Superabsorbent crosslinked bacterial cellulose biomaterials for chronic wound dressings

AbstractIn this work, we present novel ex situ modification of bacterial cellulose (BC) polymer, that significantly improves its ability to absorb water after drying. The method involves a single inexpensive and easy-to-perform process of BC crosslinking, using citric acid along with catalysts, such as disodium phosphate, sodium bicarbonate, ammonium bicarbonate or their mixtures. In particular, the mixture of disodium phosphate and sodium bicarbonate was the most promising, yielding significantly greater water capacity (over 5 times higher as compared to the unmodified BC) and slower water release (over 6 times as compared to the unmodified BC). Further, our optimized crosslinked BC had over 1.5x higher water capacity than modern commercial dressings dedicated to highly exuding wounds, while exhibiting no cytotoxic effects against fibroblast cell line L929 in vitro. Therefore, our novel BC biomaterial may find application in super-absorbent dressings, designed for chronic wounds with imbalanced moisture level.

Download Full-text

Evaluation of the anti-biofilm activities of bacterial cellulose-tannic acid-magnesium chloride composites using an in vitro multispecies biofilm model

Regenerative Biomaterials ◽

10.1093/rb/rbab054 ◽

2021 ◽

Author(s):

Wei He ◽

Zhaoyu Zhang ◽

Jing Chen ◽

Yudong Zheng ◽

Yajie Xie ◽

...

Keyword(s):

Water Absorption ◽

Bacterial Cellulose ◽

Tannic Acid ◽

Magnesium Chloride ◽

Chronic Wounds ◽

Inhibitory Effect ◽

Wound Dressings ◽

Retention Capacity ◽

Biofilm Model

Abstract Chronic wounds are a serious worldwide problem, which are often accompanied by wound infections. In this study, bacterial cellulose (BC)-based composites introduced with tannic acid (TA) and magnesium chloride (BC-TA-Mg) were fabricated for anti-biofilm activities. The prepared composites' surface properties, mechanical capacity, thermal stability, water absorption and retention property, releasing behavior, anti-biofilm activities, and potential cytotoxicity were tested. Results show that TA and MgCl2 particles closely adhered to the nanofibers of BC membranes, thus increasing surface roughness and hydrophobicity of the membranes. While the introduction of TA and MgCl2 did not influence the transparency of the membranes, making it beneficial for wound inspection. BC-TA and BC-TA-Mg composites displayed increased tensile strength and elongation at break compared to pure BC. Moreover, BC-TA-Mg exhibited higher water absorption and retention capacity than BC and BC-TA, suitable for the absorption of wound exudates. BC-TA-Mg demonstrated controlled release of TA and good inhibitory effect on both singly-cultured S. aureus and P. aeruginosa biofilm and co-cultured biofilm of S. aureus and P. aeruginosa. Furthermore, the cytotoxicity grade of BC-TA-6Mg membrane was eligible based on standard toxicity classifications. These indicated that BC-TA-Mg is potential to be used as wound dressings combating biofilms in chronic wounds.

Download Full-text

In Vitro Investigation of Thiol-Functionalized Cellulose Nanofibrils as a Chronic Wound Environment Modulator

Polymers ◽

10.3390/polym13020249 ◽

2021 ◽

Vol 13 (2) ◽

pp. 249

Author(s):

Anna Blasi-Romero ◽

Carlos Palo-Nieto ◽

Corine Sandström ◽

Jonas Lindh ◽

Maria Strømme ◽

...

