scholarly journals Collagen-Carboxymethylcellulose Biocomposite Wound-Dressings with Antimicrobial Activity

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1153
Author(s):  
Ionela Andreea Neacsu ◽  
Sorina-Alexandra Leau ◽  
Stefania Marin ◽  
Alina Maria Holban ◽  
Bogdan-Stefan Vasile ◽  
...  

Microbial infections associated with skin diseases are frequently investigated since they impact on the progress of pathology and healing. The present work proposes the development of freeze-dried, glutaraldehyde cross-linked, and non-cross-linked biocomposite dressings with a porous structure, which may assist the reepithelization process through the presence of collagen and carboxymethylcellulose, along with a therapeutic antimicrobial effect, due to silver nanoparticles (AgNPs) addition. Phisyco-chemical characterization revealed the porous morphology of the obtained freeze-dried composites, the presence of high crystalline silver nanoparticles with truncated triangular and polyhedral morphologies, as well as the characteristic absorption bands of collagen, silver, and carboxymethylcellulose. In vitro tests also assessed the stability, functionality, and the degradability rate of the obtained wound-dressings. Antimicrobial assay performed on Gram-negative (Escherichia coli), Gram-positive (Staphyloccocus aureus) bacteria, and yeast (Candida albicans) models demonstrated that composite wound dressings based on collagen, carboxymethylcellulose, and AgNPs are suitable for skin lesions because they prevent the risk of infection and have prospective wound healing capacity. Moreover, the cell toxicity studies proved that the obtained materials can be used in long time treatments, with no cytotoxic effects.

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 96
Author(s):  
John Jackson ◽  
Helen Burt ◽  
Dirk Lange ◽  
In Whang ◽  
Robin Evans ◽  
...  

The prompt treatment of burn wounds is essential but can be challenging in remote parts of Africa, where burns from open fires are a constant hazard for children and suitable medical care may be far away. Consequently, there is an unmet need for an economical burn wound dressing with a sustained antimicrobial activity that might be manufactured locally at low cost. This study describes and characterizes the novel preparation of a silver nitrate-loaded/poly(vinyl alcohol) (PVA) film. Using controlled heating cycles, films may be crosslinked with in situ silver nanoparticle production using only a low heat oven and little technical expertise. Our research demonstrated that heat-curing of PVA/silver nitrate films converted the silver to nanoparticles. These films swelled in water to form a robust, wound-compatible hydrogel which exhibited controlled release of the antibacterial silver nanoparticles. An optimal formulation was obtained using 5% (w/w) silver nitrate in PVA membrane films that had been heated at 140 °C for 90 min. Physical and chemical characterization of such films was complemented by in vitro studies that confirmed the effective antibacterial activity of the released silver nanoparticles against both gram positive and negative bacteria. Overall, these findings provide economical and simple methods to manufacture stable, hydrogel forming wound dressings that release antibiotic silver over prolonged periods suitable for emergency use in remote locations.


2019 ◽  
Vol 33 (9) ◽  
pp. 1285-1297 ◽  
Author(s):  
Cornelia Wiegand ◽  
Martin Abel ◽  
Uta-Christina Hipler ◽  
Peter Elsner ◽  
Michael Zieger ◽  
...  

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.


2020 ◽  
Vol 1 (2) ◽  
pp. 8-15
Author(s):  
Gislanne Stéphanne Estevam da Silva ◽  
Rivaldo Leon Bezerra Cabral ◽  
Nathalie de Sena Pereira ◽  
José Heriberto Oliveira do Nascimento ◽  
Dany G kramer

Silver nanoparticles (AgNP) can be incorporated into medical devices, such as tissues, to circumvent bacterial resistance such as Klebsiella spp, which can lead to skin and mucosal infections. Thus, the aim of the present study was to synthesize silver nanoparticles for later incorporation into cotton fabrics and in vitro tests against Klebsiella spp. The AgNP colloidal solution was synthesized (AgNO3 - 0.1 mM, 100 mM trisodium citrate, polyvinylpyrrolidone - 0.24 g, H2OH2) and then impregnated into the cotton fabric pretreated with poly diallyl dimethylammonium chloride (PDDA) of 100/500 tissue, shaken for 30 minutes). The material produced was analyzed by the FTIR; DLS and reflectance spectroscopy. The tests of the antimicrobial activities were by the microdilution technique against Klebsiella spp, in tubes containing Brain Heart Infusion (BHI), with the solution of silver (1); Tissue containing AgNP - 4 mm (2); Negative control (3) and positive control - ceftriaxone (4). Regarding MIC, the inhibitory activity occurred of the dilutions between 1/2 and 1/16. The AgNP particles had an average size of 24.75 nm. As synthesized AgNPs demonstrate the excellent antimicrobial activity against Klebsiella spp, with special emphasis on applications in nanotechnology and nanomedicine, targeting multiresistant antibiotic bacteria.


2018 ◽  
Vol 70 (6) ◽  
pp. 1699-1702
Author(s):  
M.A.A. Pereira ◽  
V. Nowosh ◽  
P.N. Suffys ◽  
G.B. Queiroz ◽  
K.M.O. Silva ◽  
...  

ABSTRACT Canine Leproid Granuloma Syndrome (CLGS), also known as canine leprosy, is a cutaneous nodular infectious disease caused by Mycobacterium sp.. Despite being reported worldwide, it is still quite unknown and underdiagnosed. Diagnosis may be achieved by cytopathology or histopathology of skin lesions, but identification of the infectious agent is complex, since bacterial in vitro growth is not possible, relying upon molecular techniques such as PCR to confirm Mycobacterium DNA in the sample. We report a CLGS case in Niteroi, Rio de Janeiro state, Brazil, diagnosed by cytopathology and submitted to molecular identification of the agent. PCR amplification of hsp65 gene was performed and revealed 100% genetic homology to M. murphy strain. This is the first CLGS report with molecular identification in Rio de Janeiro state, and this finding should raise awareness about CLGS as a differential diagnosis among granulomatous skin diseases in this region.


