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1.
Microsyst Nanoeng ; 10: 102, 2024.
Article in English | MEDLINE | ID: mdl-39045232

ABSTRACT

With the rapid development of various fields, including aerospace, industrial measurement and control, and medical monitoring, the need to quantify flow velocity measurements is increasing. It is difficult for traditional flow velocity sensors to fulfill accuracy requirements for velocity measurements due to their small ranges, susceptibility to environmental impacts, and instability. Herein, to optimize sensor performance, a flexible microelectromechanical system (MEMS) thermal flow sensor is proposed that combines the working principles of thermal loss and thermal temperature difference and utilizes a flexible cavity substrate made of a low-thermal-conductivity polyimide/SiO2 (PI/SiO2) composite porous film to broaden the measurement range and improve the sensitivity. The measurement results show that the maximum measurable flow velocity can reach 30 m/s with a resolution of 5.4 mm/s. The average sensitivities of the sensor are 59.49 mV/(m s-1) in the medium-to-low wind velocity range of 0-2 m/s and 467.31 mV/(m s-1) in the wind velocity range of 2-30 m/s. The sensor proposed in this work can enable new applications of flexible flow sensors and wearable devices.

2.
Microsyst Nanoeng ; 10: 103, 2024.
Article in English | MEDLINE | ID: mdl-39045231

ABSTRACT

Wearable devices, such as data gloves and electronic skins, can perceive human instructions, behaviors and even emotions by tracking a hand's motion, with the help of knowledge learning. The shape or position single-mode sensor in such devices often lacks comprehensive information to perceive interactive gestures. Meanwhile, the limited computing power of wearable applications restricts the multimode fusion of different sensing data and the deployment of deep learning networks. We propose a perceptive fusion electronic skin (PFES) with a bioinspired hierarchical structure that utilizes the magnetization state of a magnetostrictive alloy film to be sensitive to external strain or magnetic field. Installed at the joints of a hand, the PFES realizes perception of curvature (joint shape) and magnetism (joint position) information by mapping corresponding signals to the two-directional continuous distribution such that the two edges represent the contributions of curvature radius and magnetic field, respectively. By autonomously selecting knowledge closer to the user's hand movement characteristics, the reinforced knowledge distillation method is developed to learn and compress a teacher model for rapid deployment on wearable devices. The PFES integrating the autonomous learning algorithm can fuse curvature-magnetism dual information, ultimately achieving human machine interaction with gesture recognition and haptic feedback for cross-space perception and manipulation.

3.
Mater Today Bio ; 27: 101141, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39045312

ABSTRACT

Congenital microtia is the most common cause of auricular defects, with a prevalence of approximately 5.18 per 10,000 individuals. Autologous rib cartilage grafting is the leading treatment modality at this stage of auricular reconstruction currently. However, harvesting rib cartilage may lead to donor site injuries, such as pneumothorax, postoperative pain, chest wall scarring, and deformity. Therefore, in the pursuit of better graft materials, biomaterial scaffolds with great histocompatibility, precise control of morphology, non-invasiveness properties are gradually becoming a new research hotspot in auricular reconstruction. This review collectively presents the exploit and application of 3D printing biomaterial scaffold in auricular reconstruction. Although the tissue-engineered ear still faces challenges before it can be widely applied to patients in clinical settings, and its long-term effects have yet to be evaluated, we aim to provide guidance for future research directions in 3D printing biomaterial scaffold for auricular reconstruction. This will ultimately benefit the translational and clinical application of cartilage tissue engineering and biomaterials in the treatment of auricular defects.

