Viability Of Human Dermal Fibroblasts Research Articles

Stimulated Full-Thickness Cutaneous Wound Healing with Bioactive Dressings of Zinc and Cobalt Ion-Doped Bioactive Glass-Coated Eggshell Membranes in a Diabetic Rabbit Model.

Eggshell membrane-based biomedical applications have recently received great attention for their wound-healing properties. However, there are limited studies on diabetic wound healing. In this regard, we devised four types of composite eggshell membrane mats with nanoscale coatings of bioactive glass/Zn/Co-doped bioactive glass (ESM + BAG, ESM + ZnBAG, ESM + CoBAG, and ESM + ZnCoBAG) as wound-dressing materials for chronic nonhealing diabetic wounds. A detailed study of the physicochemical properties of the mats was conducted. In vitro studies demonstrated cytocompatibility and viability of human dermal fibroblasts on all four types of mats. The cells also attached finely on the mats with the help of cellular extensions, as evident from scanning electron microscopy (SEM) and rhodamine-phalloidin and Hoechst 33342 staining of cellular components. Endowed with bioactive properties, these mats influenced all aspects of full-thickness skin wound healing in diabetic animal model studies. All of the mats, especially the ESM + ZnCoBAG mat, showed the earliest wound closure, effective renewal, and restructuring of the extracellular matrix in terms of an accurate and timely accumulation of collagen, elastin, and reticulin fibers. Hydroxyproline and sulfated glycosaminoglycans were significantly (p < 0.01, p < 0.05) higher in ESM-ZnCoBAG-treated wounds in comparison to ESM-BAG-treated wounds, which suggests that these newly developed mats have potential as an affordable diabetic wound care solution in biomedical research.

Feasibility Study of Neptunia javanica Miq. Extract as an Alternative Medicine for Wound Healing

Neptunia javanica Miq. (NJ) locally known as Kra-Chood, is an unwanted weed that belongs to the family Mimosaceae. This study aims to investigate the feasibility of NJ extract being used as an alternative medicine for wound healing. Preliminary phytochemical analysis was carried out using standard phytochemical screening methods and the NJ ethanolic extract demonstrated alkaloid, flavonoid, tannin, and phenolic compounds. The total phenolic content of the NJ extract was 117.05 ± 0.03 mg GAE/g crude extract, and the total flavonoid contents were 0.63 ± 0.0231 mg RE/g crude extract. The antioxidant activities (IC50) of NJ were 9.29 ± 0.04 µg/mL which is lower than the IC50 of quercetin (38.49 ± 5.38 µg/mL) which represented the potent antioxidation activity of the NJ extract. The metal chelating activity (IC50) of NJ was 1.8584 ± 0.2708 mg/mL. The extract was also found to have α-glucosidase inhibitory and the IC50 was 1.89± 0.19 mg/mL which has a potency equal to 0.13 of the standard acarbose (0.25± 0.09 mg/mL). Moreover, the extract disturbed the human dermal fibroblast viability in a dose-dependent manner. Low concentration of the NJ extract (0.001-0.01 mg/mL) showed no cytotoxicity compared to the negative control (p &lt; 0.05) while high concentration of the extract (0.5 and 1 mg/mL) significantly reduced the cell viability compared to the control (p &lt; 0.05) and the low concentration (p &lt; 0.05). Moreover, the fibroblast exposed to the NJ extract concentration of 0.001-0.01 mg/mL was found to significantly enhance cellular movement and wound gap closure compared to the negative control and gallic acid (p &lt; 0.05). Thus, all these results could develop complementary and integrative benefits, and more investigation in wound healing assay and a subject for should be conducted further studies in clinical trials.

Ultrasonic irradiation enhanced the efficacy of antimicrobial photodynamic therapy against methicillin-resistant Staphylococcus aureus biofilm

