Chemical Analysis of Selected Seaweeds and Seagrass from the Adriatic Coast of Montenegro.

Three seaweeds (Halimeda tuna, Codium bursa and Cystoseira barbata) and one seagrass (Cymodocea nodosa) were collected from the Coast of Montenegro, Gulf of Boka Kotorska and their chemical analysis was performed. In seagrass C. nodosa, three phenolic compounds were identified (diosmetin 7-sulfate, caftaric and coutaric acid). The content of ß-glucan, fatty acids, sterols and micro- and macro-elements were investigated among all samples. The highest content of ß-glucan was detected in C. nodosa seagrass (13.04±0.42 g/100 g). The highest polyunsaturated fatty acids (PUFAs) level was reported in C. barbata, the brown alga (7.157 mg/g), which also had the significant sterol content (fucosterol, 21.76±0.1 µg/g). Green algae, C. bursa and H. tuna, showed the highest level of sterols (ß-sitosterol, 95.21±0.16 µg/g and 73.90±0.08 µg/g, respectively). H. tuna had the highest content of calcium (Ca) in amount of 55125 µg/g. In C. bursa, C. barbata and C. nodosa, the Na/K ratio was low (0.43, 0.46 and 0.69, respectively).

The effect of complexation with cyclodextrins on the antioxidant and antimicrobial activity of ellagic acid.

PURPOSE: The aim of the paper was to develop the simple procedures for preparation of inclusion complexes of ellagic acid (EA) with cyclodextrins (CDs) and to investigate their antioxidant and antimicrobial activity. METHODS: The structural characterization was carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) methods. The phase solubility technique was used to investigate the interactions between 'host' and 'guest' molecules and to estimate the molar ratio between them. The antioxidant and antimicrobial activity of EA and inclusion complexes were determined. RESULTS: The apparent stability constants were found to be 117 dm3 mol-1 for the complex with ß-CD and 161 dm3 mol-1 for the complex with (2-hydroxypropyl)-ß-cyclodextrin (HP-ß-CD). The results of phase-solubility studies showed that EA formed the inclusion complexes with CDs in the molar ratio of 1:1. The calculated half-maximal inhibitory concentration was 41.18 µg cm-3 for butyl hydroxy toluene, 1.96 µg cm-3 for EA, 0.88 µg cm-3 for inclusion complex with HP-ß-CD, and 1.27 µg cm-3 for inclusion complex with ß-CD. CONCLUSION: The stability constants indicated the rapid release of EA from the inclusion complexes in the aqueous medium at 25 °C. The antioxidant activity of EA was increased, while the antimicrobial activity was preserved after complexation with CDs.

Is it possible to improve prognostic value of NCCN-IPI in patients with diffuse large B cell lymphoma? The prognostic significance of comorbidities.

The prognostic value of the International Prognostic Index (IPI) has been re-evaluated in the rituximab-treated diffuse large B cell lymphoma (DLBCL) patients. Accordingly, National Comprehensive Cancer Network-IPI (NCCN-IPI) has been introduced to estimate prognosis of DLBCL patients. However, comorbidities that frequently affect elderly DLBCL patients were not analyzed. The aim of this study was to evaluate the prognostic significance of comorbidities using Charlson Comorbidity Index (CCI) in 962 DLBCL patients. According to CCI, majority of patients (73.6%) did not have any comorbidity, while high CCI (≥ 2) was observed in 71/962 (7.4%) patients, and in 55/426 (12.9%) of the elderly patients aged ≥ 60 years. When the CCI was analyzed in a multivariate model along with the NCCN-IPI parameters, it stood out as a threefold independent risk factor of a lethal outcome. Also, we have developed a novel comorbidity-NCCN-IPI (cNCCN-IPI) by adding additional 3 points if the patient had a CCI ≥ 2. Four risk groups emerged with the following patient distribution in low, low-intermediate, high-intermediate, and high group: 3.4, 34.3, 49.4, and 12.5%, respectively. The prognostic value of the new cNCCN-IPI was 2.1% improved compared to that of the IPI, and 1.3% improved compared to that of the NCCN-IPI (p < 0.05). This difference was more pronounced in elderly patients, in whom the cNCCN-IPI showed a 5.1% better discriminative power compared to that of the IPI, and 3.6% better compared to the NCCN-IPI. The NCCN-IPI enhanced by the CCI and combined with redistributed risk groups is better for differentiating risk categories in unselected DLBCL patients, especially in the elderly.