4.
Article in English | MEDLINE | ID: mdl-39046716

ABSTRACT

BACKGROUND: ChatGPT and other ChatBots have emerged as tools for interacting with information in manners resembling natural human speech. Consequently, the technology is used across various disciplines, including business, education, and even in biomedical sciences. There is a need to better understand how ChatGPT can be used to advance gerontology research. Therefore, we evaluated ChatGPT responses to questions on specific topics in gerontology research, and brainstormed recommendations for its use in the field. METHODS: We conducted semi-structured brainstorming sessions to identify uses of ChatGPT in gerontology research. We divided a team of multidisciplinary researchers into four topical groups: a) gero-clinical science, b) basic geroscience, c) informatics as it relates to electronic health records (EHR), and d) gero-technology. Each group prompted ChatGPT on a theory-, methods-, and interpretation-based question and rated responses for accuracy and completeness based on standardized scales. RESULTS: ChatGPT responses were rated by all groups as generally accurate. However, the completeness of responses was rated lower, except by members of the informatics group, who rated responses as highly comprehensive. CONCLUSIONS: ChatGPT accurately depicts some major concepts in gerontological research. However, researchers have an important role in critically appraising the completeness of its responses. Having a single generalized resource like ChatGPT may help summarize the preponderance of evidence in the field to identify gaps in knowledge and promote cross-disciplinary collaboration.

5.
Bioresour Bioprocess ; 11(1): 68, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39012554

ABSTRACT

To understand the ecology of species and promote biotechnology through beneficial strain selection for improving starch yield in maize wet-milling steeping, bacterial diversity and community structure during the counter-current steeping process in a commercial steeping system were characterized and investigated. The microbial diversity in the steeping liquor, which consisted of 16 phyla, 131 families, and 290 genera, was more abundant compared to those present on the surface of unsteeped maize. As the counter-current steeping progressed, exposing newer maize to the older steepwater, Lactobacillus dominated, replacing Rahnella, Pseudomonas, Pantoea, and Serratia. The thermophilic and acidophilic microbial consortia were enriched through adaptive evolution engineering and employed to improve starch yield. Several steeping strategies were evaluated, including water alone, SO2 alone, mono-culture of B. coagulans, microbial consortia, and a combination of consortium and SO2. Combining the microbial consortium with SO2 significantly increased the starch yield to, about 66.4 ± 0.5%, a 22% and 46% increase over SO2 alone and the consortium alone, respectively. Scanning electron microscope (SEM) of steeped maize structure indicated that the combination of consortium and SO2 disrupted the protein matrix and widened gaps between starch granules in maize endosperm. This released proteins into the steepwater and left starch granules in the aleurone layer. The steeping strategy of using thermophilic and acidophilic microbial consortium as additives shows potential application as an environmentally friendly alternative to conventional maize steeping procedures.

6.
Bioresour Technol ; 407: 131116, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39019197

ABSTRACT

Methane, a potent greenhouse gas, requires sustainable mitigation strategies. Here, the microbial upcycling of methane to phytoene, a valuable colorless carotenoid with applications in the cosmeceutical industry was demonstrated. To achieve this goal, a stepwise metabolic engineering approach was employed in Methylocystis sp. MJC1, a methane-oxidizing bacterium. The incorporation of crtE and crtB genes from Deinococcus radiodurans R1 established the phytoene biosynthetic pathway. This pathway was fine-tuned through promoter optimization, resulting in a phytoene production of 450 µg/L from 37 mmol/L methane. Disrupting the ackA gene reduced a by-product, acetate, by 50 % and increased phytoene production by 56 %. Furthermore, overexpressing the dxs gene boosted phytoene titer 3-fold. The optimized strain produced 15 mg/L phytoene from 2 mol/L methane in fed-batch fermentation, a 4-fold increase in phytoene titer and 4-fold in yield. This demonstrates Methylocystis sp. MJC1's potential for efficient phytoene production and presents a novel approach for greenhouse gas reduction.

7.
Synth Syst Biotechnol ; 9(4): 766-774, 2024 Dec.
Article in English | MEDLINE | ID: mdl-39021363

ABSTRACT

The anti-Clostridium difficile infection (CDI) drug fidaxomicin is a natural polyketide metabolite mainly produced by Micromonosporaceae, such as Actinoplanes deccanensis, Dactylosporangium aurantiacum, and Micromonospora echinospora. In the present study, we employed a stepwise strategy by combining heterologous expression, chassis construction, promoter engineering, activator and transporters overexpression, and optimization of fermentation media for high-level production of fidaxomicin. The maximum yield of 384 mg/L fidaxomicin was achieved with engineered Streptomyces albus D7-VHb in 5 L-tank bioreactor, and it was approximately 15-fold higher than the native strain Actinoplanes deccanensis YP-1 with higher strain stability and growth rate. This study developed an enhanced chassis strain, and for the first time, achieved the heterologous synthesis of fidaxomicin through a combinatorial metabolic engineering strategy.

