Formulation improvement of a concentrated enzyme detergent for high-speed rail trains through life cycle assessment methodology.

High-speed rail has been operating in more than 25 countries (mainly in Asia, Europe and North America), and has become an important part of global economic development. However, the cleaning and maintenance of high-speed rail is a comprehensive task, which may easily cause environmental pollution. This study aims to analyze and improve the sustainability of the formulation and production process of a concentrated complex enzyme detergent used as the maintenance agent for high-speed trains via the life cycle assessment (LCA) method. The eFootprint software system with built-in China, European and Swiss Ecoinvent databases was used to establish the LCA model with the system boundary being from cradle to gate. The LCA model showed that the production of 1 kg of concentrated detergent generates the global warming potential of 2.53 kg CO2 eq, and other environmental emissions including acidification potential of 0.01 kg SO2 eq, eutrophication potential of 3.76E-03 kg PO43-eq, inhalable inorganic matter of 3.17E-03 kg PM2.5 eq, ozone depletion potential of 5.3E-06 kg CFC-11 eq, photochemical ozone formation potential of 3.44E-03 kg NMVOC eq, primary energy demand of 3.17 MJ, abiotic depletion potential of 4.97E-6 kg antimony eq, and water use of 0.84 kg. LCA results are not strongly dependent to the assumptions of the research, and the uncertainties of LCA results are between 8 and 16%, which is mainly due to the regional differences in technology sources, the year of technical data collection, and the representativeness of technology collection companies. Carbon footprint analysis showed that the production processes of enzyme stabilizer (glycerol) and surfactants contributed the most, while changes in power consumption during production and transportation distance of raw materials had limited effect on total carbon emissions. Therefore, the formulation of the concentrated complex enzymatic detergent was improved based on the LCA results. The new formulations with less enzyme stabilizer showed similar detergency to the original formulation. The new formulations could reduce carbon emissions by 5,500-9,200 tons per year and save between $4.4 and $7.4 million in annual production of 10,000 tons. Supplementary Information: The online version contains supplementary material available at 10.1007/s10668-023-03122-2.

GM-Pep: A High Efficiency Strategy to De Novo Design Functional Peptide Sequences.

Although peptides are regarded as ideal therapeutic agents, only a small proportion of the marketed drugs are peptides. In the past decade, pharmacists have paid great attention to the development of peptide therapeutics. Except a few approved chemically/rationally designed peptides, most attempts failed due to unsatisfactory efficacy or safety. Luckily, computation methods, such as artificial intelligence, have been utilized to accelerate the discovery of therapeutic peptides by predicting the activity, toxicity, and absorption, distribution, metabolism, and excretion of polypeptides. Usually, a specific biological activity of a peptide could be accurately determined by an interest-oriented binary classification constructed of a positive set and another un-experimentally validated negative set regardless of other characteristics, which suggests that it could be challenging to realize the comprehensive evaluation of the research object in the early stage of drug research and development. Herein, we proposed an integrated method (GM-Pep) that contained a conditional variational autoencoder model (CVAE) and a positive sample training multiclassifier (Deep-Multiclassifier) to effectively generate a single bioactive peptide sequence without toxicity and referential side effects. The results showed that our Deep-Multiclassifier model gave a sequence accuracy of up to 96.41% [toxicity (94.48%), antifungal (96.58%), antihypertensive (97.18%), and antibacterial (96.91%), respectively]. The properties of Deep-Multiclassifier and CVAE were validated through 12 first synthesized antibacterial peptides or compared to random peptides. The source code and data sets are available at https://github.com/TimothyChen225/GM-Pep.

The Antimicrobial, Hemostatic, and Anti-Adhesion Effects of a Peptide Hydrogel Constructed by the All-d-Enantiomer of Antimicrobial Peptide Jelleine-1.

Peptide hydrogels are believed to be potential biomaterials with wide application in the biomedical field because of their good biocompatibility, injectability, and 3D printability. Most of the previously reported polypeptide hydrogels are composed of l-peptides, while the hydrogels formed by self-assembly of d-peptides are rarely reported. Herein, a peptide hydrogel constructed by D-J-1, which is the all-d-enantiomer of antimicrobial peptide Jelleine-1 (J-1) is reported. Field emission scanning electron microscope (FE-SEM) and rheologic study are performed to characterize the hydrogel. Antimicrobial, hemostatic, and anti-adhesion studies are carried out to evaluate its biofunction. The results show that D-J-1 hydrogel is formed by self-assembly and cross-linking driven by hydrogen bonding, hydrophobic interaction, and π-π stacking force of aromatic ring in the structure of D-J-1. It exhibits promising antimicrobial activity, hemostatic activity, and anti-adhesion efficiency in a rat sidewall defect-cecum abrasion model. In addition, it also exhibits good biocompatibility. Notably, D-J-1 hydrogel shows improved in vitro and in vivo stability when compared with its l-enantiomer J-1 hydrogel. Therefore, the present study will provide new insight into the application of d-peptide hydrogel, and provides a new peptide hydrogel with antibacterial, hemostatic, and anti-adhesion efficacy for clinical use.

An Injectable Peptide Hydrogel Constructed of Natural Antimicrobial Peptide J-1 and ADP Shows Anti-Infection, Hemostasis, and Antiadhesion Efficacy.

