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Scientific Reports Oct 2021Introducing bacteriophage MS2 virus-like particles (VLPs) as gene and drug delivery tools increases the demand for optimizing their production and purification...
Introducing bacteriophage MS2 virus-like particles (VLPs) as gene and drug delivery tools increases the demand for optimizing their production and purification procedure. PEG precipitation method is used efficiently to purify VLPs, while the effects of pH and different electrolytes on the stability, size, and homogeneity of purified MS2 VLPs, and the encapsulated RNA sequences remained to be elucidated. In this regard, a vector, capable of producing VLP with an shRNA packed inside was prepared. The resulting VLPs in different buffers/solutions were assessed for their size, polydispersity index, and ability to protect the enclosed shRNA. We report that among Tris, HEPES, and PBS, with or without NaNO3, and also NaNO3 alone in different pH and ionic concentrations, the 100 mM NaNO3-Tris buffer with pH:8 can be used as a new and optimal MS2 VLP production buffer, capable of inhibiting the VLPs aggregation. These VLPs show a size range of 27-30 nm and suitable homogeneity with minimum 12-month stability at 4 °C. Moreover, the resulting MS2 VLPs were highly efficient and stable for at least 48 h in conditions similar to in vivo. These features of MS2 VLPs produced in the newly introduced buffer make them an appropriate candidate for therapeutic agents' delivery.
Topics: Buffers; Cell Line; Chemical Fractionation; Humans; Hydrogen-Ion Concentration; Levivirus; Nitrates; Particle Size; Virion
PubMed: 34615923
DOI: 10.1038/s41598-021-98706-1 -
Nature Communications Nov 2022Unlike artificial nanosystems, biological systems are ideally engineered to respond to their environment. As such, natural molecular buffers ensure precise and...
Unlike artificial nanosystems, biological systems are ideally engineered to respond to their environment. As such, natural molecular buffers ensure precise and quantitative delivery of specific molecules through self-regulated mechanisms based on Le Chatelier's principle. Here, we apply this principle to design self-regulated nucleic acid molecular buffers for the chemotherapeutic drug doxorubicin and the antimalarial agent quinine. We show that these aptamer-based buffers can be programmed to maintain any specific desired concentration of free drug both in vitro and in vivo and enable the optimization of the chemical stability, partition coefficient, pharmacokinetics and biodistribution of the drug. These programmable buffers can be built from any polymer and should improve patient therapeutic outcome by enhancing drug activity and minimizing adverse effects and dosage frequency.
Topics: Humans; Tissue Distribution; Doxorubicin; Polymers; Pharmaceutical Preparations; Drug Delivery Systems; Buffers
PubMed: 36323663
DOI: 10.1038/s41467-022-33491-7 -
Analytica Chimica Acta Apr 2020Electromembrane extraction (EME) in small, stagnant and chip-like devices has the potential for future in-field operation. Literature briefly discuss such systems, but...
Electromembrane extraction (EME) in small, stagnant and chip-like devices has the potential for future in-field operation. Literature briefly discuss such systems, but performance suffered from evaporative losses of sample and acceptor. To address this, the current paper reports electromembrane extraction (EME) of five basic drugs (model analytes) from aqueous buffer solutions and whole blood samples under stagnant conditions in a completely closed system. A laboratory-made polyoxymethylene (POM) well plate served as compartment for the sample solution, while a commercially available well filter plate was used to immobilize 2-nitrophenyl octyl ether (NPOE) as supported liquid membrane (SLM) and as closed compartment for the acceptor solution. Major design parameters (sample compartment and electrode geometry) and operational parameters (sample volume, voltage and extraction time) were investigated and optimized. Electrode geometry was not very critical, but extraction efficiency increased with decreasing sample volume. Extraction from 50 μL aqueous buffer solution for 60 min and with a voltage of 75 V was considered exhaustive (sample was depleted), with recoveries ranging between 75% and 87% for loperamide, haloperidol, methadone, nortriptyline, and pethidine (RSD: 2-12%). Extraction from whole blood samples under optimized conditions yielded slightly lower recoveries, ranging between 57 and 96% (RSD: 3-12%). Stagnant EME was evaluated in combination with liquid chromatography-mass spectrometry (LC-MS) as a highly specific instrumental method, and provided evaluation data on methadone from blood samples in accordance with regulatory requirements (LOD: 0.4 ng/mL, LOQ: 1.4 ng/mL, RSD: 6-20%). This work has improved upon the design of stagnant EME, moving it further towards a viable in-field operation device.
