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1.
Int J Pharm ; 588: 119782, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-32822780

ABSTRACT

Progesterone-loaded poly(lactic) acid fibrous polymeric patches were produced using electrospinning and pressurized gyration for intra-vaginal application to prevent preterm birth. The patches were intravaginally inserted into rats in the final week of their pregnancy, equivalent to the third trimester of human pregnancy. Maintenance tocolysis with progesterone-loaded patches was elucidated by recording the contractile response of uterine smooth muscle to noradrenaline in pregnant rats. Both progesterone-loaded patches indicated similar results from release and thermal studies, however, patches obtained by electrospinning had smaller average diameters and more uniform dispersion compared to pressurized gyration. Patches obtained by pressurized gyration had better results in production yield and tensile strength than electrospinning; thereby pressurized gyration is better suited for scaled-up production. The patches did not affect cell attachment, viability, and proliferation on Vero cells negatively. Consequently, progesterone-loaded patches are a novel and successful treatment strategy for preventing preterm birth.


Subject(s)
Premature Birth , Progesterone , Administration, Intravaginal , Animals , Chlorocebus aethiops , Female , Humans , Infant, Newborn , Pregnancy , Premature Birth/prevention & control , Progestins , Rats , Vero Cells
2.
J Nanosci Nanotechnol ; 20(10): 6354-6367, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32384985

ABSTRACT

Metallic structures are conventionally fabricated with high temperature/deformation processes resulting the smallest possible microscopic structures in the order of several hundreds of micrometer. Therefore, to obtain structures with fibers smaller than 100 µm, those are unsuitable. In this study, electrospinning, a fiber fabrication technique commonly used for polymers, was adopted to fabricate a WE43 magnesium alloy-like fibrous structure. The aim is to adopt metallic WE43 alloy to regenerative medicine using tissue engineering approach by mimicking its composition inside of a fibrous structure. The solution required for electrospinning was obtained with water soluble nitrates of elements in WE43 alloy, and PVP or PVA were added to obtain a spinnable viscosity which was pyrolised away during heat treatment. Electrospinning parameters were optimized with naked-eye observations and SEM as 1.5 g salts and 5 wt.% PVA containing solution prepared at 90 °C and electrospun under 30 kV from a distance of 12-15 cm with a feeding rate of 5 µl/min. Then the samples were subjected to a multi-step heat treatment under argon to remove the polymer and calcinate the nitrates into oxides which was designed based on thermal analyses and reaction kinetics calculations as 6 h at 230 °C, 8.5 h at 390 °C, 5 h at 465 °C, 80 h at 500 °C and 10 h at 505 °C, consecutively. The characterizations conducted in terms of structure, composition and crystallinity with XRD, XPS, EDX and SEM showed that it is possible to obtain MgaYbNdcZrdOx (empirical) fibers with the same composition as WE43 in sub-millimeter sizes using this approach.

3.
J Mater Sci Mater Med ; 31(2): 16, 2020 Jan 21.
Article in English | MEDLINE | ID: mdl-31965360

ABSTRACT

Powders of ß-tricalcium phosphate [ß-TCP, ß-Ca3(PO4)2] and composite powders of ß-TCP and polyvinyl alcohol (PVA) were synthesized by using wet precipitation methods. First, the conditions for the preparation of single phase ß-TCP have been delineated. In the co-precipitation procedure, calcium nitrate and diammonium hydrogen phosphate were used as calcium and phosphorous precursors, respectively. The pH of the system was varied in the range 7-11 by adding designed amounts of ammonia solution. The filtered cakes were desiccated at 80 °C and subsequently calcined at different temperatures in the range between 700-1100 °C. Later on, rifampicin form II was used to produce drug-loaded ß-TCP and PVA/ß-TCP powders. All the synthesized materials have been characterized from morphological (by scanning electron microscopy) and structural-chemical (by X-ray diffraction and Fourier transform infrared spectroscopy) point of view. The drug loading capacity of the selected pure ß-TCP powder has been assessed. The biological performance (cytocompatibility in fibroblast cell culture and antibacterial efficacy against Escherichia coli and Staphylococcus aureus) has been tested with promising results. Application perspectives of the designed drug-bioceramic-polymer blends are advanced and discussed.


