scholarly journals Functionalization of Crosslinked Sodium Alginate/Gelatin Wet-Spun Porous Fibers with Nisin Z for the Inhibition of Staphylococcus aureus-Induced Infections

2021 ◽  
Vol 22 (4) ◽  
pp. 1930
Author(s):  
Natália C. Homem ◽  
Tânia D. Tavares ◽  
Catarina S. Miranda ◽  
Joana C. Antunes ◽  
M. Teresa P. Amorim ◽  
...  

Nisin Z, an amphipathic peptide, with a significant antibacterial activity against Gram-positive bacteria and low toxicity in humans, has been studied for food preservation applications. Thus far, very little research has been done to explore its potential in biomedicine. Here, we report the modification of sodium alginate (SA) and gelatin (GN) blended microfibers, produced via the wet-spinning technique, with Nisin Z, with the purpose of eradicating Staphylococcus aureus-induced infections. Wet-spun SAGN microfibers were successfully produced at a 70/30% v/v of SA (2 wt%)/GN (1 wt%) polymer ratio by extrusion within a calcium chloride (CaCl2) coagulation bath. Modifications to the biodegradable fibers’ chemical stability and structure were then introduced via crosslinking with CaCl2 and glutaraldehyde (SAGNCL). Regardless of the chemical modification employed, all microfibers were labelled as homogeneous both in size (≈246.79 µm) and shape (cylindrical and defect-free). SA-free microfibers, with an increased surface area for peptide immobilization, originated from the action of phosphate buffer saline solution on SAGN fibers, were also produced (GNCL). Their durability in physiological conditions (simulated body fluid) was, however, compromised very early in the experiment (day 1 and 3, with and without Nisin Z, respectively). Only the crosslinked SAGNCL fibers remained intact for the 28 day-testing period. Their thermal resilience in comparison with the unmodified and SA-free fibers was also demonstrated. Nisin Z was functionalized onto the unmodified and chemically altered fibers at an average concentration of 178 µg/mL. Nisin Z did not impact on the fiber’s morphology nor on their chemical/thermal stability. However, the peptide improved the SA fibers (control) structural integrity, guaranteeing its stability for longer, in physiological conditions. Its main effect was detected on the time-kill kinetics of the bacteria S. aureus. SAGNCL and GNCL loaded with Nisin Z were capable of progressively eliminating the bacteria, reaching an inhibition superior to 99% after 24 h of culture. The peptide-modified SA and SAGN were not as effective, losing their antimicrobial action after 6 h of incubation. Bacteria elimination was consistent with the release kinetics of Nisin Z from the fibers. In general, data revealed the increased potential and durable effect of Nisin Z (significantly superior to its free, unloaded form) against S. aureus-induced infections, while loaded onto prospective biomedical wet-spun scaffolds.

Author(s):  
Daniel Díaz-Bandera ◽  
Adriana Villanueva-Carvajal ◽  
Octavio Dublán-García ◽  
Baciliza Quintero-Salazar ◽  
Aurelio Dominguez-Lopez

Author(s):  
Jessica L. Perkins ◽  
Salil Desai ◽  
Benjamin Harrison ◽  
Jagannathan Sankar

This paper investigates the use of calcium alginate microcapsules to transport biomaterials for drug delivery. Rhodamine 6G dye was encapsulated in microcapsules for different formulations of the hydrogels using drop-on-demand printing. An experimental design was constructed to compare the effect of different concentrations of calcium chloride (M) and sodium alginate (% w/v) solutions in addition to the microcapsule diameter on the release kinetics profiles of the microcapsules. The results of these findings provide a basis to identify favorable sizes of microcapsules and concentrations of sodium alginate and calcium chloride solutions for controlled release behavior of microcapsules.


2021 ◽  
Vol 10 (1) ◽  
pp. 860-873
Author(s):  
Parvaneh Mohamadinia ◽  
Navideh Anarjan ◽  
Hoda Jafarizadeh-Malmiri

Abstract Hydrogels are promising drug delivery systems attributable to their unique characteristics such as high hydrophilicity, controllability, biocompatibility, and facile production routines. The aim of this research was the preparation of sodium alginate/acrylic acid (AAc) composite hydrogels conjugated to silver nanoparticles to deliver the cephalexin as a model antibiotic compound. The reduction of silver ions into silver nanoparticles as well as the stabilization of created nanoparticles ensued simultaneously with hydrogel backbone formulation during microwave irradiation and monomer cross-linking processes. The impact of AAc and silver ion concentrations and the radiation time of microwave were then investigated on the main characteristics of hydrogels. The results indicated that the hydrogels’ characteristics could be significantly predicted by studying all independent parameters through various second-order polynomial models. The multiple optimization analysis suggested that the prepared hydrogels using 7.8 g AAc and 1.5 g silver nitrate and 1 min microwave radiation could give the best hydrogels with the highest swelling degree, gel fraction, cephalexin absorption, and antibacterial activity. The morphology and either absorption or release kinetics of cephalexin by the optimum prepared hydrogels were also investigated. No significant differences between the experimental and predicted data confirmed the suitability of the suggested models.


2001 ◽  
Vol 51 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Anandrao R. Kulkarni ◽  
Kumaresh S. Soppimath ◽  
Tejraj M. Aminabhavi ◽  
Walter E. Rudzinski

2014 ◽  
Vol 22 (2) ◽  
pp. 171-176
Author(s):  
Kan WANG ◽  
Zifang WANG ◽  
Ming GAO ◽  
Yaohua HUANG ◽  
Xiaofei HAN ◽  
...  

2021 ◽  
Vol 2 ◽  
pp. 100077
Author(s):  
Sudipta Das ◽  
Arnab Samanta ◽  
Shouvik Mondal ◽  
Debatri Roy ◽  
Amit Kumar Nayak

2021 ◽  
Vol 55 (6) ◽  
pp. 3676-3685
Author(s):  
Yu Wang ◽  
Fang Wang ◽  
Leilei Xiang ◽  
Chenggang Gu ◽  
Marc Redmile-Gordon ◽  
...  

Author(s):  
Lorenzo Lisuzzo ◽  
Giuseppe Cavallaro ◽  
Stefana Milioto ◽  
Giuseppe Lazzara

AbstractIn this work, we investigated the effects of the vacuum pumping on both the loading efficiencies and the release kinetics of halloysite nanotubes filled with drug molecules dissolved in ethanol. As model drugs, salicylic acid and sodium diclofenac were selected. For comparison, the loading of the drug molecules was conducted on platy kaolinite to explore the key role of the hollow tubular morphology on the filling mechanism of halloysite. The effects of the pressure conditions used in the loading protocol were interpreted and discussed on the basis of the thermodynamic results provided by Knudsen thermogravimetry, which demonstrated the ethanol confinement inside the halloysite cavity. Several techniques (TEM, FTIR spectroscopy, DLS and $$\zeta$$ ζ -potential experiments) were employed to characterize the drug filled nanoclays. Besides, release kinetics of the drugs were studied and interpreted according to the loading mechanism. This work represents a further step for the development of nanotubular carriers with tunable release feature based on the loading protocol and drug localization into the carrier. Graphic abstract The filling efficiency of halloysite nanotubes is enhanced by the reduction of the pressure conditions used in the loading protocol.


Sign in / Sign up

Export Citation Format

Share Document