Inherent Antimicrobial Properties Research Articles

Harnessing Plant-Based Nanoparticles for Combatting Multidrug-Resistant Bacteria

The emergence of multidrug-resistant organisms poses a significant challenge to public health worldwide. In response, plant-based nanoparticles have garnered attention for their potential as novel antimicrobial agents. These nanoparticles are derived from various plant sources and exhibit inherent antimicrobial properties due to their phytochemical composition. Nanoparticles synthesized from spinach (Spinacia oleracea) and orange (Citrus sinensis) extracts, loaded with salts of Cu and Zn, were evaluated for their antimicrobial activity against multidrug-resistant bacteria. Antimicrobial efficacy was assessed through agar well diffusion assays against clinically relevant multidrug-resistant bacterial strains of Pseudomonas aeruginosa MTCC 74, Staphylococcus aureus MTCC 902, Klebsiella pneumoniae MTCC 661. The nanoparticles exhibited potent antimicrobial effects, significantly inhibiting the growth of tested bacteria even when compared to commercially available antibiotics. These findings highlight the potential of plant-based nanoparticles loaded with Cu and Zn salts as effective agents against multidrug-resistant bacteria, offering a promising avenue for future antimicrobial therapies.

Effects of Metal and Metal Oxide Nanoparticles against Biofilm-Forming Bacteria: A systematic Review.

Biofilm formation by bacteria poses a significant challenge across diverse industries, displaying resilience against conventional antimicrobial agents. Nanoparticles emerge as a promising alternative for addressing biofilm-related issues. This review aims to assess the efficacy of metal and metal oxide nanoparticles in inhibiting or disrupting biofilm formation by various bacterial species. It delineates trends, identifies gaps, and outlines avenues for future research, emphasizing best practices and optimal nanoparticles for biofilm prevention and eradication. Additionally, it underscores the potential of nanoparticles as substitutes for traditional antibiotics in healthcare and combating antibiotic resistance. A systematic literature search, encompassing Web of Science, PubMed, and Google Scholar from 2015 to 2023, yielded 48 publications meeting the review criteria. These studies employed diverse methods to explore the antibacterial activity of nanoparticles against biofilmforming bacteria strains. The implications of this study are profound, offering prospects for novel antimicrobial agents targeting biofilm-forming bacteria, often resistant to conventional antibiotics. In conclusion, nanoparticles present a promising frontier in countering biofilm-forming bacteria. This review delivers a structured analysis of current research, providing insights into the potential and challenges of nanoparticle utilization against biofilm-related challenges. While nanoparticles exhibit inherent antimicrobial properties with applications spanning healthcare, agriculture, and industries, the review acknowledges limitations such as the narrow scope of tested nanoparticles and the imperative need for extensive research on long-term toxicity and environmental impacts.

Self-Healing Conductive Hydrogels with Dynamic Dual Network Structure Accelerate Infected Wound Healing via Photothermal Antimicrobial and Regulating Inflammatory Response.

Wound infections are an escalating clinical challenge with continuous inflammatory response and the threat of drug-resistant bacteria. Herein, a series of self-healing conductive hydrogels were designed based on carboxymethyl chitosan/oxidized sodium alginate/polymerized gallic acid/Fe3+ (CMC/OSA/pGA/Fe3+, COGFe) for promoting infected wound healing. The Schiff base and catechol-Fe3+ chelation in the dynamical dual network structure of the hydrogels endowed dressings with good toughness, conductivity, adhesion, and self-healing properties, thus flexibly adapting to the deformation of skin wounds. In terms of ultraviolet (UV) resistance and scavenging of reactive oxygen species (ROS), the hydrogels significantly reduced oxidative stress at the wound site. Additionally, the hydrogels with photothermal therapy (PTT) achieved a 95% bactericidal rate in 5 min of near-infrared (NIR) light radiation by disrupting the bacterial cell membrane structure through elevated temperature. Meanwhile, the inherent antimicrobial properties of GA could reduce healthy tissue damage caused by excessive heat. The composite hydrogels could effectively promote the proliferation and migration of fibroblasts and possess good biocompatibility and hemostatic effect. In full-thickness infected wound repair experiments in rats, the COGFe5 hydrogel combined with NIR effectively killed bacteria, modulated macrophage polarization (M1 to M2 phenotype) to improve the immune microenvironment of the wound, and shortened the repair time by accelerating the expression of collagen deposition (TGF-β) and vascular factors (CD31). This combined therapy might provide a prospective strategy for infectious wound treatment.

