Burns and chronic wounds present significant challenges in wound management due to risks of infection, excessive inflammation, and prolonged healing. Silver-based treatments have long been central to burn care, but limitations have prompted the exploration of nanocrystalline silver as an alternative, with its nanoscale properties offering distinct benefits. This paper reviews the structure, properties, mechanisms of action, and clinical applications of nanocrystalline silver in burn and general wound management, with particular emphasis on how wound healing processes inform the application of these dressings. Nanocrystalline silver's high surface area-to-volume ratio and crystal structure enhance its antimicrobial and anti-inflammatory efficacy. Nanocrystalline silver's mechanisms of action are disrupting cellular functions, inducing DNA damage, and inhibiting biofilms. Clinical studies demonstrate accelerated healing and reduced inflammation compared to traditional treatments. Whilst nanocrystalline silver dressings are costly, their effectiveness in lowering drug-resistant infections and minimising complications supports a financial case for their use, potentially reducing overall wound care expenses. Considerations of cytotoxicity, allergic reactions, and accessibility underscore the importance of individualised treatment selection based on wound and patient factors. In conclusion, nanocrystalline silver holds substantial promise in burn wound management, and further research is warranted to optimise its therapeutic potential and economic benefits in clinical practice.

Adhesions are fibrous tissue connections which are a common complication of surgical procedures and may be prevented by protecting tissue surfaces and reducing inflammation. The combination of biodegradable polymers and nanocrystalline silver can be used to create an anti-inflammatory gel to be applied during surgery. In this study, sodium hyaluronate and sodium carboxymethyl cellulose were added in concentrations from 0.25% to 1% w/v to aqueous nanocrystalline silver solutions to create viscous gels. Gels were loaded into dialysis cassettes and placed in PBS for 3 days. pH was adjusted using potassium phosphate monobasic and sodium hydroxide. Release of silver into the PBS was measured at several time points. Polymer degradation was compared by measuring the viscosity of the gels before and after the experiment. Gels lost up to 84% of initial viscosity over 3 days and released between 24% and 41% of the added silver. Gels with higher initial viscosity did not have a greater degree of degradation, as measured by percent viscosity reduction, but still resulted in a higher final viscosity. Silver release was not significantly impacted by pH or composition, but still varied between experimental groups.

The vast array of immunoassay technologies used to assess protein interactions is costly or platform-specific. We present a label-free visual interference colour assay (VICA) that quantifies peptide and protein interactions by creating an iridescent surface allowing direct visualisation without spectrophotometric optics or microfluidics. A nanoporous aluminium oxide surface is tuned to match the refractive indices of the overlying protein layers to generate visual interference colours. To functionalise the surface, we created an affinity-capture system using a protein A-carboxyglutamic (GLA) construct that orients antibodies to enhance the signal. Using off-the-shelf antibodies, the platform can isolate analytes in buffer, whole blood, or serum. This surface generates a discernible colour change at concentrations as low as 50 femtomoles/mm2 and can monitor oligomer formation in sequential steps on the same slide. VICA provides comparable kinetic parameters to biolayer interferometry and traditional immunoassays while also allowing characterisation of proteins in large macromolecular complexes.

Solutions containing Ag0 nanoclusters, Ag+1, and higher oxidation state silver, generated from nanocrystalline silver dressings, were anti-inflammatory against porcine skin inflammation. The dressings have clinically-demonstrated broad-spectrum antimicrobial activity, suggesting application of nanosilver solutions in treating pulmonary infection. Nanosilver solutions were tested for antimicrobial efficacy; against HSV-1 and SARS-CoV-2; and nebulized in rats with acute pneumonia. Patients with pneumonia (ventilated), fungal sinusitis, burns plus COVID-19, and two non-hospitalized patients with COVID-19 received nebulized nanosilver solution. Nanosilver solutions demonstrated pH-dependent antimicrobial efficacy; reduced infection and inflammation without evidence of lung toxicity in the rat model; and inactivated HSV-1 and SARS-CoV-2. Pneumonia patients had rapidly reduced pulmonary symptoms, recovering pre-illness respiratory function. Fungal sinusitis-related inflammation decreased immediately with infection clearance within 21 days. Non-hospitalized patients with COVID-19 experienced rapid symptom remission. Nanosilver solutions, due to anti-inflammatory, antiviral, and antimicrobial activity, may be effective for treating respiratory inflammation and infections caused by viruses and/or microbes.

Silver-gold nanocrystalline films were sputtered on HDPE substrates by a physical vapour deposition process using alloys with a nominal composition of 65% silver/35% gold or 35% silver/65% gold by weight, with comparison to a 100% silver target. Novel process conditions were introduced to include both water and oxygen as reactive gases. X-ray diffraction and chemical digests were used to assess the structure and chemical composition of the films. Log reductions and corrected zone of inhibition tests were used to measure the biological properties. Despite a range of physical and chemical properties, biological tests showed that the bactericidal properties of all silver-gold films were comparable with silver-only films in the short term and 65% silver films made with Novel sputtering conditions had comparable bacteriostatic abilities to silver-only over a 7-day period. The benefit of including gold may be seen in future studies of anti-inflammatory activity.

