The impact of copper nanoparticles surfactant on the structural and biological properties of chitosan/sodium alginate wound dressings

Multifunctional wound dressings based on hydrogels are an efficacious and practicable strategy in therapeutic processes and accelerated chronic wound healing. Here, copper (Cu) nanoparticles were added to chitosan/sodium alginate (CS/SA) hydrogels to improve the antibacterial properties of the prepared wound dressings. Due to the super-hydrophobicity of Cu nanoparticles, polyethylene glycol (PEG) was used as a surfactant, and then added to the CS/SA-based hydrogels. The CS/SA/Cu hydrogels were synthesized with 0, 2, 3.5, and 5 wt% Cu nanoparticles. The structural and morphological properties in presence of PEG were evaluated using Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), and field emission scanning electron microscopy (FESEM). The biodegradation and swelling properties of the hydrogels were investigated in phosphate buffer saline (PBS) at 37 °C for up to 30 days. Cell viability and adhesion, as well as antibacterial behavior, were investigated via MTT assay, FESEM, and disk diffusion method, respectively. The obtained results showed that PEG provided new intra- and intermolecular bonds that affected significantly the hydrogels' degradation and swelling ratio, which increased up to ~1200 %. Cell viability reached ~110 % and all samples showed remarkable antibacterial behavior when CS/SA/Cu containing 2 wt% was introduced. This study provided new insights regarding the use of PEG as a surfactant for Cu nanoparticles in CS/SA hydrogel wound dressing, ultimately affecting the chemical bonding and various properties of the prepared hydrogels.

Chitosan-Based Nanoparticles for Targeted Nasal Galantamine Delivery as a Promising Tool in Alzheimer’s Disease Therapy

Natural alkaloid galantamine is widely used for the treatment of mild to moderate Alzheimer’s dementia. Galantamine hydrobromide (GH) is available as fast-release tablets, extended-release capsules, and oral solutions. However, its oral delivery can cause some unwanted side effects, such as gastrointestinal disturbances, nausea, and vomiting. Intranasal administration is one possible way to avoid such unwanted effects. In this work, chitosan-based nanoparticles (NPs) were studied as potential GH delivery vehicles for nasal application. The NPs were synthesized via ionic gelation and studied using dynamic light scattering (DLS) as well as by spectroscopic and thermal methods. The GH-loaded chitosan–alginate complex particles were also prepared as a way to modify the release of GH. The high loading efficiency of the GH was confirmed for both types of particles, at 67% for the GH-loaded chitosan NPs and 70% for the complex chitosan/alginate GH-loaded particles. The mean particle size of the GH-loaded chitosan NPs was about 240 nm, while the sodium alginate coated chitosan particles loaded with GH were expectedly bigger, with a mean particle size of ~286 nm. GH release profiles in PBS at 37 °C were obtained for both types of NPs, and it was found that the GH-loaded chitosan NPs allowed the prolonged release of the incorporated drug for a period of 8 h, while the complex GH-loaded chitosan/alginate NPs released the incorporated GH faster. The stability of the prepared GH-loaded NPs was also demonstrated after 1 year of storage at 5 °C ± 3 °C.

Advances in Antiviral Delivery Systems and Chitosan-Based Polymeric and Nanoparticulate Antivirals and Antiviral Carriers

Current antiviral therapy research is focused on developing dosage forms that enable highly effective drug delivery, providing a selective effect in the organism, lower risk of adverse effects, a lower dose of active pharmaceutical ingredients, and minimal toxicity. In this article, antiviral drugs and the mechanisms of their action are summarized at the beginning as a prerequisite background to develop relevant drug delivery/carrier systems for them, classified and briefly discussed subsequently. Many of the recent studies aim at different types of synthetic, semisynthetic, and natural polymers serving as a favorable matrix for the antiviral drug carrier. Besides a wider view of different antiviral delivery systems, this review focuses on advances in antiviral drug delivery systems based on chitosan (CS) and derivatized CS carriers. CS and its derivatives are evaluated concerning methods of their preparation, their basic characteristics and properties, approaches to the incorporation of an antiviral drug in the CS polymer as well as CS nanoparticulate systems, and their recent biomedical applications in the context of actual antiviral therapy. The degree of development (i.e., research study, in vitro/ex vivo/in vivo preclinical testing), as well as benefits and limitations of CS polymer and CS nanoparticulate drug delivery systems, are reported for particular viral diseases and corresponding antivirotics.

