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Bioelectrochemistry (Amsterdam,... Aug 2023The ability to study and regulate cell behavior at a biomaterial interface requires a strict control over its surface chemistry. Significance of studying cell adhesion...
The ability to study and regulate cell behavior at a biomaterial interface requires a strict control over its surface chemistry. Significance of studying cell adhesion in vitro and in vivo has become increasingly important, particularly in the field of tissue engineering and regenerative medicine. A promising surface modification route assumes using organic layers prepared by the method of electrografting of diazonium salts and their further functionalization with biologically active molecules as cell adhesion promoters. This work reports the modification of platinum electrodes with selected diazonium salts and poly-L-lysine to increase the number of sites available for cell adhesion. As-modified electrodes were characterized in terms of their chemical and morphological properties, as well as wettability. In order to monitor the process of cell attachment, biofunctionalized electrodes were used as substrates for culturing human neuroblastoma SH-SY5Y cells. The experiments revealed that cell adhesion is favored on the surface of diazonium-modified and poly-L-lysine coated electrodes, indicating proposed modification route as a valuable strategy enhancing the integration between bioelectronic devices and neural cells.
Topics: Humans; Cell Adhesion; Polylysine; Surface Properties; Salts; Neuroblastoma; Electrodes
PubMed: 37207477
DOI: 10.1016/j.bioelechem.2023.108465 -
The Journal of Antibiotics Sep 2023Streptomyces albulus NBRC14147 produces a homopoly(amino acid), ε-poly-L-lysine (ε-PL). Due to its antibiotic activity, thermostability, biodegradability, and...
Streptomyces albulus NBRC14147 produces a homopoly(amino acid), ε-poly-L-lysine (ε-PL). Due to its antibiotic activity, thermostability, biodegradability, and non-toxicity to humans, ε-PL is used as a food preservative. In this study, homology searches of diaminopimelate (DAP) pathway genes (dapB and dapE), in an S. albulus genome database, were shown to encode predicted enzymes using dapB or dapE in Escherichia coli strain complementation assays. We observed that dapB and dapE transcriptional levels were weak during ε-PL production stages. Therefore, we strengthened this expression using an ermE constitutive promoter. Engineered strains generated faster growth and ε-PL production rates when compared with the control strain. Moreover, maximum ε-PL yields in S. albulus, where dapB was constitutively expressed, were approximately 14% higher when compared with the control strain. These findings showed that enhanced lysine biosynthetic gene expression generated faster and higher ε-PL production levels.
Topics: Humans; Fermentation; Gene Expression; Polylysine; Streptomyces; Diaminopimelic Acid
PubMed: 37308604
DOI: 10.1038/s41429-023-00636-9 -
ACS Biomaterials Science & Engineering Nov 2023Poly(styrene--(ethylene--butylene)--styrene) (SEBS) with eminent elasticity, thermoplastic ability, and biological stability has aroused great interest in the medical...
Poly(styrene--(ethylene--butylene)--styrene) (SEBS) with eminent elasticity, thermoplastic ability, and biological stability has aroused great interest in the medical area. However, bacteria can easily adhere to the hydrophobic SEBS surface to cause medical device-related infections. In this work, SEBS is modified to prepare the SEBS-polydopamine (PDA)-poly(lysine) quaternary ammonium derivative (PLQ) antibacterial surface by PDA deposition and surface grafting techniques to solve bacterial infections. PDA is used as an intermediate layer and presents an excellent photothermal effect. The grafted polymer PLQ has antimicrobial quaternary ammonium cation groups, which plays synergistic bactericidal therapy with PDA. The SEBS-PDA-PLQ surface almost totally suppresses the growth of bacteria with a surface bacterial survival rate of 0.05% under laser irradiation. The outstanding antibacterial activity of the SEBS-PDA-PLQ surface is attributed to the synergistic effects of the photothermal performance of PDA and quaternary ammonium cationic functional groups of PLQ. In addition, the membrane SEBS-PDA-PLQ shows good hydrophilicity, antiprotein adsorption ability, chemical stability, and biocompatibility. This antibiotic-free antimicrobial approach has great potential for practical application in solving infections associated with medical devices.
Topics: Styrene; Anti-Bacterial Agents; Ammonium Compounds; Cations
PubMed: 37874178
DOI: 10.1021/acsbiomaterials.3c01135 -
Food Chemistry May 2024The shelf life of beef is shortened by microbial infection, which limits its supply in the market. Active packaging film is expected to overcome this difficulty. In this...
The shelf life of beef is shortened by microbial infection, which limits its supply in the market. Active packaging film is expected to overcome this difficulty. In this study, an antibacterial/antioxidant SS-ε-PL-TA biocomposite film made by soy protein isolate/sodium alginate/ε-polylysine/tannic acid was designed and prepared. Due to the formation of hydrogen bonds and enhanced hydrophobic interactions, the biocomposite film showed enhanced mechanical property. Tensile strength increased from 22.8 ± 2.59 MPa to 64.34 ± 6.22 MPa, and elongation at break increased from 7.70 ± 1.07 % to 13.98 ± 0.22 %. The composite film displayed excellent antibacterial activity owing to the damage to cell membranes and biofilms of bacteria. Furthermore, the antioxidant activity also significantly increased (DPPH ∙ scavenging activity was 78.0 %). The shelf life of beef covered with the SS-ε-PL-TA film was extended by 3 days compared to the control group by decreasing lipid oxidation and inhibiting bacterial growth, showing a good application potential in food packaging.
