Comparative performance analysis of mussel-inspired polydopamine, polynorepinephrine, and poly-α-methyl norepinephrine in electrochemical biosensors.

Polydopamine (PDA) has garnered significant interest for applications in biosensors, drug delivery, and tissue engineering. However, similar polycatecholamines like polynorepinephrine (PNE) with additional hydroxyl groups and poly-α-methylnorepinephrine (PAMN) with additional hydroxyl and methyl groups remain unexplored in the biosensing domain. This research introduces three innovative biosensing platforms composed of ternary nanocomposite based on reduced graphene oxide (RGO), gold nanoparticles (Au NPs), and three sister polycatecholamine compounds (PDA, PNE, and PAMN). The study compares and evaluates the performance of the three biosensing systems for the ultrasensitive detection of Mycobacterium tuberculosis (MTB). The formation of the nanocomposites was meticulously examined through UV-Visible, Raman, XRD, and FT-IR studies with FE-SEM and HR-TEM analysis. Cyclic voltammetry and differential pulse voltammetry measurements were also performed to determine the electrochemical characteristics of the modified electrodes. Electrochemical biosensing experiments reveal that the RGO-PDA-Au, RGO-PNE-Au, and RGO-PAMN-Au-based biosensors detected target DNA up to a broad detection range of 0.1 × 10-8 to 0.1 × 10-18 M, with a low detection limit (LOD) of 0.1 × 10-18, 0.1 × 10-16, and 0.1 × 10-17 M, respectively. The bioelectrodes were proved to be highly selective with excellent sensitivities of 3.62 × 10-4 mA M-1 (PDA), 7.08 × 10-4 mA M-1 (PNE), and 6.03 × 10-4 mA M-1 (PAMN). This study pioneers the exploration of two novel mussel-inspired polycatecholamines in biosensors, opening avenues for functional nanocoatings that could drive further advancements in this field.

Smart Nanofibrous Hydrogel Wound Dressings for Dynamic Infection Diagnosis and Control: Soft but Functionally Rigid.

Chronic wounds, such as burns and diabetic foot ulcers, pose significant challenges to global healthcare systems due to prolonged hospitalization and increased costs attributed to susceptibility to bacterial infections. The conventional use of antibiotic-loaded and metal-impregnated dressings exacerbates concerns related to multidrug resistance and skin argyrosis. In response to these challenges, our research introduces a unique approach utilizing antibiotic-free smart hydrogel wound dressings with integrated infection eradication and diagnostic capabilities. Electrospinning stands out as a method capable of producing hydrogel nanofibrous materials possessing favorable characteristics for treating wounds and detecting infections under conditions utilizing sustainable materials. In this study, innovative dressings are fabricated through electrospinning polycaprolactone (PCL)/gelatin (GEL) hybrid hydrogel nanofibers, incorporating pDA as a cross-linker, εPL as a broad-spectrum antimicrobial agent, and anthocyanin as a pH-responsive probe. The developed dressings demonstrate exceptional antioxidant (>90% radical scavenging) and antimicrobial properties (95-100% killing). The inclusion of polyphenols/flavonoids and εPL leads to absolute bacterial eradication, and in vitro assessments using HaCaT cells indicate increased cell proliferation, decreased reactive oxygen species (ROS) production, and enhanced cell viability (100% Cell viability). The dressings display notable alterations in color that correspond to different wound conditions. Specifically, they exhibit a red/violet hue under healthy wound conditions (pH 4-6.5) and a green/blue color under unhealthy wound conditions (pH > 6.5). These distinctive color changes provide valuable insights into the versatile applications of the dressings in the care and management of wounds. Our findings suggest that these antibiotic-free smart hydrogel wound dressings hold promise as an effective and sustainable solution for chronic wounds, providing simultaneous infection control and diagnostic monitoring. This research contributes to advancing the field of wound care, offering a potential paradigm shift in the development of next-generation wound dressings.

An insight to the recent advancements in detection of Mycobacterium tuberculosis using biosensors: A systematic review.