Clonal Diversity and Epidemiological Characteristics of ST239-MRSA Strains

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen associated with severe morbidity and mortality and poses a significant threat to public health worldwide. The genetic diversity based on sequence types of MRSA strains was illustrated in previous studies; meanwhile, the diversity along with the predominant sequence type, especially in Egypt, remains unknown. The purpose of the current study was to determine the diversity of the predominant MRSA clone ST239-MRSA (n = 50) isolated from different hosts and clinical samples and to illustrate the correlation between the resistance patterns, toxin genes, and the genetic background in Port-said and El-Sharkia Governorates, Egypt. The ST239-MRSA clone was analyzed by phenotypic antibiotyping and various genotypic assays comprising SCCmec, agr, spa, coa, and coa-RFLP in addition to toxin gene profiles. Most of the analyzed strains (40/50, 80%) were multidrug resistant (MDR), belonged to SCCmec-III, agr-I, and coa genotype I, and harbored sea and pvl genes. A negative correlation between the toxin gene profiles and antimicrobial resistance was recorded. Meanwhile, the correlation between the toxin gene profiles and the genetic background was not observed in this study. Although ST239-MRSA strains belonged to a single sequence type, they exhibited a high degree of phenotypic and genotypic diversity, indicating weak clonality and adaptability. With such diversity, it is assumed that these strains may have undergone different evolutionary processes during transmission events among and/or within a single host or tissue niche.

Potential Application of Cephalosporins Carried in Organic or Inorganic Nanosystems Against Gram-negative Pathogens

Cephalosporins are β-lactam antibiotics, classified into five generations and extensively used in clinical practice against infections caused by Gram-negative pathogens, including Enterobacteriaceae and P. aeruginosa. Commercially, conventional pharmaceutical forms require high doses to ensure clinical efficacy. Additionally, β-lactam resistance mechanisms, such as the production of enzymes (called extended-spectrum β-lactamases) and the low plasma half-life of these antibiotics have been challenging in clinical therapy based on the use of cephalosporins. In this context, its incorporation into nanoparticles, whether organic or inorganic, is an alternative to temporally and spatially control the drug release and improve its pharmacokinetic and pharmacodynamic limitations. Considering this, the present review unites the cephalosporins encapsulated into organic and inorganic nanoparticles against resistant and nonresistant enterobacteria. We divide cephalosporin generation into subtopics in which we discuss all molecules approved by regulatory agencies. In addition, changes in the side chains at positions R1 and R2 of the central structure of cephalosporins for all semisynthetic derivatives developed were discussed and presented, as the changes in these groups are related to modifications in pharmacological and pharmacokinetic properties, respectively. Ultimately, we exhibit the advances and differences in the release profile and in vitro activity of cephalosporins incorporated in different nanoparticles.

Fabrication of Ceftriaxone-Loaded Cellulose Acetate and Polyvinyl Alcohol Nanofibers and Their Antibacterial Evaluation

Nanotechnology provides solutions by combining the fields of textiles and medicine to prevent infectious microbial spread. Our study aimed to evaluate the antimicrobial activity of nanofiber sheets incorporated with a well-known antibiotic, ceftriaxone. It is a third-generation antibiotic that belongs to the cephalosporin group. Different percentages (0, 5%, 10%, 15%, and 20%; based on polymer wt%) of ceftriaxone were incorporated with a polymer such as polyvinyl alcohol (PVA) via electrospinning to fabricate nanofiber sheets. The Kirby-Bauer method was used to evaluate the antimicrobial susceptibility of the nanofiber sheets using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). For the characterization of the nanofiber sheets incorporated with the drug, several techniques were used, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Our results showed that the nanofiber sheets containing ceftriaxone had potential inhibitory activity against E. coli and S. aureus as they had inhibition zones of approximately 20–25 mm on Mueller-Hinton-agar-containing plates. In conclusion, our nanofiber sheets fabricated with ceftriaxone have potential inhibitory effects against bacteria and can be used as a dressing to treat wounds in hospitals and for other biomedical applications.

