Mesenchymal Stem Cells (MSCs) are adult stem cells that are gaining worldwide attention for their multi-potential use in tissue engineering-based regenerative medicine. They can be obtained from numerous sources and one of the excellent sources is the dental tissue, such as Stem cells that are extracted from the Human Exfoliated Deciduous teeth (SHED). SHED are considered ideal due to their inherent characteristics, including the capability to proliferate quickly with minimal oncogenesis risk, multipotency capacity and their ability to suppress the immune system. On top of these positive cell traits, SHED are easily accessible with the patient's safety assured, posing less ethical issues and could also provide a sufficient number of cells for prospective clinical uses. This is primarily attributed to their ability to differentiate into multiple cell linages, including osteoblasts, odontoblasts, neuronal cells, adipocytes, as well as endothelial cells. Albeit SHED having a bright future, there still remains an obstacle to develop reliable experimental techniques to retain the long-term regeneration potential of the stem cells for prospective research and clinical applications. Therefore, this review aims to describe the various isolation, expansion and cryopreservation techniques used by researchers in this stem cell field. Optimization of these techniques is crucial to obtain distinct SHED culture with preserved stem cell properties, which enable more reproducible results that will be the key for further stem cell therapy development.
Biochar (BC) has attracted much attention owing to its superior sorption capacity towards ionized organic contaminants. However, the mechanism of ionized organics sorption occurring within BC containing large amounts of minerals is still controversial. In this study, we demonstrate the physicochemical structure of high-salinity microalgal residue derived biochar (HSBC) and elucidate the corresponding sorption mechanisms for four ionized dyes along with determining the crucial role of involved minerals. The results indicate that sodium and calcium minerals mainly exist within HSBCs, and the pyrolysis temperature can dramatically regulate the phases and interfacial property of both carbon matrix and minerals. As a result, the HSBC shows a higher sorption potential, benefiting from abundant functional groups and high content of inorganic minerals. Using theoretical calculations, the activities of electron donor-acceptor interaction between HSBCs and different dyes are clearly illustrated, thereby identifying the critical role of Ca2+ in enhancing the removal of ionized dyes in HSBCs. In addition, Ca-containing minerals facilitate the sorption of ionized dyes in HSBCs by forming ternary complexes through metal-bridging mechanism. These results of mineral-induced dye sorption mechanisms help to better understand the sorption of ionized organics in high-salt containing BC and provide a new disposal strategy for hazardous microalgal residue, as well as provide a breakthrough in making the remediation of ionized organic contaminated microalgal residue derived absorbent feasible.
The virulence of Vibrio parahaemolyticus is variable depending on its virulence determinants. A V. parahaemolyticus strain, in which the virulence is governed by the pirA and pirB genes, can cause acute hepatopancreatic necrosis disease (AHPND) in shrimps. Some V. parahaemolyticus that are non-AHPND strains also cause shrimp diseases and result in huge economic losses, while their pathogenicity and pathogenesis remain unclear. In this study, a non-AHPND V. parahaemolyticus, TJA114, was isolated from diseased Penaeus vannamei associated with a high mortality. To understand its virulence and adaptation to the external environment, whole-genome sequencing of this isolate was conducted, and its phenotypic profiles including pathogenicity, growth characteristics and nutritional requirements were investigated. Shrimps following artificial infection with this isolate presented similar clinical symptoms to the naturally diseased ones and generated obvious pathological lesions. The growth characteristics indicated that the isolate TJA114 could grow well under different salinity (10-55 p.p.t.), temperature (23-37 °C) and pH (6-10) conditions. Phenotype MicroArray results showed that this isolate could utilize a variety of carbon sources, amino acids and a range of substrates to help itself adapt to the high hyperosmotic and alkaline environments. Antimicrobial-susceptibility test showed that it was a multidrug-resistant bacterium. The whole-genomic analysis showed that this V. parahaemolyticus possessed many important functional genes associated with multidrug resistance, stress response, adhesions, haemolysis, putative secreted proteases, dedicated protein secretion systems and a variety of nutritional metabolic mechanisms. These annotated functional genes were confirmed by the phenotypic profiles. The results in this study indicated that this V. parahaemolyticus isolate possesses a high pathogenicity and strong environmental adaptability.
