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International Journal of Biological... Jul 2023Food packaging plays an extremely important role in the global food chain, allowing for products to be shipped across long distances without spoiling. However, there is...
Food packaging plays an extremely important role in the global food chain, allowing for products to be shipped across long distances without spoiling. However, there is an increased need to both reduce plastic waste caused by traditional single-use plastic packaging and improve the overall functionality of packaging materials to extend shelf-life even further. Herein, we investigate composite mixtures based on cellulose nanofibers and carvacrol via stabilizing octenyl-succinic anhydride-modified epsilon polylysine (MɛPL-CNF) for active food packaging applications. The effects of epsilon polylysine (εPL) concentration and modification with octenyl-succinic anhydride (OSA) and carvacrol are evaluated with respect to composites morphology, mechanical, optical, antioxidant, and antimicrobial properties. We find that both increased εPL concentration and modification with OSA and carvacrol lead to films with increased antioxidant and antimicrobial properties, albeit at the expense of reduced mechanical performance. Importantly, when sprayed onto the surface of sliced apples, MεPL-CNF-mixtures are able to successfully delay/hinder enzymatic browning, suggesting the potential of such materials for a range of active food packaging applications.
Topics: Polylysine; Cellulose; Nanofibers; Succinic Anhydrides; Antioxidants; Anti-Infective Agents; Food Packaging; Nanocomposites; Plastics
PubMed: 37201880
DOI: 10.1016/j.ijbiomac.2023.124869 -
Nanoscale Advances May 2023Cellular transport systems are sophisticated and efficient. Hence, one of the ultimate goals of nanotechnology is to design artificial transport systems rationally....
Cellular transport systems are sophisticated and efficient. Hence, one of the ultimate goals of nanotechnology is to design artificial transport systems rationally. However, the design principle has been elusive, because how motor layout affects motile activity has not been established, partially owing to the difficulty in achieving a precise layout of the motile elements. Here, we employed a DNA origami platform to evaluate the two-dimensional (2D) layout effect of kinesin motor proteins on transporter motility. We succeeded in accelerating the integration speed of the protein of interest (POI) to the DNA origami transporter by up to 700 times by introducing a positively charged poly-lysine tag (Lys-tag) into the POI (kinesin motor protein). This Lys-tag approach allowed us to construct and purify a transporter with high motor density, allowing a precise evaluation on the 2D layout effect. Our single-molecule imaging showed that the densely packed layout of kinesin decreased the run length of the transporter, although its velocity was moderately affected. These results indicate that steric hindrance is a critical parameter to be considered in the design of transport systems.
PubMed: 37143804
DOI: 10.1039/d3na00088e -
Biomaterials Research May 2023Antibacterial activity and on-demand removability are key characteristics governing the effectiveness of clinic wound dressing. However, the excellent tissue adhesion of...
BACKGROUND
Antibacterial activity and on-demand removability are key characteristics governing the effectiveness of clinic wound dressing. However, the excellent tissue adhesion of new dressings is often overemphasized without a detailed discussion of dressing replacement. Besides, the inherent antibacterial ability of dressings is beneficial for promoting the healing of infected wound. Therefore, we rationally design an injectable antibacterial wound dressing with on-demand removability to accelerate infected wound healing.
METHOD
We design this wound dressing with a simple and feasible method based on the electrostatic self-assembly of hyaluronic acid and ε-polylysine. We investigated the efficacy of this dressing in terms of its microtopography, rheology, self-healing performance, adhesive ability, antimicrobial, hemostatic, on-demand removal properties, and wound healing promotion through various tests.
RESULTS
The prepared dressing possesses injectability, self-healing ability and antibacterial activity, showing NaCl-triggered on-demand dissolution due to the disruption of electrostatic interactions. When used as dressings for healing full-thickness wounds, it could effectively accelerate wound healing by killing bacteria, downregulating inflammation, promoting collagen deposition, enhancing keratinocyte migration and angiogenesis due to its excellent adhesion ability, favorable hemostatic property, and potent antibacterial performance.
CONCLUSION
All results indicate that this is a simple and practical dressing for clinical application. This strategy provides a novel idea for developing on-demand removal dressings with antibacterial and injectable properties.