Synthesis, Characterization, and Photocatalytic, Bactericidal, and Molecular Docking Analysis of Cu-Fe/TiO2 Photocatalysts: Influence of Metallic Impurities and Calcination Temperature on Charge Recombination

This research evaluated the potential photocatalytic efficiency of synthesized Cu-Fe/TiO2 photocatalysts against organic contaminants and biocontaminants through various synthesis methods (Cu-to-Fe ratio, metal loading, and calcination temperature) and reaction parameters (photocatalyst dose, irradiation time, and different initial methyl orange (MO) concentrations). In addition, the best photocatalysts were characterized through Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), differential reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS) analysis techniques. The best metal loading was 1 wt % with 5:5 Cu/Fe ratio and 300 °C calcination temperature (5Cu-5Fe/TiO2-300) having 97% MO decolorization. Further analysis indicates that the metal presence does not generate new channels for de-excitation but clearly affects the intensity and decreases charge recombination. The behavior of the photoluminescence intensity is (inversely) proportional to the activity behavior through the series, indicating that the main catalytic effect of Fe and Cu relates to charge recombination and that the Cu-Fe bimetallic catalyst optimizes such function. Moreover, the best-engineered photocatalysts asserted impactful bacteriostatic efficacy toward the tested Escherichia coli strain (in 30 min), and therefore, molecular docking studies were used to predict the inhibition pathway against E. coli β-lactamase enzyme. The photocatalyst had a high negative docking score (-5.9 kcal mol-1) due to intense interactions within the active site of the enzyme. The molecular docking study revealed that the ligand could inhibit β-lactamase from producing its bactericidal activity.

Iron-Zinc Co-Doped Titania Nanocomposite: Photocatalytic and Photobiocidal Potential in Combination with Molecular Docking Studies

In the current research study, iron-zinc co-doped TiO2 was reported as an energy efficient material for the degradation of DIPA and inactivation of E. coli and S. aureus under visible light irradiation. In addition, molecular docking simulation was performed to provide further insight into possible targets for inhibiting bacterial development. The synthesized nanocomposites were screened and optimized for different synthesis and reaction parameters. The physicochemical properties of the synthesized nanocomposites were evaluated through different characterization techniques. The wet impregnation (WI) approach was among the most successful methods for the synthesis of Fe-Zn-TiO2 nanocomposite (NC) utilizing anatase titanium. Moreover, 66.5% (60 min reaction time) and 100% (190 min reaction time) chemical oxygen demand (COD) removal was obtained through optimized NC, i.e., 0.1Fe-0.4Zn metal composition and 300 °C calcination temperature. The energy consumption for the best NC was 457.40 KW h m−3. Moreover, 0.1Fe-0.4Zn-TiO2-300 was more efficient against S. aureus compared to E. coli with 100% reduction in 90 min of visible light irradiations. Furthermore, 0.1Fe-0.4Zn-TiO2-300 NC showed that the binding score for best docked conformation was −5.72 kcal mol−1 against β-lactamase from E. coli and −3.46 kcal mol−1 from S. aureus. The studies suggested the Fe-Zn in combination with TiO2 to be a possible inhibitor of β-lactamase that can be further tested in enzyme inhibition studies.