Antimicrobial photodynamic therapy (aPDT) is a non-pharmacological antimicrobial regimen based on light, photosensitizer and oxygen. It has become a potential method to inactivate multidrug-resistant bacteria. However, limited by the delivery of photosensitizer (PS) in biofilm, eradicating biofilm-associated infections by aPDT remains challenging. This study aimed to explore the feasibility of combining ultrasonic irradiation with aPDT to enhance the efficacy of aPDT against methicillin-resistant staphylococcus aureus (MRSA) biofilm. A cationic benzylidene cyclopentanone photosensitizer with much higher selectivity to bacterial cells than mammalian cells were applied at the concentration of 10 μM. 532 nm laser (40 mW/cm2, 10 min) and 1 MHz ultrasound (500 mW/cm2, 10 min, simultaneously with aPDT) were employed against MRSA biofilms in vitro. In addition to combined with ultrasonic irradiation and aPDT, MRSA biofilms were treated with laser irradiation only, photosensitizer only, ultrasonic irradiation only, ultrasonic irradiation and photosensitizer, and aPDT respectively. The antibacterial efficacy was determined by XTT assay, and the penetration depth of PS in biofilm was observed using a photoluminescence spectrometer and a confocal laser scanning microscopy (CLSM). In addition, the viability of human dermal fibroblasts (WS-1 cells) after the same treatments mentioned above and the uptake of P3 by WS-1 cells after ultrasonic irradiation were detected by CCK-8 and CLSM in vitro. Results showed that the percent decrease in metabolic activity resulting from the US + aPDT group (75.76%) was higher than the sum of the aPDT group (44.14%) and the US group (9.88%), suggesting synergistic effects. Meanwhile, the diffusion of PS in the biofilm of MRSA was significantly increased by 1 MHz ultrasonic irradiation. Ultrasonic irradiation neither induced the PS uptake by WS-1 cells nor reduced the viability of WS-1 cells. These results suggested that 1 MHz ultrasonic irradiation significantly enhanced the efficacy of aPDT against MRSA biofilm by increasing the penetration depth of PS. In addition, the antibacterial efficacy of aPDT can be enhanced by ultrasonic irradiation, the US + aPDT treatment demonstrated encouraging in vivo antibacterial efficacy (1.73 log10 CFU/mL reduction). In conclusion, the combination of aPDT and 1 MHz ultrasound is a potential and promising strategy to eradicate biofilm-associated infections of MRSA.

New Composite Materials Based on Chitosan Films Reinforced with Chitin Nanofibrils for Cosmetic Application

Bioactive biodegradable chitosan films containing chitin nanofibrils have been developed for use as face masks in cosmetology. It was found that thermal modification of chitosan films promotes the transformation of the polymer into insoluble form without the use of alkali or aldehydes. The structure and properties of the films were studied by IT spectroscopy, atomic force microscopy, thermogravimetric analysis, and X-ray structural analysis. Analysis of infrared (IR) spectra showed that the addition of nanofibrils accelerates the process of thermal transformation in the composite films. This is apparent from the observed increase in the intensity ratio of 1030 cm−1\1580 cm−1 peaks in the spectrum of the thermally treated film (as compared to the spectrum of the initial sample and the spectrum of a chitosan film without chitin nanofibrils). The prepared composite films containing chitin nanofibrils possess improved mechanical characteristics: tensile strength 99 MPa and tensile strain 14%. The tetrazolium bromide (MTT) test revealed good viability of human dermal fibroblasts cultivated in the presence of the conditioned medium obtained after incubation of all types of films in the nutrient medium. The used process of thermal modification of chitosan and composite films (which is efficient and environmentally safe) allows one to prepare bioactive materials for applications in medicine and cosmetology.

Development of nanoclay-based nanocomposite surfaces with antibacterial properties for potential biomedical applications

Biofilm formation on biomedical implant surfaces requires bacterial adhesion, which increases the risk of infection and chronic inflammation. Since intercalation of quaternary ammonium salts (QAS) into montmorillonite (MMT) clay, known as organoclays, has been reported to increase surface broad-spectrum antibacterial properties, we aimed to develop an antibacterial surface composed of thermoplastic polyurethane (TPU) embedded with bentonite and MMT clay containing QAS to prevent initial bacterial attachment. We evaluated its potential application in reducing bacterial adhesion and enhancing bacteria-killing properties using Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Our results demonstrated that the nanoclay-embedded TPU surfaces with QAS significantly reduced the adhesion of E. coli and S. aureus by 68.82% and 65.18%, respectively, compared to the plain TPU surfaces. Additionally, a higher nanoclay concentration coating on the surface could enhance its effectiveness, as shown by 85.34% and 82.74% reduction in E. coli and S. aureus adhesion and killing efficiency. Furthermore, we observed that nanoclay-embedded TPU surfaces had no detrimental effects on the viability of human dermal fibroblasts. Taken together, these techniques could provide novel strategies for inhibiting bacterial adhesion and supporting bacteria killing on biomedical implant surfaces, as the investigated surfaces are simple to synthesize, efficient, and cost-effective.