PubMed: 37127622
DOI: 10.1186/s40824-023-00340-7 -
Journal of Cell Communication and... Sep 2023Ras GTPases are central to cellular signaling and oncogenesis. The three loci of the Ras gene encode for four protein isoforms namely Harvey-Ras (H-Ras), Kirsten-Ras...
Ras GTPases are central to cellular signaling and oncogenesis. The three loci of the Ras gene encode for four protein isoforms namely Harvey-Ras (H-Ras), Kirsten-Ras (K-Ras 4A and 4B), and Neuroblastoma-Ras (N-Ras) which share ~ 80% sequence similarity and used to be considered functionally redundant. The small molecule inhibitors of Ras lack specificity for the isoforms leading to widespread toxicity in Ras-targeted therapeutics. Ras isoforms' tissue-specific expression and selective association with carcinogenesis, embryonic development, and infection suggested their non-redundancy. We show that CD40, an antigen-presenting cell (APC)-expressed immune receptor, induces selective relocation of H-Ras, K-Ras, and N-Ras to the Plasma membrane (PM) lipid rafts, mitochondria, endoplasmic reticulum (ER), but not to the Golgi complex (GC). The two palmitoylated Ras isoforms-H-Ras and N-Ras-have a similar pattern of colocalization into the lipid-rich raft microdomain of the PM at early time points when compared to non-palmitoylated K-Ras (4B) with polylysine residues. CD40-induced trafficking of H-Ras and K-Ras to mitochondria and ER was found to be similar but different from that of N-Ras. Trafficking of all the Ras isoforms to the GC was independent of CD40 stimulation. The receptor-driven trafficking and spatial segregation of H-Ras, K-Ras, and N-Ras imply isoform-specific subcellular signaling platforms for the functional non-redundancy of Ras isoforms. PDB structures have been modified to illustrate various signaling proteins.
PubMed: 37126117
DOI: 10.1007/s12079-023-00747-w -
Journal of Neuroscience Methods May 2023The blood-brain barrier (BBB) is a protective cellular anatomical layer with a dynamic micro-environment, tightly regulating the transport of materials across it. To...
The blood-brain barrier (BBB) is a protective cellular anatomical layer with a dynamic micro-environment, tightly regulating the transport of materials across it. To achieve in-vivo characteristics, an in-vitro BBB model requires the constituent cell types to be layered in an appropriate order. A cost-effective in-vitro BBB model is desired to facilitate central nervous system (CNS) drug penetration studies. Enhanced integrity of tight junctions observed during the in-vitro BBB establishment and post-experiment is essential in these models. We successfully developed an in-vitro BBB model mimicking the in-vivo cell composition and a distinct order of seeding primary human brain cells. Unlike other in-vitro BBB models, our work avoids the need for pre-coated plates for cell adhesion and provides better cell visualization during the procedure. We found that using bovine collagen-I coating, followed by bovine fibronectin coating and poly-L-lysine coating, yields better adhesion and layering of cells on the transwell membrane compared to earlier reported use of collagen and poly-L-lysine only. Our results indicated better cell visibility and imaging with the polyester transwell membrane as well as point to a higher and more stable Trans Endothelial Electrical Resistance values in this plate. In addition, we found that the addition of zinc induced higher claudin 5 expressions in neuronal cells. Dolutegravir, a drug used in the treatment of HIV, is known to appear in moderate concentrations in the CNS. Thus, dolutegravir was used to assess the functionality of the final model and cells. Using primary cells and an in-house coating strategy substantially reduces costs and provides superior imaging of cells and their tight junction protein expression. Our 4-cell-based BBB model is a suitable experimental model for the drug screening process.
Topics: Animals; Cattle; Humans; Blood-Brain Barrier; Cell Line; Polylysine; Endothelial Cells; Microscopy, Confocal
PubMed: 37116621
DOI: 10.1016/j.jneumeth.2023.109867 -
Polymers Apr 2023The reduction of tissue cytotoxicity and the improvement of cell viability are of utmost significance, particularly in the realm of green chemistry. Despite substantial...
