Antimicrobial characteristics and biocompatibility of the surgical sutures coated with biosynthesized silver nanoparticles

Clinical Grade Fibroin Sutures with Bioactive Gold Clusters Enhance Surgical Wound Healing via Inflammation Modulation

Silk sutures are common in surgeries, and silk-based textiles are widely used in clinical medicine on account of their great mechanical properties and biodegradability. However, due to the lack of biocatalytic activity, silk sutures show unsatisfactory anti-inflammatory properties and healing speed. To address this constraint, we construct clinical grade bioactive gold cluster-sutures through a heterojunction. The antioxidant activity of bioactive gold cluster-sutures is ∼160 times more than that of clinical sutures. Meanwhile, the suture displays superb reactive oxygen species (ROS) scavenging, superoxide dismutase-like (SOD-like, 5 times more than the silk suture), and catalase-like (CAT-like) activities. The clusters assemble on the surface of silk through hydrogen bonding, leading to a durable catalytic and structural stability for 15 months without decay. Subsequently, the suture significantly accelerates wound healing by exerting excellent anti-inflammatory effects, improving neovascularization and collagen deposition. Clinical grade bioactive gold clusters with high bioactivity, stability, and biocompatibility hold promise for clinical translation and pave the way for other implanted biomaterials from wound healing to intelligent textiles.

Biomaterials with antifungal strategies to fight oral infections

Oral fungal infections pose a threat to human health and increase the economic burden of oral diseases by prolonging and complicating treatment. A cost-effective strategy is to try to prevent these infections from happening in the first place. With this purpose, biomaterials with antifungal properties are a crucial element to overcome fungal infections in the oral cavity. In this review, we go through different kinds of biomaterials and coatings that can be used to functionalize them. We also review their potential as a therapeutic approach in addition to prophylaxis, by going through traditional and alternative antifungal compounds, e.g., essential oils, that could be incorporated in them, to enhance their efficacy against fungal pathogens. We aim to highlight the potential of these technologies and propose questions that need to be addressed in prospective research. Finally, we intend to concatenate the key aspects and technologies on the use of biomaterials in oral health, to create an easy to find summary of the current state-of-the-art for researchers in the field.

Nonabsorbable Barbed Sutures for Diastasis Recti. A Useful Device with Unexpected Risk: Two Case Reports

The introduction of nonabsorbable barbed sutures in plastic surgery has allowed the achievement of significant results in terms of efficacy and short- and long-term outcomes. However, a nonabsorbable material with no antibacterial coating could act as a substrate for subclinical bacterial colonization and thereby determine recurrent subacute and chronic infective-inflammatory processes. The authors report a clinical experience of subacute infectious complications after two cases of diastasis recti surgical correction. The authors present a two-case series in which a nonabsorbable barbed suture was used for the repair of diastasis recti. The postoperative course was complicated by surgical site infection. The origin of the infectious process was clearly localized in the fascial suture used for diastasis correction. The suture was colonized by bacteria resulting in the formation of multiple granulomas of the abdominal wall a few months postoperatively. In both the reported cases, the patients partially responded to the antibiotic targeted therapy and reoperation was required. The microbiological analyses confirmed the colonization of sutures by Staphylococcus aureus . Barbed nonabsorbable sutures should be avoided for diastasis recti surgical correction to minimize the risk of infectious suture-related complications. The paper's main novel aspect is that this is the first clinical report describing infectious complications after surgical correction of diastasis recti with barbed polypropylene sutures. The risk of microbiological subclinical colonization of polypropylene suture untreated with antibacterial coating, therefore, should be taken into account.

MoO3-X nanodots coated suture for combating surgical site infection via antibacterial and anti-inflammatory properties

Surgical site infection (SSI) significantly affects patient recovery time, health outcomes and quality of life which is closely associated with the use of implants or mesh. Sutures are the most frequently used implants that play a significant role in the development of SSI. Studies have demonstrated that the administration of effective bactericidal and anti-inflammatory treatments can significantly decrease the incidence of SSI. To address this concern, a versatile suture was engineered by coating MoO3-X nanodots in this study. The incorporation of MoO3-X nanodots endowed the suture with desirable antibacterial and anti-inflammatory properties that were evaluated in in vitro and in vivo experiments. The results showed its remarkable ability to facilitate wound healing and prevent SSI through its dual action of combating bacterial infection and reducing inflammation. These findings highlight the promising potential of this multifunctional surgical suture as a versatile tool to promote better outcomes in surgical procedures.

Peptide-AIE Nanofibers Functionalized Sutures with Antimicrobial Activity and Subcutaneous Traceability

As one of the most widely used medical devices, sutures face challenges related to surgical site infections (SSIs) and lack of subcutaneous traceability. In the present study, a facile and effective approach using peptide-AIE nanofibers (NFs-K18) to create fluorescent-traceable antimicrobial sutures, which have been applied to four commercially available sutures is developed. The functionalized sutures of PGAS-NFs-K18 and PGLAS-NFs-K18 exhibit fluorescence with excellent penetration from 4 mm chicken breasts. They also demonstrate remarkable stability after 24 h of white light illumination and threading through chicken breasts 10 times. These sutures efficiently generate ROS, resulting in significant suppression of four clinical bacteria, with the highest antimicrobial rate of ≈100%. Moreover, the sutures exhibit favorable hemocompatibility and biocompatibility. In vivo experiments demonstrate that the optimized PGLAS-NFs-K18 suture displays potent antimicrobial activity against MRSA, effectively inhibiting inflammation and promoting tissue healing in both skin wound and abdominal wall wound models, outperforming the commercially available Coated VICRYL Plus Antibacterial suture. Importantly, PGLAS-NFs-K18 exhibits sensitive subcutaneous traceability, allowing for accurate in situ monitoring of its degradation. It is believed that this straightforward strategy offers a new pathway for inhibiting SSIs and monitoring the status of sutures.

In-situ biosynthesized plant exudate gums‑silver nanocomposites as corrosion inhibitors for mild steel in hydrochloric acid medium

Natural gums due to availability, multifunctionality, and nontoxicity are multifaceted in application. In corrosion inhibition applications, their performance, in unmodified form is unsatisfactory because of high hydration rate, solubility issues, algal and microbial contamination, as well as thermal instability. This work attempts to enhance the inhibitive performance of Berlinia grandiflora (BEG) and cashew (CEG) exudate gums through various modification approaches. The potential of biogenic BEG and CEG gums-silver (Ag) nanocomposites (NCPs) for corrosion inhibition of mild steel in 1 M HCl is studied. The nanocomposites were characterized using the FTIR, UV-vis, and TEM techniques. The corrosion studies through the gravimetric and electrochemical (PDP, EIS, LPR, and EFM) analyses reveal moderate inhibition performance by the nanocomposites. Furthermore, the PDP results reveal that both inhibitors are mixed-type with maximum corrosion inhibition efficiencies (IEs) of 61.2 % and 54.2 % for BEG-Ag NCP and CEG-Ag NCP, respectively at an optimum concentration of 1.0 %. Modification of these inhibitors with iodide ion (KI) significantly increased the IE values to 90.1 % and 88.5 % for BEG-Ag NCP and CEG-Ag NCP at the same concentration. Surface observation of the uninhibited and inhibited steel samples using SEM/EDAX, 3D Surface profilometer, and AFM affirm that the modified nanocomposites are highly effective.