Predicted Oxaloacetate Activity, Gene Expression And Viability Of Human Dermal Fibroblasts

Rationale — The impact of metabolic pathway intermediates on biological processes and cell viability is a topic of fundamental research: functional potential of low-molecular weight biologically active compounds as regulators of metabolic processes, signal molecules, transmitters of intra- and intercellular signals are of special interest; however, this field remains poorly studied. Objective — To perform computer modeling of oxaloacetate biological activity and to evaluate its effect on human dermal fibroblast culture. Material and Methods — We predicted biological activity of oxaloacetate using in silico methods. The obtained data demonstrated that oxaloacetate could influence proliferative properties and cell culture viability of dermal fibroblasts. We studied metabolic parameters and enzymatic activity in supernatant and cell culture lysate. Cell viability was assessed via methyl tetrazolium test (MTT). Results — We established that oxaloacetate had a stimulating effect on human dermal fibroblast culture. Conclusion — Our results demonstrated the stimulating role of oxaloacetate in the form of changes in the level of metabolites and activity of enzymes, such as gamma-glutamyl transpeptidase (p=0.0019) and glycerol-3-phosphate dehydrogenase (p&lt;0.0001). We also established that oxaloacetate increased the percentage of viable cells, compared with the control (p=0.028).

Nanostructured lipid carriers of alkannins and shikonins: Experimental design, characterization and bioactivity studies

The chiral pair alkannin and shikonin and their ester derivatives (A/S), are lipophilic secondary metabolites possessing a wide spectrum of pharmacological activities. Their incorporation in lipid-based drug delivery systems can enhance their therapeutic efficacy, especially for dermal or transdermal applications. In this work, A/S in the form of oily extracts and isolated mixture of pigments from Alkanna tinctoria roots were entrapped in lipid based nanocarriers for dermal applications. In both cases, Experimental Design was carried out to evaluate the effect of process parameters on mean particle size, ζ-potential and entrapment efficiency, aiming to identify the optimum process conditions. The optimum oily extract loaded liposomes showed a mean particle size of 106 nm, ζ-potential value of −45.1 mV and entrapment efficiency (EE%) up to 72%. On the other hand, the optimum nanocarriers for the incorporation of A/S mixture showed a mean particle size of 138 nm, ζ-potential value of −15.6 mV and EE% up to 56%. The in vitro release profiles for both drug delivery systems were satisfactory and revealed that, in both cases, the release of the active pharmaceutical ingredients from the nanocarriers is controlled by diffusion. Moreover, we evaluated the effect of the optimum formulations on the viability of human dermal fibroblasts and we found that, A/S mixture loaded nanocarriers enhance cell viability. In order to assess the effect of A/S derivatives loaded nanocarriers on human fibroblasts we targeted genes related to the antioxidant cellular response, cell aging and extracellular matrix organization. The findings showed that nanocarriers induced the antioxidant response, presented a positive impact on cells’ longevity and promoted extracellular matrix organization. Based on these findings, formulated nanocarriers can be used as a potential drug delivery system for dermal applications in cosmetic products.

Fabrication and characterization of double-layer asymmetric dressing through electrostatic spinning and 3D printing for skin wound repair

Ideal wound dressings provide optimal microenvironment for the reconstruction of damaged tissue. In this work, we fabricated a bilayer asymmetric dressing to mimic gradient structure of epidermis and dermis of skin by combining electrostatic spinning and 3D printing method with properties including surface hydrophilic and hydrophobic, porosity, mechanical as well as antibacterial properties. The outer layer was prepared by optimized PCL/PLA (PP) via electrostatic spinning to mimick epidermis with water repellency and against bacterial penetration, which has a tensile modulus of 19.69 ± 0.66 MPa. While, the inner layer was 3D printed by optimized sodium alginate/polyvinyl alcohol/chitosan quaternary ammonium salt (SPH). The tensile modulus of SPH with a porosity of 70–90% is 0.82 ± 0.01 MPa, and the water content can be achieved above 85%. The antibacterial efficacy of inner layer was tested against Staphylococcus aureus indicating forming inhibition zone with a diameter of 1.61 ± 0.35 cm. In addition, Cell Counting Kit-8 and Live/Dead assay was used to test the viability of human dermal fibroblasts (HFBS), which showed that PP/SPH with 6% PVA had not significant cytotoxic effects. The double-layer asymmetric dressing meets the requirements of skin mechanical properties and provides an effective repair strategy for clinical skin trauma.