Subject(s)
Calcium Phosphates/chemistry , Osteocytes/physiology , Animals , Anti-Bacterial Agents , Bone Substitutes , Cell Proliferation , Cell Survival , Drug Liberation , Hydrogen-Ion Concentration , Materials Testing , Osteogenesis , Polyvinyl Alcohol , Rifampin , Tissue Engineering , Tissue Scaffolds
4.
IEEE Trans Nanobioscience ; 17(3): 321-328, 2018 07.
Article in English | MEDLINE | ID: mdl-29994218

ABSTRACT

Biocompatible nanocomposite electrospun fibers containing Polyurethane/Chitosan/ $\beta $ -Tri calcium phosphate with diverse concentrations were designed and produced through the electrospinning process for bone tissue engineering applications. After the production process, density measurement, viscosity, electrical conductivity, and tensile strength measurement tests were carried out as physical analyses of blended solutions. The chemical structural characterization was scrutinized using Fourier transform infrared spectrometer (FTIR), and scanning electron microscopy (SEM) was used to observe the morphological details of developed electrospun scaffolds. Cell viability, attachment, and proliferation were performed using a L929 fibroblast cell line. Based on the physical, SEM, FTIR analysis, and cell culture studies, preferable nanofiber composition was selected for further studies. Amoxicillin (AMX) was loaded to that selected nanofiber composition for examination of the drug release. In comparison with other studies on similar AMX controlled products, higher drug loading and encapsulation efficiencies were obtained. It has been clearly found that the developed nanofiber composites have potential for bone tissue engineering applications.


Subject(s)
Amoxicillin/chemistry , Bone and Bones , Polyurethanes/chemistry , Tissue Engineering/methods , Tissue Scaffolds/chemistry , Animals , Bone and Bones/cytology , Bone and Bones/physiology , Calcium Phosphates/chemistry , Cell Line , Chitosan/chemistry , Electrochemical Techniques/methods , Mice
5.
J Nanosci Nanotechnol ; 18(4): 2415-2421, 2018 Apr 01.
Article in English | MEDLINE | ID: mdl-29442910

ABSTRACT

In this study, antibacterial performance of the coaxially electrospun Poly-ε-caprolactone (PCL)-chitosan core-shell scaffolds developed, optimized and identified physically and chemically in our previous study, were evaluated for the suitability in wound healing applications. The aim of utilizing a core-shell fibrous scaffold with PCL as core and chitosan as shell was to combine natural biocompatibility, biodegradability and antibacterial properties of chitosan with mechanical properties and resistance to enzymatic degradation of PCL. The scaffolds were prepared with the optimized parameters, obtained from our previous study. Thickness and contact angle measurements as well as Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analyses confirmed repeated fabrication of PCL-chitosan core-shell scaffolds. In this study, assays specific to wound dressing materials, such as water vapor transmission rate (WVTR), in vitro degradability and antibacterial tests were carried out. WVTR value of PCL-chitosan core-shell scaffolds was higher (2315 ± 3.4 g/m2 · day) compared to single PCL scaffolds (1654 ± 3.2 g/m2 · day) due to the higher inter-fiber pore size. Additionally, in vitro degradability assays showed that the susceptibility of chitosan to enzymatic degradation can be significantly improved by hybridization with more resistant PCL while still keeping the scaffold to be considered as biodegradable. Finally, inhibition ratio and inhibition zone measurements showed that the PCL-chitosan core-shell polymeric scaffolds had significant antibacterial performance (52.860 ± 2.298% and 49.333 ± 0.719% inhibition ratios; 13.975 ± 0.124 mm and 12.117 ± 0.133 mm clear inhibition zones, against E. coli and S. aureus, respectively), close to the native chitosan. Therefore, the developed scaffolds can be considered as suitable candidates for biodegradable wound dressing applications.