8.
Am J Stem Cells ; 13(3): 152-161, 2024.
Article in English | MEDLINE | ID: mdl-39021375

ABSTRACT

BACKGROUND: Replacing damaged organs or tissues and repairing damage by tissue engineering are attracting great interest today. A potentially effective method for bone remodeling involves combining nanofiber scaffolds with extracellular matrix (ECM), and growth factors. Today, electrospun PCL-based scaffolds are widely used for tissue engineering applications. METHODS: In this study, we used an electrospun polycaprolactone (PCL) scaffold coated with fibronectin (Fn), a ubiquitous ECM glycoprotein, to investigate the induction potential of this scaffold in osteogenesis with adipose-derived mesenchymal stem cells (AD-MSCs). RESULTS: Scanning electron microscopy (SEM) analysis showed that fibronectin, by binding to the membrane receptors of mesenchymal stem cells (MSCs), leads to their attachment and proliferation on the PCL scaffold and provides a suitable environment for osteogenesis. In addition, biochemical tests showed that fibronectin leads to increased calcium deposition. The results also showed that alkaline phosphatase activity was significantly higher in the PCL scaffold coated with fibronectin than in the control groups (PCL scaffold group and tissue culture polystyrene (TCPS) group) (P<0.05). Also, the analysis of quantitative reverse transcription PCR (qRT-PCR) data showed that the relative expression of bone marker genes such as osteonectin (ON), osteocalcin (OC), RUNX family transcription factor 2 (RUNX2), and collagen type I alpha 1 (COL1) was much higher in the cells seeded on the PCL/Fn scaffold than in the other groups (P<0.05). CONCLUSIONS: The results show that fibronectin has an increasing effect in accelerating bone formation and promising potential for use in bone tissue engineering.

9.
Microsyst Nanoeng ; 10: 99, 2024.
Article in English | MEDLINE | ID: mdl-39021529

ABSTRACT

Supramolecules are considered as promising materials for volatile organic compounds (VOCs) sensing applications. The proper understanding of the sorption process taking place in host-guest interactions is critical in improving the pattern recognition of supramolecules-based sensing arrays. Here, we report a novel approach to investigate the dynamic host-guest recognition process by employing a bulk acoustic wave (BAW) resonator capable of producing multiple oscillation amplitudes and simultaneously recording multiple responses to VOCs. Self-assembled monolayers (SAMs) of ß-cyclodextrin (ß-CD) were modified on four BAW sensors to demonstrate the gas-surface interactions regarding oscillation amplitude and SAM length. Based on the method, a virtual sensor array (VSA) type electronic nose (e-nose) can be realized by pattern recognition of multiple responses at different oscillation amplitudes of a single sensor. VOCs analysis was realized respectively by using principal component analysis (PCA) for individual VOC identification and linear discriminant analysis (LDA) for VOCs mixtures classification.

10.
iScience ; 27(7): 110211, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39021798

ABSTRACT

Metal-organic frameworks (MOFs) are functional materials that are proving to be indispensable for the development of next-generation batteries. The porosity, crystallinity, and abundance of active sites in MOFs, which can be tuned by selecting the appropriate transition metal/organic linker combination, enable MOFs to meet the performance requirements for cathode materials in batteries. Recent studies on the use of MOFs in cathodes have verified their high durability, cyclability, and capacity thus demonstrating the huge potential of MOFs as high-performance cathode materials. However, to keep pace with the rapid growth of the battery industry, several challenges hindering the development of MOF-based cathode materials need to be overcome. This review analyzes current applications of MOFs to commercially available lithium-ion batteries as well as advanced batteries still in the research stage. This review provides a comprehensive outlook on the progress and potential of MOF cathodes in meeting the performance requirements of the future battery industry.