Since ancient times, Tuberculosis (TB) has been a severe invasive illness that has been prevalent for thousands of years and is also known as "consumption" or phthisis. TB is the most common chronic lung bacterial illness in the world, killing over 2 million people each year, caused by Mycobacterium tuberculosis (MTB). As per the reports of WHO, in spite of technology advancements, the average rate of decline in global TB infections from 2000-2018 was only 1.6% per year, and the worldwide reduction in TB deaths was only 11%. In addition, COVID-19 pandemic has reversed years of global progress in tackling TB with fewer diagnosed cases. The majority of undiagnosed patients of TB are found in low- and middle-income countries where the GeneXpert MTB/RIF assay and sputum smear microscopy have been approved by the WHO as reference procedures for quickly detecting TB. Biosensors, like other cutting-edge technologies, have piqued researchers' interest since they offer a quick and accurate way to identify MTB. Modern integrated technologies allow for the rapid, low-cost, and highly precise detection of analytes in extremely little amounts of sample by biosensors. Here in this review, we outlined the severity of tuberculosis (TB) and the most recent developments in the biosensors sector, as well as their various kinds and benefits for TB detection. The review also emphasizes how widespread TB is and how it needs accurate diagnosis and effective treatment.

Reduced Graphene Oxide-Polydopamine-Gold Nanoparticles: A Ternary Nanocomposite-Based Electrochemical Genosensor for Rapid and Early Mycobacterium tuberculosis Detection.

Tuberculosis (TB) has been a devastating human illness for thousands of years. According to the WHO, around 10.4 million new cases of tuberculosis are identified every year, with 1.8 million deaths. To reduce these statistics and the mortality rate, an early and accurate TB diagnosis is essential. This study offers a highly sensitive and selective electrochemical biosensor for Mycobacterium tuberculosis (MTB) detection based on a ternary nanocomposite of reduced graphene oxide, polydopamine, and gold nanoparticles (rGO-PDA-AuNP). Avidin-biotin coupling was used to bind the MTB probe DNA onto the rGO-PDA-AuNP modified glassy carbon electrode (ssDNA/avidin/rGO-PDA-AuNP). UV-Visible, Raman, XRD, and TEM were used to evaluate the structural and morphological characteristics of rGO-PDA-AuNP. Furthermore, DNA immobilization is validated using FESEM and FT-IR techniques. The modified electrodes were electrochemically analyzed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV), and the results indicate that the produced electrode can detect target DNA up to 0.1 × 10-7 mM with 2.12 × 10-3 mA µM-1 sensitivity and a response time of 5 s. The constructed genosensor displayed high sensitivity and stability, and it also provides a unique strategy for diagnosing MTB at an early stage. Furthermore, our rGO-PDA-AuNP/GCE-based electrochemical platform has broad potential for creating biosensor systems for detecting various infectious pathogens and therapeutically significant biomarkers.

Bio-inspired polynorepinephrine based nanocoatings for reduced graphene oxide/gold nanoparticles composite for high-performance biosensing of Mycobacterium tuberculosis.

Polydopamine (PDA) has established itself as a promising grafting and coating material, particularly for functional group-deprived electrochemically active nanomaterials such as graphene, MXene, CNT, metal nanoparticles, and so on, and has proven its extensive applicability in the design and development of electrochemical biosensor devices. However, polynorepinephrine (PNE), a sister compound of PDA, having additional -OH groups and greater coating uniformity and biocompatibility, has never been studied in the field of biosensors. Herein, we investigated PNE as a coating material for reduced graphene oxide (RGO) and gold nanoparticles (Au) in order to build an electrochemical genosensor for Mycobacterium tuberculosis (MTB) detection. Biotin-Avidin chemistry was used to covalently immobilize probe DNA (ssDNA) specific to MTB to the nanocomposite surface on glassy carbon electrode (GCE) in order to construct biosensing electrodes. The formation of RGO/PNE and RGO/PNE/Au nanocomposite as well as the immobilization of ssDNA onto the bioelectrodes are both corroborated by UV-Visible, Raman, and XRD studies with FE-SEM and HR-TEM analysis. The electrochemical studies performed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) showed the significant enhancement in charge transfer kinetics of RGO/PNE/GCE and RGO/PNE/Au/GCE electrode compared to GO/GCE electrode. The biosensing investigations performed using ssDNA/avidin/RGO/PNE/Au/GCE bioelectrode showed high sensitivity (2.3 × 10-3 mA µM-1), low detection limit (0.1 × 10-7 µM), broad detection range (0.1 × 10-2 to 0.1 × 10-7 µM) with good selectivity and low response time (5 s) of the developed sensor. In comparison to the analogous RGO/PDA/Au material system, RGO/PNE/Au demonstrated increased enzyme loading, improved electrochemical responsiveness, and superior biosensing performance.

Ternary nanocomposite-based smart sensor: Reduced graphene oxide/polydopamine/alanine nanocomposite for simultaneous electrochemical detection of Cd2+, Pb2+, Fe2+, and Cu2+ ions.

