon cell line and MCF-7 breast tumor cell lines than against the ovarian SKOV-3 cell line. Flow cytometry assay demonstrated that the targeted NLC-Pip had more cytotoxicity and improved apoptosis than the untargeted ones in MCF-7 tumor cells (p < 0.05). NLC-Pip caused a significant increase in MCF-7 breast tumor cell apoptosis of ~8X, while NLC-Pip–BSA has shown an 11-fold increase in apoptosis.

Verified
Journal Article
Open access
PDF file
RȚRobert Andrei Țincu
Robert Andrei Țincu
MMMirela Mihaila
Mirela Mihaila
MBMarinela Bostan
Marinela Bostan
DIDaniela Istrati
Daniela Istrati
Nicoleta BadeaNicoleta Badea
Nicoleta Badea
ILIoana Lacatusu
Ioana Lacatusu
The current research attempted to address the suitability of bioactive Sambucus nigra extract entrapped in albumin-decorated nanostructured lipid carriers (NLCs) as a promising “adjuvant” in improving tumour penetration for multiple antitumour therapy. The new hybrid albumin-decorated NLCs were characterised based on, e.g., the particle size, zeta electrokinetic potential, SambucusN entrapment efficiency, and fluorescence spectroscopy and tested for different formulation parameters. The antioxidant activity of NLC-SambucusN was significantly enhanced by a bovine serum albumin (BSA) polymer coating. According to the real-time cell analysis (RTCA) results, NLC-I–SambucusN–BSA behaved similarly to the chemotherapeutic drug, cisplatin, with cell viability for LoVo tumour cells of 21.81 ± 1.18%. The new albumin–NLC–SambucusN arrested cancer cells in G1 and G2 cycles and intensified the apoptosis process in both early and late phases. An advanced induction, over 50% apoptosis in LoVo colon cells, was registered for 50 μg/mL of NLC-II-SambucusN-BSA, a fourfold increase compared to that of untreated cells. RTCA and flow cytometry results showed that concentrations of the hybrid NLC–SambucusN up to 50 μg/mL do not affect the proliferation of normal HUVEC cells. This approach provides insightful information regarding the involvement of phytochemicals in future therapeutic strategies. Albumin-decorated NLCs can be considered a noteworthy strategy to be connected to antitumour therapeutic protocols.