scholarly journals Influence of PVA Molecular Weight and Concentration on Electrospinnability of Birch Bark Extract-Loaded Nanofibrous Scaffolds Intended for Enhanced Wound Healing

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4799
Author(s):  
Francis Kamau Mwiiri ◽  
Rolf Daniels
Keyword(s):  
Molecular Weight ◽  
Wound Healing ◽  
Drug Release ◽  
Polymer Solutions ◽  
Ex Vivo ◽  
Polymer Concentration ◽  
Weight Ratio ◽  
Bark Extract ◽  
Birch Bark ◽  
Fiber Morphology

Triterpenes from the outer bark of birch (TE) are known for various pharmacological effects including enhanced wound healing. Apart from an already authorized oleogel, electrospun nanofiber mats containing these triterpenes in a polyvinyl alcohol (PVA) matrix appear to be an advantageous application form. The effects of PVA molecular weight and concentration on the fiber morphology have been investigated. Three different molecular weights of PVA ranging from 67 to 186 kDa were used. The concentration of PVA was varied from 5 to 20 wt%. Polymer solutions were blended with colloidal dispersions of birch bark extract at a weight ratio of 60:40 (wt.%). The estimated viscosity of polymer solutions was directly linked to their concentration and molecular weight. In addition, both pure and blended solutions showed viscoelastic properties with a dominant viscous response in the bulk. Fiber morphology was confirmed using scanning electron microscopy (SEM). Both polymer concentration and molecular weight were found to be significant factors affecting the diameter of the fibers. Fiber diameter increased with a higher molecular weight and polymer concentration as more uniform fibers were obtained using PVA of higher molecular weight (146–186 kDa). In vitro drug release and ex vivo permeation studies indicated a faster drug release of betulin from electrospun scaffolds with lower PVA molecular weight. Our research suggests that the fabricated TE-loaded PVA electrospun dressings represent potential delivery systems of TE for wound care applications.

scholarly journals Electrospun Bioactive Wound Dressing Containing Colloidal Dispersions of Birch Bark Dry Extract

Pharmaceutics ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 770 ◽  
Author(s):  
Francis Kamau Mwiiri ◽  
Johanna M. Brandner ◽  
Rolf Daniels
Keyword(s):  
Wound Healing ◽  
Ex Vivo ◽  
Electrospun Fiber ◽  
Colloidal Dispersions ◽  
Birch Bark ◽  
Fiber Morphology ◽  
Wound Therapy ◽  
Fiber Mats ◽  
Dry Extract

Novel birch bark dry extract (TE)-loaded polyvinyl alcohol (PVA) fiber mats intended for wound therapy were developed through an electrospinning process. Colloidal dispersions containing TE as the active substance were prepared by the high-pressure homogenization (HPH) technique using hydrogenated phospholipids as stabilizer. Subsequently, the colloidal dispersions were blended with aqueous PVA solutions in the ratio of 60:40 (wt.%) and electrospun to form the nanofiber mats. Fiber morphology examined using scanning electron microscopy (SEM) indicated that fibers were uniform and achieved diameters in the size range of 300–1586 nm. Confocal Raman spectral imaging gave good evidence that triterpenes were encapsulated within the electrospun mats. In vitro drug release and ex vivo permeation studies indicated that the electrospun nanofibers showed a sustained release of betulin, the main component of birch bark dry extract, making the examined dressings highly applicable for several wound care applications. Ex vivo wound healing studies proved that electrospun fiber mats containing TE accelerated wound healing significantly more than TE oleogel, which was comparable to an authorized product that consists of TE and sunflower oil and has proved to enhance wound healing. Therefore, our results conclude that the developed TE-PVA-based dressings show promising potential for wound therapy, an area where effective remedy is needed.

scholarly journals Evaporation-induced Rayleigh–Taylor instabilities in polymer solutions

2020 ◽  
Vol 378 (2174) ◽  
pp. 20190533 ◽  
Author(s):  
E. J. Mossige ◽  
V. Chandran Suja ◽  
M. Islamov ◽  
S. F. Wheeler ◽  
Gerald. G. Fuller
Keyword(s):  
Molecular Weight ◽  
Time Scales ◽  
Polymer Solutions ◽  
Critical Concentration ◽  
Polymer Concentration ◽  
Onset Time ◽  
Dense Layer ◽  
Strong Concentration ◽  
Aqueous Polymer ◽  
Gravitational Instabilities