Topics: Buffers; Chromatography, Liquid; Electrochemical Techniques; Electrodes; Ethers; Healthy Volunteers; Humans; Limit of Detection; Mass Spectrometry; Membranes, Artificial; Pharmaceutical Preparations; Resins, Synthetic
PubMed: 32106938
DOI: 10.1016/j.aca.2020.01.058 -
Surgery Mar 2022Massive transfusion with older packed red blood cells is associated with increased morbidity and mortality. As packed red blood cells age, they undergo biochemical and...
BACKGROUND
Massive transfusion with older packed red blood cells is associated with increased morbidity and mortality. As packed red blood cells age, they undergo biochemical and structural changes known as the storage lesion. We developed a novel solution to increase viscosity in stored packed red blood cells. We hypothesized that packed red blood cell storage in this solution would blunt storage lesion formation and mitigate the inflammatory response after resuscitation.
METHODS
Blood was obtained from 8- to 10-week-old C57BL/6 male donor mice or human volunteers and stored as packed red blood cell units for 14 days for mice or 42 days for humans in either standard AS-3 storage solution or EAS-1587, the novel packed red blood cell storage solution. Packed red blood cells were analyzed for microvesicles, cell-free hemoglobin, phosphatidylserine, band-3 protein, glucose utilization, and osmotic fragility. Additional mice underwent hemorrhage and resuscitation with packed red blood cells stored in either AS-3 or EAS-1587. Serum was analyzed for inflammatory markers.
RESULTS
Murine packed red blood cells stored in EAS-1587 demonstrated reductions in microvesicle and cell-free hemoglobin accumulation as well as preserved band-3 expression, increase glucose utilization, reductions in phosphatidylserine expression, and susceptibility to osmotic stress. Serum from mice resuscitated with packed red blood cells stored in EAS-1587 demonstrated reduced proinflammatory cytokines. Human packed red blood cells demonstrated a reduction in microvesicle and cell-free hemoglobin as well as an increase in glucose utilization.
CONCLUSION
Storage of packed red blood cells in a novel storage solution mitigated many aspects of the red blood cell storage lesion as well as the inflammatory response to resuscitation after hemorrhage. This modified storage solution may lead to improvement of packed red blood cell storage and reduce harm after massive transfusion.
Topics: Adenine; Animals; Blood Preservation; Buffers; Citrates; Disease Models, Animal; Erythrocytes; Glucose; Humans; Male; Mice; Mice, Inbred C57BL; Organ Preservation Solutions; Phosphates; Shock, Hemorrhagic; Sodium Chloride; Time Factors; Viscosity
PubMed: 34974917
DOI: 10.1016/j.surg.2021.11.020 -
Nature Communications Apr 2023Transcriptional changes in Rett syndrome (RTT) are assumed to directly correlate with steady-state mRNA levels, but limited evidence in mice suggests that changes in...
Transcriptional changes in Rett syndrome (RTT) are assumed to directly correlate with steady-state mRNA levels, but limited evidence in mice suggests that changes in transcription can be compensated by post-transcriptional regulation. We measure transcription rate and mRNA half-life changes in RTT patient neurons using RATEseq, and re-interpret nuclear and whole-cell RNAseq from Mecp2 mice. Genes are dysregulated by changing transcription rate or half-life and are buffered when both change. We utilized classifier models to predict the direction of transcription rate changes and find that combined frequencies of three dinucleotides are better predictors than CA and CG. MicroRNA and RNA-binding Protein (RBP) motifs are enriched in 3'UTRs of genes with half-life changes. Nuclear RBP motifs are enriched on buffered genes with increased transcription rate. We identify post-transcriptional mechanisms in humans and mice that alter half-life or buffer transcription rate changes when a transcriptional modulator gene is mutated in a neurodevelopmental disorder.