Keyword(s):

Protease Activity ◽

Chronic Wounds ◽

Chronic Wound ◽

Cellulose Nanofibrils ◽

Dermal Fibroblasts ◽

Wound Dressings ◽

Thiol Groups ◽

The Stability ◽

Over Time

There is currently a huge need for new, improved therapeutic approaches for the treatment of chronic wounds. One promising strategy is to develop wound dressings capable of modulating the chronic wound environment (e.g., by controlling the high levels of reactive oxygen species (ROS) and proteases). Here, we selected the thiol-containing amino acid cysteine to endow wood-derived cellulose nanofibrils (CNF) with bioactivity toward the modulation of ROS levels and protease activity. Cysteine was covalently incorporated into CNF and the functionalized material, herein referred as cys-CNF, was characterized in terms of chemical structure, degree of substitution, radical scavenging capacity, and inhibition of protease activity. The stability of the thiol groups was evaluated over time, and an in vitro cytotoxicity study with human dermal fibroblasts was performed to evaluate the safety profile of cys-CNF. Results showed that cys-CNF was able to efficiently control the activity of the metalloprotease collagenase and to inhibit the free radical DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), activities that were correlated with the presence of free thiol groups on the nanofibers. The stability study showed that the reactivity of the thiol groups challenged the bioactivity over time. Nevertheless, preparing the material as an aerogel and storing it in an inert atmosphere were shown to be valid approaches to increase the stability of the thiol groups in cys-CNF. No signs of toxicity were observed on the dermal fibroblasts when exposed to cys-CNF (concentration range 0.1–0.5 mg/mL). The present work highlights cys-CNF as a promising novel material for the development of bioactive wound dressings for the treatment of chronic wounds.

Download Full-text

Porous Curdlan-Based Hydrogels Modified with Copper Ions as Potential Dressings for Prevention and Management of Bacterial Wound Infection—An In Vitro Assessment

Polymers ◽

10.3390/polym12091893 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1893

Author(s):

Aleksandra Nurzynska ◽

Katarzyna Klimek ◽

Iga Swierzycka ◽

Krzysztof Palka ◽

Grazyna Ginalska

Keyword(s):

Bacterial Infections ◽

Chronic Wounds ◽

Copper Ions ◽

Bacterial Colonization ◽

Antibacterial Properties ◽

Biological Properties ◽

Wound Dressings ◽

Wound Fluid ◽

Potential Safety

Bacterial infections at the wound site still remain a huge problem for current medicine, as they may lead to development of chronic wounds. In order to prevent such infections, there is a need to use wound dressings that possess ability to inhibit bacterial colonization. In this study, three new curdlan-based biomaterials modified with copper ions were fabricated via simple and inexpensive procedure, and their structural, physicochemical, and biological properties in vitro were evaluated. Received biomaterials possessed porous structure, had ability to absorb high amount of simulated wound fluid, and importantly, they exhibited satisfactory antibacterial properties. Nevertheless, taking into account all evaluated properties of new curdlan-based biomaterials, it seems that Cur_Cu_8% is the most promising biomaterial for management of wounds accompanied with bacterial infections. This biomaterial exhibited the best ability to reduce Escherichia coli and Staphylococcus aureus growth and moreover, it absorbed the highest amount of simulated wound fluid as well as enabled optimal water vapor transmission. Furthermore, Cur_Cu_8% biomaterial possessed the best values of selective indexes, which determine its potential safety in vitro. Thus, Cur_Cu_8% hydrogel may be considered as a promising candidate for management of infected wounds as well as it may constitute a good platform for further modifications.

Download Full-text

Antibiotic-Loaded Psyllium Husk Hemicellulose and Gelatin-Based Polymeric Films for Wound Dressing Application

Pharmaceutics ◽

10.3390/pharmaceutics13020236 ◽

2021 ◽

Vol 13 (2) ◽

pp. 236

Author(s):

Naveed Ahmad ◽

Muhammad Masood Ahmad ◽

Nabil K. Alruwaili ◽

Ziyad Awadh Alrowaili ◽

Fadhel Ahmed Alomar ◽

...

