Antibacterial Activity Of Scaffolds Research Articles

Fabrication and evaluation of poly (vinyl alcohol)/gelatin fibrous scaffold containing ZnO nanoparticles for skin tissue engineering applications

Skin engineering offers innovative constructs for the treatment of a wide range of skin diseases. Hybrid scaffolds were fabricated using poly (vinyl alcohol), gelatin and ZnO nanoparticles by electrospinning. Different concentrations of ZnO nanoparticles (0%, 0.5% and 1%) were incorporated into the PVA/gelatin scaffolds and the constructs were characterized by SEM, FTIR, XRD, contact angle, swelling, degradation, and biomechanical tests; the release behavior of nanoparticles from the scaffolds was also evaluated. In cellular studies, human mesenchymal stem cells (hu-MSCs) were extracted from the umbilical cord of a newborn baby and characterized by flow cytometry. Cell-seeded scaffolds were assessed by in vitro biocompatibility, SEM images and live/dead assay. Finally, the antibacterial activity of scaffolds against E. coli and S. aureus strain was determined. Due to the presence of the hydrophilic biopolymer of gelatin in the contact angle test, the scaffolds showed hydrophilic properties. With the addition of nanoparticles, the hydrophilicity, water absorption and degradation rates of scaffolds were somewhat reduced. No difference in tensile modulus was observed between scaffolds. The release rate of nanoparticles from scaffolds increased over time. The immunoprofile evaluation of extracted cells by flow cytometry technique confirmed the mesenchymal nature of the cells. Fluorescent staining showed that most cells were alive and had appropriate shape during six days of cell culture on PVA/gelatin/ZnO1wt% scaffold. All scaffolds had acceptable biocompatibility, but control and PVA/gelatin groups showed a higher cell survival rate. Scaffolds containing nanoparticles had a direct effect on inhibiting bacterial growth in a dose-dependent manner. Our findings suggest that composite scaffolds containing ZnO nanoparticles seeded with hu-MSCs might be suitable for promoting skin healing.

Fabrication and characterization of an antibacterial chitosan/silk fibroin electrospun nanofiber loaded with a cationic peptide for wound-dressing application

Wound infections are still problematic in many cases and demand new alternatives for current treatment strategies. In recent years, biomaterials-based wound dressings have received much attention due to their potentials and many studies have been performed based on them. Accordingly, in this study, we fabricated and optimized an antibacterial chitosan/silk fibroin (CS/SF) electrospun nanofiber bilayer containing different concentrations of a cationic antimicrobial peptide (AMP) for wound dressing applications. The fabricated CS/SF nanofiber was fully characterized and compared to the electrospun silk fibroin and electrospun chitosan alone in vitro. Then, the release rate of different concentrations of peptide (16, 32, and 64 µg/ml) from peptide-loaded CS/SF nanofiber was investigated. Finally, based on cytotoxic activity, the antibacterial activity of scaffolds containing 16 and 32 µg/ml of the peptide was evaluated against standard and multi-drug resistant strains of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa isolated from burn patients. The peptide-loaded CS/SF nanofiber displayed appropriate mechanical properties, high water uptake, suitable biodegradation rate, a controlled release without cytotoxicity on Hu02 human foreskin fibroblast cells at the 16 and 32 µg/ml concentrations of peptide. The optimized CS/SF containing 32 μg/ml peptide showed strong antibacterial activity against all experimental strains from standard to resistance. The results showed that the fabricated antimicrobial nanofiber has the potential to be applied as a wound dressing for infected wound healing, although further studies are needed in vivo.

Biological and structural properties of graphene oxide/curcumin nanocomposite incorporated chitosan as a scaffold for wound healing application

AimsThe purpose of this research is to fabricate chitosan (CS)/graphene oxide (GO)/curcumin (Cur) 3D scaffolds through the freeze-drying method for wound dressing applications. Main methodsGO is produced by Hammer's method; then, it is characterized by X-ray diffraction and TEM analysis. Fabricated scaffolds are characterized by FTIR, FESEM, AFM, water vapor transmission rate, PBS absorption, contact angle, tensile strength, porosity measurement, biodegradability, and drug release methods. The cell viability and morphology of NIH/3 T3 cells are investigated by WST assay kit and FESEM analysis, and the antibacterial activity of scaffolds is determined by the optical density (OD) method. The photothermal antibacterial activity is characterized by NIR irradiation, too. Key findingsThe mean pore diameter of scaffolds adjusted by the incorporation of about 0–1.5%wt. of GO/Cur nanocomposite into CS matrix, decreasing from 87 to 40 μm that can be attributed to the intermolecular bonds between CS and GO/Cur nanocomposite. Besides, the PBS absorption of scaffolds enhances by the addition of GO/Cur, especially 1% of it. Furthermore, the overall average of cell viability of nanocomposite scaffolds is about 95%, and the FESEM images show that NIH/3T3 fibroblasts well spread on the nanocomposite scaffolds. GO/Cur has a significant influence on the antibacterial activity of CS scaffolds as CS/GO/Cur 0.5 scaffold diminishes the bacterial growth to about 52% of the control sample's growth. SignificanceThe results evidence the antibacterial CS/GO/Cur scaffolds are excellent supports for cell growth and proliferation, and they could be promising candidates for wound dressing applications.