Fabrication of a Biocompatible Nanoantimicrobial Suture for Rapid Wound Healing after Surgery

Suture-associated infections on surgical sites are known to be related to the surface characteristics of the sutures. The present study aimed to fabricate a novel functional suture for surgical procedures and characterize its antioxidative, antimicrobial, and in vitro wound healing properties. St John's wort, Hypericum perforatum, extract (eHp), and biogenic silver nanoparticles (AgNPs) have been combined and used for coating the silk sutures. Antioxidant, antimicrobial capacity, and in vitro wound healing potential of the coated sutures have been examined. The morphological and microanalytical examination of the coated sutures was also performed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). According to the antioxidant activity tests, free radical scavenging and β-carotene linoleic acid tests revealed that the antioxidative potential of H. perforatum extract-AgNP combination (eHp-AgNP) at 10 mg/mL concentration was higher than those of positive controls, ascorbic acid and α-tocopherol. Coating the sutures with eHp-AgNP resulted in a remarkable inhibition activity of the sutures against Staphylococcus aureus, which is a pathogenic member of human microbiota. When compared with the control groups, it was investigated that coating the sutures with eHp-AgNP stimulated the cell migration of the fibroblasts to heal the artificial wound. Due to their beneficial effects, the eHp-AgNP-coated silk sutures might be a potential antibacterial and wound healing accelerator for surgical approaches.

Preventing Staphylococci Surgical Site Infections with a Nitric Oxide-Releasing Poly(lactic acid-co-glycolic acid) Suture Material

Of the 27 million surgeries performed in the United States each year, a reported 2.6% result in a surgical site infection (SSI), and Staphylococci species are commonly the culprit. Alternative therapies, such as nitric oxide (NO)-releasing biomaterials, are being developed to address this issue. NO is a potent antimicrobial agent with several modes of action, including oxidative and nitrosative damage, disruption of bacterial membranes, and dispersion of biofilms. For targeted antibacterial effects, NO is delivered by exogenous donor molecules, like S-nitroso-N-acetylpenicillamine (SNAP). Herein, the impregnation of SNAP into poly(lactic-co-glycolic acid) (PLGA) for SSI prevention is reported for the first time. The NO-releasing PLGA copolymer is fabricated and characterized by donor molecule loading, leaching, and the amount remaining after ethylene oxide sterilization. The swelling ratio, water uptake, static water contact angle, and tensile strength are also investigated. Furthermore, its cytocompatibility is tested against 3T3 mouse fibroblast cells, and its antimicrobial efficacy is assessed against multiple Staphylococci strains. Overall, the NO-releasing PLGA copolymer holds promise as a suture material for eradicating surgical site infections caused by Staphylococci strains. SNAP impregnation affords robust antibacterial properties while maintaining the cytocompatibility and mechanical integrity.

Multi-functional copper oxide nanoparticles synthesized using Lagerstroemia indica leaf extracts and their applications

Developing multifunctional nanomaterials through environmentally friendly and efficient approaches is a pivotal focus in nanotechnology. This study aimed to employ a biogenic method to synthesize multifunctional copper oxide nanoparticles (LI-CuO NPs) with diverse capabilities, including antibacterial, antioxidant, and seed priming properties, as well as photocatalytic organic dye degradation and wastewater treatment potentials using Lagerstroemia indica leaf extract. The synthesized LI-CuO NPs were extensively characterized using UV-vis spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). The colloid displayed surface plasmon resonance peaks at 320 nm, characteristic of LI-CuO NPs. DLS analysis revealed an average particle size of 93.5 nm and a negative zeta potential of -20.3 mV. FTIR and XPS analyses demonstrated that LI-CuO NPs possessed abundant functional groups that acted as stabilizing agents. XRD analysis indicated pure crystalline and spherical LI-CuO NPs measuring 36 nm in size. Antibacterial tests exhibited significant differential activity of LI-CuO NPs against both gram-negative (Escherichia coli, Salmonella typhimurium) and gram-positive (Staphylococcus aureus and Listeria monocytogenes) bacteria. In antioxidant tests, the LI-CuO NPs demonstrated a remarkable radical scavenging activity of 97.6 % at a concentration of 400 μg mL-1. These nanoparticles were also found to enhance mustard seed germination at low concentrations. With a remarkable reusability, LI-CuO NPs exhibited excellent photocatalytic performance, with a degradation efficiency of 97.6 % at 150 μg/mL as well as a 95.6 % reduction in turbidity when applied to wastewater treatment. In conclusion, this study presents environmentally friendly method for the facile synthesis of LI-CuO NPs that could potentially offer promising applications in biomedicine, agriculture, and environmental remediation due to their multifunctional properties.

Biogenic synthesis, characterization, and in vitro biological investigation of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata

The current research aimed to study the green synthesis of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata (RC) aqueous extract as a potent reducing and stabilizing agent. The obtained RC-AgONPs were characterized using UV, FT-IR, XRD, DLS, SEM, and EDX to investigate the morphology, size, and elemental composition. The size of the RC-AgONPs was found to be ~ 21.66 nm and an almost uniform distribution was executed by XRD analysis. In vitro studies were performed to reveal biological potential. The AgONPs exhibited efficient DPPH free radical scavenging potential (71.3%), reducing power (63.8 ± 1.77%), and total antioxidant capacity (88.5 ± 4.8%) to estimate their antioxidative power. Antibacterial and antifungal potentials were evaluated using the disc diffusion method against various bacterial and fungal strains, and the zones of inhibition (ZOI) were determined. A brine shrimp cytotoxicity assay was conducted to measure the cytotoxicity potential (LC50: 2.26 μg/mL). In addition, biocompatibility tests were performed to evaluate the biocompatible nature of RC-AgONPs using red blood cells, HEK, and VERO cell lines (< 200 μg/mL). An alpha-amylase inhibition assay was carried out with 67.6% inhibition. Moreover, In vitro, anticancer activity was performed against Hep-2 liver cancer cell lines, and an LC50 value of 45.94 μg/mL was achieved. Overall, the present study has demonstrated that the utilization of R. capitata extract for the biosynthesis of AgONPs offers a cost-effective, eco-friendly, and forthright alternative to traditional approaches for silver nanoparticle synthesis. The RC-AgONPs obtained exhibited significant bioactive properties, positioning them as promising candidates for diverse applications in the spheres of medicine and beyond.

