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Background: Magnolol (MG) and honokiol (HK) are bioactive compounds extracted from Magnolia obovata and Magnolia Officinalis trees with significant pharmacological properties, including antioxidant and antibacterial activity. However, their poor water solubility and low bioavailability limit the therapeutic potential. Methods: To address these limitations, this study aims to develop MG and HK formulations by co-electrospinning using custom-synthesized β-cyclodextrin-oligolactide (β-CDLA) derivatives. MALDI MS and NMR were employed for the structural assessment of the β-CDLA derivatives. This polymer-free electrospinning technique utilizes the high solubility of β-CDLA to incorporate MG and HK into fibrous webs. The morphology of the resulting fibers is established by SEM and further characterized using FTIR and NMR spectroscopy to confirm the successful incorporation of MG and HK. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, while the antimicrobial activity was evaluated against several standard microorganisms ( Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , and Candida albicans ). Results: The MG and HK electrospun formulations were prepared using highly concentrated feed solutions in dimethylformamide (180% w/v). The resulting β-CDLA fibers, with diameters above 400 nm and an active compound content of 7% wt., exhibited enhanced long-term antioxidant activity and improved antimicrobial efficacy, including notable activity against Escherichia coli . Conclusions: This study demonstrates the potential of MG and HK-loaded β-CDLA fibrous formulations as delivery systems with prolonged antioxidant activity and notable antibacterial efficacy, providing a promising platform for biomedical applications.

New quaternary ammonium derivatives (quats) based on apple pectin (PA) were synthesized by the chemical modification of native polysaccharides with various quaternization mixtures containing epichlorohydrin (ECH) and a tertiary amine. Pectin derivatives (QPAs) were studied by elemental analysis, conductometric titration, Fourier-transform infrared spectroscopy (FTIR), and 13 C nuclear magnetic resonance ( 13 C NMR). Viscosity measurements enabled the evaluation of the viscosity average molar mass (M v ) for the unmodified polysaccharide, as well as its intrinsic viscosity ([η]) value. Dynamic light scattering (DLS) analysis revealed that the PA and its quats formed aggregates in an aqueous solution with either a unimodal (PA) or bimodal (QPAs) distribution. Scanning transmission electron microscopy analysis (STEM) of the PA and its derivatives demonstrated the presence of individual polymeric chains and aggregates in aqueous solution, with the smallest sizes being specific to amphiphilic polymers. Thermal stability, as well as wide-angle X-ray diffraction (WAXD) studies, generally indicated a lower thermal stability and crystallinity of the QPAs compared with those of the PA. Antipathogenic activity demonstrated that the PA and its derivatives exhibited effectiveness against S. aureus ATCC 25923 bacterium and C. albicans ATCC 10231 pathogenic yeast.

New citrus pectin derivatives carrying pendant N , N -dimethyl- N -alkyl- N -(2-hydroxy propyl) ammonium chloride groups were achieved via polysaccharide derivatization with a mixture of N , N -dimethyl- N -alkyl amine (alkyl = ethyl, butyl, benzyl, octyl, dodecyl) and epichlorohydrin in aqueous solution. The structural characteristics of the polymers were examined via elemental analysis, conductometric titration, Fourier Transform Infrared spectroscopy (FTIR) and 1D ( 1 H and 13 C) nuclear magnetic resonance (NMR). Capillary viscosity measurements allowed for the study of viscometric behavior as well as the determination of viscosity-average molar mass for pristine polysaccharide and intrinsic viscosity ([η]) values for pectin and its derivatives. Dynamic light scattering measurements (DLS) showed that pectin-based polymers formed aggregates in aqueous solution with a unimodal distribution. Critical aggregation concentration ( cac ) for the hydrophobic pectin derivatives were determined using fluorescence spectroscopy. Atom force microscopy (AFM) images allowed for the investigation of the morphology of polymeric populations obtained in aqueous solution, consisting of flocs and aggregates for crude pectin and its hydrophilic derivatives and well-organized aggregates for lipophilic pectin derivatives. Antimicrobial activity, examined using the disc diffusion method, proved that all polymers were active against Staphylococcus aureus bacterium and Candida albicans yeast.