The reduction of tissue cytotoxicity and the improvement of cell viability are of utmost significance, particularly in the realm of green chemistry. Despite substantial progress, the threat of local infections remains a concern. Therefore, hydrogel systems that provide mechanical support and a harmonious balance between antimicrobial efficacy and cell viability are greatly needed. Our study explores the preparation of physically crosslinked, injectable, and antimicrobial hydrogels using biocompatible hyaluronic acid (HA) and antimicrobial ε-polylysine (ε-PL) in different weight ratios (10 wt% to 90 wt%). The crosslinking was achieved by forming a polyelectrolyte complex between HA and ε-PL. The influence of HA content on the resulting HA/ε-PL hydrogel physicochemical, mechanical, morphological, rheological, and antimicrobial properties was evaluated, followed by an inspection of their in vitro cytotoxicity and hemocompatibility. Within the study, injectable, self-healing HA/ε-PL hydrogels were developed. All hydrogels showed antimicrobial properties against , , , and , where HA/ε-PL 30:70 (wt%) composition reached nearly 100% killing efficiency. The antimicrobial activity was directly proportional to ε-PL content in the HA/ε-PL hydrogels. A decrease in ε-PL content led to a reduction of antimicrobial efficacy against and . Conversely, this decrease in ε-PL content in HA/ε-PL hydrogels was favourable for Balb/c 3T3 cells, leading to the cell viability of 152.57% for HA/ε-PL 70:30 and 142.67% for HA/ε-PL 80:20. The obtained results provide essential insights into the composition of the appropriate hydrogel systems able to provide not only mechanical support but also the antibacterial effect, which can offer opportunities for developing new, patient-safe, and environmentally friendly biomaterials.
PubMed: 37112064
DOI: 10.3390/polym15081915 -
Bioactive Materials Jul 2023Native-like endothelium regeneration is a prerequisite for material-guided small-diameter vascular regeneration. In this study, a novel strategy is proposed to achieve...
Native-like endothelium regeneration is a prerequisite for material-guided small-diameter vascular regeneration. In this study, a novel strategy is proposed to achieve phase-adjusted endothelial healing by step-wise modification of parallel-microgroove-patterned (i.e., micropatterned) nanofibers with polydopamine-copper ion (PDA-Cu) complexes, polylysine (PLys) molecules, and Cys-Ala-Gly (CAG) peptides (CAG@PLys@PDA-Cu). Using electrospun poly(-lactide--caprolactone) random nanofibers as the demonstrating biomaterial, step-wise modification of CAG@PLys@PDA-Cu significantly enhanced substrate wettability and protein adsorption, exhibited an excellent antithrombotic surface and outstanding phase-adjusted capacity of endothelium regeneration involving cell adhesion, endothelial monolayer formation, and the regenerated endothelium maturation. Upon implantation for segmental replacement of rabbit carotid arteries, CAG@PLys@PDA-Cu modified grafts (2 mm inner diameter) with micropatterns on inner surface effectively accelerated native-like endothelium regeneration within 1 week, with less platelet aggregates and inflammatory response compared to those on non-modified grafts. Prolonged observations at 6- and 12-weeks post-implantation demonstrated a positive vascular remodeling with almost fully covered endothelium and mature smooth muscle layer in the modified vascular grafts, accompanied with well-organized extracellular matrix. By contrast, non-modified vascular grafts induced a disorganized tissue formation with a high risk of thrombogenesis. In summary, step-wise modification of CAG@PLys@PDA-Cu on micropatterned nanofibers can significantly promote endothelial healing without inflicting thrombosis, thus confirming a novel strategy for developing functional vascular grafts or other blood-contacting materials/devices.
PubMed: 37056258
DOI: 10.1016/j.bioactmat.2022.07.010 -
Foods (Basel, Switzerland) Mar 2023Thermosonication (TS) has been identified as a smart remedy for the shortcomings of heat treatment, which typically requires prolonged exposure to high temperatures.... (Review)
Review
Thermosonication (TS) has been identified as a smart remedy for the shortcomings of heat treatment, which typically requires prolonged exposure to high temperatures. This technique combines moderate heat treatment with acoustic energy to eliminate harmful microorganisms and enzymes in food products. Unlike conventional heat treatment, thermosonication utilizes short holding times, allowing for the preservation of food products' phytochemical compounds and sensory characteristics. The benefits and challenges of this emerging technology, such as equipment cost, limited availability of data, inconsistent results, high energy consumption, and scale-up challenges, have been assessed, and the design process for using ultrasound in combination with mild thermal treatment has been discussed. TS has proven to be a promising technique for eliminating microorganisms and enzymes without compromising the nutritional or sensory quality of food products. Utilizing natural antimicrobial agents such as ascorbic acid, Nisin, and ε-polylysine (ε-PL) in combination with thermosonication is a promising approach to enhancing the safety and shelf life of food products. Further research is required to enhance the utilization of natural antimicrobial agents and to acquire a more comprehensive comprehension of their impact on the safety and quality of food products.
