JNJohny Neamţu

Johny Neamţu

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Previous Organizations / Institutes

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Johny Neamţu has a total of 134 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Poly(Lactic-Co-Glycolic Acid)-Based Systems in Implantology: Advances in Biomaterial Design, Drug Delivery, and Tissue Regeneration

    by Bogdan Alexandru Popescu, Ionela Belu, Andreea Gabriela Mocanu, Maria Viorica Ciocîlteu, Daniela Calina, Costel Valentin Manda, Johny Neamțu, Oana Elena Nicolaescu, Andreea-Cristina Stoian, Andreea Silvia Pîrvu

    Poly(lactic-co-glycolic acid) (PLGA) is one of the most extensively investigated biodegradable polymers for biomedical applications, owing to its tunable degradation kinetics, established biocompatibility, and regulatory approval. In implantology, PLGA-based systems have emerged as versatile platforms for scaffolds, coatings, and localized drug delivery, aimed at enhancing osseointegration and tissue regeneration. This review provides a focused and up-to-date analysis of PLGA applications in dental and orthopedic implantology, with particular emphasis on advances reported over the past decade. Unlike previous reviews that predominantly address general drug delivery or broad tissue engineering applications, this work establishes a direct correlation between polymer composition (LA:GA ratio), processing strategies, and biological outcomes, including degradation behavior, mechanical performance, and host response. Special attention is given to multifunctional PLGA systems incorporating antibiotics, growth factors, and bioactive nanoparticles, highlighting their role in improving antibacterial efficacy and osteogenesis. Emerging technologies such as nanostructured composites, additive manufacturing, and stimuli-responsive delivery platforms are critically evaluated. Key limitations—including acidic degradation by-products, burst release kinetics, and translational barriers—are discussed in the context of clinical applicability. By integrating physicochemical design with biological performance and recent clinical trends (2024–2025), this review proposes a framework for the rational development of next-generation PLGA-based implant systems.


  • Open Access

    Development and Validation of an SPE–LC–MS Method for the Determination of Epirubicin, Olaparib and Ribociclib in Human Serum

    by Monica Denisa Elena Popescu, Costel-Valentin Manda, Octavian Croitoru, Daniela-Maria Calucică, Johny Neamțu, Andrei Biță, Amelia Maria Găman, Simona-Daniela Neamțu

    Background/Objectives: Epirubicin, Olaparib, and Ribociclib are widely used anticancer agents whose serum concentrations exhibit significant inter-individual variability, supporting the need for reliable and robust analytical methods suitable for pharmacokinetic evaluation and therapeutic exposure assessment. Variations in metabolism, drug–drug interactions, organ function, and treatment regimens may substantially influence systemic exposure, highlighting the importance of accurate quantification in clinical practice. This study describes the development and validation of a solid-phase extraction–liquid chromatography–mass spectrometry (SPE–LC–MS) method for the simultaneous quantification of these drugs in human serum. Methods: Sample preparation was performed using Oasis PRiME HLB® cartridges to ensure efficient clean-up, optimal recovery, and reduced matrix effects. Chromatographic separation was achieved using gradient elution with 0.1% formic acid and acetonitrile on a reversed-phase column, followed by single-quadrupole mass spectrometric (QDa) detection in the selected ion recording mode. The total run time was 13 min, enabling high-throughput analysis. Results: The method demonstrated good linearity (r > 0.997) over the tested concentration ranges, along with adequate selectivity, precision, accuracy, recovery, and stability, fulfilling the ICH M10 guideline validation criteria. No significant carry-over or interference from endogenous compounds was observed. Conclusions: Application to patient samples confirmed reliable performance in real clinical matrices and consistent quantification across different concentration levels. The proposed approach provides a potentially more accessible alternative in laboratories already equipped with LC-MS systems compared to LC-MS/MS platforms and can be applied in pharmacokinetic studies, representing a proof-of-concept for exposure assessment in oncology.