Enhancing Presurgical Infant Orthopedic Appliances: Characterization, Mechanics, and Biofilm Inhibition of a Novel Chlorhexidine-Halloysite Nanotube-Modified PMMA.

This in vitro study aimed to develop a novel nanocomposite acrylic resin with inherent antimicrobial properties. This study evaluated its effectiveness against microbial biofilm formation, while also assessing its physical and mechanical properties. Polymethylmethacrylate (PMMA) was modified with four different concentrations of chlorhexidine halloysite nanotubes (CHX-HNTs): 1%, 1.5%, 3%, and 4.5 wt.% by weight, along with a control group (0 wt.% CHX-HNTs). The biofilm inhibition ability of the modified CHX-HNTs acrylic against Candida albicans, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus agalactiae was assessed using microtiter biofilm test. In addition, ten samples from each group were then tested for flexural strength, surface roughness, and hardness. Statistical analysis was performed using one-way ANOVA and Tukey's test for comparison (P < 0.05). CHX-HNTs effectively reduced the adhesion of Candida albicans and bacteria to the PMMA in a dose-dependent manner. The higher the concentration of CHX-HNTs, the greater the reduction in microbial adhesion, with the highest concentration (4.5 wt.%) showing the most significant effect with inhibition rates ≥98%. The addition of CHX-HNTs at any tested concentration (1%, 1.5%, 3%, and 4.5 wt.%) did not cause any statistically significant difference in the flexural strength, surface roughness, or hardness of the PMMA compared to the control group. The novel integration of CHX-HNT fillers shows promising results as an effective biofilm inhibitor on acrylic appliances. This new approach has the potential to successfully control infectious diseases without negatively affecting the mechanical properties of the acrylic resin. Clinical Relevance. The integration of CHX-HNTs into presurgical infant orthopedic appliances should be thoroughly assessed as a promising preventive measure to mitigate microbial infections. This evaluation holds significant potential for controlling infectious diseases among infants with cleft lip and palate, thereby offering a valuable contribution to their overall well-being.

Engineering Nitric Oxide-Releasing Antimicrobial Dental Coating for Targeted Gingival Therapy.

Bacterial biofilms play a central role in the development and progression of periodontitis, a chronic inflammatory condition that affects the oral cavity. One solution to current treatment constraints is using nitric oxide (NO)─with inherent antimicrobial properties. In this study, an antimicrobial coating is developed from the NO donor S-nitroso-N-acetylpenicillamine (SNAP) embedded within polyethylene glycol (PEG) to prevent periodontitis. The SNAP-PEG coating design enabled a controlled NO release, achieving tunable NO levels for more than 24 h. Testing the SNAP-PEG composite on dental floss showed its effectiveness as a uniform and bioactive coating. The coating exhibited antibacterial properties against Streptococcus mutans and Escherichia coli, with inhibition zones measuring up to 7.50 ± 0.28 and 14.80 ± 0.46 mm2, respectively. Furthermore, SNAP-PEG coating materials were found to be stable when stored at room temperature, with 93.65% of SNAP remaining after 28 d. The coatings were biocompatible against HGF and hFOB 1.19 cells through a 24 h controlled release study. This study presents a facile method to utilize controlled NO release with dental antimicrobial coatings comprising SNAP-PEG. This coating can be easily applied to various substrates, providing a user-friendly approach for targeted self-care in managing gingival infections associated with periodontitis.

Advancements in Regenerative Hydrogels in Skin Wound Treatment: A Comprehensive Review.