Study on preparation and properties of silver alloy for Mongolian medicine acupuncture

The Mongolian medical silver needles often encounter issues of bending, fracturing, and blunting in clinical applications. Similarly, Mongolian warm needles can cause burns on patients due to inaccurate temperature control. In this study, we developed an Ag85Cu15 alloy specifically for acupuncture needles based on material preparation. By incorporating appropriate amounts of Mn and Ti elements, we were able to enhance the mechanical properties and biocompatibility of the acupuncture needles. Compared to commercially available silver needles, this alloy exhibited a significant increase in microhardness up to 210.2 Hv0.2 and an improved tensile strength of 880.2 MPa. Furthermore, we designed a thermoelectric effect-based temperature measurement model for precise control of the warm needle's temperature, enhancing the therapeutic effectiveness of the treatment.

Antimicrobial and Cytotoxic Effect of Positively Charged Nanosilver-Coated Silk Sutures

Sutures are a crucial component of surgical procedures, serving to close and stabilize wound margins to promote healing. However, microbial contamination of sutures can increase the risk of surgical site infections (SSI) due to colonization by pathogens. This study aimed to tackle SSI by synthesizing positively charged silver nanoparticles (P-AgNPs) and using them to produce antimicrobial sutures. The P-AgNPs were reduced and stabilized using polyethylenimine (PEI), a cationic branched polymer. The physiochemical characteristics of P-AgNPs were confirmed from the surface plasmon resonance (SPR) peak at 419 nm, spherical morphology with a particle size range of 8-10 nm, PEI functional groups on NPs, a hydrodynamic diameter of 12.3 ± 2.4 nm, and a zeta potential of 31.3 ± 6 mV. Subsequently, the surfaces of silk sutures were impregnated with P-AgNPs at different time intervals (24, 48, and 96 h) using an ex situ method. Scanning electron microscopy (SEM) and tensile strength studies were conducted to determine the coating and durability of the NP-coated sutures. The NPs were quantified on sutures using inductively coupled plasma optical emission spectrophotometry (ICP-OES), which was in the range of 1-5 μg. Primarily, antimicrobial activity was studied using three microorganisms (Candida albicans, Streptococcus mutans, and Staphylococcus aureus) for both P-AgNPs and suture-coated P-AgNPs using the agar diffusion method. The results showed that only the NPs and NP-coated sutures exhibited enhanced antimicrobial effects against bacteria and fungi. Finally, the cytotoxicity of the sutures was investigated using stem cells from the apical papilla (SCAPs) for 24 h, which exhibited more than 75% cell viability. Overall, the results indicate that NP-coated sutures can potentially be used as antimicrobial sutures to diminish or inhibit SSI in postoperative or general surgery patients.

Fabrication of controlled-release silver nanoparticle polylactic acid microneedles with long-lasting antibacterial activity using a micro-molding solvent-casting technique

Most topical drug delivery techniques do not provide therapeutic concentrations for treatment of surgical site and other local infections and, therefore, require some kind of enhancement, such as physical methods like microneedles, the subject of the present investigation. Here, controlled-release long-lasting antibacterial polylactic acid (PLA) microneedles containing 1, 3, and 5% silver nanoparticles (AgNP) were prepared using micro-molding solvent-casting technique. Microneedles were characterized using optical microscopy, SEM, FTIR, XRD, and DSC. Also, mechanical strength, barrier disruption ability, insertion depth, in-vitro release kinetics, antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa, and silver permeation through rat skin were studied. Microneedles showed good mechanical strength with no signs of failure at an optimum PLA concentration of 25% (w/v). FTIR revealed no chemical interaction between ingredients, and XRD confirmed presence of AgNP in microneedles. Microneedles penetrated the skin model at depth of up to 1143 μm resulting 5-7 times increase in transepidermal water loss (TEWL). Release studies showed 2.2, 6.8, and 8.1 µg silver release from the whole body (obeying Higuchi's release model) and 0.33, 0.45, and 0.78 µg from the needles alone (obeying Fickian-cylindrical type release) for 1, 3, and 5% AgNP microneedles, respectively. Also, prolonged antibacterial activity (for 34 days) was observed. Skin studies over 72 h indicated that besides needles, silver is also released from the baseplate which had a marginal share in total silver permeation through the skin. In conclusion, a straightforward solvent-casting technique can be used to successfully prepare strong AgNP-containing PLA microneedles capable of long-lasting antibacterial activity.

Implementation of Silver Nanoparticles Green Synthesized with Leaf Extract of Coccinia grandis as Antimicrobial Agents Against Head and Neck Infection MDR Pathogens

BACKGROUND

Head and neck infections (HNI) associated with multidrug resistance (MDR) offer several health issues on a global scale due to inaccurate diagnosis.

OBJECTIVES

This study aimed to identify the bacteria and Candidal isolates and implement the silver nanoparticles green synthesized with leaf extract of Coccinia grandis (Cg-AgNPs) as a therapeutic approach against HNI pathogens.

METHODS

The Cg-AgNPs were characterized by the UV-visible spectrophotometer, FT-IR analysis, Zeta particle size, Zeta potential, and field emission scanning electron microscope (FESEM) analysis to validate the synthesis of nanoparticles. Additionally, the antimicrobial activity of Cg-AgNPs was presented by the zone of inhibition (ZOI), minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and antibiofilm assay. Moreover, the cell wall rupture assay was visualized on SEM for the morphological study of antimicrobial activities, and the in-vivo toxicity was performed in a swiss mice model to evaluate the impact of Cg-AgNPs on various biological parameters.

RESULTS

Different bacterial strains (Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa) and Candida sp. (Candida albicans, Candida tropicalis, Candida orthopsilosis, and Candida glabrata) were identified. The MIC, MBC, and antibiofilm potential of Cg-AgNPs were found to be highest against A. baumannii: 1.25 μg/ml, 5 μg/ml, and 85.01±5.19% respectively. However, C. albicans and C. orthopsilosis revealed 23 mm and 21 mm of ZOI. Subsequently, the micromorphology of the cell wall rupture assay confirmed the efficacy of Cg-AgNPs, and no significant alterations were seen in biochemical and hematological parameters on the swiss mice model in both acute and subacute toxicity studies.

CONCLUSION

The green synthesized Cg-AgNPs have multifunctional activities like antibacterial, anticandidal, and antibiofilm activity with no toxicity and can be introduced against the HNI pathogens.