Understanding the mechanics of detrimental convective instabilities in drying polymer solutions is crucial in many applications such as the production of film coatings. It is well known that solvent evaporation in polymer solutions can lead to Rayleigh-Bénard or Marangoni-type instabilities. Here, we reveal another mechanism, namely that evaporation can cause the interface to display Rayleigh–Taylor instabilities due to the build-up of a dense layer at the air–liquid interface. We study experimentally the onset time ( t p ) of the instability as a function of the macroscopic properties of aqueous polymer solutions, which we tune by varying the polymer concentration ( c 0 ), molecular weight and polymer type. In dilute solutions, t p shows two limiting behaviours depending on the polymer diffusivity. For high diffusivity polymers (low molecular weight), the pluming time scales as c 0 − 2 / 3 . This result agrees with previous studies on gravitational instabilities in miscible systems where diffusion stabilizes the system. On the other hand, in low diffusivity polymers the pluming time scales as c 0 − 1 . The stabilizing effect of an effective interfacial tension, similar to those in immiscible systems, explains this strong concentration dependence. Above a critical concentration, c ^ , viscosity delays the growth of the instability, allowing time for diffusion to act as the dominant stabilizing mechanism. This results in t p scaling as ( ν / c 0 ) 2/3 . This article is part of the theme issue ‘Stokes at 200 (Part 1)’.

scholarly journals From a Traditional Medicinal Plant to a Rational Drug: Understanding the Clinically Proven Wound Healing Efficacy of Birch Bark Extract

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e86147 ◽  
Author(s):  
Sandra Ebeling ◽  
Katrin Naumann ◽  
Simone Pollok ◽  
Tina Wardecki ◽  
Sabine Vidal-y-Sy ◽  
...  
Keyword(s):  
Wound Healing ◽  
Medicinal Plant ◽  
Bark Extract ◽  
Birch Bark ◽  
Rational Drug

scholarly journals Solubility and Bioavailability Enhancement of Poorly Aqueous Soluble Atorvastatin:In Vitro,Ex Vivo, andIn VivoStudies

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Madhuri S. Rodde ◽  
Ganesh T. Divase ◽  
Tejas B. Devkar ◽  
Avinash R. Tekade
Keyword(s):  
Drug Release ◽  
Dissolution Rate ◽  
Ex Vivo ◽  
Reductase Activity ◽  
Polymer Concentration ◽  
Water Soluble ◽  
Hmg Coa Reductase ◽  
Coa Reductase

The objective of this investigation was to improve the solubility of the poorly water soluble drug atorvastatin (ATR), using solid dispersion (SD) techniques, with Neem Gum (NG) as a hydrophilic carrier. The effects of the polymer concentration and method of preparation on the solubility and dissolution rate were studied. The results showed that the solubility of ATR increases with increasing NG concentration. However, dissolution rate of ATR from its SD was dependent on the method used to prepare SD. Anin vitrodrug release study revealed that the solvent evaporation technique is a more convenient and effective method of preparing SD than kneading method. The SD was characterized using DSC, SEM, and XRD study. Anin vivostudy was performed in which the 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG CoA) reductase inhibition activity was measured. A significant reduction in HMG CoA reductase activity was observed with SD of ATR compared with the plain drug. Anex vivoabsorption study was carried out using modified apparatus developed in our laboratory. Thein vitrodrug release andin vivoandex vivostudies clearly demonstrated the potential of hydrophilic NG in enhancing the solubility, dissolution rate, and bioavailability of ATR.