  • Open Access

    Standardization of Romanian Galeopsis tetrahit Leaf Extract in Verbascoside Using a Validated UHPLC–PDA Method

    by Roxana Maria Golu, Ludovic Everard Bejenaru, Andrei Biţă, Cornelia Bejenaru, Adina-Elena Segneanu, Maria Viorica Ciocîlteu, Antonia Blendea, Johny Neamţu, George Dan Mogoşanu

    Galeopsis tetrahit L. (Lamiaceae) is a traditional European medicinal species rich in phenolic compounds, among which verbascoside is a key bioactive marker with strong antioxidant potential. This study reports the standardization of a G. tetrahit leaf extract in verbascoside using a fully validated UHPLC–PDA method developed according to ICH Q2(R2) requirements. Leaves of wild-grown G. tetrahit collected from southwest Romania flora were extracted with 70% ethanol, yielding 17.28% dry extract. Chromatographic identification of verbascoside was confirmed by retention time, UV–PDA spectra, and QDa mass spectrometry (m/z 623.3 [M–H]−). The method showed excellent performance, including high specificity, linearity over 1.875–60 μg/mL (r = 0.999955), low LOD and LOQ (0.2649 and 0.8028 μg/mL, respectively), and robust precision and accuracy. Dry extract contained 345.8 ± 28.3 mg verbascoside per g (34.6%, w/w), corresponding to approximately 59.8 mg/g in dried leaves. Antioxidant assays (DPPH, ABTS, FRAP), TPC and TFC confirmed notable radical scavenging and reducing activity, with pure verbascoside showing markedly stronger effects, supporting its major contribution to the extract’s antioxidant potential. These results demonstrate a reliable analytical approach and establish a verbascoside-based standardization framework for G. tetrahit extracts of documented Romanian origin.


  • Open Access

    Standardization of Romanian Galeopsis tetrahit Leaf Extract in Verbascoside Using a Validated UHPLC–PDA Method

    by Roxana Maria Golu, Ludovic Everard Bejenaru, Andrei Biţă, Cornelia Bejenaru, Adina-Elena Segneanu, Maria Viorica Ciocîlteu, Antonia Blendea, Johny Neamţu, George Dan Mogoşanu

    Galeopsis tetrahit L. (Lamiaceae) is a traditional European medicinal species rich in phenolic compounds, among which verbascoside is a key bioactive marker with strong antioxidant potential. This study reports the standardization of a G. tetrahit leaf extract in verbascoside using a fully validated UHPLC–PDA method developed according to ICH Q2(R2) requirements. Leaves of wild-grown G. tetrahit collected from southwest Romania flora were extracted with 70% ethanol, yielding 17.28% dry extract. Chromatographic identification of verbascoside was confirmed by retention time, UV–PDA spectra, and QDa mass spectrometry (m/z 623.3 [M–H]–). The method showed excellent performance, including high specificity, linearity over 1.875–60 μg/mL (r = 0.999955), low LOD and LOQ (0.2649 and 0.8028 μg/mL, respectively), and robust precision and accuracy. Dry extract contained 345.8 ± 28.3 mg verbascoside per g (34.6%, w/w), corresponding to approximately 59.8 mg/g in dried leaves. Antioxidant assays (DPPH, ABTS, FRAP), TPC and TFC confirmed notable radical scavenging and reducing activity, with pure verbascoside showing markedly stronger effects, supporting its major contribution to the extract’s antioxidant potential. These results demonstrate a reliable analytical approach and establish a verbascoside-based standardization framework for G. tetrahit extracts of documented Romanian origin.

  • Open Access

    Boron Bioavailability Revisited: From Plasma-Accessible Species to Microbiota-Accessible Complexes—Implications for Nutritional Essentiality

    by Andrei Biţă, Ion Romulus Scorei, Marvin A. Soriano-Ursúa, Cătălina Gabriela Pisoschi, Cristina Elena Biţă, Laura Dincă, Simona Ştefănescu, Maria-Victoria Racu, Iurie Pinzaru, Cristina Florescu, et al.