PubMed: 37048278
DOI: 10.3390/foods12071459 -
Biomedicine & Pharmacotherapy =... Jun 2023Drug delivery systems require that carrier materials have good biocompatibility, degradability, and constructability. Poly(amino acids), a substance with a distinctive...
Drug delivery systems require that carrier materials have good biocompatibility, degradability, and constructability. Poly(amino acids), a substance with a distinctive secondary structure, not only have the basic features of the carrier materials but also have several reactive functional groups in the side chain, which can be employed as drug carriers to deliver anticancer drugs. The conformation of isomers of drug carriers has some influence on the preparation, morphology, and efficacy of nanoparticles. In this study, two isomers of polylysine, including ε-polylysine (ε-PL) and α-polylysine (α-PL), were used as drug carriers to entrap methotrexate (MTX) and construct nano-drug delivery systems. ε-PL/MTX nanoparticles with the morphology of helical nanorods presented a small particle size (115.0 nm), and relative high drug loading content (57.8 %). The anticancer effect of ε-PL/MTX nanoparticles was 1.3-fold and 2.6-fold stronger than that of α-PL/MTX nanoparticles in vivo and in vitro, respectively. ε-PL is an ideal drug carrier with potential clinical application prospects.
Topics: Methotrexate; Polylysine; Antineoplastic Agents; Drug Carriers; Nanoparticles
PubMed: 37037095
DOI: 10.1016/j.biopha.2023.114662 -
Allergy, Asthma & Immunology Research Mar 2023Clavulanate, a beta-lactam associated with amoxicillin, is frequently prescribed in patients at all ages. Recent data implicate amoxicillin-clavulanate in up to 80% of...
PURPOSE
Clavulanate, a beta-lactam associated with amoxicillin, is frequently prescribed in patients at all ages. Recent data implicate amoxicillin-clavulanate in up to 80% of beta-lactam allergy cases. We assessed clavulanate's role in inducing allergic reactions to this combination treatment, with a focus on selective immediate reactions.
METHODS
Adults (≥ 16 years) reporting a history of immediate reactions to amoxicillin-clavulanate were evaluated through a beta-lactam allergological workup, using modified European Academy of Allergy and Clinical Immunology guidelines. Patients first underwent skin testing, and if negative, drug provocation tests. Expected outcomes were: Group A, subjects with immediate reaction to classical penicillin group determinants (penicilloyl polylysine, minor determinants mixture, and/or penicillin G); Group B, subjects with selective immediate reaction to amoxicillin; Group C, subjects with selective immediate reaction to clavulanate and Group D, those immediate reactions with co-sensitization to clavulanate plus penicillin group determinants or amoxicillin.
RESULTS
Of 1,170 included patients, 104 had immediate reactions: 36.5% to penicillin group determinants (Group A), 26.9% to amoxicillin (Group B), 32.7% to clavulanate (Group C), and 3.8% to clavulanate plus penicillin determinants or amoxicillin (Group D). Diagnosis was made by skin testing in 79%, 75% and 47% of the patients, respectively, in the first 3 groups ( < 0.001). Drug provocation tests were necessary to establish most other diagnoses. Anaphylaxis predominated over urticaria/angioedema in all groups.
CONCLUSIONS
Selective immediate reactions to clavulanate accounted for over a third of cases with confirmed reactions after amoxicillin-clavulanate intake, with more than half experiencing anaphylaxis. Within this group, skin test sensitivity was below 50%. People taking amoxicillin-clavulanate may also be co-sensitized to both drugs.
PubMed: 37021506
DOI: 10.4168/aair.2023.15.2.201