Dynamic Hydrogels against Infections: From Design to Applications.

Human defense against infection remains a global topic. In addition to developing novel anti-infection drugs, therapeutic drug delivery strategies are also crucial to achieving a higher efficacy and lower toxicity of these drugs for treatment. The application of hydrogels has been proven to be an effective localized drug delivery approach to treating infections without generating significant systemic adverse effects. The recent emerging dynamic hydrogels further show power as injectable formulations, giving new tools for clinical treatments. In this review, we delve into the potential applications of dynamic hydrogels in antibacterial and antiviral treatments and elaborate on their molecular designs and practical implementations. By outlining the chemical designs underlying these hydrogels, we discuss how the choice of dynamic chemical bonds affects their stimulus responsiveness, self-healing capabilities, and mechanical properties. Afterwards, we focus on how to endow dynamic hydrogels with anti-infection properties. By comparing different drug-loading methods, we highlight the advantages of dynamic chemical bonds in achieving sustained and controlled drug release. Moreover, we also include the design principles and uses of hydrogels that possess inherent anti-infective properties. Furthermore, we explore the design principles and applications of hydrogels with inherent anti-infective properties. Finally, we briefly summarize the current challenges faced by dynamic hydrogels and present a forward-looking vision for their future development. Through this review, we expect to draw more attention to these therapeutic strategies among scientists working with chemistry, materials, as well as pharmaceutics.

A comprehensive review of medium chain monoglycerides on metabolic pathways, nutritional and functional properties, nanotechnology formulations and applications in food system.

A large and growing body of literature has investigated the broad antibacterial spectrum and strong synergistic antimicrobial activity of medium chain monoglycerides (MCMs) have been widely investigated. Recently, more and more researches have focused on the regulation of MCMs on metabolic health and gut microbiota both in vivo and in vitro. The current review summarizes the digestion, absorption and metabolism of MCMs. Subsequently, it focuses on the functional and nutritional properties of MCMs, including the antibacterial and antiviral characteristics, the modulation of metabolic balance, the regulation of gut microbiota, and the improvement in intestinal health. Additionally, we discuss the most recent developments and application of MCMs using nanotechnologies in food industry, poultry and pharmaceutical industry. Additionally, we analyze recent application examples of MCMs and their nanotechnology formation used in food. The development of nanotechnology platforms facilitating molecular encapsulation and functional presentation contribute to the application of hydrophobic fatty acids and monoglycerides in food preservation and their antibacterial effectiveness. This study emphasizes the metabolic mechanisms and biological activity of MCMs by summarizing the prevailing state of knowledge on this topic, as well as providing insights into prospective techniques for developing the beneficial applications of MCMs to realize the industrialized production.

Antimicrobial and Antiviral Nanofibers Halt Co-Infection Spread via Nuclease-Mimicry and Photocatalysis.

The escalating spread of drug-resistant bacteria and viruses is a grave concern for global health. Nucleic acids dominate the drug-resistance and transmission of pathogenic microbes. Here, imidazolium-type poly(ionic liquid)/porphyrin (PIL-P) based electrospun nanofibrous membrane and its cerium (IV) ion complex (PIL-P-Ce) are developed. The obtained PIL-P-Ce membrane exhibits high and stable efficiency in eradicating various microorganisms (bacteria, fungi, and viruses) and decomposing microbial antibiotic resistance genes and viral nucleic acids under light. The nuclease-mimetic and photocatalytic mechanisms of the PIL-P-Ce are elucidated. Co-infection wound models in mice with methicillin-resistant S. aureus and hepatitis B virus demonstrate that PIL-P-Ce integrate the triple effects of cationic polymer, photocatalysis, and nuclease-mimetic activities. As revealed by proteomic analysis, PIL-P-Ce shows minimal phototoxicity to normal tissues. Hence, PIL-P-Ce has potential as a "green" wound dressing to curb the spread of drug-resistant bacteria and viruses in clinical settings.

Therapeutic Use of Bee Venom and Potential Applications in Veterinary Medicine.

Apitherapy is a branch of alternative medicine that consists of the treatment of diseases through products collected, processed, and secreted by bees, specifically pollen, propolis, honey, royal jelly, and bee venom. In traditional medicine, the virtues of honey and propolis have been well-known for centuries. The same, however, cannot be said for venom. The use of bee venom is particularly relevant for many therapeutic aspects. In recent decades, scientific studies have confirmed and enabled us to understand its properties. Bee venom has anti-inflammatory, antioxidant, central nervous system inhibiting, radioprotective, antibacterial, antiviral, and antifungal properties, among others. Numerous studies have often been summarised in reviews of the scientific literature that have focused on the results obtained with mouse models and their subsequent transposition to the human patient. In contrast, few reviews of scientific work on the use of bee venom in veterinary medicine exist. This review aims to take stock of the research achievements in this particular discipline, with a view to a recapitulation and stabilisation in the different research fields.

Thermoplastic elastomers containing antimicrobial and antiviral additives for mobility applications.