Heavy metal ion (HMI) sensors are the most sought commercial devices for environmental monitoring and food analysis research due to serious health concerns associated with HMI overdosage. Herein, we developed an effective electrochemical sensor for simultaneous detection of four HMI (Cd2+, Pb2+, Fe2+, and Cu2+) using a ternary nanocomposite of reduced graphene oxide functionalized with polydopamine and alanine (ALA/pDA/rGO). Comprehensive spectroscopic and microscopic characterizations were performed to ensure the formation of the ternary nanocomposite. The developed nanocomposite on glassy carbon electrode (GCE) yields >2-fold higher current than GO/GCE electrode with excellent electrochemical stability and charge transfer rate. Using DPV, various chemical and electrochemical parameters, such as supporting electrolyte, buffer pH, metal deposition time, and potential, were optimized to achieve highly sensitive detection of targeted HMI. For Cd2+, Pb2+, Fe2+, and Cu2+ sensing devised sensor exhibited detection limits of 1.46, 2.86, 50.23, and 17.95 ppb and sensitivity of 0.0929, 0.0744, 0.0051, and 0.0394 µA/ppb, respectively, with <6% interference. The sensor worked similarly well for real water samples with HMI. This study demonstrates a novel strategy for concurrently detecting and quantifying multiple HMI in water and soil using a smart ternary nanocomposite-based electrochemical sensor, which can also detect HMI in food samples.

Atomic Cross-Talk at the Interface: Enhanced Lubricity and Wear and Corrosion Resistance in Sub 2 nm Hybrid Overcoats via Strengthened Interface Chemistry.

Friction, wear, and corrosion remain the major causes of premature failure of diverse systems including hard-disk drives (HDDs). To enhance the areal density of HDDs beyond 1 Tb/in2, the necessary low friction and high wear and corrosion resistance characteristics with sub 2 nm overcoats remain unachievable. Here we demonstrate that atom cross-talk not only manipulates the interface chemistry but also strengthens the tribological and corrosion properties of sub 2 nm overcoats. High-affinity (HA) atomically thin (∼0.4 nm) interlayers (ATIs, XHA), namely Ti, Si, and SiNx, are sandwiched between the hard-disk media and 1.5 nm thick carbon (C) overlayer to develop interface-enhanced sub 2 nm hybrid overcoats that consistently outperform a thicker conventional commercial overcoat (≥2.7 nm), with the C/SiNx bilayer overcoat bettering all other <2 nm thick overcoats. These hybrid overcoats can enable the development of futuristic 2-4 Tb/in2 areal density HDDs and can transform various moving-mechanical-system based technologies.

Development of copper impregnated bio-inspired hydrophobic antibacterial nanocoatings for textiles.

Due to their bactericidal and fluid repellent capabilities, antimicrobial textiles with hydrophobic properties have aroused a lot of interest in healthcare, hygiene, air purifiers, water purification systems, food packaging, and other domains. Silver and silver-derived compounds have long been employed in antimicrobial coatings; nevertheless, they are costly, limiting their widespread use. In this work, we combined mussel-inspired polydopamine (pDA) coating chemistry with graphene oxide (GO) and antimicrobial copper compounds (Cu(NO3)2, CuCl2, Cu nanoparticles (CuNPs), and Cu-Carbon nanofibers (Cu-CNF)) to create hydrophobic antimicrobial nanocoatings on cotton fabric. The structural, morphological, wettability, and antibacterial characteristics of the produced coatings were evaluated. The fabric coated with Cu(NO3)2 and CuNPs had good hydrophobicity, which was stabilized for 30 min following GO integration. The coated fabric with GO and CuNPs showed 100% bacterial inhibition for S. aureus and a 99.995% reduction for P. aeruginosa bacteria. Overall, this bioinspired approach to developing antimicrobial coatings on fabric utilizing Cu(NO3)2 and CuNPs with GO shows a lot of promise in preventing the transmission of bacterial and viral infections through contaminated garments and has potential in designing clothing for healthcare settings such as PPEs, gowns, aprons, face mask filters, curtains, and so on.

Patterning at the Resolution Limit of Commercial Electron Beam Lithography.

