In vitro and in vivo evaluation of chitosan-alginate/gentamicin wound dressing nanofibrous with high antibacterial performance

Wound dressings based on nanofiber polymer scaffolds with good antimicrobial performance and skin reconstruction ability are promising options to thwart wound infection and accelerate wound healing. This paper reports on the synthesis via electrospinning of chitosan-alginate (CS-Alg) nanofiber dressings with various amounts of gentamicin (Gn; 0–10 wt%) as a drug delivery system. Smooth and continuous nanofibers with no obvious beads were created, with increases in the amount of Gn resulting in reduced fiber diameter. Antimicrobial tests showed the Gn-loaded nanofibers had good antibacterial performance as indicated by the inhibition of bacterial growth. CS-Alg nanofibers loaded with higher Gn concentrations exhibited greater antibacterial performance than those with lower Gn concentrations. In vitro cell culture studies demonstrated that CS-Alg wound dressings with 1–3% Gn improved L929 cell attachment and proliferation more than wound dressings with higher Gn concentrations. In vivo experiments revealed that Cs-Alg nanofibers loaded with 3% Gn significantly enhanced skin regeneration in a Balb/C mice model by stimulating the formation of a thicker dermis, increasing collagen deposition, and increasing the formation of new blood vessels and hair follicles. Collectively, Gn-loaded CS-Alg wound dressings can be considered a good candidate for drug delivery systems and skin regeneration applications. © 2019 Elsevier Lt

Drug release, cytocompatibility, bioactivity, and antibacterial activity of doxycycline loaded Mg-Ca-TiO2 composite scaffold

Mg-Ca-TiO2 (MCT) composite scaffolds loaded with different concentrations of doxycycline (DC) with a network of interconnected pores with good compressive strength (5 ± 0.1 MPa) were fabricated via space holder method for the first time. The results showed that MCT-DC scaffolds possess a porosity and pore size in the range of 65–67% and 600–800 μm respectively. The bioactivity results exhibited the apatite formation on the MCT-DC scaffold surface, indicating that DC did not obstruct the bioactivity of MCT. The MCT-DC scaffolds drug release profiles show the initial burst and sustained drug release (55–75%) and the release rate could be adjusted via altering the DC concentration. The MCT loaded with 1 and 5% DC did not indicate cytotoxic behavior against MG63 cells while further DC loading resulted in some toxicity. Antimicrobial properties of MCT-DC scaffolds against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria were examined and the results reveal oblivious inhibition zone around each MCT-DC scaffold whereas no obvious inhibition is observed around the MCT scaffold. Therefore, MCT-DC composite scaffolds with low concentration of DC could be alternative candidates for infection prevention and bone tissue engineering

In vitro and in vivo evaluation of chitosan-alginate/gentamicin wound dressing nanofibrous with high antibacterial performance

Wound dressings based on nanofiber polymer scaffolds with good antimicrobial performance and skin reconstruction ability are promising options to thwart wound infection and accelerate wound healing. This paper reports on the synthesis via electrospinning of chitosan-alginate (CS-Alg) nanofiber dressings with various amounts of gentamicin (Gn; 0–10 wt%) as a drug delivery system. Smooth and continuous nanofibers with no obvious beads were created, with increases in the amount of Gn resulting in reduced fiber diameter. Antimicrobial tests showed the Gn-loaded nanofibers had good antibacterial performance as indicated by the inhibition of bacterial growth. CS-Alg nanofibers loaded with higher Gn concentrations exhibited greater antibacterial performance than those with lower Gn concentrations. In vitro cell culture studies demonstrated that CS-Alg wound dressings with 1–3% Gn improved L929 cell attachment and proliferation more than wound dressings with higher Gn concentrations. In vivo experiments revealed that Cs-Alg nanofibers loaded with 3% Gn significantly enhanced skin regeneration in a Balb/C mice model by stimulating the formation of a thicker dermis, increasing collagen deposition, and increasing the formation of new blood vessels and hair follicles. Collectively, Gn-loaded CS-Alg wound dressings can be considered a good candidate for drug delivery systems and skin regeneration applications

Drug release, cytocompatibility, bioactivity, and antibacterial activity of doxycycline loaded Mg-Ca-TiO2 composite scaffold