Schizochytrium sp. is a microalga that is known for its high content of oils or lipids. It has a high percentage of polyunsaturated fatty acids in the accumulated oil, especially docosahexaenoic acid (DHA). DHA is an important additive for the human diet. Large-scale production of Schizochytrium sp. can serve as an alternative source of DHA for humans as well as for fish feed, decreasing the burden on aqua systems. Therefore, research on improving the productivity of Schizochytrium attracts a lot of attention. We studied the potential of using low-intensity pulsed ultrasound (LIPUS) in the growth cycle of Schizochytrium sp. in shake flasks. Different intensities and treatment durations were tested. A positive effect of LIPUS on biomass accumulation was observed in the Schizochytrium sp. culture. Specifically, LIPUS stimulation at the ultrasound intensity of 400 mW/cm2 with 20 min per treatment 10 times a day with equal intervals of 2.4 h between the treatments was found to enhance the growth of Schizochytrium biomass most effectively (by up to 20%). Due to the nature of cell division in Schizochytrium sp. which occurs via zoospore formation, LIPUS stimulation was inefficient if applied continuously during all 5 days of the growth cycle. Using microscopy, we studied the interval between zoospore formation in the culture and selected the optimal LIPUS application days (Days 0-1 and Days 4-5 of the 5-day growth cycle). Microscopic images have also shown that LIPUS stimulation enhances zoospore formation in Schizochytrium sp., leading to more active cell division in the culture. This study shows that LIPUS can serve as an additional tool for cost-efficiency improvement in the large-scale production of Schizochytrium as a sustainable and environmentally friendly source of omega-3 (DHA).

Biosensor development has relied on the process of anodization of sputtered aluminum-tantalum thin films to develop specific optical properties for interference color generation. The anodization of thin sputtered films of aluminum (140 nm) on tantalum (230 nm) on silicon was completed in 0.4 M phosphoric acid under potentio-static conditions (4 V) and with various additives: 0.1 M and 0.4 M citric acid, 3% (v/v) and 10% (v/v) of a commercial anodizing solution consisting of glycerol and glycolic acid, and 0.1 M and 0.4 M oxalic acid. The microstructural and optical properties of these films were analyzed using scanning electron microscopy, X-ray diffraction, and ellipsometry. The interference colors produced by the anodic aluminum and tantalum oxides on top of the tantalum metal layer were also observed. The addition of 0.1 M citric acid, 3% (v/v) glycerol and glycolic acid-based solution, and 0.1 or 0.4 M oxalic acid all produced changes to the porous microstructure of the anodic alumina, including lower roughness and more homogeneous surfaces by inhibition of the dissolution from phosphoric acid. Oxalic acid acted as the strongest inhibitor and significantly reduced surface roughness and pore size, increased the composite refractive index of the anodized film, and significantly changed the interference colors compared to films where no additive was used.

This chapter reviews the advances in nanostructured silver materials, focusing on their toxicity, antimicrobial, and antiinflammatory properties. Silver nanomaterials are highly variable; therefore, this chapter begins with an elaboration of the different types of nanostructured silver (e.g., those materials with physical nanodimensions and those with internal structures on the nanoscale). "Nanostructured silver" is clearly defined to avoid any confusion caused by the varied use of the terminology within the field. Processes used to create silver nanomaterials are reviewed, as they have an impact on the biological activity observed. The biological activity of silver nanomaterials has been determined using in vitro and in vivo models, and the appropriateness of these models is discussed relative to human applications, with a focus on the potential of various silver nanotechnologies to impact human health. The pros (antimicrobial and antiinflammatory activity) and cons (toxicity and proinflammatory activity) of these technologies are presented via a detailed examination of the literature. In addition to providing the most recent data on silver nanomaterial activity, this chapter also suggests areas of potential interest for future development and innovation.

Generating renewable energy while sequestering CO 2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii , were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production.

Background is provided on biofilms, including their formation, tolerance mechanisms, structure, and morphology within the context of chronic wounds. The features of biofilms in chronic wounds are discussed in detail, as is the impact of biofilm on wound chronicity. Difficulties associated with the use of standard susceptibility tests (minimum inhibitory concentrations or MICs) to determine appropriate treatment regimens for, or develop new treatments for use in, chronic wounds are discussed, with alternate test methods specific to biofilms being recommended. Animal models appropriate for evaluating biofilm treatments are also described. Current and potential future therapies for treatment of biofilm-containing chronic wounds, including probiotic therapy, virulence attenuation, biofilm phenotype expression attenuation, immune response suppression, and aggressive debridement combined with antimicrobial dressings, are described.

