Cell and Tissue Journal

Abstract Aim: The aim of this study was to investigate different concentrations of iron oxide nanoparticles in and benzylaminopurine (BAP) bell pepper anther culture on the traits of callus formation, embryogenesis, regeneration and rooting.
Material and methods: The experiment was conducted as a factorial experiment in a completely randomized design under in vitro culture conditions. Flower buds of appropriate size (equal sepal to petal ratio or slightly longer petal) were collected from the greenhouse and acetocarmine solution was used to determine the growth and development stage of microspores. The results showed that the most suitable stage for embryogenesis induction was the late mononuclear stage and the early binuclear stage. In order to sterilize the flower buds, 70% ethanol for 30 seconds and 5% sodium hypochlorite for 20 minutes were used and after each stage they were washed three times with sterile distilled water. Then, the anthers were separated from the flower bud and placed in C medium containing 2 mg/L naphthalene acetic acid (NAA), different concentrations of BAP (0, 0.1, 0.5, and 1 mg/L) and different concentrations of iron oxide nanoparticles (0, 1, 10, and 20 mg/L). After that, the explant cultured in C medium were kept at 35°C in the dark for 8 days in order to apply heat treatment. Then, they were transferred to 25°C in the light for 4 days. After this period, in order to induce embryogenesis, the explants were transferred from C medium to R medium and were subcultured every three weeks until embryos emerged. For further growth and root development, the embryos were transferred to V medium. Results: The results of the analysis of variance of the data showed that using different concentrations of iron oxide nanoparticles had a significant effect on the percentage of embryogenesis, regeneration and rooting of the plant, but did not have a significant effect on the percentage of callus formation. The results of comparing the average data showed that among the different concentrations of iron oxide nanoparticles, the 1 mg/L treatment had the highest percentage of embryogenesis (11.11). Also, the results of comparing the average effect of the nanoparticles on the percentage of regeneration showed that the 1 mg/L treatment had the highest percentage of regeneration (16.66). The results of the interaction effects showed that among the different concentrations of iron oxide nanoparticles and BAP, the highest percentage of embryogenesis was observed in the treatment of 20 mg/L iron oxide nanoparticles and 0 mg/L BAP. Also, the treatment of 20 mg/L iron oxide nanoparticles and 0 mg/L BAP had the highest percentage of regeneration (33.33%). After sufficient growth and root formation, the obtained plants were removed from the glass culture containers and transferred to pots containing sterilized culture medium and watered for adaptation. The tops of the pots were covered with plastic cups, and after three days, the cups were pierced and the plastic was gradually removed from the plant for further adaptation. Ploidy levels were determined by chromosome counting by staining the root tip cells. The results showed that out of the 23 obtained plants, 21 were diploid and had 2n=2x=24 chromosomes and 2 were haploid and had n=x=12 chromosomes. Conclusion: In bell pepper anther culture, different concentrations of iron oxide nanoparticles along with plant growth regulators at different concentrations showed a great effect on embryogenesis, regeneration, and rooting.

Abstract Introduction: Global climate change has significantly increased the frequency and intensity of abiotic stresses, thereby limiting plant growth, development, and overall yield by damaging physiological systems. In response to environmental stressors, plants have evolved various adaptive mechanisms, including the accumulation of compatible solutes such as glycine betaine (GB), which plays a pivotal role in protecting cellular functions under adverse conditions. Also known simply as betaine, this compound is a methylated glycine derivative recognized across plant species for its ability to mitigate the deleterious effects of stressful environments. Its zwitterionic structure; comprising a positively charged trimethylammonium group and a negatively charged carboxyl group, confers high solubility and chemical stability to the molecule.
Owing to its excellent biocompatibility, favorable carbon-to-nitrogen ratio, and high-concentration accumulation, glycine betaine can enhance plant tolerance against a wide spectrum of abiotic stresses. Specifically, GB contributes to photosynthetic recovery and the alleviation of oxidative stress by reducing the accumulation and facilitating the detoxification of reactive oxygen species (ROS). Furthermore, it plays a crucial role in stabilizing membranes and macromolecules, while protecting key components of the photosynthetic apparatus, such as the Rubisco enzyme, Photosystem II (PSII), quaternary enzymes, and complex protein structures. Notably, glycine betaine can accumulate at high concentrations within plant cells without interfering with normal metabolic processes, thereby significantly increasing resilience to various osmotic stresses, extreme temperatures (heat and cold), and oxidative damage. The biosynthesis of glycine betaine occurs through distinct metabolic pathways, including the choline oxidation pathway (prevalent in plants and mammals), the direct glycine methylation pathway (specific to certain bacteria and halophytes), the choline dehydrogenase pathway, and the serine metabolism pathway. Such diversity underscores the vital importance of this osmolyte in mediating responses to environmental stresses. Recently, biotechnological interventions, such as Agrobacterium-mediated transformation, have successfully enhanced stress tolerance in susceptible species by overexpressing key genes, most notably codA, BADH, GSMT, and SDMT. Given the functional diversity of genes involved in the glycine betaine biosynthetic pathway, extensive efforts have been made to develop transgenic plants capable of effective accumulation of this metabolite; however, serious challenges such as unstable and weak transgene expression remain as key obstacles in this path. Factors including promoter type, genomic integration site, and epigenetic factors can influence the final performance. Furthermore, the overexpression of enzymes in the glycine betaine biosynthetic pathway may potentially impair growth by disrupting metabolic stability. Therefore, future research should focus on decoding the molecular networks regulating the biosynthesis, signaling, and transport of glycine betaine, particularly its crosstalk with phytohormones, transcription factors, and the identification of stress-inducible promoters. Additionally, optimizing transformation protocols and synchronizing glycine betaine gene expression with the overall plant metabolism are essential.