Keyword(s):

Antibacterial Activity ◽

Drug Release ◽

Wound Dressing ◽

Chronic Wounds ◽

Wound Dressings ◽

Patient Comfort ◽

Wound Infections ◽

Psyllium Husk ◽

Antibiotic Release

Wound infections are one of the major reasons for the delay in the healing of chronic wounds and can be overcome by developing effective wound dressings capable of absorbing exudate, providing local antibiotic release, and improving patient comfort. Arabinoxylan (AX) is a major hemicellulose present in psyllium seed husk (PSH) and exhibits promising characteristics for developing film dressings. Herein, AX-gelatin (GL) films were prepared by blending AX, gelatin (GL), glycerol, and gentamicin (antibiotic). Initially, the optimal quantities of AX, GL, and glycerol for preparing transparent, bubble-free, smooth, and foldable AX-GL films were found. Physiochemical, thermal, morphological, drug release, and antibacterial characteristics of the AX-GL films were evaluated to investigate their suitability as wound dressings. The findings suggested that the mechanical, water vapor transmission, morphological, and expansion characteristics of the optimized AX-GL films were within the required range for wound dressing. The results of Fourier-transform infrared (FTIR) analyses suggested chemical compatibility among the ingredients of the films. In in vitro drug release and antibacterial activity experiments, gentamicin (GM)-loaded AX-GL films released approximately 89% of the GM in 24 h and exhibited better antibacterial activity than standard GM solution. These results suggest that AX-GL films could serve as a promising dressing to protect against wound infections.

Download Full-text

Microbial alginate dressings show improved binding capacity for pathophysiological factors in chronic wounds compared to commercial alginate dressings of marine origin

Journal of Biomaterials Applications ◽

10.1177/0885328217702173 ◽

2017 ◽

Vol 31 (9) ◽

pp. 1267-1276 ◽

Cited By ~ 10

Author(s):

Melissa Fischer ◽

Florian Gebhard ◽

Timo Hammer ◽

Christian Zurek ◽

Guido Meurer ◽

...

Keyword(s):

Wound Healing ◽

Chronic Wounds ◽

Azotobacter Vinelandii ◽

Binding Capacity ◽

Matrix Metalloproteases ◽

Wound Dressings ◽

Wound Management ◽

Positive Effects ◽

Alginate Fibres

Marine alginates are well established in wound management. Compared with different modern wound dressings, marine alginates cannot prove superior effects on wound healing. Alginates from bacteria have never been studied for medical applications so far, although the microbial polymer raises expectations for improved binding of wound factors because of its unique O-acetylation. Due to its possible positive effects on wound healing, alginates from bacteria might be a superior future medical product for clinical use. To prove the binding capacity of microbial alginates to pathophysiological factors in chronic wounds, we processed microbial alginate fibres, produced from fermentation of the soil bacterium Azotobacter vinelandii ATCC 9046, into needle web dressings and compared them with commercial dressings made of marine alginate. Four dressings were assessed: Marine alginate dressings containing either ionic silver or zinc/manganese/calcium, and microbial alginate dressings with and without nanosilver. All dressings were tested in an in vitro approach for influence on chronic wound parameters such as elastase, matrix metalloproteases-2, tumour necrosis factor-α, interleukin-8, and free radical formation. Despite the alginate origin or addition of antimicrobials, all dressings were able to reduce the concentration of the proinflammatory cytokines TNF-α and IL-8. However, microbial alginate was found to bind considerable larger amounts of elastase and matrix metalloproteases-2 in contrast to the marine alginate dressings. The incorporation of zinc, silver or nanosilver into alginate fibres did not improve their binding capacity for proteases or cytokines. The addition of nanosilver slightly enhanced the antioxidant capacity of microbial alginate dressings, whereas the marine alginate dressing containing zinc/manganese/calcium was unable to inhibit the formation of free radicals. The enhanced binding affinity by microbial alginate of Azotobacter vinelandii to pathophysiological factors may be interesting to support optimal conditions for wound healing.

Download Full-text

In Vitro Efficacy of Bacterial Cellulose Dressings Chemisorbed with Antiseptics against Biofilm Formed by Pathogens Isolated from Chronic Wounds

International Journal of Molecular Sciences ◽

10.3390/ijms22083996 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3996

Author(s):

Karolina Dydak ◽

Adam Junka ◽

Agata Dydak ◽

Malwina Brożyna ◽

Justyna Paleczny ◽

...