11.
Heliyon ; 10(12): e32864, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-39021919

ABSTRACT

Hydrogels exhibit exceptional suitability as wound dressing due to their remarkable three-dimensional (3D) characteristics. Here, we have reported the fabrication of hydrogels from biopolymers carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and gelatin via a simple blending method to mimic the natural extracellular matrix. Scanning electron microscopy (SEM), water contact meters (WCM), and Fourier-transform infrared spectroscopy (FTIR) were used to evaluate the chemical structural, morphological, and wettability behavior. The wetting and degradation behavior were also found to be different for different formulations (Min. (51.60o) and Max. (113.60o)) and (Min. (38.82 mg) and Max. (3.72 mg)), respectively. Swelling was investigated in different media, including phosphate buffer saline solution (PBS) and aqueous media. It was observed that the hydrogel displayed the highest degree of swelling in an aqueous medium (Min. (597.32-1121.49 %) and Max. (1089.51-2139.73 %)) compared to PBS media (Min. (567.01-1021.85 %) and Max. (899.13-1639.17 %)). The release of Neomycin was studied in a PBS medium via the Franz diffusion method at 37 °C. The maximal release in various media demonstrated pH-responsive behavior. The viability and proliferation of fibroblast (3T3) cell lines were examined in vitro to evaluate cytocompatibility. Human Embryonic Kidney (HEK) 293 cells were used to evaluate the hydrogels' ability to promote vascularization and angiogenesis. Therefore, the data demonstrate that hydrogels that have been manufactured have qualities that make them promising for use as wound dressings in wound healing applications.

12.
JMIR Public Health Surveill ; 10: e52353, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39024001

ABSTRACT

BACKGROUND: Multimorbidity is a significant public health concern, characterized by the coexistence and interaction of multiple preexisting medical conditions. This complex condition has been associated with an increased risk of COVID-19. Individuals with multimorbidity who contract COVID-19 often face a significant reduction in life expectancy. The postpandemic period has also highlighted an increase in frailty, emphasizing the importance of integrating existing multimorbidity details into epidemiological risk assessments. Managing clinical data that include medical histories presents significant challenges, particularly due to the sparsity of data arising from the rarity of multimorbidity conditions. Also, the complex enumeration of combinatorial multimorbidity features introduces challenges associated with combinatorial explosions. OBJECTIVE: This study aims to assess the severity of COVID-19 in individuals with multiple medical conditions, considering their demographic characteristics such as age and sex. We propose an evolutionary machine learning model designed to handle sparsity, analyzing preexisting multimorbidity profiles of patients hospitalized with COVID-19 based on their medical history. Our objective is to identify the optimal set of multimorbidity feature combinations strongly associated with COVID-19 severity. We also apply the Apriori algorithm to these evolutionarily derived predictive feature combinations to identify those with high support. METHODS: We used data from 3 administrative sources in Piedmont, Italy, involving 12,793 individuals aged 45-74 years who tested positive for COVID-19 between February and May 2020. From their 5-year pre-COVID-19 medical histories, we extracted multimorbidity features, including drug prescriptions, disease diagnoses, sex, and age. Focusing on COVID-19 hospitalization, we segmented the data into 4 cohorts based on age and sex. Addressing data imbalance through random resampling, we compared various machine learning algorithms to identify the optimal classification model for our evolutionary approach. Using 5-fold cross-validation, we evaluated each model's performance. Our evolutionary algorithm, utilizing a deep learning classifier, generated prediction-based fitness scores to pinpoint multimorbidity combinations associated with COVID-19 hospitalization risk. Eventually, the Apriori algorithm was applied to identify frequent combinations with high support. RESULTS: We identified multimorbidity predictors associated with COVID-19 hospitalization, indicating more severe COVID-19 outcomes. Frequently occurring morbidity features in the final evolved combinations were age>53, R03BA (glucocorticoid inhalants), and N03AX (other antiepileptics) in cohort 1; A10BA (biguanide or metformin) and N02BE (anilides) in cohort 2; N02AX (other opioids) and M04AA (preparations inhibiting uric acid production) in cohort 3; and G04CA (Alpha-adrenoreceptor antagonists) in cohort 4. CONCLUSIONS: When combined with other multimorbidity features, even less prevalent medical conditions show associations with the outcome. This study provides insights beyond COVID-19, demonstrating how repurposed administrative data can be adapted and contribute to enhanced risk assessment for vulnerable populations.