In-vivo toxicity and therapeutic efficacy of Paeonia emodi-mediated zinc oxide nanoparticles: In-vitro study

This study was planned to explore the in-vitro and in-vivo therapeutic significance of Paeonia emodi-mediated zinc oxide nanoparticles (ZnO NPs) against the Staphylococcus aureus and Escherichia coli. The texture parameters were derived from nitrogen adsorption-desorption data using Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods, and the surface area (S_BET ) was found to be 214 m² /g with a pore size of 2.3 nm. The crystallographic parameters were investigated through X-ray diffraction analysis, and the calculated crystallite size is 29.13 nm. The microstructure was examined through transmission and scanning electron microscopies (TEM and SEM, respectively), and the average particle size estimated from a TEM image is 44.40 nm. The chemical composition and attached function groups were identified through energy-dispersive X-ray and Fourier transform infrared spectroscopies. The in-vitro minimum inhibitory concentration (MIC) for both bacterial species results was found less than 2 μg/ml. The tolerance limit of mouse models was evaluated by the inoculation of different concentrations of ZnO suspension where the concentration above 23 ppm was proved lethal. The maximum infection was caused in mouse models by inoculation of 3 × 10⁷ CFUs (Colony forming unit) of the both bacterial species. The concentration higher than 3 × 10⁷ CFUs led to the ultimate death of the mice. The histopathological and hematological studies reveal that the after simultaneous inoculation of both ZnO NPs and bacterial suspensions (tolerated amount), no/negligible infection was found in the mice model.

The contribution of nano-based strategies in overcoming ceftriaxone resistance: a literature review

Antimicrobial drug resistance, including resistance to multiple antibiotics, is continuously increasing. According to research findings, many bacteria resistant to other antibiotics were susceptible to ceftriaxone. However, over the last few years, ceftriaxone resistance has become growing and extremely worrisome challenge to the global healthcare system and several strategies have been initiated to contain the spread of antimicrobial drug resistance. Its extended use for therapeutic or preventative measures in humans and farm animals resulted in the development and spread of resistance. Recent advances in nanotechnology also offer novel formulations based on distinct types of nanostructure particles with different sizes and shapes, and flexible antimicrobial properties. For ceftriaxone, several nanostructured formulations through conjugation, intercalation, encapsulation with lipid carrier, and polymeric films have been investigated by different groups with promising results in combating the development of resistance. This review addressed the existing knowledge and practice on the contribution of nano-based delivery approaches in overcoming ceftriaxone resistance. Evidences have been generated from published research articles using major search electronic databases such as PubMed, Medline, Google Scholar, and Science Direct.

Functionalized Chitosan Nanomaterials: A Jammer for Quorum Sensing

The biggest challenge in the present-day healthcare scenario is the rapid emergence and spread of antimicrobial resistance due to the rampant use of antibiotics in daily therapeutics. Such drug resistance is associated with the enhancement of microbial virulence and the acquisition of the ability to evade the host’s immune response under the shelter of a biofilm. Quorum sensing (QS) is the mechanism by which the microbial colonies in a biofilm modulate and intercept communication without direct interaction. Hence, the eradication of biofilms through hindering this communication will lead to the successful management of drug resistance and may be a novel target for antimicrobial chemotherapy. Chitosan shows microbicidal activities by acting electrostatically with its positively charged amino groups, which interact with anionic moieties on microbial species, causing enhanced membrane permeability and eventual cell death. Therefore, nanoparticles (NPs) prepared with chitosan possess a positive surface charge and mucoadhesive properties that can adhere to microbial mucus membranes and release their drug load in a constant release manner. As the success in therapeutics depends on the targeted delivery of drugs, chitosan nanomaterial, which displays low toxicity, can be safely used for eradicating a biofilm through attenuating the quorum sensing (QS). Since the anti-biofilm potential of chitosan and its nano-derivatives are reported for various microorganisms, these can be used as attractive tools for combating chronic infections and for the preparation of functionalized nanomaterials for different medical devices, such as orthodontic appliances. This mini-review focuses on the mechanism of the downregulation of quorum sensing using functionalized chitosan nanomaterials and the future prospects of its applications.

