New stealth amphiphilic copolymers based on polysarcosine (PSar) rather than poly(ethylene glycol) (PEG) have gained more attention for their use as excipients in nanomedicine. In this study, several polysarcosine-b-poly(γ-benzyl glutamate) (PSar-b-PGluOBn) block copolymers were synthesized by ring opening polymerization (ROP) of the respective N-carboxyanhydrides (NCAs) and were characterized by Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (H NMR) and size-exclusion chromatography (SEC). Copolymers had different PGluOBn block configuration (racemic L/D, pure L or pure D), degrees of polymerization of PSar between 28 and 76 and PGluOBn between 9 and 93, molar masses (M) between 5.0 and 24.6 kg.mol and dispersities (Đ) lower than 1.4. Nanoparticles of PSar-b-PGluOBn loaded with paclitaxel (PTX), a hydrophobic anti-cancer drug, were obtained by nanoprecipitation. Their hydrodynamic diameter (D) ranged from 27 to 118 nm with polydispersity indexes (PDI) between 0.01 and 0.20, as determined by dynamic light scattering (DLS). Their morphology was more spherical for copolymers with a racemic L/D PGluOBn block configuration synthesized at 5 °C. PTX loading efficiency was between 63 and 92 % and loading contents between 7 and 15 %. Using PSar-b-PGluOBn copolymers as excipients, PTX apparent water-solubility was significantly improved by a factor up to 6600 to 660 µg.mL.
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http://dx.doi.org/10.1016/j.ijpharm.2022.122501 | DOI Listing |
Anal Sci
December 2024
School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo, 192-0982, Japan.
A biosensor for biochemical oxygen demand (BOD) was developed based on intracellular 5'-adenosine triphosphate (ATP) measurements in Saccharomyces cerevisiae. Intracellular ATP was measured using an engineered protein named ATeam, comprising a bacterial FF-ATP synthase ε subunit sandwiched between cyan fluorescent protein and mVenus, a modified yellow fluorescent protein. Because the binding of ATP to ATeam induces changes in the fluorescence spectra owing to Fӧrster resonance energy transfer, S.
View Article and Find Full Text PDFMol Biotechnol
December 2024
Department of Biochemistry, Central University of Punjab, Ghudda, Bathinda, Punjab, 151401, India.
Staphylococcus warneri is a gram-positive mesophilic bacterium, resilient to extreme environmental conditions. To unravel its Osmotic Tolerance Response (OTR), we conducted proteomic and metabolomic analyses under drought (PEG) and salt (NaCl) stresses. Our findings revealed 1340 differentially expressed proteins (DEPs) across all treatments.
View Article and Find Full Text PDFPsychopharmacology (Berl)
December 2024
Bowles Center for Alcohol Studies, Department of Psychiatry, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Rationale: The positive reinforcing effects of alcohol (ethanol) drive repetitive use and contribute to alcohol use disorder (AUD). Ethanol alters the expression of glutamate AMPA receptor (AMPAR) subunits in reward-related brain regions, but the extent to which this effect regulates ethanol's reinforcing properties is unclear.
Objective: This study investigates whether ethanol self-administration changes AMPAR subunit expression and synaptic activity in the nucleus accumbens core (AcbC) to regulate ethanol's reinforcing effects in male C57BL/6 J mice.
Chem Biodivers
December 2024
Kitasato University: Kitasato Daigaku, Ōmura Satoshi Memorial Institute and Graduate School of Infection Control Sciences, 5-9-1 Shirokane, 1088641, Minato-ku, JAPAN.
The discovery of novel natural products through the exploration of distinct microorganisms is crucial for advancing drug discovery research. In this study, we focus on a unique environmental resource, microbial masses known as "Tengu-no-Mugimeshi." From the culture broth of Lecanicillium aphanocladii FKI-9593, isolated from Tengu-no-Mugimeshi collected at Mount Kurohime, Nagano Prefecture, Japan, we report the isolation of two novel tetrapeptides, tengupeptins A (1) and B (2), as well as the known compound oosporein.
View Article and Find Full Text PDFBackground: Temperature, as seen during fever, plays a pivotal role in modulating immune responses and maintaining cellular homeostasis. Shifts in temperature influence the thermodynamic feasibility of metabolic reactions, with Gibbs free energy (ΔG) serving as a key indicator of the spontaneity of reactions under specific conditions. By altering ΔG in response to temperature changes across various metabolite concentrations and cell types, we can gain insights into the thermodynamic properties of metabolic pathways and identify critical factors involved in metabolism and immune function.
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