An in vitro assessment of the responses of human dermal fibroblast seeded on 3D printed thermoplastic polyurethane scaffold

Tissue engineering is a multidisciplinary field is an interdisciplinary field for the design of biological substitutes that can improve, restore, and maintain tissue functions. Thermoplastic polyurethanes (TPUs) are linear polymers which are widely used for tissue engineering due to its flexibility in processing methods, biocompatibility and excellent mechanical properties. They are suitable materials for use in three-dimensional (3D) printing. Dermal fibroblasts are mesenchymal cells which play crucial roles in physiological tissue repair. The present study aimed to investigate the viability, proliferation, adhesion, and type IV collagen expression of human dermal fibroblasts (HDFs) seeded on 3D printed TPU scaffolds in vitro. HDFs were seeded on 3D TPU scaffolds or tissue culture polystyrene plates as control and cultured for 1, 3, 7, and 14 days. 3D TPU scaffolds were prepared using a custom made fused deposition modelling printer. The viability and proliferation of cells was analyzed by WST-1 assay on days 1 and 3. The cell adhesion was evaluated by scanning electron microscopy (SEM) on days 1 and 3. The cell morphology was examined by hematoxylin and eosin (H&amp;E) staining. Expression of type IV collagen was analyzed by immunohistochemical (IHC) staining. The viability of HDFs on 3D TPU scaffolds was lower than their control groups on days 1 and 3, slightly higher on day 3. SEM images showed HDF attachment to the 3D TPU scaffold surface with spindle-shaped morphology. H&amp;E staining demonstrated that HDFs on 3D TPU scaffolds showed smaller morphologies on days 7 and 14 compared to days 1 and 3. Type IV collagen staining was more intense in HDFs on 3D TPU scaffolds on day 1, 3, and 7 compared to day 14. In conclusion, our study shows the biocompatibility and the potential applications of 3D printed TPU scaffolds for skin tissue engineering using fibroblasts.

Design and optimization of 3D-bioprinted scaffold framework based on a new natural polymeric bioink.

This aimed at the design and production of engineered 3D scaffold prototypes using a natural polymeric bioink made of chitosan and poly-γ-glutamic acid with a specific focus on 3D-bioprinting process and on 3D framework geometry. Prototypes were produced using a 3D bioprinter exploiting layer-by-layer deposition technology. The 3D scaffold prototypes were fully characterized concerning pore size and size distribution, stability in different experimental conditions, swelling capability, and human dermal fibroblasts viability. Hexagonal framework combined with biopaper allowed stabilizing the 3-layers structure during process manufacturing and during incubation in cell culture conditions. The stability of 3-layers structure was well preserved for 48 h. Crosslinking percentages of 2-layers and 3-layers prototype were 88.2 and 68.39, respectively. The swelling study showed a controlled swelling capability for 2-layers and 3-layers prototype, ∼5%. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed good biocompatibility of 3-layers prototype and their suitability for preserving 48 h cell viability in 3D cultures. Moreover, a significant increment of absorbance value was measured after 48 h, demonstrating cell growth. Bioink obtained combining chitosan and poly-γ-glutamic acid represents a good option for 3D bioprinting. A stable 3D structure was realized by layer-by-layer deposition technology; compared with other papers, the present study succeeded in using medical healthcare-grade polymers, no-toxic crosslinker, and solvents according to ICH Topic Q3C (R4).

