Project description:PURPOSE:The availability of take home naloxone (THN) was increased for Canadians in 2016, including access to kits via pharmacies. Unlike typical over-the-counter (OTC) and prescription drugs, THN kits may be stored in non-standard conditions, including in vehicles, backpacks, and out of doors. To evaluate whether these non-standard storage conditions affect stability, we investigated the impact of heat and freeze-thaw cycling on naloxone hydrochloride stability. METHODS:To assess the effect of heat, naloxone hydrochloride ampoules were exposed to 80 °C in a temperature-controlled oven for 8 h followed by 16 h at room temperature. To assess the effect of freeze-thaw cycles, naloxone hydrochloride ampoules were exposed to - 20 °C for 16 h followed by 8 h at 4 °C. The impact of these conditions on naloxone hydrochloride stability was evaluated each day for 1 week and after 2 and 4 weeks. The concentration of remaining naloxone hydrochloride was quantified using high-performance liquid chromatography (HPLC). Naloxone hydrochloride ampoules stored at room temperature served as the experimental control. RESULTS:Naloxone hydrochloride ampoules exhibit no changes in drug concentration following exposure to heat or freeze-thaw cycles for up to 28 days compared to ampoules maintained at room temperature (as indicated in the product monograph). CONCLUSIONS:Naloxone hydrochloride remains chemically stable following exposure to heat or freeze-thaw cycles after 28 days. If THN kits are stored in non-standard conditions (for up to 28 days) the active naloxone is likely to remain stable. Despite this, pharmacists should continue to emphasize the importance of appropriate storage of THN kits to ensure optimal efficacy should naloxone administration be required in an emergency situation.
Project description:IntroductionFreeze-thaw instability may contribute to preanalytical variation in blood-based biomarker studies. We investigated the effects of up to four freeze-thaw cycles on single molecule array immunoassays of serum neurofilament light chain and plasma total tau, amyloid β 1-40 (Aß40), and Aβ 1-42 (Aβ42).MethodsIndividuals who had peripheral venepuncture during investigation of suspected neurodegenerative disease were recruited. After standardized preprocessing, 200 μL of plasma and serum aliquots were stored at -80°C within 60 minutes. Aliquots underwent one to four freeze-thaw cycles.ResultsThere was no significant difference across four freeze-thaw cycles for serum neurofilament light chain (n = 12), plasma total tau (n = 11), or plasma Aβ42 (n = 12). For plasma Aβ40 (n = 14), there were significant median reductions by ratios of .96 and .92 at the third and fourth cycles, respectively.DiscussionUp to four freeze-thaw cycles do not influence single molecule array blood biomarkers of neurofilament light chain, total tau, or Aβ42, with at most minor reductions in Aβ40.
Project description:Antarctic krill oil (KO) is known for its poor oxidative stability, especially in emulsion systems. In this experiment, a complex of scallop water-soluble protein-resveratrol (SWPs-RES) was mixed with KO to create high internal phase emulsions (HIPEs) with varying RES ratios. The addition of RES led to noticeable conformational changes in SWPs, including fluorescence bursts, alterations in secondary structure, and modifications in binding motifs. The SWPs-RES complex (1:0.2) demonstrated the most effective free radical scavenging activities (HO: 38.61%, DPPH: 72.49%, ABTS: 85.66%), while the SWPs-RES complex (1:0.025) exhibited the highest emulsifying capacity. Furthermore, HIPEs containing the SWPs-RES complex (1:0.2) displayed improved rheological properties, physical stability, and enhanced oxidative stability against lipid oxidation during storage and simulated in vitro digestion. This study lays a scientific foundation for the utilization of scallop protein and Antarctic krill oil in the food industry.
Project description:3D-printing (3DP) technology has been developing rapidly. However, limited studies on the contribution of 3DP technology, especially multimaterial 3DP technology, to droplet-microfluidics have been reported. In this paper, multimaterial 3D-printed devices for the pneumatic control of emulsion generation have been reported. A 3D coaxial flexible channel with other rigid structures has been designed and printed monolithically. Numerical and experimental studies have demonstrated that this flexible channel can be excited by the air pressure and then deform in a controllable way, which can provide the active control of droplet generation. Furthermore, a novel modular microfluidic device for double emulsion generation has been designed and fabricated, which consists of three modules: function module, T-junction module, and co-flow module. The function module can be replaced by (1) Single-inlet module, (2) Pneumatic Control Unit (PCU) module and (3) Dual-inlet module. Different modules can be easily assembled for different double emulsion production. By using the PCU module, double emulsions with different number of inner droplets have been successfully produced without complicated operation of flow rates of different phases. By using single and dual inlet module, various double emulsions with different number of encapsulated droplets or encapsulated droplets with different compositions have been successfully produced, respectively.
Project description:The feasible application of additive manufacturing in the food and pharmaceutical industries strongly depends on the development of highly stable inks with bioactive properties. Surface-modified microcrystalline cellulose (MCC) shows the potential of being a useful particulate (i.e., Pickering)-type emulsifier to stabilize emulsions. To attain desired therapeutic properties, MCC can also be tuned with cationic antimicrobial compounds to fabricate an antimicrobial printable ink. However, due to the formation of complex coacervates between the two, the Pickering emulsion is very susceptible to phase separation with an insufficient therapeutic effect. To address this drawback, we reported a green method to produce antioxidant and antimicrobial three-dimensional (3D)-printed objects, illustrated here using a printable ink based on a soy-based particulate-type emulsion gel stabilized by a surface-active MCC conjugate (micro-biosurfactant). A sustainable method for the modification of MCC is investigated by grafting gallic acid onto the MCC backbone, followed by in situ reacting via lauric arginate through Schiff-base formation and/or Michael-type addition. Our results show that the grafted micro-biosurfactant was more efficient in providing the necessary physical stability of soy-based emulsion gel. The grafted micro-biosurfactant produced a multifunctional ink with viscoelastic behavior, thixotropic property, and outstanding bioactivities. Following the 3D printing process, highly porous 3D structures with a more precise geometry were fabricated after addition of the micro-biosurfactant. Dynamic sensory evaluation showed that the micro-biosurfactant has a remarkable ability to improve the temporal perceptions of fibrousness and juiciness in printed meat analogue. The results of this study showed the possibility of the development of a therapeutic 3D-printed meat analogue with desired sensory properties, conceiving it as a promising meat analogue product.