Topics: Animals; Cattle; Antioxidants; Polylysine; Chitosan; Anti-Bacterial Agents; Food Packaging
PubMed: 38081095
DOI: 10.1016/j.foodchem.2023.138155 -
Biomacromolecules Dec 2023The induction of disease states in animal models is an essential step in new drug discovery procedures. In this study, osteoarthritis (OA) was induced in a mouse model...
The induction of disease states in animal models is an essential step in new drug discovery procedures. In this study, osteoarthritis (OA) was induced in a mouse model using a polypeptide thermogel-based sustained drug release system. Hydrophilic lactobionic acids and hydrophobic -butyric acids were grafted onto ε-poly(l-lysine) to prepare a thermogelling polymer of ε-poly(l-lysine) grafted with lactobionic acid and butyric acid (PLLB). The gel modulus of PLLB is about 1000 Pa at 37 °C. Collagenase, which causes OA, was slowly released from the PLLB thermogel over two weeks. The PLLB formulation containing collagenases ranging from 1-10 units was intra-articularly injected into the knee of mice. OA mouse models with Osteoarthritis Research Society International (OARSI) grades of 3-6 were developed depending on the amounts of collagenase incorporated in the PLLB thermogel formulation. This study suggests that thermogel-based drug release formulations can be a precise tool for developing animal disease models in a dose-dependent manner.
Topics: Mice; Animals; Drug Liberation; Polylysine; Osteoarthritis; Disease Models, Animal; Collagenases
PubMed: 37939265
DOI: 10.1021/acs.biomac.3c01111 -
Journal of Colloid and Interface Science Dec 2023The use of tumor cell membrane-camouflaged nanoparticles, specifically the multifunctional biomimetic core-shell nanosystem MPCONPs, can enhance the targeting ability...
HYPOTHESIS
The use of tumor cell membrane-camouflaged nanoparticles, specifically the multifunctional biomimetic core-shell nanosystem MPCONPs, can enhance the targeting ability and immune escape functionality of traditional chemotherapy, leading to more precise drug delivery and improved treatment outcomes.
EXPERIMENTS
Preparation of MPCONPs: Autologous tumor cell membrane (CM) fragments are collected and used to create a shell for the nanoparticles. A trypsin-sensitive cationic polylysine framework is synthesized and embedded with oxaliplatin (l-OHP) and Ce6-AuNDs (a singlet oxygen generator). The MPCONPs are formed by assembling these components.
FINDINGS
MPCONPs, as nanoparticles camouflaged with tumor CM, have enhanced cellular uptake in cancer cells and improved the efficacy of photodynamic therapy (PDT) and chemotherapy (CT). This offers great potential for their use as individualized therapeutic agents for clinical oncology treatment.
Topics: Humans; Biomimetics; Photochemotherapy; Neoplasms; Cell Membrane; Nanoparticles; Cell Line, Tumor; Photosensitizing Agents
PubMed: 37619256
DOI: 10.1016/j.jcis.2023.08.109 -
Journal of Colloid and Interface Science Jan 2024Nanotheranostic agents combined the second near-infrared (NIR-II, 1000-1700 nm) fluorescence imaging with phototherapy strategy have attracted tremendous interest....
Nanotheranostic agents combined the second near-infrared (NIR-II, 1000-1700 nm) fluorescence imaging with phototherapy strategy have attracted tremendous interest. However, the actual efficacy of NIR-II probes could be weakened by their limited accumulation and penetration in tumor tissues. Herein, a size-transformable NIR-II nanotheranostic agent (BBT-HASS@FPMPL NPs) is employed for simultaneously enhanced penetration and retention in deep tumor tissue to realize precise image and effective PTT therapy. BBT-HASS@FPMPL NPs were first formed by using hyaluronic acid (HA) chains and disulfide bonds as stimuli-responsive "lock" to efficiently load conjugated oligomer (BBTN), and then folic acid (FA) modified polylysine (FPMPL) shell was stacked at the surface by electrostatic interaction. Dual targeting with HA and FA is expected to lead to more selective targeting and better accumulation of BBT-HASS@FPMPL NPs in tumor sites. Simultaneously, obvious particle size reduction and charge reversal can be triggered in acidic tumor microenvironment to achieve deep intratumor filtration through transcytosis. Following tumor penetration, size change was further initiated by overexpressed hyaluronidase and GSH in tumor. Free BBTN can be subsequently released from nanoparticles to promote specific intratumor retention, which synergistically enhance photothermal therapeutic efficacy. Owing to sufficient tumor accumulation and deep penetration, the NIR-II emission of BBTN could further be used for precise monitoring of subcutaneous tumor progression in mice for 6 days with just one dose injection. We expect that such nanotheranostic platform that combined the high resolution of NIR-II fluorescence with deep tumor penetration and long intratumor retention could be useful for real-time monitoring of tumor process, precise diagnosis, and enhanced phototherapy.