    Boron (B) remains one of the least understood trace elements in human nutrition. Traditionally regarded as non-essential, its biological role has been reevaluated in light of emerging microbiome research. We provide a narrative synthesis of mechanistic, preclinical, and clinical studies to assess whether the colonic actions of B meet accepted criteria for nutritional essentiality. This review revisits B bioavailability through a dual-pathway framework distinguishing plasma-accessible boron (PAB)—small, fully absorbable species with transient systemic effects—from microbiota-accessible boron complexes (MABCs)—indigestible conjugates that reach the colon intact. Evidence indicates that PAB exerts short-term metabolic modulation, whereas MABCs act as prebiotic cofactors that stabilize microbial quorum sensing (autoinducer-2–borate; AI-2B), reinforce the colonic mucus barrier through borate–diol crosslinking, and support host–microbiota symbiosis. Deficiency or low intake of MABCs leads to dysbiosis, barrier fragility, and low-grade inflammation along gut–organ axes—effects reversible by MABC-rich diets. Analytical and clinical tools are proposed to discriminate between PAB and MABC pathways, including fecal B/speciation, AI-2B assays, and mucus-penetration markers. Recognizing B’s essentiality as a microbiota-dependent nutrient reframes its nutritional assessment, guiding future dietary guidelines and prebiotic design toward the microbiome–mucus interface.


  • Open Access

    Microbiota-Accessible Borates as Novel and Emerging Prebiotics for Healthy Longevity: Current Research Trends and Perspectives

    by Andrei Biţă, Ion Romulus Scorei, Marvin A. Soriano-Ursúa, George Dan Mogoşanu, Ionela Belu, Maria Viorica Ciocîlteu, Cristina Elena Biţă, Gabriela Rău, Cătălina Gabriela Pisoschi, Maria-Victoria Racu, et al.

    Precision nutrition-targeted gut microbiota (GM) may have therapeutic potential not only for age-related diseases but also for slowing the aging process and promoting longer healthspan. Recent studies have shown that restoring a healthy symbiosis of GM by counteracting dysbiosis (DYS) through precise nutritional intervention is becoming a major target for extending healthspan. Microbiota-accessible borate (MAB) complexes, such as boron (B)–pectins (rhamnogalacturonan–borate) and borate–phenolic esters (diester chlorogenoborate), have a significant impact on healthy host–microbiota symbiosis (HMS). The mechanism of action of MABs involves the biosynthesis of the autoinducer-2–borate (AI-2B) signaling molecule, B fortification of the mucus gel layer by the MABs diet, inhibition of pathogenic microbes, and reversal of GM DYS, strengthening the gut barrier structure, enhancing immunity, and promoting overall host health. In fact, the lack of MAB complexes in the human diet causes reduced levels of AI-2B in GM, inhibiting the Firmicutes phylum (the main butyrate-producing bacteria), with important effects on healthy HMS. It can now be argued that there is a relationship between MAB-rich intake, healthy HMS, host metabolic health, and longevity. This could influence the deployment of natural prebiotic B-based nutraceuticals targeting the colon in the future. Our review is based on the discovery that MAB diet is absolutely necessary for healthy HMS in humans, by reversing DYS and restoring eubiosis for longer healthspan.


  • Open Access

    Phenolic Acid Investigation and In Vitro Antioxidant and Antiacetylcholinesterase Potentials of Galeopsis spp. (Lamiaceae) from Romanian Flora

    by Roxana Maria Golu, Cornelia Bejenaru, Ludovic Everard Bejenaru, Adina-Elena Segneanu, Andrei Biţă, Antonia Radu, Adriana Cosmina Tîrnă, Maria Viorica Ciocîlteu, George Dan Mogoşanu, Johny Neamţu, et al.