Biogenic silver nanoparticles: in vitro activity against Staphylococcus aureus methicillin-resistant (MRSA) and multidrug-resistant coagulase-negative Staphylococcus (CoNS)

Multidrug-resistant (MDR) bacteria are one problem in health since the therapeutic alternative are reduced. For this, the application of nanotechnology through functionalized nanoparticles, like a biogenic silver nanoparticle (Bio-AgNP), obtained by biological synthesis, emerges as a possible alternative against the MDR bacteria. This study aimed to evaluate the antibacterial and antibiofilm activity of Bio-AgNP obtained for biological synthesis by Fusarium oxysporum strain 551 against methicillin-resistant Staphylococcus aureus (MRSA) and MDR coagulase-negative Staphylococcus (CoNS) isolates. Bio-AgNP has activity against S. aureus ATCC 25904, Staphylococcus epidermidis ATCC 35984, and MDR isolates, with minimal inhibitory concentration (MIC) ranging from 3.75 to 15 μg.mL-1 and minimal bactericidal concentration (MBC) from 7.5 to 30 μg.mL-1. In the membrane leakage assay, it was observed that all concentrations tested led to proteins release from the cellular content dose-dependently, where the highest concentrations led to higher protein in the supernatant. The 2×MIC of Bio-AgNP killed ATCC 35984 after 6h of treatment, and ATCC 25904 and S. aureus (SA3) strains after 24h of treatment. The 4×MIC was bactericidal in 6h of treatment for all strains in the study. The biofilm of MDR isolates was inhibited in 80.94 to 100% and eradicated in 60 to 94%. The confocal laser scanning microscopy (CLSM) analysis demonstrated similar results to the antibiofilm assays. The Bio-AgNP has antibacterial and antibiofilm activity and can be a promising therapeutic alternative against MDR bacteria.

Sustainable Antibacterial Surgical Suture Based on Recycled Silk Resource by an Internal Combination of Inorganic Nanomaterials

The current antibacterial treatment methods of silk sutures can only be finished by surface modification, leading to problems of short antibacterial effects, easy slow-release consumption, prominent toxicity, and susceptibility to drug resistance. Speculatively, surgical sutures combining antibacterial material internally will possess a more promising efficacy. Hence, we extracted recycled regenerated silk fibroin (RRSF) from waste silk resources to make RRSF solutions. Internally combining with inorganic titanium dioxide (TiO₂) nanoparticles, we fabricated antibacterial RRSF-based surgical sutures. The morphologies, mechanical and antibacterial properties, biocompatibility tests, and in vivo experiments were carried out. The results showed that the surgical sutures with 1.25 wt % TiO₂ acquired 2.40 N knot strength (143 μm diameter) and achieved a sustainable antibacterial effect of 93.58%. Surprisingly, the sutures significantly reduced inflammatory reactions and promoted wound healing. Surgical sutures in this paper realize high-value recovery of waste silk fibers and provide a novel approach to preparing multifunctional sutures.

Comparative Study Between Silver Nanoparticles Dressing (SilvrSTAT Gel) and Conventional Dressing in Diabetic Foot Ulcer Healing: A Prospective Randomized Study

BACKGROUND

We are trying to evaluate silver nanoparticles' effectiveness (SilvrSTAT Gel) in accelerating healing rate of nonischemic diabetic foot ulcers (DFUs).

METHODS

This prospective, double-blind, randomized, controlled study includes 80 patients with nonischemic DFUs classified into 2 groups. Group A was subjected to SilvrSTAT Gel dressing, and group B was subjected to conventional dressing (wet-to-moist dressing with or without povidone-iodine). All cases had minimal debridement before treatment. In both groups, all cases were nonischemic after successful revascularization either by bypass surgery or endovascular therapy.

RESULTS

The healing rate of the SilvrSTAT group was significantly higher than that of the conventional group. The healing rate per week of the SilvrSTAT group was considerably higher than that of the conventional group (P < .0001). The rate of complete healing for ulcers in group A was achieved in 22 patients (55%) by the 6th week, while 29 (72.5%), 34 (85%), and 36 (90%) patients were healed entirely by the 8th, 10th, and 12th weeks, respectively. In group B: 20 (50%), 27 (67.5%), and 30 (75%) patients were completeley healed by the 8th, 10th, and 12th weeks, respectively.

CONCLUSIONS

SilvrSTATGel is effective in the treatment of DFU.

Recent Advances in Silver Nanoparticles Containing Nanofibers for Chronic Wound Management

Infections are the primary cause of death from burns and diabetic wounds. The clinical difficulty of treating wound infections with conventional antibiotics has progressively increased and reached a critical level, necessitating a paradigm change for enhanced chronic wound care. The most prevalent bacterium linked with these infections is Staphylococcus aureus, and the advent of community-associated methicillin-resistant Staphylococcus aureus has posed a substantial therapeutic challenge. Most existing wound dressings are ineffective and suffer from constraints such as insufficient antibacterial activity, toxicity, failure to supply enough moisture to the wound, and poor mechanical performance. Using ineffective wound dressings might prolong the healing process of a wound. To meet this requirement, nanoscale scaffolds with their desirable qualities, which include the potential to distribute bioactive agents, a large surface area, enhanced mechanical capabilities, the ability to imitate the extracellular matrix (ECM), and high porosity, have attracted considerable interest. The incorporation of nanoparticles into nanofiber scaffolds constitutes a novel approach to “nanoparticle dressing” that has acquired significant popularity for wound healing. Due to their remarkable antibacterial capabilities, silver nanoparticles are attractive materials for wound healing. This review focuses on the therapeutic applications of nanofiber wound dressings containing Ag-NPs and their potential to revolutionize wound healing.

Biosynthesis of silver nanoparticles using extract of Rumex nepalensis for bactericidal effect against food-borne pathogens and antioxidant activity

The evolution and incidence of multidrug-resistant food-borne pathogens still become a critical public health global issue. To avert this challenge there is great interest in medical applications of silver nanoparticles. Thus, this study aimed to synthesize silver nanoparticles (Rn-AgNPs) using aqueous leaf extract of Nepal Dock (Rumex nepalensis Spreng) and evaluate their antibacterial potential against food-borne pathogens and antioxidant activity. The Rn-AgNPs were characterized by UV-Vis spectrophotometry, Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Fourier Transform Infra-Red Spectroscopy (FTIR). The antibacterial activities of the Rn-AgNPs were evaluated using agar well diffusion (zone of inhibition, ZOI) and microdilution (minimum inhibitory concentration, MIC and minimum bactericidal concentration, MBC) methods. The antioxidant property of the Rn-AgNPs was investigated using radical scavenging (DPPH and hydroxyl) assays. The UV-Vis spectra of Rn-AgNPs elucidated the absorption maxima at 425 nm and FTIR detected numerous functional groups of biological compounds that are responsible for capping and stabilizing Rn-AgNPs. DLS analysis displayed monodispersed Rn-AgNPs of 86.7 nm size and highly negative zeta potential (-32.5 mV). Overall results showed that Escherichia coli was the most sensitive organism, whereas Staphylococcus aureus was the least sensitive against Rn-AgNPs. In the antioxidant tests, the AgNPs radical scavenging activity reached 95.44% at 100 μg/ml. This study indicates that Rn-AgNPs exhibit a strong antimicrobial on L. monocytogenes, S. aureus, S. typhimurium, and E. coli and antioxidant and thus might be developed as a new type of antimicrobial agent for the treatment of multidrug-resistant foodborne pathogens and extensible applications in nanomaterial food- and nanocomposite-based antimicrobial packaging and/or as an antioxidant.