Evaluation of the Antibacterial Activity and Cell Response for 3D-Printed Polycaprolactone/Nanohydroxyapatite Scaffold with Zinc Oxide Coating.

Among 3D-printed composite scaffolds for bone tissue engineering, researchers have been attracted to the use of zinc ions to improve the scaffold’s anti-bacterial activity and prevent surgical site infection. In this study, we assumed that the concentration of zinc ions released from the scaffold will be correlated with the thickness of the zinc oxide coating on 3D-printed scaffolds. We investigated the adequate thickness of zinc oxide coating by comparing different scaffolds’ characteristics, antibacterial activity, and in vitro cell response. The scaffolds’ compressive modulus decreased as the zinc oxide coating thickness increased (10, 100 and 200 nm). However, the compressive modulus of scaffolds in this study were superior to those of other reported scaffolds because our scaffolds had a kagome structure and were made of composite material. In regard to the antibacterial activity and in vitro cell response, the in vitro cell proliferation on scaffolds with a zinc oxide coating was higher than that of the control scaffold. Moreover, the antibacterial activity of scaffolds with 100 or 200 nm-thick zinc oxide coating on Escherichia coli was superior to that of other scaffolds. Therefore, we concluded that the scaffold with a 100 nm-thick zinc oxide coating was the most appropriate scaffold to use as a bone-regenerating scaffold, given its mechanical property, its antibacterial activity, and its in vitro cell proliferation.

Preparation and Evaluation of Composite Nanofibers Containing Vancomycin

Background: Electrospinning of chitosan/poly ethylene oxide (CS/PEO) and poly caprolactone (PCL)/ CS/ PEO/ solutions with the addition of vancomycin to create nanofibers with antibacterial properties were examined. Methods: Polymeric nanofibers including CS/PEO and PCL /CS/PEO/ vancomycin were produced by electrospinning method. The morphology of electrospun nanofibers was studied with use of scanning electron microscopy (SEM). Moreover, the chemical structures of the nanofibers were evaluated by FT-IR. The drug release of nanofibers was also investigated by UV-Vis spectrophotometry. The antibacterial activity of scaffolds was tested by two type bacteria including Streptococcus pyogenes and Staphylococcus aureus. Results: The SEM images indicated that the addition of vancomycin as much as 0/8wt brings about the best nanofiber. Also, the morphology of electrospun nanofiber is dependent on the viscosity of the solution and the ratio of PCL/CS /PEO/vancomycin. According to the results of vancomycin releasing from nanofibers, the best results were obtained in the presence of PCL/ CS/PEO/0/8wt vancomycin nanofibers as healing sample. Conclusion: The result of antibacterial activity of nanofiber and drug releasing showed this nanofiber can used as an antibacterial coating to prevent the spread of infections in the wound surface.

A protein/antibiotic releasing poly(lactic-co-glycolic acid)/lecithin scaffold for bone repair applications

Novel poly(lactic-co-glycolic acid) (PLGA)-hybridizing-lecithin scaffolds loaded with drug or protein were prepared with water/oil/water techniques and sintering microspheres technique. In such fabricated composite scaffolds (abbreviated “PLGA/Lec-SMS”), the introduction of lecithin component has been proven capable of largely enhancing Gentamicin (GS) and protein (Bovine Serum Albumin) encapsulation efficiency. The in vitro GS and BSA releasing profiles of PLGA/Lec-SMS system were plotted basing over 60 days’ and 18 days’ data collection, respectively. It indicates a sustained releasing tendency despite a burst at the very beginning. The antibacterial properties of GS-laden scaffolds were determined in vitro, and the antibacterial activity of scaffolds was enhanced by incorporating lecithin into PLGA bulks. Additionally, mesenchymal stem cells (MSCs) were seeded onto PLGA-SMS and PLGA/Lec-SMS in vitro. The outcome confirmed PLGA/Lec(5%)-SMS functions to improve MSC proliferation and also to enhance general ALP production and calcium secretion which is the vital markers for osteogenesis. In conclusion, this newly designed antibiotic releasing PLGA/Lec-SMS is promising for bone-repairing therapeutics.