© 2017 Mg-Ca-TiO2 (MCT) composite scaffolds loaded with different concentrations of doxycycline (DC) with a network of interconnected pores with good compressive strength (5 ± 0.1 MPa) were fabricated via space holder method for the first time. The results showed that MCT-DC scaffolds possess a porosity and pore size in the range of 65–67% and 600–800 μm respectively. The bioactivity results exhibited the apatite formation on the MCT-DC scaffold surface, indicating that DC did not obstruct the bioactivity of MCT. The MCT-DC scaffolds drug release profiles show the initial burst and sustained drug release (55–75%) and the release rate could be adjusted via altering the DC concentration. The MCT loaded with 1 and 5% DC did not indicate cytotoxic behavior against MG63 cells while further DC loading resulted in some toxicity. Antimicrobial properties of MCT-DC scaffolds against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria were examined and the results reveal oblivious inhibition zone around each MCT-DC scaffold whereas no obvious inhibition is observed around the MCT scaffold. Therefore, MCT-DC composite scaffolds with low concentration of DC could be alternative candidates for infection prevention and bone tissue engineering

Drug delivery and cytocompatibility of ciprofloxacin loaded gelatin nanofibers-coated Mg alloy

In this study, gelatin-ciprofloxacin (Gel-Cip) nanofibers containing various amounts of Cip (0, 2, 4 and, 8 wt%) were fabricated on the surface of Mg-1Ca alloy via an electrospinning process. Microscopic characterization indicated a porous network structure with fiber diameters in the range of 150–170 nm. Prolonged drug release was attained from Gel-Cip nanofibers coating along with initial rapid drug release of around 20–22% during 12 h, followed by a slow release stage that can effectively control the infection. The incorporation of 2–4 wt% Cip into Gel nanofibers coating significantly increased the antibacterial performance and corrosion resistance of the uncoated Mg-Ca alloy without showing an inhibitory influence on the cytocompatibility characteristic. Hence, it is potentially appropriate as the novel electrospun nanofibers coating material for bone regeneration application

Fabrication and characterisation of novel ZnO/MWCNT duplex coating deposited on Mg alloy by PVD coupled with dip-coating techniques

Zinc oxide (ZnO)/multi-walled carbon nanotube (MWCNT) duplex coating was synthesized on Mg-0.8Ca-3Zn alloy by physical vapour deposition (PVD) combined with dip coating. The ZnO inner layer was 1.1 μm thick and consisted of spherical nanoparticles. The outer layer of the MWCNTs was 10.2 μm thick, the diameter of the raw MWCNTs was approximately 42 nm, and their lengths were around a few microns. The ZnO/MWCNT duplex coating showed higher compressive strength than the single-layer coated ZnO and bare Mg alloy after immersion in simulated body fluid (SBF) solution. Polarisation and electrochemical impedance spectroscopy tests revealed that the ZnO/MWCNT duplex coating has lower corrosion current (icorr = 7.2 μA/cm2) and higher charge transfer resistance (Rt = 5250 Ω cm2) than the ZnO single-layer coated (Rt = 3420 Ω cm2; icorr = 42.3 μA/cm2) and bare Mg alloy (Rt = 1720 Ω cm2; icorr = 205.4 μA/cm2). In the immersion test, the ZnO/MWCNT duplex coating protected the substrate effectively in the SBF solution, while moderate to serious damage in this electrolyte was observed on the surface of the ZnO-coated and bare samples, respectively. The results indicated that the deposition of MWCNTs as the outer layer and ZnO as the inner layer on the surface of bare Mg alloy sample is a promising technique to enhance its corrosion resistance

Antibacterial activity and in vivo wound healing evaluation of polycaprolactone-gelatin methacryloyl-cephalexin electrospun nanofibrous

Infections, particularly those induced via drug resistant pathogens, can cause serious issues in wound healing process. In this study, cephalexin (CEX), as an effective antibiotic, was loaded into polycaprolactone (PCL)-gelatin methacryloyl (GelMA) nanofibrous by electrospinning for the development of a new wound dressing. The electrospun nanofibrous possessed continuous and smooth structure with the fiber diameters ranging from 280 to 330 nm. Swelling examination exhibited that the electrospun nanofibrous could take up water by 400–600%. Antibacterial activity of PCL/GelMA loading with CEX had a great inhibition towards both Gram-positive Staphylococcus aureus and negative-bacteria Escherichia coli. The hematoxylin-eosin (H&E) and Masson's trichrome (MT) staining results from treated wounds with PCL/GelMA-CEX nanofibrous exhibited improved re-epithelialization and collagen deposition. Taken together, our study illustrate the PCL/GelMA-CEX nanofibrous can be promising for use as an effective antibacterial wound dressing in skin regeneration

