28 research outputs found
Zein-based nanospheres and nanocapsules for the encapsulation and oral delivery of quercetin
In this study, the ability of zein nanospheres (NS) and zein nanocapsules containing wheat germ oil (NC) to
enhance the bioavailability and efficacy of quercetin was evaluated. Both types of nanocarriers had similar
physico-chemical properties, including size (between 230 and 250 nm), spherical shape, negative zeta potential,
and surface hydrophobicity. However, NS displayed a higher ability than NC to interact with the intestinal
epithelium, as evidenced by an oral biodistribution study in rats. Moreover, both types of nanocarriers offered
similar loading efficiencies and release profiles in simulated fluids. In C. elegans, the encapsulation of quercetin in
nanospheres (Q-NS) was found to be two twice more effective than the free form of quercetin in reducing lipid
accumulation. For nanocapsules, the presence of wheat germ oil significantly increased the storage of lipids in
C. elegans; although the incorporation of quercetin (Q-NC) significantly counteracted the presence of the oil.
Finally, nanoparticles improved the oral absorption of quercetin in Wistar rats, offering a relative oral
bioavailability of 26% and 57% for Q-NS and Q-NC, respectively, compared to a 5% for the control formulation.
Overall, the study suggests that zein nanocarriers, particularly nanospheres, could be useful in improving the
bioavailability and efficacy of quercetin
Modulation of the fate of zein nanoparticles by their coating with a Gantrez® AN-thiamine polymer conjugate
The aim of this work was to evaluate the mucus-permeating properties of nanocarriers using zein nanoparticles
(NPZ) coated with a Gantrez® AN-thiamine conjugate (GT). NPZ were coated by incubation at different GT-tozein ratios: 2.5% coating with GT (GT-NPZ1), 5% (GT-NPZ2) and 10% (GT-NPZ3). During the process, the GT
conjugate formed a polymer layer around the surface of zein nanoparticles. For GT-NPZ2, the thickness of this
corona was estimated between 15 and 20 nm. These nanocarriers displayed a more negative zeta potential than
uncoated NPZ. The diffusivity of nanoparticles was evaluated in pig intestinal mucus by multiple particle
tracking analysis. GT-NPZ2 displayed a 28-fold higher diffusion coefficient within the mucus layer than NPZ
particles. These results align with in vivo biodistribution studies in which NPZ displayed a localisation restricted
to the mucus layer, whereas GT-NPZ2 were capable of reaching the intestinal epithelium. The gastro-intestinal
transit of mucoadhesive (NPZ) and mucus-permeating nanoparticles (GT-NPZ2) was also found to be different.
Thus, mucoadhesive nanoparticles displayed a significant accumulation in the stomach of animals, whereas
mucus-penetrating nanoparticles appeared to exit the stomach more rapidly to access the small intestine of
animal
Encapsulation of Lactobacillus plantarum in casein-chitosan microparticles facilitates the arrival to the colon and develops an immunomodulatory effect
The current work describes the capability of casein-chitosan microparticles to encapsulate Lactobacillus plantarum
(CECT 220 and WCFS1 strains) and evaluates their ability to target the distal areas of the gut and to stimulate the
immune system. Microparticles were prepared by complex coacervation, between sodium caseinate and chitosan
in an aqueous suspension of the bacteria, and dried by spray-drying. In order to increase the survival rate of the
loaded bacteria, microparticles were cross-linked with one of the following cross-linkers: tripolyphosphate,
calcium salts or vanillin.
Overall, microparticles displayed a mean size of about 7.5 μm with a bacteria loading of about 11 Log CFU/g,
when cross-linked with vanillin (MP-LP-V). For conventional microparticles, the payload was 10.12 Log CFU/g.