This state-of-the-art review explores the emerging field of regenerative hydrogels and their profound impact on the treatment of skin wounds. Regenerative hydrogels, composed mainly of water-absorbing polymers, have garnered attention in wound healing, particularly for skin wounds. Their unique properties make them well suited for tissue regeneration. Notable benefits include excellent water retention, creating a crucially moist wound environment for optimal healing, and facilitating cell migration, and proliferation. Biocompatibility is a key feature, minimizing adverse reactions and promoting the natural healing process. Acting as a supportive scaffold for cell growth, hydrogels mimic the extracellular matrix, aiding the attachment and proliferation of cells like fibroblasts and keratinocytes. Engineered for controlled drug release, hydrogels enhance wound healing by promoting angiogenesis, reducing inflammation, and preventing infection. The demonstrated acceleration of the wound healing process, particularly beneficial for chronic or impaired healing wounds, adds to their appeal. Easy application and conformity to various wound shapes make hydrogels practical, including in irregular or challenging areas. Scar minimization through tissue regeneration is crucial, especially in cosmetic and functional regions. Hydrogels contribute to pain management by creating a protective barrier, reducing friction, and fostering a soothing environment. Some hydrogels, with inherent antimicrobial properties, aid in infection prevention, which is a crucial aspect of successful wound healing. Their flexibility and ability to conform to wound contours ensure optimal tissue contact, enhancing overall treatment effectiveness. In summary, regenerative hydrogels present a promising approach for improving skin wound healing outcomes across diverse clinical scenarios. This review provides a comprehensive analysis of the benefits, mechanisms, and challenges associated with the use of regenerative hydrogels in the treatment of skin wounds. In this review, the authors likely delve into the application of rational design principles to enhance the efficacy and performance of hydrogels in promoting wound healing. Through an exploration of various methodologies and approaches, this paper is poised to highlight how these principles have been instrumental in refining the design of hydrogels, potentially revolutionizing their therapeutic potential in addressing skin wounds. By synthesizing current knowledge and highlighting potential avenues for future research, this review aims to contribute to the advancement of regenerative medicine and ultimately improve clinical outcomes for patients with skin wounds.

Nonleaching Biocidal N-Halamine-Functionalized Polyamine-, Guanidine-, and Hydantoin-Based Coatings.

Fibrous materials with inherent antimicrobial properties can help in real-time deactivation of microorganisms, enabling multiple uses while reducing secondary infections. Coatings with antiviral polymers enhance the surface functionality for existing and potential future pandemics. Herein, we demonstrated a straightforward route toward biocidal surface creation using polymers with nucleophilic biguanide, guanidine, and hydantoin groups that are covalently attached onto a solid support. Biocidal poly(N-vinylguanidine) (PVG) and poly(allylamine-co-4-aminopyridine-co-5-(4-hydroxybenzylidene)hydantoin) (PAH) were introduced for coating applications along with commercially available polyvinylamine (PVAm) and poly(hexamethylene biguanide) (PHMB). Nonleaching coatings were created by first fabricating bifunctional siloxane or isocyanate precursor coatings on the cotton, nylon-cotton, and glass fiber fabric, followed by the polymer attachment. The developed grafting methods ensured the stability of the coating and the reuse of the material while maintaining the biocidal properties. Halogenation of polymer-coated fabric was conducted by aqueous solutions of sodium hypochlorite or in situ generation of hypobromous acid (HOBr), resulting in surfaces coated by N-halamines with high contents of active > N-Cl or > N-Br groups. The polymer-coated fabrics were stable in multiple laundry cycles and maintained hydrophilic character after coating and halogenation. Halogenated polymer-coated fabrics completely inactivated human respiratory coronavirus based on a contact-killing mechanism and were shown to be reusable after recharging with bromine or chlorine.

Functionalization of sterculia gum for making platform hydrogels via network formation for use in drug delivery

