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Journal of the Mechanical Behavior of... Sep 2023The aim was to quantify effects of polylysine (PLS, 2 or 5 wt%) and monocalcium phosphate (MCP, 4 or 8 wt%) on properties of dental composites.
OBJECTIVES
The aim was to quantify effects of polylysine (PLS, 2 or 5 wt%) and monocalcium phosphate (MCP, 4 or 8 wt%) on properties of dental composites.
METHODS
Light-activated, lower surface polymerisation kinetics versus sample depth (1-4 mm) of 4 formulations were quantified using ATR-FTIR. Water sorption and solubility (at 1 week) were assessed following ISO/4049. PLS release (over 1 month) and biaxial flexural strength (over 6 months) of fully-cured, water-immersed, 1 mm thick discs were determined. Surface mineral precipitation, following immersion in simulated body fluid (SBF), was assessed by SEM. Z250 was used as a conventional composite comparator.
RESULTS
With 40s light exposure, increasing depth (from 1 to 4 mm) led to enhanced delay before polymerisation (from 3 to 17s) and decreased final conversion (72-66%) irrespective of PLS and MCP level. Increasing PLS and MCP raised solubility (4-13 μg/mm). Water sorption (between 32 and 55 μg/mm) and final PLS release (8-13% of disc content) were raised primarily by increasing PLS. Higher PLS also reduced strength. Strength reached minimum values (69-94 MPa) at 3 months. Surface mineral deposition was enhanced by increased MCP. For Z250, polymerisation delays (3-6s) and final conversions (55-54%) at 1-4 mm depth, solubility (0 μg/mm), water sorption (16 μg/mm) and strength (180 MPa) were all significantly different.
CONCLUSION
Delay time increased whilst final conversion decreased with thicker samples. Higher PLS enhances its percentage release, but lower level is required to keep water sorption, solubility and mechanical properties within ISO 4049 recommendations. Doubling MCP raises solubility and enhances minerals reprecipitation with minimal mechanical property compromise.
Topics: Polylysine; Composite Resins; Materials Testing; Solubility; Phosphates; Water; Surface Properties; Dental Materials
PubMed: 37499523
DOI: 10.1016/j.jmbbm.2023.106039 -
Revista Alergia Mexico (Tecamachalco,... Sep 2023To confirm the presence of allergy to penicillin and amoxicillin by in vivo exposure tests in patients with a history of immediate reaction to these drugs. Methods:... (Observational Study)
Observational Study
OBJECTIVES
To confirm the presence of allergy to penicillin and amoxicillin by in vivo exposure tests in patients with a history of immediate reaction to these drugs. Methods: Observational, cross-sectional, descriptive and prolective study. Patients between 12 and 60 years old with a history of immediate reaction after administration of penicillin and/or amoxicillin were included. Skin prick and intradermal tests were performed with benzylpenicilloyl polylysine and penicillin G, as well as oral challenge with amoxicillin.
RESULTS
Ten female and 3 male patients were included. The mean age was 39 years. In 84.6% of the cases the last adverse drug reaction occurred 10 years ago and in all cases it manifested with urticaria. Allergy to penicillin was corroborated in only 38.4% of cases. The most frequent adverse reaction after in vivo exposure tests was pruritus in 23%.
CONCLUSIONS
Patients with suspected penicillin allergy should be evaluated by in vivo exposure testing with major and minor determinants to corroborate or rule out allergic reactions and improve treatment conditions.
Topics: Humans; Male; Female; Adult; Child; Adolescent; Young Adult; Middle Aged; Cross-Sectional Studies; Skin Tests; Penicillins; Amoxicillin; Drug Hypersensitivity; Urticaria; Anti-Bacterial Agents
PubMed: 37933932
DOI: 10.29262/ram.v70i3.1261 -
Polymers Nov 2023The aim of this investigation was to scrutinize the effects of a thermal treatment on the electrostatic complex formed between gum arabic (GA) and ε-polylysine (ε-PL),...