It has been long known that low molecular weight resists can achieve a very high resolution, theoretically close to the probe diameter of the electron beam lithography (EBL) system. Despite technological improvements in EBL systems, the advances in resists have lagged behind. Here we demonstrate that a low-molecular-mass single-source precursor resist (based on cadmium(II) ethylxanthate complexed with pyridine) is capable of a achieving resolution (4 nm) that closely matches the measured probe diameter (∼3.8 nm). Energetic electrons enable the top-down radiolysis of the resist, while they provide the energy to construct the functional material from the bottom-up─unit cell by unit cell. Since this occurs only within the volume of resist exposed to primary electrons, the minimum size of the patterned features is close to the beam diameter. We speculate that angstrom-scale patterning of functional materials is possible with single-source precursor resists using an aberration-corrected electron beam writer with a spot size of ∼1 Å.

Recent advances in copper and copper-derived materials for antimicrobial resistance and infection control.

Antibacterial properties of copper have been known for ages. With the rise of antimicrobial resistance (AMR), hospital-acquired infections, and the current SARS-CoV-2 pandemic, copper and copper-derived materials are being widely researched for healthcare ranging from therapeutics to advanced wound dressing to medical devices. We cover current research that highlights the potential uses of metallic and ionic copper, copper alloys, copper nanostructures, and copper composites as antibacterial, antifungal, and antiviral agents, including those against the SARS-CoV-2 virus. The applications of copper-enabled engineered materials in medical devices, wound dressings, personal protective equipment, and self-cleaning surfaces are discussed. We emphasize the potential of copper and copper-derived materials in combating AMR and efficiently reducing infections in clinical settings.

Design and evaluation of pyrimidine derivatives as potent inhibitors of ABCG2, a breast cancer resistance protein.

The protein ATP-binding cassette subfamily G member 2 (ABCG2) is one of the major factors behind multidrug resistance (MDR) in breast cancer. We performed three-dimensional quantitative structure-activity relationship (3D-QSAR) modelling, docking, and molecular dynamics (MD) simulation to design pyrimidine-based ABCG2 antagonists. The developed QSAR model (r 2 = 0.92, q 2 = 0.82, and good cross-validated r 2 = 0.73) dictate requirement of electrostatic, and hydrophobic fields for modulating bioactivity. Based on this rationale, we designed and screened 1010 new compounds, among them 2 (ND-510 and ND-500) exhibit excellent drug-like features. Comparative molecular docking, MM/GBSA and ADMET profiles were determined to understand the interactive poses, affinity, and drug-likeness of the designed compounds. Furthermore, MD simulations were performed with the ABCG2 receptor, and the results were compared with the two earlier synthesized active compounds. The outcomes of the study will help researchers to develop new antagonists for treatment of MDR breast cancer. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03231-1.

Unusual High Hardness and Load-Dependent Mechanical Characteristics of Hydrogenated Carbon-Nitrogen Hybrid Films.

Mechanical components are exposed to a rigorous environment in a number of applications including engineering, aerospace, and automobiles. Thus, their service lifetime and reliability are always on the verge of risk. Protective coatings with high hardness are required to enhance their service lifetime and minimize the replacement cost and waste burden. Hydrogenated amorphous carbon including nitrogen-incorporated films, that are commonly deposited by plasma-enhanced chemical vapor deposition, are widely used for commercial protective coating applications. However, their mechanical hardness still falls into the moderate hard regime. This needs to be substantially enhanced for advanced applications. Here, we report the synthesis of very hard nanostructured hydrogenated carbon-nitrogen hybrid (n-C:H:N) films. The optimized n-C:H:N film displays a hardness of about 36 GPa, elastic modulus of 360 GPa, and reasonably good elastic recovery (ER) of 62.7%. The mechanical properties of n-C:H:N films are further tailored when nitrogen pressure is tuned during the growth. The realized remarkably improved mechanical properties are correlated with the films' structural properties and experimental growth conditions. We also conducted density functional theory calculations that show the trend for the elastic modulus of the amorphous carbon films with varying nitrogen concentrations matches well with experimentally measured values. Finally, we probed load-dependent mechanical properties of n-C:H:N films and found an anomalous behavior; some of the mechanical parameters, for instance, ER, reveal an irregular trend with indentation load, which we explain in the framework of the film-substrate composite concept. Overall, this work uncovers many unknown and exciting mechanical phenomena that could pave the way for new technological developments.

Carbon-Based Sorbents for Hydrogen Storage: Challenges and Sustainability at Operating Conditions for Renewable Energy.

