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Chitosan (CS) nanofibers were prepared by an electrospinning technique and then treated with simulated body fluid (SBF) to encourage hydroxyapatite (HA) formation on their surface. The CS/HA nanofibers were subjected to scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy, and X-ray diffraction (XRD) to confirm HA formation as well as determine the morphology of the nanofibrous scaffolds. The SEM image indicated that the distribution of HA on the CS nanofibers was homogeneous. The results from EDS and XRD indicated that HA was formed on the nanofibrous surfaces after 6-day incubation in the SBF. The calcium/phosphorus ratio of deposited HA was close to that of natural bone. To determine biocompatibility, the CS/HA scaffolds were applied to the culture of rat osteosarcoma cell lines (UMR-106). The cell densities on the CS/HA nanofibers were higher than those on the CS nanofibers, the CS/HA film, and the CS film, indicating that cell proliferation on CS/HA nanofibers was enhanced. Moreover, the early osteogenic differentiation on CS/HA was also more significant, due to the differences in chemical composition and the surface area of CS/HA nanofibers. The biocompatibility and the cell affinity were enhanced using the CS/HA nanofibers. This indicates that electrospun CS/HA scaffolds would be a potential material in bone tissue engineering.

In this study, chitosan/hydroxyapatite (CS/HA) nanofibers were prepared using a wet chemical method. First, CS nanofibers with uniform diameters were fabricated using electrospinning. Then, a wet chemical process was used to mineralize nanofiber surfaces to form a homogeneous HA deposit. Reactions with three cycles were found to optimize biomimetic properties of the HA. The mineralization process required only approximately 3 h, which corresponded to a saving of 98 % in preparation time compared with that needed by the process using a simulated body fluid (SBF). According to the attachment and spreading of UMR (rat osteosarcoma) cells on the CS/HA composite fibers, the deposited mineralization layer significantly enhanced cell affinity of the CS nanofibers and the HA created by the wet chemical method was as effective as that created by the SBF. The composite nanofibrous scaffolds produced by the wet chemical process also promoted osteogenic differentiation by inducing ossification. Thus, expressions of collagen type I, alkaline phosphatase, osteocalcin, bone sialoprotein, and osterix were all enhanced. These results demonstrated that composite electrospun fibers can be efficiently prepared using wet chemical method and the resulting nanofibrous scaffolds have considerable potential in future bone tissue engineering applications.

Homalomena vietnamensis is a rare species of the Homalomena genus and only found in Middle region of Vietnam. In this study, we found 10 compounds in ethanol extracts of leaf and rhizome of H. vietnamensis, such as cadinane-4β,5α,10α-triol, oplopanone, 4-epi-oplopananol, 2α-hydroxy homalomenol A, 1β,4β,7β-Trihydroxyeudesmane, homalomentetraol, 4-acetoxyoplopananol, 5,7-diepi-2a-acetoxyoplopanone, eudesma 4β, 7α- diol-1β-fumarate), and homalomenol F, via liquid chromatography-mass spectrometry (LC/MS). Moreover, the antibacterial activity of ethanol extracts of leaf and rhizome from this species has been evaluated by disc diffusion method for the first time. The results showed that rhizome extract of could inhibit the growth of 5 tested micro-organisms, including of Bacillus cereus (28.3 ± 1.5 mm), Salmonella enteritidis (19.5 ± 1.5 mm), Staphylococcus aureus (16.3 ± 1.5 mm), Escherichia coli (14.7 ± 1.2 mm), and Pseudomonas aeruginosa (8.2 ± 0.8 mm), while the leaf extract showed antibacterial effect against Bacillus cereus (22.0 ± 2.0 mm), S. enteritidis (14.7 ± 0.6 mm), and S. aureus (12.5 ± 1.8 mm).

Typhonium thatsonense Luu & H. T. Van (Araceae) is described and illustrated as a new species from the That Son Mountains, Mekong Delta, Vietnam. It most closely resembles T. supraneeae A. Galloway, Petra Schmidt & Sinhab. in its trifoliolate leaves and general appearance of the inflorescence but differs in many leaf and floral characters.