2020 ◽  
Vol 21 (7) ◽  
pp. 2375 ◽  
Author(s):  
Zannatul Ferdous ◽  
Abderrahim Nemmar

Engineered nanomaterials (ENMs) have gained huge importance in technological advancements over the past few years. Among the various ENMs, silver nanoparticles (AgNPs) have become one of the most explored nanotechnology-derived nanostructures and have been intensively investigated for their unique physicochemical properties. The widespread commercial and biomedical application of nanosilver include its use as a catalyst and an optical receptor in cosmetics, electronics and textile engineering, as a bactericidal agent, and in wound dressings, surgical instruments, and disinfectants. This, in turn, has increased the potential for interactions of AgNPs with terrestrial and aquatic environments, as well as potential exposure and toxicity to human health. In the present review, after giving an overview of ENMs, we discuss the current advances on the physiochemical properties of AgNPs with specific emphasis on biodistribution and both in vitro and in vivo toxicity following various routes of exposure. Most in vitro studies have demonstrated the size-, dose- and coating-dependent cellular uptake of AgNPs. Following NPs exposure, in vivo biodistribution studies have reported Ag accumulation and toxicity to local as well as distant organs. Though there has been an increase in the number of studies in this area, more investigations are required to understand the mechanisms of toxicity following various modes of exposure to AgNPs.


2017 ◽  
Vol 43 (2) ◽  
pp. 832-839 ◽  
Author(s):  
Qingjun Pan ◽  
Yongmin Feng ◽  
Yanxia Peng ◽  
Hongjiu Zhou ◽  
Zhenzhen Deng ◽  
...  

Background/Aims: Basophils have been reported to infiltrate skin lesions in various skin diseases, but not in systemic lupus erythematosus (SLE). This study investigated basophil infiltration in SLE and its mechanism. Methods: Twenty newly diagnosed SLE patients and twenty healthy controls were enrolled. Nine SLE patients underwent skin biopsies. Flow cytometric analysis the phenotype of peripheral basophils and their migration rate toward RANTES and MCP-1 were analyzed with the transwell culture system, also the expression of these two chemokines in skin tissue were analyzed with immunohistochemistry. Results: Increased activation and decreased numbers of peripheral basophils were observed in SLE patients compared with controls. Basophil migration into skin lesions of SLE patients were observed, but not in normal skin tissue. This migration was related to the upregulation of chemokine receptors CCR1 and CCR2 on basophils. In vitro studies showed that migration rate toward RANTES and MCP-1 increased significantly in basophils from SLE patients compared with those from controls. Consistently, high levels of RANTES and MCP-1 expression were observed in skin lesions from SLE patients but not in normal skin tissue. Conclusion: Basophil recruitment to skin lesions of SLE patients mediated by CCR1 and CCR2, which may contribute to tissue damage in SLE.


2020 ◽  
Author(s):  
Xuan Lai ◽  
Menglei Wang ◽  
Yixia Zhu ◽  
Xiaoli Feng ◽  
Huimin Liang ◽  
...  

Abstract Background This study aimed to confirm the safety and risk of applying zinc oxide nanoparticles (ZnO NPs) to pathological skin, such as psoriasis-like skin. The majority of previous studies confirmed the safety of applying ZnO NPs to normal skin. However, we know very little about the risks of using sunscreen, cosmetics and topical drugs containing ZnO NPs for individuals with skin diseases. In addition, some studies claimed that ZnO NPs can penetrate normal or pathological skin, and ZnO NPs have frequently been reported to have proinflammatory and lethal effects in vitro. Therefore, it is necessary to evaluate the safety of applying ZnO NPs to pathological skin. Results ZnO NPs passed through gaps between keratinocytes and entered stratum basale of epidermis and dermis in imiquimod (IMQ)-induced psoriasis-like skin lesions. Application of a ZnO NP-containing suspension for 3 connective days delayed the healing of the epidermal barrier; increased the expression levels of inflammatory cytokines; promoted keratinocyte apoptosis and disturbed redox homeostasis. In vitro, ZnO NPs promoted TNF-α, IL-1β and IL-6 secretion and apoptosis of recombinant-human-TNF-α-stimulated HaCaT cells. NF-κB, ERK, p38 and JNK inhibitors blocked ZnO NP-induced inflammation. JSH-23, an inhibitor of the nuclear translocation of p-NF-κB p65, and NAC, an acetylated precursor of L-cysteine, not only inhibited the ZnO NP-induced inflammation but also inhibited apoptosis and cysteine deficiency. Neither erastin nor RSL3 induced p-NF-κB p65 nuclear translocation, but they did reduce cysteine biosynthesis. Additionally, ferropstatin-1, an inhibitor of lipid peroxidation, partially rescued ZnO NP-induced decreases in cell viability and cysteine content. Conclusions ZnO NPs delay the recovery of psoriasis-like skin lesions through promoting inflammation and keratinocyte apoptosis via the nuclear translocation of phosphorylated NF-κB p65 and cysteine deficiency. This work reminds the public that ZnO NPs are not safe for pathological skin, especially in inflammatory skin diseases such as psoriasis, and has revealed a partial mechanism by which ZnO NPs delay the recovery of pathological skin, promoting the appropriate use of ZnO NPs.


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