It is estimated that all fossil fuels will be depleted by 2060 if we continue to use them at the present rate. Therefore, there is an unmet need for an alternative source of energy with high calorific value. In this regard, hydrogen is considered the best alternative renewable fuel that could be used in practical conditions. Accordingly, researchers are looking for an ideal hydrogen storage system under ambient conditions for feasible applications. In many respects, carbon-based sorbents have emerged as the best possible hydrogen storage media. These carbon-based sorbents are cost-effective, eco-friendly, and readily available. In this Review, the present status of carbon-based materials in promoting solid-state hydrogen storage technologies at the operating temperature and pressure was reported. Experimental studies have shown that some carbon-based materials such as mesoporous graphene and doped carbon nanotubes may have hydrogen storage uptake of 3-7 wt %, while some theoretical studies have predicted up to 13.79 wt % of hydrogen uptake at ambient conditions. Also, it was found that different methods used for carbon materials synthesis played a vital role in hydrogen storage performance. Eventually, this Review will be helpful to the scientific community for finding the competent material and methodology to investigate the existing hydrogen uptake issues at operating conditions.

2D Materials-Based Aptamer Biosensors: Present Status and Way Forward.

Current advances in constructing functional nanomaterials and elegantly designed nanostructures have opened up new possibilities for the fabrication of viable field biosensors. Two-dimensional materials (2DMs) have fascinated much attention due to their chemical, optical, physicochemical, and electronic properties. They are ultrathin nanomaterials with unique properties such as high surface-to-volume ratio, surface charge, shape, high anisotropy, and adjustable chemical functionality. 2DMs such as graphene-based 2D materials, Silicate clays, layered double hydroxides (LDHs), MXenes, transition metal dichalcogenides (TMDs), and transition metal oxides (TMOs) offer intensified physicochemical and biological functionality and have proven to be very promising candidates for biological applications and technologies. 2DMs have a multivalent structure that can easily bind to single-stranded DNA/RNA (aptamers) through covalent, non-covalent, hydrogen bond, and π-stacking interactions, whereas aptamers have a small size, excellent chemical stability, and low immunogenicity with high affinity and specificity. This review discussed the potential of various 2D material-based aptasensor for diagnostic applications, e.g., protein detection, environmental monitoring, pathogens detection, etc.

Angstrom-Scale Transparent Overcoats: Interfacial Nitrogen-Driven Atomic Intermingling Promotes Lubricity and Surface Protection of Ultrathin Carbon.

Lubricity, a phenomenon which enables the ease of motion of objects, and wear resistance, which minimizes material damage or degradation, are important fundamental characteristics for sustainable technology developments. Ultrathin coatings that promote lubricity and wear resistance are of huge importance for a number of applications, including magnetic storage and micro-/nanoelectromechanical systems. Conventional ultrathin coatings have, however, reached their limit. Graphene-based materials that have shown promise to reduce friction and wear have many intrinsic limitations such as high temperature and substrate-specific growth. To address these concerns, a great deal of research is currently ongoing to optimize graphene-based materials. Here we discover that angstrom-thick carbon (8 Å) significantly reduces interfacial friction and wear. This lubricant shows ultrahigh optical transparency and can be directly deposited on a wide range of surfaces at room temperature. Experiments combined with molecular dynamics simulations reveal that the lubricating efficacy of 8 Å carbon is further improved via interfacial nitrogen.

Keratinophilic fungi from the feathers of Emu (Dromaius novaehollandiae) in Maharastra India.

A total of 70 feathers samples of Emu (Dromaius novaehollandiae) were collected from 7 Emu farms situated at two districts (Raigad and Thane) of Maharashtra (India) and screened for resident keratinophilic fungi. Among them, 44 isolates were recovered and identified by evaluating characteristic macro- and micro-morphological features. Further gene products corresponding to the ITS1-5.8S-ITS2 rDNA region from all isolates were amplified and sequenced. Homology search was performed using BLAST program against non-redundant nucleotide database, and significantly matched DNA sequences deposited to the NCBI Gene Bank for reference purposes. Eight identified fungal species belongs to 7 different genera named as Aphanoascus terreus Ac_MW577456 (21.43%), Microsporum gypseum Ac_MW580920 (14.29%), Ctenomyces serratus Ac_MW577459 (10.0%), Uncinocarpus orissi Ac_MW577461 (5.17%), Aphanoascus verrucosus Ac_MW577458 (4.29%), Gymnascella dankaliensis Ac_MW577460 (2.86%), Gymnoascoideus petalosporus Ac_MW577462 (2.86%) and Arthroderma tuberculatum Ac_MW577457 (1.43%).

Triple-Smart Eco-Friendly Chili Anthracnose Control Agro-Nanocarrier.