Broad-spectrum of antimicrobial properties of commercial wines from different Vitis vinifera L. varieties.

Fifteen commercial wines produced from international and autochthonic varieties of Vitis vinifera L. cultivation of different Balkan winegrowing subregions were studied for their antimicrobial activity against six Gram-positive (Clostridium perfringens, Bacillus subtilis, Staphylococcus aureus, Listeria inocua, Sarcina lutea and Micrococcus flavus) and six Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Shigella sonnei, Klebsiella pneumonia and Proteus vulgaris) bacteria. The concentrations and types of phenolic compounds responsible for antibacterial activity in wines were investigated by HPLC and spectroscopic methods. The correlation between amounts of phenolics and antibacterial activities of investigated wines were studied by application of statistical (PCA, factor and cluster) analyses. This study gives the possibility to predict the biological quality of the wine from the same cluster towards bacteria without "wet" analysis. Obtained results can to be useful both to wine producers for the formation of market price of wine, and to wine consumers in choosing quality red wine with high content of polyphenols.

Sulfanilamide in solution and liposome vesicles; in vitro release and UV-stability studies.

The main goal of this study was to develop a liposome formulation with sulfanilamide and to investigate the liposomes impact on its release and stability to the UV-A/UV-B and UV-C irradiation. Liposome dispersions with incorporated sulfanilamide were prepared by thin-film hydration method and liposomes role to the sulfanilamide release was investigated by using a dialysis method. Comparatively, sulfanilamide in phosphate buffer solution was subject to release study as well to the UV irradiation providing for the possibilities of kinetics analysis. In vitro drug release study demonstrated that 20% of sulfanilamide was released from liposomes within 1 h that is approximately twice as slower as in the case of dissolved sulfanilamide in phosphate buffer solution. The kinetic release process can be described by Korsmeyer-Peppas model and according to the value of diffusion release exponent it can be concluded that drug release mechanism is based on the phenomenon of diffusion. The sulfanilamide degradation in phosphate buffer solution and liposomes is related to the formation of UV-induced degradation products that are identified by UHPLC/MS analysis as: sulfanilic acid, aniline and benzidine. The UV-induced sulfanilamide degradation in the phosphate buffer solution and liposome vesicles fits the first- order kinetic model. The degradation rate constants are dependent on the involved UV photons energy input as well as sulfanilamide microenvironment. Liposome microenvironment provides better irradiation sulfanilamide stability. The obtained results suggest that liposomes might be promising carriers for delayed sulfanilamide delivery and may serve as a basis for further research.

Comparative Study of the Biological Activity of Allantoin and Aqueous Extract of the Comfrey Root.

This study investigates the biological activity of pure allantoin (PA) and aqueous extract of the comfrey (Symphytum officinale L.) root (AECR) standardized to the allantoin content. Cell viability and proliferation of epithelial (MDCK) and fibroblastic (L929) cell line were studied by using MTT test. Anti-irritant potential was determined by measuring electrical capacitance, erythema index (EI) and transepidermal water loss of artificially irritated skin of young healthy volunteers, 3 and 7 days after application of creams and gels with PA or AECR. Pure allantoin showed mild inhibitory effect on proliferation of both cell lines at concentrations 40 and 100 µg/ml, but more pronounced on MDCK cells. Aqueous extract of the comfrey root effect on cell proliferation in concentrations higher than 40 µg/ml was significantly stimulatory for L929 but inhibitory for MDCK cells. Pharmaceutical preparations that contained AECR showed better anti-irritant potential compared with PA. Creams showed better effect on hydration and EI compared with the gels that contained the same components. Our results indicate that the biological activity of the comfrey root extract cannot be attributed only to allantoin but is also likely the result of the interaction of different compounds present in AECR. Topical preparations that contain comfrey extract may have a great application in the treatment of skin irritation.