Allergies caused by textiles: control, research and future perspective in the medical field

Textile production forms one of the most polluting industries worldwide. However, other than damaging environmental effects, chemical waste products, such as formaldehyde or thiazolinone, are problematic for human health, as allergic potential is present in these compounds. Mostly, contact dermatitis occurs when human skin is exposed to textiles. Moreover, non-eczemous variants are mainly associated to textiles. In order to diagnose the possible allergy of the patient towards these compounds, in vivo and in vitro methods ca be performed, such as patch testing or cytokine detection assays, respectively. Newest research focuses on medical textiles such as garments or sutures to help in diagnosis, therapy and recovery of the patients. Sutures and dressings with antimicrobial properties, with the release of oxygen and growth factors offer greater properties. In this review, state of the art in the field as well as future perspectives will be discussed, which are based on the smart textiles that are going to become more important and probably widespread after the current limits exceeded.

Biogenic Synthesis and Characterization of Chitosan-CuO Nanocomposite and Evaluation of Antibacterial Activity against Gram-Positive and -Negative Bacteria

Chitosan-copper oxide (CHT-CuO) nanocomposite was synthesized using olive leaf extract (OLE) as reducing agent and CuSO4⋅5H2O as precursor. CHT-CuO nanocomposite was prepared using an in situ method in which OLE was added to a solution of chitosan and CuSO4⋅5H2O mixture in the ratio of 1:5 (v/v) and heated at a temperature of 90 °C. The obtained CHT-CuO nanocomposite was characterized using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectrophotometry, energy-dispersive X-ray spectroscopy (EDAX), Fourier transform infrared spectroscopy (FTIR), and high-resolution transmission electron microscopy (TEM). TEM results indicated that CHT-CuO nanocomposite are spherical in shape with size ranging from 3.5 to 6.0 nm. Antibacterial activity of the synthesized nanocomposites was evaluated against Gram-positive (Bacillus cereus, Staphyloccous haemolytica and Micrococcus Luteus) and Gram-negative (Escherichia coli, Pseudomonas citronellolis, Pseudomonas aeruginosa, kliebisella sp., Bradyrhizobium japonicum and Ralstonia pickettii) species by cup platting or disc diffusion method. Overall, against all tested bacterial strains, the diameters of the inhibition zone of the three nanocomposites fell between 6 and 24 mm, and the order of the antimicrobial activity was as follows: CuO-1.0 > CuO-0.5 > CuO-2.0. The reference antibiotic amoxicillin and ciprofloxacin showed greater activity based on the diameter of zones of inhibition (between 15−32 mm) except for S. heamolytica and P. citronellolis bacteria strains. The nanocomposites MIC/MBC were between 0.1 and 0.01% against all tested bacteria, except S. heamolityca (>0.1%). Based on MIC/MBC values, CuO-0.5 and CuO-1.0 were more active than CuO-2.0, in line with the observations from the disc diffusion experiment. The findings indicate that these nanocomposites are efficacious against bacteria; however, Gram-positive bacteria were less susceptible. The synthesized CHT-CuO nanocomposite shows promising antimicrobial activities and could be utilized as an antibacterial agent in packaging and medical applications.

Electrospun Medical Sutures for Wound Healing: A Review

With the increasing demand for wound healing around the world, the level of medical equipment is also increasing, but sutures are still the preferred medical equipment for medical personnel to solve wound closures. Compared with the traditional sutures, the nanofiber sutures produced by combining the preparation technology of drug-eluting sutures have greatly improved both mechanical properties and biological properties. Electrospinning technology has attracted more attention as one of the most convenient and simple methods for preparing functional nanofibers and the related sutures. This review firstly discusses the structural classification of sutures and the performance analysis affecting the manufacture and use of sutures, followed by the discussion and classification of electrospinning technology, and then summarizes the relevant research on absorbable and non-absorbable sutures. Finally, several common polymers and biologically active substances used in creating sutures are concluded, the related applications of sutures are discussed, and the future prospects of electrospinning sutures are suggested.

Optimization of Bacillus subtilis growth parameters for biosynthesis of silver nanoparticles by using response surface methodology

Silver nanoparticles (AgNPs) are among the most widely biosynthesized and used nanomaterials. They have different unique properties and a wide range of applications. This study is concerned with optimization of the growth conditions of Bacillus subtilis NRC1 for the biosynthesis of AgNPs using two designs of response surface methodology (RSM) statistical analysis. The data obtained from Plackett-Burman design (PBD) followed by central composite design (CCD), showed a good agreement between the experimental and predicted values of AgNPs biosynthesis. The optimum conditions were 0.7% (w/v) casein hydrolysate, 5% dextrin (w/v), pH 7.5 and 57 × 10⁶ CFU/ml inoculum size. The model was highly valid and could be applied with a confidence factor of 99.47%. Minimal inhibitory concentration (MIC) of these AgNPs synthesized using the extracellular filtrate after growth of Bacillus subtilis NRC1 in the optimized medium was found to be 41-43µg/ml for all tested microorganisms with exception of Pseudomonas aeruginosa where MIC was 169 µg/ml.

Benefit of Silver and Gold Nanoparticles in Wound Healing Process after Endometrial Cancer Protocol

It is intractable to manage the vast majority of wounds in a classical surgical manner, however if silver, likewise gold and its representative nanoparticles, can lead to the amelioration of the wound healing process after extensive procedures, they should be employed in the current gynecological practice as promptly as possible. Most likely due to its antimicrobial properties, silver is usually applied as an additional component in the wound healing process. In wound management, we obtained various aspects that can lead to impaired wound healing; the crucial aspect for the wound milieu is to prevent the offending agents from occurring. The greatest barrier to healing is represented by the bacterial biofilm, which can occur naturally or in other ways. Biofilm bacteria can produce extracellular polymers, which can then resist concentrated anti-bacterial treatment. The published literature on the use of silver nanoparticles' utilization in wound healing becomes slightly heterogenous and requires us in difficult moments to set up proper treatment guidelines.

Sustainable Antibacterial and Anti-Inflammatory Silk Suture with Surface Modification of Combined-Therapy Drugs for Surgical Site Infection

Silk sutures with antibacterial and anti-inflammatory functions were developed for sustained dual-drug delivery to prevent surgical site infections (SSIs). The silk sutures were prepared with core-shell structures braided from degummed silk filaments and then coated with a silk fibroin (SF) layer loaded with berberine (BB) and artemisinin (ART). Both the rapid release of drugs to prevent initial biofilm formation and the following sustained release to maintain effective concentrations for more than 42 days were demonstrated. In vitro assays using human fibroblasts (Hs 865.Sk) demonstrated cell proliferation on the materials, and hemolysis was 2.4 ± 0.8%, lower than that required by ISO 10993-4 standard. The sutures inhibited platelet adhesion and promoted collagen deposition and blood vessel formation. In vivo assessments using Sprague-Dawley (SD) rats indicated that the coating reduced the expression of pro-inflammatory cytokines interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α), shortening the inflammatory period and promoting angiogenesis. The results demonstrated that these new sutures exhibited stable structures, favorable biocompatibility, and sustainable antibacterial and anti-inflammatory functions with potential for surgical applications.