Comparison of the Biological Behaviour of Human Dermal Fibroblasts seeded on 3D Printed Polylactic acid, Polycaprolactone and Polyethylene Terephthalate Scaffolds in vitro

Regenerative medicine is a scientific field that improves and repairs diseased and injured tissues. Three-dimensional (3D) printing is an innovative technology that provides a new application field for regenerative medicine. 3D printed scaffolds by programming pore sizes and shapes serve as a temporary basis for cells until the natural extracellular matrix (ECM) is reconstructed. Dermal fibroblasts are mesenchymal cells located in the dermal skin layer that produce and organize ECM components. They play an essential role in skin wound healing and fibrosis. The aim of this study is to analyze the viability, adhesion, distribution, and collagen IV expression of human dermal fibroblasts (HDFs) seeded on 3D printed polylactic acid (PLA), polyethylene terephthalate (PET), and poly-ε-caprolactone (PCL) scaffolds in vitro. HDFs were seeded on scaffolds or tissue culture plastic plates as control and were cultured for 1 and 3 days. 3D PLA, PCL, and PET scaffolds were prepared using a custom made fused deposition modeling printer. The cell viability was measured by WST-1 assay on days 1 and 3. The cell adhesion was evaluated by scanning electron microscopy (SEM). The distribution was analyzed by hematoxylin and eosin (H&amp;E) staining. Collagen IV expression was analyzed by immunohistochemical (IHC) staining. On day 1, the viability of HDFs on the 3D PLA scaffolds was significantly higher than PCL scaffolds. On day 3, the viability of HDFs on 3D PLA and PET scaffolds was significantly higher than PCL scaffolds. SEM images showed that HDFs on 3D PLA scaffolds attached the surfaces, filled the interfiber gaps and maintained their tissue specific morphology on day 3 compared to PCL and PET scaffolds. Histological images stained with H&amp;E demonstrated that the distribution of HDFs on 3D PLA scaffolds was uniform on days 1 and 3. Collagen IV staining was more intense in HDFs on 3D PLA scaffolds on days 1 and 3. This study shows that 3D PLA scaffolds create a appropriate environment for cell viability, adhesion, distribution and may provide a high advantage in skin tissue regeneration.

Fatty acid potassium improves human dermal fibroblast viability and cytotoxicity, accelerating human epidermal keratinocyte wound healing in vitro and in human chronic wounds.

Effective cleaning of a wound promotes wound healing and favours wound care as it can prevent and control biofilms. The presence of biofilm is associated with prolonged wound healing, increased wound propensity to infection, and delayed wound closure. Anionic potassium salts of fatty acids are tested with commonly used anionic surfactants, such as sodium laureth sulphate (SLES) and sodium lauryl sulphate/sodium dodecyl sulphate (SLS/SDS). The normal human dermal cells demonstrated significantly greater viability in fatty acid potassium, including caprylic acid (C8), capric acid (C10), lauric acid (C12), oleic acid (C18:1), and linoleic acid (C18:2), than in SLES or SLS after a 24‐hour incubation. Cytotoxicity by LDH assay in a 5‐minute culture in fatty acid potassium was significantly lower than in SLES or SLS. in vitro wound healing of human epidermal keratinocytes during the scratch assay in 24‐hour culture was more significantly improved by fatty acid treatment than by SLES or SLS/SDS. In a live/dead assay of human epidermal keratinocytes, C8K and C18:1K demonstrated only green fluorescence, indicating live cells, whereas synthetic surfactants, SLES and SLS, demonstrated red fluorescence on staining with propidium iodide, indicating dead cells after SLES and SLS/SDS treatment. Potassium salts of fatty acids are useful wound cleaning detergents that do not interfere with wound healing, as observed in the scratch assay using human epidermal keratinocytes. As potassium salts of fatty acids are major components of natural soap, which are produced by natural oil and caustic potash using a saponification method, this may be clinically important in wound and peri‐wound skin cleaning. In human chronic wounds, natural soap containing fatty acid potassium increased tissue blood flow based on laser speckle flowgraphs after 2 weeks (P < .05), in addition to removing the eschars and debris. Wound cleansing by natural soap of fatty acid potassium is beneficial for wound healing.

Quercetin-gold nanorods incorporated into nanofibers: development, optimization and cytotoxicity.

Herein, a polymeric nanofiber scaffold loaded with Quercetin (Quer)–gold nanorods (GNR) was developed and characterized. Several parameters related to loading Quer into GNR, incorporating the GNR-Quer into polymeric solutions, and fabricating the nanofibers by electrospinning were optimized. GNR-Quer loaded into a polymeric mixture of poly(lactic-co-glycolic acid) (PLGA) (21%) and poloxamer 407 (23%) has produced intact GNR-Quer-nanofibers with enhanced physical and mechanical properties. GNR-Quer-nanofibers demonstrated a slow pattern of Quer release over time compared to nanofibers free of GNR-Quer. Dynamic mechanical thermal analysis (DMTA) revealed enhanced uniformity and homogeneity of the GNR-Quer-nanofibers. GNR-Quer-nanofibers demonstrated a high ability to retain water upon incubation in phosphate buffer saline (PBS) for 24 h compared to nanofibers free of GNR-Quer. A cellular toxicity study indicated that the average cellular viability of human dermal fibroblasts was 76% after 24 h of exposure to the nanofibers containing a low concentration of GNR-Quer.