Kinetics of NiO and NiCl2 hydrogen reduction as precursors and properties of produced Ni/Al2O3 and Ni-Pd/Al2O3 catalysts.

The objects of this investigation were the comparative kinetic analysis of the NiO and NiCl2 reduction by hydrogen during an induction period and elimination of the calcination during the synthesis of Ni/Al2O3 catalysts. The effect of temperature and time on NiO and NiCl2 reduction degrees was studied. Avrami I equation was selected as the most favorable kinetic model and used to determine activation energy of the NiO and NiCl2 reduction for the investigated temperature range (623-923 K) and time intervals (1-5 minutes). The investigation enabled reaching conclusions about the reaction ability and rate of the reduction processes. Afterward, Ni/Al2O3 catalysts were obtained by using oxide and chloride precursor for Ni. The catalysts were supported on alumina-based foam and prepared via aerosol route. Properties of the samples before and after low-temperature hydrogen reduction (633 K) were compared. Obtained results indicated that the synthesis of Ni/Al2O3 catalysts can be more efficient if chloride precursor for Ni is directly reduced by hydrogen during the synthesis process, without the calcination step. In addition, Ni-Pd/Al2O3 catalysts with different metal content were prepared by using chloride precursors. Lower reduction temperature was utilized and the chlorides were almost completely reduced at 533 K.

Biological evaluation of synthesized allicin and its transformation products obtained by microwaves in methanol: antioxidant activity and effect on cell growth.

Allicin is the most biologically active substance present in garlic. It can be synthesized or obtained by extraction of fresh garlic. Transformation products of allicin are also biologically active. The aim of this study was to examine the antioxidant activity of synthesized allicin and its transformation products obtained using microwaves in methanol at 55 °C as well as their effect on HeLa cells growth. The antioxidant activity was determined by DPPH (2,2-diphenyl-1-picrylhydrazyl radical) test. The effect on HeLa cells growth was determined by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) test. For MTT test, allicin and its transformation products were dispersed in carmellose sodium solution and examined in concentrations ranging from 0.3 µg/mL to 3 mg/mL. Allicin showed stronger antioxidant activity than the transformation products. A maximum degree of neutralization of DPPH radicals, about 90%, was reached when the concentration of allicin was 2 mg/mL, with an EC50 (concentration of sample which is required for reduction of the initial concentration DPPH radicals to 50%) value of 0.37 mg/mL. In our study, allicin and its transformation products were not cytotoxic to HeLa cells under the examined conditions. The highest concentration of allicin and its transformation products had a slight antiproliferative effect, with a more pronounced effect of allicin, which reflected on the morphology of HeLa cells. The examined substances are safe to use on epithelial cells at concentrations up to 3 mg/mL when applied in carmellose sodium solution. Using carmellose sodium as a dispersing agent could be recommended as a good approach for testing liposoluble substances in liquid cell cultures.

Occupational safety knowledge management in Slovenia, Croatia and Serbia.

This article elaborates the characteristics of knowledge management in the context of occupational safety and presents the results of research based on the assumption that there is a link between knowledge management and occupational safety performance, and that knowledge management can help in improving occupational safety performance. The research involved 645 occupational safety experts from three Balkan countries (Slovenia, Croatia and Serbia). The results showed that the knowledge management in the organization is related to all of the observed aspects of occupational safety performance: number of work-related injuries within the organization; number of lost working days due to injuries; costs caused by work-related injuries and occupational diseases; financial investments in occupational safety; assessment of the state of occupational safety. The practical implications of the article can be seen in the context of meeting the educational needs for continuous learning and improvement of knowledge/lifelong learning in the field of occupational safety.