Topics: Mice; Animals; Theranostic Nanomedicine; Phototherapy; Neoplasms; Nanoparticles; Optical Imaging; Cell Line, Tumor; Tumor Microenvironment
PubMed: 37866046
DOI: 10.1016/j.jcis.2023.10.038 -
Physical Chemistry Chemical Physics :... Jul 2023We show by extensive experimental characterization combined with molecular simulations that pH has a major impact on the assembly mechanism and properties of...
We show by extensive experimental characterization combined with molecular simulations that pH has a major impact on the assembly mechanism and properties of poly(L-lysine) (PLL) and poly(L-glutamic acid) (PGA) complexes. A combination of dynamic light scattering (DLS) and laser Doppler velocimetry (LDV) is used to assess the complexation, charge state, and other physical characteristics of the complexes, isothermal titration calorimetry (ITC) is used to examine the complexation thermodynamics, and circular dichroism (CD) is used to extract the polypeptides' secondary structure. For enhanced analysis and interpretation of the data, analytical ultracentrifugation (AUC) is used to define the precise molecular weights and solution association of the peptides. Molecular dynamics simulations reveal the associated intra- and intermolecular binding changes in terms of intrinsic extrinsic charge compensation, the role of hydrogen bonding, and secondary structure changes, aiding in the interpretation of the experimental data. We combine the data to reveal the pH dependency of PLL/PGA complexation and the associated molecular level mechanisms. This work shows that not only pH provides a means to control complex formation but also that the associated changes in the secondary structure and binding conformation can be systematically used to control materials assembly. This gives access to rational design of peptide materials pH control.
Topics: Polylysine; Glutamic Acid; Peptides; Protein Structure, Secondary; Hydrogen-Ion Concentration; Circular Dichroism
PubMed: 37387688
DOI: 10.1039/d3cp01421e -
ACS Applied Materials & Interfaces Jan 2024Developing strategies for the treatment of bacterial biofilms is challenging due to their complex and resilient structure, low permeability to therapeutics, and ability...
Developing strategies for the treatment of bacterial biofilms is challenging due to their complex and resilient structure, low permeability to therapeutics, and ability to protect resident pathogens. Herein, we demonstrate that a polylysine-stabilized perfluorocarbon nanoemulsion is favored for penetrating biofilms and sensitizing the cavitation effect of low-intensity ultrasound, resulting in the dispersal of extracellular polymeric substances and killing of the protected cells. Through experiments, we observed a complete penetration of the nanoemulsion in a 40 μm biofilm and demonstrated that it was induced by the fluidic perfluorocarbon, possibly attributing to its low surface tension. Furthermore, we presented an almost complete antibiofilm effect with a low-intensity ultrasound (1 MHz, 0.75 W/cm, 5 min) in diverse cases, including cultured biofilms, colonized urinary catheters, and chronic wounds. During the treatment process, the perfluorocarbon phase enhanced the number and imploding energy of ultrasound cavities, thoroughly divided the biofilm structure, prevented biofilm self-healing, and sterilized the resident pathogens. Thus, the penetration and sensitization of the nanoemulsion might serve as a facile and potent strategy for eradicating biofilms in various applications.
Topics: Humans; Anti-Bacterial Agents; Biofilms; Pseudomonas Infections; Light; Pseudomonas aeruginosa
PubMed: 38191301
DOI: 10.1021/acsami.3c15167 -
Journal of Colloid and Interface Science Aug 2024A key challenge to enhance the therapeutic outcome of photothermal therapy (PTT) is to improve the efficiency of passive targeted accumulation of photothermal agents at...
A key challenge to enhance the therapeutic outcome of photothermal therapy (PTT) is to improve the efficiency of passive targeted accumulation of photothermal agents at tumor sites. Carbon dots (CDs) are an ideal choice for application as photothermal agents because of their advantages such as adjustable fluorescence, high photothermal conversion efficiency, and excellent biocompatibility. Here, we synthesized polylysine-modified near-infrared (NIR)-emitting CDs assemblies (plys-CDs) through post-solvothermal reaction of NIR-emitting CDs with polylysine. The encapsulated structure of plys-CDs was confirmed by determining morphological, chemical, and luminescent properties. The particle size of CDs increased to approximately 40 ± 8 nm after polylysine modification and was within the size range appropriate for achieving superior enhanced permeability and retention effect. Plys-CDs maintained a high photothermal conversion efficiency of 54.9 %, coupled with increased tumor site accumulation, leading to a high efficacy in tumor PTT. Thus, plys-CDs have a great potential for application in photothermal ablation therapy of tumors.
Topics: Polylysine; Carbon; Photothermal Therapy; Animals; Quantum Dots; Mice; Infrared Rays; Particle Size; Humans; Mice, Inbred BALB C; Surface Properties; Female; Cell Survival; Neoplasms
PubMed: 38669991
DOI: 10.1016/j.jcis.2024.04.153