Islamic Azad University North Tehran Branch

Composite nanofibers of polyvinyl alcohol/carboxymethyl cellulose/collagen (PVA/CMC/Col) were successfully fabricated using the electrospinning method, incorporating various proportions of each component. These nanofibers were meticulously characterized using advanced analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and mechanical testing, to ensure a comprehensive understanding of their structural and functional properties. The resulting nanofibers displayed a uniaxial structure with mean diameters ranging from 224 to 408 nm, showcasing precise control over the electrospinning process. The results revealed a direct correlation between material composition and performance, with the PCC5 formulation emerging as the optimal sample. This was evidenced by FTIR and TGA data, which confirmed that an increased collagen concentration led to a more integrated polymer network with enhanced intermolecular hydrogen bonding and superior thermal stability. Furthermore, mechanical testing demonstrated that the PCC5 sample exhibited the highest tensile strength, solidifying the link between chemical composition and robust physical properties. The biocompatibility of the nanofibers was rigorously evaluated through in vitro testing on MG-63 osteoblast-like cells using the MTT assay. The results revealed excellent compatibility with the cellular environment, with the PCC5 sample consistently promoting the highest rates of cell adhesion and proliferation. This study underscores the groundbreaking potential of PVA/CMC/Col nanofibers in the field of bone tissue engineering, as their optimized blend of physical and biological properties makes them a promising candidate for bone regeneration applications. This research paves the way for future advancements in regenerative medicine, offering a robust platform for further exploration and innovation.

Plant sexual reproduction involves highly structured and specialized organs: stamens (male) and gynoecium (female, containing ovules). These organs synchronously develop within protective flower buds. Investigating ovules and pollen is crucial for understanding aspects of fertility and sterility in plants. Research on their development and embryogenesis plays a significant role in determining the taxonomic relationships of various species. Paraffin-embedding associated to examination with light microscope showed the development of ovules and pollen grains in Camelina sativa, a key oilseed crop. The findings indicated that the anthers exhibit tetrasporangiate characteristics, with the anther wall consisting of the epidermis, mechanical layer, transitional layer, and tapetum. The microsporogenesis type is simultaneous and microspore tetrads arrange in tetrahedral tetrads. Scanning electron microscope observations showed that mature pollen grains have a tricolporate aperture and are medium-sized, with microreticulate exine ornamentation on the pollen wall. The gynoecium is characterized as bicarpellate, and the ovule in its mature state is classified as amphitropous and bitegmic. The meiosis division of megasporocytes yields a linear tetrad formation. The eight-nucleate embryo sac following the Polygonum type pattern. With a broader systematic perspective, these embryological and palynological features demonstrate evolutionary conservatism within the Brassicaceae, with minor distinctions potentially representing adaptive changes.

ABSTRACT This study explores the chemical composition, antimicrobial synergy and antioxidant properties of essential oil blends from Thymus vulgaris , Origanum vulgare , Rosmarinus officinalis , Lavandula angustifolia and Cinnamomum verum as natural preservatives in anti‐ageing cosmetic emulsions. Gas chromatography–mass spectrometry (GC–MS) identified key bioactives (thymol 45.23%, carvacrol 72.56%, trans‐cinnamaldehyde 74.32%), driving broad‐spectrum activity against Staphylococcus aureus , Pseudomonas aeruginosa , Escherichia coli , Candida albicans and Aspergillus brasiliensis . Synergistic blends (e.g., thyme‐oregano, FICI ≤ 0.375) reduced minimum inhibitory concentrations by 50%, meeting ISO 11930:2019 standards (> 3 log reduction for bacteria, > 1 for fungi by Day 14). Antioxidant properties maintained peroxide values at 3.67 meq O 2 /kg and TBARS at 0.56 mg MDA/kg over 6 months at 40°C, extending shelf‐life by 2–3 months. Statistical validation (ANOVA, Tukey's test, p < 0.01) confirmed efficacy and stability. Sensory scores (> 7.5/9) highlight consumer appeal. These analytical insights underscore the potential of essential oil blends as sustainable alternatives to synthetic preservatives, with implications for analytical chemistry in cosmetic material development.