Proteome-wide analysis reveals molecular pathways affected by AgNP in a ROS-dependent manner

The use of mass spectrometry-based proteomics has been increasingly applied in nanomaterials risk assessments as it provides a proteome-wide overview of the molecular disturbances induced by its exposure. Here, we used this technique to gain detailed molecular insights into the role of ROS as an effector of AgNP toxicity, by incubating Bend3 cells with AgNP in the absence or presence of an antioxidant N-acetyl L-cystein (NAC). ROS generation is a key player in AgNP-induced toxicity, as cellular homeostasis was kept in the presence of NAC. By integrating MS/MS data with bioinformatics tools, in the absence of NAC, we were able to pinpoint precisely which biological pathways were affected by AgNP. Cells respond to AgNP-induced ROS generation by increasing their antioxidant pool, via NRF2 pathway activation. Additionally, cell proliferation-related pathways were strongly inhibited in a ROS-dependent manner. These findings reveal important aspects of the AgNP mechanism of action at the protein level.

Therapeutic Applications of Antimicrobial Silver-Based Biomaterials in Dentistry

Microbial infection accounts for many dental diseases and treatment failure. Therefore, the antibacterial properties of dental biomaterials are of great importance to the long-term results of treatment. Silver-based biomaterials (AgBMs) have been widely researched as antimicrobial materials with high efficiency and relatively low toxicity. AgBMs have a broad spectrum of antimicrobial properties, including penetration of microbial cell membranes, damage to genetic material, contact killing, and dysfunction of bacterial proteins and enzymes. In particular, advances in nanotechnology have improved the application value of AgBMs. Hence, in many subspecialties of dentistry, AgBMs have been researched and employed, such as caries arresting or prevention, root canal sterilization, periodontal plaque inhibition, additives in dentures, coating of implants and anti-inflammatory material in oral and maxillofacial surgery. This paper aims to provide an overview of the application approaches of AgBMs in dentistry and present better guidance for oral antimicrobial therapy via the development of AgBMs.

Engineering surgical stitches to prevent bacterial infection

Surgical site infections (SSIs) account for a massive economic, physiological, and psychological burden on patients and health care providers. Sutures provide a surface to which bacteria can adhere, proliferate, and promote SSIs. Current methods for fighting SSIs involve the use of sutures coated with common antibiotics (triclosan). Unfortunately, these antibiotics have been rendered ineffective due to the increasing rate of antibiotic resistance. A promising new avenue involves the use of metallic nanoparticles (MNPs). MNPs exhibit low cytotoxicity and a strong propensity for killing bacteria while evading the typical antibiotic resistance mechanisms. In this work, we developed a novel MNPs dip-coating method for PDS-II sutures and explored the capabilities of a variety of MNPs in killing bacteria while retaining the cytocompatibility. Our findings indicated that our technique provided a homogeneous coating for PDS-II sutures, maintaining the strength, structural integrity, and degradability. The MNP coatings possess strong in vitro antibacterial properties against P aeruginosa and S. aureus—varying the %of dead bacteria from ~ 40% (for MgO NPs) to ~ 90% (for Fe₂O₃) compared to ~ 15% for uncoated PDS-II suture, after 7 days. All sutures demonstrated minimal cytotoxicity (cell viability > 70%) reinforcing the movement towards the use MNPs as a viable antibacterial technology.

Biofilms in Surgical Site Infections: Recent Advances and Novel Prevention and Eradication Strategies

Surgical site infections (SSIs) are common postoperative occurrences due to contamination of the surgical wound or implanted medical devices with community or hospital-acquired microorganisms, as well as other endogenous opportunistic microbes. Despite numerous rules and guidelines applied to prevent these infections, SSI rates are considerably high, constituting a threat to the healthcare system in terms of morbidity, prolonged hospitalization, and death. Approximately 80% of human SSIs, including chronic wound infections, are related to biofilm-forming bacteria. Biofilm-associated SSIs are extremely difficult to treat with conventional antibiotics due to several tolerance mechanisms provided by the multidrug-resistant bacteria, usually arranged as polymicrobial communities. In this review, novel strategies to control, i.e., prevent and eradicate, biofilms in SSIs are presented and discussed, focusing mainly on two attractive approaches: the use of nanotechnology-based composites and natural plant-based products. An overview of new therapeutic agents and strategic approaches to control epidemic multidrug-resistant pathogenic microorganisms, particularly when biofilms are present, is provided alongside other combinatorial approaches as attempts to obtain synergistic effects with conventional antibiotics and restore their efficacy to treat biofilm-mediated SSIs. Some detection and real-time monitoring systems to improve biofilm control strategies and diagnosis of human infections are also discussed.

A nanosecond pulsed laser-ablated MWCNT-Au heterostructure: an innovative ultra-sensitive electrochemical sensing prototype for the identification of glutathione

Here, a scheme that aptly describes the reduction of gold nanoparticles’ crystalline size on the surface of MWCNTs in an aqueous phase to generate a LAMWCNT-Au heterostructure, employing an Nd:YAG laser (energy = 505 mJ and λ = 1064 nm) is developed.

Enhanced antimicrobial treatment by a clay-based drug nanocarrier conjugated to a guanidine-rich cell penetrating peptide

In this study, a novel and efficient drug delivery system is proposed for the enhancement of antimicrobial properties of antibiotic medications such as vancomycin (VCM) and levofloxacin (OFX). The architecture of the designed drug carrier is based on halloysite nanotubes (HNTs) with a rolled-laminate shape, suitable for the encapsulation of drug and further release. In order to make them capable for magnetic direction to the target tissue, the exterior surface of the tubes is composed of iron oxide nanoparticles (Fe₃O₄ NPs), via an in situ process. The main role in the antimicrobial activity enhancement is played by a cell-penetrating peptide (CPP) sequence synthesized in the solid phase, which contains three arginine–tryptophan blocks plus a cysteine as the terminal amino acid (C(WR)₃). The drug content values for the prepared nanocargoes named as VCM@Fe₃O₄/HNT–C(WR)₃ and OFX@Fe₃O₄/HNT–C(WR)₃, have been estimated at ca. 10 wt% and 12 wt%, respectively. Also, the drug release investigations have shown that above 90% of the encapsulated drug is released in acetate buffer (pH = 4.6), during a 90 minutes process. Confocal microscopy has corroborated good adhesion and co-localization of the particles and the stained living cells. Moreover, in vitro antimicrobial assessments (optical density, zone of inhibition, and minimum inhibitory concentration) have revealed that the bacterial cell growth rate is significantly inhibited by suggested nanocargoes, in comparison with the individual drugs in the same dosage. Hence, administration of the presented nanocargoes is recommended for the clinical treatment of the infected target organ.

