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International Journal of Pharmaceutics Apr 2024A core-sheath structure is one of the methods developed to overcome the challenges often faced when using monolithic fibers for drug delivery. In this study, fibers...
A core-sheath structure is one of the methods developed to overcome the challenges often faced when using monolithic fibers for drug delivery. In this study, fibers based on polyvinylpyrrolidone (core) and ethyl cellulose (sheath) were successfully produced using a novel core-sheath pressure-spinning process. For comparison, these two polymers were also processed into as blend fibers. All samples were then investigated for their performances in releasing water-soluble ampicillin (AMP) and poorly water-soluble ibuprofen (IBU) model drugs. Scanning electron,digital and confocal microscopy confirmed that fibers with a core-sheath structure were successfully made. Fourier transform infrared spectroscopy showed the success of the pressure-spinning technique in encapsulating AMP/IBU in all fiber samples. Compared to blend fibers, the core-sheath fibers had better performance in encapsulating both water-soluble and poorly water-soluble drugs. Moreover, the core-sheath structure was able to reduce the initial burst release and provided a better sustained release profile than the blend fiber analog. In conclusion, the pressure-spinning method was capable of producing core-sheath and blend fibers that could be used for the loading of either hydrophilic or hydrophobic drugs for controlled drug delivery systems.
Topics: Povidone; Drug Liberation; Drug Delivery Systems; Pharmaceutical Preparations; Water; Nanofibers; Cellulose
PubMed: 38458404
DOI: 10.1016/j.ijpharm.2024.123972 -
International Journal of Pharmaceutics Apr 2024The oral bioavailability of paclitaxel is limited due to low solubility and high affinity for the P-glycoprotein (P-gp) efflux transporter. Here we hypothesized that...
The oral bioavailability of paclitaxel is limited due to low solubility and high affinity for the P-glycoprotein (P-gp) efflux transporter. Here we hypothesized that maximizing the intestinal paclitaxel levels through apparent solubility enhancement and controlling thesimultaneous release of both paclitaxel and the P-gp inhibitor encequidar from amorphous solid dispersions (ASDs) would increase the oral bioavailability of paclitaxel. ASDs of paclitaxel and encequidar in polyvinylpyrrolidone K30 (PVP-K30), hydroxypropylmethylcellulose 5 (HPMC-5), and hydroxypropylmethylcellulose 4 K (HPMC-4K) were hence prepared by freeze-drying. In vitro dissolution studies showed that both compounds were released fastest from PVP-K30, then from HPMC-5, and slowest from HPMC-4K ASDs. The dissolution of paclitaxel from all polymers resulted in stable concentration levels above the apparent solubility. The pharmacokinetics of paclitaxel after oral administration to male Sprague-Dawley rats was investigated with or without 1 mg/kg encequidar, as amorphous solids or polymer-based ASDs. The bioavailability of paclitaxel increased 3- to 4-fold when administered as polymer-based ASDs relative to solid amorphous paclitaxel. However, when amorphous paclitaxel was co-administered with encequidar, either as an amorphous powder or as a polymer-based ASD, the bioavailability increased 2- to 4-fold, respectively. Interestingly, a noticeable increase in paclitaxel bioavailability of 24-fold was observed when paclitaxel and encequidar were co-administered as HPMC-5-based ASDs. We, therefore, suggest that controlling the dissolution rate of paclitaxel and encequidar in order to obtain simultaneous and timed release from polymer-based ASDs is a strategy to increase oral paclitaxel bioavailability.
Topics: Rats; Male; Animals; Biological Availability; Rats, Sprague-Dawley; Hypromellose Derivatives; Solubility; Polymers; Povidone
PubMed: 38442796
DOI: 10.1016/j.ijpharm.2024.123965 -
World Journal of Microbiology &... Feb 2024Six lactic acid bacteria (LAB) isolated from Algerian sheep's milk, traditional butter, date palm sap and barley, which produce dextran, mannitol, oligosaccharides and...
Leuconostoc mesenteroides and Liquorilactobacillus mali strains, isolated from Algerian food products, are producers of the postbiotic compounds dextran, oligosaccharides and mannitol.