Zinc oxide nanoparticles conjugated with clinically-approved medicines as potential antibacterial molecules

At present, antibiotic resistance is one of the most pressing issues in healthcare globally. The development of new medicine for clinical applications is significantly less than the emergence of multiple drug-resistant bacteria, thus modification of existing medicines is a useful avenue. Among several approaches, nanomedicine is considered of potential therapeutic value. Herein, we have synthesized Zinc oxide nanoparticles (ZnO-NPs) conjugated with clinically-approved drugs (Quercetin, Ceftriaxone, Ampicillin, Naringin and Amphotericin B) with the aim to evaluate their antibacterial activity against several Gram-positive (Methicillin resistant Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes) and Gram-negative (Escherichia coli K1, Serratia marcescens and Pseudomonas aeruginosa) bacteria. The nanoparticles and their drug conjugates were characterized using UV-visible spectrophotometry, dynamic light scattering, Fourier transform infrared spectroscopy and atomic force microscopy. Antibacterial activity was performed by dilution colony forming unit method and finally 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to determine their cytotoxic effects against human cell lines. ZnO-NPs revealed maxima surface plasmon resonance band at 374 and after conjugation with beta-cyclodextrin at 379 nm, polydispersity with size in range of 25-45 nm with pointed shaped morphology. When conjugated with ZnO-NPs, drug efficacy against MDR bacteria was enhanced significantly. In particular, Ceftriaxone- and Ampicillin-conjugated ZnO-NPs exhibited potent antibacterial effects. Conversely, ZnO-NPs and drugs conjugated NPs showed negligible cytotoxicity against human cell lines except Amphotericin B (57% host cell death) and Amphotericin B-conjugated with ZnO-NPs (37% host cell death). In conclusion, the results revealed that drugs loaded on ZnO-NPs offer a promising approach to combat increasingly resistant bacterial infections.

Nanobiosystems for Antimicrobial Drug-Resistant Infections

The worldwide increased bacterial resistance toward antimicrobial therapeutics has led investigators to search for new therapeutic options. Some of the options currently exploited to treat drug-resistant infections include drug-associated nanosystems. Additionally, the use of bacteriophages alone or in combination with drugs has been recently revisited; some studies utilizing nanosystems for bacteriophage delivery have been already reported. In this review article, we focus on nine pathogens that are the leading antimicrobial drug-resistant organisms, causing difficult-to-treat infections. For each organism, the bacteriophages and nanosystems developed or used in the last 20 years as potential treatments of pathogen-related infections are discussed. Summarizing conclusions and future perspectives related with the potential of such nano-antimicrobials for the treatment of persistent infections are finally highlighted.

Enhanced Antimicrobial and Antibiofilm Effect of New Colistin-Loaded Human Albumin Nanoparticles

Multidrug-resistant (MDR) Gram-negative bacteria (GNB), such as Acinetobacter and Klebsiella, are responsible for severe hospital-acquired infections. Colistin, despite its toxicity and low tissue penetration, is considered the last resort antibiotic against these microorganisms. Of concern, the use of Colistin has recently been compromised by the emergence of Colistin resistance. Herein, we developed a new formulation consisting of multifunctional chitosan-coated human albumin nanoparticles for the delivery of Colistin (Col/haNPs). Col/haNPs were in vitro characterized for encapsulation efficiency, drug release, stability and cytotoxicity and were evaluated for antibacterial activity against MDR GNB (Acinetobacter baumannii and Klebsiella pneumoniae). Col/haNPs showed sizes lower than 200 nm, high encapsulation efficiency (98.65%) and prolonged in vitro release of Colistin. The safety of the nanoformulation was demonstrated by a negligible cytotoxicity on human fibroblasts and hemolytic activity. Col/haNPs evidenced a high antibacterial effect with a significant decrease in MIC values compared to free Colistin, in particular against Col-resistant strains with a pronounced decline of bacterial growth over time. Moreover, Col/haNPs exhibited an inhibitory effect on biofilm formation that was 4 and 60 fold higher compared to free Colistin, respectively for Colistin susceptible and resistant A. baumannii. Our findings suggest that Col/haNPs could represent a promising Colistin nanocarrier with high antimicrobial activity on MDR GNB.