Novel chitosan and bacterial cellulose biocomposites tailored with polymeric nanoparticles for modern wound dressing development

Dressing biomaterials play a key role in wound management keeping a moisture medium and protecting against external factors. Natural and synthetic materials could be used as dressings where chitosan and bacterial cellulose is one of the most important solutions. These biopolymers have been used for wound dressing based on their non-toxic, biodegradable, and biocompatible features. In this study, biocomposites based on bacterial cellulose and chitosan membranes tailored with antimicrobial loaded poly(N-isopropylacrylamide)/polyvinyl alcohol nanoparticles were prepared. Core-shell polymeric nanoparticles, bacterial cellulose/chitosan membranes, and biocomposites were independently loaded with silver sulfadiazine, a well-known sulfonamide antibacterial agent used in the therapy of mild-to-moderate infections for sensitive organisms. The chemistry, structure, morphology, and size distribution were investigated by Fourier transformed infrared spectroscopy (FTIR-ATR), RAMAN spectroscopy, Scanning electron (SEM) and Transmission electron microscopy (TEM), and Dynamic light scattering (DLS). In vitro release behaviors of silver sulfadiazine from polymeric nanoparticles and biocomposites were investigated. The biological investigations revealed good biocompatibility of both the nanoparticles and the biocomposites in terms of human dermal fibroblasts viability and proliferation potential. Finally, the drug-loaded polymeric biomaterials showed promising characteristics, proving their high potential as an alternative support to develop a biocompatible and antibacterial wound dressing.

In vitro antibacterial activity of extracts from Samoan medicinal plants and their effect on proliferation and migration of human fibroblasts

Ethnopharmacological relevanceThe prevalence of different types of chronic wounds, due to the ageing population and increase incidence of diseases, is becoming a worldwide problem. Various medicinal plants used in folk medicine have demonstrated wound healing and antimicrobial properties, and some of these species are currently used in commercial preparations. Despite the well-documented and rich tradition of the use of local herbs for the treatment of skin injuries in Samoan folk medicine, their wound healing potential has not yet been systematically studied. Aim of the studyInvestigation into the in vitro antibacterial activity of ethanol extracts from 14 medicinal plants used in Samoan traditional medicine for the healing of wounds, burns and sores, and their effects on the proliferation and migration of human fibroblasts. Materials and methodsThe antibacterial activity of these extracts was tested against pathogens associated with infected skin injuries, using the broth microdilution method. The effect on migration, proliferation and viability of human dermal fibroblasts was evaluated using wound healing scratch assay, cell proliferation assay, and thiazolyl blue tetrazolium bromide cytotoxicity test. ResultsThe extracts from Cerbera manghas, Commelina diffusa, Kleinhovia hospita, Mikania micrantha, Omalanthus nutans, Peperomia pellucida, Phymatosorus scolopendria, Piper graeffei, Psychotria insularum, and Schizostachyum glaucifolium inhibited the growth of Staphylococcus aureus at the minimum inhibitory concentration (MIC) of ≥4 μg/mL, whereas C. manghas and P. pellucida produced the same MIC against both Escherichia coli and Pseudomonas aeruginosa. Among the antibacterially active species, C. diffusa, K. hospita, P. scolopendria, P. insularum, and S. glaucifolium did not produce toxicity towards the standard line of normal adult human dermal fibroblasts (IC80 > 128 μg/mL). In addition, extracts from Barringtonia asiatica, C. manghas, M. micrantha, O. nutans, P. insularum, and Piper graeffei stimulated significant migration of dermal fibroblasts, while M. micrantha, O. nutans, and P. insularum did not affect cell proliferation at a concentration of 32 μg/mL. ConclusionsThe results suggest that the above-mentioned species of Samoan medicinal plants can be used for the development of new wound healing agents. However, further phytochemical and pharmacological research is needed regarding the isolation and identification of their active constituents.