Natural deep eutectic solvents (NADES)-hydroxypropyl cellulose (HPC) self-assembled gels with potential for pharmaceutical applications are prepared. FT-IR, 1HNMR, DSC, TGA and rheology measurements revealed that hydrogen bond acceptor−hydrogen bond donor interactions, concentration of NADES and the water content influence significantly the physico-chemical characteristics of the studied gel systems. HPC-NADES gel compositions have thermal stabilities lower than HPC and higher than NADES components. Thermal transitions reveal multiple glass transitions characteristic of phase separated systems. Flow curves evidence shear thinning (pseudoplastic) behavior. The flow curve shear stress vs. shear rate were assessed by applying Bingham, Herschel−Bulkley, Vocadlo and Casson rheological models. The proposed correlations are in good agreement with experimental data. The studied gels evidence thermothickening behavior due to characteristic LCST (lower critical solution temperature) behavior of HPC in aqueous systems and a good biocompatibility with normal cells (human gingival fibroblasts). The order of antibacterial and antifungal activities (S.aureus, E.coli, P. aeruginosa and C. albicans) is as follows: citric acid >lactic acid > urea > glycerol, revealing the higher antibacterial and antifungal activities of acids.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to a global health outbreak known as the COVID-19 pandemic which has been lasting since March 2020. Vaccine became accessible to people only at the beginning of 2021 which greatly helped reducing the mortality rate and severity of COVID-19 infection afterwards. The efficacy of vaccines was not fully known and studies documenting the immune responses following vaccination are continuing to emerge. Recent evidence indicate that natural infection prior vaccination may improve the antibody and cellular immune responses, while little is known about the factors influencing those processes. Here we investigated the antibody responses following BNT162b2 vaccination in relation to previous-infection status and age, and searched for possible biomarkers associated with the observed changes in immune responses. We found that the previous-infection status caused at least 8-times increase in the antibody titres, effect that was weaker in people over 60 years old and unaltered by the vitamin D serum levels. Furthermore, we identified adiponectin to positively associate with antibody responses and negatively correlate with pro-inflammatory molecules (MCP-1, factor D, CRP, PAI-1), especially in previously-infected individuals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Pavel-Tanasa, Constantinescu, Cianga, Anisie, Mereuta, Tuchilus and Cianga.)

The intricate relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the cardiovascular system is an extensively studied pandemic topic, as there is an ever-increasing amount of evidence that reports a high prevalence of acute cardiac injury in the context of viral infection. In patients with Coronavirus disease 2019, COVID-19, a significant increase in serum levels of cardiac troponin or other various biomarkers was observed, suggesting acute cardiac injury, thus predicting both a severe course of the disease and a poor outcome. Pathogenesis of acute cardiac injury is not yet completely elucidated, though several mechanisms are allegedly involved, such as a direct cardiomyocyte injury, oxygen supply-demand inequity caused by hypoxia, several active myocardial depressant factors during sepsis, and endothelial dysfunction due to the hyperinflammatory status. Moreover, the increased levels of plasma cytokines and catecholamines and a significantly enhanced prothrombotic environment may lead to the destabilization and rupture of atheroma plaques, subsequently triggering an acute coronary syndrome. In the present review, we focus on describing the epidemiology, pathogenesis, and role of biomarkers in the diagnosis and prognosis of patients with acute cardiac injury in the setting of the COVID-19 pandemic. We also explore some novel therapeutic strategies involving immunomodulatory therapy, as well as their role in preventing a severe form of the disease, with both the short-term outcome and the long-term cardiovascular sequelae being equally important in patients with SARS-CoV-2 induced acute cardiac injury.

Allantoin and its β-cyclodextrin and hydroxypropyl-β-cyclodextrin inclusion complexes 1:1 have been used to prepare carbopol-based mucoadhesive gels. The gelation process occurred by adjustment with glycerol 10% in the presence of triethanolamine. The structural features induced by the presence of allantoin and the corresponding β-cyclodextrins inclusion complexes have been first investigated by infrared spectroscopy highlighting strong interactions within the gels network and ideal crosslinks for the self-healing behavior. The hydrophilicity of the gels was investigated by the determination of the surface tension parameters and the free energy of hydration. The interfacial free energy values indicated prolonged biocompatibility with blood. The gels-water molecule interactions in terms of sorption, permeability, and diffusion coefficients were evaluated by dynamic vapor sorption analysis. The self-assembly process through intermolecular H-bonding, the high hydrophilicity, the mechanical performance, the hydrolytic stability in simulated biological media, the biocompatibility with normal human dermal fibroblast (NHDF) cells, the mucoadhesivity and antimicrobial activity on selected microorganism species ( S. Aureus and C. albicans ) of the allantoin-based gels recommend them as promising scaffold alternatives in regenerative medicine.