Silver sulfadiazine loaded breathable hydrogel sponge for wound healing

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Anamika Pandey ◽  
Munira Momin ◽  
Anita Chando
Keyword(s):  
Wound Healing ◽  
Drug Release ◽  
Ex Vivo ◽  
Release Kinetics ◽  
Antimicrobial Property ◽  
Morphological Characteristics ◽  
Silver Sulfadiazine ◽  
Scanning Calorimetry ◽  
Casting Technique

AbstractObjectivesPatients with serious injury need special care and treatment to control the infection, as wound sepsis is one of the major causes of death. Silver sulfadiazine (SSD) is widely used as an antimicrobial agent which promotes healing and re-epithelialization. However, due to certain drawbacks such as inflammation and cytotoxicity, the need for novel drug delivery modality emerges. The objective of this study was to develop natural polymeric (chitosan and gelatin) hydrogel sponges containing SSD and evaluate its efficacy in wound healing using animal models.MethodsSSD containing hydrogel sponges were prepared by solvent casting technique. Scanning electron microscopy (SEM) and Differential scanning calorimetry (DSC) were used to evaluate morphological characteristics of the hydrogel sponges. Anti-thrombogenic property, drug release studies, drug release kinetics, antimicrobial property, and wound healing effect were also studied in detail.ResultsThe optimized batch of hydrogel sponges (CG4) consists of 1% SSD wt., 10% wt. Gelatin, 1% wt. Chitosan and honey 7.5% wt. as plasticizer. At the 12th hour, in vitro and ex vivo drug release was found to be 76.994±0.67% and 24.22±0.57% respectively. CG4 batch had enhanced in vitro antimicrobial activity as compared to conventional marketed cream. The developed SSD hydrogel sponges showed a faster rate of wound healing as compared to a marketed cream. Animals treated with CG4 formulation showed complete angiogenesis and re-epithelialization by 8th day, whereas 12 days were required for complete wound healing with marketed cream.ConclusionsThe prepared hydrogel sponges can serve as a potential alternative for wound healing dressing as compared to the marketed product.

scholarly journals Chitosan-Coated Nanoparticles: Effect of Chitosan Molecular Weight on Nasal Transmucosal Delivery

2019 ◽  
Author(s):  
Franciele Aline Bruinsmann ◽  
Stefania Pigana ◽  
Tanira Aguirre ◽  
Gabriele Dadalt Souto ◽  
Gabriele Garrastazu Pereira ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Drug Release ◽  
Surface Charge ◽  
Nasal Mucosa ◽  
Encapsulation Efficiency ◽  
Ex Vivo ◽  
Droplet Size Distribution ◽  
Particle Number Density ◽  
One Pot

Drug delivery to the brain represents a challenge especially in the therapy of central nervous system malignancies. Simvastatin (SVT), as other statins, has shown potential anticancer properties that are difficult to exploit in the CNS. In the present work the physico-chemical, mucoadhesive and permeability enhancing properties of simvastatin-loaded poly-ε-caprolactone nanocapsules coated with chitosan for nose-to-brain administration were investigated. Lipid-core nanocapsules coated with different molecular weight (MW) chitosans (LNCchit) prepared by a novel one-pot technique were characterized for particle size, surface charge, particle number density, morphology, drug encapsulation efficiency, interaction between surface nanocapsules with mucin, drug release and permeability across two nasal mucosa models. Results show that all formulations present adequate particle size (below 220 nm), positive surface charge, narrow droplet size distribution (PDI<0.2) and high encapsulation efficiency. Nanocapsules presented controlled drug release and mucoadhesive properties dependent on the MW of the coating chitosan. The results of permeation across RPMI 2650 human nasal cell line evidenced that LNCchit increased the permeation of SVT. In particular, the amount of SVT permeated after 4h for nanocapsules coated with low MW chitosan, high MW chitosan and control SVT was 13.91 ± 0.78 µg, 9.15 ± 1.23 µg and 1.42 ± 0.21 µg respectively. These results were confirmed by the SVT ex vivo permeation across rabbit nasal mucosa. This study highlighted the suitability of LNCchit as promising strategy for the administration of simvastatin for a nose-to-brain approach for the therapy of brain tumors.

scholarly journals Chitosan-Coated Nanoparticles: Effect of Chitosan Molecular Weight on Nasal Transmucosal Delivery