Recently, various advancements have been made in the development of functional polymeric materials for innovative applications. Herein this work, functionalization of sterculia gum (SG) was carried out via grafting of poly(2-(methacryloyloxy) ethyltrimethylammonium chloride) (METAC)-polyvinyl pyrrolidone (PVP) to develop hydrogel dressings as a platform for use in drug delivery (DD). The innovation of the present work is the exploration of inherent antioxidant and antimicrobial properties of the SG along with antimicrobial characteristic of poly(METAC) and PVP, to design the doxycycline encapsulated hydrogel dressings for better wound healing. FESEM, EDS and AFM analyzed the surface morphology of hydrogels. FTIR, 13C NMR and XRD inferred inclusion of poly(METAC)-PVP into polymers. 13C NMR confirmed the incorporation of poly(METAC) and PVP onto gum by the presence of a peak at 54.74 ppm because of methyl carbon attached to quaternary nitrogen of poly(METAC) and at 45.48 ppm due to the ring carbon of PVP along with FTIR peak at 949 cm−1 because of CN bending of quaternary nitrogen of poy (METAC). Thermal characterization of copolymers has been performed using TGA analysis. One gram of copolymeric hydrogel dressing absorbed 6.51 ± 0.03 g simulated salivary fluid (SSF) and 7.65 ± 0.03 g simulated wound fluid (SWF). Release of doxycycline drug occurred in a sustained manner and followed the Non-Fickian diffusion mechanism from hydrogels. The release profile was most effectively described by Hixon-Crowell kinetic model. Hydrogel demonstrated biocompatibility and expressed thrombogenicity 79.7 ± 4.9 % during its polymer-blood interactions. Copolymer revealed mucoadhesive property, requiring a force of 77.00 ± 0.01 mN to detach from bio-membrane. Additionally, it exhibited antioxidant features, showing 43.81 ± 0.286 % free radical scavenging. Hydrogel dressings were mechanically stable and revealed 0.76 ± 0.09 N mm−2 tensile strength and 9.18 ± 0.01 N burst strength. Polymer films were permeable to oxygen and water vapor and were impermeable to microorganisms. Hydrogel dressings exhibited antimicrobial properties against Pseudomonas aeruginosa and Staphylococcus aureus bacteria. Overall, these properties displayed the suitability of hydrogels for wound dressing (WD) applications which may actively enhance wound healing.

Surface functionalization of 3D printed poly-ε-caprolactone by ultrashort laser mirostructuring and ZnO nanolayer deposition

Due to its mechanical properties and good biocompatibility, polycaprolactone (PCL) is a promising material for bone tissue regeneration. However, a major limitation to its use remains the lack of inherent antimicrobial properties and its susceptibility to bacterial colonisation and biofilm formation. A potent strategy for overcoming such issues is surface functionalisation at micro and nano level, which can have a great impact on cell-surface interaction without affecting the integrity of the material. This study presents a novel methodology for surface modification of polymers combining ultrashort laser microstructuring and atomic layer deposition of ZnO. For this purpose, the surface of 3D printed PCL scaffolds was treated with a femtosecond laser (λ=800 nm; τ=75 fs) in order to develop parallel microchannels onto which ZnO nanolayers were further deposited. The presence of ZnO on the laser structured and unstructured scaffolds was detected by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). Both methods confirmed the successful layering as EDX further highlighted a trend that ZnO built up substantially more at the bottom of the microchannels rather than at the top of them. The obtained results would allow proceeding to the next step of the study – investigating the antimicrobial effect of the developed interfaces.

Gallic acid-doped multifunctional hybrid hydrogel for antioxidant and antibacterial studies

The design and fabrication of multifunctional hybrid hydrogels for various biomedical applications have sparked tremendous scientific interest and still remain a formidable challenge. Here, we report the construction of a multifunctional supramolecular hybrid hydrogel through a facile preparation route by co-assembling the L-phenylalanine-derivative (LPF) gelator with agarose (AG) and gallic acid (GA). The experimental analysis demonstrates that the components of hybrid hydrogel co-assembled to form a cross-linked interpenetrating network that is mainly formed through non-covalent interactions, thereby resulting in remarkable enhancement in rheological properties with an elastic modulus (G′) of 12715 Pa. Due to the inherent antimicrobial property of GA, this hybrid hydrogel exhibited antibacterial activities against both Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial cells. Furthermore, the presence of GA enabled hybrid hydrogels to offer efficient antioxidant properties by scavenging free radicals such as DPPH· and ABTS·+. The cell adhesion, proliferation, and spreading behavior of L929 cells were significantly improved on the hybrid hydrogel substrate. These experimental findings suggest that this high-performance hybrid hydrogel possessing antibacterial, antioxidant, and biocompatible properties, opens new avenues for extensive applications in the biomedical field.

