scholarly journals Bioactive 3D-Shaped Wound Dressings Synthesized from Bacterial Cellulose: Effect on Cell Adhesion of Polyvinyl Alcohol Integrated In Situ

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Marlon Osorio ◽  
Jorge Velásquez-Cock ◽  
Luz Marina Restrepo ◽  
Robín Zuluaga ◽  
Piedad Gañán ◽  
...  

We investigated wound dressing composites comprising fibrils of bacterial cellulose (BC) grown by fermentation in the presence of polyvinyl alcohol (PVA) followed by physical crosslinking. The reference biointerface, neat BC, favoured adhesion of fibroblasts owing to size exclusion effects. Furthermore, it resisted migration across the biomaterial. Such effects were minimized in the case of PVA/BC membranes. Therefore, the latter are suggested in cases where cell adhesion is to be avoided, for instance, in the design of interactive wound dressings with facile exudate control. The bioactivity and other properties of the membranes were related to their morphology and structure and considered those of collagen fibres. Bioactive materials were produced by simple 3D templating of BC during growth and proposed for burn and skin ulcer treatment.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jian Li ◽  
Qun Zhang ◽  
Minjing Xu ◽  
Changzhu Wu ◽  
Ping Li

Nanoparticle metal oxides are emerging as a new class of important materials in medical, agricultural, and industrial applications. In this context, free zinc oxide (ZnO) nanoparticles (NPs) have been increasingly shown with broad antimicrobial activities. However, biological properties of immobilized ZnO NPs on matrixes like nanofibrous membranes are still limited. In this study, in situ synthesized ZnO NPs/polyvinyl alcohol (PVA) nanofibrous membranes were fabricated by electrospinning with different zinc acetate concentrations. Characterization results indicated that, with 5 mM zinc acetate, uniform size ZnO NPs (~40 nm) were formed and evenly distributed on the membrane surface. The surfaces became more hydrophobic with higher concentration of zinc acetate. ZnO NPs/PVA nanofibrous membranes showed a broad spectrum of antimicrobial activities and cell adhesion inhibiting effects against four microorganisms including Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli, fungi Candida albicans, and spores of Aspergillus niger. Our data revealed that the major antimicrobial mechanism could be attributed to cell membrane damage and cellular internalization of ZnO NPs, while the hydrophobic surface of the membrane primarily contributed to the cell adhesion inhibition. This study suggests that ZnO NPs/PVA nanofibrous membranes could potentially be used as an effective antimicrobial agent to maintain agricultural and food safety.


Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 624 ◽  
Author(s):  
Selestina Gorgieva

The unique pool of features found in intracellular and extracellular bacterial biopolymers attracts a lot of research, with bacterial cellulose (BC) being one of the most versatile and common. BC is an exopolysaccharide consisting solely of cellulose, and the variation in the production process can vary its shape or even its composition when compounding is applied in situ. Together with ex situ modification pathways, including specialised polymers, particles or exclusively functional groups, BC provides a robust platform that yields complex multifunctional compounds that go far beyond ultra-high purity, intrinsic hydrophilicity, mechanical strength and biocompatibility to introduce bioactive, (pH, thermal, electro) responsive, conductive and ‘smart’ properties. This review summarises the research outcomes in BC-medical applications, focusing mainly on data from the past decade (i.e., 2010–2020), with special emphasis on BC nanocomposites as materials and devices applicable in medicine. The high purity and unique structural/mechanical features, in addition to its capacity to closely adhere to irregular skin surfaces, skin tolerance, and demonstrated efficacy in wound healing, all stand as valuable attributes advantageous in topical drug delivery. Numerous studies prove BC compatibility with various human cells, with modifications even improving cell affinity and viability. Even BC represents a physical barrier that can reduce the penetration of bacteria into the tissue, but in its native form does not exhibit antimicrobial properties, therefore carious modifications have been made or specific compounds added to confer antimicrobial or anti-inflammatory properties. Progress in the use of BC-compounds as wound dressings, vascular grafts, and scaffolds for the treatment of cartilage, bone and osteochondral defects, the role as a basement membrane in blood-brain barrier models and many more are discussed to particular extent, emphasising the need for BC compounding to meet specific requirements.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 713
Author(s):  
Nina Melnikova ◽  
Alexander Knyazev ◽  
Viktor Nikolskiy ◽  
Peter Peretyagin ◽  
Kseniia Belyaeva ◽  
...  