Pharmaceutics ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 86 ◽  
Author(s):  
Franciele Bruinsmann ◽  
Stefania Pigana ◽  
Tanira Aguirre ◽  
Gabriele Souto ◽  
Gabriela Pereira ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Central Nervous System ◽  
Nervous System ◽  
Drug Release ◽  
Surface Charge ◽  
Nasal Mucosa ◽  
Encapsulation Efficiency ◽  
Ex Vivo ◽  
Droplet Size Distribution ◽  
One Pot

Drug delivery to the brain represents a challenge, especially in the therapy of central nervous system malignancies. Simvastatin (SVT), as with other statins, has shown potential anticancer properties that are difficult to exploit in the central nervous system (CNS). In the present work the physico–chemical, mucoadhesive, and permeability-enhancing properties of simvastatin-loaded poly-ε-caprolactone nanocapsules coated with chitosan for nose-to-brain administration were investigated. Lipid-core nanocapsules coated with chitosan (LNCchit) of different molecular weight (MW) were prepared by a novel one-pot technique, and characterized for particle size, surface charge, particle number density, morphology, drug encapsulation efficiency, interaction between surface nanocapsules with mucin, drug release, and permeability across two nasal mucosa models. Results show that all formulations presented adequate particle sizes (below 220 nm), positive surface charge, narrow droplet size distribution (PDI < 0.2), and high encapsulation efficiency. Nanocapsules presented controlled drug release and mucoadhesive properties that are dependent on the MW of the coating chitosan. The results of permeation across the RPMI 2650 human nasal cell line evidenced that LNCchit increased the permeation of SVT. In particular, the amount of SVT that permeated after 4 hr for nanocapsules coated with low-MW chitosan, high-MW chitosan, and control SVT was 13.9 ± 0.8 μg, 9.2 ± 1.2 µg, and 1.4 ± 0.2 µg, respectively. These results were confirmed by SVT ex vivo permeation across rabbit nasal mucosa. This study highlighted the suitability of LNCchit as a promising strategy for the administration of simvastatin for a nose-to-brain approach for the therapy of brain tumors.

Fabrication of cefixime nanoparticles loaded films and their ex vivo antimicrobial effect on periodontitis patient’s saliva

2021 ◽  
Vol 10 ◽  
Author(s):  
Rakeshkumar Parmar ◽  
Mohammad Salman M ◽  
Payal Chauhan
Keyword(s):  
Molecular Weight ◽  
Drug Release ◽  
Ex Vivo ◽  
Chitosan Film ◽  
Inhibition Zone ◽  
Release Profile ◽  
Low Molecular Weight ◽  
Drug Release Profile ◽  
Low Molecular Weight Chitosan

Aim: This study was designed to prepare and evaluate cefixime-loaded nanoparticles containing low molecular weight chitosan films for the enhanced topical treatment of periodontitis. Methods: To fabricate the enhanced antimicrobial films, a nanoprecipitation method for cefixime nanoparticles followed by a solvent evaporation method for these nanoparticles loaded films were adopted in this study. Nine batches of nanoparticles (NPs) with different concentrations of ethyl cellulose and polyvinyl alcohol were prepared and evaluated. Furthermore, nine batches of optimized NPs loaded films with different concentrations of low molecular weight chitosan and glycerol were fabricated and evaluated. Optimized NPs loaded films were assessed for their antimicrobial activity against the periodontitis patient’s saliva samples. Results: The FT-IR spectroscopy and XRD study revealed that there was no interaction between the drug and all other excipients and the drug remained amorphous form in chitosan film. The SEM study revealed that the prepared NPs were spherical in shape and uniformly distributed in chitosan film. In vitro drug release study revealed the NPs have a sustained release profile up to 8 days and NPs loaded films have up to 11 days. The conventional marketed mouth wash shows a low inhibition zone of 5.70 ± 0.043 mm, whereas NPs loaded film shows a higher inhibition zone of 6.72 ± 0.063 mm against periodontal microorganisms present in the patient’s saliva. The stability study revealed that the optimized NPs loaded film shows no dramatic change in drug release profile and folding endurance after six months. Conclusion: This present study highlights the possible usage of cefixime NPs loaded films in enhanced periodontal treatment.

Sign in / Sign up

Export Citation Format

Share Document