Sustainable yarns and fabrics from tri-blends of banana, cotton and tencel fibres for textile applications

Millions of tons of banana pseudo-stem are readily available annually, making it a sustainable resource for banana fiber. Banana fibres possess inherent mechanical strength and anti-microbial properties, accompanied by stiffness and a harsh feel that undermine their full utilization in textiles. An effort was made in this study to create eco-friendly yarns and fabrics by combining banana fiber reclaimed from banana agro-waste with cotton and regenerated cellulosic (Tencel) fiber in varying blend ratios. The negative influence attached to banana fibre due to its chemical softening was overcome by boiling it in distilled water. The softened banana fibres were evaluated based on feel, strength, and weight loss. Three blend ratios, i.e., 10%, 20%, and 30% of banana fibre by weight, were selected to produce Banana: Cotton: Tencel blended yarns. Yarn characterizations revealed excellent mechanical properties as compared to the benchmark Cotton: Tencel 50:50 yarns. The yarn bundle strength and single yarn strength obtained in the case of 20% banana fibre blended yarn were approximately 11% and 8.62% higher than the Cotton: Tencel 50:50 blended yarns and 22.90% better in the yarn quality index analysis, respectively. Fabrics were formed using the said yarns on an industrial loom. Banana fibre blended fabrics exhibited a 6.61% higher tear strength, 18.8% more air permeability, 20% more elongation, and 12% higher tensile strength as compared to the Cotton: Tencel blended fabrics. The provided findings in this study propose that following this design approach during textile manufacturing will lead to more environmental and economic gains with high performance.

Bactericidal and Fungicidal Action of Copper Nanoparticles on Leather Surface

Although tanning makes the collagen matrix resilient against microbial attack, the chemicals used in the finishing process are susceptible to microbes. Hence, it is imperative to develop a finishing process with inherent antimicrobial properties. Leathers with antimicrobial properties evoke a considerable array of interest in consumers. The present study aims to enhance the antimicrobial properties of the leather using copper nanoparticles in the finishing and retanning process. Copper nanoparticles have been synthesized by chemical reduction using copper sulphate pentahydrate as the precursor with dialdehyde starch and gallic acid. The prepared nanoparticles have been characterized using UV-Visible spectrometry, dynamic light scattering, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction techniques. The prepared nanoparticles have been used in both retanning and finishing processes. The experimental leather retanned using copper nanoparticles possess good mechanical strength properties and color index value compare to the control. Nanoparticles are effective against both gram negative and positive bacterial organisms. The nanoparticles also inhibit the growth of common fungus, which can colonize on leather. Thus, the current study paves the way for a novel solution that is an alternative to biocides and antimicrobial chemicals and is more effective in inhibiting microbial growth.

Study on the performance and application of coatings based on chitosan/gelatin/microbeads composite aerogel

AbstractPlastic reduction regulations have resulted in the gradual replacement of traditional food plastic packaging materials with biodegradable and recyclable paper‐based ones. However, paper is prone to water absorption and moisture damage, and it has poor insulation properties, which can impact food quality and user experience. Recently, biopolymers have gained wide interest as the main substrate for paper coatings, providing various qualities for paper‐based materials to meet food packaging requirements. The coating based on chitosan/gelatin/microbeads composite aerogel prepared in this study not only possesses inherent antimicrobial and preservation properties but also enhances the cardboard's mechanical strength, hydrophobicity, and thermal insulation effect after coating on cardboard. When the coating thickness was 30 μm, the tensile strength of the cardboard was enhanced by 0.65 kN/m, the contact angle increased by 19.3°, and the thermal conductivity coefficient decreased by 0.024 W·m−1·K−1. Therefore, the biopolymer composite coating developed in this study provides an eco‐friendly substitute for plastic coatings on cardboard. In addition to bacteriostatic and preserving freshness, it can also address paper‐based material shortcomings, ensuring food quality and safety with comprehensive packaging protection.