Subject(s)
COVID-19 , Hospitalization , Machine Learning , Multimorbidity , Humans , COVID-19/epidemiology , Italy/epidemiology , Male , Female , Aged , Hospitalization/statistics & numerical data , Middle Aged , Longitudinal Studies , Aged, 80 and over
13.
J Agric Food Chem ; 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39024463

ABSTRACT

(R)-3-Hydroxybutyric acid (R-3HB) is an important chiral chemical with extensive applications in the agricultural, food, and chemical industries. The synthesis of R-3HB by microbial fermentation is of interest due to its remarkable stereoselectivity and economy. However, the low production of R-3HB failed to meet the needs of large-scale industrial production. In this study, an engineered strain for the efficient biosynthesis of R-3HB was constructed through a three-pronged approach encompassing biosynthetic pathway optimization, engineering of NADPH regenerators, and central metabolism regulation. The engineered strain Q5081 produced 75.7 g/L R-3HB, with a productivity of 1.26 g/L/h and a yield of 0.34 g/g glucose in fed-batch fermentation, showing the highest reported titer and productivity of R-3HB to date. We also performed transcriptome sequencing and annotation to illustrate the mechanism underlying the enhanced R-3HB production. The systematic metabolic engineering by a three-pronged approach demonstrated the feasibility of improving the biosynthesis, and the engineered strain Q5081 has the potential for widespread applications in the industrial production of R-3HB.

14.
Sci Rep ; 14(1): 16623, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39026020

ABSTRACT

Under the background of engineering education professional certification, the Outcome-Based Education (OBE) education concept of "output-oriented" has been paid more and more attention. The traditional experimental teaching of programming course often focuses on the teaching of theoretical knowledge, and lacks the cultivation of students' practical ability and innovative spirit. Engineering education puts forward new requirements for the teaching mode of program design course. The experimental teaching of programming courses requires further reform and innovation to cultivate high-quality technical engineering talents with good social responsibility, teamwork ability, and innovative thinking ability. Guided by the theory of engineering education combined with the educational philosophy of Conceive-Design-Implement-Operate (CDIO) and OBE, this paper carried out the reform of experimental teaching of programming course among students majoring in computer science and technology and information security. This teaching reform aimed to better cultivate students' practical ability, innovation ability, and knowledge-integrated application ability, considering the course concept, course design, course implementation, and course operation, and exploring the practice of teaching process reconfiguration, teaching content organization, and teaching method integration. This multi-integration experimental teaching reform was found to fully mobilize students' learning enthusiasm, tap into students' potential, greatly improve students' comprehensive practical ability, effectively achieve course goals, and lay a solid foundation for subsequent professional course learning. This teaching mode has been practically applied in current experimental teaching and is widely recognized by students, providing a reference for improving teaching quality.