    Background/Objectives Galeopsis spp. (Lamiaceae) are widely distributed across extensive areas in Romania, being used mainly for their sedative, neuroprotective, antioxidant, anti-inflammatory, expectorant, astringent, and diuretic properties. The paper reports for the first time the investigation of the total phenolic content (TPC), total flavonoid content (TFC), and phenolic acid profile in the roots, aerial parts, and leaves from three wild-grown Galeopsis spp. (G. bifida Boenn., G. speciosa Mill., and G. tetrahit L.), along with their antioxidant and acetylcholinesterase (AChE) inhibitory potentials. Methods: The ultra-high-performance liquid chromatography/ultraviolet/mass spectrometry (HPLC/UV/MS) method was used for the identification and quantification of key phenolic acids. The spectrophotometric method was applied for the determination of TPC, TFC, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and also the ferric-reducing antioxidant power (FRAP). High-performance thin-layer chromatography (HPTLC) was employed for the assessment of in situ antioxidant (DPPH assay) and AChE inhibitory potentials. Results: Galeopsis spp. exhibit significant polyphenol accumulation. Chlorogenic acid was the most abundant compound, with the highest levels detected in G. tetrahit leaves (22,347.907 ± 1117.395 μg/g), followed by G. tetrahit aerial parts (11,678.509 ± 583.925 μg/g) and G. speciosa leaves (8712.628 ± 435.631 μg/g). G. tetrahit leaves had the highest DDPH radical scavenging activity, with a half-maximal inhibitory concentration (IC50) of 0.458 ± 0.03 mg/mL, demonstrating a markedly stronger antioxidant effect. Leaves consistently showed the strongest DPPH activity across all species, with G. speciosa leaves also displaying a low IC50 value of 0.789 ± 0.03 mg/mL, comparable to G. tetrahit. Aerial parts exhibited an intermediate effect, with G. bifida aerial parts showing an IC50 of 8.102 ± 0.49 mg/mL, while G. tetrahit aerial parts demonstrated stronger activity at 1.511 ± 0.11 mg/mL. AChE inhibition activity increased progressively from the roots to aerial parts to leaves, with leaves consistently exhibiting the strongest inhibitory effects across all Galeopsis spp. G. tetrahit leaves had the strongest inhibition, with an IC50 of 4.002 ± 0.32 mg/mL, followed by G. speciosa leaves (6.92 ± 0.14 mg/mL) and G. bifida leaves (6.97 ± 0.68 mg/mL). Conclusions: Our study provides a comprehensive analysis of the phenolic acid content, in vitro antioxidant activity, and neuroprotective potential of three Galeopsis spp. (G. bifida, G. speciosa, and G. tetrahit) from the southwestern Romanian flora.


  • Open Access

    Phenolic Acids Investigation and In Vitro Antioxidant and Antiacetylcholinesterase Potential of Galeopsis spp. (Lamiaceae) from Romania Flora

    by Roxana Maria Golu, Cornelia Bejenaru, Ludovic Everard Bejenaru, Adina-Elena Segneanu, Andrei Biţă, Antonia Radu, Adriana Cosmina Tîrnă, Maria Viorica Ciocîlteu, George Dan Mogoşanu, Johny Neamţu, et al.