The toxicity mechanism employed by silver nanoparticles against microorganisms has captivated scientists for nearly a decade and remains a debatable issue. The question most frequently asked is whether silver nanoparticles exert specific effects on microorganisms beyond the well-documented antimicrobial activity of Ag+. Here, we study the effects of citrate- (d = 17.5 ± 9.4 nm) and 11-mercaptoundecanoic acid (d = 38.8 ± 3.6 nm)-capped silver nanoparticles on microorganisms belonging to various genera. The antimicrobial effect of Ag+ was distinguished from that of nanosilver by monitoring microbial growth in the presence and absence of nanoparticles and by careful comparison of the responses of equimolar silver nitrate solution. The results show that when using equimolar silver solutions, silver nitrate has higher toxic potential on all microorganisms than both nanoparticles tested. Furthermore, some microorganisms are more susceptible to silver than others and the choice of capping agent is relevant in the toxicity. Atomic force microscopy disclosed that AgNO3 had a destructive effect on algae. The antimicrobial activity of nanosilver could be exploited to prevent microbial colonization of medical devices and to determine the fate of nanoparticles in the environment.

The purpose of this study was to characterize the interactive effects of light and aging on physicochemical properties and antimicrobial activity of nanocrystalline silver wound dressings Acticoat that might find their way into the environment.

Nanocrystalline silver dressings are widely known to be potent antimicrobial and anti‐inflammatory agents and have long been used to treat topical wounds. Gold is known to be a strong anti‐inflammatory agent and has been used in the treatment of rheumatoid arthritis for >70 years. The purpose of this work was to study the effect of incorporating gold into nanocrystalline silver dressings from antimicrobial and anti‐inflammatory perspectives. Gold and silver dressing alloys were created by direct current magnetron sputtering and compared with pure silver nanocrystalline dressings using conventional biological (log reduction and corrected zone of inhibition) and physical (X‐ray diffraction, X‐ray photoelectron spectroscopy, energy‐dispersive X‐ray spectroscopy, atomic absorption spectroscopy, atomic force microscopy and scanning electron microscopy) characterisation techniques. While the gold/silver dressings were slightly weaker antimicrobials than the pure silver nanocrystalline structures, the addition of gold to the nanostructure reduces the minimum crystallite size from 17 to 4 nm. This difference increases the number of grain boundary atoms from 12% to 40% which could augment the anti‐inflammatory properties of the dressings. The formation of gold oxide (Au2O3) was thought to be responsible for the observed decrease in crystallite size.

Fast and accurate determination of lipid content in microalgal cultures is a required step for algal bioprocess development and optimization. An improved high-throughput Nile Red staining protocol using a microplate fluorescence reader is proposed, resulting in an increased correlation coefficient and a reduction in the relative standard deviation of 84% when compared to previously reported staining protocols. Differences in the staining efficacy of Nile Red among different algal strains were observed, even though the performance of the proposed method was found to be satisfactory for the different Trebouxiophyceae and Chlorophyceae microalgal cultures evaluated. Therefore, the proposed Nile Red method should only be used for evaluating lipid content variations in previously standardized strains. BODIPY 505/515 was evaluated as a potential substitute for Nile Red, but was found to be unsuitable as a quantitative stain for algal lipids in the microplate-based staining technique.

The atomic force microscope (AFM) is a powerful instrument for microbiological investigation. It has evolved from an imaging tool used to investigate microbial surfaces at high resolution in their physiological environment into a lab-on-a-tip device, which allows more quantitative analysis of biological samples (from molecules to cells) in aqueous liquids. Atomic force microscopy provides information about the nanoscale architecture of microbes and about the localization and interactions of their individual constituents. Microbial interactions play essential roles in biology, medicine, ecology, biotechnology, food science and contribute to phenomena as varied as bacterial infections, biofilm formation, and bacterial adhesion to surfaces. In this review, we focus on recent developments offered by the rapid advances in AFM imaging and force spectroscopy with emphasizes on microbial research.

The optimization of biomass and oil productivities in heterotrophic cultures of Auxenochlorella protothecoides was achieved using a non-linear model-based approach. A 10-fold increase in the average biomass productivity, and a 16-fold increase in the maximum productivity, was observed with respect to batch cultures as a result of the proposed optimization strategy. Final cell density in the optimized culture was 144 g/L (dry weight), with 49.4%w/w oil content. Maximum lipid productivity was 20.16 g/L d, achieved during the exponential growth phase at an average cell density of 86 g/L. Lipid productivity in the optimized microalgal culture was higher than previously reported values for other oleaginous microorganisms. Oil composition analysis showed that the oil has a high quality as biodiesel precursor. The higher productivity and excellent lipid profile of the optimized microalgal culture make A. protothecoides an exceptional source for biodiesel production and a potential source of single cell oil for other applications.