15.
Xenotransplantation ; 31(4): e12876, 2024.
Article in English | MEDLINE | ID: mdl-39031102

ABSTRACT

BACKGROUND: Long-term immunosuppressive maintenance therapy is necessary to prevent the rejection of xenografts. However, it is still unclear which oral immunosuppressant is most suitable for pig-to-human xenotransplantation . METHODS: A xenogeneic mixed lymphocyte reaction (MLR) system was established using peripheral blood mononuclear cells (PBMCs) isolated from wildtype (WT) or GTKO/CMAHKO/ß4GalNT2KO (TKO) pigs as stimulator cells and human PBMCs as responder cells. Various concentrations of tacrolimus (Tac), cyclosporine (CsA), or rapamycin (Rapa) were added to the MLR system as interventions. The inhibitory effects of the three immunosuppressants on the proliferation and cytokine production of human T cells were studied and compared. The inhibitory effect of anti-CD154 mAb alone or in combination with Tac/CsA/Rapa on xenoreactive MLR was also investigated. RESULTS: PBMCs from both WT and TKO pigs stimulated significant proliferation of human T cells. Tac had a strong inhibitory effect on human T-cell proliferation stimulated by pig PBMCs. CsA inhibited human T-cell proliferation in a typical dose-dependent manner. When Tac and CsA concentrations reached 5 and 200 ng/mL, respectively, the proliferation rates of CD3+/CD4+/CD8+ T cells were reduced almost to a negative level. Even at high concentrations, Rapa had only a moderate inhibitory effect on xenogeneic MLR. The inhibitory effects of these three immunosuppressants on xenogeneic T-cell responses were further confirmed by the detection of CD25 expression and supernatant cytokines (IL-2, IL-6, IFN-γ, TNF-α, IL-4, IL-10, and IL-17). Although anti-CD154 mAb monotherapy showed only moderate inhibitory effects on xenoreactive T-cell proliferation, low-dose anti-CD154 mAb combined with low-dose Tac, CSA, or Rapa could produce significant synergistic inhibitory effects. CONCLUSION: Tac is more efficient than CsA or Rapa in inhibiting xenogeneic T-cell responses in vitro. If used in combination with anti-CD154 mAb, all the three immunosuppressants can achieve satisfactory synergistic inhibitory effects.


Subject(s)
Cell Proliferation , Cyclosporine , Immunosuppressive Agents , Lymphocyte Culture Test, Mixed , Sirolimus , Tacrolimus , Transplantation, Heterologous , Animals , Sirolimus/pharmacology , Humans , Tacrolimus/pharmacology , Immunosuppressive Agents/pharmacology , Cyclosporine/pharmacology , Transplantation, Heterologous/methods , Swine , Cell Proliferation/drug effects , T-Lymphocytes/immunology , T-Lymphocytes/drug effects , Graft Rejection/immunology , Graft Rejection/prevention & control , Cytokines/metabolism , Cytokines/immunology , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/drug effects , Animals, Genetically Modified
16.
Stem Cell Rev Rep ; 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39028416

ABSTRACT

Bone defects from accidents, congenital conditions, and age-related diseases significantly impact quality of life. Recent advancements in bone tissue engineering (TE) involve biomaterial scaffolds, patient-derived cells, and bioactive agents, enabling functional bone regeneration. Stem cells, obtained from numerous sources including umbilical cord blood, adipose tissue, bone marrow, and dental pulp, hold immense potential in bone TE. Induced pluripotent stem cells and genetically modified stem cells can also be used. Proper manipulation of physical, chemical, and biological stimulation is crucial for their proliferation, maintenance, and differentiation. Stem cells contribute to osteogenesis, osteoinduction, angiogenesis, and mineralization, essential for bone regeneration. This review provides an overview of the latest developments in stem cell-based TE for repairing and regenerating defective bones.

17.
Methods Mol Biol ; 2819: 157-187, 2024.
Article in English | MEDLINE | ID: mdl-39028507

ABSTRACT

The development of novel DNA assembly methods in recent years has paved the way for the construction of synthetic replicons to be used for basic research and biotechnological applications. A learning-by-building approach can now answer questions about how chromosomes must be constructed to maintain genetic information. Here we describe an efficient pipeline for the design and assembly of synthetic, secondary chromosomes in Escherichia coli based on the popular modular cloning (MoClo) system.


Subject(s)
Escherichia coli , Synthetic Biology , Escherichia coli/genetics , Synthetic Biology/methods , Cloning, Molecular/methods , Genetic Engineering/methods , Replicon/genetics , Chromosomes, Bacterial/genetics , Plasmids/genetics , Chromosomes/genetics
18.
ACS Synth Biol ; 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39023319