The aim of this investigation was to scrutinize the effects of a thermal treatment on the electrostatic complex formed between gum arabic (GA) and ε-polylysine (ε-PL), with the goal of improving the antibacterial properties and reducing the hygroscopicity of ε-PL. The heated complex with a ratio of 1:4 exhibited an encapsulation efficiency of 93.3%. Additionally, it had an average particle size of 350.3 nm, a polydispersity index of 0.255, and a zeta potential of 18.9 mV. The formation of the electrostatic complex between GA and ε-PL was confirmed through multispectral analysis, which demonstrated the participation of hydrogen bonding and hydrophobic and electrostatic interactions, as well as the enhanced effect of heat treatment on these forces within the complex. The complex displayed a core-shell structure, with a regular distribution and a shape that was approximately spherical, as observed in the transmission electron microscopy images. Additionally, the heated GA-ε-PL electrostatic composite exhibited favorable antibacterial effects on Salmonella enterica and Listeria monocytogenes, with reduced minimum inhibitory concentrations (15.6 μg/mL and 62.5 μg/mL, respectively) and minimum bactericidal concentrations (31.3 μg/mL and 156.3 μg/mL, respectively) compared to free ε-PL or the unheated electrostatic composite. Moreover, the moisture absorption of ε-PL reduced from 92.6% to 15.0% in just 48 h after being incorporated with GA and subsequently subjected to heat. This research showed a way to improve the antibacterial efficiency and antihygroscopicity of ε-PL, reducing its application limitations as an antimicrobial substance to some extent.
PubMed: 38231920
DOI: 10.3390/polym15234517 -
Food Science & Nutrition Mar 2024In order to evaluate the effects of chitosan, ε-polylysine, and collagen on the preservation properties of refrigerated , samples were tested with different treatments...
In order to evaluate the effects of chitosan, ε-polylysine, and collagen on the preservation properties of refrigerated , samples were tested with different treatments for 10 days, namely chitosan, ε-polylysine and collagen (CH + ε-PL + CA), chitosan and ε-polylysine (CH + ε-PL), chitosan and collagen (CH + CA), ε-polylysine and collagen (ε-PL + CA), and the uncoated sample (CK). The results demonstrated that the bio-coating exhibited better preservation effects. The CH + ε-PL + CA, CH + ε-PL, CH + CA, ε-PL + CA treatments could significantly inhibit bacterial growth and retard the increase of total volatile base nitrogen (TVB-N), 2-thiobarbituric acid (TBA), K-value, and total viable counts (TVC) in fillets. The pH of all samples decreased and reached its lowest value on day 6, then increased significantly at the end of the experiment ( < .05). Water-holding capacity (WHC) of all the groups decreased continuously throughout storage, and CK reached 66.03% on day 6, which is significantly lower than CH + ε-PL + CA, CH + ε-PL, CH + CA, and ε-PL + CA ( < .05). On the contrary, the sensory scores of CH + ε-PL + CA, CH + ε-PL, CH + CA, and ε-PL + CA were significantly higher than the control, and the score of CH + ε-PL + CA ( < .05) was the best among all the groups. In terms of texture, CH + PL + CA also showed less cell shrinkage and tighter muscle fiber arrangement compared to other treatments. To sum up, the CH + PL + CA bio-coating proved to be a promising method for maintaining the storage quality of under refrigerated storage conditions.
PubMed: 38455186
DOI: 10.1002/fsn3.3916 -
International Journal of Biological... Mar 2024ε-Poly-l-lysine (ε-PL) is a natural homo-poly(amino acid) which can be produced by microorganisms. With the advantages in broad-spectrum antimicrobial activity,... (Review)
Review
ε-Poly-l-lysine (ε-PL) is a natural homo-poly(amino acid) which can be produced by microorganisms. With the advantages in broad-spectrum antimicrobial activity, biodegradability, and biocompatibility, ε-PL has been widely used as a preservative in the food industry. Different molecular architectures endow ε-PL and ε-PL-based materials with versatile applications. However, the microbial synthesis of ε-PL is currently limited by low efficiencies in genetic engineering and molecular architecture modification. This review presents recent advances in ε-PL production and molecular architecture modification of microbial ε-PL, with a focus on the current challenges and solutions for the improvement of the productivity and diversity of ε-PL. In addition, we highlight recent examples where ε-PL has been applied to expand the versability of edible films and nanoparticles in various applications. Commercial production and the challenges and future research directions in ε-PL biosynthesis are also discussed. Currently, although the main use of ε-PL is as a food preservative, ε-PL and ε-PL-based polymers have shown excellent application potential in biomedical fields. With the development of synthetic biology, the design and synthesis of ε-PL with a customized molecular architecture are possible in the near future. ε-PL-based polymers with specific functions will be a new trend in biopolymer manufacturing.