Coating biodegradable magnesium alloys with electrospun poly-L-lactic acid-åkermanite-doxycycline nanofibers for enhanced biocompatibility, antibacterial activity, and corrosion resistance

Magnesium alloys are attracting increasing attention for orthopedic applications on account of their superior biocompatibility and biodegradability. However, such applications have been limited by their high degradation rate and inadequate antibacterial performance. The present study illustrates the use of a poly-L-lactic acid (PLLA)-åkermanite (AKT)-doxycycline (DOXY) nanofiber coating, created using the electrospinning method, to enhance the corrosion resistance, antibacterial performance, and cytocompatibility of Mg alloys. The experimental results show the PLLA-based nanofiber coatings are smooth and uniform with fiber diameters ranging from 300 to 350 nm. PLLA nanofibers containing AKT have a higher bonding strength (11.8 MPa) than PLLA nanofibers, owing to the significant effect of AKT on the PLLA structure. An in vitro drug release profile of PLLA-AKT nanofibers containing DOXY shows that the nanofibers allow rapid release of drug in the initial stage to provide antibacterial effects as well as sustained release over the long term to prevent infection. The implants coated with PLLA-AKT nanofibers containing DOXY have excellent antibacterial performance against Gram-positive (Staphylococcus aureus, ATCC 12600) and Gram-negative (Escherichia coli, ATCC 9637) bacteria; those coated with PLLA and PLLA-AKT without DOXY have poor antibacterial performance. Cytotoxicity tests show that PLLA and PLLA-AKT nanofiber coatings considerably enhance the cytocompatibility of Mg alloys, while incorporation of a high concentration of DOXY (10% wt.) into the PLLA-AKT coating has adverse effects on cytocompatibility. Thus, PLLA-AKT nanofiber coatings containing low concentrations of DOXY can be employed to control the degradation rate and enhance the antibacterial performance and biocompatibility of Mg alloys as applied to bone infection treatments. The results of this study represent essential information to direct the development of future orthopedic applications

Novel nanostructured baghdadite-vancomycin scaffolds: in-vitro drug release, antibacterial activity and biocompatibility

One of the most important therapeutic and economic concerns regarding surgery, is the occurrence of post-operative infections which leads to an increase in premature failure rate. Therefore, novel nanostructured baghdadite-vancomycin (Ba-Vac) scaffolds were prepared using the space holder method with good mechanical properties and controlled drug release to inhibit post-surgery infections. The results showed that the (Ba-Vac) scaffolds were attained with the pore size of 300–400 µm and total porosity of 80–82% with compressive strength of 0.86–0.88 MPa. In drug release profiles, a burst release was observed for 6 h, followed by a sustained release. Ba-Vac scaffolds presented good antibacterial activity toward Staphylococcus aureus (S. aureus). More attachment and spreading of MG-63 osteoblast cells on the Ba and Ba-(1-3 wt%)Vac scaffolds was also observed in comparison with the Ba-5 wt%Vac scaffold. Therefore, the Ba-(1–3 wt%)Vac scaffold is a good candidate for inhibiting post-surgery infections, as well as for bone tissue engineering

In vitro and in vivo evaluation of chitosan-alginate/gentamicin wound dressing nanofibrous with high antibacterial performance

Wound dressings based on nanofiber polymer scaffolds with good antimicrobial performance and skin reconstruction ability are promising options to thwart wound infection and accelerate wound healing. This paper reports on the synthesis via electrospinning of chitosan-alginate (CS-Alg) nanofiber dressings with various amounts of gentamicin (Gn; 0–10 wt%) as a drug delivery system. Smooth and continuous nanofibers with no obvious beads were created, with increases in the amount of Gn resulting in reduced fiber diameter. Antimicrobial tests showed the Gn-loaded nanofibers had good antibacterial performance as indicated by the inhibition of bacterial growth. CS-Alg nanofibers loaded with higher Gn concentrations exhibited greater antibacterial performance than those with lower Gn concentrations. In vitro cell culture studies demonstrated that CS-Alg wound dressings with 1–3% Gn improved L929 cell attachment and proliferation more than wound dressings with higher Gn concentrations. In vivo experiments revealed that Cs-Alg nanofibers loaded with 3% Gn significantly enhanced skin regeneration in a Balb/C mice model by stimulating the formation of a thicker dermis, increasing collagen deposition, and increasing the formation of new blood vessels and hair follicles. Collectively, Gn-loaded CS-Alg wound dressings can be considered a good candidate for drug delivery systems and skin regeneration applications