Six lactic acid bacteria (LAB) isolated from Algerian sheep's milk, traditional butter, date palm sap and barley, which produce dextran, mannitol, oligosaccharides and vitamin B have been characterized. They were identified as Leuconostoc mesenteroides (A4X, Z36P, B12 and O9) and Liquorilactobacillus mali (BR201 and FR123). Their exopolysaccharides synthesized from sucrose by dextransucrase (Dsr) were characterized as dextrans with (1,6)-D-glucopyranose units in the main backbone and branched at positions O-4, O-2 and/or O-3, with D-glucopyranose units in the side chain. A4X was the best dextran producer (4.5 g/L), while the other strains synthesized 2.1-2.7 g/L. Zymograms revealed that L. mali strains have a single Dsr with a molecular weight (Mw) of ~ 145 kDa, while the Lc. mesenteroides possess one or two enzymes with 170-211 kDa Mw. As far as we know, this is the first detection of L. mali Dsr. Analysis of metabolic fluxes from sucrose revealed that the six LAB produced mannitol (~ 12 g/L). The co-addition of maltose-sucrose resulted in the production of panose (up to 37.53 mM), an oligosaccharide known for its prebiotic effect. A4X, Z36P and B12 showed dextranase hydrolytic enzymatic activity and were able to produce another trisaccharide, maltotriose, which is the first instance of a dextranase activity encoded by Lc. mesenteroides strains. Furthermore, B12 and O9 grew in the absence of riboflavin (vitamin B) and synthesized this vitamin, in a defined medium at the level of ~ 220 μg/L. Therefore, these LAB, especially Lc. mesenteroides B12, are good candidates for the development of new fermented food biofortified with functional compounds.
Topics: Animals; Sheep; Leuconostoc mesenteroides; Dextrans; Dextranase; Mannitol; Mali; Glucosyltransferases; Oligosaccharides; Sucrose; Vitamins; Leuconostoc
PubMed: 38418710
DOI: 10.1007/s11274-024-03913-3 -
ACS Applied Bio Materials Mar 2024The growing concerns regarding foodborne illnesses related to fresh produce accentuate the necessity for innovative material solutions, particularly on surfaces that...
The growing concerns regarding foodborne illnesses related to fresh produce accentuate the necessity for innovative material solutions, particularly on surfaces that come into close contact with foods. This study introduces a sustainable, efficient, and removable antimicrobial and antifouling coating ideally suited for hydrophobic food-contact surfaces such as low-density polyethylene (LDPE). Developed through a crosslinking reaction involving tannic acid, gelatin, and soy protein hydrolysate, these coatings exhibit proper stability in aqueous washing solutions and effectively combat bacterial contamination and prevent biofilm formation. The unique surface architecture promotes the formation of halamine structures, enhancing antimicrobial efficacy with a rapid contact killing effect and reducing microbial contamination by up to 5 log cfu·cm against both (Gram-negative) and (Gram-positive). Notably, the coatings are designed for at least five recharging cycles under mild conditions (pH6, 20 ppm free active chlorine) and can be easily removed with hot water or steam to refresh the depositions. This removal process not only conveniently aligns with existing sanitation protocols in the fresh produce industry but also facilitates the complete eradication of potential developed biofilms, outperforming uncoated LDPE coupons. Overall, these coatings represent sustainable, cost-effective, and practical advancements in food safety and are promising candidates for widespread adoption in food processing environments.
Topics: Biofouling; Polyethylene; Anti-Infective Agents; Povidone; Escherichia coli; Polyphenols
PubMed: 38416807
DOI: 10.1021/acsabm.3c01247 -
International Journal of Molecular... Feb 2024The results of the synthesis of microcrystalline calcium phosphates such as hydroxoapatite, pyrophosphate, and tricalcium phosphate are presented herein. The influence...
The results of the synthesis of microcrystalline calcium phosphates such as hydroxoapatite, pyrophosphate, and tricalcium phosphate are presented herein. The influence of the addition of polyvinylpyrrolidone (PVP) on the phase characteristics of the resulting high-temperature ceramic sample is considered. The X-ray results show that hydroxyapatite (HAp) consists of a Ca(PO)(OH) phase, while the sample with the addition of polyvinylpyrrolidone contains β-Ca(PO) (65.5%) and β-CaPO (34.5%) phases calcium phosphates (CPs). IR spectroscopy was used to characterize the compositions of the samples. An important characteristic of the obtained samples is the elemental Ca/P ratio, which was determined via energy-dispersive analysis. The data obtained are consistent with the composition of dental enamel apatites, namely, in the CPs (1.27) and HAp (1.40). SEM was used to study the morphology of the surfaces of hydroxyapatite particles. Polyvinylpyrrolidone polymer fibers were obtained using the electroforming method with the inclusion of CPs in the composition. The fibers were oriented randomly, and nanoscale hydroxyapatite particles were incorporated into the fiber structure. Solubility data of the HAp, CPs, and Fibers in a physiological solution at room temperature and human body temperature were obtained. The solubility of the resulting HAp turned out to be higher than the solubility of the CPs. In turn, the concentration of Ca in a physiological solution of PVP composite fibers with the inclusion of CPs was lower than that in powdered CPs.
