March 2, 2024

Sustained transdermal delivery of human growth hormone from niosomal gel: in vitro and in vivo studies

Human growth hormone (hGH) is widely used to treat several diseases for decades. However, the current treatment regime requires frequent injections via subcutaneous route due to short in vivo half-life, which leads to pain and poor patient compliance. In this study, a novel transdermal (non-invasive) hGH loaded niosomes gel was prepared to reduce the frequency of subcutaneous injections and to improve the patient compliance. Niosomes were prepared by film hydration technique at three levels of cholesterol. The particle size and entrapment efficiency increases with an increase in the level of cholesterol. Transmission electron microscopy images confirmed the spherical shape of niosomes without aggregation.
Texture profiles analysis indicates that the niosomal gel has the required mechanical properties for transdermal application. The ex vivo permeation profile showed sustain hGH release for 4 days from the niosomal gel compared to 24 h from the control gel without niosomes. A rabbit skin irritation study showed no sign of irritation after application of niosomal gel. The pharmacokinetic parameters in the rat model showed 7.22-fold higher bioavailability with niosomal gel compared to control gel. In conclusion, the study demonstrated the potential of niosomal gel as an effective long-term sustained release strategy for hGH delivery to replace traditional subcutaneous injections.

Hydrodynamics induce superdiffusive jumps of passive tracers along critical paths of random networks and colloidal gels

We present a numerical study on the effect of hydrodynamic interactions (HI) on the diffusion of inert point tracer particles in several fixed random structures. As expected, the diffusion is hampered by the extra hydrodynamic friction introduced by the obstacle network. However, a non-trivial effect due to HI appears in the analysis of the van-Hove displacement probability close to the percolation threshold, where tracers diffuse through critical fractal paths. We show that the tracer dynamics can be split up into short and long jumps, the latter being ruled by either exponential or Gaussian van Hove distribution tails. While at short time HI slow down the tracer diffusion, at long times, hydrodynamic interactions with the obstacles increase the probability of longer jumps, which circumvent the traps of the labyrinth more easily.
Notably, the relation between the anomalous diffusion exponent and the fractal dimension of the critical (intricate) paths is greater than one, which implies that the long-time (long-jump) diffusion is mildly superdiffuse. A possible reason for such a hastening of the diffusion along the network corridors is the hydrodynamically induced mobility anisotropy, which favours displacements parallel to the walls, an effect which has already been experimentally observed in collagen gels.

Study on the texture properties and oxidation characteristics of egg yolk powder gel

The gel was prepared by thermal induction of egg yolk powder as raw material in this study. Firstly, the lipid component of egg yolk powder gel and the correlation between the gel strength of egg yolk powder and Texture Profile Analysis were analyzed, and then the changes of oxidation products. The method of principal component analysis (PCA) was used to determine the relationship between secondary oxidation products and fatty acids content. Moreover, Redundancy analysis (RDA) was used to study the relationship between fatty acids, Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), peroxide value (POV) in Egg Yolk Gel. Result indicated, Lipid content of egg yolk powder gel was lower than egg yolk powder, the gel strength was positively correlated with hardness, adhesion, viscosity and masticatory (p < 0.01), and had a significant negative correlation with recovery (p < 0.01).
In the nuclear magnetic map, the signal of primary oxidation product E, E-conjugate form was at 5.70 ppm, the signal of secondary oxidation product n-aldehyde was at 9.75 ppm. Combined with PCA and RDA, the results showed that the changes of fatty acid content were negatively correlated with the changes of peroxide value, while the changes of PC and PE were positively correlated, and the contents of fatty acids, PE, PI and PC were negatively correlated with the changes of POV, of which PE and POV were the most correlated.

The Outcomes of XEN Gel Stent Implantation: A Systematic Review and Meta-Analysis

Purpose: XEN gel stents are used for the treatment of open-angle glaucoma (OAG), including primary and secondary glaucoma that are uncontrolled by previous medical therapy and cases with previous failed surgery. Our aim was to systematically review of the clinical data of currently published ab-interno XEN gel stents with an emphasis on intraocular pressure (IOP), antiglaucoma medication outcomes, and safety profiles.
Methods: We analyzed all of the publications (MEDLINE, EMBASE, Cochrane Library) on the ab-interno XEN gel stent to evaluate the reduction in IOP and antiglaucoma medications following the procedure. The primary outcomes measured for the meta-analysis were reduction in IOP and anti-glaucoma medications. The secondary outcome were adverse events. For each study, we used a random effects analysis model to calculate the mean difference and 95% confidence intervals for the continuous results (reduction in IOP and antiglaucoma medications) using the inverse variance statistical method.
Results: Five hundred twenty-seven articles were checked and 56 studies were found to be relevant with a total of 4,410 eyes. There was a significant reduction in IOP as well as in the number of medications required in patients treated with ab-interno XEN implant either alone or combined with cataract surgery. This new treatment for various types of glaucoma reduced the IOP by 35% to a final average close to 15 mmHg. This reduction was accompanied by a decrease in the number of antiglaucoma medications in all the studies, approximately 2 classes of medication at the price of more needlings. The overall complete success rate was 21.0-70.8% after 2 years using strict criteria originally designed to record success rate in filtration surgery. The incidence of complications vision-threatening was low at <1%.
Conclusions: XEN gel stent was effective and safe for primary and secondary OAG. Further studies should be performed to investigate the impact of ethnicity on the success and failure rate after XEN implantation.