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

New amphiphilic dextran esters were obtained by polysaccharide functionalization with different substituted 1,2,3-triazoles-4-carboxylic acid via in situ activation with N, N'-carbonyldiimidazole. Nitrogen-containing heterocyclic derivatives were achieved by copper(I)-catalyzed cycloaddition reaction between organic azides and ethyl propiolate. Structural characteristics of the compounds were studied by elemental analysis, Fourier transform infrared and nuclear magnetic resonance spectroscopy ( 1 H and 13 C-NMR). Thermogravimetric analysis, differential scanning calorimetry and wide-angle X-ray diffraction were used for esters characterization. Properties of polymeric self-associates, formed in aqueous solution, were studied by dynamic light scattering and transmission electron microscopy. The critical aggregation concentration values for dextran esters, determined by fluorescence spectroscopy, were in the range of 4.1-9.5 mg/dL. Antimicrobial activity, investigated for some of the polymers by disc-diffusion method, pointed out that polysaccharide esters were active., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: Aim of this work was preparation of bioadhesive gel formulations based on Hydroxypropyl methylcellulose (HPMC), Poly(acrylic acid) (PAA) or Sodium alginate (SA) loaded with anise/fluconazole β-cyclodextrin inclusion complexes in 1:2 and 1:3 ratios intended for vaginal applications., Methods: Freeze-drying method was effectively utilized and superporous morphology was obtained. The superporous morphology of the lyophilized gels, dynamic water vapor sorption measurements, drug release kinetics studies and their antimicrobial activities are presented., Results: HPMC content influences especially the sorption/desorption behaviour of HPMC-based PAA gels and the morphology of the gel formulations with fluconazole/β-cyclodextrin inclusion complexes, due to the interactions among the gel networks absorbing water molecules. It was found that fluconazole release kinetics correspond to quasi-Fickian, Fickian diffusion and non-Fickian mechanisms for the studied hydrogels. The tested vaginal formulations with β-cyclodextrin inclusion complexes exhibited selectivity toward S. aureus ATCC 25923 and all tested Candida strains in comparison with the gel formulation without β-cyclodextrin., Conclusions: The fluconazole/β cyclodextrin inclusion complexes ensure a controlled release of fluconazole over a few days, the highest amount of drug release (92%) being observed after 43 h. These bioadhesive gel formulations could be very promising topical alternative for treatment of vaginal fungal infections.

Cationic amphiphilic dextran derivatives with a long alkyl group attached to the reductive end of the polysaccharide chain and quaternary ammonium groups attached as pendent groups to the main dextran backbone were synthesized and tested for their antimicrobial properties against several bacteria and fungi strains. Dependence of antimicrobial activity on both polymer chemical composition (dextran molar mass, length of end alkyl group and chemical structure of ammonium groups) and type of microbes was highlighted by disc-diffusion method (diameter of inhibition zone) and broth microdilution method (minimum inhibitory concentrations). Polymers had antimicrobial activity for all strains studied, except for Pseudomonas aeruginosa ATCC 27853. The best activity against Staphylococcus aureus (Minimun Inhibitory Concentration 60μg/mL) was provided by polymers obtained from dextran with lower molecular mass (Mn=4500), C 12 H 25 or C 18 H 37 end groups, and N,N-dimethyl-N-benzylammonium pendent groups., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Polyurethane/β-cyclodextrin/ciprofloxacin composite films have been prepared and structural and morphological behaviours reveal the progressive incorporation of the drug ciprofloxacin into polyurethane backbones. Spectral changes such as frequency shifts, band broadening and changes in the intensity are indicative of drug-polyurethane interactions. X-ray powder diffraction experiments demonstrate that ciprofloxacin retains its crystallinity in the polyurethane matrix. Electron microscopy and mercury porosimetry reveal open and interconnected macroporous pore morphology for the as-prepared polyurethane-drug films. Antimicrobial activity was evaluated by the agar disc diffusion method and the ciprofloxacin-polyurethane films demonstrate their potency as antibacterial medical systems. However, the ciprofloxacin-polyurethane films do not reveal antifungal properties.