Wax apple (Syzygium samarangense) is a popular species with high economic value in Vietnam and other countries in Asia. This research analyzed and compared morphological and molecular characteristics (ITS and trnL-F sequences) of 5 varieties of wax apple in Dong Thap Province, Vietnam, including of An Phuoc, Xanh Duong, Hong Dao, Hoa An, and Sua wax apples. The results revealed that five varieties of wax apples had a board range of morphological characteristics, especially in shape, color, and size of fruits. Furthermore, molecular analysis results showed that ITS and trnL-F sequences of four varieties of wax apples, including of Xanh Duong, Hong Dao, Hoa An, and Sua, were identical with 100 % similarity whereas An Phuoc wax apple had differences in one and five positions in ITS and trnL-F sequences as compared to other varieties. The phylogenetic tree was established by comparison of ITS sequences of five varieties in this study and other varieties in Genbank (NCBI) and showed that four varieties of wax apples (Xanh Duong, Hong Dao, Hoa An, and Sua) were 100 % match with two varieties grown in China (kC815987, KC800610) and one variety planted in Sri Lanka (MN104146). On the other hand, ITS sequence of An Phuoc wax apple was high similarity with another wax apple variety planted in Sri Lanka (MN104142).

In this study, cell–material adhesive strength and cellular mechanical properties were measured using atomic force microscopy (AFM) to track cell attachment and osteogenic differentiation. First, chitosan substrates were treated with simulated body fluid (SBF) for various periods, resulting in substrates with different osteoconductivity. The X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and in vitro tests revealed that the biomimeticity and osteoconductivity of substrates increased with increasing time of SBF treatment. When the SBF immersion exceeded 14 days, the chitosan substrates exhibited their highest biocompatibility and osteoconductivity. AFM measurements indicated specifically high adhesive forces between SBF-treated chitosan and osteogenic cells, causing better cell attachment. The results demonstrate that cell adhesion was controlled by cell–material adhesive strength, which were in turn controlled via the SBF treatment time. The adhesive strength between cells and material also accounted for the chitosan substrates’ specific selectivity toward osteogenic cells. A two-step increase in mechanical strength was observed for the nucleus and cytoplasm of osteogenic cells. The results indicate that through the use of AFM, the real-time cell–material interforce and cellular mechanics can be identified. The adhesive strength was positively correlated to the cell attachment, and the second increase in the Young’s modulus of nucleus and cytoplasm was correlated to early osteogenic differentiation.

Graphene oxide (GO) is a promising material for the adsorption of contaminants from wastewater. In this study, a GO-based composite with high adsorption capacity and reduced GO content was synthesized by incorporating TEMPO-oxidized cellulose nanospheres (TO-CNS) derived from pineapple leaves. TO-CNS were effectively integrated into GO via a one-pot reaction based on Hummer’s method. In this process, TEMPO oxidation selectively converted the –CH 2 OH groups on cellulose nanospheres into –COOH groups, all while preserving the crystalline structure of cellulose I. Notably, the in situ integration of TO-CNS as a co-support during graphite oxidation significantly enhanced the interlayer spacing of GO sheets, expanding it from 0.34 to 0.85 nm. This increase in spacing, indicative of robust interfacial interactions, was further validated using FTIR spectroscopy. The spectra revealed hydrogen bonding and pronounced shifts in the mode and position of the functional group peaks, underscoring the structural alterations induced by TO-CNS integration. Raman spectroscopy revealed increased graphitic defects, and thermal analysis confirmed structural integration. The composite's average pore size of 40 Å demonstrated a significant enhancement that facilitated adsorption compared to 26 Å in GO. Ciprofloxacin adsorption capacities (35.95 ± 0.54–38.47 ± 0.53 mg/g) were comparable to pure GO (35.08 ± 1.10–36.83 ± 1.12 mg/g) despite a reduced GO content (73.8/26.2 wt%). Zeta potential analysis highlighted the roles of electrostatic attraction, hydrogen bonding, and π–π stacking in adsorption. This GO/TO-CNS composite demonstrates the potential for efficient, sustainable, and biocompatible antibiotic adsorption, offering significant promise for environmental remediation.