Modified Sulfanilamide Release from Intelligent Poly(N-isopropylacrylamide) Hydrogels.

The aim of this study was to examine homopolymeric poly(N-isopropylacrylamide), p(NIPAM), hydrogels cross-linked with ethylene glycol dimethacrylate as carriers for sulfanilamide. Using FTIR, XRD and SEM methods, structural characterization of synthesized hydrogels before and after sulfanilamide incorporation was performed. The residual reactants content was analyzed using the HPLC method. The swelling behavior of p(NIPAM) hydrogels of different crosslinking degrees was monitored in relation to the temperature and pH values of the surrounding medium. The effect of temperature, pH, and crosslinker content on the sulfanilamide release from hydrogels was also examined. The results of the FTIR, XRD, and SEM analysis showed that sulfanilamide is incorporated into the p(NIPAM) hydrogels. The swelling of p(NIPAM) hydrogels depended on the temperature and crosslinker content while pH had no significant effect. The sulfanilamide loading efficiency increased with increasing hydrogel crosslinking degree, ranging from 87.36% to 95.29%. The sulfanilamide release from hydrogels was consistent with the swelling results-the increase of crosslinker content reduced the amount of released sulfanilamide. After 24 h, 73.3-93.5% of incorporated sulfanilamide was released from the hydrogels. Considering the thermosensitivity of hydrogels, volume phase transition temperature close to the physiological temperature, and the satisfactory results achieved for sulfanilamide incorporation and release, it can be concluded that p(NIPAM) based hydrogels are promising carriers for sulfanilamide.

Biomedical Applications of Thermosensitive Hydrogels for Controlled/Modulated Piroxicam Delivery.

The objectives of this study are the synthesis of thermosensitive poly(N-isopropylacrylamide-co-2-hydroxypropyl methacrylate), p(NiPAm-HPMet), hydrogels and the analysis of a drug-delivery system based on piroxicam, as a model drug, and synthesized hydrogels. A high pressure liquid chromatography method has been used in order to determine both qualitative and quantitative amounts of unreacted monomers and crosslinkers from polymerized hydrogels. Swelling kinetics and the order of a swelling process of the hydrogels have been analyzed at 10 and 40 °C. The copolymers' thermal properties have been monitored by the differential scanning calorimetry (DSC) method. DSC termograms have shown that melting occurs in two temperature intervals (142.36-150.72 °C and 153.14-156.49 °C). A matrix system with incorporated piroxicam has been analyzed by using FTIR and SEM methods. Structural analysis has demonstrated that intermolecular non-covalent interactions have been built between side-groups of copolymer and loaded piroxicam. Morphology of p(NiPAm-HPMet) after drug incorporation indicates the piroxicam presence into the copolymer pores. Kinetic parameters of the piroxicam release from hydrogels at 37 °C and pH 7.4 indicate that the fluid transport mechanism corresponds to Fickian diffusion. As a result, formulation of thermosensitive p(NiPAm-HPMet) hydrogels with incorporated piroxicam could be of interest for further testing as a drug carrier for modulated and prolonged release, especially for topical administration.

Osage orange (Maclura pomifera (Raf.) Schneid) fruit extracts: UHPLC-DAD-ESI-MS/MS analysis, antioxidant activity and in vivo skin tests.

This work aimed to evaluate chemical profile, antioxidant activity and topical application safety of the raw Osage orange (Maclura pomifera (Raf.) Schneid) fruit extracts obtained by maceration using ethanol and acetone. Out of eighteen different compounds registered in the extracts, fifteen were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry. Pomiferin and osajin were characteristic and representative compounds in both ethanolic and acetone extracts of the Osage orange fruit. Both extracts showed good antioxidant activity (EC50 = 0.03 mg/cm3) after 20 min of incubation. The topical administration safety of the extracts was evaluated in vivo by measuring skin biophysical parameters: electrical capacitance and erythema index, as indicators of stratum corneum hydration and irritation, respectively. Based on the results of the in vivo skin tests, it can be concluded that both of the Osage orange fruit extracts are safe for topical administration - they increased skin hydration and reduced skin irritation under the occlusion.