A design of new nanocomposites of bacterial cellulose (BC) and betulin diphosphate (BDP) pre-impregnated into the surface of zinc oxide nanoparticles (ZnO NPs) for the production of wound dressings is proposed. The sizes of crystalline BC and ZnO NPs (5–25%) corresponded to 5–6 nm and 10–18 nm, respectively (powder X-ray diffractometry (PXRD), Fourier-infrared (FTIR), ultraviolet (UV), atomic absorption (AAS) and photoluminescence (PL) spectroscopies). The biological activity of the wound dressings “BC-ZnO NPs-BDP” was investigated in rats using a burn wound model. Morpho-histological studies have shown that more intensive healing was observed during treatment with hydrophilic nanocomposites than the oleophilic standard (ZnO NPs-BDP oleogel; p < 0.001). Treatment by both hydrophilic and lipophilic agents led to increases in antioxidant enzyme activity (superoxide dismutase (SOD), catalase) in erythrocytes and decreases in the malondialdehyde (MDA) concentration by 7, 10 and 21 days (p < 0.001). The microcirculation index was restored on the 3rd day after burn under treatment with BC-ZnO NPs-BDP wound dressings. The results of effective wound healing with BC-ZnO NPs-BDP nanocomposites can be explained by the synergistic effect of all nanocomposite components, which regulate oxygenation and microcirculation, reducing hypoxia and oxidative stress in a burn wound.


2021 ◽  
Vol 290 ◽  
pp. 129505
Author(s):  
Haining Wang ◽  
Birong Tian ◽  
Fu Wang ◽  
Jinyun Zhang ◽  
Zhaofeng Wang

2018 ◽  
Vol 33 (2) ◽  
pp. 180-197 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli

Pristine mesoporous diatomite was employed to prepare polystyrene/diatomite composites. Diatomite platelets were used for in situ polymerization of styrene by atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. X-Ray fluorescence spectrometer analysis and thermogravimetric analysis (TGA) were employed for evaluating some inherent properties of pristine diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Linear increase of ln ( M0/M) with time for all the samples shows that polymerization proceeds in a living manner. Addition of 3 wt% pristine mesoporous diatomite leads to an increase of conversion from 72% to 89%. Molecular weight of polystyrene chains increases from 11,326 g mol−1 to 14134 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.13 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 81.9°C to 87.1°C by adding 3 wt% of mesoporous diatomite platelets.


2018 ◽  
Vol 57 (50) ◽  
pp. 17048-17057 ◽  
Author(s):  
Yanping Huang ◽  
Nianhua Dan ◽  
Weihua Dan ◽  
Weifeng Zhao ◽  
Zhongxiang Bai ◽  
...  

Author(s):  
Sanket Kumar ◽  
Mahesh Singh ◽  
Babulal Patel

Peptic ulcer, it is the most common type of stomach disease, according to the American Gastroenterology Association. “We know that ulcers occur because there has been a disruption in the balance of factors that injure the digestive tract and those factors that protect it from injury,” The present investigation deal with the formulation, optimization and evaluation of sodium alginate based in situ gel of ranitidine hydrochloride (R-HCl) in ulcer treatment. The in-situ formulation are homogenous liquid when administration orally and become gel at the contact site. The evaluation of the formulation is dependent upon accurate results obtained by analytical method used during the study. Accurate results require the use of standard and a calibration procedure. Hence, standard plots of Ranitidine hydrochloride were prepared in (0.1N HCL, pH 1.2) solutions. Two, sodium alginate and calcium carbonate used as a polymer and cross-linking agent respectively in the formulation of in-situ gel. From the IR studies it may be concluded that the drug and carriers used undergo physical interaction there is no chemical change, and thus the gelling agent, cross-linking agent and other excipient is suitable for formulation of in-situ gel of ranitidine hydrochloride. Indicate that the formulation, DKF9 which was prepared by the Sodium alginate (2 gm) with Ranitidine Hydrochloride showed minimum drug release (sustained drug release) after 8 hrs. It can be concluded that the In-situ gel was beneficial for delivering the drug which needs sustained release to achieve the slow action. Keywords: In-situ gel, Peptic Ulcer, Ranitidine Hydrochloride (R-HCl), Sodium alginate.


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