The storage stability study at 25 ◦C/60% RH, MP-LP-V offered the highest degree of protection without signif-
icant modification of the payload in 260 days. Compared with control (aqueous suspension of bacteria), MP-LP-V
also displayed a significantly higher degree of protection against probiotic inactivation in simulated gastric and
intestinal fluids. In vivo results evidenced that microparticles, orally administered to rats, were able to reach the
distal ileum and colon in about 4 h post-administration. Additionally, the effect of the daily administration of
107 CFU/mouse of MP-LP-V, for 3 weeks, induced an immunomodulatory effect characterized by an important
enhancement of Th1 and Th17 responses. In conclusion, these microparticles seem to be a promising strategy for
increasing survival and efficacy of probiotics, allowing the formulation of cost-effective and more stable and
effective probiotic-based nutraceuticals
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The effect of thiamine-coating nanoparticles on their biodistribution and fate following oral administration
Thiamine-coated nanoparticles were prepared by two different preparative methods and evaluated to compare their mucus-penetrating properties and fate in vivo. The first method of preparation consisted of surface modification of freshly poly(anhydride) nanoparticles (NP) by simple incubation with thiamine (T-NPA). The second procedure focused on the preparation and characterization of a new polymeric conjugate between the poly(anhydride) backbone and thiamine prior the nanoparticle formation (T-NPB). The resulting nanoparticles displayed comparable sizes (about 200 nm) and slightly negative surface charges. For T-NPA, the amount of thiamine associated to the surface of the nanoparticles was 15 µg/mg. For in vivo studies, nanoparticles were labeled with either 99mTc or Lumogen® Red. T-NPA and T-NPB moved faster from the stomach to the small intestine than naked nanoparticles. Two hours post-administration, for T-NPA and T-NPB, more than 30% of the given dose was found in close contact with the intestinal mucosa, compared with a 13.5% for NP. Interestingly, both types of thiamine-coated nanoparticles showed a greater ability to cross the mucus layer and interact with the surface of the intestinal epithelium than NP, which remained adhered in the mucus layer. Four hours post-administration, around 35% of T-NPA and T-NPB were localized in the ileum of animals. Overall, both preparative processes yielded thiamine decorated carriers with similar physico-chemical and biodistribution properties, increasing the versatility of these nanocarriers as oral delivery systems for a number of biologically active compounds
The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients
Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation
Assessing fish metrics and biotic indices in a Mediterranean stream: effects of uncertain native status of fish
Modulation of the fate of zein nanoparticles by their coating with a Gantrez® AN-thiamine polymer conjugate
The aim of this work was to evaluate the mucus-permeating properties of nanocarriers using zein nanoparticles
(NPZ) coated with a Gantrez® AN-thiamine conjugate (GT). NPZ were coated by incubation at different GT-tozein ratios: 2.5% coating with GT (GT-NPZ1), 5% (GT-NPZ2) and 10% (GT-NPZ3). During the process, the GT
conjugate formed a polymer layer around the surface of zein nanoparticles. For GT-NPZ2, the thickness of this
corona was estimated between 15 and 20 nm. These nanocarriers displayed a more negative zeta potential than
uncoated NPZ. The diffusivity of nanoparticles was evaluated in pig intestinal mucus by multiple particle
tracking analysis. GT-NPZ2 displayed a 28-fold higher diffusion coefficient within the mucus layer than NPZ
particles. These results align with in vivo biodistribution studies in which NPZ displayed a localisation restricted
to the mucus layer, whereas GT-NPZ2 were capable of reaching the intestinal epithelium. The gastro-intestinal
transit of mucoadhesive (NPZ) and mucus-permeating nanoparticles (GT-NPZ2) was also found to be different.
Thus, mucoadhesive nanoparticles displayed a significant accumulation in the stomach of animals, whereas
mucus-penetrating nanoparticles appeared to exit the stomach more rapidly to access the small intestine of
animal
Zein-based nanospheres and nanocapsules for the encapsulation and oral delivery of quercetin
In this study, the ability of zein nanospheres (NS) and zein nanocapsules containing wheat germ oil (NC) to
enhance the bioavailability and efficacy of quercetin was evaluated. Both types of nanocarriers had similar
physico-chemical properties, including size (between 230 and 250 nm), spherical shape, negative zeta potential,
and surface hydrophobicity. However, NS displayed a higher ability than NC to interact with the intestinal
epithelium, as evidenced by an oral biodistribution study in rats. Moreover, both types of nanocarriers offered
similar loading efficiencies and release profiles in simulated fluids. In C. elegans, the encapsulation of quercetin in
nanospheres (Q-NS) was found to be two twice more effective than the free form of quercetin in reducing lipid
accumulation. For nanocapsules, the presence of wheat germ oil significantly increased the storage of lipids in