Temperature-Sensitive Hydrogels as Carriers for Modulated Delivery of Acetaminophen.

The purposes of this study are the polymerization of temperature-sensitive copolymers based on N-isopropyl acrylamide and 10 mol % of 2-hydroxypropylmethacrylate, characterisations of their thermal, morphological and swelling properties, as well as the analysis of potential application in drug-delivery systems. Acetaminophen, the representative of non-steroidal anti-inflammatory drugs, was used as a model drug in this study. It is a common pain relief drug, which is also used for fever treatment. However, oral administration comes with certain health risks, mainly the overdose and frequent administration of up to four times a day. The goal of applying temperature-sensitive hydrogel is to enable extended administration once a day, depending on the body temperature. The swelling behavior of the obtained poly(N-isopropyl acrylamide-co-2-hydroxypropylmethacrylate) (p(NIPA/HPMA)) hydrogels and their temperature-sensitivity, kinetics and order of swelling processes at 18 and 38 °C were analyzed. The thermal properties of these hydrogels were observed by the DSC method, and the obtained thermograms showed both melting and glass transitions. The drug delivery system of p(NIPA/HPMA) hydrogels with loaded acetaminophen was analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy methods. Structural analysis of FTIR spectra indicates that non-covalent intermolecular interactions of the type of hydrogen bonds were formed among functional groups of acetaminophen and side-chains of p(NIPA/HPMA) hydrogels. The surface structure of p(NIPA/HPMA) hydrogels after drug loading indicates the acetaminophen presence into the pores of the hydrogel network, and their loading efficiency was higher than 92%. Qualitative and quantitative analysis of acetaminophen, determined by the high-pressure liquid chromatography method, showed that about 90-99% of the loaded amount was released from p(NIPA/HPMA) hydrogels within 24 h. Kinetic parameters of the acetaminophen release under simulated gastrointestinal conditions were determined. Based on obtained results, the drug delivery system of temperature-sensitive p(NIPA/HPMA) hydrogels with loaded acetaminophen could be suitable for additional investigation for modulated drug administration, e.g., for extended drug administration.

The Formulation of Curcumin: 2-Hydroxypropyl-ß-cyclodextrin Complex with Smart Hydrogel for Prolonged Release of Curcumin.

Curcumin comes from the plant species Curcuma longa and shows numerous pharmacological activities. There are numerous curcumin formulations with gels or cyclodextrins in order to increase its solubility and bioavailability. This paper presents the formulation of complex of curcumin with 2-hydroxypropyl-ß-cyclodextrin in a thermosensitive hydrogel, based on N-isopropylmethacrylamide and N-isopropylacrylamide with ethylene glycol dimethacrylate as a crosslinker. The product was characterized by chemical methods and also by FTIR, HPLC, DSC, SEM, XRD. The results show that synthesis was successfully done. With an increase in the quantity of crosslinker in the hydrogels, the starting release and the release rate of curcumin from the formulation of the complex with hydrogels decreases. The release rate of curcumin from the gel complex formulation is constant over time. It is possible to design a formulation that will release curcumin for more than 60 days. In order to determine the mechanism and kinetics of curcumin release, various mathematical models were applied by using the DDSolver package for Microsoft Excel application. The Korsmeyer-Peppas model best describes the release of curcumin from the gel formulation of the complex, while the values for the diffusion exponent (0.063-0.074) shows that mechanism of the release rate is based on diffusion.

Transformation of synthetic allicin: the influence of ultrasound, microwaves, different solvents and temperatures, and the products isolation.