Project description:In this study, the effects of the addition of pectin (PEC) on the physicochemical properties and freeze-thaw stability of waxy rice starch (WRS) were investigated. As PEC content increased, the pasting viscosity and pasting temperature of WRS significantly increased (p < 0.05), whereas its breakdown value and setback value decreased. Differential scanning calorimetry showed that the addition of PEC increased the gelatinization temperature of WRS, but decreased its gelatinization enthalpy. Rheological measurements indicated that the addition of PEC did not change the shear-thinning behavior of WRS-PEC blends, and the storage modulus and loss modulus were positively correlated with PEC content. Moreover, the textural parameter of WRS decreased with the increase in PEC content. Furthermore, the addition of PEC decreased the transmittance of starch paste, but enhanced the freeze-thaw stability of WRS to some extent. These results may contribute to the development of WRS-based food products.
Project description:The importance of studying the structural stability of proteins is determined by the structure-function relationship. Protein stability is influenced by many factors among which are freeze-thaw and thermal stresses. The effect of trehalose, betaine, sorbitol and 2-hydroxypropyl-β-cyclodextrin (HPCD) on the stability and aggregation of bovine liver glutamate dehydrogenase (GDH) upon heating at 50 °C or freeze-thawing was studied by dynamic light scattering, differential scanning calorimetry, analytical ultracentrifugation and circular dichroism spectroscopy. A freeze-thaw cycle resulted in the complete loss of the secondary and tertiary structure, and aggregation of GDH. All the cosolutes suppressed freeze-thaw- and heat-induced aggregation of GDH and increased the protein thermal stability. The effective concentrations of the cosolutes during freeze-thawing were lower than during heating. Sorbitol exhibited the highest anti-aggregation activity under freeze-thaw stress, whereas the most effective agents stabilizing the tertiary structure of GDH were HPCD and betaine. HPCD and trehalose were the most effective agents suppressing GDH thermal aggregation. All the chemical chaperones stabilized various soluble oligomeric forms of GDH against both types of stress. The data on GDH were compared with the effects of the same cosolutes on glycogen phosphorylase b during thermal and freeze-thaw-induced aggregation. This research can find further application in biotechnology and pharmaceutics.
Project description:DNA computing harnesses the immense potential of DNA molecules to enable sophisticated and transformative computational processes but is hindered by low computing speed. Here, we propose freeze-thaw cycling as a simple yet powerful method for high-speed DNA computing without complex procedures. Through iterative cycles, we achieve a substantial 20-fold speed enhancement in basic strand displacement reactions. This acceleration arises from the utilization of eutectic ice phase as a medium, temporarily increasing the effective local concentration of molecules during each cycle. In addition, the acceleration effect follows the Hofmeister series, where kosmotropic anions such as sulfate (SO42-) reduce eutectic phase volume, leading to a more notable enhancement in strand displacement reaction rates. Leveraging this phenomenon, freeze-thaw cycling demonstrates its generalizability for high-speed DNA computing across various circuit sizes, achieving up to a remarkable 120-fold enhancement in reaction rates. We envision its potential to revolutionize molecular computing and expand computational applications in diverse fields.
Project description:Tissues are organized in hierarchical structures comprised of nanoscale, microscale, and macroscale features. Incorporating hierarchical structures into biomaterial scaffolds may enable better resemblance of native tissue structures and improve cell interaction, but it is challenging to produce such scaffolds using a single conventional scaffold production technique. We developed the Freeze-FRESH (FF) technique that combines FRESH 3D printing (3DP) and freeze-casting to produce 3D printed scaffolds with microscale pores in the struts. FF scaffolds were produced by extrusion 3DP using a support bath at room temperature, followed by freezing and lyophilization, then the FF scaffolds were recovered from the bath and crosslinked. The FF scaffolds had a hierarchical pore structure from the combination of microscale pores throughout the scaffold struts and macroscale pores in the printed design, while control scaffolds had only macroscale pores. FF scaffolds frozen at -20 °C and -80 °C had similar pore sizes, due to freezing in the support bath. The -20 °C and -80 °C FF scaffolds had porous struts with 63.55% ± 2.59% and 56.72% ± 13.17% strut porosity, respectively, while control scaffolds had a strut porosity of 3.15% ± 2.20%. The -20 °C and -80 °C FF scaffolds were softer than control scaffolds: they had pore wall stiffness of 0.17 ± 0.06 MPa and 0.23 ± 0.05 MPa, respectively, compared to 1.31 ± 0.39 MPa for the control. The FF scaffolds had increased resilience in bending compared with control. FF scaffolds supported MDA-MB-231 cell growth and had significantly greater cell numbers than control scaffolds. Cells formed clusters on the porous struts of FF scaffolds and had similar morphologies as the freeze cast scaffolds. The FF technique successfully introduced microscale porosity into the 3DP scaffold struts to produce hierarchical pore structures that enhanced MDA-MB-231 growth.