Topics: Humans; Phosphates; Povidone; Temperature; Calcium Phosphates; Durapatite; Apatites; X-Ray Diffraction
PubMed: 38396975
DOI: 10.3390/ijms25042298 -
PloS One 2024Glipizide, a poor water-soluble drug belongs to BCS class II. The proposed work aimed to enhance the solubility of glipizide by preparing solid dispersions, using...
Glipizide, a poor water-soluble drug belongs to BCS class II. The proposed work aimed to enhance the solubility of glipizide by preparing solid dispersions, using polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG). Solvent evaporation method was used for the preparation of glipizide solid dispersions. Solid dispersions were prepared in four different drug-to-polymer ratios i.e. 1:1, 1:2, 1:3 and 1:4. Mainly effect of three polymers (PVP K30, PVP K90 and PEG 6000) was evaluated on the solubility and dissolution of glipizide. The in-vitro dissolution of all prepared formulations was performed under pH 6.8 at 37°C using USP type II apparatus. In-vitro dissolution results revealed that the formulations having high concentrations of the polymer showed enhanced solubility. Enhancements in the solubility and rate of dissolution of the drug were noted in solid dispersion formulations compared to the physical blends and pure drug. Solid dispersions containing polyvinyl pyrrolidone exhibited a more favorable pattern of drug release compared to the corresponding solid dispersions with PEG. An increase in the maximum solubility of the drug within the solid dispersion systems was observed in all instances. Two solid dispersion formulations were optimized and formulated into immediate-release tablets, which passed all the pharmacopoeial and non-pharmacopoeial tests. Fourier transformed Infrared (FTIR) spectroscopy X-ray diffraction (XRD) and Differential scanning calorimetry (DSC) were used to indicate drug: polymer interactions in solid state. Analysis of the solid dispersion samples through characterization tests indicated the compatibility between the drug and the polymer.
Topics: Solubility; Glipizide; Polyvinyls; Polymers; Polyethylene Glycols; Spectroscopy, Fourier Transform Infrared; Povidone; X-Ray Diffraction; Calorimetry, Differential Scanning
PubMed: 38394326
DOI: 10.1371/journal.pone.0297467 -
Marine Drugs Jan 2024In this study, an actinomycete was isolated from sea mud. The strain K1 was identified as sp. by 16S rDNA. The optimal enzyme production temperature, initial pH, time,...
In this study, an actinomycete was isolated from sea mud. The strain K1 was identified as sp. by 16S rDNA. The optimal enzyme production temperature, initial pH, time, and concentration of the inducer of this actinomycete strain K1 were 37 °C, pH 8.5, 72 h, and 2% dextran T20 of medium, respectively. Dextranase from strain K1 exhibited maximum activity at 8.5 pH and 50 °C. The molecular weight of the enzyme was <10 kDa. The metal ions Sr and enhanced its activity, whereas Fe and Co had an opposite effect. In addition, high-performance liquid chromatography showed that dextran was mainly hydrolyzed to isomaltoheptose and isomaltopentaose. Also, it could effectively remove biofilms of . Furthermore, it could be used to prepare porous sweet potato starch. This is the first time a dextranase-producing actinomycete strain was screened from marine samples.
Topics: Dextrans; Dextranase; Hydrogen-Ion Concentration; Biofilms; Actinobacteria
PubMed: 38393040
DOI: 10.3390/md22020069 -
MBio Mar 2024The human colon hosts hundreds of commensal bacterial species, many of which ferment complex dietary carbohydrates. To transform these fibers into metabolically...
UNLABELLED
The human colon hosts hundreds of commensal bacterial species, many of which ferment complex dietary carbohydrates. To transform these fibers into metabolically accessible compounds, microbes often express a series of dedicated enzymes homologous to the starch utilization system (Sus) encoded in polysaccharide utilization loci (PULs). The genome of (), a common member of the human gut microbiota, encodes nearly 100 PULs, conferring a strong metabolic versatility. While the structures and functions of individual enzymes within the PULs have been investigated, little is known about how polysaccharide complexity impacts the function of Sus-like systems. We here show that the activity of Sus-like systems depends on polysaccharide size, ultimately impacting bacterial growth. We demonstrate the effect of size-dependent metabolism in the context of dextran metabolism driven by the specific utilization system PUL48. We find that as the molecular weight of dextran increases, growth rate decreases and lag time increases. At the enzymatic level, the dextranase BT3087, a glycoside hydrolase (GH) belonging to the GH family 66, is the main GH for dextran utilization, and BT3087 and BT3088 contribute to dextran metabolism in a size-dependent manner. Finally, we show that the polysaccharide size-dependent metabolism of impacts its metabolic output in a way that modulates the composition of a producer-consumer community it forms with . Altogether, our results expose an overlooked aspect of metabolism that can impact the composition and diversity of microbiota.