A Review of Textile Fabrication Using Bioactive Compounds Derived from Natural Products

Antimicrobial-treated textiles should exhibit efficacy against a broad spectrum of bacterial and fungal species, all while maintaining user safety with a non-toxic profile. Natural antimicrobial compounds play a vital role in textile finishing processes. The proliferation of synthetic antimicrobial agents introduces environmental and consumer safety concerns. Given these potential hazards associated with synthetic agents, the utilization of natural antimicrobial agents is gaining traction, as they tend to have fewer adverse effects on users and are more environmentally sustainable. Numerous natural antimicrobial compounds, sourced from plants such as neem, basil, turmeric, aloe vera, and clove oil, have been developed, showcasing inherent antimicrobial properties. This review article highlights the importance of incorporating bioactive components in the creation of antibacterial textile fabrics.

Polyphenolic natural products as photosensitizers for antimicrobial photodynamic therapy: recent advances and future prospects.

Antimicrobial photodynamic therapy (aPDT) has become a potent contender in the fight against microbial infections, especially in the context of the rising antibiotic resistance crisis. Recently, there has been significant interest in polyphenolic natural products as potential photosensitizers (PSs) in aPDT, given their unique chemical structures and inherent antimicrobial properties. Polyphenolic natural products, abundant and readily obtainable from natural sources, are generally regarded as safe and highly compatible with the human body. This comprehensive review focuses on the latest developments and future implications of using natural polyphenols as PSs in aPDT. Paramount polyphenolic compounds, including curcumin, hypericin, quercetin, hypocrellin, celastrol, riboflavin, resveratrol, gallic acid, and aloe emodin, are elaborated upon with respect to their structural characteristics, absorption properties, and antimicrobial effects. Furthermore, the aPDT mechanism, specifically its targeted action on microbial cells and biofilms, is also discussed. Polyphenolic natural products demonstrate immense potential as PSs in aPDT, representing a promising alternate approach to counteract antibiotic-resistant bacteria and biofilm-related infections.

Superior antibacterial properties of copper-doped titanium oxide films prepared by micro-arc oxidation

To prevent bacterial contamination and enhance wear-resistance of titanium-based tools and implants, it is crucial to develop functional coatings with inherent antimicrobial property and high surface hardness. In this study, the micro-arc oxidation technique was employed to prepare ceramic oxide films with antibacterial properties on titanium metal surfaces by incorporating trace amounts of copper. It was found that the phytic acid (C6H18O24P6) used as the chelating agent in the Cu-containing electrolyte can not be recycled and the adding of alternative chelating agent calcium gluconate (C12H22O14Ca) can significantly promote the cyclic utilization. The oxide film prepared by using C12H22O14Ca as the chelating agent exhibits a typical volcanic micro-arc oxidation morphology with uniform copper distribution, high hardness and excellent substrate adhesion. Most importantly, in vitro antibacterial tests demonstrate the outstanding antibacterial performance of Cu-doped TiO2 film with an antibacterial rate of up to 99.9% against Escherichia coli and Staphylococcus aureus.

Looking for Novel Natural Gels to Improve Cleaning Methods for Bronze Leachates on Marble.

Marble is one of the materials most susceptible to copper leaching, resulting in easily identifiable turquoise stains on the marble. This problem is particularly relevant when we are talking about marble structures of heritage value. For this reason, conservators look for cleaning materials that are specific to the structure to be treated without damaging the original surface. Materials such as agar have been studied for a long time. Agar creates a controlled water release system that adapts to the needs of conservators who seek the greatest possible cleanliness without damaging the material to be treated. To improve the cleaning, chelating agents such as EDTA are added to the agar composition. However, the microbiological growth and the damage it produces to the original material are disadvantages to take into account. In order to solve these problems, other natural materials with cleaning potential such as kudzu and konjac gels were studied in combination with other chelating agents such as citrate, oxalate, and gluconic acid. For the characterization and evaluation of copper cleaning, various analytical techniques were used, including Raman spectroscopy, colorimetry, X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS). In this study, both konjac and kudzu emerged as promising alternatives to agar, revealing distinctive features such as simplified preparation methods and inherent antimicrobial properties. The EDTA chelator was found to be the most harmful for marble surfaces, as it extracted a greater amount of calcium from the marble during application of the gels doped with it. Citrate and gluconic acid have been identified as a promising substitute to prepare doped gels for the removal of copper stains. These compounds exhibit comparable or potentially superior cleaning capabilities than EDTA, with no negative side effects.