A novel anti-infection therapeutic nano-bioconjugate based on magnetized halloysite nanotubes and a CPP is presented. High levels of bactericidal effects have been obtained with the designed nanocargo in comparison with the individual drugs.

Exploring silver nanoparticles for cancer therapy and diagnosis

Nanomaterials have emerged as promising candidates for cancer therapy and diagnosis as they can solve long-term issues such as drug solubility, systemic distribution, tumor acquired resistance, and improve the performance of diagnostic methods. Among inorganic nanomaterials, AgNPs have been extensively studied in the context of cancer treatment and the reported results have raised exciting expectations. In this review, we provide an overview of the recent research on AgNPs antitumoral properties, their application in different cancer treatment modalities, their potential in biosensors development, and also highlight the main challenges and possible strategies to enable its translation to clinical use.

Potential of Nanoparticles Integrated with Antibacterial Properties in Preventing Biofilm and Antibiotic Resistance

Nanotechnology has become an emerging technology in the medical field and is widely applicable for various clinical applications. The potential use of nanoparticles as antimicrobial agents is greatly explored and taken into consideration as alternative methods to overcome the challenges faced by healthcare workers and patients in preventing infections caused by pathogenic microorganisms. Among microorganisms, bacterial infections remain a major hurdle and are responsible for high morbidity and mortality globally, especially involving those with medical conditions and elderly populations. Over time, these groups are more vulnerable to developing resistance to antibiotics, as bacterial biofilms are difficult to destroy or eliminate via antibiotics; thus, treatment becomes unsuccessful or ineffective. Mostly, bacterial biofilms and other microbes can be found on medical devices and wounds where they disperse their contents which cause infections. To inhibit biofilm formations and overcome antibiotic resistance, antimicrobial-loaded nanoparticles alone or combined with other substances could enhance the bactericidal activity of nanomaterials. This includes killing the pathogens effectively without harming other cells or causing any adverse effects to living cells. This review summarises the mechanisms of actions employed by the different types of nanoparticles which counteract infectious agents in reducing biofilm formation and improve antibiotic therapy for clinical usage.

Striking Back against Fungal Infections: The Utilization of Nanosystems for Antifungal Strategies

Fungal infections have become a major health concern, given that invasive infections by Candida, Cryptococcus, and Aspergillus species have led to millions of mortalities. Conventional antifungal drugs including polyenes, echinocandins, azoles, allylamins, and antimetabolites have been used for decades, but their limitations include off-target toxicity, drug-resistance, poor water solubility, low bioavailability, and weak tissue penetration, which cannot be ignored. These drawbacks have led to the emergence of novel antifungal therapies. In this review, we discuss the nanosystems that are currently utilized for drug delivery and the application of antifungal therapies.

Bioactive Khadi Cotton Fabric by Functional Designing and Immobilization of Nanosilver Nanogels

The antimicrobial finishing is the most suitable alternative for designing medical textiles for biomedical applications. The present investigation aims at the preparation of skin-contacting khadi cotton fabric that would prevent microbial infection and offer excellent skin compatibility. A simple approach has been followed for the preparation of bioactive nanogels for antimicrobial finishing of the khadi cotton fabric. Bioactive nanogels were synthesized by using aloe vera (AV) as a reducing agent for silver ions in the presence of polyvinyl alcohol (PVA). PVA stabilizes the growth of silver nanoparticles, which is influenced by the variation in the reaction time and the temperature. Nanogels were characterized by transmission electron microscopy and scanning electron microscopy analyses. The nanogels exhibited strong antimicrobial behavior against both Staphylococcus aureus and Escherichia coli, as confirmed by the colony count method. Almost 100% antibacterial behavior was observed for the nanosilver content of 10 mM. The nanogel-finished khadi fabric showed bactericidal properties against both S. aureus and E. coli. The nanogel-finished fabric exhibited high hydrophilicity allowing complete water droplet penetration within 10 s as compared to 136 s in virgin fabric. Moreover, the skin irritation study of the fabric on male Swiss albino mice did not show any appearance of dermal toxicity. These results demonstrated that the bioactive finished khadi fabric is appropriate as skin contacting material in human health care.

Facile Synthesis of Bio-Antimicrobials with "Smart" Triiodides

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I₂) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I₂. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I₂ showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I₂ and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.

Green synthesis of silver nanoparticles from aqueous extract of Scutellaria barbata and coating on the cotton fabric for antimicrobial applications and wound healing activity in fibroblast cells (L929)

Scutellaria barbata is a perennial herb which was vastly prescribed in Chinese medicine to treat inflammations, infections and it is also used a detoxifying agent. We synthesized silver nanoparticles with Scutellaria barbata extract and characterized the nanoparticles with UV–Vis spectroscopic analysis, TEM, AFM, FTIR and XRD. The biofilm inhibiting property of synthesized silver nanoparticles were examined with XTT reduction assay and the antimicrobial property was examined with well diffusion method. The silver nanoparticles were also coated with cotton fabrics and their efficacy against antimicrobials was analyzed to prove its application. The cytotoxic property of synthesized silver nanoparticles was examined with L929 fibroblast cells using MTT assay. Finally we analyzed the wound healing property of synthesized silver nanoparticles with wound scratch assay. The result of our UV–Vis spectroscopic analysis confirms Scutellaria barbata aqueous extract reduced silver ions and synthesized silver nanoparticles. The characterization studies TEM, AFM, FTIR and XRD confirms the synthesized silver nanoparticles are in ideal shape and size to be utilized as a drug. The XTT reduction assay proves silver nanoparticles effectively inhibits the biofilm formation in both resistant and sensitive strains. Antimicrobial sensitivity tests confirms synthesized silver nanoparticles and cotton coated synthesized silver nanoparticles both are effective against gram positive, gram negative and fungal species. Further the results of MTT assay confirms the synthesized silver nanoparticles are non toxic and finally the wound healing potency of the nanoparticles was confirmed with wound scratch assay. Over all our results authentically confirms the silver nanoparticles synthesized with Scutellaria barbata aqueous extract is potent wound healing drug.

Engineering and polymeric composition of drug-eluting suture: A review

Sutures are the most popular surgical implants in the global surgical equipment market. They are used for holding tissues together to achieve wound closure. However, controlling the body's immune response to these "foreign bodies" at site of infection is challenging. Natural polymers such as collagen, silk, nylon, and cotton, and synthetic polymers such as polycaprolactone, poly(lactic-co-glycolic acid), poly(p-dioxanone) and so forth, contribute the robust foundation for the engineering of drug-eluting sutures. The incorporation of active pharmaceutical ingredients (APIs) with polymeric composition of suture materials is an efficient way to reduce inflammatory reaction in the wound site as well as to control bacterial growth, while allowing wound healing. The incorporation of polymeric composition in surgical sutures has been found to add high flexibility as well as excellent physical and mechanical properties. Fabrication processes and polymer materials allow control over drug-eluting profiles to effectively address wound healing requirements. This review outlines and discusses (a) polymer materials and APIs used in suture applications, including absorbable and nonabsorbable sutures; (b) suture structures, such as monofilament, multifilament, barded and smart sutures; and (c) the existing manufacturing techniques for drug-eluting suture production, including electrospinning, melt-extrusion and coating.