    Background/Objectives: Galeopsis spp. (Lamiaceae) are widely distributed across extensive areas in Romania, being used mainly for their sedative, neuroprotective, antioxidant, anti-inflammatory, expectorant, astringent and diuretic properties. The paper reports, for the first time, the investigation of total phenolic content (TPC), total flavonoid content (TFC) and phenolic acids profile in roots, aerial parts and leaves from three wild-grown Galeopsis spp. (G. bifida Boenn., G. speciosa Mill. and G. tetrahit L.), along with their . Methods: Ultra-high-performance liquid chromatography/ultraviolet/mass spectrometry (HPLC/UV/MS) method was used for the identification and quantification of key phenolic acids. The spectrophotometric method was applied for the determination of TPC, TFC, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, and also ferric-reducing antioxidant power (FRAP). High-performance thin-layer chromatography (HPTLC) was employed for the assessment of in situ antioxidant (DPPH assay) and AChE inhibitory potential. Results: Galeopsis spp. significantly contributes to polyphenol accumulation. Chlorogenic acid was the most abundant compound, with the highest levels detected in G. tetrahit leaves, followed by G. tetrahit aerial parts and G. speciosa leaves. G. tetrahit consistently showed the highest antioxidant potential, followed by G. speciosa, while G. bifida exhibited the weakest activity. AChE inhibition activity increases progressively from roots to aerial parts to leaves, with leaves consistently exhibiting the strongest inhibitory effects across all Galeopsis spp. Conclusions: Our study provides novel and valuable insights into the bioactivity of Galeopsis spp., a group of plants that has been largely overlooked in phytochemical and pharmacological research.


  • Open Access

    PRELIMINARY HPTLC INVESTIGATION OF TWO GALEOPSIS SPP. (LAMIACEAE) FROM SOUTHWEST ROMANIA FLORA

    by Roxana Maria Golu, Ludovic Everard Bejenaru, Andrei Biţă, Cornelia Bejenaru, Antonia Radu, George Dan Mogoşanu, Johny Neamţu

    The paper highlights the phenolic acids content of roots, aerial parts and leaves of two Galeopsis spp. (Lamiaceae) from the southwest Romania (Oltenia Region) flora, using high-performance thin-layer chromatography (HPTLC) coupled with photodensitometry. Chlorogenic acid (CGA) was identified and quantified in all 70% ethanolic extracts of Galeopsis spp. The highest CGA amount was determined in G. speciosa leaves (9.192 mg/g), followed by G. bifida leaves (9.017 mg/g), G. speciosa roots (8.283 mg/g), G. speciosa aerial parts (7.317 mg/g), G. bifida aerial parts (3.392 mg/g), and G. bifida roots (1.825 mg/g). Our research used HPTLC for the assessment of phenolic acid content, emphasizing the pharmacological potential of Galeopsis spp., mainly the antioxidant properties, which may contribute to their traditional applications in treating respiratory and inflammatory disorders.

  • Open Access

    Simultaneous Determination of Epirubicin, Olaparib and Ribociclib in Human Serum by SPE-LC-MS

    by Octavian Croitoru, Monica Denisa Elena Popescu, Costel-Valentin Manda, Daniela Maria Calucică, Johny Neamțu, Andrei Biță, Amelia Maria Găman, Simona-Daniela Neamțu

    Epirubicin, olaparib and ribociclib are three anti-tumoral molecules currently used in cancer therapy. Since serum levels of these drugs reveal a large inter-individual variability, validation of a fast, simple and reliable analytical method for quantitative determination of these molecules in human serum, with Therapeutic Drug Monitoring (TDM) purposes would be necessary. Papers in literature describe separation, identification and quantitation of the drugs in pharmaceutical formulas and biological matrices. The large majority of these approaches use protein precipitation for sample pre-treatment, followed by LC separation and tandem-mass-spectrometry (MS/MS) detection. We propose an alternative method using Solid Phase Extraction (SPE) with Oasis PRiME HLB® cartridges followed by high-performance liquid chromatography (HPLC) using a C18 (4.6 × 50 mm) column. A gradient mobile phase with 0.1% formic acid/acetonitrile was utilized. MS detection in single ion recording (SIR) mode was employed. A 13-minutes run-time analysis, including column re-equilibration was assessed. Data for all molecules were validated according to ICH Guidelines. Calibration curves for all analytes were linear with correlation coefficient larger than 0.997. Values for precision were less than 6%. The method was applied on serum samples from patients up-taking the drugs, proving its suitability in TDM assisted adjustment of doses in therapy.