Topics: Polylysine; Streptomyces; Fermentation; Amino Acids; Polymers
PubMed: 38262828
DOI: 10.1016/j.ijbiomac.2024.129513 -
Journal of Food Protection Jul 2023The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP),...
The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP), ε-polylysine (ε-PL), and corona discharge plasma combined with ε-polylysine (CDP plus ε-PL). The results showed that the combined treatment of CDP and ε-PL exhibited significant antibacterial effects. The total number of colonies of S. liquefaciens dropped by 0.49 log CFU/mL following 4 min of CDP treatment, 4MIC ε-PL treatment for 6 h alone decreased the amounts of colonies by 2.11 log CFU/mL, and 6 h of treatment with 4MIC ε-PL after the bacterium was treated with CDP could decrease the number of colonies by 6.77 log CFU/mL. Scanning electron microscopy images showed that the combined treatment of CDP and ε-PL caused the most serious damage to the cell morphology. Electrical conductivity, nucleic acid, and PI staining indicated that the combined treatment dramatically enhanced the permeability of the cell membrane. In addition, the combined treatment led to a significant decrease in SOD and POD enzyme activities in S. liquefaciens, which prevented energy metabolism. Finally, the determination of free and intracellular ε-PL concentrations confirmed that the treatment of CDP could cause the bacteria to bind more ε-PL and exert more significant bacterial inhibition. Therefore, CDP and ε-PL had a synergistic effect in the inhibition of S. liquefaciens.
Topics: Polylysine; Serratia liquefaciens; Anti-Bacterial Agents; Cell Membrane; Microscopy, Electron, Scanning
PubMed: 37295216
DOI: 10.1016/j.jfp.2023.100078 -
ACS Applied Materials & Interfaces Oct 2023The choice of the antimicrobial agent and finishing process is very important for the activity, durability, and safety of antimicrobial fabrics. Here, a novel...
The choice of the antimicrobial agent and finishing process is very important for the activity, durability, and safety of antimicrobial fabrics. Here, a novel antimicrobial cotton fabric (HPL-CF) was constructed by covalently bonding an antimicrobial agent, hyperbranched polylysine (HPL), onto the surface of a cotton fabric (CF) pretreated with a silane coupling agent, 3-chloropropyltrimethoxysilane (CPTMS). The multiple amino groups contained in the periphery of HPL make it possible to react with the CF to form multiple bonds, which is beneficial to improve the durability and safety of HPL-CFs. The obtained HPL-CFs exhibited excellent antimicrobial activities against (, Gram-negative bacteria), (, Gram-positive bacteria), and (, fungi) even when the CF was treated with HPL solution at the concentration of 0.5 wt %. HPL-CFs maintained 98, >99, and >99% of antimicrobial ratios for , , and , respectively, after 50 equiv of domestic laundering cycles, surpassing the requirements of the AAA class. The halo method, cell compatibility, and skin irritation assays all prove the fine safety of HPL-CFs. This work demonstrates the great advantages of applying HPL in the antimicrobial finishing of fabrics.
Topics: Polylysine; Cotton Fiber; Escherichia coli; Staphylococcus aureus; Metal Nanoparticles; Anti-Infective Agents; Candida albicans; Anti-Bacterial Agents
PubMed: 37792694
DOI: 10.1021/acsami.3c10587 -
Biomaterials Science Nov 2023Invasive fungal infections pose a crucial threat to public health and are an under-recognized component of antimicrobial resistance, which is an emerging crisis...
Invasive fungal infections pose a crucial threat to public health and are an under-recognized component of antimicrobial resistance, which is an emerging crisis worldwide. Here we designed and synthesized a panel of multi-arm ε-polylysines (ε-mPLs, R-K) with a precise number of = 3-6 arms of ε-oligo(L-lysine)s and a precise arm length of = 3-7 ε-lysine residues. ε-mPLs have good biocompatibility and exhibited broad-spectrum antifungal activities towards , and species, and their antifungal activities increased with residue arm length. Among these ε-mPLs, 3R-K7 showed high antifungal activity against with a MIC value of as low as 24 μg mL (only 1/16th that of ε-PL) and also exhibited similar antifungal activity towards the clinically isolated multi-drug resistant (MDR) strain. Furthermore, 3R-K7 could inhibit the formation of biofilms and kill the cells within mature biofilms. Mechanistic studies proved that 3R-K7 killed fungal cells by entering the cells to generate reactive oxygen species (ROS) and induce cell apoptosis. An study showed that 3R-K7 significantly increased the survival rate of mice in a systemic murine candidiasis model, demonstrating that ε-mPL has great potential as a new antifungal agent.