The transmission of the SARS-CoV-2 coronavirus has been shown through droplets generated by infected people when coughing, sneezing, or talking in close contact. These droplets either reach the next person directly or land on nearby surfaces. The objective of this study is to develop a novel, durable, and effective disinfecting antimicrobial (antiviral, antibacterial, and antifungal) styrene-ethylene/butylene-styrene (SEBS) based thermoplastic elastomers (TPE). TPE incorporated with six different formulations was investigated for mechanical and antiviral performance. The formulations consist of a combination of zinc pyrithione (ZnPT), sodium pentaborate pentahydrate (NaB), disodium octaborate tetrahydrate (DOT), and chlorhexidine (CHX). ZnPT and DOT incorporated TPE showed a reduction of microbes such as bacteria by up to 99.99%, deactivated Adenovirus, Poliovirus, Norovirus, and reduced a strain of the coronavirus family by 99.95% in 60 min on TPE samples. Control samples had higher tensile strengths among all formulations and tensile strength decreased by around 14%, 21% and 27% for ZnPT and DOT combinations compared to control samples. The elongation at break decreased by around 7%, 9% and 12% with ZnPT and DOT combinations, where it reached minimum values of 720%, 702% and 684%, respectively. The 100% Modulus and 300% Modulus slightly increased with ZnPT and NaB combination (reaching values from 1.6 to 1.9 MPa and 2.6-2.9 MPa respectively) in comparison with control samples. The MFI also decreased with antimicrobial and antiviral additives (decreasing values from 64.8 to 43.3 g/10 min). ZnPT and NaB combination showed the lowest MFI (43.3 g/10 min) and reduced the MFI of control sample by around 33%. TPE samples containing ZnPT and DOT combination showed biocidal activity against the microorganisms tested and can be used to develop antimicrobial products for multiple touchpoints within a vehicle and micro-mobility.

Structure-Morphology-Antimicrobial and Antiviral Activity Relationship in Silver-Containing Nanocomposites Based on Polylactide.

Green synthesis of silver-containing nanocomposites based on polylactide (PLA) was carried out in two ways. With the use of green tea extract, Ag+ ions were reduced to silver nanoparticles with their subsequent introduction into the PLA (mechanical method) and Ag+ ions were reduced in the polymer matrix of PLA-AgPalmitate (PLA-AgPalm) (in situ method). Structure, morphology and thermophysical properties of nanocomposites PLA-Ag were studied by FTIR spectroscopy, wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) methods. The antimicrobial, antiviral, and cytotoxic properties were studied as well. It was found that the mechanical method provides the average size of silver nanoparticles in the PLA of about 16 nm, while in the formation of samples by the in situ method their average size was 3.7 nm. The strong influence of smaller silver nanoparticles (3.7 nm) on the properties of nanocomposites was revealed, as with increasing nanosilver concentration the heat resistance and glass transition temperature of the samples decreases, while the influence of larger particles (16 nm) on these parameters was not detected. It was shown that silver-containing nanocomposites formed in situ demonstrate antimicrobial activity against gram-positive bacterium S. aureus, gram-negative bacteria E. coli, P. aeruginosa, and the fungal pathogen of C. albicans, and the activity of the samples increases with increasing nanoparticle concentration. Silver-containing nanocomposites formed by the mechanical method have not shown antimicrobial activity. The relative antiviral activity of nanocomposites obtained by two methods against influenza A virus, and adenovirus serotype 2 was also revealed. The obtained nanocomposites were not-cytotoxic, and they did not inhibit the viability of MDCK or Hep-2 cell cultures.

Preparation, Characterization, and Antimicrobial and Antiviral Properties of Silver-Containing Nanocomposites Based on Polylactic Acid-Chitosan.

Antimicrobial and antiviral nanocomposites based on polylactic acid (PLA) and chitosan were synthesized by a thermochemical reduction method of Ag+ ions in the PLA-Ag+-chitosan polymer films. Features of the structural, morphological, thermophysical, antimicrobial, antiviral, and cytotoxic properties of PLA-Ag-chitosan nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and antiviral, antimicrobial, and cytotoxic studies. The effects of temperature and the duration of reduction of Ag+ ions on the structure of PLA-Ag-chitosan nanocomposites were established. During the thermochemical reduction (T = 160 °C, t = 5 min) of silver palmitate ions in PLA-Ag+-chitosan polymer films, Ag nanoparticles with an average size of 4.2 nm were formed. PLA-Ag-chitosan polymer nanocomposites have strong antimicrobial activity against S. aureus and E. coli strains. In particular, for PLA-chitosan samples containing 4% Ag, the diameters of the S. aureus and E. coli growth inhibition zones were 25.8 and 25.0 mm, respectively. The antiviral activity of the nanocomposites against influenza A virus, herpes simplex virus type 1, and adenovirus serotype 2 was also revealed. The PLA-4%Ag-chitosan nanocomposites completely inhibited the cytopathic effect (CPE) of herpes virus type 1 by 5.12 log10TCID50/mL (high antiviral activity) and the development of the CPE of influenza virus and adenovirus by 0.60 and 1.07 log10TCID50/mL (relative antiviral activity). The obtained nanocomposites were not cytotoxic; they did not inhibit the viability of MDCK, BHK-21, and Hep-2 cell cultures.