Keyword(s):

Antimicrobial Activity ◽

Bacterial Cellulose ◽

Chronic Wounds ◽

Povidone Iodine ◽

Diffusion Method ◽

Activity Measurement ◽

Antibiofilm Activity ◽

Disc Diffusion ◽

Disc Diffusion Method

Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds.

Download Full-text

PRODUCTION AND CHARACTERIZATION OF BACTERIAL CELLULOSE FROM KOMAGATAEIBACTER XYLINUS ISOLATED FROM HOME-MADE TURKISH WINE VINEGAR

Cellulose Chemistry and Technology ◽

10.35812/cellulosechemtechnol.2021.55.24 ◽

2021 ◽

Vol 55 (3-4) ◽

pp. 243-254

Author(s):

BURAK TOP ◽

ERDAL UGUZDOGAN ◽

NAZIME MERCAN DOGAN ◽

SEVKI ARSLAN ◽

NAIME NUR BOZBEYOGLU ◽

...

Keyword(s):

Bacterial Cellulose ◽

Cytotoxic Effect ◽

Wound Dressings ◽

In Vitro Assays ◽

Water Retention Capacity ◽

Retention Capacity ◽

16S Rdna Sequence Analysis ◽

Wine Vinegar ◽

Komagataeibacter Xylinus

"In this research, bacterial cellulose (BC) was produced from Komagataeibacter xylinus S4 isolated from home-made wine vinegar (Denizli-Çal) and characterized through morphological and biochemical analyses. K. xylinus was identified by 16S rDNA sequence analysis. The wet (51.8-52.8 g) and dry (0.43-0.735 g) weights of the produced BC were measured. The morphology of cellulose pellicles was examined by scanning electron microscopy (SEM) and a dense nanofiber network was observed. TGA analysis showed that the weight loss in the dehydration step in the BC samples occurred between 50 °C and 150 °C, while the decomposition step took place between 215 °C and 228 °C. Also, the cytotoxic effect, moisture content, water retention capacity and swelling behavior of BC were evaluated. In vitro assays demonstrated that BC had no significant cytotoxic effect. It was found that BC had antibacterial and antibiofilm potential (antibacterial effect>antibiofilm effect). All the results clearly showed that the produced BC can be considered as a safe material for different purposes, such as wound dressings."

Download Full-text

Developing Wound Dressings Using 2-deoxy-D-Ribose to Induce Angiogenesis as a Backdoor Route for Stimulating the Production of Vascular Endothelial Growth Factor

International Journal of Molecular Sciences ◽

10.3390/ijms222111437 ◽

2021 ◽

Vol 22 (21) ◽

pp. 11437

Author(s):

Serkan Dikici ◽

Muhammad Yar ◽

Anthony J. Bullock ◽

Joanna Shepherd ◽

Sabiniano Roman ◽

...

Keyword(s):

Small Volume ◽

Chronic Wounds ◽

Low Cost ◽

Wound Dressings ◽

Diabetic Rat ◽

Attractive Alternative ◽

Vascular Endothelial ◽

Improved Stability ◽

Endothelial Growth Factor

2-deoxy-D-Ribose (2dDR) was first identified in 1930 in the structure of DNA and discovered as a degradation product of it later when the enzyme thymidine phosphorylase breaks down thymidine into thymine. In 2017, our research group explored the development of wound dressings based on the delivery of this sugar to induce angiogenesis in chronic wounds. In this review, we will survey the small volume of conflicting literature on this and related sugars, some of which are reported to be anti-angiogenic. We review the evidence of 2dDR having the ability to stimulate a range of pro-angiogenic activities in vitro and in a chick pro-angiogenic bioassay and to stimulate new blood vessel formation and wound healing in normal and diabetic rat models. The biological actions of 2dDR were found to be 80 to 100% as effective as VEGF in addition to upregulating the production of VEGF. We then demonstrated the uptake and delivery of the sugar from a range of experimental and commercial dressings. In conclusion, its pro-angiogenic properties combined with its improved stability on storage compared to VEGF, its low cost, and ease of incorporation into a range of established wound dressings make 2dDR an attractive alternative to VEGF for wound dressing development.