Chitosan Nanoparticles-Insight into Properties, Functionalization and Applications in Drug Delivery and Theranostics

Nanotechnology-based development of drug delivery systems is an attractive area of research in formulation driven R&D laboratories that makes administration of new and complex drugs feasible. It plays a significant role in the design of novel dosage forms by attributing target specific drug delivery, controlled drug release, improved, patient friendly drug regimen and lower side effects. Polysaccharides, especially chitosan, occupy an important place and are widely used in nano drug delivery systems owing to their biocompatibility and biodegradability. This review focuses on chitosan nanoparticles and envisages to provide an insight into the chemistry, properties, drug release mechanisms, preparation techniques and the vast evolving landscape of diverse applications across disease categories leading to development of better therapeutics and superior clinical outcomes. It summarizes recent advancement in the development and utility of functionalized chitosan in anticancer therapeutics, cancer immunotherapy, theranostics and multistage delivery systems.

Nanomedicine: a new paradigm to overcome drug incompatibilities

OBJECTIVES

Drug incompatibilities may compromise the safety and effectiveness of combined drugs and result in mild-to-serious clinical complications, such as catheter obstruction, loss of drug efficacy, formation of toxic derivatives and embolism. Various preventive strategies have been implemented to overcome drug incompatibilities with limited success. This review presents an innovative approach to prevent drug incompatibilities via isolating the incompatible drugs into nanostructures.

KEY FINDINGS

Several examples of incompatible drugs may be loaded separately into nanostructures of various types. Physicochemical characteristics and biocompatibility of the nanomaterials that are being utilized to prevent physicochemical incompatibilities should be carefully considered.

CONCLUSIONS

There is a new era of exploiting nanomaterials in overcoming various types of physicochemical incompatibilities, with additional benefits of further improvements in pharmacokinetic profiles and pharmacological actions of the administered drugs.

Physico-Chemically Distinct Nanomaterials Synthesized from Derivates of a Poly(Anhydride) Diversify the Spectrum of Loadable Antibiotics

Recent advances in the field of nanotechnology such as nanoencapsulation offer new biomedical applications, potentially increasing the scope and efficacy of therapeutic drug delivery. In addition, the discovery and development of novel biocompatible polymers increases the versatility of these encapsulating nanostructures, enabling chemical properties of the cargo and vehicle to be adapted to specific physiological requirements. Here, we evaluate the capacity of various polymeric nanostructures to encapsulate various antibiotics of different classes, with differing chemical structure. Polymers were sourced from two separate derivatives of poly(methyl vinyl ether-alt-maleic anhydride) (PMVE/MA): an acid (PMVE/MA-Ac) and a monoethyl ester (PMVE/MA-Es). Nanoencapsulation of antibiotics was attempted through electrospinning, and nanoparticle synthesis through solvent displacement, for both polymers. Solvent incompatibilities prevented the nanoencapsulation of amikacin, neomycin and ciprofloxacin in PMVE/MA-Es nanofibers. However, all compounds were successfully loaded into PMVE/MA-Es nanoparticles. Encapsulation efficiencies in nanofibers reached approximately 100% in all compatible systems; however, efficiencies varied substantially in nanoparticles systems, depending on the tested compound (14%-69%). Finally, it was confirmed that both these encapsulation processes did not alter the antimicrobial activity of any tested antibiotic against Staphylococcus aureus and Escherichia coli, supporting the viability of these approaches for nanoscale delivery of antibiotics.

Fabrication of biopolymer polyhydroxyalkanoate/chitosan and 2D molybdenum disulfide-doped scaffolds for antibacterial and biomedical applications