Green synthesized Silver Nanoparticles as Silver Lining in Antimicrobial Resistance: A Review

Unprincipled use of antibiotics has led to the antimicrobial resistance (AMR) against mostly available compounds and now become a major cause of concern for the scientific community. However, in the past decade, green synthesized silver nanoparticles (AgNPs) have received greater attention for the development of newer therapies as antimicrobials by virtue of their unique physico-chemical properties. Unlike traditional antibiotics, AgNPs exert their action by acting on multiple mechanisms which make them potential candidates against AMR. Green synthesis of AgNPs using various medicinal plants has demonstrated broader spectrum of action against several microbes in a number of attempts. The present paper provides an insight into the scientific studies that have elucidated the positive role of plant extracts/phytochemicals during green synthesis of AgNPs and their future perspectives. The studies conducted so far seem promising still, a few factors like, the precise mechanism of action of AgNPs, their synergistic interaction with biomolecules, and industrial scalability need to be explored further till effective drug development using green synthesized AgNPs in healthcare systems against AMR is established.

Effect of the Melicoccus bijugatus leaf and fruit extracts and acidic solvents on the antimicrobial properties of chitosan-starch films

AIM

Analysing the antimicrobial activity-against food-borne micro-organisms-of modified chitosan-starch films using formic and acetic acid as chitosan solvents and Melicoccus bijugatus leaves and fruit extracts.

METHODS AND RESULTS

The films' antimicrobial activity against mesophilic aerobic bacteria, total coliform and fungi were also analysed, in accordance with the Mexican Official Norms (NOM-092-SSA1-1994, NOM-111-SSA1-1994 and NOM-113-SSA1-1994). The pH values of the films and extracts were measured, and the volatile compounds of the extracts and two films were determined by Gas Chromatography-Mass Spectrometry (GC-MS) considering the relationship among the type of compounds, extracts concentration, films' pH and the antimicrobial activity against bacteria and fungi. The best results are obtained by films with formic acid and 10% (v/v) of leaf and fruit extracts, in comparison with untreated chitosan-starch films.

CONCLUSIONS

The extracts' compounds improved the films' antimicrobial capacity and inhibited the growth of micro-organisms with no previous sterilization required. It is correlated to the pH of the media, the combination of solvent/extract used and its concentration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is one of the few researches where the antimicrobial activity of M. bijugatus extracts is studied. It was found that the presence of these extracts is capable of improving the antimicrobial activities of chitosan-starch films. The performance of the modified films suggests their potential application as novel food packaging materials and encourages further research.

Chitosan-Coated Surgical Sutures Prevent Adherence and Biofilms of Mixed Microbial Communities

Sutures are widely used materials for closing the surgical wounds, and being an inert material, sutures are often colonized with drug-resistant polymicrobial biofilms. Surgical site infection (SSI) is a hospital-acquired infection caused by bacteria and fungi specifically in the sutured sites. Although most of the currently available sutures possess antibacterial property, their ability to prevent biofilm colonization by polymicrobial communities is underexplored. So, the present study shows that extracted chitosan (EC) from crab shells prevented the adherence of Staphylococcus epidermidis and Candida albicans, the predominant members that exist as mixed species at the site of SSI. In comparison with a commercial chitosan, EC showed profound inhibition of slime formation and mixed species biofilm inhibition. Intriguingly, EC-coated sutures could inhibit the growth of both bacterial and fungal pathogens when comparing with a commercial triclosan-coated suture which was active only against the bacterial pathogen. Scanning electron microscopy results revealed inhibition of C. albicans hyphal formation by the EC-coated sutures that is a crucial virulence factor responsible for tissue invasiveness. Collectively, the results of the present study showed that EC from crab shells (discarded material as a recalcitrant biowaste) could be used as an alternative to combat drug-resistant biofilms which are the prime cause for SSIs.

Facile green bio-fabricated silver nanoparticles from Microchaete infer dose-dependent antioxidant and anti-proliferative activity to mediate cellular apoptosis

With the rapid development of nanotechnology, much has been anticipated with silver nanoparticles (AgNPs) due to their extensive industrial and commercial applications. However, it has raised concerns over environmental safety and human health effects. In this study, AgNPs were bio-fabricated using aqueous extract of Microchaete and their medical applications like antioxidant, anti-proliferative, and apoptosis were done. The biosynthesis of AgNPs was continuously followed by UV-vis spectrophotometric analysis. The physiochemical properties like shape, size, crystallinity, and polydispersity of the nanoparticles were determined by Scanning Electron Microscopy (SEM) along with EDX, Transmission Electron Microscope (TEM), Atomic Force Microscope (AFM), dynamic light scattering (DLS), and X-Ray Diffraction (XRD). Biosynthesized 7.0 nm sized AgNPs with the crystalline structure (crystalline size 4.8 nm) having a hydrodynamic diameter of 38.74 ± 2.6 nm was achieved due to the involvement of reducing agents present in the cyanobacterial extract. The IC₅₀ values of the AgNPs were evaluated as 75 µg/ml and 79.41 µg/ml with HepG2 and MCF-7 cell lines. Different in-vitro cellular assays investigated in the present study exhibited antioxidant, anti-proliferative, and apoptotic activities. Probably delayed apoptosis in HepG2 and MCF-7 is due to better antioxidant activities of Microchaete based AgNPs.

Metal Nanoparticles for Electrochemical Sensing: Progress and Challenges in the Clinical Transition of Point-of-Care Testing

With the rise in public health awareness, research on point-of-care testing (POCT) has significantly advanced. Electrochemical biosensors (ECBs) are one of the most promising candidates for the future of POCT due to their quick and accurate response, ease of operation, and cost effectiveness. This review focuses on the use of metal nanoparticles (MNPs) for fabricating ECBs that has a potential to be used for POCT. The field has expanded remarkably from its initial enzymatic and immunosensor-based setups. This review provides a concise categorization of the ECBs to allow for a better understanding of the development process. The influence of structural aspects of MNPs in biocompatibility and effective sensor design has been explored. The advances in MNP-based ECBs for the detection of some of the most prominent cancer biomarkers (carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), Herceptin-2 (HER2), etc.) and small biomolecules (glucose, dopamine, hydrogen peroxide, etc.) have been discussed in detail. Additionally, the novel coronavirus (2019-nCoV) ECBs have been briefly discussed. Beyond that, the limitations and challenges that ECBs face in clinical applications are examined and possible pathways for overcoming these limitations are discussed.