Styphnolobium japonicum (L.) Schott (family Fabaceae Juss.) also called pagoda tree, is widely planted in northern China in landscape plantings, for erosion control and forestry. In recent years, symptoms of branch dieback were observed on S. japonicum in the southern part of Xinjiang province, China. From 2019 to 2022, in total ca. 1000 ha area was surveyed in Korla (41.68°N, 86.06°E), Bohu (41.95°N, 86.53°E) and Alaer (41.15°N, 80.29°E). Typical symptoms were observed in 70% of the surveyed branches. To identify the cause, we collected 50 symptomatic branches. Symptoms were initially observed on green current-year twigs, which turned grayish white in color. In the later stages of disease development, a large number of nacked black conidia formed under epidermis of perennial branches, causing visible black protrusions (pycnidia) on branch surface. The disease occurred throughout the entire growing season of S. japonicum. Symptoms also occurred on the inflorescence, fruit, and twigs. In some cases, infection resulted in tree mortality. Isolations were made from the margin between healthy and diseased tissues. Small pieces were excised, surface disinfested (75% ethanol 30 s, 1% NaClO solution 5 mins), cut into pieces (5 to 10 mm2), and incubated on PDA medium at 28℃ for 3 days. A total of 16 isolates (GH01-GH16) with similar colony morphology were obtained. The colonies were initially white, gradually turning to olive-green on the surface and black on the underside after 7 days. Microscopically, the conidia were aseptate, 1-septate, two-septate, and muriform, 2.6-4.5 × 2.9-27.6 μm (n=50). Pycnidia ranged in size from 120.2 to 135.5 × 112.4 to 118.6 µm (n=20). Those morphological characters matched the descriptions of Neoscytalidium dimidiatum (previously N. novaehollandiae) (Alizadeh et al. 2022; Pavlic et al. 2008). For molecular identification, genomic DNA of GH01-GH16 were extracted from fresh mycelia. The internal transcribed spacer (ITS), large subunit ribosomal RNA gene (LSU), and translation elongation factor 1-alpha (EF1-α) gene were amplified using the primer sets ITS1/ITS4 (White 1990), LRoR/LR5 (Vilgalys and Hester 1990) and EF1-728F/EF1-986R (Carbone and Kohn 1999). The sequences were deposited in GenBank (accession No. OP379832, OQ096643-OQ096657 for ITS, OP389048, OQ127403-OQ127417 for LSU, and OQ136617, OQ586044-OQ586058 for EF1-α). The ITS sequence had 100% identity (505/505 bp) to MT362600. Similarly, the LSU and EF1-α sequences were found to be identical to MW883823 (100%, 821/821 bp) and KX464763(99%, 256/258 bp), respectively. Pathogenicity was tested on one-year-old healthy S. japonicum seedlings. Spores of representative isolate GH01 were produced on PDA by incubating for 7-days at 28℃. Conidia were washed with sterile water. Five trees were inoculated with 1 × 106 conidia/ml conidial suspensions and five trees were sprayed with sterile water. All trees were covered with plastic bags for 24 h and kept at 25°C in a greenhouse. Signs and symptoms were similar to those observed in field collections one month after inoculation, while no symptoms occurred on the controls. The original fungus was successfully reisolated from the inoculated trees and was identified as N. dimidiatum following the methods described above. N. dimidiatum has been reported in many Asian country such as Malaysia, India, Turkey, and Iran(Akgül et al. 2019; Alizadeh et al. 2022; Khoo et al. 2023; Salunkhe et al. 2023). To our knowledge, this is the first report of N. dimidiatum associated with branch dieback of S. japonicum in China. Our findings have expanded the host range of N. dimidiatum in China and provides a theoretical basis for the diagnosis and treatment of the disease.
Deoxyribonucleic acid (DNA) emerges as building bricks for the fabrication of nanostructure with complete artificial architecture and geometry. The amazing ability of DNA in building two- and three-dimensional structures raises the possibility of developing smart nanomachines with versatile controllability for various applications. Here, we overviewed the recent progresses in engineering DNA machines for specific bioengineering and biomedical applications.
Regenerative medicine has rapidly evolved over the past decade owing to its potential applications to improve human health. Targeted differentiations of stem cells promise to regenerate a variety of tissues and/or organs despite significant challenges. Recent studies have demonstrated the vital role of the physical microenvironment in regulating stem cell fate and improving differentiation efficiency. In this review, we summarize the main physical cues that are crucial for controlling stem cell differentiation. Recent advances in the technologies for the construction of physical microenvironment and their implications in controlling stem cell fate are also highlighted.
Balancing the biodegradability and mechanical integrity of a bioresorbable scaffold (BRS) with time after implantation to match the remodeling of the scaffolded blood vessel is important, but a key challenge in doing so remains. This study presents a novel intercalated structure of a metallic BRS by introducing a nanoscale Zn sacrificial layer between the nitrided Fe platform and the sirolimus-carrying poly(d,l-lactide) drug coating. The PDLLA-Zn-FeN BRS shows a multistage biodegradation behavior, maintaining mechanical integrity at the initial stage and exhibiting accelerated biodegradation at the subsequent stage in both rabbit abdominal aortas and human coronary arteries, where complete biodegradation was observed about 2 years after implantation. The presence of the nanoscale Zn sacrificial layer with an adjustable thickness also contributes to the tunable biodegradation of BRS and allows the reduction of the metallic strut thickness to 53 μm, with radial strength as strong as that of the current permanent drug-eluting stents.