ABSTRACT

Nicotinamide mononucleotide (NMN) serves as a precursor for NAD+ synthesis and has been shown to have positive effects on the human body. Previous research has predominantly focused on the nicotinamide phosphoribosyltransferase-mediated route (NadV-mediated route) for NMN biosynthesis. In this study, we have explored the de novo NMN biosynthesis route as an alternative pathway to enhance NMN production. Initially, we systematically engineered Escherichia coli to enhance its capacity for NMN synthesis and accumulation, resulting in a remarkable over 100-fold increase in NMN yield. Subsequently, we progressively enhanced the de novo NMN biosynthesis route to further augment NMN production. We screened and identified the crucial role of MazG in catalyzing the enzymatic cleavage of NAD+ to NMN. And the de novo NMN biosynthesis route was optimized and integrated with the NadV-mediated NMN biosynthetic pathways, leading to an intracellular concentration of 844.10 ± 17.40 µM NMN. Furthermore, the introduction of two transporters enhanced the uptake of NAM and the excretion of NMN, resulting in NMN production of 1293.73 ± 61.38 µM. Finally, by engineering an E. coli strain with optimized PRPP synthetase, we achieved the highest NMN production, reaching 3067.98 ± 27.25 µM after 24 h of fermentation at the shake flask level. In addition to constructing an efficient E. coli cell factory for NMN production, our findings provide new insights into understanding the NAD+ salvage pathway and its role in energy metabolism within E. coli.

19.
J Biomater Appl ; : 8853282241265059, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39023922

ABSTRACT

The temporomandibular joint (TMJ) disc is an essential protective but vulnerable fibrocartilage. Their high mechanical strength is vital in absorbing loads, reducing friction, and protecting the condylar surface. Many diseases can lead to the destruction or degeneration of the mechanical function of the TMJ disc. Unfortunately, conservative treatment is ineffective in restoring the defective mechanical properties of the discs. Tissue engineering has been investigated as a promising alternative treatment approach to approximate the properties of native tissue. However, it is difficult for tissue-engineered discs to obtain sufficient mechanical properties. Several approaches have been proposed to improve the mechanical properties of tissue-engineered constructs. In this review, we summarized the mechanical properties of native TMJ discs and discussed the current mechanical testing methods. We then summarized the current advances in improving the mechanical properties of TMJ disc tissue-engineered constructs. Moreover, existing challenges and outbreak directions are discussed. This review assists future research in better understanding the mechanical properties of both native and tissue-engineered TMJ discs. It provides new insights into future mechanical property enhancement for TMJ disc tissue engineering.

20.
ACS Appl Mater Interfaces ; 16(28): 37328-37337, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38954598

ABSTRACT

Slippery lubricant infused porous surfaces (SLIPSs) are promising bioinspired surfaces with self-healing and droplet wetting properties, among many others, that are desirable due to their range of applications. Recently, there have been many developments in the SLIPS field regarding the creation of textured surfaces and lubricant selection. However, there is a lack of knowledge regarding the method of lubricant infusion. In this study, we aim to fill this void by investigating different infusion methods that impose external forces on the lubricant. We developed our SLIPS by hot embossing nanostructures onto polypropylene by using molds that were laser micromachined. These textured surfaces were then infused with silicone oil using three different infusion methods: ultrasonication, vacuum, and hydrostatic pressure. We analyzed the wettability and slipperiness of the SLIPS by evaluating the critical tilt angle and comparing the sliding velocities of water droplets on each sample at a tilt angle of 20°. Additionally, the durability of the SLIPS was tested by dropping 50 successive water drops onto the samples and evaluating the droplet-surface interactions throughout. The sonicated infusion method yielded SLIPS that performed the best with a contact angle hysteresis of 13°, a critical tilt angle of 18.3°, a sliding velocity of 1.66 mm/s, and the least accumulation of droplets over time with use. These values are greatly improved when compared to the control sample where lubricant was simply dripped on, which resulted in a contact angle hysteresis of 20°, a critical tilt angle of 26.3°, and a sliding velocity of 0.23 mm/s. The sonicated and drip infusion methods were also compared with different materials (stainless steel) and different textures (microstructures). It was found that the improvement in slipperiness using the sonicated infusion method is prominent for nanoscale textures on both stainless steel and polypropylene. In this study, we discuss the challenges with oil depletion in SLIPS (cloaking and wetting ridges) and with the selection of contact angle measurement methods. While further investigation as to why certain applied forces during infusion yield better SLIPS is warranted, these forces greatly affect the outcome. This work suggests that researchers should consider using sonication or other methods of lubricant infusion that apply external forces as infusion techniques to yield better SLIPS on the nanoscale.

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