The transformation of the synthesized allicin, using conventional method, the influence of ultrasound and microwaves, in different organic solvents (acetonitrile, acetone, methanol, and chloroform), at various temperatures (room temperature, 45 °C, and 55 °C) was investigated. Allicin degradation kinetic was monitored by HPLC. Allicin transformation under the effect of microwaves is faster than transformations performed under the influence of ultrasound or by conventional method. Increase of the temperature accelerates allicin transformation. Pharmacologically active compounds of (E)-ajoene, (Z)-ajoene, 3-vinyl-4H-1,2-dithiin, 2-vinyl-4H-1,3-dithiin, and diallyl disulfide were isolated from the mixture of transformation products of allicin under the influence of microwaves in methanol at 55 °C, which is according to kinetic parameters (highest values of the order of reaction and the lowest activation energy) the optimal method.

Curcumin: Biological Activities and Modern Pharmaceutical Forms.

Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione) is a natural lipophilic polyphenol that exhibits significant pharmacological effects in vitro and in vivo through various mechanisms of action. Numerous studies have identified and characterised the pharmacokinetic, pharmacodynamic, and clinical properties of curcumin. Curcumin has an anti-inflammatory, antioxidative, antinociceptive, antiparasitic, antimalarial effect, and it is used as a wound-healing agent. However, poor curcumin absorption in the small intestine, fast metabolism, and fast systemic elimination cause poor bioavailability of curcumin in human beings. In order to overcome these problems, a number of curcumin formulations have been developed. The aim of this paper is to provide an overview of recent research in biological and pharmaceutical aspects of curcumin, methods of sample preparation for its isolation (Soxhlet extraction, ultrasound extraction, pressurised fluid extraction, microwave extraction, enzyme-assisted aided extraction), analytical methods (FTIR, NIR, FT-Raman, UV-VIS, NMR, XRD, DSC, TLC, HPLC, HPTLC, LC-MS, UPLC/Q-TOF-MS) for identification and quantification of curcumin in different matrices, and different techniques for developing formulations. The optimal sample preparation and use of an appropriate analytical method will significantly improve the evaluation of formulations and the biological activity of curcumin.

The Use of Acrylate Polymers in Dentistry.

The manuscript aimed to review the types of acrylate polymers used in dentistry, as well as their chemical, physical, mechanical, and biological properties. Regarding their consistency and purpose, dental acrylate polymers are divided into hard (brittle), which includes acrylates for the production of plate denture bases, obturator prostheses, epitheses and maxillofacial prostheses, their repairs and lining, and soft (flexible), which are used for lining denture bases in special indications. Concerning the composition and method of polymerization initiation, polymers for the production of denture bases are divided into four types: heat-, cold-, light-, and microwave-polymerized. CAD/CAM acrylate dentures are made from factory blocks of dental acrylates and show optimal mechanical and physical properties, undoubtedly better monomer polymerization and thus biocompatibility, and stability of the shape and colour of the base and dentures. Regardless of the number of advantages that these polymers have to offer, they also exhibit certain disadvantages. Technological development enables the enhancement of all acrylate properties to respond better to the demands of the profession. Special attention should be paid to improving the biological characteristics of acrylate polymers, due to reported adverse reactions of patients and dental staff to potentially toxic substances released during their preparation and use.

Antimicrobial Properties of Silver-Modified Denture Base Resins.

The surface quality of denture base resins allows for easy colonization by microorganisms including Candida albicans and Staphylococcus aureus, which cause major diseases of the oral cavity such as denture stomatitis. The widespread use of silver nanoparticles (AgNPs) in various fields of medicine has led to research of their possible application in dentistry, mostly in the prevention of bacterial adhesion, proliferation, and biofilm formation. The aim of the study was to synthesize cold and heat-curing denture base resins modified with AgNPs and AgCl, and evaluate the potential of the modified resins to reduce the growth of C. albicans and S.aureus. The produced material was characterized by Fourier transform infrared spectroscopy (FTIR). The antimicrobial potential of the modified material was demonstrated by the disc-diffusion method, microdilution method, and a modified microdilution method (i.e., disk-diffusion method in broth with viable counting). Spectroscopy confirmed the incorporation of biocidal materials into the structure of the denture base resins. The AgCl and AgNPs modified resins showed an antimicrobial effect. The significance of the study is in the potential therapeutic effects of the modified materials for prevention and threating staphylococci and candida in elderly patients, who are in most cases denture wearers and have a greater susceptibility to develop opportunistic infections. Modified denture base resins can significantly reduce the presence of infection at the point of contact between the denture and the mucous membrane of the prosthetic restoration. Biological tests of modified denture base resins will follow.

