Transglutaminase in Foods and Biotechnology

Application of extracellular matrix cross-linked by microbial transglutaminase to promote wound healing

One primary focus of skin tissue engineering has been the creation of innovative biomaterials to facilitate rapid wound healing. Extracellular matrix (ECM), an essential biofunctional substance, has recently been discovered to play a crucial role in wound healing. Consequently, we endeavored to decellularize ECM from pig achilles tendon and refine its mechanical and biological properties through modification by utilizing cross-linking agents. Glutaraldehyde (GA), 1-ethyl-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS), double aldol starch (DAS), and microbial transglutaminase (MTG) were utilized to produce crosslinked ECM variants (GA-ECM, EDC/NHS-ECM, DAS-ECM, and MTG-ECM). Comprehensive assessments were conducted to evaluate the physical properties, biocompatibility, and wound healing efficacy of each material. The results indicated that MTG-ECM exhibited superior tensile strength, excellent hydrophilicity, minimal cytotoxicity, and the best pro-healing impact among the four modified scaffolds. Staining analysis of tissue sections further revealed that MTG-ECM impeded the transition from type III collagen to type I collagen in the wound area, potentially reducing the development of wound scar. Therefore, MTG-ECM is expected to be a potential pro-skin repair scaffold material to prevent scar formation.

Investigating the Effect of Processing and Material Parameters of Alginate Dialdehyde-Gelatin (ADA-GEL)-Based Hydrogels on Stiffness by XGB Machine Learning Model

To address the limitations of alginate and gelatin as separate hydrogels, partially oxidized alginate, alginate dialdehyde (ADA), is usually combined with gelatin to prepare ADA-GEL hydrogels. These hydrogels offer tunable properties, controllable degradation, and suitable stiffness for 3D bioprinting and tissue engineering applications. Several processing variables affect the final properties of the hydrogel, including degree of oxidation, gelatin content and type of crosslinking agent. In addition, in 3D-printed structures, pore size and the possible addition of a filler to make a hydrogel composite also affect the final physical and biological properties. This study utilized datasets from 13 research papers, encompassing 33 unique combinations of ADA concentration, gelatin concentration, CaCl2 and microbial transglutaminase (mTG) concentrations (as crosslinkers), pore size, bioactive glass (BG) filler content, and one identified target property of the hydrogels, stiffness, utilizing the Extreme Boost (XGB) machine learning algorithm to create a predictive model for understanding the combined influence of these parameters on hydrogel stiffness. The stiffness of ADA-GEL hydrogels is notably affected by the ADA to GEL ratio, and higher gelatin content for different ADA gel concentrations weakens the scaffold, likely due to the presence of unbound gelatin. Pore size and the inclusion of a BG particulate filler also have a significant impact on stiffness; smaller pore sizes and higher BG content lead to increased stiffness. The optimization of ADA-GEL composition and the inclusion of BG fillers are key determinants to tailor the stiffness of these 3D printed hydrogels, as found by the analysis of the available data.

Efficacy of enzyme‑induced collagen crosslinking on porcine cornea

The purpose of the present study was to investigate the effect of a new crosslinking (CXL) method, induced by enzymes, on porcine corneas. Corneal strip (10x3 mm) pairs obtained from 60 fresh porcine eyes were harvested and divided into four groups, Groups A-D. Each pair of corneal strips was incised from the central part of the same cornea; one was incubated in transglutaminase (Tgase) solution (microbial Tgase 2 produced by tissue engineering) and the other remained untreated as a control. CXL strips of Groups A-D were incubated with 2, 1, 0.5 and 0.25 U/ml Tgase solution, respectively at 37˚C for 30 min. After that, tensile strain measurements were performed for all strips. One cornea from each group was chosen randomly for hematoxylin and eosin, and Masson staining to identify histological morphology changes. The elastic modulus of treated corneas of Groups A-D were 6.56±2.93, 4.72±1.29, 5.24±2.13 and 3.48±1.60 MPa (mean ± SD), respectively at a strain of 20%, and had a 66, 43, 36 and -6% increase compared with those of their control strips. Compared with the control strips, the elastic modulus of the treated strips significantly increased in Groups A-C. The central corneal thickness of the treated corneas in Groups A-D were 1.54±0.14, 1.41±0.15, 1.47±0.11 and 1.43±0.13 µm, respectively; however, there was not a statistically significant difference compared with the control group. No reduction in corneal transparency was observed, and no obvious abnormalities were found in corneal morphology. CXL mediated by enzymes can lead to a notable enhancement in the biomechanical characteristics of the cornea while maintaining its structural integrity. Enzyme-induced CXL could be a new generation CXL method for strengthening the cornea.

The Potential Harmful Effects of Genetically Engineered Microorganisms (GEMs) on the Intestinal Microbiome and Public Health

Gut luminal dysbiosis and pathobiosis result in compositional and biodiversified alterations in the microbial and host co-metabolites. The primary mechanism of bacterial evolution is horizontal gene transfer (HGT), and the acquisition of new traits can be achieved through the exchange of mobile genetic elements (MGEs). Introducing genetically engineered microbes (GEMs) might break the harmonized balance in the intestinal compartment. The present objectives are: 1. To reveal the role played by the GEMs' horizontal gene transfers in changing the landscape of the enteric microbiome eubiosis 2. To expand on the potential detrimental effects of those changes on the human genome and health. A search of articles published in PubMed/MEDLINE, EMBASE, and Scielo from 2000 to August 2023 using appropriate MeSH entry terms was performed. The GEMs' horizontal gene exchanges might induce multiple human diseases. The new GEMs can change the long-term natural evolution of the enteric pro- or eukaryotic cell inhabitants. The worldwide regulatory authority's safety control of GEMs is not enough to protect public health. Viability, biocontainment, and many other aspects are only partially controlled and harmful consequences for public health should be avoided. It is important to remember that prevention is the most cost-effective strategy and primum non nocere should be the focus.