Biotechnology and Bioprocess Engineering最新文献

Chinese hamster ovary (CHO) cells have been widely used in the biotechnology industry for the production of therapeutic proteins, leading to various research efforts to increase the productivity of therapeutic proteins. Although the addition of small molecule enhancers in CHO cell culture can enhance productivity, it poses a problem by negatively affecting product quality. In this study, effects of 4-phenylbutyrate (4-PBA), a chemical chaperone having a positive influence on recombinant protein production in CHO cells, were investigated. By varying the timing of 4-PBA addition, it was confirmed that the titer could be increased by 1.57-fold while reducing negative effects such as growth inhibition and apoptosis, thus preserving product quality. These effects of 4-PBA demonstrate the potential of using additive for developing novel enhancers for the production of recombinant proteins and the development of strategies for CHO cell engineering.

Plastics have been consistently produced for their practicality and convenience; however, unmanaged plastics often end up in the ocean and decompose into nano-plastics through photolytic decomposition and weathering, negatively affecting marine life. This can eventually affect humans via the food chain, highlighting the need for effective solutions. Microbial biodegradation has been proposed as a solution to minimize the impact of nano-plastics on the environment, and degradation byproducts can be used in microbial metabolic pathways. In this study, 57 bacterial strains were isolated and identified from a waste treatment facility. Bacterial strains with lipase activity were selected on Tween80 agar plates. Additionally, strains capable of growing on minimal salt agar plates supplemented with low-density polyethylene (LDPE) beads were selected. Incubation in a minimal salt medium with LDPE beads as the sole carbon source led to the selection of Pseudomonas plecoglossicida SYp2123, which is capable of degrading LDPE. This strain was subjected to high cell density culture, and Fourier-transform infrared spectroscopy revealed chemical changes on the surface of LDPE beads. Additionally, field-emission scanning electron microscopy confirmed substantial biodegradation of the surface. P. plecoglossicida SYp2123 was able to degrade LDPE beads. This discovery shows that P. plecoglossicida can potentially be used as an environmentally friendly approach for tackling issues associated with polyethylene waste.

Enterohemorrhagic Escherichia coli O157:H7 (EHEC) is responsible for outbreaks of hemorrhagic colitis worldwide, but no effective therapy exists for EHEC infections. EHEC readily forms antimicrobial-tolerant biofilms on various biotic and abiotic surfaces. Here, we investigated the antimicrobial and antibiofilm abilities of 16 halogenated (fluoro-, chloro-, bromo-, or iodo-) indoles and indole against a pathogenic EHEC strain. Antibiofilm activities followed the order chloroindoles > bromoindoles > indole > fluoroindoles. For example, the minimum inhibitory concentrations (MICs) of 4-bromoindole and 5-bromoindole were 100 and 200 μg/mL, respectively, and at 20 μg/mL, they both inhibited EHEC biofilm formation by more than 61% without affecting planktonic cell growth. However, at concentrations greater than their MICs, both showed bactericidal activity. Antibiofilm effects were confirmed by scanning electron microscopy. Both 4-bromoindole and 5-bromoindole reduced swimming and swarming motility and curli formation, which are important factors for EHEC biofilm formation. Furthermore, quantitative structure–activity relationship analysis demonstrated that halogenation of indole with chlorine, bromine, or iodine at positions C-4 or C-5 promotes antimicrobial activity but that substitution at C-7 is detrimental. The study shows that halogenated indoles, particularly bromoindoles, have potential use as antimicrobial and antibiofilm therapies against EHEC.

Plants contain many useful substances; however, their availability and uniformity are constrained. Controlled cell culture is attracting attention as a method for identifying useful substances with better quality control than conventional plant extraction techniques. Artificial skin is widely used as an alternative to animal testing to evaluate the safety and efficacy of cosmetic materials. The Damnacanthus major Siebold & Zucc is an evergreen shrub of the madder family, and the anthraquinone series substances present in its roots have antioxidant and whitening effects, implying its potential to be used in cosmetics. In this study, the antioxidant, moisturizing, and phototoxic properties of the ethanol extract of its callus were assessed using an artificial skin alternative. It showed a distinct antioxidant effect over 600 μg/mL and a moisturizing effect over 125 μg/mL. Phospho-extracellular signal-regulated kinase 1/2 and cAMP response element-binding protein were found to be upregulated in the artificial skin due to the moisturizing mechanism, and phospho-NFκB repressing factor was observed to be upregulated in human epidermal keratinocytes (HaCaT cells) due to the antioxidant mechanism. Additionally, analysis of the artificial skin revealed no phototoxicity up to 1 mg/mL. The results of this study demonstrate that the ethanol extract of Damnacanthus major Siebold & Zucc can be used as a cosmetic material.

Lipid-laden foam cells within the arterial walls play a key role in the development of atherosclerotic lesions at early disease stages, and they have been recognized as attractive targets for developing targeted therapeutics in atherosclerosis. Herein, we developed mannose-conjugated beta-cyclodextrin (MAN-βCD) and evaluated its targeting ability and intracellular cholesterol efflux toward cholesterol-laden foam cells. The synthesized MAN-βCD showed effective cholesterol extraction ability in aqueous conditions. The nontoxic and cytocompatible MAN-βCD specifically targeted cholesterol-laden foam cells with positive CD206 expressions and was internalized into the cells via receptor-mediated endocytosis. Additionally, the internalized MAN-βCD exhibited effective lipid droplet (LD) reduction within the cholesterol-laden foam cells, leading to remarkable prevention of LD accumulation. Therefore, the specific delivery of MAN-βCD into CD206-expressing lipid-laden foam cells provides a promising prevention strategy in the progression of atherosclerotic plaques.

In this study, bioengineered and biosynthesized elastin-like polypeptide (ELP) was adopted for a non-volatile memory resistive switching device or a memristor. The ELP mimicked from elastin of mammal was synthetically produced in polypeptide by Escherichia coli gene recombination. They were composed of a repeating pentapeptide sequence having [Val-Pro-Gly-Val-Gly]₃₂ sequence for bioelectronic devices with ELP showing multiple electrical resistance states between a high resistance state and a low resistance state through an applied electrical field. In addition, the ELP-coated 5-nm gold nanoparticles (Au NPs) layer was also to be biomaterials used for nanobiohybrid memristive devices. Simple metal–insulator–metal device structure and lateral electrode device with ELP layer on 5-nm Au NPs could show neuromorphic adaptive current–voltage (I–V) behavior and electrical stimulus-induced potentiation and depression in a hydrogel state. In addition, with an introduction of a neurotransmitter cortisol’s specific antibody, a preliminary sensing protocol was also examined with the nanobiohybrid device. Therefore, the introduction of ELP into neuromorphic device is regarded as the cornerstone for the development of biocompatible bioelectronic devices that can be integrated into human bionics for future artificial neuromorphic format.