Topics: Animals; Mice; Antifungal Agents; Candida; Polylysine; Candidiasis; Candida albicans; Microbial Sensitivity Tests; Biofilms
PubMed: 37823351
DOI: 10.1039/d3bm01233f -
Carbohydrate Polymers Jun 2024Large-pore hydrogels are better suited to meet the management needs of nutrient transportation and gas exchange between infected burn wounds and normal tissues. However,...
Large-pore hydrogels are better suited to meet the management needs of nutrient transportation and gas exchange between infected burn wounds and normal tissues. However, better construction strategies are required to balance the pore size and mechanical strength of hydrogels to construct a faster substance/gas interaction medium between tissues. Herein, we developed spongy large pore size hydrogel (CS-TA@Lys) with good mechanical properties using a simple ice crystal-assisted method based on chitosan (CS), incorporating tannic acid (TA) and ε-polylysine (Lys). A large-pore and mechanically robust hydrogel medium was constructed based on hydrogen bonding between CS molecules. On this basis, a pro-restorative functional platform with antioxidation and pro-vascularization was constructed using TA and Lys. In vitro experiments displayed that the CS-TA@Lys hydrogel possessed favorable mechanical properties and fast interaction performances. In addition, the CS-TA@Lys hydrogel possessed the capacity to remove intra/extracellular reactive oxygen species (ROS) and possessed antimicrobial and pro-angiogenic properties. In vivo experiments displayed that the CS-TA@Lys hydrogel inhibited wound inflammation and promoted wound vascularization. In addition, the CS-TA@Lys hydrogel showed the potential for rapid hemostasis. This study provides a potential functional wound dressing with rapid interaction properties for skin wound repair.
Topics: Humans; Chitosan; Antioxidants; Burns; Biocompatible Materials; Hydrogels; Neovascularization, Pathologic; Wound Healing; Anti-Bacterial Agents; Polyphenols
PubMed: 38494240
DOI: 10.1016/j.carbpol.2024.121991 -
Biomaterials Research Sep 2023Drug-resistant bacterial infections in chronic wounds are a persistent issue, as they are resistant to antibiotics and can cause excessive inflammation due to generation...
BACKGROUND
Drug-resistant bacterial infections in chronic wounds are a persistent issue, as they are resistant to antibiotics and can cause excessive inflammation due to generation of reactive oxygen species (ROS). An effective solution would be to not only combat bacterial infections but also scavenge ROS to relieve inflammation at the wound site. Scaffolds with antioxidant properties are attractive for their ability to scavenge ROS, and there is medical demand in developing antioxidant enzyme-mimicking nanomaterials for wound healing.
METHODS
In this study, we fabricated copper-coordination polymer nanoparticles (Cu-CPNs) through a self-assembly process. Furthermore, ε-polylysine (EPL), an antibacterial and cationic polymer, was integrated into the Cu-CPNs structure through a simple one-pot self-assembly process without sacrificing the glutathione peroxidase (GPx) and superoxide dismutase (SOD)-mimicking activity of Cu-CPNs.
RESULTS
The resulting Cu-CPNs exhibit excellent antioxidant propertiesin mimicking the activity of glutathione peroxidase and superoxide dismutase and allowing them to effectively scavenge harmful ROS produced in wound sites. The in vitro experiments showed that the resulting Cu-CPNs@EPL complex have superior antioxidant properties and antibacterial effects. Bacterial metabolic analysis revealed that the complex mainly affects the cell membrane integrity and nucleic acid synthesis that leads to bacterial death.
CONCLUSIONS
The Cu-CPNs@EPL complex has impressive antioxidant properties and antibacterial effects, making it a promising solution for treating drug-resistant bacterial infections in chronic wounds. The complex's ability to neutralize multiple ROS and reduce ROS-induced inflammation can help relieve inflammation at the wound site. Schematic illustration of the ROS scavenging and bacteriostatic function induced by Cu-CPNs@EPL nanozyme in the treatment of MRSA-infected wounds.
PubMed: 37723499
DOI: 10.1186/s40824-023-00429-z