Spices as Sustainable Food Preservatives: A Comprehensive Review of Their Antimicrobial Potential.

Throughout history, spices have been employed for their pharmaceutical attributes and as a culinary enhancement. The food industry widely employs artificial preservatives to retard the deterioration induced by microbial proliferation, enzymatic processes, and oxidative reactions. Nevertheless, the utilization of these synthetic preservatives in food products has given rise to significant apprehension among consumers, primarily stemming from the potential health risks that they pose. These risks encompass a spectrum of adverse effects, including but not limited to gastrointestinal disorders, the disruption of gut microbiota, allergic reactions, respiratory complications, and concerns regarding their carcinogenic properties. Consequently, consumers are displaying an increasing reluctance to purchase preserved food items that contain such additives. Spices, known for their antimicrobial value, are investigated for their potential as food preservatives. The review assesses 25 spice types for their inherent antimicrobial properties and their applicability in inhibiting various foodborne microorganisms and suggests further future investigations regarding their use as possible natural food preservatives that could offer safer, more sustainable methods for extending shelf life. Future research should delve deeper into the use of natural antimicrobials, such as spices, to not only replace synthetic preservatives but also optimize their application in food safety and shelf-life extension. Moreover, there is a need for continuous innovation in encapsulation technologies for antimicrobial agents. Developing cost-effective and efficient methods, along with scaling up production processes, will be crucial to competing with traditional antimicrobial options in terms of both efficacy and affordability.

Enhanced osteogenesis and bactericidal performance with additively manufactured MgO and Cu-added CpTi for load-bearing implants.

Titanium, being the ultimate choice of metallic material for implant applications, its bio-inertness causes delayed bone-tissue integration at the implant site and prevents expedited healing for the patient. This can cause a severe issue for patients with immunocompromised bone health. Infections at the implant site are another concern; titanium does not offer inherent antimicrobial properties. Current strategies addressing the issues above include using cemented implants as a coating on Ti6Al4V bulk material for orthopedic applications. Roadblock arises with coating failure due to weak interfacial bond at the Ti-cement interface, resulting in revision surgeries. We have added osteogenic MgO and antibacterial Cu to CpTi and processed them using metal additive manufacturing (AM) to address these issues. Mg, an essential trace element in the body, has been proven to enhance osseointegration in vivo. Cu has been popular for its bactericidal capabilities. With 1 wt.% of MgO addition in the CpTi matrix, we have observed a four-fold increase in the mineralized bone formation at the bone-implant interface in vivo. The presence of 3 wt.% of Cu showed no cytotoxicity markers, and adding Cu to CpTi-MgO chemical makeup showed similar in vivo performance to CpTi-MgO. In vitro bacterial studies with gram-positive Staphylococcus aureus bacteria showed 81% bacterial efficiency displayed by CpTi-MgO-Cu at the end of 72 h of culture. Our findings highlight the synergistic benefits of CpTi-MgO-Cu, which exhibit superior early-stage osseointegration and antimicrobial capabilities.

Designing nanohesives for rapid, universal, and robust hydrogel adhesion

Nanoparticles-based glues have recently been shown with substantial potential for hydrogel adhesion. Nevertheless, the transformative advance in hydrogel-based application places great challenges on the rapidity, robustness, and universality of achieving hydrogel adhesion, which are rarely accommodated by existing nanoparticles-based glues. Herein, we design a type of nanohesives based on the modulation of hydrogel mechanics and the surface chemical activation of nanoparticles. The nanohesives can form robust hydrogel adhesion in seconds, to the surface of arbitrary engineering solids and biological tissues without any surface pre-treatments. A representative application of hydrogel machine demonstrates the tough and compliant adhesion between dynamic tissues and sensors via nanohesives, guaranteeing accurate and stable blood flow monitoring in vivo. Combined with their biocompatibility and inherent antimicrobial properties, the nanohesives provide a promising strategy in the field of hydrogel based engineering.