Download Full-text

Antibacterial Effect of Thymol Loaded SBA-15 Nanorods Incorporated in PCL Electrospun Fibers

Nanomaterials ◽

10.3390/nano10040616 ◽

2020 ◽

Vol 10 (4) ◽

pp. 616 ◽

Cited By ~ 4

Author(s):

Enrique Gámez ◽

Hellen Elizondo-Castillo ◽

Jorge Tascon ◽

Sara García-Salinas ◽

Nuria Navascues ◽

...

Keyword(s):

Chronic Wounds ◽

Bacterial Colonization ◽

Release Kinetics ◽

Drug Carrier ◽

Longitudinal Axis ◽

Wound Dressings ◽

Minimal Bactericidal Concentration ◽

Electrospun Fibers ◽

Mesoporous Silicon

For the effective management of infected chronic wounds, the incorporation of antimicrobial drugs into wound dressings can increase their local availability at the infection site. Mesoporous silicon dioxide SBA-15 is an excellent drug carrier with tunable drug release kinetics. In this work, synthesized SBA-15 loaded with the natural antimicrobial compound thymol (THY) was incorporated into polycaprolactone (PCL) electrospun nanofibers to obtain an advanced wound dressing. Rod-shaped particles with internal parallel channels oriented along the longitudinal axis (diameter: 138 ± 30 nm, length: 563 ± 100 nm) were loaded with 70.8 wt.% of THY. Fiber mats were prepared using these particles as nanofillers within polycaprolactone (PCL) electrospun fibers. The resulting mats contained 5.6 wt.% of THY and more than half of this loading was released in the first 7 h. This release would prevent an initial bacterial colonization and also inhibit or eliminate bacterial growth as in vitro shown against Staphylococcus aureus ATCC 25923. Minimal inhibitory concentration (MIC: 0.07 mg/mL) and minimal bactericidal concentration (MBC: 0.11 mg/mL) of released THY were lower than the amount of free THY required, demonstrating the benefit of drug encapsulation for a more efficient bactericidal capacity due to the direct contact between mats and bacteria.

Download Full-text

Crystal and Supramolecular Structure of Bacterial Cellulose Hydrolyzed by Cellobiohydrolase from Scytalidium Candidum 3C: A Basis for Development of Biodegradable Wound Dressings

Materials ◽

10.3390/ma13092087 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2087 ◽

Cited By ~ 1

Author(s):

Lyubov A. Ivanova ◽

Konstantin B. Ustinovich ◽

Tamara V. Khamova ◽

Elena V. Eneyskaya ◽

Yulia E. Gorshkova ◽

...

Keyword(s):

Wound Healing ◽

Specific Surface ◽

Bacterial Cellulose ◽

Supramolecular Structure ◽

Polymer Network ◽

Fold Increase ◽

Wound Dressings ◽

Submicron Particles

The crystal and supramolecular structure of the bacterial cellulose (BC) has been studied at different stages of cellobiohydrolase hydrolysis using various physical and microscopic methods. Enzymatic hydrolysis significantly affected the crystal and supramolecular structure of native BC, in which the 3D polymer network consisted of nanoribbons with a thickness T ≈ 8 nm and a width W ≈ 50 nm, and with a developed specific surface SBET ≈ 260 m2·g−1. Biodegradation for 24 h led to a ten percent decrease in the mean crystal size Dhkl of BC, to two-fold increase in the sizes of nanoribbons, and in the specific surface area SBET up to ≈ 100 m2·g−1. Atomic force and scanning electron microscopy images showed BC microstructure “loosening“after enzymatic treatment, as well as the formation and accumulation of submicron particles in the cells of the 3D polymer network. Experiments in vitro and in vivo did not reveal cytotoxic effect by the enzyme addition to BC dressings and showed a generally positive influence on the treatment of extensive III-degree burns, significantly accelerating wound healing in rats. Thus, in our opinion, the results obtained can serve as a basis for further development of effective biodegradable dressings for wound healing.

Download Full-text