IMPORTANCE
Polysaccharides are complex molecules that are commonly found in our diet. While humans lack the ability to degrade many polysaccharides, their intestinal microbiota contain bacterial commensals that are versatile polysaccharide utilizers. The gut commensal dedicates roughly 20% of their genomes to the expression of polysaccharide utilization loci for the broad range utilization of polysaccharides. Although it is known that different polysaccharide utilization loci are dedicated to the degradation of specific polysaccharides with unique glycosidic linkages and monosaccharide compositions, it is often overlooked that specific polysaccharides may also exist in various molecular weights. These different physical attributes may impact their processability by starch utilization system-like systems, leading to differing growth rates and nutrient-sharing properties at the community level. Therefore, understanding how molecular weight impacts utilization by gut microbe may lead to the potential design of novel precision prebiotics.
Topics: Humans; Bacteroides thetaiotaomicron; Molecular Weight; Bacteroides; Dextrans; Gastrointestinal Tract; Polysaccharides; Starch
PubMed: 38376161
DOI: 10.1128/mbio.02599-23 -
PloS One 2024Perioperative anaesthesia management has an important significance for kidney transplantation; however, the related consensus remains limited. An electronic survey with...
Perioperative anaesthesia management has an important significance for kidney transplantation; however, the related consensus remains limited. An electronic survey with 44 questions was developed and sent to the chief anaesthesiologist at 115 non-military medical centres performing kidney transplantation in China through WeChat. A response rate of 81.7% was achieved from 94 of 115 non-military medical centres, where 94.4% of kidney transplants (10404 /11026) were completed in 2021. The result showed an overview of perioperative practice for kidney transplantations in China, identify the heterogeneity, and provide evidence for improving perioperative management of kidney transplantation. Some controversial therapy, such as hydroxyethyl starch, are still widely used, while some recommended methods are not widely available. More efforts on fluid management, hemodynamical monitoring, perioperative anaesthetics, and postoperative pain control are needed to improve the outcomes. Evidence-based guidelines for standardizing clinical practice are needed.
Topics: Humans; Kidney Transplantation; Anesthetics; Surveys and Questionnaires; Hydroxyethyl Starch Derivatives; Postoperative Complications; Perioperative Care
PubMed: 38354172
DOI: 10.1371/journal.pone.0298051 -
Cryobiology Jun 2024The cryopreservation of endothelial cell monolayers is an important step that bridges the cryopreservation of cells in suspension to that of tissues. Previous studies...
The cryopreservation of endothelial cell monolayers is an important step that bridges the cryopreservation of cells in suspension to that of tissues. Previous studies have identified clear distinctions in freezing mechanisms between cells in suspension and in monolayers, as well as developed novel protocols for monolayer cryopreservation. Recently, our group has shown that human umbilical vein endothelial cell (HUVEC) and porcine corneal endothelial cell (PCEC) monolayers grown on Rinzl plastic substrate can be cryopreserved in 5% dimethyl sulfoxide, 6% hydroxyethyl starch, and 2% chondroitin sulfate, following a slow-cooling protocol (-1 °C/min) with rapid plunge into liquid nitrogen from -40 °C. However, membrane integrity assessments were done immediately post thaw, which may result in an overestimation of cell viability due to possible delayed injury responses. Here, we show that for the optimal protocol condition of plunge at the -40 °C interrupt temperature, HUVEC and PCEC monolayers exhibited no significant immediate post-thaw injuries nor delayed injury responses during the 24-h post-thaw overnight culture period. HUVEC monolayers experienced no significant impact to their natural growth rate during the post-thaw culture, while PCEC monolayers experienced significantly higher growth than the unfrozen controls. The difference in the low-temperature responses between HUVEC and PCEC monolayers was further shown under high temperature plunge conditions. At these suboptimal plunge temperatures, HUVEC monolayers exhibited moderate immediate membrane injury but a pronounced delayed injury response during the 24-h post-thaw culture, while PCEC monolayers showed significant immediate membrane injury but no additional delayed injury response during the same period. Therefore, we provide further validation of our group's previously designed endothelial monolayer cryopreservation protocol for HUVEC and PCEC monolayers, and we identify several cell-type-specific responses to the freezing process.
Topics: Cryopreservation; Humans; Human Umbilical Vein Endothelial Cells; Animals; Cell Survival; Cryoprotective Agents; Swine; Dimethyl Sulfoxide; Chondroitin Sulfates; Endothelial Cells; Hydroxyethyl Starch Derivatives; Cells, Cultured; Endothelium, Corneal
PubMed: 38350589
DOI: 10.1016/j.cryobiol.2024.104857