GELS Polyclonal Antibody

ABP58629-003ml Abbkine 0.03ml 189.6 EUR

GELS Polyclonal Antibody

ABP58629-01ml Abbkine 0.1ml 346.8 EUR

GELS Polyclonal Antibody

ABP58629-02ml Abbkine 0.2ml 496.8 EUR

GELS Polyclonal Antibody

E11-202061 EnoGene 100ug/100ul 225 EUR

GELS Polyclonal Antibody

E44H09668 EnoGene 100ul 255 EUR

DIGE gel 3 gels - EACH

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GELS Rabbit Polyclonal Antibody

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Aluminum Hydroxide Gels Adjuvant

E28X0210054 EnoGene 50ml 300 EUR

SCC Buffer for Resolve Gels 1X

20840054-1 Glycomatrix 20 PK(s) 45.41 EUR

SCC Buffer for Resolve Gels 1X

20840054-2 Glycomatrix 40 PK(s) 60.54 EUR

TBS Buffer for Resolve™ Gels 1X

20840056-1 Bio-WORLD 20 PK (s) Ask for price

TBS Buffer for Resolve™ Gels 1X

20840056-2 Bio-WORLD 40 PK (s) Ask for price

GelRED(TM) for Agarose or Page Gels (10000X in water)

S420 GeneOn 0,5 ml 175.2 EUR

GelRED(TM) for Agarose or Page Gels (10000X in water)

S425 GeneOn 5x0,5 ml 699.6 EUR

GelRED(TM) for Agarose or Page Gels (10000X in water)

S425L GeneOn 15x0,5 ml Ask for price

GelRED(TM) for Agarose or Page Gels (10000X in water)

S420-2 GeneOn 2x0,5ml 279 EUR

Tris Glycine Buffer for Resolve Gels 1X

20840053-1 Glycomatrix 20 PK(s) 35.81 EUR

Tris Glycine Buffer for Resolve Gels 1X

20840053-2 Glycomatrix 40 PK(s) 51.77 EUR

Ettan DALT buffer kit 12 precast gels - EACH

17600250 Scientific Laboratory Supplies EACH 336.15 EUR

TBE Buffer with Sodium for Resolve Gels 1X

20840052-1 Glycomatrix 20 PK(s) 69.32 EUR

TBE Buffer with Sodium for Resolve Gels 1X

20840052-2 Glycomatrix 40 PK(s) 128.98 EUR

ENDURO 7.7 Horizontal Electrophoresis 7 x 7cm Gels

LE1001 GenDepot Set 651.6 EUR

ENDURO 7.10 Horizontal Electrophoresis 7 x 10cm Gels

LE1002 GenDepot Set 699.6 EUR

ENDURO 10.10 Horizontal Electrophoresis 10 x 10cm Gels

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ENDURO 15.10 Horizontal Electrophoresis 15 x 10cm Gels

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LE1005 GenDepot Set 1081.2 EUR

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LE1006 GenDepot Set 1170 EUR

Cavitation nucleation and its ductile-to-brittle shape transition in soft gels under translational mechanical impact

  • Cavitation bubbles in the human body, when subjected to impact, are being increasingly considered as a possible brain injury mechanism. However, the onset of cavitation and its complex dynamics in biological materials remain unclear. Our experimental results using soft gels as a tissue simulant show that the critical acceleration (acr) at cavitation nucleation monotonically increases with increasing stiffness of gelatin A/B, while acr for agarose and agar initially increases but is followed by a plateau or even decrease after stiffness reach to ∼100 kPa. Our image analyses of cavitation bubbles and theoretical work reveal that the observed trends in acr are directly linked to how bubbles grow in each gel. Gelatin A/B, regardless of their stiffness, form a localized damaged zone (tens of nanometers) at the gel-bubble interface during bubble growth.
  • In contrary, the damaged zone in agar/agarose becomes significantly larger (> 100 times) with increasing shear modulus, which triggers the transition from formation of a small, damaged zone to activation of crack propagation. STATEMENT OF SIGNIFICANCE: We have studied cavitation nucleation and bubble growth in four different types of soft gels (i.e., tissue simulants) under translational impact. The critical linear acceleration for cavitation nucleation has been measured in the simulants by utilizing a recently developed method that mimics acceleration profiles of typical head blunt events.
  • Each gel type exhibits significantly different trends in the critical acceleration and bubble shape (e.g., A gel-specific sphere-to-saucer transition) with increasing gel stiffness. Our theoretical framework, based on the concepts of a damaged zone and crack propagation in each gel, explains underlying mechanisms of the experimental observations. Our in-depth studies shed light on potential links between traumatic brain injuries and cavitation bubbles induced by translational acceleration, the overlooked mechanism in the literature.

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