Aims: This review examines the biosynthesis, physiological functions, and molecular regulation of glycine betaine (GB). It highlights genetic engineering techniques to boost GB production, offering sustainable strategies for enhancing crop tolerance to environmental stresses.
Conclusion: In-planta biosynthesis of glycine betaine (GB) offers a more sustainable alternative to exogenous application, aligning closely with the principles of green agriculture. By integrating GB synthesis pathways, genetically engineered crops can autonomously boost metabolite production and bolster stress resilience, thereby eliminating the logistical costs of external treatments. Furthermore, a more profound investigation into these biosynthetic pathways will facilitate the identification and cloning of novel target genes, ultimately maximizing GB accumulation and enhancing environmental tolerance.

Abstract Introduction: Cancer is one of the most significant diseases of the present century and ranks as the second leading cause of death worldwide. Its incidence, particularly breast cancer in women, is steadily increasing. This disease arises from uncontrolled cell proliferation and the ability of cancer cells to migrate to healthy tissues, leading to tumor formation and metastasis. The genetic and biological heterogeneity of cancer cells, especially in breast cancer, complicates effective treatment. Conventional therapies such as surgery, chemotherapy, and radiotherapy, although effective in reducing tumor size, are associated with limitations, including damage to healthy cells, drug resistance, and systemic side effects. Therefore, the development of targeted and innovative therapeutic strategies is a priority in cancer research. One promising approach is the use of nanoparticles for targeted drug delivery. Due to their small size, high surface-to-volume ratio, and modifiable surfaces, nanoparticles can efficiently carry drugs and deliver them to target cells. Controlled drug release from nanoparticles reduces uptake by healthy cells and minimizes systemic toxicity. Iron oxide nanoparticles (Fe₃O₄) possess unique magnetic and chemical properties that enable precise guidance to tumor sites and allow real-time monitoring of drug distribution via MRI. Surface modification with biocompatible polymers such as polyethylene glycol (PEG) enhances nanoparticle stability, prolongs systemic circulation, reduces immune clearance, and provides sites for conjugating targeting ligands such as folic acid and glucose. Polylactic acid (PLA), a biodegradable and biocompatible polymer, increases drug-loading capacity and enables sustained and controlled drug release. Combining PLA with PEG and targeting ligands creates multifunctional nanoparticles that are stable, biocompatible, and capable of selectively recognizing cancer cells while minimizing side effects on healthy tissues. Targeting ligands such as folic acid and glucose facilitate selective cellular uptake; folic acid binds to overexpressed receptors on many cancer cells, promoting intracellular drug delivery, while glucose exploits the high metabolic demand of cancer cells, improving the delivery of therapeutic agents or genes.
Aims: Dual-ligand nanoparticles enable multi-pathway targeting, enhancing therapeutic efficacy and potentially overcoming drug resistance. In this study, multifunctional PLA-PEG nanoparticles functionalized with folic acid and glucose and incorporating Fe₃O₄ were developed for targeted drug delivery to triple-negative breast cancer cells (Hs-578T). This system combines magnetic guidance, biocompatibility, controlled drug release, and selective targeting, providing a promising platform for effective and safe breast cancer treatment with reduced side effects compared to conventional therapies.
