IntroductionTendon injuries represent an ongoing challenge in clinical practice due to poor regenerative capacity, structure, and biomechanical function recovery of ruptured tendons. This study is focused on the assessment of a novel strategy to repair ruptured Achilles tendons in a Nude rat model using stem cell-seeded biomaterial.MethodsSpecifically, we have used induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) overexpressing the early tendon marker Scleraxis (SCX, iMSCSCX+, iTenocytes) in combination with an elastic collagen scaffold. Achilles tendon defects in Nude rat models were created by isolating the tendon and excising 3 mm of the midsection. The Achilles tendon defects were then repaired with iTenocyte-seeded scaffolds, unseeded scaffolds, or suture only and compared to native Nude rat tendon tissue using gait analyses, biomechanical testing, histology, and immunohistochemistry.ResultsThe results show faster functional recovery of gait in iTenocyte-seeded scaffold group comparing to scaffold only and suture only groups. Both iTenocyte-seeded scaffold and scaffold only treatment groups had improved biomechanical properties when compared to suture only treatment group, however no statistically significant difference was found in comparing the cell seeding scaffold an scaffold only group in terms of biomechanical properties. Immunohistochemistry staining further demonstrated that iTenocytes successfully populated the collagen scaffolds and survived 9 weeks after implantation in vivo. Additionally, the repaired tissue of iTenocyte-treated injuries exhibited a more organized structure when compared to tendon defects that were repaired only with suturing or unseeded scaffolds.ConclusionWe suggest that iTenocyte-seeded DuRepair™ collagen scaffold can be used as potential treatment to regenerate the tendon tissue biomechanically and functionally.

ObjectiveTo compare the effect of syringe irrigation technique, passive ultrasonic activation technique, EDDY activation technique and Er,Cr,YSGG laser activation technique on smear layer removal in root canals in vitro.MethodsForty mandibular first premolars with single canal were collected from patients in Qingdao Stomatological Hospital affiliated to Qingdao University. After root canal preparation with ProTaper Universal to F3, they were randomly divided into four groups (n = 10) according to different activation irrigations for the final washing: syringe irrigation (SI), passive ultrasonic activation (PU), EDDY activation (EDDY) and Er,Cr,YSGG laser activation (YSGG). Finally, all the crowns of them were cut off and the root length was trimmed to 15 mm. The roots were split longitudinally and observed with scanning electron microscope (SEM) for assessment of smear layer removal in different parts of the root canal.ResultsAll groups showed similar effects for cleaning the root canals in the coronal thirds (P > 0.05). For cleaning the root canals in the middle thirds, PU group, EDDY group and YSGG group showed similar effects, (P> 0.05). They were more effective than SI group (P < 0.05). For cleaning the root canals in the apical thirds, PU group and EDDY group showed similar effects (P> 0.05). They were more effective than SI group (P < 0.05). YSGG group was more effective than other groups (P < 0.05).ConclusionEr,Cr,YSGG laser activation technique can remove smear layer of root canals effectively. The cleaning effect of the passive ultrasonic activation technique, EDDY activation technique is better than that of syringe irrigation technique.

Over recent years, studies on microbiota research and synthetic biology have explored novel approaches microbial manipulation for therapeutic purposes. However, fragmented information is available on this aspect with key insights scattered across various disciplines such as molecular biology, genetics, bioengineering, and medicine. This review aims to the transformative potential of synthetic biology in advancing microbiome research and therapies, with significant implications for healthcare, agriculture, and environmental sustainability. By merging computer science, engineering, and biology, synthetic biology allows for precise design and modification of biological systems via cutting edge technologies like CRISPR/Cas9 gene editing, metabolic engineering, and synthetic oligonucleotide synthesis, thus paving the way for targeted treatments such as personalized probiotics and engineered microorganisms. The review will also highlight the vital role of gut microbiota in disorders caused by its dysbiosis and suggesting microbiota-based therapies and innovations such as biosensors for real-time gut health monitoring, non-invasive diagnostic tools, and automated bio foundries for better outcomes. Moreover, challenges including genetic stability, environmental safety, and robust regulatory frameworks will be discussed to understand the importance of ongoing research to ensure safe and effective microbiome interventions.