An evaluation of antimicrobial potential of irreversible hydrocolloid impression material incorporated with chitosan.

AIM: To evaluate the antimicrobial potential of irreversible hydrocolloid impression material manipulated using chitosan impregnated solution at various time intervals. SETTING AND DESIGN: Evaluative invivo study design. MATERIALS AND METHODS: Maxillary impressions made for 20 dentulous volunteers using irreversible hydrocolloid impression material manipulated using distilled water as control and using 1% chitosan impregnated solution as test group using stock metal trays with one-week interval. Bacterial samples were collected using dry sterile cotton swab in the mid-palatal region at the time intervals of 0, 10, 20 minutes. Bacterial swabs were inoculated on nutrient agar media and incubated at 37° C for 24 hours. Bacterial colonies were counted with the aid of colony counter. STATISTICAL ANALYSIS USED: The resultant data was subjected to statistical analysis using repeated measures ANOVA and independent t test. RESULTS: Adding water soluble chitosan to irreversible hydrocolloid impression material resulted in superior antimicrobial activity. With the passage of time there was a significant decrease in the microbial colony count upto 10min (p=0.016). However, the rate of decrease of microbial colony count was statistically insignificant between the samples collected at 10 and 20 min. CONCLUSION: Incorporation of water soluble chitosan to irreversible hydrocolloid impression material showed significant antimicrobial activity in 10 minutes.

Daylight-Induced Antibacterial and Antiviral Nanofibrous Membranes Containing Vitamin K Derivatives for Personal Protective Equipment.

During the development of antibacterial and antiviral materials for personal protective equipment (PPE), daylight active functional polymeric materials containing vitamin K compounds (VKs) and impacts of polymer structures to the functions were investigated. As examples, hydrophobic polyacrylonitrile (PAN) and hydrophilic poly(vinyl alcohol-co-ethylene) (PVA-co-PE) polymers were directly blended with three VK compounds and electrospun into VK-containing nanofibrous membranes (VNFMs). The prepared VNFMs exhibited robust photoactivity in generating reactive oxygen species (ROS) under both daylight (D65, 300-800 nm) and ultraviolet A (UVA, 365 nm) irradiation, resulting in high antimicrobial and antiviral efficiency (>99.9%) within a short exposure time (<90 min). Interestingly, the PVA-co-PE/VK3 VNFM showed higher ROS production rates and better biocidal functions than those of the PAN/VK3 VNFM under the same photoirradiation conditions, indicating that PVA-co-PE is a better matrix polymer material for these functions. Moreover, the prepared PVA-co-PE/VK3 VNFM maintains its powerful microbicidal function even after five times of repeated exposures to bacteria and viruses, showing the stability and reusability of the antimicrobial materials. The fabrication of photoinduced antimicrobial VNFMs may provide new insights into the development of non-toxic and reusable photoinduced antimicrobial materials that could be applied in personal protective equipment with improved biological protections.

Transcriptional networks in the human epididymis.

BACKGROUND: The epithelial lining of the human epididymis is critical for sperm maturation. This process requires distinct specialized functions in the head, body, and tail of the duct. These region-specific properties are maintained by distinct gene expression profiles which are governed by transcription factor networks, non-coding RNAs, and other factors. MATERIALS AND METHODS: We used genome-wide protocols including DNase-seq, RNA-seq and ChIP-seq to characterize open (active) chromatin, the transcriptome and occupancy of specific transcription factors (TFs) respectively, in caput, corpus, and cauda segments of adult human epididymis tissue and primary human epididymis epithelial (HEE) cell cultures derived from them. RNA-seq following TF depletion or activation, combined with gene ontology analysis also determined TF targets. RESULTS: Among regional differentially expressed transcripts were epithelial-selective transcription factors (TFs), microRNAs, and antiviral response genes. Caput-enriched TFs included hepatocyte nuclear factor 1 (HNF1) and the androgen receptor (AR), both of which were also predicted to occupy cis-regulatory elements identified as open chromatin in HEE cells. HNF1 targets were identified genome-wide using ChIP-seq, in HEE cells. Next, siRNA-mediated depletion of HNF1 revealed a pivotal role for this TF in coordinating epithelial water and solute transport in caput epithelium. The importance of AR in HEE cells was shown by AR ChIP-seq, and by RNA-seq after synthetic androgen (R1881) treatment. AR has a distinct transcriptional program in the HEE cells and likely recruits different co-factors (RUNX1 and CEBPß) in comparison to those used in prostate epithelium. DISCUSSION AND CONCLUSION: Our data identify many transcription factors that regulate the development and differentiation of HEE cells. Moreover, a comparison between immature and adult HEE cells showed key TFs in the transition to fully differentiated function of this epithelium. These data may help identify new targets to treat male infertility and have the potential to open new avenues for male contraception.