C. elegans; although the incorporation of quercetin (Q-NC) significantly counteracted the presence of the oil.
Finally, nanoparticles improved the oral absorption of quercetin in Wistar rats, offering a relative oral
bioavailability of 26% and 57% for Q-NS and Q-NC, respectively, compared to a 5% for the control formulation.
Overall, the study suggests that zein nanocarriers, particularly nanospheres, could be useful in improving the
bioavailability and efficacy of quercetin
Encapsulation of Lactobacillus plantarum in casein-chitosan microparticles facilitates the arrival to the colon and develops an immunomodulatory effect
The current work describes the capability of casein-chitosan microparticles to encapsulate Lactobacillus plantarum
(CECT 220 and WCFS1 strains) and evaluates their ability to target the distal areas of the gut and to stimulate the
immune system. Microparticles were prepared by complex coacervation, between sodium caseinate and chitosan
in an aqueous suspension of the bacteria, and dried by spray-drying. In order to increase the survival rate of the
loaded bacteria, microparticles were cross-linked with one of the following cross-linkers: tripolyphosphate,
calcium salts or vanillin.
Overall, microparticles displayed a mean size of about 7.5 μm with a bacteria loading of about 11 Log CFU/g,
when cross-linked with vanillin (MP-LP-V). For conventional microparticles, the payload was 10.12 Log CFU/g.
The storage stability study at 25 ◦C/60% RH, MP-LP-V offered the highest degree of protection without signif-
icant modification of the payload in 260 days. Compared with control (aqueous suspension of bacteria), MP-LP-V
also displayed a significantly higher degree of protection against probiotic inactivation in simulated gastric and
intestinal fluids. In vivo results evidenced that microparticles, orally administered to rats, were able to reach the
distal ileum and colon in about 4 h post-administration. Additionally, the effect of the daily administration of
107 CFU/mouse of MP-LP-V, for 3 weeks, induced an immunomodulatory effect characterized by an important
enhancement of Th1 and Th17 responses. In conclusion, these microparticles seem to be a promising strategy for
increasing survival and efficacy of probiotics, allowing the formulation of cost-effective and more stable and
effective probiotic-based nutraceuticals
Transplantation of adipose derived stromal cells is associated with functional improvement in a rat model of chronic myocardial infarction
Aims: To determine the effect of transplantation of undifferentiated and cardiac pre-differentiated adipose stem cells compared with bone marrow mononuclear cells (BM-MNC) in a chronic model of myocardial infarction.
Methods: Ninety-five Sprague–Dawley rats underwent left coronary artery ligation and after 1month received by direct intramyocardial injection either adipose derived stem cells (ADSC), cardiomyogenic cells (AD-CMG) or BM-MNC from enhanced-Green Fluorescent Protein (eGFP) mice. The control group was treated with culture medium. Heart function was assessed by echocardiography and 18F-FDG microPET. Cell engraftment, differentiation, angiogenesis and fibrosis in the scar tissue were also evaluated by (immuno)histochemistry and immunofluorescence.
Results: One month after cell transplantation, ADSC induced a significant improvement in heart function (LVEF 46.3±9.6% versus 27.7±8% pre-transplant) and tissue viability (64.78±7.2% versus 55.89±6.3% pre-transplant). An increase in the degree of angiogenesis and a decrease in fibrosis were also detected. Although transplantation of AD-CMG or BM-MNC also had a positive, albeit smaller, effect on angiogenesis and fibrosis in the infarcted hearts, this benefit did not translate into a significant improvement in heart function or tissue viability.
Conclusion: These results indicate that transplantation of adipose derived cells in chronic infarct provides a superior benefit to cardiac pre-differentiated ADSC and BM-MNC