Postoperative adhesion is a common complication of abdominal surgery, which always has many adverse effects in patients. At present, there is still a lack of effective treatment measures and materials to prevent adhesion in the clinics. Herein, we report the potential use of J-1-ADP hydrogel formed by natural antimicrobial peptide jelleine-1 (J-1) self-assembling in adenosine diphosphate (ADP) sodium solution to prevent postsurgery adhesion formation. J-1-ADP hydrogel was found to have good antimicrobial activity against the bacteria and fungi tested and can be used to prevent tissue infection, which was thought to be one of the incitements of adhesion. Due to ADP being a platelet-activating factor, J-1-ADP hydrogel showed significant hemostatic activity in vitro verified by whole blood coagulation, plasma coagulation, platelet activation, and platelet adhesion assays. Further, it showed potent hemostatic activity in a mouse liver hemorrhage model. Bleeding was believed to be a cause of the formation of postsurgery adhesion. J-1-ADP hydrogel had a significant antiadhesion effect in a rat side wall defect-cecum abrasion model. In addition, it had good biocompatibility and degradation properties. So the present study may provide an alternative strategy for designing antimicrobial peptide hydrogel material to prevent postoperative adhesion formation in the clinic.

A carrier-free, dual-functional hydrogel constructed of antimicrobial peptide Jelleine-1 and 8Br-cAMP for MRSA infected diabetic wound healing.

Bacterial infection and local growth factor deficiency are two of the major causes of the nonunion of diabetic wounds. Antimicrobial peptides (AMPs) are believed to be alternatives to antibiotics against drug-resistant bacterial infections. 8-Bromoadenosine-3', 5'-cyclic monophosphate (8Br-cAMP) can promote cells to secrete growth factors and accelerate cell proliferation. In the present study, we constructed a hydrogel with antimicrobial peptide Jelleine-1 (J-1) and 8Br-cAMP without any other gelators or chemical crosslinking agents. The hydrogel was proved to promote the secretion of transforming growth factor-ß (TGF-ß) and vascular endothelial growth factor-A (VEGFA) in vitro and in vivo. Notably, it exhibited potent potential for wound healing in methicillin-resistant Staphylococcus aureus (MRSA) infected diabetic wounds. This would be attributed to the retention of AMPs and 8Br-cAMP on the wound site by the hydrogel system. In addition, the hydrogel also showed good biodegradability, proper stability, and good biocompatibility. This study would shed light on the development of carrier-free and multifunctional hydrogel for wound healing. STATEMENT OF SIGNIFICANCE: Bacterial infection and local growth factor deficiency are two of the major causes for the nonunion of refractory wounds. In the present study, an injectable carrier-free hydrogel was constructed of a natural antimicrobial peptide J-1 and 8Br-cAMP by eco-friendly physical crosslinking without any other gelators or chemical crosslinking agents. The hydrogel exhibited excellent antimicrobial activity and was proved to promote the secretion of TGF-ß and VEGFA in vitro and in vivo. Correspondingly, the hydrogel showed exceptionally wound healing effects in the wound model of MRSA infected diabetic rats. This study would provide an alternative strategy or a potential hydrogel dressing for the treatment of chronic or refractory wounds.

Catalytic Asymmetric Construction of Tertiary Carbon Centers Featuring an α-Difluoromethyl Group with CF2H-CH2-NH2 as the "Building Block".

We report here for the first time a novel difluoromethylated ketimine building block condensed by thioisatin and difluoroethylamine, offering efficient access to a broad range of enantioenriched products bearing difluoroethylamine units (27 examples, ≤98% yield, >99% ee) in the presence of quinine-derived squaramide. Further transformation of the intermediate would generate a variety of versatile functional blocks like α-difluoromethyl amines, ß-amino acid, and ß-diamine with retention of the enantiomeric excess at the difluoromethyl-bound carbon.

An optimized analog of antimicrobial peptide Jelleine-1 shows enhanced antimicrobial activity against multidrug resistant P. aeruginosa and negligible toxicity in vitro and in vivo.

Due to the threat of escalating multi-drug resistant gram-negative bacteria to human health and life, novel antimicrobial agents against gram-negative pathogens are urgently needed. As antimicrobial peptides are not prone to induce bacteria resistance, they are believed to be one kind of promising class of potential antimicrobial agent candidates to combat multi-drug resistant bacteria for long-term use. Jelleine-1, first isolated from the royal jelly of honeybees, is a typical amphiphilic antimicrobial peptide and shows broad antimicrobial spectrum and negligible toxicity. To promote its antimicrobial activity and extend its potential of clinical use against multi-drug resistant gram-negative bacteria, novel analogs of jelleine-1 were designed, synthesized and their antimicrobial functions and toxicity were examined in this study. Our results showed that fine tuning of the cationic charge, polarity, and basicity of the sequence through amino acids substitution at position 3, 5, 7 and maintaining position 1, 4, 6, 8 unchanged could improve the bioactivity of jelleine-1 significantly. Meanwhile, we also found that the substitution of phenylalanine by tryptophan also could improve the antimicrobial activity of jelleine-1. Among all the analogs, analog 15, which is enriched in arginine and leucine, showed the most potent antimicrobial activity against both gram-negative and gram-positive bacteria, especially to multi-drug resistant Pseudomonas aeruginosa in vivo and in vitro. In addition, analog 15 also showed potent inhibition of the formation of multi-drug resistant P. aeruginosa biofilm and negligible toxicity, which was certified by MTT, hemolysis, blood assay, and biochemical analysis.