Electrospun Poly(lactide) Fibers as Carriers for Controlled Release of Biochanin A.

The aim of this study is to investigate the possibility of using electrospun polylactide (PLA) fibers as a carrier of the phytoestrogen biochanin A. Polylactide fibers were prepared with different contents of biochanin A by using an electrospinning method at specific process parameters. The obtained electrospun polylactide fibers, as carriers of biochanin A, were characterized by means of different methods. The presented results showed that the mechanical properties of PLA have not changed significantly in the presence of biochanin A. Scanning electron microscopy showed that the fine fiber structure is retained without visible deformations and biochanin A crystals on the surface of the fibres. The analysis by infrared spectroscopy showed that there are no strong interactions between polylactide and biochanin A molecules, which is a good prerequisite for the diffusion release of biochanin A from PLA fibers.The release of biochanin A from PLA fibers in buffer solution pH 7.4 at 37 °C was monitored by applying the HPLC method. The rate and time of the release of biochanin A from PLA fibers is in correlation with the amount of the active ingredient in the matrix of the carrier and follows zero-order kinetics. PLA fibers with biochanin A exhibit concentration-dependent activity on proliferation and migration of L929 fibroblasts in direct culture system in vitro, and proved to be suitable for a potential formulation for use in wound healing.

Immunophenotypes of anti-SARS-CoV-2 responses associated with fatal COVID-19.

Background: The relationship between anti-SARS-CoV-2 humoral immune response, pathogenic inflammation, lymphocytes and fatal COVID-19 is poorly understood. Methods: A longitudinal prospective cohort of hospitalised patients with COVID-19 (n=254) was followed up to 35 days after admission (median, 8 days). We measured early anti-SARS-CoV-2 S1 antibody IgG levels and dynamic (698 samples) of quantitative circulating T-, B- and natural killer lymphocyte subsets and serum interleukin-6 (IL-6) response. We used machine learning to identify patterns of the immune response and related these patterns to the primary outcome of 28-day mortality in analyses adjusted for clinical severity factors. Results: Overall, 45 (18%) patients died within 28 days after hospitalisation. We identified six clusters representing discrete anti-SARS-CoV-2 immunophenotypes. Clusters differed considerably in COVID-19 survival. Two clusters, the anti-S1-IgGlowestTlowestBlowestNKmodIL-6mod, and the anti-S1-IgGhighTlowBmodNKmodIL-6highest had a high risk of fatal COVID-19 (HR 3.36-21.69; 95% CI 1.51-163.61 and HR 8.39-10.79; 95% CI 1.20-82.67; p≤0.03, respectively). The anti-S1-IgGhighestTlowestBmodNKmodIL-6mod and anti-S1-IgGlowThighestBhighestNKhighestIL-6low cluster were associated with moderate risk of mortality. In contrast, two clusters the anti-S1-IgGhighThighBmodNKmodIL-6low and anti-S1-IgGhighestThighestBhighNKhighIL-6lowest clusters were characterised by a very low risk of mortality. Conclusions: By employing unsupervised machine learning we identified multiple anti-SARS-CoV-2 immune response clusters and observed major differences in COVID-19 mortality between these clusters. Two discrete immune pathways may lead to fatal COVID-19. One is driven by impaired or delayed antiviral humoral immunity, independently of hyper-inflammation, and the other may arise through excessive IL-6-mediated host inflammation response, independently of the protective humoral response. Those observations could be explored further for application in clinical practice.