Antibiotic resistance in pathogenic bacteria is a major health challenge, as Infectious Diseases Society of America (IDSA) has recognized that the past simply drugs susceptible pathogens are now the most dangerous pathogens due to their nonstop growing resistance towards conventional antibiotics. Therefore, due to the emergence of multi-drug resistance, the bacterial infections have become a serious global problem. Acute infections feasibly develop into chronic infections because of many factors; one of them is the failure of effectiveness of antibiotics against superbugs. Modern research of two-dimensional nanoparticles and biopolymers are of great interest to attain the intricate bactericidal activity. In this study, we fabricated an antibacterial nanocomposite consisting of representative two-dimensional molybdenum disulfide (2D MoS₂) nanoparticles. Polyhydroxyalkanoate (PHA) and chitosan (Ch) are used to encapsulate MoS₂ nanoparticles into their matrix. This study reports the in vitro antibacterial activity and host cytotoxicity of novel PHA-Ch/MoS₂ nanocomposites. PHA-Ch/MoS₂ nanocomposites were subjected to time-dependent antibacterial assays at various doses to examine their antibacterial activity against multi-drug-resistant Escherichia coli K1 (Malaysian Type Culture Collection 710859) and methicillin-resistant Staphylococcus aureus (MRSA) (Malaysian Type Culture Collection 381123). Furthermore, the cytotoxicity of nanocomposites was examined against spontaneously immortalized human keratinocyte (HaCaT) cell lines. The results indicated significant antibacterial activity (p value < 0.05) against E. coli K1 and MRSA. In addition, PHA-Ch/MoS₂ showed significant host cytocompatibility (p < 0.05) against HaCaT cells. The fabricated PHA-Ch/MoS₂ nanocomposites have demonstrated effective antibacterial activity against both Gram-positive and -negative bacteria and exhibited better biocompatibility. Finally, PHA-Ch/MoS₂ nanocomposites are shown to be suitable for antibacterial applications and also hold potential for further biomedical studies. Graphical Abstract.

The synthesis, characterization and applications of poly[N-isopropylacrylamide-co-3-allyloxy-1,2-propanediol] grafted onto modified magnetic nanoparticles

In this paper, a novel method is investigated for the extraction, determination, and delivery of ceftazidime in simulated gastric and real biological fluids such as serum plasma and urine in in vitro drug delivery systems.

Appliance of fungal chitosan/ceftriaxone nano-composite to strengthen and sustain their antimicrobial potentiality against drug resistant bacteria

Nano-biopolymers could be employed for the delivery of active compounds to increase their stability, bioavailability, efficacy and sustainability. The bioactive chitosan polymer (Cts) was extracted from grown fungus, Cunninghamella elegans, and used for loading ceftriaxone (CFT) and forming the nano-conjugates using tripolyphosphate (TPP) - ionic crosslinking method. The characterization of synthesized CFT/chitosan nanoparticles (NCT) revealed that they chemically crosslinked and had particles' size mean of 56 nm. The CFT loading capacity onto NCT was 54.37%, while its entrapment efficiency was apparently high (79.43%); the maximum released of CFT was 78% from NCT composite after 90 h from dialysis. The CFT/NCT antibacterial activity was confirmed against 3 strains of Staphylococcus aureus (methicillin resistants), using disc diffusion and scanning images of electron microscope, which elucidate that CFT/NCT nano-composite had a vigorous action toward bacterial cells; most cells were ruptured and exploded after 6 h of exposure and entirely lysed after 9 h. The formulation of CFT/NCT nano-composite is exceedingly recommended for enhancing drug biocidal activity, especially against resistant bacterial strains.

Emerging Nanomedicine Therapies to Counter the Rise of Methicillin-Resistant Staphylococcus aureus

In a recent report, the World Health Organisation (WHO) classified antibiotic resistance as one of the greatest threats to global health, food security, and development. Methicillin-resistant Staphylococcus aureus (MRSA) remains at the core of this threat, with persistent and resilient strains detectable in up to 90% of S. aureus infections. Unfortunately, there is a lack of novel antibiotics reaching the clinic to address the significant morbidity and mortality that MRSA is responsible for. Recently, nanomedicine strategies have emerged as a promising therapy to combat the rise of MRSA. However, these approaches have been wide-ranging in design, with few attempts to compare studies across scientific and clinical disciplines. This review seeks to reconcile this discrepancy in the literature, with specific focus on the mechanisms of MRSA infection and how they can be exploited by bioactive molecules that are delivered by nanomedicines, in addition to utilisation of the nanomaterials themselves as antibacterial agents. Finally, we discuss targeting MRSA biofilms using nano-patterning technologies and comment on future opportunities and challenges for MRSA treatment using nanomedicine.