Topics: Humans; Mice; Animals; Rett Syndrome; RNA, Messenger; Half-Life; Methyl-CpG-Binding Protein 2; Gene Expression Regulation
PubMed: 37019888
DOI: 10.1038/s41467-023-37339-6 -
Frontiers in Endocrinology 2022Reducing injection-site pain (ISP) in patients with chronic conditions such as growth hormone deficiency is a valuable strategy to improve patient compliance and... (Review)
Review
Reducing injection-site pain (ISP) in patients with chronic conditions such as growth hormone deficiency is a valuable strategy to improve patient compliance and therapeutic efficiency. Thus understanding different aspects of pain induction following subcutaneous injection of biotherapeutics and identifying the responsible factors are vital. Here we have discussed the effects of formulation's viscosity, concentration, osmolality, buffering agents, pH, and temperature as well as injection volume, dosing frequency, and different excipients on ISP following subcutaneous injection of commercially available recombinant human growth hormone products. Our literature review found limited available data on the effects of different components of parenteral rhGH products on ISP. This may be due to high cost associated with conducting various clinical trials to assess each excipient in the formulation or to determine the complex interactions of different components and its impact on ISP. Recently, conducting molecular dynamics simulation studies before formulation design has been recommended as an alternative and less-expensive approach. On the other hand, the observed inconsistencies in the available data is mainly due to different pain measurement approaches used in each study. Moreover, it is difficult to translate data obtained from animal studies to human subjects. Despite all these limitations, our investigation showed that components of parenteral rhGH products can significantly contribute to ISP. We suggest further investigation is required for development of long acting, buffer-free, preservative-free formulations. Besides, various excipients are currently being investigated for reducing ISP which can be used as alternatives for common buffers, surfactants or preservatives in designing future rhGH formulations.
Topics: Animals; Humans; Human Growth Hormone; Excipients; Growth Hormone; Pain; Recombinant Proteins; Surface-Active Agents
PubMed: 36263321
DOI: 10.3389/fendo.2022.963336 -
ELife Mar 2021Glia modulate neuronal excitability and seizure sensitivity by maintaining potassium and water homeostasis. A salt inducible kinase 3 (SIK3)-regulated gene expression...
Glia modulate neuronal excitability and seizure sensitivity by maintaining potassium and water homeostasis. A salt inducible kinase 3 (SIK3)-regulated gene expression program controls the glial capacity to buffer K and water in , however upstream regulatory mechanisms are unknown. Here, we identify an octopaminergic circuit linking neuronal activity to glial ion and water buffering. Under basal conditions, octopamine functions through the inhibitory octopaminergic G-protein-coupled receptor (GPCR) OctβR to upregulate glial buffering capacity, while under pathological K stress, octopamine signals through the stimulatory octopaminergic GPCR OAMB1 to downregulate the glial buffering program. Failure to downregulate this program leads to intracellular glia swelling and stress signaling, suggesting that turning down this pathway is glioprotective. In the seizure model, the SIK3-mediated buffering pathway is inactivated. Reactivation of the glial buffering program dramatically suppresses neuronal hyperactivity, seizures, and shortened life span in this mutant. These findings highlight the therapeutic potential of a glial-centric therapeutic strategy for diseases of hyperexcitability.
Topics: Animals; Drosophila melanogaster; Gene Expression Regulation; Larva; Neuroglia; Neuroprotection; Octopamine; Potassium; Protein Serine-Threonine Kinases; Receptors, G-Protein-Coupled; Seizures; Water
PubMed: 33646119
DOI: 10.7554/eLife.62606 -
Frontiers in Psychology 2022In 2017, the blockade of Qatar Gulf states caused a plethora of effects on the country. This paper sought to examine the resulting threat effects of this blockade in...