Materials and Methods: Various chemicals and reagents, including MTT ((3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide)), Ethanol, HCl, NaCl, KH₂PO₄, Chloroform, NH2-PEG-FA, NH2-PEG-Glu, NaOH, and paraformaldehyde were procured from commercial suppliers, while FBS, DMEM, and trypsin-EDTA were used for in vitro studies with Hs-578T breast cancer cells. Multifunctional nanoparticles PPF (PLA-PEG-FA), PPG (PLA-PEG-Glu), and PPGF (PLA-PEG-Glu/FA) were synthesized via the reaction of PLA-acrylate with the respective NH2-PEG derivatives in chloroform under mechanical stirring and mild heating, followed by purification through dialysis and freeze-drying. Methanolic extract of Silybum marianum was prepared by ultrasonication of powdered aerial parts in 80% methanol, followed by centrifugation and filtration. Fe₃O₄ nanoparticles were synthesized via co-precipitation of Fe (III) and Fe (II) salts under nitrogen, followed by gradual addition of Silybum marianum plant extract and NaOH, leading to nanoparticle formation. The particles were collected magnetically, washed, freeze-dried, and stored in dark, dry conditions. Targeted delivery of Curcumin (CUR) was achieved using folic acid and glucose ligands. CUR and Fe₃O₄-OA were incorporated into PPF, PPG, or PPGF matrices using sonication and emulsification in PVA solutions, followed by rotary evaporation to remove chloroform, washing, and filtration to remove unencapsulated drug and large particles. Structural and chemical composition were analyzed using 1H-NMR and FTIR spectroscopy. Morphology was observed via TEM, and average size and zeta potential were measured using dynamic light scattering (DLS). Drug encapsulation efficiency was determined spectrophotometrically by measuring unencapsulated CUR in the supernatant. CUR release kinetics were evaluated in two pH environments: pH=7.4 (normal cells), and pH=4.5 (tumor-like), with periodic sampling and replacement with fresh medium over three days. Cytotoxicity was assessed via the MTT assay, with IC₅₀ values determined after treating Hs-578T cells with varying concentrations of CUR, nanoparticles with CUR, or blank nanoparticles. Apoptosis was analyzed using Annexin V/propidium iodide staining and flow cytometry to distinguish apoptotic and necrotic cells. All experiments were performed in triplicate. Data were analyzed using one-way ANOVA followed by Duncan’s test at a 5% significance level, and normality was verified with the Kolmogorov–Smirnov test. Results are reported as mean ± standard deviation.
Results: Targeted drug delivery has emerged as a promising strategy for treating difficult-to-treat diseases, including cancer, by directing therapeutic agents specifically to diseased tissues while minimizing uptake by normal cells. Biocompatible and biodegradable polymers are essential for efficient delivery systems. PLA, a widely used biodegradable polymer, allows loading and controlled release of hydrophobic drugs like curcumin. However, PLA alone can aggregate in serum due to hydrophobic interactions, leading to immune recognition and clearance. To overcome this, PLA was conjugated with PEG, which enhances nanoparticle circulation time and provides a stealth effect, reducing recognition by the immune system. PEG also improves drug loading and stability, although it is not biodegradable and may accumulate over repeated doses. Magnetic Fe₃O₄ nanoparticles were incorporated to increase targeting efficiency, while folic acid and glucose ligands were used for selective recognition of cancer cells. The synthesized PLA-based nanoparticles demonstrated good biocompatibility with Hs-578T cells, showing no significant cytotoxicity. Drug encapsulation within PLA-PEG nanoparticles allowed controlled and sustained release of curcumin, which was particularly enhanced under acidic conditions mimicking the tumor microenvironment. Notably, nanoparticles containing both folic acid and PEG showed higher drug release compared to those with PEG alone, highlighting the role of folic acid in facilitating curcumin release. This pH-sensitive release profile minimizes drug exposure to normal tissues, potentially reducing side effects. Cytotoxicity assay revealed that curcumin-loaded nanoparticles significantly inhibited Hs-578T cell proliferation compared to free curcumin, with the dual-ligand nanoparticles exhibiting the lowest IC₅₀ values. Flow cytometry analysis demonstrated that these nanoparticles primarily induced apoptosis rather than necrosis, suggesting selective activation of programmed cell death pathways. The enhanced apoptotic effect is likely due to increased cellular uptake and targeted delivery, which facilitates higher intracellular concentrations of curcumin.
Discussion: Overall, the results indicate that PLA-PEG-based nanoparticles, functionalized with magnetic Fe₃O₄ and surface ligands, provide an effective platform for targeted curcumin delivery. These nanoparticles combine biocompatibility, controlled release, tumor-specific accumulation, and apoptosis induction, which collectively enhance therapeutic efficacy while minimizing systemic toxicity. The study underscores the potential of multifunctional nanocarriers as a promising approach for improving the effectiveness of anticancer therapies and offers a foundation for the further development of targeted, stimuli-responsive drug delivery systems.
Conclusion: As a final conclusion of this study, it can be stated that the development of novel drug delivery systems based on PLA-PEG copolymer nanoparticles is a promising and strategic step toward overcoming the therapeutic challenges of intractable diseases such as cancer. This study clearly demonstrated that the design of such nanocarriers not only offers high biocompatibility and safety for normal cells, but also, by taking advantage of the camouflage effect caused by PEG, increases blood circulation time and prevents premature elimination by the immune system. The outstanding feature of this system is the ability to control and intelligently release the drug in response to specific stimuli of the tumor microenvironment, especially higher acidity, which allows for maximum drug delivery to the target tissue and, subsequently, a significant reduction in systemic side effects. In this study, the effect of adding targeting ligands such as folic acid and glucose on the accuracy and efficiency of these nanoparticles in recognizing and binding to cancer cells was also clearly observed. In addition, the results of this study showed that the designed nanoparticles were successfully able to increase the induction of cell apoptosis in Hs-578T cancer cells. These findings strongly support the superiority of this nanotechnology compared to conventional drug formulations, both in increasing therapeutic efficacy and reducing toxicity. Overall, it can be concluded that PLA-PEG-based smart nanoparticles, with their multimodal capabilities, have great potential to become a comprehensive and reliable approach in the next generation of targeted cancer therapies, paving the way for further studies and ultimately effective clinical applications.