Introduction: Arisaema liemiana was newly identified as a new species for the flora of Vietnam in 2020. It was discovered in Takou Nature Reserve, Binh Thuan province, Vietnam, characterized by its height of 20-50 centimeters, deciduous nature, light yellow spathe limb, white spathe tube, and spadix appendix covered with filiform neuter structures. Aim: This study aimed to investigate the chemical components and antibacterial activity of the acetone extracts derived from the aerial parts and tubers of A. liemiana. Methodology: A. liemiana specimens were collected from Takou Mountain within Takou Nature Reserve, Binh Thuan Province, and subjected to acetone extraction. The chemical components of these extracts were analyzed using GC-MS, while the antibacterial activity was assessed through the agar disc diffusion method. Results: A total of 57 compounds were identified in the aerial part and tuber extracts of which 32 components were found in the first extract while the latter one contained 34 constituents. The antibacterial effectiveness of the tuber acetone extracts was assessed against 10 bacterial strains, revealing diverse inhibition zones. Notably, S. aureus ATCC 25923 exhibited the largest inhibition zone diameter, followed by B. cereus, V. parahaemolyticus, S. flexneri, P. aeruginosa, E. coli, L. monocytogenes, S. saprophyticus, S. typhimurium, and S. enteritidis. Conclusion: The chemical composition and antibacterial properties of acetone extracts derived from Arisaema liemiana was investigated for the first time. The observed notable antibacterial efficacy suggests potential pharmacological implications of A. liemiana. Additionally, this research unveils broader applications of A. liemiana in herbal medicine. Introducción: Arisaema liemiana fue identificada recientemente como una nueva especie para la flora de Vietnam en 2020. Fue descubierta en la Reserva Natural de Takou, provincia de Binh Thuan, Vietnam, caracterizada por su altura de 20-50 centímetros, naturaleza caducifolia, extremidad de espata de color amarillo claro, tubo de espata blanco y apéndice del espádice cubierto de estructuras neutras filiformes. Objetivo: Este estudio tuvo como objetivo investigar los componentes químicos y la actividad antibacteriana de los extractos de acetona derivados de las partes aéreas y tubérculos de A. liemiana. Metodología: Los especímenes de A. liemiana se recolectaron de la montaña Takou dentro de la Reserva Natural de Takou, provincia de Binh Thuan, y se sometieron a extracción con acetona. Los componentes químicos de estos extractos se analizaron mediante GC-MS, mientras que la actividad antibacteriana se evaluó mediante el método de difusión en disco de agar. Resultados: Se identificaron 57 compuestos en los extractos de la parte aérea y del tubérculo, de los cuales 32 componentes se encontraron en el primer extracto, mientras que el último contenía 34 constituyentes. Se evaluó la eficacia antibacteriana de los extractos de acetona del tubérculo frente a 10 cepas bacterianas, lo que reveló diversas zonas de inhibición. Cabe destacar que S. aureus ATCC 25923 exhibió el mayor diámetro de zona de inhibición, seguido de B. cereus, V. parahaemolyticus, S. flexneri, P. aeruginosa, E. coli, L. monocytogenes, S. saprophyticus, S. typhimurium y S. enteritidis. Conclusión: Se investigó por primera vez la composición química y las propiedades antibacterianas de los extractos de acetona derivados de Arisaema liemiana. La notable eficacia antibacteriana observada sugiere posibles implicaciones farmacológicas de A. liemiana. Además, esta investigación revela aplicaciones más amplias de A. liemiana en la medicina herbal. Introdução: Arisaema liemiana foi recentemente identificada como uma nova espécie para a flora do Vietnã em 2020. Foi descoberta na Reserva Natural de Takou, província de Binh Thuan, Vietnã, caracterizada por sua altura de 20-50 centímetros, natureza caducifólia, membro de espata amarelo claro, tubo de espata branco e apêndice de espádice coberto com estruturas neutras filiformes. Objetivo: Este estudo teve como objetivo investigar os componentes químicos e a atividade antibacteriana dos extratos de acetona derivados das partes aéreas e tubérculos de A. liemiana. Metodologia: Espécimes de A. liemiana foram coletados da Montanha Takou dentro da Reserva Natural de Takou, Província de Binh Thuan, e submetidos à extração de acetona. Os componentes químicos desses extratos foram analisados usando GC-MS, enquanto a atividade antibacteriana foi avaliada através do método de difusão em disco de ágar. Resultados: Um total de 57 compostos foram identificados na parte aérea e extratos de tubérculos, dos quais 32 componentes foram encontrados no primeiro extrato, enquanto o último continha 34 constituintes. A eficácia antibacteriana dos extratos de acetona de tubérculos foi avaliada contra 10 cepas bacterianas, revelando diversas zonas de inibição. Notavelmente, S. aureus ATCC 25923 exibiu o maior diâmetro de zona de inibição, seguido por B. cereus, V. parahaemolyticus, S. flexneri, P. aeruginosa, E. coli, L. monocytogenes, S. saprophyticus, S. typhimurium e S. enteritidis. Conclusão: A composição química e as propriedades antibacterianas dos extratos de acetona derivados de Arisaema liemiana foram investigadas pela primeira vez. A notável eficácia antibacteriana observada sugere potenciais implicações farmacológicas de A. liemiana. Além disso, esta pesquisa revela aplicações mais amplas de A. liemiana na medicina herbal.