In 2017, the blockade of Qatar Gulf states caused a plethora of effects on the country. This paper sought to examine the resulting threat effects of this blockade in terms of lowered self-esteem and well-being, and the potential buffering effects of an overarching identity. Using self-report questionnaire data from Qatari secondary school students ( = 1,410), multiple moderated mediation models investigated the predictive effects of youngsters' perceived threat, self-esteem, on their well-being, and the mitigating roles herein of, respectively, national, Gulf region, and Arab identity. Perceived threat was indeed related to lower well-being lower self-esteem, and this relationship was equally strong for those low and high in social identity. In terms of the three facets of identity, the overarching Gulf identity seems the most predictive, and it even (marginally significantly) buffers the negative relationship between threat and reduced self-esteem.
PubMed: 35432059
DOI: 10.3389/fpsyg.2022.750471 -
Hydrological Processes Nov 2022Buffer strips continue to feature in the management of agricultural runoff and water pollution in many countries. Existing research has explored their efficacy for...
Buffer strips continue to feature in the management of agricultural runoff and water pollution in many countries. Existing research has explored their efficacy for reducing environmental problems in different geoclimatic settings but, the evidence on the efficacy of different vegetation treatments is less abundant than that for other buffer strip characteristics, including width, and is more contradictory in nature. With policy targets for various environmental outcomes including water or air quality and net zero pointing to the need for conversion of agricultural land, the need for robust experimental evidence on the relative benefits of different vegetation types in buffer strips is now renewed. Our experiment used a replicated plot scale facility to compare the efficacy of 12 m wide buffer strips for controlling runoff and suspended sediment loss during 15 sampled storms spanning 2017-2020. The buffer strips comprised three vegetation treatments: a deep rooting grass ( cv. Prior), a short rotation coppice willow and native broadleaved woodland trees. Over the duration of the monitoring period, reductions in total runoff, compared with the experimental control, were in the order: willow buffer strips (49%); deciduous woodland buffer strips (46%); grass buffer strips (33%). The corresponding reductions in suspended sediment loss, relative to the experimental control, were ordered: willow buffer strips (44%) > deciduous woodland buffer strips (30%) > grass buffer strips (29%). Given the 3-year duration of our new dataset, our results should be seen as providing evidence on the impacts during the establishment phase of the treatments.
PubMed: 36636488
DOI: 10.1002/hyp.14733 -
Biosensors Nov 2021We investigated the stability of silver nanoisland films, which were formed on glass surface by the method of out-diffusion, in biocompatible buffers and the...
We investigated the stability of silver nanoisland films, which were formed on glass surface by the method of out-diffusion, in biocompatible buffers and the applicability of the films in surface enhanced Raman scattering (SERS). We have shown that silver nanoisland films are stable in one of the most widespread in biological studies buffer-phosphate buffer saline (PBS), and in 1:100 water-diluted PBS, in the PBS-based buffer, in which NaCl is replaced by the same amount of NaClO, and in acidic phosphate buffer. At the same time, the replacement of NaCl in PBS by N(CH)Cl leads to the degradation of the nanoislands. It was shown that after exposure to PBS the nanoisland films provided a good SERS signal from a monolayer of 1,2-di(4-pyridyl)ethylene (BPE), which makes silver nanoisland films promising for biosensor applications. Additionally, in our experiments, we registered for the first time that silver nanoparticles formed in the bulk of the samples dissolved after exposing to PBS, while nanoislands on the glass surface stayed unchanged. We associate this phenomenon with the interaction of ions contained in PBS solution with silver, which results in the shift of corresponding chemical equilibrium.
Topics: Biocompatible Materials; Buffers; Metal Nanoparticles; Phosphates; Silver; Sodium Chloride; Spectrum Analysis, Raman
PubMed: 34821664
DOI: 10.3390/bios11110448