Subject(s)
Anti-Bacterial Agents/pharmacology , Caproates/pharmacology , Chitosan/pharmacology , Escherichia coli/drug effects , Lactones/pharmacology , Tissue Scaffolds , Cell Proliferation , Polyesters , Staphylococcus aureus , Tissue Engineering
6.
J Biomater Appl ; 32(9): 1300-1313, 2018 04.
Article in English | MEDLINE | ID: mdl-29388455

ABSTRACT

In this study, dry air plasma jet and dielectric barrier discharge Ar + O2 or Ar + N2 plasma modifications and their effects on wettability, topography, functionality and biological efficiency of the hybrid polymeric poly (ε-caprolactone)/chitosan scaffolds were reported. The samples treated with Ar + O2 dielectric barrier discharge plasma (80 sccm O2 flow rate, 3-min treatment) or with dry air plasma jet (15-cm nozzle-sample distance, 13-min treatment) had the closest wettability (49.11 ± 1.83 and 53.60 ± 0.95, respectively) to the commercial tissue culture polystyrene used for cell cultivation. Scanning electron microscopy images and X-ray photoelectron spectrometry analysis showed increase in topographical roughness and OH/NH2 functionality, respectively. Increased fluid uptake capacity for the scaffolds treated with Ar + O2 dielectric barrier discharge plasma (73.60% ± 1.78) and dry air plasma jet (72.48% ± 0.75) were also noted. Finally, initial cell attachment as well as seven-day cell viability, growth and proliferation performances were found to be significantly better for both plasma treated scaffolds than for untreated scaffolds.


Subject(s)
Chitosan/chemistry , Plasma Gases/chemistry , Polyesters/chemistry , Tissue Scaffolds/chemistry , Biocompatible Materials/chemistry , Cell Adhesion , Cell Line , Cell Survival , Fibroblasts/cytology , Humans , Materials Testing , Surface Properties
7.
J Biosci Bioeng ; 122(2): 232-9, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26906227

ABSTRACT

In the study presented here, in order to improve the surface functionality and topography of poly (ε-caprolactone) (PCL)/chitosan/PCL hybrid tissue scaffolds fabricated layer by layer with electrospinning technique, an atmospheric pressure nozzle type plasma surface modification was utilized. The optimization of the plasma process parameters was carried out by monitoring the changes in surface hydrophilicity by using contact angle measurements. SEM, AFM and XPS analyses were utilized to observe the changes in topographical and chemical properties of the modified surfaces. The results showed that applied plasma modification altered the nanotopography and the functionality of the surfaces of the scaffolds. The modification applied for 9 min from a distance of 17 cm was found to provide the possible contact angle value (75.163±0.083) closest to the target value which is the value of tissue culture polystyrene (TCPS) petri dishes (∼49.7°), compared to the unmodified samples (84.46±3.86). In vitro cell culture was carried out by L929 mouse fibroblast cell line in order to examine the effects of plasma surface modification on cell-material interactions. Standard MTT assay showed improved cell viability on/within modified scaffolds confirmed with the observations of the cell attachment and the morphology by means of SEM, fluorescence and confocal imaging. The experiments performed in the study proved the enhanced biocompatibility of the nozzle type dry air plasma modified scaffolds.


Subject(s)
Air , Caproates/chemistry , Cell Culture Techniques/methods , Chitosan/chemistry , Fibroblasts/cytology , Lactones/chemistry , Surface Properties , Tissue Scaffolds/chemistry , Animals , Atmospheric Pressure , Cell Line , Cell Survival/drug effects , Hydrophobic and Hydrophilic Interactions , Mice , Nanostructures/chemistry , Nanostructures/ultrastructure , Polystyrenes/chemistry , Tissue Engineering/methods
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