Pesticide leaching and soil contamination are major issues in the present agriculture formulations. Hence, here 2D graphene oxide in combination with cationic, anionic, or nonionic polymers were tested for runoff resistance and targeted release behavior. Cationic polymer supplemented the binding of rGO on leaf surface by 30% more than control and reduced off-target leaching in soil by 45% more than control. Further, to enhance the fruit rot control caused by Colletotrichum capsici in chili crop, the rGO was decorated with Cu2-xSe nanocrystals, which provided combined disease control with captan. The chitosan coating in the nanocomposite added targeted pH-responsive fungal inhibition behavior and could reduce the C. capsici growth by ∼1/2 times compared to captan control.

Lightweight carbon-red mud hybrid foam toward fire-resistant and efficient shield against electromagnetic interference.

Lightweight, porous, high-performance electromagnetic interference (EMI) shielding and fire-resistant materials are highly demanded in aerospace and defense applications. Due to the lightweight, open porosity and high surface area, carbon foam has been considered as one of the most promising candidates for EMI shielding applications. In the present investigation, we demonstrate the development of novel carbon-red mud hybrid foams with excellent EMI shielding effectiveness (SE). The carbon-red mud hybrid foams are prepared using phenolic resin as a carbon source and red mud (industrial waste) as filler. We observed that the inclusion of red mud in carbon-red mud hybrid foams significantly enhances their dielectric, magnetic, EMI shielding and thermal properties. The EMI shielding results show that absorption is the main contributor to the total EMI SE. The maximum total EMI shielding effectiveness is achieved to be 51.4 dB in the frequency range of 8.2-12.4 GHz for carbon-red mud hybrid foam having 20 wt. % of red mud. The CF-RM20 also showed excellent fire resistance and high thermal stability at elevated temperatures.

Wound healing properties of magnesium mineralized antimicrobial nanofibre dressings containing chondroitin sulphate - a comparison between blend and core-shell nanofibres.

The development of antimicrobial nanofibre dressings that can protect the injured tissues from commensal pathogens while promoting tissue regeneration finds enormous potential in plastic and reconstructive surgery practices. To achieve this goal, we investigated the effect of chondroitin sulphate on the morphology, mechanical properties, wettability and biocompatibility of polydopamine crosslinked electrospun gelatin nanofibres containing mineralized magnesium. To extend the durability of dressings, we prepared composite dressings containing polycaprolactone (PCL) and gelatin as blend or core-shell nanofibres. Nanofibre blends presented greater tensile strength and stretchability, while core-shell nanofibres displayed superior photoluminescent properties. In a porcine model of cutaneous burn injury, both the blend and core-shell nanofibre dressings displayed improved re-epithelialization, wound closure and clinical outcome in comparison to untreated burns. Histology of the biopsied tissues indicated smooth regeneration and collagen organization of the burns treated with core-shell nanostructures than untreated burns. This study compared the physico-chemical and biological properties of composite nanofibres that are capable of accelerating burn wound healing and possess antimicrobial properties, highlighting their potential as wound dressings and skin substitutes.

Multifunctional Antimicrobial Nanofiber Dressings Containing ε-Polylysine for the Eradication of Bacterial Bioburden and Promotion of Wound Healing in Critically Colonized Wounds.

Bacterial colonization of acute and chronic wounds is often associated with delayed wound healing and prolonged hospitalization. The rise of multi-drug resistant bacteria and the poor biocompatibility of topical antimicrobials warrant safe and effective antimicrobials. Antimicrobial agents that target microbial membranes without interfering with the mammalian cell proliferation and migration hold great promise in the treatment of traumatic wounds. This article reports the utility of superhydrophilic electrospun gelatin nanofiber dressings (NFDs) containing a broad-spectrum antimicrobial polymer, ε-polylysine (εPL), crosslinked by polydopamine (pDA) for treating second-degree burns. In a porcine model of partial thickness burns, NFDs promoted wound closure and reduced hypertrophic scarring compared to untreated burns. Analysis of NFDs in contact with the burns indicated that the dressings trap early colonizers and elicit bactericidal activity, thus creating a sterile wound bed for fibroblasts migration and re-epithelialization. In support of these observations, in porcine models of Pseudomonas aeruginosa and Staphylococcus aureus colonized partial thickness burns, NFDs decreased bacterial bioburden and promoted wound closure and re-epithelialization. NFDs displayed superior clinical outcome than standard-of-care silver dressings. The excellent biocompatibility and antimicrobial efficacy of the newly developed dressings in pre-clinical models demonstrate its potential for clinical use to manage infected wounds without compromising tissue regeneration.