Human Dermal Fibroblast Viability and Adhesion on Cellulose Nanomaterial Coatings: Influence of Surface Characteristics.

Biodegradable and renewable materials, such as cellulose nanomaterials, have been studied as a replacement material for traditional plastics in the biomedical field. Furthermore, in chronic wound care, modern wound dressings, hydrogels, and active synthetic extracellular matrices promoting tissue regeneration are developed to guide cell growth and differentiation. Cells are guided not only by chemical cues but also through their interaction with the surrounding substrate and its physicochemical properties. Hence, the current work investigated plant-based cellulose nanomaterials and their surface characteristic effects on human dermal fibroblast (HDF) behavior. Four thin cellulose nanomaterial-based coatings produced from microfibrillar cellulose (MFC), cellulose nanocrystals (CNC), and two TEMPO-oxidized cellulose nanofibers (CNF) with different total surface charge were characterized, and HDF viability and adhesion were evaluated. The highest viability and most stable adhesion were on the anionic CNF coating with a surface charge of 1.14 mmol/g. On MFC and CNC coated surfaces, HDFs sedimented but were unable to anchor to the substrate, leading to low viability.

Production of Active Poly- and Oligosaccharidic Fractions from Ulva sp. by Combining Enzyme-Assisted Extraction (EAE) and Depolymerization.

Data on fractionation and depolymerization of the matrix ulvan polysaccharides, and studies on the biological activities on skin cells, are very scarce. In this work, crude ulvans were produced by using EAE (enzyme-assisted extraction) and compared to maceration (an established procedure). After different fractionation procedures—ethanolic precipitation, dialysis, or ammonium sulfate precipitation—the biochemical composition showed that EAE led to an increased content in ulvans. Coupling EAE to sulfate ammonium precipitation led to protein enrichment. Oligosaccharides were obtained by using radical depolymerization by H2O2 and ion-exchange resin depolymerization. Sulfate groups were partially cleaved during these chemical treatments. The potential bioactivity of the fractions was assessed using a lipoxygenase inhibition assay for anti-inflammatory activity and a WST-1 assay for human dermal fibroblast viability and proliferation. All ulvans extracts, poly- and oligosaccharidic fractions from EAE, expanded the fibroblast proliferation rate up to 62%. Our research emphasizes the potential use of poly- and oligosaccharidic fractions of Ulva sp. for further development in cosmetic applications.

Re-Potentiation of β-Lactam Antibiotic by Synergistic Combination with Biogenic Copper Oxide Nanocubes against Biofilm Forming Multidrug-Resistant Bacteria.

Biofilm-associated tissue and device infection is a major threat to therapy. The present work aims to potentiate β-lactam antibiotics with biologically synthesized copper oxide nanoparticles. The synergistic combination of amoxyclav with copper oxide nanoparticles was investigated by checkerboard assay and time-kill assay against bacteria isolated from a burn wound and a urinary catheter. The control of biofilm formation and extracellular polymeric substance production by the synergistic combination was quantified in well plate assay. The effect of copper oxide nanoparticles on the viability of human dermal fibroblasts was evaluated. The minimum inhibitory concentration and minimum bactericidal concentration of amoxyclav were 70 μg/mL and 140 μg/mL, respectively, against Proteus mirabilis and 50 μg/mL and 100 μg/mL, respectively, against Staphylococcus aureus. The synergistic combination of amoxyclav with copper oxide nanoparticles reduced the minimum inhibitory concentration of amoxyclav by 16-fold against P. mirabilis and 32-fold against S. aureus. Above 17.5 μg/mL, amoxyclav exhibited additive activity with copper oxide nanoparticles against P. mirabilis. The time-kill assay showed the efficacy of the synergistic combination on the complete inhibition of P. mirabilis and S. aureus within 20 h and 24 h, respectively, whereas amoxyclav and copper oxide nanoparticles did not inhibit P. mirabilis and S. aureus until 48 h. The synergistic combination of amoxyclav with copper oxide nanoparticles significantly reduced the biofilm formed by P. mirabilis and S. aureus by 85% and 93%, respectively. The concentration of proteins, carbohydrates, and DNA in extracellular polymeric substances of the biofilm was significantly reduced by the synergistic combination of amoxyclav and copper oxide nanoparticles. The fibroblast cells cultured in the presence of copper oxide nanoparticles showed normal morphology with 99.47% viability. No cytopathic effect was observed. Thus, the study demonstrated the re-potentiation of amoxyclav by copper oxide nanoparticles.