IntroductionH. pylori (Helicobacter pylori) infection represents a significant global health concern, exacerbated by the emergence of drug-resistant strains resulting from conventional antibiotic treatments. Consequently, the development of vaccines with both preventive and therapeutic properties has become crucial in addressing H. pylori infections. The H. pylori adhesin protein HpaA has demonstrated strong immunogenicity across various adjuvants and dosage forms, positioning it as a key candidate antigen for recombinant subunit vaccines against H. pylori. Optimizing fermentation culture conditions is an effective strategy to enhance product yield and lower production costs. However, to date, there has been no systematic investigation into methods for improving the fermentation yield of HpaA. Enhancing the fermentation medium to increase HpaA yield holds significant potential for application and economic benefits in the prevention and detection of H. pylori infection.MethodsTo achieve a stable and high-yielding H. pylori vaccine antigen HpaA, this study constructed recombinant Escherichia coli expressing HpaA. The impact of fermentation medium components on the rHpaA yield was assessed using a one-factor-at-a-time approach alongside Plackett–Burman factorial experiments. Optimal conditions were effectively identified through response surface methodology (RSM) and artificial neural network (ANN) statistical computational models. The antigenicity and immunogenicity of the purified rHpaA were validated through immunization of mice, followed by Western Blot analysis and serum IgG ELISA quantification.ResultsGlucose, yeast extract, yeast peptone, NH4Cl and CaCl2 all contributed to the production of rHpaA, with glucose, yeast extract, and NH4Cl demonstrating particularly significant effects. The artificial neural network linked genetic algorithm (ANN-GA) model exhibited superior predictive accuracy, achieving a rHpaA yield of 0.61 g/L, which represents a 93.2% increase compared to the initial medium. Animal immunization experiments confirmed that rHpaA possesses good antigenicity and immunogenicity.DiscussionThis study pioneers the statistical optimization of culture media to enhance rHpaA production, thereby supporting its large-scale application in H. pylori vaccines. Additionally, it highlights the advantages of the ANN-GA approach in bioprocess optimization.

IntroductionThe fermentation process plays an important role in enhancing the quality of cigar tobacco leaves. Through fermentation, microbial metabolism can degrade aromatic precursors and macromolecules, which increases the content of aroma compounds and reduces irritancy of tobacco leaves.MethodsTo further enhance the fermentation effect of cigar tobacco leaves, a Rhodotorula strain (Rh3), capable of producing carotenoids and improving fermentation quality, was isolated from cigar tobacco leaves. Subsequent genetic engineering techniques introduced the carotenoid cleavage dioxygenase 1 (CCD1) gene into the isolated Rh3.ResultsThe modified Rh3 exhibits a significant increase in carotenoid degradation products compared with the original Rh3 in culture medium (from 0.29 μg/mg to 15 μg/mg). Subsequent cigar tobacco leaf fermentation experiments revealed that the modified Rh3 produced 65.9% more carotenoid degradation products compared to the control group, outperforming the original strain, which achieved a 41.4% increase. Furthermore, the modified strain preserves its ability to improve the intrinsic chemical composition of cigar tobacco leaves.DiscussionWe show here that modified Rh3 can increase the content of carotenoid degradation products, thereby enhancing the fermentation effect of cigar tobacco leaves. This study presents a beneficial exploration to improve the quality of cigar tobacco leaves for future use and offers a promising strategy for producing flavor compounds from discarded tobacco leaves.

The endometrium plays a fundamental role in the reproductive system yet many etiologies of infertility-related endometrial diseases such as endometriosis, adenomyosis, Asherman’s syndrome or endometrial cancer remain unknown. There are currently no treatments that minimize the effects of this devastating disorder. Appropriate model systems that closely mimic the architecture and function of the endometrium in healthy and pathological states are needed to understand the underlying molecular pathways and develop novel or more effective treatments. This review summarizes the key milestones of in vitro culture models of the human endometrium throughout history, as well as the applications of advanced bioengineering techniques in the modelling of both healthy and pathological endometrium. Opportunities for future approaches are also discussed.