Nigella sativa seed extract applicability in preparations against methicillin-resistant Staphylococcus aureus and effects on human dermal fibroblasts viability

Ethnopharmacological relevanceNigella sativa L. seed extracts and oils have been embraced by traditional medicine of cultures inhabiting Middle East and North Africa for centuries. Among other uses, it has been applied against dermatitis and eczema often worsened by staphylococcal colonization of the skin. Aim of the studyThe study was conducted to evaluate applicability of N. sativa seed extract in antibacterial skin formulations by examination of its activity against methicillin-resistant Staphylococcus aureus as well as cytotoxicity against human dermal fibroblasts. Materials and methodsTwo variants of N. sativa seed extract containing 9.91 and 2.10 % of thymoquinone were prepared by supercritical carbon dioxide extraction. The extracts and standards of their major volatile ingredients; thymoquinone, thymol, p-cymene alongside with the reference antiseptics; chlorquinaldol and a combination of amylmetacresol with 2,4-dichlorobenzyl alcohol were subjected to evaluation of antibacterial efficacy against a collection of Staphylococcus aureus strains. The preparation based on Vaseline containing 1% of N. sativa extract was applied on Mueller-Hinton agar plates and its ability to inhibit S. aureus growth was examined. The MTT assay was employed to study cytotoxic effects of the thymoquinone-rich N. sativa seed extract against HDFa fibroblasts. ResultsN. sativa seed extract and thymoquinone have shown potent bacteriostatic and bactericidal effect against Staphylococcus aureus, including methicillin-resistant strains (MRSA) isolated in Poland. Results suggest that N. sativa seed extract activity against S. aureus should mainly be attributed to thymoquinone, which was effective in concentrations of 4–16 μg/ml. Regarding the activity against S. aureus, thymoquinone was more efficient than a combination of amylmetacresol with 2,4-dichlorobenzyl alcohol and comparable to chlorquinaldol. The Vaseline-based preparation containing N. sativa extract caused growth inhibition comparable to an equally concentrated DMSO solution of the extract. The IC50 of N. sativa extract against HDFa fibroblast was determined at 0.2 mg/ml, which was 2-fold higher than the average MIC and MBC of the extract against S. aureus. ConclusionsThe observed effectiveness of N. sativa seed extracts against bacteria was found to be dominantly dependent on concentration of thymoquinone. Its efficiency against S. aureus isolates as well as results of cytotoxicity examination against human dermal fibroblasts indicate on its applicability as an antibacterial agent for topical use and motivates further research in this area.

Graphene oxide immobilized surfaces facilitate the sustained release of doxycycline for the prevention of implant related infection

Preventing implant-associated infection, which can lead to implant failure and increased medical costs, is one of the biggest challenges in the orthopaedic surgeons. Therefore, the development of stable and highly effective surface modifications to increase the antimicrobial properties of implants is required. In this study, graphene oxide (GO-)-immobilized titanium dioxide (TiO₂) was developed to efficiently carry and release antimicrobial drugs. Firstly, tyramine-conjugated GO (GOTA) was synthesized and immobilized onto the surfaces of TiO₂ through tyrosinase (Tyr)-catalyzed oxidative reaction (GOTA/TiO₂). Doxycycline hyclate (Dox) was then loaded onto GOTA/TiO₂ via non-covalent interactions between GO and Dox (Dox/GOTA/TiO₂), including electrostatic interaction, π-π stacking, hydrophobic interaction, and hydrogen bonds. The amount of loaded drug was able to be controlled, reaching a maximum of 36 μg/cm2. in vitro experiments revealed that the sustained release of Dox from the TiO₂ surfaces continued for over 30 days. Compared with bare TiO₂ and GOTA/TiO2, Dox/GOTA/TiO₂ exhibited superior antibacterial activity against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria, without affecting the viability of human dermal fibroblasts. The obtained results indicated that GO-immobilized TiO₂ is an effective carrier for antimicrobial drug delivery to reduce implant-associated infection through the synergistic antimicrobial effect of GO and the prescribed drugs.